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Meskin M, Starkey PA, Kaspersen AE, Ringgaard S, Sand SG, Nygaard JV, Jensen JA, Traberg MS, Johansen P. Investigating the importance of left atrial compliance on fluid dynamics in a novel mock circulatory loop. Sci Rep 2024; 14:1864. [PMID: 38253772 PMCID: PMC10803730 DOI: 10.1038/s41598-024-52327-6] [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: 09/11/2023] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
The left atrium (LA) hemodynamic indices hold prognostic value in various cardiac diseases and disorders. To understand the mechanisms of these conditions and to assess the performance of cardiac devices and interventions, in vitro models can be used to replicate the complex physiological interplay between the pulmonary veins, LA, and left ventricle. In this study, a comprehensive and adaptable in vitro model was created. The model includes a flexible LA made from silicone and allows distinct control over the systolic and diastolic functions of both the LA and left ventricle. The LA was mechanically matched with porcine LAs through expansion tests. Fluid dynamic measures were validated against the literature and pulmonary venous flows recorded on five healthy individuals using magnetic resonance flow imaging. Furthermore, the fluid dynamic measures were also used to construct LA pressure-volume loops. The in vitro pressure and flow recordings expressed a high resemblance to physiological waveforms. By decreasing the compliance of the LA, the model behaved realistically, elevating the a- and v-wave peaks of the LA pressure from 12 to 19 mmHg and 22 to 26 mmHg, respectively, while reducing the S/D ratio of the pulmonary venous flowrate from 1.5 to 0.3. This model provides a realistic platform and framework for developing and evaluating left heart procedures and interventions.
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Affiliation(s)
- Masoud Meskin
- Cardiovascular Biomechanics Group, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | - Philip Alexander Starkey
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | | | | | - Signe Gram Sand
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | - Jens Vinge Nygaard
- Biomechanics and Mechanobiology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Marie Sand Traberg
- Cardiovascular Biomechanics Group, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Peter Johansen
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark.
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Mendez K, Kennedy DG, Wang DD, O’Neill B, Roche ET. Left Atrial Appendage Occlusion: Current Stroke Prevention Strategies and a Shift Toward Data-Driven, Patient-Specific Approaches. JOURNAL OF THE SOCIETY FOR CARDIOVASCULAR ANGIOGRAPHY & INTERVENTIONS 2022; 1:100405. [PMID: 39131471 PMCID: PMC11308563 DOI: 10.1016/j.jscai.2022.100405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/08/2022] [Accepted: 06/14/2022] [Indexed: 08/13/2024]
Abstract
The left atrial appendage (LAA) is a complex structure with unknown physiologic function protruding from the main body of the left atrium. In patients with atrial fibrillation, the left atrium does not contract effectively. Insufficient atrial and LAA contractility predisposes the LAA morphology to hemostasis and thrombus formation, leading to an increased risk of cardioembolic events. Oral anticoagulation therapies are the mainstay of stroke prevention options for patients; however, not all patients are candidates for long-term oral anticoagulation. Percutaneous occlusion devices are an attractive alternative to long-term anticoagulation therapy, although they are not without limitations, such as peri-implant leakage and device-related thrombosis. Although efforts have been made to reduce these risks, significant interpatient heterogeneity inevitably yields some degree of device-anatomy mismatch that is difficult to resolve using current devices and can ultimately lead to insufficient occlusion and poor patient outcomes. In this state-of-the-art review, we evaluated the anatomy of the LAA as well as the current pathophysiologic understanding and stroke prevention strategies used in the management of the risk of stroke associated with atrial fibrillation. We highlighted recent advances in computed tomography imaging, preprocedural planning, computational modeling, and novel additive manufacturing techniques, which represent the tools needed for a paradigm shift toward patient-centric LAA occlusion. Together, we envisage that these techniques will facilitate a pipeline from the imaging of patient anatomy to patient-specific computational and bench-top models that enable customized, data-driven approaches for LAA occlusion that are engineered specifically to meet each patient's unique needs.
