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Minootan Z, Wang H, Connaughton P, Lachacz K, Carrigy N, Ordoubadi M, Lechuga-Ballesteros D, Martin AR, Vehring R. On the Feasibility of Rugose Lipid Microparticles in Pressurized Metered Dose Inhalers with Established and New Propellants. AAPS PharmSciTech 2024; 25:82. [PMID: 38600288 DOI: 10.1208/s12249-024-02776-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/21/2024] [Indexed: 04/12/2024] Open
Abstract
Pressurized metered dose inhalers (pMDIs) require optimized formulations to provide stable, consistent lung delivery. This study investigates the feasibility of novel rugose lipid particles (RLPs) as potential drug carriers in pMDI formulations. The physical stability of RLPs was assessed in three different propellants: the established HFA-134a and HFA-227ea and the new low global-warming-potential (GWP) propellant HFO-1234ze. A feedstock containing DSPC and calcium chloride was prepared without pore forming agent to spray dry two RLP batches at inlet temperatures of 55 °C (RLP55) and 75 °C (RLP75). RLPs performance in pMDI formulations was compared to two reference samples that exhibit significantly different performance when suspended in propellants: well-established engineered porous particles and particles containing 80% trehalose and 20% leucine (80T20L). An accelerated stability study at 40 °C and relative humidity of 7% ± 5% was conducted over 3 months. At different time points, a shadowgraphic imaging technique was used to evaluate the colloidal stability of particles in pMDIs. Field emission electron microscopy with energy dispersive X-ray spectroscopy was used to evaluate the morphology and elemental composition of particles extracted from the pMDIs. After 2 weeks, all 80T20L formulations rapidly aggregated upon agitation and exhibited significantly inferior colloidal stability compared to the other samples. In comparison, both the RLP55 and RLP75 formulations, regardless of the propellant used, retained their rugose structure and demonstrated excellent suspension stability comparable with the engineered porous particles. The studied RLPs demonstrate great potential for use in pMDI formulations with HFA propellants and the next-generation low-GWP propellant HFO-1234ze.
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Affiliation(s)
- Zahra Minootan
- Donadeo Innovation Centre for Engineering (DICE), 9211 116 Street NW, Edmonton, Alberta, T6G1H9, Canada
| | - Hui Wang
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G1H9, Canada.
| | - Patrick Connaughton
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Durham, North Carolina, USA
| | - Kellisa Lachacz
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Durham, North Carolina, USA
| | - Nicholas Carrigy
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Durham, North Carolina, USA
| | - Mani Ordoubadi
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G1H9, Canada
| | - David Lechuga-Ballesteros
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Durham, North Carolina, USA
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G1H9, Canada
| | - Reinhard Vehring
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G1H9, Canada
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Christianson CD, Violato E, Sabz M, Rouhani H, Waring T, Martin AR. Improving Breath Detection From Pulsed-Flow Oxygen Sources Using a New Nasal Interface. Respir Care 2024:respcare.11658. [PMID: 38503467 DOI: 10.4187/respcare.11658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
BACKGROUND Patients with COPD and other lung diseases are treated with long-term oxygen therapy (LTOT). Portable oxygen sources are required to administer LTOT while maintaining patient autonomy. Existing portable oxygen equipment has limitations that can hinder patient mobility. A novel nasal interface is presented in this study, aiming to enhance breath detection and triggering efficiency of portable pulsed-flow oxygen devices, thereby improving patient mobility and independence. METHOD To examine the effectiveness of the new interface, 8 respiratory therapists participated in trials using different oxygen sources (tank with oxygen-conserving device, SimplyGo Mini portable oxygen concentrator [POC], and OxyGo NEXT POC) and breathing types (nasal and oral) while using either the new nasal interface or a standard cannula. Each trial was video recorded so participant breaths could be retroactively matched with a pulse/no-pulse response, and triggering success rates were calculated by dividing the number of oxygen pulses by the number of breaths in each trial. After each trial, volunteers were asked to rate their perceived breathing resistance. RESULTS Nasal breathing consistently resulted in higher triggering success rates compared to oral breathing for pulsed-flow oxygen devices. POCs exhibited higher triggering success rates than did the oxygen tanks with conserving device. However, there were no significant differences in triggering success rates between the two POC models. The new nasal interface demonstrated improved triggering success rates compared to the standard cannula. Whereas the new nasal interface was associated with a slight increase in perceived breathing resistance during nasal breathing trials, participants reported manageable resistance levels when using the interface. CONCLUSIONS This study demonstrates that the new nasal interface can improve triggering success rates of pulsed-flow oxygen devices during both nasal and oral breathing scenarios. Further research involving patient trials is recommended to understand the clinical implications of improved pulse triggering.
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Affiliation(s)
- Cole D Christianson
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
| | - Efrem Violato
- Centre for Advanced Medical Simulation, Northern Alberta Institute of Technology, Edmonton, Alberta, Canada
| | - Mozhgan Sabz
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Hossein Rouhani
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Thomas Waring
- Centre for Advanced Medical Simulation, Northern Alberta Institute of Technology, Edmonton, Alberta, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
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3
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Sabz M, Noga ML, Finlay WH, Rouhani H, Martin AR. High-Flow and Low-Flow Oxygen Delivery by Nasal Cannula Evaluated in Infant and Adult Airway Replicas. Respir Care 2024:respcare.11438. [PMID: 38443141 DOI: 10.4187/respcare.11438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
BACKGROUND The nasal cannula is widely regarded as a safe and effective means of administering low- and high-flow oxygen to patients irrespective of their age. However, variability in delivered oxygen concentration (FDO2 ) via nasal cannula has the potential to pose health risks. The present study aimed to evaluate predictive equations for FDO2 over a large parameter space, including variation in breathing, oxygen flow, and upper-airway geometry representative of both young children and adults. METHODS Realistic nasal airway geometries were previously collected from medical scans of adults, infants, and neonates. Nasal airway replicas based on these geometries were used to measure the FDO2 for low-flow oxygen delivery during simulated spontaneous breathing. The present study extends previously published data sets to include higher oxygen flows. The extended data sets included nasal cannula oxygen flows that ranged from 6 to 65 L/min for the adult replicas, and from 0.5 to 6 L/min for the infant replicas. For both age groups, FDO2 was measured over a range of breathing frequencies, inspiratory to expiratory time ratios, and tidal volumes. Measured FDO2 values were compared with values predicted by using a previously derived flow-weighted equation. RESULTS For both age groups, FDO2 was observed to increase nonlinearly with the ratio between oxygen flow supplied to the nasal cannula and the average inhalation flow. The previously derived flow-weighted equation over-predicted FDO2 at higher oxygen flows. A new empirical equation, therefore, was proposed to predict FDO2 for either age group as a function of nasal cannula flow, tidal volume, and inspiratory time. Predicted FDO2 values matched measured values, with average relative errors of 2.4% for infants and 4.3% for adults. CONCLUSIONS A new predictive equation for FDO2 was obtained that accurately matched measured data in both adult and infant airway replicas for low- and high-flow regimens.
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Affiliation(s)
- Mozhgan Sabz
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Michelle L Noga
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Hossein Rouhani
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
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Sabz M, Tavernini S, Pillay K, Christianson C, Noga M, Finlay WH, Rouhani H, Martin AR. Correction to: Variability in low-flow oxygen delivery by nasal cannula evaluated in neonatal and infant airway replicas. Respir Res 2023; 24:94. [PMID: 36973778 PMCID: PMC10045585 DOI: 10.1186/s12931-023-02379-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Affiliation(s)
- Mozhgan Sabz
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Scott Tavernini
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Kineshta Pillay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Cole Christianson
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Michelle Noga
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Hossein Rouhani
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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Tavernini S, Farina DJ, Martin AR, Finlay WH. Using Filters to Estimate Regional Lung Deposition with Pressurized Metered Dose Inhalers. Pharm Res 2022; 39:3371-3380. [PMID: 36348134 DOI: 10.1007/s11095-022-03421-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/15/2022] [Indexed: 11/10/2022]
Abstract
PURPOSE To evaluate the suitability of a recently proposed apparatus that uses filters to directly fractionate the in vitro lung dose into regional deposition estimates for use with pressurized metered dose inhaler (pMDI) devices as a less resource intensive alternative to cascade impaction. METHODS Using three commercially available pMDI devices (Asmanex HFA, Ventolin HFA, QVAR), regional deposition estimates were measured directly using the filter-based apparatus (FBA). Regional deposition estimates were also generated for the same inhalers by performing cascade impaction measurements and inputting the results to an in silico regional deposition model. Regional deposition for each inhaler was evaluated at an inhalation flow rate of 30 and 60 L/min. RESULTS Total recovery of active pharmaceutical ingredient and extrathoracic deposition was independent of method used. The regional deposition estimates provided by each method were similar and captured the same trends. CONCLUSIONS The direct measurement of estimated regional deposition is possible when using the FBA. This method is far less resource intensive than existing methods and so may be useful both for comparison of generic alternatives and the development of innovative products.
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Affiliation(s)
- Scott Tavernini
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | | | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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Ruzycki CA, Tavernini S, Martin AR, Finlay WH. Characterization of dry powder inhaler performance through experimental methods. Adv Drug Deliv Rev 2022; 189:114518. [PMID: 36058349 DOI: 10.1016/j.addr.2022.114518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/17/2022] [Accepted: 08/21/2022] [Indexed: 01/24/2023]
Abstract
Experimental methods provide means for the quality control of existing DPIs and for exploring the influence of formulation and device parameters well in advance of clinical trials for novel devices and formulations. In this review, we examine the state of the art of in vitro testing of DPIs, with a focus primarily on the development of accurate in vitro-in vivo correlations. Aspects of compendial testing are discussed, followed by the influence of flow profiles on DPI performance, the characterization of extrathoracic deposition using mouth-throat geometries, and the characterization of regional thoracic deposition. Additional experimental methods that can inform the timing of bolus delivery, the influence of environmental conditions, and the development of electrostatic charge on aerosolized DPI powders are reviewed. We conclude with perspectives on current in vitro methods and identify potential areas for future investigation, including the estimation of variability in deposition, better characterization of existing compendial methods, optimization of formulation and device design to bypass extrathoracic deposition, and the use of novel tracheobronchial filters that aim to provide more clinically relevant measures of performance directly from in vitro testing.
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Affiliation(s)
- Conor A Ruzycki
- Lovelace Biomedical, 2425 Ridgecrest Drive SE, Albuquerque, NM 87108, USA.
| | - Scott Tavernini
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
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Murphy BM, Chen JZ, Rolo M, Eldam M, Jordan L, Sivananthan SJ, Kinsey R, Guderian JA, Pedersen K, Abhyankar M, Petri WA, Fox CB, Finlay WH, Vehring R, Martin AR. Intranasal delivery of a synthetic Entamoeba histolytica vaccine containing adjuvant (LecA + GLA-3M-052 liposomes): in vitro characterization. Int J Pharm 2022; 626:122141. [PMID: 36058408 DOI: 10.1016/j.ijpharm.2022.122141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/08/2022] [Accepted: 08/21/2022] [Indexed: 11/16/2022]
Abstract
Amebiasis, a disease caused by the parasite Entamoeba histolytica, is estimated to cause millions of infections and at least 55,000 deaths globally each year. With no vaccine currently available, there is an urgent need for an accessible means of stimulating protective mucosal immunity. The objective of this study was to characterize the nasal spray of a novel amebiasis vaccine candidate from a syringe-based liquid atomization device, the Teleflex MAD Nasal™, in both adult and infant nasal airways. Human ergonomic testing was completed to determine realistic actuation parameters. Spray pattern, plume geometry, and droplet size distribution were measured to evaluate reproducibility of free plume characteristics. The Alberta Idealized Nasal Inlet (AINI) and three realistic infant nasal airways were used to determine the in vitro deposition profile in adult and infant airways, respectively. Collectively, in vitro results demonstrated the feasibility of delivering the vaccine candidate to target sites within the nasal airways. Penetration through the nasal airways that could lead to deposition in the lungs was below the limit of quantification for both adult and infant geometries, indicating a low likelihood of adverse events due to lung exposure. These results support continued investigation of intranasal delivery of the synthetic Entamoeba histolytica vaccine.
