James Antaki
Cornell University, Meinig School of Biomedical Engineering, Faculty Member
- Professor, Biomedical Engineeringedit
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Research Interests: Engineering, Mechanical Engineering, Applied Mathematics, Algorithms, Biomedical Engineering, and 9 moreKalman Filter, Humans, Computer Simulation, Coronary Circulation, Estimator, Extended Kalman Filter, Continuous Flow Heart Assist Devices, Electrical And Electronic Engineering, and Medical and Health Sciences
Research Interests: Computer Science, Algorithms, Materials Science, Biomedical Engineering, Artificial Organs, and 15 moreMedicine, Quality Control, Humans, Transducers, Hemodynamics, Sheep, Pubmed, Animals, Clinical Sciences, prosthesis Design, Continuous Flow Heart Assist Devices, Equipment Design, Blood Flow Velocity, Transducer, and Preload
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The quality of life of patients relying on electrically powered artificial organs is currently restricted by the limited energy availability provided by portable batteries. As these patients become increasingly ambulatory, and are... more
The quality of life of patients relying on electrically powered artificial organs is currently restricted by the limited energy availability provided by portable batteries. As these patients become increasingly ambulatory, and are developing more active lifestyles, this limitation grows more apparent. Coincidentally, these patients may themselves be capable of generating electrical power as a consequence of their physical activity. Extraction of this latent autologous energy could, in turn, be used to augment charging of internal batteriesthus untethering the patient from external power for extended periods of time. In this study, the viability of deriving energy associated with natural human ambulation has been evaluated. The kinematic components of gait were evaluated to identify the largest useful forces and moments that may be harnessed as an energy source, while presenting
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Abdur Rub Abdur Rahman Kingsley Eromoses Abhulimen John Patrick Abraham Steven Abramowitch Ziad O. Abu-Faraj Memis Acar Judith Adams Klaus Affeld Anant Agrawal Guillermo Aguilar Shandar Ahmad Bummo Ahn Tabassum Ahsan Lisong Ai Santiago... more
Abdur Rub Abdur Rahman Kingsley Eromoses Abhulimen John Patrick Abraham Steven Abramowitch Ziad O. Abu-Faraj Memis Acar Judith Adams Klaus Affeld Anant Agrawal Guillermo Aguilar Shandar Ahmad Bummo Ahn Tabassum Ahsan Lisong Ai Santiago Aja-Fernandez Mustafa Akdis Mohammed P. Akhter Ata Akin Alptekin Aksan Ian G. Aldous Ahmed M. Al-Jumaily Kyle D. Allen Alejandro Almarza Jose Alvarez Rui Alves Manoel Alves Paulo Eduardo Ambrosio Amir A. Amini Jennifer R. Amos M. Andersen Charles Anderson Andrew Anderson Stelios Andreadis James F. Antaki Luca Antiga David Antonetti Mark Appleford Robert Appleyard George Archontis K. P. Arkill Antonis A. Armoundas Allison Arnold-Rife Theo M. G. J. Arts M. G. Ascenzi Bahman Asgharian Sara Assecondi Anand R. Asthagiri Krishna Asundi Gerard H. A. Ateshian Said H. Audi Bruno Averbeck Alberto Avolio Vibhudutta Awasthi Leon Axel Ali Azarbarzin Robert Azencott Keith Baar Abbas Babajani Stephen F. Badylak Sriram Balasubramanian J. Ballyns Peter Bannerman Zhirong Bao Gilda A. Barabino Danny Baranes Riccardo Barbieri Berj L. Bardakjian Roger C. Barr Efrath Barta Ward Bartels Cameron Bass Jason H. T. Bates Mathias Baumert Scott Beardsley Jacques Beaumont Khosrow Behbehani Marek Behr Essy Behravesh Jose Bernal Joel Berry Thor Besier Walter Grant Besio Anne Beuter Michael J. Bey Anastasios G. Bezerianos Archana Bhat Kristen Lawrence Billiar Ravi K. Birla Ruediger Blindt Guido Boerrigter Stephane Bolduc Harvey S. Borovetz Edward Botchwey Fergal Boyle Christoph Braun Audrius Brazdeikis Michael Breen Liam Breen Lori Bridal Mathias Brieu Gerd Brunner Stephanie Bryant Thomas Budinger William Buford, Jr. Joseph L. Bull P. Buma Laura Burattini Jason Burdick Monica Burdick Greg Burgreen Thomas Burkholder T. R. Bush Oguz Buskurt Bill Bussone Jonathan Butcher James Butler Ruggero Cadossi B. Calvo Jon Camp Lisa Marie Campana Michael R. Caplan Dana Carpenter Rupp Carriveau Gráinne T. Carroll Josh Cates Juan Raul Cebral Pietro Cerveri Mario Cesarelli Niranjan Chakravarthy V. S. Chakravarthy John Challis Rosa H. M. Chan Eric Chan Krishnan B. Chandran Shyang Chang W. Art Chaovalitwongse P. Bryant Chase George P. Chatzimavroudis Kinon Chen Xin Chen Huafu Chen Annals of Biomedical Engineering, Vol. 39, No. 2, February 2011 ( 2011) pp. 594–599 DOI: 10.1007/s10439-011-0251-3
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Two designs of an outlet stator for the Nimbus axial flow left ventricular assist device (LVAD) are analyzed at nominal operating conditions. The original stator assembly (Design 1) has significant flow separation and reversal. A second... more