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Affiliation(s)
- Keegan Mendez
- Harvard/MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Darragh G. Kennedy
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Biomedical Engineering, Columbia University, New York, New York
| | | | | | - Ellen T. Roche
- Harvard/MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
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3
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Zhao X, Zhao L, Xu J, Li D, Li H, Li Y, Chen H, Zhang Y. Aortic valve opening in mock-loop with continuous-flow left ventricular assist device. Int J Artif Organs 2022; 45:809-816. [PMID: 35818176 DOI: 10.1177/03913988221111811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The appropriate opening of aortic valves is crucial for heart failure (HF) patients with left ventricular assist devices (LVADs). Nevertheless, up to the present time, aortic valve monitoring has not been performed in discharged patients. In this study, a mock-loop platform was developed to investigate the aortic valve performance in LVAD patients. An additional sluice valve was placed next to the aortic valve that when the sluice valve is manually closed, the aortic valve will remain closed; when the sluice valve is open, the aortic valve is opened or closed upon the pressures. The results showed that when the LVAD speed was below 2600 rpm, the aortic valve can be intermittently opened, while when the LVAD speed was over 2600 rpm, the aortic valve was persistently closed. The left ventricular end-systolic pressure (LVESP) was found to be an indicator of aortic valve closure that, upon the aortic valve closure LVESP suddenly decreased. The LVESP is suggested for future monitoring the status of the aortic valve for patients with implanted LVADs. The effects of heart failure (HF) degrees, circulation resistance, and aortic compliance on aortic valve closure were further studied. The results revealed that LVAD implantation in patients with early HF degrees will help to avoid persistent aortic valve closure.
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Affiliation(s)
- Xiang Zhao
- School of Medicine, Tsinghua University (School of Medicine) - RocketHeart Co. Ltd Joint Research Center for Artificial Heart, Tsinghua University, Beijing, China.,School of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Luxiang Zhao
- School of Medicine, Tsinghua University (School of Medicine) - RocketHeart Co. Ltd Joint Research Center for Artificial Heart, Tsinghua University, Beijing, China.,School of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Jian Xu
- School of Medicine, Tsinghua University (School of Medicine) - RocketHeart Co. Ltd Joint Research Center for Artificial Heart, Tsinghua University, Beijing, China
| | - Donghai Li
- Advanced Medical Research Institute, Shandong University, Shandong, China
| | - Heping Li
- Department of Engineering Physics, Tsinghua University, Beijing, China
| | - Yongjian Li
- School of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Haosheng Chen
- School of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Yu Zhang
- School of Medicine, Tsinghua University (School of Medicine) - RocketHeart Co. Ltd Joint Research Center for Artificial Heart, Tsinghua University, Beijing, China
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Tasca G, Sturla F, Jaworek M, Giese D, Menicanti L, Vismara R, Lombardi M, Redaelli A. In vitro four-dimensional flow magnetic resonance analysis of the effect of pericardial valve design on aortic flow. J Med Eng Technol 2022; 46:209-219. [DOI: 10.1080/03091902.2022.2026505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Giordano Tasca
- Cardiac Surgery Department, Heart Health Center, King Saud Medical City, Riyadh, Kingdom of Saudi Arabia
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Francesco Sturla
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Michal Jaworek
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | | | - Lorenzo Menicanti
- Cardiac Surgery Department, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Riccardo Vismara
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Massimo Lombardi
- Multimodality Cardiac Imaging, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
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5
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Liu GM, Jiang FQ, Song JP, Hu SS. Intraventricular flow visualization in different heart failure stages with blood pump support in a mock circulatory loop. Int J Artif Organs 2021; 44:773-782. [PMID: 34382479 DOI: 10.1177/03913988211021432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The intraventricular blood flow changed by blood pump flow dynamics may correlate with thrombosis and ventricular suction. The flow velocity, distribution of streamlines, vorticity, and standard deviation of velocity inside a left ventricle failing to different extents throughout the cardiac cycle when supported by an axial blood pump were measured by particle image velocimetry (PIV) in this study. The results show slower and static flow velocities existed in the central region of the left ventricle near the mitral valve and aortic valve and that were not sensitive to left ventricular (LV) failure degree or LV pressure. Strong vorticity located near the inner LV wall around the LV apex and the blood pump inlet was not sensitive to LV failure degree or LV pressure. Higher standard deviation of the blood velocity at the blood pump inlet decreased with increasing LV failure degree, whereas the standard deviation of the velocity near the atrium increased with increasing intraventricular pressure. The experimental results demonstrated that the risk of thrombosis inside the failing left ventricle is not related to heart failure degree. The "washout" performance of the strong vorticity near the inner LV wall could reduce the thrombotic potential inside the left ventricle and was not related to heart failure degree. The vorticity near the aortic valve was sensitive to LV failure degree but not to LV pressure. We concluded that the risk of blood damage caused by adverse flow inside the left ventricle decreased with increasing LV pressure.