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Affiliation(s)
- Brynn M Murphy
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - John Z Chen
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | | | | | - Lynn Jordan
- Proveris Scientific, Hudson, MA, United States
| | | | - Robert Kinsey
- Access to Advanced Health Institute (AAHI), Seattle, WA, United States
| | | | | | - Mayuresh Abhyankar
- Department of Medicine, University of Virginia, Charlottesville, VA, United States
| | - William A Petri
- Department of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Christopher B Fox
- Access to Advanced Health Institute (AAHI), Seattle, WA, United States
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Reinhard Vehring
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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8
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Abstract
Traditionally, empirical correlations for predicting respiratory tract deposition of inhaled aerosols have been developed using limited available in vivo data. More recently, advances in medical image segmentation and additive manufacturing processes have allowed researchers to conduct extensive in vitro deposition experiments in realistic replicas of the upper and central branching airways. This work has led to a collection of empirical equations for predicting regional aerosol deposition, especially in the upper, nasal and oral airways. The present section reviews empirical correlations based on both in vivo and in vitro data, which may be used to predict total and regional deposition. Equations are presented for predicting total respiratory deposition fraction, mouth-throat fraction, nasal, and nose-throat fractions for a large variety of aerosol sizes, subject age groups, and breathing maneuvers. Use of these correlations to estimate total lung deposition is also described.
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Affiliation(s)
- Andrew R Martin
- Department of Mechanical Engineering, 10-324 Donadeo Innovation Center for Engineering, University of Alberta, Edmonton, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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9
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Wang H, Ordoubadi M, Connaughton P, Lachacz K, Carrigy N, Tavernini S, Martin AR, Finlay WH, Lechuga-Ballesteros D, Vehring R. Spray Dried Rugose Lipid Particle Platform for Respiratory Drug Delivery. Pharm Res 2022; 39:805-823. [PMID: 35364777 DOI: 10.1007/s11095-022-03242-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/21/2022] [Indexed: 01/13/2023]
Abstract
PURPOSE To develop a new lipid-based particle formulation platform for respiratory drug delivery applications. To find processing conditions for high surface rugosity and manufacturability. To assess the applicability of the new formulation method to different lipids. METHODS A new spray drying method with a simplified aqueous suspension feedstock preparation process was developed for the manufacture of rugose lipid particles of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). A study covering a wide range of feedstock temperatures and outlet temperatures was conducted to optimize the processing conditions. Aerosol performance was characterized in vitro and in silico to assess the feasibility of their use in respiratory drug delivery applications. The applicability of the new spray drying method to longer-chain phospholipids with adjusted spray drying temperatures was also evaluated. RESULTS Highly rugose DSPC lipid particles were produced via spray drying with good manufacturability. A feedstock temperature close to, and an outlet temperature lower than, the main phase transition were identified as critical in producing particles with highly rugose surface features. High emitted dose and total lung dose showed promising aerosol performance of the produced particles for use as a drug loading platform for respiratory drug delivery. Two types of longer-chain lipid particles with higher main phase transition temperatures, 1,2-diarachidoyl-sn-glycero-3-phosphocholine (DAPC) and 1,2-dibehenoyl-sn-glycero-3-phosphocholine (22:0 PC), yielded similar rugose morphologies when spray dried at correspondingly higher processing temperatures. CONCLUSIONS Rugose lipid particles produced via spray drying from an aqueous suspension feedstock are promising as a formulation platform for respiratory drug delivery applications. The new technique can potentially produce rugose particles using various other lipids.
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Affiliation(s)
- Hui Wang
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada
| | - Mani Ordoubadi
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada
| | - Patrick Connaughton
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, South San Francisco, CA, USA
| | - Kellisa Lachacz
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, South San Francisco, CA, USA
| | - Nicholas Carrigy
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, South San Francisco, CA, USA
| | - Scott Tavernini
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada
| | - David Lechuga-Ballesteros
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, South San Francisco, CA, USA
| | - Reinhard Vehring
- Department of Mechanical Engineering, University of Alberta, Alberta, Canada.
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10
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Sabz M, Tavernini S, Pillay K, Christianson C, Noga M, Finlay WH, Rouhani H, Martin AR. Variability in low-flow oxygen delivery by nasal cannula evaluated in neonatal and infant airway replicas. Respir Res 2022; 23:333. [PMID: 36482438 PMCID: PMC9730608 DOI: 10.1186/s12931-022-02260-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The nasal cannula is considered a trusted and effective means of administering low-flow oxygen and is widely used for neonates and infants requiring oxygen therapy, despite an understanding that oxygen concentrations delivered to patients are variable. METHODS In the present study, realistic nasal airway replicas derived from medical scans of children less than 3 months old were used to measure the fraction of oxygen inhaled (FiO2) through nasal cannulas during low-flow oxygen delivery. Parameters influencing variability in FiO2 were evaluated, as was the hypothesis that measured FiO2 values could be predicted using a simple, flow-weighted calculation that assumes ideal mixing of oxygen with entrained room air. Tidal breathing through neonatal and infant nasal airway replicas was controlled using a lung simulator. Parameters for nasal cannula oxygen flow rate, nasal airway geometry, tidal volume, respiratory rate, inhalation/exhalation, or I:E ratio (ti/te), breath waveform, and cannula prong insertion position were varied to determine their effect on measured FiO2. In total, FiO2 was measured for 384 different parameter combinations, with each combination repeated in triplicate. Analysis of variance (ANOVA) was used to assess the influence of parameters on measured FiO2. RESULTS Measured FiO2 was not appreciably affected by the breath waveform shape, the replica geometry, or the cannula position but was significantly influenced by the tidal volume, the inhalation time, and the nasal cannula flow rate. CONCLUSIONS The flow-weighted calculation overpredicted FiO2 for measured values above 60%, but an empirical correction to the calculation provided good agreement with measured FiO2 across the full range of experimental data.
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Affiliation(s)
- Mozhgan Sabz
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Scott Tavernini
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Kineshta Pillay
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Cole Christianson
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Michelle Noga
- grid.17089.370000 0001 2190 316XDepartment of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB Canada
| | - Warren H. Finlay
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Hossein Rouhani
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
| | - Andrew R. Martin
- grid.17089.370000 0001 2190 316XDepartment of Mechanical Engineering, University of Alberta, Edmonton, AB Canada
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11
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Farnoud A, Tofighian H, Baumann I, Martin AR, Rashidi MM, Menden MP, Schmid O. Pulsatile Bi-Directional Aerosol Flow Affects Aerosol Delivery to the Intranasal Olfactory Region: A Patient-Specific Computational Study. Front Pharmacol 2021; 12:746420. [PMID: 34887754 PMCID: PMC8650014 DOI: 10.3389/fphar.2021.746420] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
The nasal olfactory region is a potential route for non-invasive delivery of drugs directly from the nasal epithelium to the brain, bypassing the often impermeable blood-brain barrier. However, efficient aerosol delivery to the olfactory region is challenging due to its location in the nose. Here we explore aerosol delivery with bi-directional pulsatile flow conditions for targeted drug delivery to the olfactory region using a computational fluid dynamics (CFD) model on the patient-specific nasal geometry. Aerosols with aerodynamic diameter of 1 µm, which is large enough for delivery of large enough drug doses and yet potentially small enough for non-inertial aerosol deposition due to, e.g., particle diffusion and flow oscillations, is inhaled for 1.98 s through one nostril and exhaled through the other one. The bi-directional aerosol delivery with steady flow rate of 4 L/min results in deposition efficiencies (DEs) of 50.9 and 0.48% in the nasal cavity and olfactory region, respectively. Pulsatile flow with average flow rate of 4 L/min (frequency: 45 Hz) reduces these values to 34.4 and 0.12%, respectively, and it mitigates the non-uniformity of right-left deposition in both the cavity (from 1.77- to 1.33-fold) and the olfactory region (from 624- to 53.2-fold). The average drug dose deposited in the nasal cavity and the olfactory epithelium region is very similar in the right nasal cavity independent of pulsation conditions (inhalation side). In contrast, the local aerosol dose in the olfactory region of the left side is at least 100-fold lower than that in the nasal cavity independent of pulsation condition. Hence, while pulsatile flow reduces the right-left (inhalation-exhalation) imbalance, it is not able to overcome it. However, the inhalation side (even with pulsation) allows for relatively high olfactory epithelium drug doses per area reaching the same level as in the total nasal cavity. Due to the relatively low drug deposition in olfactory region on the exhalation side, this allows either very efficient targeting of the inhalation side, or uniform drug delivery by performing bidirectional flow first from the one and then from the other side of the nose.
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Affiliation(s)
- Ali Farnoud
- Institute of Computational Biology, Helmholtz Zentrum München, Munich, Germany.,Comprehensive Pneumology Center, Member of the German Center for Lung Research, Munich, Germany.,Institute of Lung Biology and Disease, Helmholtz Zentrum München, Munich, Germany
| | - Hesam Tofighian
- Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran
| | - Ingo Baumann
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical Center of Heidelberg University, Heidelberg, Germany
| | - Andrew R Martin
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Mohammad M Rashidi
- Institute of Fundamental and Frontier Sciences, University of Electronics and Technology of China, Chengdu, China
| | - Micheal P Menden
- Institute of Computational Biology, Helmholtz Zentrum München, Munich, Germany.,Department of Biology, Ludwig-Maximilians University Munich, Munich, Germany.,German Center for Diabetes Research (DZD e.V.), Munich, Germany
| | - Otmar Schmid
- Comprehensive Pneumology Center, Member of the German Center for Lung Research, Munich, Germany.,Institute of Lung Biology and Disease, Helmholtz Zentrum München, Munich, Germany
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12
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Christianson C, Pillay K, Chen JZ, Finlay W, Martin AR. In Vitro Evaluation of a Nasal Interface Used to Improve Delivery from a Portable Oxygen Concentrator. J Med Device 2021. [DOI: 10.1115/1.4053115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Abstract
Portable oxygen concentrators (POCs) are widely used to administer long-term oxygen therapy (LTOT) and employ pulsed delivery modes to conserve oxygen. Efficient pulsed delivery requires that POCs are triggered by patient inhalation. Triggering is known to fail for some patients during periods of quite breathing, as occurs during sleep. The present article describes a new nasal interface designed to improve triggering of pulsed oxygen delivery from portable oxygen concentrators (POCs). In vitro experiments incorporating realistic nasal airway replicas and simulated breathing were conducted. The pressure monitored via oxygen supply tubing (the signal pressure) was measured over a range of constant inhalation flow rates with the nasal interface inserted into the nares of the nasal airway replicas, and compared with signal pressures measured for standard and flared nasal cannulas. Triggering efficiency and the fraction of inhaled oxygen (FiO2) were then evaluated for the nasal interface and cannulas used with a commercial POC during simulated tidal breathing through the replicas. Higher signal pressures were achieved for the nasal interface than for nasal cannulas at all flow rates studied. The nasal interface triggered pulsed delivery from the POC in cases where nasal cannulas failed to trigger. FiO2 was significantly higher for successful triggering cases than for failed triggering cases. The nasal interface improved triggering of pulsed oxygen delivery from a POC and presents a simple solution that could be used with commercially-available POCs to reliably supply oxygen during periods of quiet breathing.