Two designs of an outlet stator for the Nimbus axial flow left ventricular assist device (LVAD) are analyzed at nominal operating conditions. The original stator assembly (Design 1) has significant flow separation and reversal. A second stator assembly (Design 2) replaces the original tubular outer housing with a converging-diverging throat section with the intention of locally improving the fluid dynamics. Both stator designs are analyzed using computational fluid dynamics (CFD) analysis and experimental particle imaging flow visualization (PIFV). The computational and experimental methods indicate: 1) persistent regions of flow separation in Design 1 and improved fluid dynamics in Design 2; 2) blade-toblade velocity fields that are well organized at the blade tip yet chaotic at the blade hub for both designs; and 3) a moderate decrease in pressure recovery for Design 2 as compared with Design 1. The CFD analysis provides the necessary insight to identify a subtle, localized flow acceleration responsible for the decreased hydraulic efficiency of Design 2. In addition, the curiously low thrombogenicity of Design 1 is explained by the existence of a three-dimensional unsteady vortical flow structure that enhances boundary advection.
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<p>The red dots signify Optimal unloading, denoted with corresponding LVAD speed (kRPM). (b) Unimodal (ascending-descending) preload response resembles clinically observed severe LV dysfunction reported by Ross and Braunwald <a... more
<p>The red dots signify Optimal unloading, denoted with corresponding LVAD speed (kRPM). (b) Unimodal (ascending-descending) preload response resembles clinically observed severe LV dysfunction reported by Ross and Braunwald <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Ross1" target="_blank">[12]</a>. The shaded region indicates envelope of marked heart dysfunction defined by Ross and Braunwald, and based on the response of LV SWI to volume unloading in five of their patients (JW, MD, CC, IG, RS).</p
Research Interests: Engineering, Bioengineering, Physics, Biophysics, Biomedical Engineering, and 13 moreCardiovascular, Medicine, Simulation, Heart Failure, Anatomy and Physiology, Hemodynamics, Medical devices, Cardiovascular system, LVAD, Cardiomyopathies, Circulatory physiology, Biological Systems Engineering, and Time varying
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ABSTRACT
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<p>(a) Normal patient; (b) pre-operative clinical LVAD data versus simulation baseline of LVF and LVF with PVR+; (c) pre-operative BiVAD patient data versus simulation baseline of Bi-F and Bi-F with PVR+ conditions. Values are... more
<p>(a) Normal patient; (b) pre-operative clinical LVAD data versus simulation baseline of LVF and LVF with PVR+; (c) pre-operative BiVAD patient data versus simulation baseline of Bi-F and Bi-F with PVR+ conditions. Values are represented as mean +/− standard deviation. (Sources: Rulli et al. 1980 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Kovacs1" target="_blank">[30]</a>, € Nordenfelt et al. 1985 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Nordenfelt1" target="_blank">[31]</a>, Normal range for MAP <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Carey1" target="_blank">[28]</a>£; Ehrsam et al. 1983 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Ehrsam1" target="_blank">[32]</a>, ! Zaret et al. 1984 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Zaret1" target="_blank">[33]</a>,¥ Thadani et al. 1978 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Thadani1" target="_blank">[34]</a>, * Dang et al. 2006 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Dang1" target="_blank">[26]</a>; Fitzpatrick et al. 2008 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Fitzpatrick2" target="_blank">[27]</a>; Kormos et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085234#pone.0085234-Kormos2" target="_blank">[29]</a>). All of the abbreviation are defined in Section II, Part C.</p
Research Interests: Engineering, Bioengineering, Physics, Biophysics, Biomedical Engineering, and 14 moreCardiovascular, Medicine, Simulation, Heart Failure, Anatomy and Physiology, Hemodynamics, Medical devices, Cardiovascular system, Published, Cardiomyopathies, Circulatory physiology, Biological Systems Engineering, Pathological, and baseline
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A new suction detection system for rotary blood pumps used in left ventricular assist devices is presented. The system is based on frequency indices combined with a time-frequency extraction feature algorithm. The frequency based indices... more
A new suction detection system for rotary blood pumps used in left ventricular assist devices is presented. The system is based on frequency indices combined with a time-frequency extraction feature algorithm. The frequency based indices can detect the changes in the harmonic and subharmonic energy content of the pump flow signal, when a suction event is occurring. The time-frequency extraction feature algorithm can track variations in the standard deviation of the instantaneous frequency of that signal. These two pieces of information are then combined in a weighted decision system to generate a suction alarm. The proposed system has been tested in simulations, in a mock-loop system, and in-vivo tests and produced very satisfactory results
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... Intelligent Control Design for Heart Assist Devices JR Boston, Marwan A. Simaan, James F. Antalu, Yih-Choung Yu, Seongjin Choi Department of Electrical Engineering and the McGowen Artificial Organ Center University of Pittsburgh,... more
... Intelligent Control Design for Heart Assist Devices JR Boston, Marwan A. Simaan, James F. Antalu, Yih-Choung Yu, Seongjin Choi Department of Electrical Engineering and the McGowen Artificial Organ Center University of Pittsburgh, Pittsburgh, PA 15261 ABSTRACT ...