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Affiliation(s)
- Guang-Mao Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fu-Qing Jiang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Adult Cardiac Surgery, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | - Jiang-Ping Song
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Adult Cardiac Surgery, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | - Sheng-Shou Hu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Adult Cardiac Surgery, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
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6
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Liu GM, Jiang FQ, Yang XH, Wei RJ, Hu SS. Experimental investigation of the influence of the hydraulic performance of an axial blood pump on intraventricular blood flow. Int J Artif Organs 2021; 44:980-989. [PMID: 33908310 DOI: 10.1177/03913988211013046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Blood flow inside the left ventricle (LV) is a concern for blood pump use and contributes to ventricle suction and thromboembolic events. However, few studies have examined blood flow inside the LV after a blood pump was implanted. In this study, in vitro experiments were conducted to emulate the intraventricular blood flow, such as blood flow velocity, the distribution of streamlines, vorticity and the standard deviation of velocity inside the LV during axial blood pump support. A silicone LV reconstructed from computerized tomography (CT) data of a heart failure patient was incorporated into a mock circulatory loop (MCL) to simulate human systemic circulation. Then, the blood flow inside the ventricle was examined by particle image velocimetry (PIV) equipment. The results showed that the operating conditions of the axial blood pump influenced flow patterns within the LV and areas of potential blood stasis, and the intraventricular swirling flow was altered with blood pump support. The presence of vorticity in the LV from the thoracic aorta to the heart apex can provide thorough washing of the LV cavity. The gradually extending stasis region in the central LV with increasing blood pump support is necessary to reduce the thrombosis potential in the LV.
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Affiliation(s)
- Guang-Mao Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | - Fu-Qing Jiang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | - Xiao-Han Yang
- Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | | | - Sheng-Shou Hu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
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7
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Sturla F, Piatti F, Jaworek M, Lucherini F, Pluchinotta FR, Siryk SV, Giese D, Vismara R, Tasca G, Menicanti L, Redaelli A, Lombardi M. 4D Flow MRI hemodynamic benchmarking of surgical bioprosthetic valves. Magn Reson Imaging 2020; 68:18-29. [PMID: 31981709 DOI: 10.1016/j.mri.2020.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/23/2019] [Accepted: 01/19/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE We exploited 4-dimensional flow magnetic resonance imaging (4D Flow), combined with a standardized in vitro setting, to establish a comprehensive benchmark for the systematic hemodynamic comparison of surgical aortic bioprosthetic valves (BPVs). MATERIALS AND METHODS 4D Flow analysis was performed on two small sizes of three commercialized pericardial BPVs (Trifecta™ GT, Carpentier-Edwards PERIMOUNT Magna and Crown PRT®). Each BPV was tested over a clinically pertinent range of continuous flow rates within an in vitro MRI-compatible system, equipped with pressure transducers. In-house 4D Flow post-processing of the post-valvular velocity field included the quantification of BPV effective orifice area (EOA), transvalvular pressure gradients (TPG), kinetic energy and viscous energy dissipation. RESULTS The 4D Flow technique effectively captured the 3-dimensional flow pattern of each device. Trifecta exhibited the lowest range of velocity and kinetic energy, maximized EOA (p < 0.0001) and minimized TPGs (p ≤ 0.015) if compared with Magna and Crown, these reporting minor EOA difference s (p ≥ 0.042) and similar TPGs (p ≥ 0.25). 4D Flow TPGs estimations strongly correlated against ground-truth data from pressure transducers; viscous energy dissipation proved to be inversely proportional to the fluid jet penetration. CONCLUSION The proposed 4D Flow analysis pinpointed consistent hemodynamic differences among BPVs, highlighting the not negligible effect of device size on the fluidynamic outcomes. The efficacy of non-invasive 4D Flow MRI protocol could shed light on how standardize the comparison among devices in relation to their actual hemodynamic performances and improve current criteria for their selection.