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Affiliation(s)
- Cole Christianson
- University of Alberta, Department of Mechanical Engineering, Edmonton, Alberta, Canada T6G 1H9
| | - Kineshta Pillay
- University of Alberta, Department of Mechanical Engineering, Edmonton, Alberta, Canada T6G 1H9
| | - John Z Chen
- University of Alberta, Department of Mechanical Engineering, Edmonton, Alberta, Canada T6G 1H9
| | - Warren Finlay
- University of Alberta, Department of Mechanical Engineering, Edmonton, Alberta, Canada T6G 1H9
| | - Andrew R. Martin
- University of Alberta, Department of Mechanical Engineering, Edmonton, Alberta, Canada T6G 1H9
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13
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Duong K, Noga M, MacLean JE, Finlay WH, Martin AR. Comparison of airway pressures and expired gas washout for nasal high flow versus CPAP in child airway replicas. Respir Res 2021; 22:289. [PMID: 34758818 PMCID: PMC8579677 DOI: 10.1186/s12931-021-01880-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/27/2021] [Indexed: 01/22/2023] Open
Abstract
Background For children and adults, the standard treatment for obstructive sleep apnea is the delivery of continuous positive airway pressure (CPAP). Though effective, CPAP masks can be uncomfortable to patients, contributing to adherence concerns. Recently, nasal high flow (NHF) therapy has been investigated as an alternative, especially in CPAP-intolerant children. The present study aimed to compare and contrast the positive airway pressures and expired gas washout generated by NHF versus CPAP in child nasal airway replicas. Methods NHF therapy was investigated at a flow rate of 20 L/min and compared to CPAP at 5 cmH2O and 10 cmH2O for 10 nasal airway replicas, built from computed tomography scans of children aged 4–8 years. NHF was delivered with three different high flow nasal cannula models provided by the same manufacturer, and CPAP was delivered with a sealed nasal mask. Tidal breathing through each replica was imposed using a lung simulator, and airway pressure at the trachea was recorded over time. For expired gas washout measurements, carbon dioxide was injected at the lung simulator, and end-tidal carbon dioxide (EtCO2) was measured at the trachea. Changes in EtCO2 compared to baseline values (no intervention) were assessed. Results NHF therapy generated an average positive end-expiratory pressure (PEEP) of 5.17 ± 2.09 cmH2O (mean ± SD, n = 10), similar to PEEP of 4.95 ± 0.03 cmH2O generated by nominally 5 cmH2O CPAP. Variation in tracheal pressure was higher between airway replicas for NHF compared to CPAP. EtCO2 decreased from baseline during administration of NHF, whereas it increased during CPAP. No statistical difference in tracheal pressure nor EtCO2 was found between the three high flow nasal cannulas. Conclusion In child airway replicas, NHF at 20 L/min generated average PEEP similar to CPAP at 5 cm H2O. Variation in tracheal pressure was higher between airway replicas for NHF than for CPAP. The delivery of NHF yielded expired gas washout, whereas CPAP impeded expired gas washout due to the increased dead space of the sealed mask. Supplementary Information The online version contains supplementary material available at 10.1186/s12931-021-01880-z.
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Affiliation(s)
- Kelvin Duong
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Michelle Noga
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Canada
| | - Joanna E MacLean
- Department of Pediatrics and Women & Children's Health Research Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada.,Stollery Children's Hospital, Edmonton, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada. .,10-324 Innovation Centre for Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
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Clapp PW, Ruzycki CA, Samet JM, Zeman KL, Berntsen J, Sickbert-Bennett E, Weber DJ, Finlay WH, Martin AR, Bennett WD, Wilson KH. A simple HEPA filtering facepiece. Am J Infect Control 2021; 49:1206-1209. [PMID: 33971283 DOI: 10.1016/j.ajic.2021.04.085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 01/12/2023]
Abstract
Shortages of efficient filtering facepiece respirators leave the public vulnerable to transmission of infectious diseases in small particle aerosols. This study demonstrates that a high-filtration-efficiency facepiece capable of filtering out >95% of 0.05μm particles while being worn can be simply produced with available materials.
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Seo S, Ruzycki CA, Johnson B, Wang H, Vehring R, Romanyk D, Finlay WH, Martin AR. Size-Specific Filtration Performance of N95 Respirators After Decontamination by Moist Heat Incubation. J Aerosol Med Pulm Drug Deliv 2021; 35:41-49. [PMID: 34374572 DOI: 10.1089/jamp.2021.0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Decontamination and reuse of respirators have been proposed to mitigate the shortage of respirators during pandemics. The U.S. National Institute for Occupational Safety and Health (NIOSH)'s respirator filtration efficiency (FE) test has been used to confirm that decontamination procedures maintain minimum FE above 95% for N95s and similar respirators. However, it was hypothesized that the limited range of test particle sizes may not include the most penetrating particle size (MPPS) for all respirators, especially after decontamination by moist heat incubation (MHI). Materials and Methods: A custom-designed apparatus was used to measure size-specific FE for respirators across particle size bins between aerodynamic diameter of 0.07 and 1.97 μm using an electrical low-pressure impactor. FEs were measured for two N95 respirator models before and after 10 cycles of MHI. In addition, pressure drop through the respirator materials and scanning electron microscope (SEM) images of respirator layers were obtained before and after MHI. Results: For Kimtech™ brand N95 respirators, FE was not reduced at any size after MHI. For Safe Life brand N95s, FE was below 95% before MHI and decreased significantly after MHI. The MPPS for this respirator was outside the range defined in NIOSH test protocol, and increased after MHI. There was no appreciable change to the pressure drop through the two respirator models after MHI, nor was any deterioration in fiber integrity visible in SEM images. Conclusions: Based on the results of the present study and other studies in the literature, MHI can be used to decontaminate respirators without significant decrease in FE. However, potential effects of MHI on FE need to be assessed for each respirator model. The ability to evaluate size-specific FE across a wide range of particle sizes is important in identifying the MPPS and associated FE of respirators before and after MHI.
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Affiliation(s)
- Solbee Seo
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Conor A Ruzycki
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Bailey Johnson
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Hui Wang
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Reinhard Vehring
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Dan Romanyk
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Warren H Finlay
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R Martin
- The Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
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Chen J, Martin AR, Finlay WH. Recent In Vitro and In Silico Advances in the Understanding of Intranasal Drug Delivery. Curr Pharm Des 2021; 27:1482-1497. [PMID: 33183191 DOI: 10.2174/1381612826666201112143230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/02/2020] [Accepted: 10/06/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Many drugs are delivered intranasally for local or systemic effect, typically in the form of droplets or aerosols. Due to the high cost of in vivo studies, drug developers and researchers often turn to in vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways. OBJECTIVE The study aims to perform a summary of advances in the understanding of intranasal drug delivery based on recent in vitro and in silico studies. CONCLUSION The turbinates are a common target for local drug delivery applications, and while nasal sprays are able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning optimal parameters for device design, formulation properties and patient technique which would maximize turbinate deposition. Nebulizers can more easily target the turbinates, but come with the disadvantage of significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for the potential treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal delivery will be useful in the development of the next generation of intranasal drug delivery devices.
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Affiliation(s)
- John Chen
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
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17
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Loreto CD, Monge O, Martin AR, Ochoa-Herrera V, Sierra-Alvarez R, Almendariz FJ. Effect of carbon source and metal toxicity for potential acid mine drainage (AMD) treatment with an anaerobic sludge using sulfate-reduction. Water Sci Technol 2021; 83:2669-2677. [PMID: 34115621 DOI: 10.2166/wst.2021.163] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study compares sulfate-reduction performance in an anaerobic sludge with different carbon sources (ethanol, acetate, and glucose). Also, the toxic effect of copper was evaluated to assess its feasibility for possible acid mine drainage (AMD) treatment. Serological bottles with 1.5 g VSS/L and 150 mL of basal medium (0.67 g COD/g SO42- at a 7-8 pH) were used to determine the percentage of electron equivalents, maximum specific methanogenic (SMA), and sulfide generation activities (SGA). The copper effect was evaluated in a previously activated sludge in batch bioassays containing different concentrations of copper (0-50 mg/L), 3 gVSS/L, and 150 mL of basal medium (0.67 g COD/g SO42-). Carbon source bioassays with glucose obtained the best results in terms of the SGA (1.73 ± 0.34 mg S2-/g VSS•d) and SMA (10.41 mg COD-CH4/g VSS•d). The electron flow in the presence of glucose also indicated that 21.29 ± 5.2% of the metabolic activity of the sludge was directed towards sulfidogenesis. Copper toxicity bioassays indicated that a considerable decline in metabolic activity occurs above 10 mg/L. The 20%IC, 50%IC, and 80%IC were 4.5, 14.94, and 35.31 mg Cu/L. Compared to the other carbon sources tested, glucose proved to be a suitable electron donor since it favors sulfidogenesis. Finally, copper concentrations above 15 mg/L inhibited metabolic activity in the toxicity bioassays.
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Affiliation(s)
- C D Loreto
- Department of Chemical Engineering and Metallurgy, University of Sonora, Rosales and Luis Encinas Blvd., Hermosillo, Sonora, Mexico E-mail:
| | - O Monge
- Department of Chemical Engineering and Metallurgy, University of Sonora, Rosales and Luis Encinas Blvd., Hermosillo, Sonora, Mexico E-mail:
| | - A R Martin
- Department of Chemical Engineering and Metallurgy, University of Sonora, Rosales and Luis Encinas Blvd., Hermosillo, Sonora, Mexico E-mail:
| | - V Ochoa-Herrera
- Colegio de Ciencias e Ingenierías, Instituto Biósfera, Universidad San Francisco de Quito, Diego Robleas y Via Interoceanica, Quito, Ecuador and Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - R Sierra-Alvarez
- Department of Chemical and Environmental Engineering, University of Arizona, 210011, Tucson, Arizona, USA
| | - F J Almendariz
- Department of Chemical Engineering and Metallurgy, University of Sonora, Rosales and Luis Encinas Blvd., Hermosillo, Sonora, Mexico E-mail:
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Abstract
BACKGROUND Inhaled nitric oxide (NO) is most frequently delivered to mechanically ventilated patients in critical care, but it can also be administered noninvasively. The delivered dose and efficiency of continuous flow NO supplied through a nasal cannula has yet to be established. This study aimed to determine the influence of nasal cannula type, supply flow, and breathing pattern on delivered NO using a realistic adult airway replica and lung simulator. METHODS Simulated breathing patterns were selected to represent rest, sleep, and light exercise, and were varied to investigate the effects of tidal volume and breathing frequency independently. Supplied gas flows targeted tracheal concentrations at rest of 5 or 20 ppm NO and were supplied with 2 L/min O2. Three different cannulas were tested. Tracheal NO concentrations and NO mass flow past the trachea were evaluated. RESULTS Cannula type had a minor influence on delivered dose. Tracheal NO concentrations differed significantly based on breathing pattern (P < 0.01); for a target NO concentration of 20 ppm at rest, average inhaled NO concentrations were 23.3 ± 0.5 ppm, 36.5 ± 1.4 ppm, and 17.2 ± 0.3 ppm for the rest, sleep, and light exercise breathing patterns, respectively. For the same test conditions, mass flow of NO past the trachea was less sensitive to breathing pattern: 20.3 ± 0.5 mg/h, 19.9 ± 0.8 mg/h, and 24.3 ± 0.4 mg/h for the rest, sleep, and light exercise breathing patterns, respectively. Mass flow and delivery efficiency increased when minute volume increased. CONCLUSIONS These results indicate that inhaled NO concentration is strongly influenced by breathing pattern, whereas inhaled NO mass flow is not. NO mass flow may therefore be a useful dose metric for continuous flow delivery via nasal cannula.
