1
|
Kreiss L, Wu M, Wayne M, Xu S, McKee P, Dwamena D, Kim K, Lee KC, Cowdrick KR, Liu W, Ülkü A, Harfouche M, Yang X, Cook C, Lee SA, Buckley E, Bruschini C, Charbon E, Huettel S, Horstmeyer R. Beneath the surface: revealing deep-tissue blood flow in human subjects with massively parallelized diffuse correlation spectroscopy. NEUROPHOTONICS 2025; 12:025007. [PMID: 40206420 PMCID: PMC11981687 DOI: 10.1117/1.nph.12.2.025007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2024] [Revised: 03/07/2025] [Accepted: 03/11/2025] [Indexed: 04/11/2025]
Abstract
Significance Diffuse correlation spectroscopy (DCS) allows label-free, non-invasive investigation of microvascular dynamics deep within tissue, such as cerebral blood flow (CBF). However, the signal-to-noise ratio (SNR) in DCS limits its effective cerebral sensitivity in adults, in which the depth to the brain, through the scalp and skull, is substantially larger than in infants. Aim Therefore, we aim to increase its SNR and, ultimately, its sensitivity to CBF through new DCS techniques. Approach We present an in vivo demonstration of parallelized DCS (PDCS) to measure cerebral and muscular blood flow in healthy adults. Our setup employs an innovative array with hundreds of thousands single photon avalanche diodes (SPAD) in a 500 × 500 grid to boost SNR by averaging all independent pixel measurements. We tested this device on different total pixel counts and frame rates. A secondary, smaller array was used for reference measurements from shallower tissue at lower source-detector-separation (SDS). Results The new system can measure pulsatile blood flow in cerebral and muscular tissue, at up to 4 cm SDS, while maintaining a similar measurement noise as compared with a previously published 32 × 32 PDCS system at 1.5 cm SDS. Data from a cohort of 15 adults provide strong experimental evidence for functional CBF activity during a cognitive memory task and allowed analysis of pulse markers. Additional control experiments on muscular blood flow in the forearm with a different technical configuration provide converging evidence for the efficacy of this technique. Conclusions Our results outline successful PDCS measurements with large SPAD arrays to enable detect CBF in human adults. The ongoing development of SPAD camera technology is expected to result in larger and faster detectors in the future. In combination with new data processing techniques, tailored for the sparse signal of binary photon detection events in SPADs, this could lead to even greater SNR increase and ultimately greater depth sensitivity of PDCS.
Collapse
Affiliation(s)
- Lucas Kreiss
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Melissa Wu
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Michael Wayne
- École polytechnique fédérale de Lausanne (EPFL), Advanced Quantum Architecture Laboratory, Neuchatel, Switzerland
| | - Shiqi Xu
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Paul McKee
- Duke University, Department of Psychology and Neuroscience, Durham, North Carolina, United States
| | - Derrick Dwamena
- Duke University, Department of Psychology and Neuroscience, Durham, North Carolina, United States
| | - Kanghyun Kim
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Kyung Chul Lee
- Seoul National University, Department of Mechanical Engineering, Seoul, Republic of Korea
- Seoul National University, School of Mechanical & Aerospace Engineering/SNU-IAMD, Seoul, Republic of Korea
| | - Kyle R. Cowdrick
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Wenhui Liu
- Tsinghua University, Department of Automation, Beijing, China
| | - Arin Ülkü
- École polytechnique fédérale de Lausanne (EPFL), Advanced Quantum Architecture Laboratory, Neuchatel, Switzerland
| | - Mark Harfouche
- Ramona Optics, Inc., Durham, North Carolina, United States
| | - Xi Yang
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Clare Cook
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Seung Ah Lee
- Seoul National University, Department of Mechanical Engineering, Seoul, Republic of Korea
| | - Erin Buckley
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Claudio Bruschini
- École polytechnique fédérale de Lausanne (EPFL), Advanced Quantum Architecture Laboratory, Neuchatel, Switzerland
| | - Edoardo Charbon
- École polytechnique fédérale de Lausanne (EPFL), Advanced Quantum Architecture Laboratory, Neuchatel, Switzerland
| | - Scott Huettel
- Duke University, Department of Psychology and Neuroscience, Durham, North Carolina, United States
| | - Roarke Horstmeyer
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
- Ramona Optics, Inc., Durham, North Carolina, United States
| |
Collapse
|
2
|
Mahler S, Huang YX, Ismagilov M, Álvarez-Chou D, Abedi A, Tyszka JM, Lo YT, Russin J, Pantera RL, Liu C, Yang C. Portable six-channel laser speckle system for simultaneous measurement of cerebral blood flow and volume with potential applications in characterization of brain injury. NEUROPHOTONICS 2025; 12:015003. [PMID: 39867132 PMCID: PMC11758243 DOI: 10.1117/1.nph.12.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2024] [Revised: 12/30/2024] [Accepted: 01/02/2025] [Indexed: 01/28/2025]