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Affiliation(s)
- Francesco Sturla
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy.
| | - Filippo Piatti
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Michal Jaworek
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Federico Lucherini
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Francesca R Pluchinotta
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy; Multimodality Cardiac Imaging, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; Department of Pediatric and Adult Congenital Heart Disease, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Sergii V Siryk
- CONCEPT Lab, Istituto Italiano di Tecnologia, Genova, Italy
| | | | - Riccardo Vismara
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Giordano Tasca
- Cardiac Surgery Unit, Heart Health Center, King Saud Medical City, Riyadh, Saudi Arabia
| | - Lorenzo Menicanti
- Department of Cardiovascular Disease, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Massimo Lombardi
- Multimodality Cardiac Imaging, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
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8
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King JM, Bergeron CA, Taylor CE. Development of an adaptive pulmonary simulator for in vitro analysis of patient populations and patient-specific data. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2018; 161:93-102. [PMID: 29852971 DOI: 10.1016/j.cmpb.2018.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 03/14/2018] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND OBJECTIVE Patient-specific modeling (PSM) is gaining more attention from researchers due to its ability to potentially improve diagnostic capabilities, guide the design of intervention procedures, and optimize clinical management by predicting the outcome of a particular treatment and/or surgical intervention. Due to the hemodynamic diversity of specific patients, an adaptive pulmonary simulator (PS) would be essential for analyzing the possible impact of external factors on the safety, performance, and reliability of a cardiac assist device within a mock circulatory system (MCS). In order to accurately and precisely replicate the conditions within the pulmonary system, a PS should not only account for the ability of the pulmonary system to supply blood flow at specific pressures, but similarly consider systemic outflow dynamics. This would provide an accurate pressure and flow rate return supply back into the left ventricular section of the MCS (i.e. the initial conditions of the left heart). METHODS Employing an embedded Windkessel model, a control system model was developed utilizing MathWorks' Simulink® Simscape™. Following a verification and validation (V&V) analysis approach, a PI-controlled closed-loop hydraulic system was developed using Simscape™. This physical system modeling tool was used to (1) develop and control the in silico system during verification studies and (2) simulate pulmonary performance for validation of this control architecture. RESULTS The pulmonary Windkessel model developed is capable of generating the left atrial pressure (LAP) waveform from given pulmonary factors, aortic conditions, and systemic variables. Verification of the adaptive PS's performance and validation of this control architecture support this modeling methodology as an effective means of reproducing pulmonary pressure waveforms and systemic outflow conditions, unique to a particular patient. Adult and geriatric with and without Heart Failure and a Normal Ejection Fraction (HFNEF) are presented. CONCLUSIONS The adaptability of this modelling approach allows for the simulation of pulmonary conditions without the limitations of a dedicated hardware platform for use in in vitro investigations.
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Affiliation(s)
- Jacob M King
- Cajun Artificial Heart Laboratory, Mechanical Engineering Department, University of Louisiana at Lafayette, 241 E. Lewis St. RM320, Lafayette, LA 70503, United States
| | - Clint A Bergeron
- Cajun Artificial Heart Laboratory, Mechanical Engineering Department, University of Louisiana at Lafayette, 241 E. Lewis St. RM320, Lafayette, LA 70503, United States
| | - Charles E Taylor
- Cajun Artificial Heart Laboratory, Mechanical Engineering Department, University of Louisiana at Lafayette, 241 E. Lewis St. RM320, Lafayette, LA 70503, United States.
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Abstract
Currently, clinicians are seeking new, minimally invasive treatment options for functional tricuspid regurgitation (FTR). Challenging tricuspid complexity requires the evaluation of the treatment techniques in adequate and realistic preclinical scenario. The purpose of this article is to describe the design and functional assessment of a novel passive beating heart model of the pulmonary circulation with the possibility to tightly control FTR. The model housed porcine hearts actuated by a volumetric pump that cyclically pressurized the right ventricle. The in-vitro FTR model exploited the tendency of the ventricle to dilate under pressure. The dilation entailed papillary muscles displacement and valve annulus enlargement, thus inducing tricuspid valve insufficiency. Employment of constraint bands allowed to restore valve competency. The system provided consistent replication of the main determinants of the pulmonary hemodynamics in a wide range of working conditions. The experimental model of FTR was reliable, easily controllable, and showed good stability-over-time. Echocardiography and fiberscope imaging provided a unique opportunity to investigate valve dynamics. These features make the platform suitable for realistic training purposes and testing of the upcoming FTR therapies.