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Affiliation(s)
- Kineshta Pillay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - John Z Chen
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
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Affiliation(s)
- Andrew R. Martin
- 10-324 Donadeo Innovation Center for Engineering, University of Alberta, Alberta, Canada
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20
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Duong K, Glover J, Perry AC, Olmstead D, Ungrin M, Colarusso P, MacLean JE, Martin AR. Feasibility of three-dimensional facial imaging and printing for producing customised nasal masks for continuous positive airway pressure. ERJ Open Res 2021; 7:00632-2020. [PMID: 33569497 PMCID: PMC7861025 DOI: 10.1183/23120541.00632-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/16/2020] [Indexed: 11/18/2022] Open
Abstract
Rationale Delivery of continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnoea in children and adults. Treatment adherence is a major challenge, as many patients find the CPAP mask uncomfortable. The study aim was to demonstrate the feasibility of delivered CPAP through customised nasal masks by assessing mask leak and comfort of customised masks compared to commercially available CPAP masks. Methods Six healthy adult volunteers participated in a crossover study including commercial masks in three different sizes (petite, small/medium and large) from the same supplier and a customised mask fabricated for each subject using three-dimensional facial scanning and modern additive manufacturing processes. Mask leak and comfort were assessed with varying CPAP levels and mask tightness. Leak was measured in real time using an inline low-resistance Pitot tube flow sensor, and each mask was ranked for comfort by the subjects. Results Mask leak rates varied directly with CPAP level and inversely with mask tightness. When ranked for comfort, three subjects favoured the customised mask, while three favoured a commercial mask. The petite mask yielded the highest mask leaks and was ranked least comfortable by all subjects. Relative mask leaks and comfort rankings for the other commercial and customised masks varied between individuals. Mask leak was comparable when comparing the customised masks with the highest ranked commercial masks. Conclusion Customised masks successfully delivered target CPAP settings in all six subjects, demonstrating the feasibility of this approach. This research details a methodology for fabrication of customised noninvasive ventilation masks based on 3D facial scans to use as an alternative to commercially available masks for the delivery of continuous positive airway pressurehttps://bit.ly/35WspAg
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Affiliation(s)
- Kelvin Duong
- Dept of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Joel Glover
- Live Cell Imaging Laboratory, Dept of Physiology and Pharmacology and the Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Alexander C Perry
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | | | - Mark Ungrin
- Dept of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Biomedical Engineering Graduate Program, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Pina Colarusso
- Live Cell Imaging Laboratory, Dept of Physiology and Pharmacology and the Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Joanna E MacLean
- Dept of Pediatrics and Women & Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta, Stollery Children's Hospital, Edmonton, Canada
| | - Andrew R Martin
- Dept of Mechanical Engineering, University of Alberta, Edmonton, Canada
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21
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Moore C, Rebstock D, Katz IM, Noga ML, Caillibotte G, Finlay WH, Martin AR. The influence of flowrate and gas density on positive airway pressure for high flow nasal cannula applied to infant airway replicas. J Biomech 2020; 112:110022. [PMID: 32942204 DOI: 10.1016/j.jbiomech.2020.110022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/31/2020] [Accepted: 08/26/2020] [Indexed: 01/09/2023]
Abstract
High flow nasal cannula (HFNC) therapy has been previously shown to produce positive upper airway pressures in adult and child patients. This work aimed to evaluate and quantify the effects of HFNC flowrate and gas type on airway pressures measured in vitro in infant airway replicas. Ten realistic infant airway replicas, extending from nares to trachea, were connected in turn to a lung simulator and were supplied gas flows through HFNC. Air and heliox were each provided at two weight-indexed flowrates, 1 l/min/kg and 2 l/min/kg. Pressure and lung volume were continuously measured during simulated breathing. For constant simulated patient effort, no statistically significant change in tidal volume was measured between baseline and lower or higher HFNC flowrates, nor was there any significant difference in tidal volume between air and heliox. Tracheal pressure increased with increasing HFNC flow rate, and was highly variable between airway replicas. Higher pressures were measured for air versus heliox. For air supplied at 2 l/min/kg, average airway pressures in excess of 4 cm H2O were generated, with positive end-expiratory pressure (PEEP) ranging from 2.5 to nearly 12 cm H2O across the replicas. A predictive correlation for PEEP was proposed based on supplied gas density and flow velocities exiting the cannula and nares, and was able to account for a portion of variability between airway replicas (R2 = 0.913). Additionally, PEEP was well correlated with, and predictive of, expiratory peak pressure (R2 = 0.939) and average inspiratory pressure (R2 = 0.944).
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Affiliation(s)
- Charles Moore
- Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Douglas Rebstock
- Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Ira M Katz
- Medical R&D, Air Liquide Santé International, Paris-Saclay Research Center, Les Loges-en-Josas, France
| | - Michelle L Noga
- Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada
| | - Georges Caillibotte
- Medical R&D, Air Liquide Santé International, Paris-Saclay Research Center, Les Loges-en-Josas, France
| | - Warren H Finlay
- Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Martin
- Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
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Ruzycki CA, Murphy B, Nathoo H, Finlay WH, Martin AR. Combined in Vitro-in Silico Approach to Predict Deposition and Pharmacokinetics of Budesonide Dry Powder Inhalers. Pharm Res 2020; 37:209. [PMID: 32995953 DOI: 10.1007/s11095-020-02924-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 09/02/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE A combined in vitro - in silico methodology was designed to estimate pharmacokinetics of budesonide delivered via dry powder inhaler. METHODS Particle size distributions from three budesonide DPIs, measured with a Next Generation Impactor and Alberta Idealized Throat, were input into a lung deposition model to predict regional deposition. Subsequent systemic exposure was estimated using a pharmacokinetic model that incorporated Nernst-Brunner dissolution in the conducting airways to predict the net influence of dissolution, mucociliary clearance, and absorption. RESULTS DPIs demonstrated significant in vitro differences in deposition, resulting in large differences in simulated regional deposition in the central conducting airways and the alveolar region. Similar but low deposition in the small conducting airways was observed with each DPI. Pharmacokinetic predictions showed good agreement with in vivo data from the literature. Peak systemic concentration was tied primarily to the alveolar dose, while the area under the curve was more dependent on the total lung dose. Tracheobronchial deposition was poorly correlated with pharmacokinetic data. CONCLUSIONS Combination of realistic in vitro experiments, lung deposition modeling, and pharmacokinetic modeling was shown to provide reasonable estimation of in vivo systemic exposure from DPIs. Such combined approaches are useful in the development of orally inhaled drug products.
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Affiliation(s)
- Conor A Ruzycki
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Brynn Murphy
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Hafeez Nathoo
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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Fink JB, Ehrmann S, Li J, Dailey P, McKiernan P, Darquenne C, Martin AR, Rothen-Rutishauser B, Kuehl PJ, Häussermann S, MacLoughlin R, Smaldone GC, Muellinger B, Corcoran TE, Dhand R. Reducing Aerosol-Related Risk of Transmission in the Era of COVID-19: An Interim Guidance Endorsed by the International Society of Aerosols in Medicine. J Aerosol Med Pulm Drug Deliv 2020; 33:300-304. [PMID: 32783675 PMCID: PMC7757542 DOI: 10.1089/jamp.2020.1615] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
National and international guidelines recommend droplet/airborne transmission and contact precautions for those caring for coronavirus disease 2019 (COVID-19) patients in ambulatory and acute care settings. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, an acute respiratory infectious agent, is primarily transmitted between people through respiratory droplets and contact routes. A recognized key to transmission of COVID-19, and droplet infections generally, is the dispersion of bioaerosols from the patient. Increased risk of transmission has been associated with aerosol generating procedures that include endotracheal intubation, bronchoscopy, open suctioning, administration of nebulized treatment, manual ventilation before intubation, turning the patient to the prone position, disconnecting the patient from the ventilator, noninvasive positive-pressure ventilation, tracheostomy, and cardiopulmonary resuscitation. The knowledge that COVID-19 subjects can be asymptomatic and still shed virus, producing infectious droplets during breathing, suggests that health care workers (HCWs) should assume every patient is potentially infectious during this pandemic. Taking actions to reduce risk of transmission to HCWs is, therefore, a vital consideration for safe delivery of all medical aerosols. Guidelines for use of personal protective equipment (glove, gowns, masks, shield, and/or powered air purifying respiratory) during high-risk procedures are essential and should be considered for use with lower risk procedures such as administration of uncontaminated medical aerosols. Bioaerosols generated by infected patients are a major source of transmission for SARS CoV-2, and other infectious agents. In contrast, therapeutic aerosols do not add to the risk of disease transmission unless contaminated by patients or HCWs.
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Affiliation(s)
- James B Fink
- Aerogen Pharma Corp., San Mateo, California, USA.,Division of Respiratory Care, Department of Cardiopulmonary Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Stephan Ehrmann
- CHRU Tours, Médecine Intensive Réanimation, CIC INSERM 1415, CRICS-TriggerSep Research Network, Tours, France.,INSERM, Centre d'étude des Pathologies Respiratoires, U1100, Université de Tours, Tours, France
| | - Jie Li
- Division of Respiratory Care, Department of Cardiopulmonary Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | | | | | - Chantal Darquenne
- Department of Medicine, University of California, San Diego, California, USA
| | - Andrew R Martin
- Mechanical Engineering, University of Alberta, Edmonton, Canada
| | | | | | | | - Ronan MacLoughlin
- Aerogen Limited, Galway, Ireland.,School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons, Dublin, Ireland.,School of Pharmacy and Pharmaceutical Sciences, Trinity College, Dublin, Ireland
| | - Gerald C Smaldone
- Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, State University of New York at Stony Brook, Stony Brook, New York, USA
| | | | - Timothy E Corcoran
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rajiv Dhand
- Department of Medicine, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, Tennessee, USA
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Chen JZ, Kiaee M, Martin AR, Finlay WH. In vitro assessment of an idealized nose for nasal spray testing: Comparison with regional deposition in realistic nasal replicas. Int J Pharm 2020; 582:119341. [DOI: 10.1016/j.ijpharm.2020.119341] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/07/2020] [Accepted: 04/14/2020] [Indexed: 12/24/2022]
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25
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Ruzycki CA, Martin AR, Finlay WH. An Exploration of Factors Affecting In Vitro Deposition of Pharmaceutical Aerosols in the Alberta Idealized Throat. J Aerosol Med Pulm Drug Deliv 2019; 32:405-417. [DOI: 10.1089/jamp.2019.1531] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Conor A. Ruzycki
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R. Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Warren H. Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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Robeck TR, Amaral RS, da Silva VMF, Martin AR, Montano GA, Brown JL. Thyroid hormone concentrations associated with age, sex, reproductive status and apparent reproductive failure in the Amazon river dolphin ( Inia geoffrensis). Conserv Physiol 2019; 7:coz041. [PMID: 31384468 PMCID: PMC6669313 DOI: 10.1093/conphys/coz041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/06/2019] [Accepted: 06/11/2019] [Indexed: 06/10/2023]
Abstract
This study was conducted to characterize immunoreactive thyroid hormone concentrations in wild Amazon river dolphins, also called boto (Inia geoffrensis) by age group, sex, pregnancy and lactation status, and to determine if thyroid hormone concentration differences could be detected between pregnant females with and without successful parturition outcomes. Radioimmunoassays were used to analyse total T 3 and total T 4 in 182 serum samples collected from 172 botos living in the Mamirauá Sustainable Development Reserve, in the Brazilian Amazon from 2003 through 2015. Age significantly affected tT 3 and tT 4 concentrations in males, with values in immature males and females being significantly lower than those in adult males, whereas no age effects were noted between immature females and adult non-pregnant, non-lactating females. Significant sex differences were noted in tT 3 concentrations between immature males and females and in tT 4 concentrations between adult males and females. These resulted in significant differences in the tT 3:tT 4 ratio between males and females within the immature and adult groups. Lactating and non-pregnant adult females had significantly higher tT 3 concentrations than pregnant females, and this difference was primarily driven by a 12% drop in tT 3 concentrations during the last two-thirds of pregnancy. No differences in thyroid hormone concentrations were detected between females diagnosed as pregnant and later found to have or not have a live calf. These results are the first to define thyroid hormone reference intervals and normal physiological variations in a wild population of river dolphins.