Abstract
Significance Cerebral blood flow (CBF) and cerebral blood volume (CBV) are key metrics for regional cerebrovascular monitoring. Simultaneous, non-invasive measurement of CBF and CBV at different brain locations would advance cerebrovascular monitoring and pave the way for brain injury detection as current brain injury diagnostic methods are often constrained by high costs, limited sensitivity, and reliance on subjective symptom reporting. Aim We aim to develop a multi-channel non-invasive optical system for measuring CBF and CBV at different regions of the brain simultaneously with a cost-effective, reliable, and scalable system capable of detecting potential differences in CBF and CBV across different regions of the brain. Approach The system is based on speckle contrast optical spectroscopy and consists of laser diodes and board cameras, which have been both tested and investigated for safe use on the human head. Apart from the universal serial bus connection for the camera, the entire system, including its battery power source, is integrated into a wearable headband and is powered by 9-V batteries. Results The temporal dynamics of both CBF and CBV in a cohort of five healthy subjects were synchronized and exhibited similar cardiac period waveforms across all six channels. The potential use of our six-channel system for detecting the physiological sequelae of brain injury was explored in two subjects, one with moderate and one with significant structural brain damage, where the six-point CBF and CBV measurements were referenced to structural magnetic resonance imaging (MRI) scans. Conclusions We pave the way for a viable multi-point optical instrument for measuring CBF and CBV. Its cost-effectiveness allows for baseline metrics to be established prior to injury in populations at risk for brain injury.
Collapse
Affiliation(s)
- Simon Mahler
- California Institute of Technology, Department of Electrical Engineering, Pasadena, California, United States
| | - Yu Xi Huang
- California Institute of Technology, Department of Electrical Engineering, Pasadena, California, United States
| | - Max Ismagilov
- California Institute of Technology, Department of Electrical Engineering, Pasadena, California, United States
| | - David Álvarez-Chou
- California Institute of Technology, Department of Electrical Engineering, Pasadena, California, United States
| | - Aidin Abedi
- University of Southern California, USC Neurorestoration Center and Department of Neurological Surgery, Los Angeles, California, United States
| | - J. Michael Tyszka
- California Institute of Technology, Division of Humanities and Social Sciences, Pasadena, California, United States
| | - Yu Tung Lo
- University of Southern California, USC Neurorestoration Center and Department of Neurological Surgery, Los Angeles, California, United States
| | - Jonathan Russin
- University of Southern California, USC Neurorestoration Center and Department of Neurological Surgery, Los Angeles, California, United States
- Rancho Los Amigos National Rehabilitation Center, Downey, California, United States
| | - Richard L. Pantera
- Kaweah Health Medical Center, Neurology, Visalia, California, United States
| | - Charles Liu
- University of Southern California, USC Neurorestoration Center and Department of Neurological Surgery, Los Angeles, California, United States
- Rancho Los Amigos National Rehabilitation Center, Downey, California, United States
| | - Changhuei Yang
- California Institute of Technology, Department of Electrical Engineering, Pasadena, California, United States
| |
Collapse
|
3
|
Bharadwaj S, Urner TM, Cowdrick KR, Brothers RO, Boodooram T, Zhao H, Goyal V, Sathialingam E, Wu YC, Quadri A, Turrentine K, Akbar MM, Triplett SE, Bai S, Buckley EM. Stand-alone segmentation of blood flow pulsatility measured with diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:6052-6062. [PMID: 39421785 PMCID: PMC11482157 DOI: 10.1364/boe.533916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 09/04/2024] [Accepted: 09/07/2024] [Indexed: 10/19/2024]
Abstract
We present a stand-alone blood flow index (BFI) pulse segmentation method for diffuse correlation spectroscopy that uses a wavelet-based representation of the BFI signal at the cardiac frequency in place of an exogenous physiological reference. We use this wavelet-based segmentation method to quantify BFI waveform morphology in a cohort of 30 healthy adults. We demonstrate that the waveform morphology features obtained with the wavelet approach strongly agree with those obtained using an exogenous blood pressure reference signal. These results suggest the promise of stand-alone wavelet-based BFI segmentation for quantifying BFI waveform morphological features.