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Hydrodynamic and Geometric Behavior of Two Pericardial Prostheses Implanted in Small Aortic Roots. ASAIO J 2017; 64:86-90. [PMID: 28475560 DOI: 10.1097/mat.0000000000000587] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Hydrodynamic performance of stented bioprostheses is far below that of the native valve. One of the reasons is that the internal diameter of the prosthesis is usually smaller than that of the native valve. However, other valve characteristics are also important in generating the pressure drop. We aimed to assess, in an ex vivo pulsatile mock loop, the hydrodynamic behavior of two bioprostheses, Trifecta and Mitroflow, to ascertain which geometric terms are limiting factors in hydrodynamic performance. At stroke volumes between 30 and 60 ml, Trifecta showed lower pressure drop, energy dissipation and valve resistance, and greater effective orifice area. This trend was overturned at higher stroke volumes, with Mitroflow slightly outperforming Trifecta. The geometric determinants were consistent with these results. Trifecta achieved its maximum opening area already at the lowest stroke volumes, featuring a divergent shape at the systolic peak. Mitroflow showed a complex opening pattern, featuring a convergent shape at the systolic peak for lower stroke volumes, while reaching its maximum opening area at higher stroke volumes, with a divergent shape. The two bioprostheses, although similar in design, displayed different biomechanical behaviors. The internal diameter of each bioprosthesis did not show to be strictly correlated with its hydrodynamic characteristics.
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Piola M, Vismara R, Tasca G, Lucherini F, Redaelli P, Soncini M, Romagnoni C, Mangini A, Antona C, Fiore GB. Design of a simple coronary impedance simulator for thein vitrostudy of the complex coronary hemodynamics. Physiol Meas 2016; 37:2274-2285. [DOI: 10.1088/1361-6579/37/12/2274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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12
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Fluid-Structure Interaction Study of Transcatheter Aortic Valve Dynamics Using Smoothed Particle Hydrodynamics. Cardiovasc Eng Technol 2016; 7:374-388. [PMID: 27844463 DOI: 10.1007/s13239-016-0285-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/04/2016] [Indexed: 10/20/2022]
Abstract
Computational modeling of heart valve dynamics incorporating both fluid dynamics and valve structural responses has been challenging. In this study, we developed a novel fully-coupled fluid-structure interaction (FSI) model using smoothed particle hydrodynamics (SPH). A previously developed nonlinear finite element (FE) model of transcatheter aortic valves (TAV) was utilized to couple with SPH to simulate valve leaflet dynamics throughout the entire cardiac cycle. Comparative simulations were performed to investigate the impact of using FE-only models vs. FSI models, as well as an isotropic vs. an anisotropic leaflet material model in TAV simulations. From the results, substantial differences in leaflet kinematics between FE-only and FSI models were observed, and the FSI model could capture the realistic leaflet dynamic deformation due to its more accurate spatial and temporal loading conditions imposed on the leaflets. The stress and the strain distributions were similar between the FE and FSI simulations. However, the peak stresses were different due to the water hammer effect induced by the fluid inertia in the FSI model during the closing phase, which led to 13-28% lower peak stresses in the FE-only model compared to that of the FSI model. The simulation results also indicated that tissue anisotropy had a minor impact on hemodynamics of the valve. However, a lower tissue stiffness in the radial direction of the leaflets could reduce the leaflet peak stress caused by the water hammer effect. It is hoped that the developed FSI models can serve as an effective tool to better assess valve dynamics and optimize next generation TAV designs.
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13
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Tasca G, Vismara R, Mangini A, Romagnoni C, Contino M, Redaelli A, Fiore GB, Antona C. Comparison of the Performance of a Sutureless Bioprosthesis With Two Pericardial Stented Valves on Small Annuli: An In Vitro Study. Ann Thorac Surg 2016; 103:139-144. [PMID: 27544288 DOI: 10.1016/j.athoracsur.2016.05.089] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 03/21/2016] [Accepted: 05/23/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND Aortic valve replacement has evolved recently with the development of the sutureless bioprosthesis. One such valve is the Perceval bioprosthesis, which is built by mounting leaflets of bovine pericardium to a thin stent; this approach has the potential to provide an excellent fluid dynamic performance. We undertook an in vitro study to compare the hydrodynamic performance of the sutureless bioprosthesis with two standard pericardial stented bioprostheses (Crown and Magna). METHODS Tests were conducted using a mock loop, testing on two sizes of the three prostheses. The prosthesis sizes were chosen to house the valves in porcine aortic roots with a native annulus diameter of 19 mm (n = 6) or 21 mm (n = 6). The stroke volume ranged from 25 mL to 105 mL at a simulated heart rate of 70 beats per minute. RESULTS Mean pressure drop and energy loss rose with increasing stroke volume in all of the valves tested (p < 0.001), with the sutureless valve showing the lowest values for both variables (p < 0.001). Effective orifice area values were stable across the stroke volume intervals and were larger in the sutureless valves (p < 0.001). CONCLUSIONS All of the valves tested provided good fluid dynamic performances. The sutureless bioprosthesis provided the best performance with the least hindrance to flow behavior. From the hydrodynamic perspective, the sutureless prosthesis may present an advance in the evolution of bioprostheses, ensuring low gradients and potential for low incidence of patient-prosthesis mismatch even in small annuli.