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Affiliation(s)
- T R Robeck
- Species Preservation Laboratory, SeaWorld Parks and Entertainment, 2595 Ingraham Rd, San Diego, CA 92109, USA
| | - R S Amaral
- Federal Institute of Education, Science and Technology of Amazonas—IFAM/CMZL, Av. Cosme Ferreira 8045, Manaus 69086-475, Brazil
| | - V M F da Silva
- Laboratory of Aquatic Mammals, National Institute of Amazonian Research—INPA, Av Andre Araujo 2936, Manaus 69067-375, Brazil
| | - A R Martin
- Centre for Remote Environments, University of Dundee, Nethergate, Dundee DD1 4HN, UK
| | - G A Montano
- Species Preservation Laboratory, SeaWorld Parks and Entertainment, 2595 Ingraham Rd, San Diego, CA 92109, USA
| | - J L Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA
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Katz I, Chen J, Duong K, Zhu K, Pichelin M, Caillibotte G, Martin AR. Dose variability of supplemental oxygen therapy with open patient interfaces based on in vitro measurements using a physiologically realistic upper airway model. Respir Res 2019; 20:149. [PMID: 31299963 PMCID: PMC6625031 DOI: 10.1186/s12931-019-1104-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 06/18/2019] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Supplemental oxygen therapy is widely used in hospitals and in the home for chronic care. However, there are several fundamental problems with the application of this therapy such that patients are often exposed to arterial oxygen concentrations outside of the intended target range. This paper reports volume-averaged tracheal oxygen concentration measurements (FtO2) from in vitro experiments conducted using a physiologically realistic upper airway model. The goal is to provide data to inform a detailed discussion of the delivered oxygen dose. METHODS A baseline FtO2 dataset using a standard, straight adult nasal cannula was established by varying tidal volume (Vt), breathing frequency (f), and continuous oxygen flow rate (QO2) between the following levels to create a factorial design: Vt = 500, 640, or 800 ml; f = 12, 17, or 22 min- 1; QO2 = 2, 4, or 6 l/min. Further experiments were performed to investigate the influence on FtO2 of variation in inspiratory/expiratory ratio, inclusion of an inspiratory or expiratory pause, patient interface selection (e.g. nasal cannula versus a facemask), and rapid breathing patterns in comparison with the baseline measurements. RESULTS Oxygen concentration measured at the trachea varied by as much as 60% (i.e. from 30.2 to 48.0% of absolute oxygen concentration) for the same oxygen supply flow rate due to variation in simulated breathing pattern. Among the baseline cases, the chief reasons for variation were 1) the influence of variation in tidal volume leading to variable FiO2 and 2) variation in breathing frequency affecting volume of supplemental oxygen delivered through the breath. CONCLUSION For oxygen administration using open patient interfaces there was variability in the concentration and quantity of oxygen delivered to the trachea over the large range of scenarios studied. Of primary importance in evaluating the oxygen dose is knowledge of the breathing parameters that determine the average inhalation flow rate relative to the oxygen flow rate. Otherwise, the oxygen dose cannot be determined.
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Affiliation(s)
- Ira Katz
- Medical R&D, Air Liquide Santé International, Paris Innovation Campus, Les loges-en-Josas, France
| | - John Chen
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Kelvin Duong
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | | | - Marine Pichelin
- Technical Innovation, Air Liquide Santé International, Paris Innovation Campus, Les Loges-en-Josas, France
| | - Georges Caillibotte
- Technical Innovation, Air Liquide Santé International, Paris Innovation Campus, Les Loges-en-Josas, France
| | - Andrew R. Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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Moore CP, Katz IM, Caillibotte G, Finlay WH, Martin AR. Correlation of high flow nasal cannula outlet area with gas clearance and pressure in adult upper airway replicas. Clin Biomech (Bristol, Avon) 2019; 66:66-73. [PMID: 29174453 DOI: 10.1016/j.clinbiomech.2017.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/02/2017] [Accepted: 11/07/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Primary benefits of high flow nasal cannula therapy include washout of carbon dioxide rich exhaled gas and increased airway pressures during tidal breathing. This work reports on the influence of high flow nasal cannula outlet area on upper airways gas clearance and tracheal pressures using measurements in five realistic adult nose-throat airway replicas. METHODS Two commercial high flow nasal cannulas and one generic nasal cannula of varying size were compared. 100% oxygen was supplied via cannulas at flow rates ranging from 30 to 90l/min to replicas originally filled with air, and oxygen concentrations at the larynx and trachea were compared over time. Additionally, and separately, replicas were connected to a mechanical lung simulator to simulate tidal breathing while undergoing high flow nasal cannula therapy, with tracheal pressure-time waveforms recorded. FINDINGS Faster gas clearance corresponded with higher flow rates (P<0.001), and with smaller cannula outlet area (P<0.001). Observed pressures were in approximate agreement with limited available in-vivo data in the literature. Between 0 and 60L/min cannula flow rates, tracheal positive end expiratory pressures increase was greater with the smallest cannula (∆PPEEP=785SD(185) Pa) compared to the largest cannula (∆PPEEP=380SD(120)Pa). Regression analysis indicates that positive end expiratory pressure is proportional to the square of flow velocities exiting the cannula and nares (R2=0.906). INTERPRETATION Since increased pressure and clearance rate have been associated with improved clinical outcomes in previous studies, our results suggest that smaller cannula outlet area may be preferable.
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Affiliation(s)
- Charles P Moore
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Ira M Katz
- Medical Research & Development, Air Liquide Santé Internationale, Centre de Recherche Paris-Saclay, France; Department of Mechanical Engineering, Lafayette College, Easton, PA, United States.
| | - Georges Caillibotte
- Medical Research & Development, Air Liquide Santé Internationale, Centre de Recherche Paris-Saclay, France.
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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Moore CP, Katz IM, Pichelin M, Caillibotte G, Finlay WH, Martin AR. High flow nasal cannula: Influence of gas type and flow rate on airway pressure and CO 2 clearance in adult nasal airway replicas. Clin Biomech (Bristol, Avon) 2019; 65:73-80. [PMID: 30991233 DOI: 10.1016/j.clinbiomech.2019.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 04/01/2019] [Accepted: 04/04/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND High flow nasal cannula therapy is a form of respiratory support which delivers high flow rates of heated, humidified gas to the nares via specialized cannula. Two primary mechanisms of action attributed to the therapy are the provision of positive airway pressure as well as clearance of CO2-rich exhaled gas from the upper airways. METHODS Physiologically accurate nose-throat airway replicas were connected at the trachea to a lung simulator, where CO2 was supplied to mimic the CO2 content in exhaled gas. Cannula delivered either air, oxygen or heliox (80/20%volume helium/oxygen) to the replicas at flow rates ranging from 0 to 60 l/min. Five replicas and three cannulas were compared. Tracheal pressure and CO2 concentration were continuously measured. The lung simulator provided breaths with tidal volume of 500 ml and frequency of 18 breaths/min. Additional clearance measurements were conducted for tidal volume and breathing frequency of 750 ml and 27 breaths/min, respectively. FINDINGS Cannula flow rate was the dominant factor governing CO2 concentration. Average CO2 concentration decreased with increasing cannula flow rate, but above 30 L/min this effect was less pronounced. Tracheal positive end-expiratory pressure increased with flow rate and was lower for heliox than for air or oxygen. A predictive correlation was developed and used to predict positive end-expiratory pressure for a given cannula size as a function of supplied flow rate and occlusion of the nares. INTERPRETATION Compared with administration of air or oxygen, administration of heliox is expected to result in similar CO2 clearance from the upper airway, but markedly lower airway pressure.
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Affiliation(s)
- C P Moore
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - I M Katz
- Air Liquide Santé International, Paris Innovation Campus, Les Loges en Josas, France.
| | - M Pichelin
- Air Liquide Santé International, Paris Innovation Campus, Les Loges en Josas, France.
| | - G Caillibotte
- Air Liquide Santé International, Paris Innovation Campus, Les Loges en Josas, France.
| | - W H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
| | - A R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
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Ly A, Carrigy NB, Wang H, Harrison M, Sauvageau D, Martin AR, Vehring R, Finlay WH. Atmospheric Spray Freeze Drying of Sugar Solution With Phage D29. Front Microbiol 2019; 10:488. [PMID: 30949139 PMCID: PMC6436606 DOI: 10.3389/fmicb.2019.00488] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/25/2019] [Indexed: 01/11/2023] Open
Abstract
Therapeutic bacteriophages offer a potential alternative approach in the treatment of drug resistant bacteria. In the present study, we examine the ability of atmospheric spray freeze-drying (ASFD) to process bacteriophage D29 into a solid dry formulation. Bacteriophage D29 is of particular interest due to its ability to infect Mycobacterium tuberculosis. A sugar solution containing bacteriophage D29 was sprayed and instantly frozen in a cold chamber. Cold drying gas was then passed through the chamber at a high flow rate and atmospheric pressure. Convective transport combined with the low temperature of the drying gas results in sublimation of ice, yielding a free-flowing, porous powder. The bacteriophages were atmospheric spray freeze-dried in solutions with varying concentrations of trehalose and mannitol. A solution of trehalose and mannitol at a mass ratio of 7:3 and a total mass concentration of 100 mg/mL led to powder with 4.9 ± 0.1% moisture content and an acceptable titer reduction of ∼0.6 logs. In comparison, a pure trehalose solution and a 1:1 ratio of trehalose and mannitol both had titer reductions of >1.5 logs. Spectroscopic analysis showed that trehalose in the powder was amorphous while mannitol completely crystallized during the drying process, both of which are desirable for preserving phage viability and storage in powders. The results highlight the potential for using ASFD as an alternative process in preserving biopharmaceutical products.
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Affiliation(s)
- Alvin Ly
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | | | - Hui Wang
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Melissa Harrison
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Dominic Sauvageau
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Andrew R Martin
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Reinhard Vehring
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
| | - Warren H Finlay
- Department of Engineering, University of Alberta, Edmonton, AB, Canada
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Kiaee M, Wachtel H, Noga ML, Martin AR, Finlay WH. An idealized geometry that mimics average nasal spray deposition in adults: A computational study. Comput Biol Med 2019; 107:206-217. [PMID: 30851506 DOI: 10.1016/j.compbiomed.2019.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/05/2019] [Accepted: 02/18/2019] [Indexed: 11/30/2022]
Abstract
This work describes the development of an idealized geometry that mimics average regional deposition of nasal sprays within realistic adult nasal geometries. Previous simulation results in seven realistic nasal airways (Kiaee et al. Int. J. Num. Methods Biomed. Eng. 34: e2968, 2018) were used to establish target values of regional deposition. Characteristic geometric features observed to be common to all the realistic nasal airway geometries studied were extracted and included in the idealized geometry. Additional geometric features and size scaling were explored, in order to enhance deposition in specific regions based on the results of simulations done in preliminary versions of the idealized geometry. In total, more than one hundred thousand simulation cases were conducted across a range of particle parameters and geometric shapes in order to reach the final idealized geometry presented herein. For droplet velocities of 0-20 m/s, droplet sizes of 5-40 μm and at an inhalation flow rate of 15 l/min, regional deposition in the final idealized geometry compares favourably with average deposition in each of the vestibule, valve, olfactory, turbinate, nasopharynx, and outlet regions in the realistic geometries. The proposed idealized nasal geometry has potential for use in the development and testing of nasal drug delivery systems, allowing researchers to estimate in vivo regional nasal deposition patterns using a simple benchtop test apparatus.
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Affiliation(s)
- Milad Kiaee
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | | | - Michelle L Noga
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada.
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Chen JZ, Katz IM, Pichelin M, Zhu K, Caillibotte G, Finlay WH, Martin AR. In Vitro–In Silico Comparison of Pulsed Oxygen Delivery From Portable Oxygen Concentrators Versus Continuous Flow Oxygen Delivery. Respir Care 2019; 64:117-129. [DOI: 10.4187/respcare.06359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
INTRODUCTION Aerosol drug delivery to the lungs via inhalation is widely used in the treatment of respiratory diseases. The deposition pattern of inhaled particles within the airways of the respiratory tract is key in determining the initial delivered dose. Thereafter, dose-dependent processes including drug release or dissolution, clearance, and absorption influence local and systemic exposure to inhaled drugs over time. AREAS COVERED Empirical correlations, numerical simulation, and in vitro airway geometries that permit improved prediction of extrathoracic and lung deposition fractions in a variety of age groups and breathing conditions are described. Efforts to link deposition models with pharmacokinetic models predicting lung and systemic exposure to inhaled drugs over time are then reviewed. Finally, new methods to predict intersubject variability in extrathoracic deposition, capturing variability in both size and shape of the upper airways, are highlighted. EXPERT OPINION Recent work has been done to expand in vitro deposition experiments to a wide range of age groups and breathing conditions, to link regional lung deposition models with pharmacokinetic models, and to improve prediction of intersubject variability. These efforts are improving predictive understanding of respiratory drug delivery, and will aid the development of new inhaled drugs and delivery devices.