Collapse
Affiliation(s)
- Srinidhi Bharadwaj
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Tara M. Urner
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Kyle R. Cowdrick
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Rowan O. Brothers
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Tisha Boodooram
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Hongting Zhao
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Vidisha Goyal
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Eashani Sathialingam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Yueh-Chi Wu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Ayesha Quadri
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Katherine Turrentine
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Mariam M. Akbar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Sydney E. Triplett
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Shasha Bai
- Department of Pediatrics, Emory School of Medicine, Atlanta, Georgia 30322, USA
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
- Department of Pediatrics, Emory School of Medicine, Atlanta, Georgia 30322, USA
- Children's Research Scholar, Children's Healthcare of Atlanta, 2015 Uppergate Dr., Atlanta, Georgia 30322, USA
| |
Collapse
|
4
|
Wang Q, Pan M, Kreiss L, Samaei S, Carp SA, Johansson JD, Zhang Y, Wu M, Horstmeyer R, Diop M, Li DDU. A comprehensive overview of diffuse correlation spectroscopy: Theoretical framework, recent advances in hardware, analysis, and applications. Neuroimage 2024; 298:120793. [PMID: 39153520 DOI: 10.1016/j.neuroimage.2024.120793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 07/23/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024] Open
Abstract
Diffuse correlation spectroscopy (DCS) is a powerful tool for assessing microvascular hemodynamic in deep tissues. Recent advances in sensors, lasers, and deep learning have further boosted the development of new DCS methods. However, newcomers might feel overwhelmed, not only by the already-complex DCS theoretical framework but also by the broad range of component options and system architectures. To facilitate new entry to this exciting field, we present a comprehensive review of DCS hardware architectures (continuous-wave, frequency-domain, and time-domain) and summarize corresponding theoretical models. Further, we discuss new applications of highly integrated silicon single-photon avalanche diode (SPAD) sensors in DCS, compare SPADs with existing sensors, and review other components (lasers, sensors, and correlators), as well as data analysis tools, including deep learning. Potential applications in medical diagnosis are discussed and an outlook for the future directions is provided, to offer effective guidance to embark on DCS research.
Collapse
Affiliation(s)
- Quan Wang
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Mingliang Pan
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Lucas Kreiss
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Saeed Samaei
- Department of Medical and Biophysics, Schulich School of Medical & Dentistry, Western University, London, Ontario, Canada; Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Stefan A Carp
- Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States
| | | | - Yuanzhe Zhang
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Melissa Wu
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Roarke Horstmeyer
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Mamadou Diop
- Department of Medical and Biophysics, Schulich School of Medical & Dentistry, Western University, London, Ontario, Canada; Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - David Day-Uei Li
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom.