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Affiliation(s)
- Giordano Tasca
- Cardiovascular Department, Cardiac Surgery Unit, Ospedale "A. Manzoni" di Lecco, Lecco; Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan.
| | - Riccardo Vismara
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan; FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan
| | - Andrea Mangini
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan; FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan; Cardiovascular Surgery Department, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy
| | - Claudia Romagnoni
- FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan; Cardiovascular Surgery Department, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy
| | - Monica Contino
- FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan; Cardiovascular Surgery Department, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy
| | - Alberto Redaelli
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan; FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan
| | - Gianfranco Beniamino Fiore
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan; FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan
| | - Carlo Antona
- FoRCardioLab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan; Cardiovascular Surgery Department, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy
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Tasca G, Fiore GB, Mangini A, Romagnoni C, Gamba A, Redaelli A, Antona C, Vismara R. Opening–closing pattern of four pericardial prostheses: results from an in vitro study of leaflet kinematics. J Artif Organs 2016; 19:350-356. [DOI: 10.1007/s10047-016-0910-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
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Vismara R, Leopaldi AM, Piola M, Asselta C, Lemma M, Antona C, Redaelli A, van de Vosse F, Rutten M, Fiore GB. In vitro assessment of mitral valve function in cyclically pressurized porcine hearts. Med Eng Phys 2016; 38:346-53. [PMID: 26908180 DOI: 10.1016/j.medengphy.2016.01.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 12/22/2015] [Accepted: 01/31/2016] [Indexed: 11/25/2022]
Abstract
Recent approaches to the in vitro experimental study of cardiac fluid mechanics involve the use of whole biological structures to investigate in the lab novel therapeutic approaches for the treatment of heart pathologies. To enhance reliability and repeatability, the influence of the actuation strategy of the experimental apparatuses on the biomechanics of biological structures needs to be assessed. Using echography and intracardiac high-speed imaging, we compared the mitral valve (MV) anatomo-functional features (coaptation areas/lengths, papillary muscles-valvular plane distances) in two passive-beating-heart mock loops with internal (IPML) or external (EPML) pressurization of the ventricular chamber. Both apparatuses showed fluid dynamic conditions that closely resembled the physiology. The MVs analyzed in the EPML presented coaptation areas and lengths that were systematically higher, and exhibited greater variability from early-to peak-systole, as compared to those in the IPML. Moreover, in the EPML, the MV leaflets exhibited a convexity with high curvature toward the atrium. With the IPML, MV coaptation lengths ranged similar to available clinical data and the papillary muscles-valve plane distances were more stable throughout systole. In conclusion, both the apparatuses allow for reproducing in vitro the left heart hemodynamics, in terms of flow rates and pressures, with proper mitral valve continence. Results suggest that the IPML is more suitable for replicating the physiological MV functioning, while the EPML may have more potential as a model for the study of MV pathologies.
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Affiliation(s)
- Riccardo Vismara
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy .