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Affiliation(s)
- Andrew R Martin
- a Department of Mechanical Engineering , University of Alberta , Edmonton , AB , Canada
| | - Charles P Moore
- a Department of Mechanical Engineering , University of Alberta , Edmonton , AB , Canada
| | - Warren H Finlay
- a Department of Mechanical Engineering , University of Alberta , Edmonton , AB , Canada
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Paxman T, Noga M, Finlay WH, Martin AR. Experimental evaluation of pressure drop for flows of air and heliox through upper and central conducting airway replicas of 4- to 8-year-old children. J Biomech 2018; 82:134-141. [PMID: 30522876 DOI: 10.1016/j.jbiomech.2018.10.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 11/15/2022]
Abstract
Airway resistance describes the ratio between pressure drop and flow rate through the conducting respiratory airways. Analytical models of airway resistance for tracheobronchial airways have previously been developed and assessed without upper airways positioned upstream of the trachea. This work investigated pressure drop as a function of flow rate and gas properties for upper and central airway replicas of 10 child subjects, ages 4-8. Replica geometries were built based on computed tomography scan data and included airways from the nose through 3-5 distal branching airway generations. Pressure drop through the replicas was measured for constant inspiratory flows of air and heliox. For both the nose-throat and branching airways, the relationship between non-dimensional coefficient of friction, CF, with Reynolds number, Re, was found to resemble the turbulent Blasius equation for pipe flow, where CF∝Re-0.25. Additionally, pressure drop ratios between heliox and air were consistent with analytical predictions for turbulent flow. The presence of turbulence in the branching airways likely resulted from convection of turbulence produced upstream in the nose and throat. An airway resistance model based on the Blasius pipe friction correlation for turbulent flow was proposed for prediction of pressure drop through the branching bronchial airways downstream from the upper airway.
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Affiliation(s)
- Tyler Paxman
- Department of Mechanical Engineering, University of Alberta, Canada.
| | - Michelle Noga
- Department of Radiology & Diagnostic Imaging, University of Alberta, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Canada.
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Ruzycki CA, Martin AR, Vehring R, Finlay WH. AnIn VitroExamination of the Effects of Altitude on Dry Powder Inhaler Performance. J Aerosol Med Pulm Drug Deliv 2018; 31:221-236. [DOI: 10.1089/jamp.2017.1417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Conor A. Ruzycki
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R. Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Reinhard Vehring
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Warren H. Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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Kiaee M, Wachtel H, Noga ML, Martin AR, Finlay WH. Regional deposition of nasal sprays in adults: A wide ranging computational study. Int J Numer Method Biomed Eng 2018; 34:e2968. [PMID: 29453801 DOI: 10.1002/cnm.2968] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 02/02/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
The present work examines regional deposition within the nose for nasal sprays over a large and wide ranging parameter space by using numerical simulation. A set of 7 realistic adult nasal airway geometries was defined based on computed tomography images. Deposition in 6 regions of each nasal airway geometry (the vestibule, valve, anterior turbinate, posterior turbinate, olfactory, and nasopharynx) was determined for varying particle diameter, spray cone angle, spray release direction, particle injection speed, and particle injection location. Penetration of nasal spray particles through the airway geometries represented unintended lung exposure. Penetration was found to be relatively insensitive to injection velocity, but highly sensitive to particle size. Penetration remained at or above 30% for particles exceeding 10 μm in diameter for several airway geometries studied. Deposition in the turbinates, viewed as desirable for both local and systemic nasal drug delivery, was on average maximized for particles ranging from ~20 to 30 μm in diameter, and for low to zero injection velocity. Similar values of particle diameter and injection velocity were found to maximize deposition in the olfactory region, a potential target for nose-to-brain drug delivery. However, olfactory deposition was highly variable between airway geometries, with maximum olfactory deposition ranging over 2 orders of magnitude between geometries. This variability is an obstacle to overcome if consistent dosing between subjects is to be achieved for nose-to-brain drug delivery.
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Affiliation(s)
- Milad Kiaee
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | | | - Michelle L Noga
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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Duncan LE, Ratanatharathorn A, Aiello AE, Almli LM, Amstadter AB, Ashley-Koch AE, Baker DG, Beckham JC, Bierut LJ, Bisson J, Bradley B, Chen CY, Dalvie S, Farrer LA, Galea S, Garrett ME, Gelernter JE, Guffanti G, Hauser MA, Johnson EO, Kessler RC, Kimbrel NA, King A, Koen N, Kranzler HR, Logue MW, Maihofer AX, Martin AR, Miller MW, Morey RA, Nugent NR, Rice JP, Ripke S, Roberts AL, Saccone NL, Smoller JW, Stein DJ, Stein MB, Sumner JA, Uddin M, Ursano RJ, Wildman DE, Yehuda R, Zhao H, Daly MJ, Liberzon I, Ressler KJ, Nievergelt CM, Koenen KC. Largest GWAS of PTSD (N=20 070) yields genetic overlap with schizophrenia and sex differences in heritability. Mol Psychiatry 2018; 23:666-673. [PMID: 28439101 PMCID: PMC5696105 DOI: 10.1038/mp.2017.77] [Citation(s) in RCA: 275] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 01/19/2017] [Accepted: 02/15/2017] [Indexed: 12/12/2022]
Abstract
The Psychiatric Genomics Consortium-Posttraumatic Stress Disorder group (PGC-PTSD) combined genome-wide case-control molecular genetic data across 11 multiethnic studies to quantify PTSD heritability, to examine potential shared genetic risk with schizophrenia, bipolar disorder, and major depressive disorder and to identify risk loci for PTSD. Examining 20 730 individuals, we report a molecular genetics-based heritability estimate (h2SNP) for European-American females of 29% that is similar to h2SNP for schizophrenia and is substantially higher than h2SNP in European-American males (estimate not distinguishable from zero). We found strong evidence of overlapping genetic risk between PTSD and schizophrenia along with more modest evidence of overlap with bipolar and major depressive disorder. No single-nucleotide polymorphisms (SNPs) exceeded genome-wide significance in the transethnic (overall) meta-analysis and we do not replicate previously reported associations. Still, SNP-level summary statistics made available here afford the best-available molecular genetic index of PTSD-for both European- and African-American individuals-and can be used in polygenic risk prediction and genetic correlation studies of diverse phenotypes. Publication of summary statistics for ∼10 000 African Americans contributes to the broader goal of increased ancestral diversity in genomic data resources. In sum, the results demonstrate genetic influences on the development of PTSD, identify shared genetic risk between PTSD and other psychiatric disorders and highlight the importance of multiethnic/racial samples. As has been the case with schizophrenia and other complex genetic disorders, larger sample sizes are needed to identify specific risk loci.
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Affiliation(s)
- L E Duncan
- Department of Psychiatry, Stanford University, Stanford, CA, USA
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- The Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | | | - A E Aiello
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, Chapel Hill, NC, USA
| | - L M Almli
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - A B Amstadter
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
| | - A E Ashley-Koch
- Department of Medicine, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - D G Baker
- Veterans Affairs San Diego Healthcare System and Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - J C Beckham
- Veterans Affairs Durham Healthcare System, Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - L J Bierut
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - J Bisson
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - B Bradley
- Atlanta VA Medical Center, Atlanta, GA, USA
- Department of Psychiatry, Emory University, Atlanta, GA, USA
| | - C-Y Chen
- The Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Department of Psychiatry, Harvard University, Cambridge, MA, USA
| | - S Dalvie
- Division of Human Genetics, University of Cape Town, Cape Town, South Africa
| | - L A Farrer
- Biomedical Genetics, Boston University School of Medicine, Boston, MA, USA
| | - S Galea
- Boston University School of Public Health, Boston, MA, USA
| | - M E Garrett
- Department of Medicine, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - J E Gelernter
- Department of Psychiatry, Yale University School of Medicine and VA CT Healthcare System, New Haven, CT, USA
| | - G Guffanti
- Department of Psychiatry, Harvard University, Cambridge, MA, USA
- Department of Psychiatry, McLean Hospital, Belmont, MA, USA
| | - M A Hauser
- Department of Medicine, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - E O Johnson
- RTI International, Research Triangle Park, NC, USA
| | - R C Kessler
- Department of Health Care Policy, Harvard Medical School, Boston, MA, USA
| | - N A Kimbrel
- Veterans Affairs Durham Healthcare System, Durham, NC, USA
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - A King
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - N Koen
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- MRC Unit on Anxiety & Stress Disorders, Groote Schuur Hospital, Cape Town, South Africa
| | - H R Kranzler
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine and VISN 4 MIRECC, Crescenz VAMC, Philadelphia, PA, USA
| | - M W Logue
- VA Boston Healthcare System, Jamaica Plain, MA, USA
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - A X Maihofer
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - A R Martin
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- The Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - M W Miller
- VA Boston Healthcare System, Jamaica Plain, MA, USA
- Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
| | - R A Morey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
- Durham VA Medical Center, Durham, NC, USA
| | - N R Nugent
- Division of Behavioral Genetics, Department of Psychiatry, Rhode Island Hospital, Providence, RI, USA
- Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, RI, USA
| | - J P Rice
- Department of Psychiatry, Washington University, St Louis, MO, USA
| | - S Ripke
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- The Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Department of Psychiatry and Psychotherapy, Charité, Campus Mitte, Berlin, Germany
| | - A L Roberts
- Department of Social and Behavioral Sciences, Harvard T. H. Chan School of Public Health Cambridge, MA, USA
| | - N L Saccone
- Department of Genetics, Washington University, St Louis, MO, USA
| | - J W Smoller
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - D J Stein
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- MRC Unit on Anxiety & Stress Disorders, Groote Schuur Hospital, Cape Town, South Africa
| | - M B Stein
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - J A Sumner
- Center for Cardiovascular Behavioral Health, Columbia University Medical Center, New York, NY, USA
| | - M Uddin
- Department of Psychology and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - R J Ursano
- Center for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - D E Wildman
- Department of Molecular & Integrative Physiology and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - R Yehuda
- James J. Peters Bronx Veterans Affairs and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, Bronx, NY, USA
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Bronx, NY, USA
| | - H Zhao
- Department of Biostatistics, Yale University, New Haven, CT, USA
| | - M J Daly
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- The Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - I Liberzon
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Health System, Ann Arbor, MI, USA
| | - K J Ressler
- Department of Psychiatry, Harvard University, Cambridge, MA, USA
- Department of Psychiatry, McLean Hospital, Belmont, MA, USA
| | - C M Nievergelt
- Veterans Affairs San Diego Healthcare System and Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - K C Koenen
- Broad Institute of MIT and Harvard, Stanley Center for Psychiatric Research, Boston, MA, USA
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Department of Epidemiology, Harvard T. H. Chan School of Public Health, Cambridge, MA, USA
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Martin AR, Da Silva VMF. Reproductive parameters of the Amazon river dolphin or boto, Inia geoffrensis (Cetacea: Iniidae); an evolutionary outlier bucks no trends. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- A R Martin
- Centre for Remote Environments, University of Dundee, Nethergate, Dundee, UK
| | - V M F Da Silva
- Instituto Nacional de Pesquisas da Amazônia, Petrópolis, Manaus/AM, Brazil
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Zapol WM, Charles HC, Martin AR, Sá RC, Yu B, Ichinose F, MacIntyre N, Mammarappallil J, Moon R, Chen JZ, Geier ET, Darquenne C, Prisk GK, Katz I. Pulmonary Delivery of Therapeutic and Diagnostic Gases. J Aerosol Med Pulm Drug Deliv 2018; 31:78-87. [PMID: 29451844 DOI: 10.1089/jamp.2017.1431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The 21st Congress for the International Society for Aerosols in Medicine included, for the first time, a session on Pulmonary Delivery of Therapeutic and Diagnostic Gases. The rationale for such a session within ISAM is that the pulmonary delivery of gaseous drugs in many cases targets the same therapeutic areas as aerosol drug delivery, and is in many scientific and technical aspects similar to aerosol drug delivery. This article serves as a report on the recent ISAM congress session providing a synopsis of each of the presentations. The topics covered are the conception, testing, and development of the use of nitric oxide to treat pulmonary hypertension; the use of realistic adult nasal replicas to evaluate the performance of pulsed oxygen delivery devices; an overview of several diagnostic gas modalities; and the use of inhaled oxygen as a proton magnetic resonance imaging (MRI) contrast agent for imaging temporal changes in the distribution of specific ventilation during recovery from bronchoconstriction. Themes common to these diverse applications of inhaled gases in medicine are discussed, along with future perspectives on development of therapeutic and diagnostic gases.