Research Interests: Cardiology, Intelligent Control, Adaptive Control, Heart, Receiving Operating Characteristic, and 11 moreControl Structure, Continuous Flow, Optimal Control Problem, Multidimensional Systems, Intelligent Sensors, Adaptive Algorithm, Control Algorithm, Heuristic algorithm, Assistive Device, Cardiac output, and Left Ventricular
... JR Boston&amp;#x27;, Marwan A. Simaan&amp;#x27;, James F. Antaki&amp;#x27;, Yih-Choung Yu3 Department of Electrical Engineering, *McGowen Artificial Organ Center University of Pittsburgh, Pittsburgh, PA 15261 and 3Cardiac... more
... JR Boston&amp;#x27;, Marwan A. Simaan&amp;#x27;, James F. Antaki&amp;#x27;, Yih-Choung Yu3 Department of Electrical Engineering, *McGowen Artificial Organ Center University of Pittsburgh, Pittsburgh, PA 15261 and 3Cardiac Assist Technologies, Inc. Pittsburgh, PA 15238 boston@ee. pitt. edu 1 ...
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ABSTRACT A mathematical model describing the pressure-volume relationship of the Novacor left ventricular assist system (LVAS) was developed. The model consisted of lumped resistance, capacitance, and inductance elements with one... more
ABSTRACT A mathematical model describing the pressure-volume relationship of the Novacor left ventricular assist system (LVAS) was developed. The model consisted of lumped resistance, capacitance, and inductance elements with one time-varying capacitor to simulate the cyclical pressure generation of the system. The ejection and filling portions of the pump cycle were modeled with two separate functions. The corresponding model parameters were estimated by least squares fit to experimental data obtained in the laboratory. The model performed well in simulating pump pressure of operation throughout the full cycle. This model can be used to incorporate online cardiovascular model parameter estimation and to design a rule-based controller for the LVAS
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... Support Yih-Choung Yu&amp;#x27;, J. Robert Boston2J, Marwan A. Simaan&amp;#x27;, James F. A ~ ~ taki ~ . ~ ... on Biomed. Eng., 42, 1165-1 172. Mandarino, W. A., J. Gorcsan 111, T. A. Gasior, S. Pham, B. Griffith, and RL... more
... Support Yih-Choung Yu&amp;#x27;, J. Robert Boston2J, Marwan A. Simaan&amp;#x27;, James F. A ~ ~ taki ~ . ~ ... on Biomed. Eng., 42, 1165-1 172. Mandarino, W. A., J. Gorcsan 111, T. A. Gasior, S. Pham, B. Griffith, and RL Kormos (1995). Estimation ...
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Mathematical models of thrombosis are currently used to study clinical scenarios of pathological thrombus formation. Most of these models involve inherent uncertainties that must be assessed to increase the confidence in model predictions... more
Mathematical models of thrombosis are currently used to study clinical scenarios of pathological thrombus formation. Most of these models involve inherent uncertainties that must be assessed to increase the confidence in model predictions and identify avenues of improvement for both thrombosis modeling and anti-platelet therapies. In this work, an uncertainty quantification analysis of a multi-constituent thrombosis model is performed considering a common assay for platelet function (PFA-100). The analysis is performed using a polynomial chaos expansion as a parametric surrogate for the thrombosis model. The polynomial approximation is validated and used to perform a global sensitivity analysis via computation of Sobol' coefficients. Six out of fifteen parameters were found to be influential in the simulation variability considering only individual effects. Nonetheless, parameter interactions are highlighted when considering the total Sobol' indices. In addition to the sensi...