| | | | - Marco Piola
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Chiara Asselta
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Massimo Lemma
- Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy ; Cardiovascular Surgery Department, 'Luigi Sacco' University general Hospital, Milan, Italy
| | - Carlo Antona
- Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy ; Cardiovascular Surgery Department, 'Luigi Sacco' University general Hospital, Milan, Italy ; Università degli Studi di Milano, Milan, Italy
| | - Alberto Redaelli
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy
| | - Frans van de Vosse
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Marcel Rutten
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gianfranco B Fiore
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy
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Does the type of suture technique affect the fluid-dynamic performance of bioprostheses implanted in small aortic roots? Results from an in vitro study. J Thorac Cardiovasc Surg 2015; 149:912-8. [DOI: 10.1016/j.jtcvs.2014.10.096] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 11/23/2022]
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Leopaldi AM, Vismara R, van Tuijl S, Redaelli A, van de Vosse FN, Fiore GB, Rutten MCM. A novel passive left heart platform for device testing and research. Med Eng Phys 2015; 37:361-6. [PMID: 25666402 DOI: 10.1016/j.medengphy.2015.01.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 11/17/2014] [Accepted: 01/17/2015] [Indexed: 10/24/2022]
Abstract
Integration of biological samples into in vitro mock loops is fundamental to simulate real device's operating conditions. We developed an in vitro platform capable of simulating the pumping function of the heart through the external pressurization of the ventricle. The system consists of a fluid-filled chamber, in which the ventricles are housed and sealed to exclude the atria from external loads. The chamber is connected to a pump that drives the motion of the ventricular walls. The aorta is connected to a systemic impedance simulator, and the left atrium to an adjustable preload. The platform reproduced physiologic hemodynamics, i.e. aortic pressures of 120/80 mmHg with 5 L/min of cardiac output, and allowed for intracardiac endoscopy. A pilot study with a left ventricular assist device (LVAD) was also performed. The LVAD was connected to the heart to investigate aortic valve functioning at different levels of support. Results were consistent with the literature, and high speed video recordings of the aortic valve allowed for the visualization of the transition between a fully opening valve and a permanently closed configuration. In conclusion, the system showed to be an effective tool for the hemodynamic assessment of devices, the simulation of surgical or transcatheter procedures and for visualization studies.
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Affiliation(s)
- A M Leopaldi
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy; LifeTec Group, Cardiovascular Department, Eindhoven, The Netherlands.
| | - R Vismara
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - S van Tuijl
- LifeTec Group, Cardiovascular Department, Eindhoven, The Netherlands
| | - A Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - F N van de Vosse
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - G B Fiore
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - M C M Rutten
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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Tasca G, Vismara R, Fiore GB, Mangini A, Romagnoni C, Pelenghi S, Antona C, Redaelli A, Gamba A. Fluid-dynamic results of in vitro comparison of four pericardial bioprostheses implanted in small porcine aortic roots. Eur J Cardiothorac Surg 2014; 47:e62-7. [DOI: 10.1093/ejcts/ezu446] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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In vitro study of a standardized approach to aortic cusp extension. Int J Artif Organs 2014; 37:315-24. [PMID: 24811186 DOI: 10.5301/ijao.5000316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE Cusp extension technique (CET) is a reparative surgical procedure for restoring aortic valve function by suturing patches to the compromised native leaflets. Its outcomes are strongly dependent on the ability of the surgeon. We proposed and tested a novel approach on an in vitro model, aimed at standardizing and simplifying the surgical procedure. METHODS A set of standard pre-cut bovine pericardium patches, available in different sizes, was developed. The surgeon can choose the leaflet-specific patches to be implanted according to the patient anatomy, using a geometrical model of the aortic valve whose inputs are the measured intercommissural distances. The hemodynamic performance of this approach was evaluated on porcine aortic roots in a pulsatile mock loop. Hydrodynamic and kinematic evaluation of the samples was provided. RESULTS After CET, mean and maximum pressure drops were 3.1±1.3 mmHg and 25.4±5.0 mmHg respectively, and EOA was 3.8±0.8 cm. CONCLUSIONS Our approach to cusp extension proved to be reliable and effective in restoring valve functioning, without significantly altering the physiological kinematics. The use of pre-cut patches considerably simplified the surgery, increasing standardization and repeatability.