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Affiliation(s)
- Warren M Zapol
- 1 Anesthesia Center for Critical Care Research , Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - H Cecil Charles
- 2 Duke Image Analysis Laboratory, Center for Advanced MR Development, Department of Radiology, Duke University School of Medicine , Durham, North Carolina
| | - Andrew R Martin
- 3 Department of Mechanical Engineering, University of Alberta , Edmonton, Canada
| | - Rui C Sá
- 4 Department of Medicine, University of California , San Diego, San Diego, California
| | - Binglan Yu
- 1 Anesthesia Center for Critical Care Research , Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Fumito Ichinose
- 1 Anesthesia Center for Critical Care Research , Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Neil MacIntyre
- 5 Department of Pulmonology, Duke University School of Medicine , Durham, North Carolina
| | - Joseph Mammarappallil
- 6 Department of Radiology, Duke University School of Medicine , Durham, North Carolina
| | - Richard Moon
- 7 Department of Anesthesiology, Duke University School of Medicine , Durham, North Carolina
| | - John Z Chen
- 3 Department of Mechanical Engineering, University of Alberta , Edmonton, Canada
| | - Eric T Geier
- 4 Department of Medicine, University of California , San Diego, San Diego, California
| | - Chantal Darquenne
- 4 Department of Medicine, University of California , San Diego, San Diego, California
| | - G Kim Prisk
- 4 Department of Medicine, University of California , San Diego, San Diego, California.,8 Department of Radiology, University of California , San Diego, San Diego, California
| | - Ira Katz
- 9 Medical R&D, Air Liquide Santé International , Les Loges-en-Josas, France .,10 Department of Mechanical Engineering, Lafayette College , Easton, Pennsylvania
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Chen JZ, Katz IM, Pichelin M, Zhu K, Caillibotte G, Noga ML, Finlay WH, Martin AR. Comparison of pulsed versus continuous oxygen delivery using realistic adult nasal airway replicas. Int J Chron Obstruct Pulmon Dis 2017; 12:2559-2571. [PMID: 28883723 PMCID: PMC5574700 DOI: 10.2147/copd.s141976] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Portable oxygen concentrators (POCs) typically include pulse flow (PF) modes to conserve oxygen. The primary aims of this study were to develop a predictive in vitro model for inhaled oxygen delivery using a set of realistic airway replicas, and to compare PF for a commercial POC with steady flow (SF) from a compressed oxygen cylinder. METHODS Experiments were carried out using a stationary compressed oxygen cylinder, a POC, and 15 adult nasal airway replicas based on airway geometries derived from medical images. Oxygen delivery via nasal cannula was tested at PF settings of 2.0 and 6.0, and SF rates of 2.0 and 6.0 L/min. A test lung simulated three breathing patterns representative of a chronic obstructive pulmonary disease patient at rest, during exercise, and while asleep. Volume-averaged fraction of inhaled oxygen (FiO2) was calculated by analyzing oxygen concentrations sampled at the exit of each replica and inhalation flow rates over time. POC pulse volumes were also measured using a commercial O2 conserver test system to attempt to predict FiO2 for PF. RESULTS Relative volume-averaged FiO2 using PF ranged from 68% to 94% of SF values, increasing with breathing frequency and tidal volume. Three of 15 replicas failed to trigger the POC when used with the sleep breathing pattern at the 2.0 setting, and four of 15 replicas failed to trigger at the 6.0 setting. FiO2 values estimated from POC pulse characteristics followed similar trends but were lower than those derived from airway replica experiments. CONCLUSION For the POC tested, PF delivered similar, though consistently lower, volume-averaged FiO2 than SF rates equivalent to nominal PF settings. Assessment of PF oxygen delivery using POC pulse characteristics alone may be insufficient; testing using airway replicas is useful in identifying possible cases of failure and may provide a better assessment of FiO2.
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Affiliation(s)
- John Z Chen
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Ira M Katz
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas
| | - Marine Pichelin
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas
| | - Kaixian Zhu
- Centre Explor!, Air Liquide Healthcare, Gentilly, France
| | - Georges Caillibotte
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas
| | - Michelle L Noga
- Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
| | - Warren H Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
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Martin AR, Finlay WH. Model Calculations of Regional Deposition and Disposition for Single Doses of Inhaled Liposomal and Dry Powder Ciprofloxacin. J Aerosol Med Pulm Drug Deliv 2017; 31:49-60. [PMID: 28708440 DOI: 10.1089/jamp.2017.1377] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Model predictions of regional deposition in the respiratory tract are useful in assessing factors that influence the effectiveness of aerosol delivery. Regional deposition models have previously been coupled with models of mucous production and clearance to estimate initial concentrations of drug deposited in the airway surface liquid (ASL) lining tracheobronchial airways. METHODS Established models of regional deposition and ASL volumes were used to provide input to a new model evaluating the disposition of drug resulting from dissolution or release, absorption, and mucociliary clearance. Additional modeling of oral absorption, distribution, and elimination allowed prediction of systemic exposure. Herein, predicted ASL and plasma concentrations of free (dissolved or unencapsulated) ciprofloxacin over time are reported for a healthy, adult lung model following inhalation of single doses of nebulized liposomal (6 mL of liposomal ciprofloxacin for inhalation, 50 mg/mL, or 6 mL of Pulmaquin, 210 mg; Aradigm) and dry powder (32.5 and 65 mg doses; Bayer) formulations. RESULTS Over a range of mucous production rates and tracheal clearance velocities, peak ASL concentrations of free ciprofloxacin were consistently greater for Pulmaquin than for other formulations investigated, owing to the presence of free drug in the nebulized Pulmaquin formulation. The time that ASL concentrations of free drug remained above the minimum inhibitory concentration for Pseudomonas aeruginosa was similar for all four formulations. Predicted plasma ciprofloxacin concentration profiles were in good agreement with available data from Phase I trials in healthy volunteers. CONCLUSIONS Predictions of ASL drug concentrations over time are valuable in elucidating the roles of deposition, drug release or dissolution, and disposition on the effectiveness of inhaled aerosol therapies. For inhaled ciprofloxacin, the present results predict similar ASL concentrations of free drug over time following single doses of inhaled liposomal and dry powder formulations. The impact of multiple doses and airway disease warrants further consideration.
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Affiliation(s)
- Andrew R Martin
- Mechanical Engineering, University of Alberta , Alberta, Canada
| | - Warren H Finlay
- Mechanical Engineering, University of Alberta , Alberta, Canada
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Litwin PD, Reis Dib AL, Chen J, Noga M, Finlay WH, Martin AR. Theoretical and experimental evaluation of the effects of an argon gas mixture on the pressure drop through adult tracheobronchial airway replicas. J Biomech 2017; 58:217-221. [DOI: 10.1016/j.jbiomech.2017.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/04/2017] [Accepted: 04/09/2017] [Indexed: 11/27/2022]
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Martin AR, De Leener B, Cohen-Adad J, Cadotte DW, Kalsi-Ryan S, Lange SF, Tetreault L, Nouri A, Crawley A, Mikulis DJ, Ginsberg H, Fehlings MG. Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability. AJNR Am J Neuroradiol 2017; 38:1257-1265. [PMID: 28428213 DOI: 10.3174/ajnr.a5163] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/28/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE DTI, magnetization transfer, T2*-weighted imaging, and cross-sectional area can quantify aspects of spinal cord microstructure. However, clinical adoption remains elusive due to complex acquisitions, cumbersome analysis, limited reliability, and wide ranges of normal values. We propose a simple multiparametric protocol with automated analysis and report normative data, analysis of confounding variables, and reliability. MATERIALS AND METHODS Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences. Cross-sectional area, fractional anisotropy, magnetization transfer ratio, and T2*WI WM/GM signal intensity ratio were calculated. Relationships between MR imaging metrics and age, sex, height, weight, cervical cord length, and rostrocaudal level were analyzed. Test-retest coefficient of variation measured reliability in 24 DTI, 17 magnetization transfer, and 16 T2*WI datasets. DTI with and without cardiac triggering was compared in 10 subjects. RESULTS T2*WI WM/GM showed lower intersubject coefficient of variation (3.5%) compared with magnetization transfer ratio (5.8%), fractional anisotropy (6.0%), and cross-sectional area (12.2%). Linear correction of cross-sectional area with cervical cord length, fractional anisotropy with age, and magnetization transfer ratio with age and height led to decreased coefficients of variation (4.8%, 5.4%, and 10.2%, respectively). Acceptable reliability was achieved for all metrics/levels (test-retest coefficient of variation < 5%), with T2*WI WM/GM comparing favorably with fractional anisotropy and magnetization transfer ratio. DTI with and without cardiac triggering showed no significant differences for fractional anisotropy and test-retest coefficient of variation. CONCLUSIONS Reliable multiparametric assessment of spinal cord microstructure is possible by using clinically suitable methods. These results establish normalization procedures and pave the way for clinical studies, with the potential for improving diagnostics, objectively monitoring disease progression, and predicting outcomes in spinal pathologies.
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Affiliation(s)
- A R Martin
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - B De Leener
- Polytechnique Montreal (B.D.L., J.C.-A.), Montréal, Quebec, Canada
| | - J Cohen-Adad
- Polytechnique Montreal (B.D.L., J.C.-A.), Montréal, Quebec, Canada
- Functional Neuroimaging Unit (J.C.-A.), Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Université de Montréal, Montréal, Quebec, Canada
| | - D W Cadotte
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S Kalsi-Ryan
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S F Lange
- University of Groningen (S.F.L.), Groningen, the Netherlands
| | - L Tetreault
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Nouri
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Crawley
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - D J Mikulis
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - H Ginsberg
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - M G Fehlings
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
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Martin AR, De Leener B, Cohen-Adad J, Cadotte DW, Kalsi-Ryan S, Lange SF, Tetreault L, Nouri A, Crawley A, Mikulis DJ, Ginsberg H, Fehlings MG. A Novel MRI Biomarker of Spinal Cord White Matter Injury: T2*-Weighted White Matter to Gray Matter Signal Intensity Ratio. AJNR Am J Neuroradiol 2017; 38:1266-1273. [PMID: 28428212 DOI: 10.3174/ajnr.a5162] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/29/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE T2*-weighted imaging provides sharp contrast between spinal cord GM and WM, allowing their segmentation and cross-sectional area measurement. Injured WM demonstrates T2*WI hyperintensity but requires normalization for quantitative use. We introduce T2*WI WM/GM signal-intensity ratio and compare it against cross-sectional area, the DTI metric fractional anisotropy, and magnetization transfer ratio in degenerative cervical myelopathy. MATERIALS AND METHODS Fifty-eight patients with degenerative cervical myelopathy and 40 healthy subjects underwent 3T MR imaging, covering C1-C7. Metrics were automatically extracted at maximally compressed and uncompressed rostral/caudal levels. Normalized metrics were compared with t tests, area under the curve, and logistic regression. Relationships with clinical measures were analyzed by using Pearson correlation and multiple linear regression. RESULTS The maximally compressed level cross-sectional area demonstrated superior differences (P = 1 × 10-13), diagnostic accuracy (area under the curve = 0.890), and univariate correlation with the modified Japanese Orthopedic Association score (0.66). T2*WI WM/GM showed strong differences (rostral: P = 8 × 10-7; maximally compressed level: P = 1 × 10-11; caudal: P = 1 × 10-4), correlations (modified Japanese Orthopedic Association score; rostral: -0.52; maximally compressed level: -0.59; caudal: -0.36), and diagnostic accuracy (rostral: 0.775; maximally compressed level: 0.860; caudal: 0.721), outperforming fractional anisotropy and magnetization transfer ratio in most comparisons and cross-sectional area at rostral/caudal levels. Rostral T2*WI WM/GM showed the strongest correlations with focal motor (-0.45) and sensory (-0.49) deficits and was the strongest independent predictor of the modified Japanese Orthopedic Association score (P = .01) and diagnosis (P = .02) in multivariate models (R2 = 0.59, P = 8 × 10-13; area under the curve = 0.954, respectively). CONCLUSIONS T2*WI WM/GM shows promise as a novel biomarker of WM injury. It detects damage in compressed and uncompressed regions and contributes substantially to multivariate models for diagnosis and correlation with impairment. Our multiparametric approach overcomes limitations of individual measures, having the potential to improve diagnostics, monitor progression, and predict outcomes.