| |
Collapse
|
5
|
Baker WB, Forti RM, Heye P, Heye K, Lynch JM, Yodh AG, Licht DJ, White BR, Hwang M, Ko TS, Kilbaugh TJ. Modified Beer-Lambert algorithm to measure pulsatile blood flow, critical closing pressure, and intracranial hypertension. BIOMEDICAL OPTICS EXPRESS 2024; 15:5511-5532. [PMID: 39296411 PMCID: PMC11407241 DOI: 10.1364/boe.529150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 08/12/2024] [Accepted: 08/12/2024] [Indexed: 09/21/2024]
Abstract
We introduce a frequency-domain modified Beer-Lambert algorithm for diffuse correlation spectroscopy to non-invasively measure flow pulsatility and thus critical closing pressure (CrCP). Using the same optical measurements, CrCP was obtained with the new algorithm and with traditional nonlinear diffusion fitting. Results were compared to invasive determination of intracranial pressure (ICP) in piglets (n = 18). The new algorithm better predicted ICP elevations; the area under curve (AUC) from logistic regression analysis was 0.85 for ICP ≥ 20 mmHg. The corresponding AUC for traditional analysis was 0.60. Improved diagnostic performance likely results from better filtering of extra-cerebral tissue contamination and measurement noise.
Collapse
Affiliation(s)
- Wesley B Baker
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rodrigo M Forti
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pascal Heye
- Division of General, Thoracic and Fetal Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Kristina Heye
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jennifer M Lynch
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arjun G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel J Licht
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Prenatal Pediatrics, Children's National, Washington DC, USA
| | - Brian R White
- Division of Pediatric Cardiology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Misun Hwang
- Department of Radiology, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tiffany S Ko
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Todd J Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
6
|
Cheng TY, Kim B, Zimmermann BB, Robinson MB, Renna M, Carp SA, Franceschini MA, Boas DA, Cheng X. Choosing a camera and optimizing system parameters for speckle contrast optical spectroscopy. Sci Rep 2024; 14:11915. [PMID: 38789499 PMCID: PMC11126420 DOI: 10.1038/s41598-024-62106-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Speckle contrast optical spectroscopy (SCOS) is an emerging camera-based technique that can measure human cerebral blood flow (CBF) with high signal-to-noise ratio (SNR). At low photon flux levels typically encountered in human CBF measurements, camera noise and nonidealities could significantly impact SCOS measurement SNR and accuracy. Thus, a guide for characterizing, selecting, and optimizing a camera for SCOS measurements is crucial for the development of next-generation optical devices for monitoring human CBF and brain function. Here, we provide such a guide and illustrate it by evaluating three commercially available complementary metal-oxide-semiconductor cameras, considering a variety of factors including linearity, read noise, and quantization distortion. We show that some cameras that are well-suited for general intensity imaging could be challenged in accurately quantifying spatial contrast for SCOS. We then determine the optimal operating parameters for the preferred camera among the three and demonstrate measurement of human CBF with this selected low-cost camera. This work establishes a guideline for characterizing and selecting cameras as well as for determining optimal parameters for SCOS systems.
Collapse
Affiliation(s)
- Tom Y Cheng
- Department of Biomedical Engineering, Neurophotonics Center, Boston University, Boston, MA, 02215, USA
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, 02421, USA
| | - Byungchan Kim
- Department of Biomedical Engineering, Neurophotonics Center, Boston University, Boston, MA, 02215, USA
| | - Bernhard B Zimmermann
- Department of Biomedical Engineering, Neurophotonics Center, Boston University, Boston, MA, 02215, USA
| | - Mitchell B Robinson
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Marco Renna
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Stefan A Carp
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Maria Angela Franceschini
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - David A Boas
- Department of Biomedical Engineering, Neurophotonics Center, Boston University, Boston, MA, 02215, USA
| | - Xiaojun Cheng
- Department of Biomedical Engineering, Neurophotonics Center, Boston University, Boston, MA, 02215, USA.