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Vismara R, Leopaldi A, Mangini A, Romagnoni C, Contino M, Antona C, Fiore G. In vitro study of the aortic interleaflet triangle reshaping. J Biomech 2014; 47:329-33. [DOI: 10.1016/j.jbiomech.2013.11.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/31/2013] [Accepted: 11/21/2013] [Indexed: 10/26/2022]
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Sumikura H, Nakayama Y, Ohnuma K, Takewa Y, Tatsumi E. In Vitro Evaluation of a Novel Autologous Aortic Valve (Biovalve) With a Pulsatile Circulation Circuit. Artif Organs 2013; 38:282-9. [DOI: 10.1111/aor.12173] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Hirohito Sumikura
- Department of Artificial Organs; National Cerebral and Cardiovascular Center Research Institute; Suita Osaka Japan
| | - Yasuhide Nakayama
- Department of Biomedical Engineering; National Cerebral and Cardiovascular Center Research Institute; Suita Osaka Japan
| | - Kentaro Ohnuma
- Department of Artificial Organs; National Cerebral and Cardiovascular Center Research Institute; Suita Osaka Japan
| | - Yoshiaki Takewa
- Department of Artificial Organs; National Cerebral and Cardiovascular Center Research Institute; Suita Osaka Japan
| | - Eisuke Tatsumi
- Department of Artificial Organs; National Cerebral and Cardiovascular Center Research Institute; Suita Osaka Japan
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Leopaldi AM, Vismara R, Lemma M, Valerio L, Cervo M, Mangini A, Contino M, Redaelli A, Antona C, Fiore GB. In vitro hemodynamics and valve imaging in passive beating hearts. J Biomech 2012; 45:1133-9. [PMID: 22387122 DOI: 10.1016/j.jbiomech.2012.02.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 02/03/2012] [Accepted: 02/08/2012] [Indexed: 10/28/2022]
Abstract
Due to their high complexity, surgical approaches to valve repair may benefit from the use of in vitro simulators both for training and for the investigation of those measures which can lead to better clinical results. In vitro tests are intrinsically more effective when all the anatomical substructures of the valvular complexes are preserved. In this work, a mock apparatus able to house an entire explanted porcine heart and subject it to pulsatile fluid-dynamic conditions was developed, in order to enable the hemodynamic analysis of simulated surgical procedures and the imaging of the valvular structures. The mock loop's hydrodynamic design was based on an ad-hoc defined lumped-parameter model. The left ventricle of an entire swine heart was dynamically pressurized by an external computer-controlled pulse duplicator. The ascending aorta was connected to a hydraulic circuit which simulated the input impedance of the systemic circulation; a reservoir passively filled the left atrium. Accesses for endoscopic imaging were located in the apex of the left ventricle and in the aortic root. The experimental pressure and flow tracings were comparable with the typical in vivo curves; a mean flow of 3.5±0.1l pm and a mean arterial pressure of 101±2 mmHg was obtained. High-quality echographic and endoscopic video recordings demonstrated the system's excellent potential in the observation of the cardiac structures dynamics. The proposed mock loop represents a suitable in vitro system for the testing of minimally-invasive cardiovascular devices and surgical procedures for heart valve repair.
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Affiliation(s)
- A M Leopaldi
- ForCardio.Lab, Università di Milano, Politecnico di Milano, Milano, Italy.
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de Kerchove L, Vismara R, Mangini A, Fiore GB, Price J, Noirhomme P, Antona C, El Khoury G. In vitro comparison of three techniques for ventriculo-aortic junction annuloplasty. Eur J Cardiothorac Surg 2012; 41:1117-23; discussion 1123-4. [DOI: 10.1093/ejcts/ezr237] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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A pulsatile simulator for the in vitro analysis of the mitral valve with tri-axial papillary muscle displacement. Int J Artif Organs 2011; 34:383-91. [PMID: 21534249 DOI: 10.5301/ijao.2011.7729] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE We developed a new pulsatile hydrodynamic simulator for the in vitro testing of mitral valve (MV) samples. The required specifications included a 3D positioning system for the papillary muscles (PMs) that is accurate and simple to manage; measurement of the force exerted by the chordae tendineae on the PMs; and the possibility to visually inspect the MV for kinematic analysis. METHODS An atrial/ventricular chamber system was developed. The ventricular chamber housed a tri-axial actuator system that was aligned to a morphometric Cartesian frame, allowing for PM positioning even while tests are running. Each PM holder had an embedded load cell for force measurement. The atrial chamber was designed so as to permit MV visual inspection, maintaining a non-disturbed flow at the sample inlet. The setup was subjected to trials with fresh porcine MVs. Flow and pressure difference across the MVs and PM forces were measured in different MV configurations, with different PM spatial dislocations. High speed video recordings were acquired. RESULTS The positioning accuracy was assessed. Tests with MVs showed good usability, even by the non-engineering personnel. The effects of PM displacement on valve function (valve competence and PM forces) was consistent with previously published data, thus confirming the general soundness of the design principles. CONCLUSIONS The developed simulator is a promising instrument for performing MV in vitro tests in a precise, well-repeatable manner. The ability to completely adjust the PM position while a test is running boosts the simulator's potential for detailed investigations of the pathological and surgically treated MV.
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In Vitro Study of Aortic Valves Treated with Neo-Chordae Grafts: Hydrodynamics and Tensile Force Measurements. Ann Biomed Eng 2011; 39:1024-31. [DOI: 10.1007/s10439-010-0235-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 12/18/2010] [Indexed: 11/25/2022]
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