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Affiliation(s)
- A R Martin
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - B De Leener
- Polytechnique Montreal (B.D.L., J.C.-A.), Montreal, Quebec, Canada
| | - J Cohen-Adad
- Polytechnique Montreal (B.D.L., J.C.-A.), Montreal, Quebec, Canada.,Functional Neuroimaging Unit (J.C.-A.), Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Université de Montréal, Montreal, Quebec, Canada
| | - D W Cadotte
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S Kalsi-Ryan
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S F Lange
- University of Groningen (S.F.L.), Groningen, the Netherlands
| | - L Tetreault
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Nouri
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Crawley
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto, Ontario, Canada
| | - D J Mikulis
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto, Ontario, Canada
| | - H Ginsberg
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - M G Fehlings
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
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Woldemariam DM, Kullab A, Martin AR. District Heat-Driven Water Purification via Membrane Distillation: New Possibilities for Applications in Pharmaceutical Industries. Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.6b04740] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daniel M. Woldemariam
- Energy Technology Department, KTH Royal Institute of Technology, Brinellvägen 68, 10044 Stockholm, Sweden
| | - Alaa Kullab
- Energy Technology Department, KTH Royal Institute of Technology, Brinellvägen 68, 10044 Stockholm, Sweden
| | - Andrew R. Martin
- Energy Technology Department, KTH Royal Institute of Technology, Brinellvägen 68, 10044 Stockholm, Sweden
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Wee WB, Tavernini S, Martin AR, Amirav I, Majaesic C, Finlay WH. Dry Powder Inhaler Delivery of Tobramycin in In Vitro Models of Tracheostomized Children. J Aerosol Med Pulm Drug Deliv 2017; 30:64-70. [DOI: 10.1089/jamp.2016.1309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Wallace B. Wee
- Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Scott Tavernini
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Andrew R. Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Israel Amirav
- Department of Pediatric Pulmonology, University of Alberta, Edmonton, Canada
| | - Carina Majaesic
- Department of Pediatric Pulmonology, University of Alberta, Edmonton, Canada
| | - Warren H. Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
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Abstract
New gas therapies using inert gases such as xenon and argon are being studied, which require in vitro and in vivo preclinical experiments. Examples of the kinetics of gas transport during such experiments are analyzed in this paper. Using analytical and numerical models, we analyze an in vitro experiment for gas transport to a 96 cell well plate and an in vivo delivery to a small animal chamber, where the key processes considered are the wash-in of test gas into an apparatus dead volume, the diffusion of test gas through the liquid media in a well of a cell test plate, and the pharmacokinetics in a rat. In the case of small animals in a chamber, the key variable controlling the kinetics is the chamber wash-in time constant that is a function of the chamber volume and the gas flow rate. For cells covered by a liquid media the diffusion of gas through the liquid media is the dominant mechanism, such that liquid depth and the gas diffusion constant are the key parameters. The key message from these analyses is that the transport of gas during preclinical experiments can be important in determining the true dose as experienced at the site of action in an animal or to a cell.
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Affiliation(s)
- Ira Katz
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 78354, Jouy-en-Josas, France; Department of Mechanical Engineering, Lafayette College, Easton, PA, USA
| | - Marc Palgen
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 78354, Jouy-en-Josas, France
| | - Jacqueline Murdock
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 78354, Jouy-en-Josas, France
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton AB T6G 2G8, Canada
| | - Géraldine Farjot
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 78354, Jouy-en-Josas, France
| | - Georges Caillibotte
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 78354, Jouy-en-Josas, France
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Katz I, Pichelin M, Montesantos S, Kang MY, Sapoval B, Zhu K, Thevenin CP, McCoy R, Martin AR, Caillibotte G. An in silico analysis of oxygen uptake of a mild COPD patient during rest and exercise using a portable oxygen concentrator. Int J Chron Obstruct Pulmon Dis 2016; 11:2427-2434. [PMID: 27729783 PMCID: PMC5047718 DOI: 10.2147/copd.s112473] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Oxygen treatment based on intermittent-flow devices with pulse delivery modes available from portable oxygen concentrators (POCs) depends on the characteristics of the delivered pulse such as volume, pulse width (the time of the pulse to be delivered), and pulse delay (the time for the pulse to be initiated from the start of inhalation) as well as a patient's breathing characteristics, disease state, and respiratory morphology. This article presents a physiological-based analysis of the performance, in terms of blood oxygenation, of a commercial POC at different settings using an in silico model of a COPD patient at rest and during exercise. The analysis encompasses experimental measurements of pulse volume, width, and time delay of the POC at three different settings and two breathing rates related to rest and exercise. These experimental data of device performance are inputs to a physiological-based model of oxygen uptake that takes into account the real dynamic nature of gas exchange to illustrate how device- and patient-specific factors can affect patient oxygenation. This type of physiological analysis that considers the true effectiveness of oxygen transfer to the blood, as opposed to delivery to the nose (or mouth), can be instructive in applying therapies and designing new devices.
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Affiliation(s)
- Ira Katz
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France; Department of Mechanical Engineering, Lafayette College, Easton, PA, USA
| | - Marine Pichelin
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France
| | - Spyridon Montesantos
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France
| | - Min-Yeong Kang
- Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau
| | - Bernard Sapoval
- Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau; Centre de Mathématiques et de leurs Applications, CNRS, UniverSud, Cachan
| | - Kaixian Zhu
- Centre Explor!, Air Liquide Healthcare, Gentilly, France
| | | | - Robert McCoy
- Valley Inspired Products, Inc, Apple Valley, MN, USA
| | - Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Georges Caillibotte
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France
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Martin AR, Jackson C, Fromont S, Pont C, Katz IM, Caillobotte G. An injection and mixing element for delivery and monitoring of inhaled nitric oxide. Biomed Eng Online 2016; 15:103. [PMID: 27576350 PMCID: PMC5004310 DOI: 10.1186/s12938-016-0227-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/19/2016] [Indexed: 11/10/2022] Open
Abstract
Background Inhaled nitric oxide (NO) is a selective pulmonary vasodilator used primarily in the critical care setting for patients concurrently supported by invasive or noninvasive positive pressure ventilation. NO delivery devices interface with ventilator breathing circuits to inject NO in proportion with the flow of air/oxygen through the circuit, in order to maintain a constant, target concentration of inhaled NO. Methods In the present article, a NO injection and mixing element is presented. The device borrows from the design of static elements to promote rapid mixing of injected NO-containing gas with breathing circuit gases. Bench experiments are reported to demonstrate the improved mixing afforded by the injection and mixing element, as compared with conventional breathing circuit adapters, for NO injection into breathing circuits. Computational fluid dynamics simulations are also presented to illustrate mixing patterns and nitrogen dioxide production within the element. Results Over the range of air flow rates and target NO concentrations investigated, mixing length, defined as the downstream distance required for NO concentration to reach within ±5 % of the target concentration, was as high as 47 cm for the conventional breathing circuit adapters, but did not exceed 7.8 cm for the injection and mixing element. Conclusion The injection and mixing element has potential to improve ease of use, compatibility and safety of inhaled NO administration with mechanical ventilators and gas delivery devices.
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Affiliation(s)
- Andrew R Martin
- Department of Mechanical Engineering, University of Alberta, 10-324 Donadeo Innovation Centre for Engineering, Edmonton, AB T6G 1H9, Canada.
| | - Chris Jackson
- Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Samuel Fromont
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 1 Chemin de la Porte des Loges, B.P. 126, 78354, Les Loges-en-Josas, France
| | - Chloe Pont
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 1 Chemin de la Porte des Loges, B.P. 126, 78354, Les Loges-en-Josas, France
| | - Ira M Katz
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 1 Chemin de la Porte des Loges, B.P. 126, 78354, Les Loges-en-Josas, France.,Department of Mechanical Engineering, Lafayette College, Easton, PA, 18042, USA
| | - Georges Caillobotte
- Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, 1 Chemin de la Porte des Loges, B.P. 126, 78354, Les Loges-en-Josas, France
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Darquenne C, Fleming JS, Katz I, Martin AR, Schroeter J, Usmani OS, Venegas J, Schmid O. Bridging the Gap Between Science and Clinical Efficacy: Physiology, Imaging, and Modeling of Aerosols in the Lung. J Aerosol Med Pulm Drug Deliv 2016; 29:107-26. [PMID: 26829187 DOI: 10.1089/jamp.2015.1270] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Development of a new drug for the treatment of lung disease is a complex and time consuming process involving numerous disciplines of basic and applied sciences. During the 2015 Congress of the International Society for Aerosols in Medicine, a group of experts including aerosol scientists, physiologists, modelers, imagers, and clinicians participated in a workshop aiming at bridging the gap between basic research and clinical efficacy of inhaled drugs. This publication summarizes the current consensus on the topic. It begins with a short description of basic concepts of aerosol transport and a discussion on targeting strategies of inhaled aerosols to the lungs. It is followed by a description of both computational and biological lung models, and the use of imaging techniques to determine aerosol deposition distribution (ADD) in the lung. Finally, the importance of ADD to clinical efficacy is discussed. Several gaps were identified between basic science and clinical efficacy. One gap between scientific research aimed at predicting, controlling, and measuring ADD and the clinical use of inhaled aerosols is the considerable challenge of obtaining, in a single study, accurate information describing the optimal lung regions to be targeted, the effectiveness of targeting determined from ADD, and some measure of the drug's effectiveness. Other identified gaps were the language and methodology barriers that exist among disciplines, along with the significant regulatory hurdles that need to be overcome for novel drugs and/or therapies to reach the marketplace and benefit the patient. Despite these gaps, much progress has been made in recent years to improve clinical efficacy of inhaled drugs. Also, the recent efforts by many funding agencies and industry to support multidisciplinary networks including basic science researchers, R&D scientists, and clinicians will go a long way to further reduce the gap between science and clinical efficacy.
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Affiliation(s)
- Chantal Darquenne
- 1 Department of Medicine, University of California , San Diego, La Jolla, California
| | - John S Fleming
- 2 National Institute of Health Research Biomedical Research Unit in Respiratory Disease , Southampton, United Kingdom .,3 Department of Medical Physics and Bioengineering, University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom
| | - Ira Katz
- 4 Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay , Jouy-en-Josas, France .,5 Department of Mechanical Engineering, Lafayette College , Easton, Pennsylvania
| | - Andrew R Martin
- 6 Department of Mechanical Engineering, University of Alberta , Edmonton, Alberta, Canada
| | | | - Omar S Usmani
- 8 Airway Disease Section, National Heart and Lung Institute , Imperial College London and Royal Brompton Hospital, London, United Kingdom
| | - Jose Venegas
- 9 Department of Anesthesia (Bioengineering), MGH/Harvard, Boston, Massachusetts
| | - Otmar Schmid
- 10 Comprehensive Pneumology Center (CPC), Member of the German Center for Lung Research , Munich, Germany .,11 Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health , Neuherberg, Germany
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