| |
Collapse
|
7
|
Gómez CA, Brochard L, Goligher EC, Rozenberg D, Reid WD, Roblyer D. Combined frequency domain near-infrared spectroscopy and diffuse correlation spectroscopy system for comprehensive metabolic monitoring of inspiratory muscles during loading. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:035002. [PMID: 38532926 PMCID: PMC10965138 DOI: 10.1117/1.jbo.29.3.035002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024]
Abstract
Significance Mechanical ventilation (MV) is a cornerstone technology in the intensive care unit as it assists with the delivery of oxygen in critically ill patients. The process of weaning patients from MV can be long and arduous and can lead to serious complications for many patients. Despite the known importance of inspiratory muscle function in the success of weaning, current clinical standards do not include direct monitoring of these muscles. Aim The goal of this project was to develop and validate a combined frequency domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS) system for the noninvasive characterization of inspiratory muscle response to a load. Approach The system was fabricated by combining a custom digital FD-NIRS and DCS system. It was validated via liquid phantom titrations and a healthy volunteer study. The sternocleidomastoid (SCM), an accessory muscle of inspiration, was monitored during a short loading period in fourteen young, healthy volunteers. Volunteers performed two different respiratory exercises, a moderate load and a high load, which consisted of a one-minute baseline, a one-minute load, and a six-minute recovery period. Results The system has low crosstalk between absorption, reduced scattering, and flow when tested in a set of liquid titrations. Faster dynamics were observed for changes in blood flow index (BF i ), and metabolic rate of oxygen (MRO 2 ) compared with hemoglobin + myoglobin (Hb+Mb) based parameters after the onset of loads in males. Additionally, larger percent changes in BF i , and MRO 2 were observed compared with Hb+Mb parameters in both males and females. There were also sex differences in baseline values of oxygenated Hb+Mb, total Hb+Mb, and tissue saturation. Conclusions The dynamic characteristics of Hb+Mb concentration and blood flow were distinct during loading of the SCM, suggesting that the combination of FD-NIRS and DCS may provide a more complete picture of inspiratory muscle dynamics.
Collapse
Affiliation(s)
- Carlos A. Gómez
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Laurent Brochard
- St. Michael’s Hospital, Unity Health Toronto, Li Ka Shing Knowledge Institute, Keenan Research Centre, Toronto, Ontario, Canada
- St. Michael’s Hospital, Department of Critical Care, Toronto, Ontario, Canada
- University of Toronto, Interdepartmental Division of Critical Care Medicine, Toronto, Ontario, Canada
| | - Ewan C. Goligher
- University of Toronto, Interdepartmental Division of Critical Care Medicine, Toronto, Ontario, Canada
- University Health Network, Toronto General Hospital Research Institute, Toronto, Ontario, Canada
- University of Toronto, Department of Physiology, Toronto, Ontario, Canada
| | - Dmitry Rozenberg
- University Health Network, Toronto General Hospital Research Institute, Ajmera Transplant Center, Toronto, Ontario, Canada
- University of Toronto, Division of Respirology, Temerty Faculty of Medicine, Toronto, Ontario, Canada
| | - W. Darlene Reid
- University of Toronto, Department of Physical Therapy, Toronto, Ontario, Canada
- University of Toronto, Interdepartmental Division of Critical Care Medicine, Toronto, Ontario, Canada
- University Health Network, KITE – Toronto Rehabilitation Institute, Toronto, Ontario, Canada
| | - Darren Roblyer
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| |
Collapse
|
8
|
Zavriyev AI, Kaya K, Wu KC, Pierce ET, Franceschini MA, Robinson MB. Measuring pulsatile cortical blood flow and volume during carotid endarterectomy. BIOMEDICAL OPTICS EXPRESS 2024; 15:1355-1369. [PMID: 38495722 PMCID: PMC10942688 DOI: 10.1364/boe.507730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 03/19/2024]
Abstract
Carotid endarterectomy (CEA) involves removal of plaque in the carotid artery to reduce the risk of stroke and improve cerebral perfusion. This study aimed to investigate the utility of assessing pulsatile blood volume and flow during CEA. Using a combined near-infrared spectroscopy/diffuse correlation spectroscopy instrument, pulsatile hemodynamics were assessed in 12 patients undergoing CEA. Alterations to pulsatile amplitude, pulse transit time, and beat morphology were observed in measurements ipsilateral to the surgical side. The additional information provided through analysis of pulsatile hemodynamic signals has the potential to enable the discovery of non-invasive biomarkers related to cortical perfusion.
Collapse
Affiliation(s)
- Alexander I. Zavriyev
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kutlu Kaya
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kuan Cheng Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Eric T. Pierce
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria Angela Franceschini
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mitchell B. Robinson
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|