To investigate potentially prothrombotic flow patterns within an axial flow ventricular assist device under clinically relevant pulsatile hemodynamic conditions. A transparent replica of the HeartMate-II left ventricular assist device... more
To investigate potentially prothrombotic flow patterns within an axial flow ventricular assist device under clinically relevant pulsatile hemodynamic conditions. A transparent replica of the HeartMate-II left ventricular assist device (Thoratec, Pleasanton, Calif) was visualized using a high speed camera at both low and high frame rates (125 and 3000 fps). Three steady-state conditions were studied: nominal (4.5 lpm), low flow (3.0 lpm), and high flow (6.0 lpm). Time-varying conditions were introduced with an external pulsatile pump that modulated the flow rate by approximately ±50% of the mean, corresponding to a pulsatility index of 1.0. At nominal and high flow rates, the path lines within the upstream region were generally stable, well attached, and streamlined. As the flow rate was reduced below 3.8 lpm, a rapid transition to a chaotic velocity field occurred, exhibiting a large toroidal vortex adjacent to the upstream bearing. The pathlines in the downstream stator section wer...
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Current risk stratification models to predict outcomes after a left ventricular assist device (LVAD) are limited in scope. We assessed the performance of Bayesian models to stratify post-LVAD mortality across various International... more
Current risk stratification models to predict outcomes after a left ventricular assist device (LVAD) are limited in scope. We assessed the performance of Bayesian models to stratify post-LVAD mortality across various International Registry for Mechanically Assisted Circulatory Support (INTERMACS or IM) Profiles, device types, and implant strategies. We performed a retrospective analysis of 10,206 LVAD patients recorded in the IM registry from 2012 to 2016. Using derived Bayesian algorithms from 8,222 patients (derivation cohort), we applied the risk-prediction algorithms to the remaining 2,055 patients (validation cohort). Risk of mortality was assessed at 1, 3, and 12 months post implant according to disease severity (IM profiles), device type (axial versus centrifugal) and strategy (bridge to transplantation or destination therapy). Fifteen percentage (n = 308) were categorized as IM profile 1, 36% (n = 752) as profile 2, 33% (n = 672) as profile 3, and 15% (n = 311) as profile 4-7 in the validation cohort. The Bayesian algorithms showed good discrimination for both short-term (1 and 3 months) and long-term (1 year) mortality for patients with severe HF (Profiles 1-3), with the receiver operating characteristic area under the curve (AUC) between 0.63 and 0.74. The algorithms performed reasonably well in both axial and centrifugal devices (AUC, 0.68-0.74), as well as bridge to transplantation or destination therapy indication (AUC, 0.66-0.73). The performance of the Bayesian models at 1 year was superior to the existing risk models. Bayesian algorithms allow for risk stratification after LVAD implantation across different IM profiles, device types, and implant strategies.
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Spontaneous pneumothorax (SP) is uncommon and can present as a primary disease process or as a result of underlying lung pathology. Several parenchymal lung diseases, such as malignancy, are known to cause SP. One such malignancy,... more
Spontaneous pneumothorax (SP) is uncommon and can present as a primary disease process or as a result of underlying lung pathology. Several parenchymal lung diseases, such as malignancy, are known to cause SP. One such malignancy, angiosarcoma, has a high propensity to metastasize to the lung and present as cavitary and cystic lesions. We present a case of a 76-year-old male diagnosed with angiosarcoma of the scalp that was found to have extensive cystic pulmonary metastatic lesions. Soon after his initial diagnosis, he presented with severe respiratory distress secondary to a spontaneous left-sided pneumothorax. After intubation and left-sided chest tube placement, the patient developed a right-sided tension pneumothorax requiring emergent chest tube placement. Cutaneous angiosarcoma is a rare malignancy that frequently metastasizes the lung. Spontaneous pneumothorax can be the presenting manifestation of the disease and often results in respiratory failure.
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Research Interests: Risk assessment, Medicine, Heart Failure, Humans, Female, and 13 moreMale, Body Mass Index, Sodium, Retrospective Studies, Age Factors, Risk Assessment, Bayes Theorem, Continuous Flow Heart Assist Devices, Vascular Resistance, Serum albumin, Pulmonary Artery, tricuspid valve insufficiency, and leukocyte Count
In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The... more
In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and reactions of 10 chemical and biological species are incorporated using a system of coupled convection-reaction-diffusion (CRD) equations to represent three processes in thrombus formation: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: in vivo thrombus growth in an injured blood vessel and in vitro thrombus deposition in micro-channels (1.5mm x 1.6mm x 0.1mm) with small crevices (125μm x 75μm and 125μm x 137μm). For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. Based on the success with these two benchmark problems, which have ver...
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ASAIO lournjl /992 SLIDE FORUM 10 CIRCULATORY ASSIST/NEW DESIGNS Development of an Axial Flow Blood Pump LVAS Kenneth С Butler,* Tim R. Maher,* Harvey S. Borovetz,! Robert L. Kormos,! James F. Antaki,t Marina Kameneva,! Bartley P.... more
ASAIO lournjl /992 SLIDE FORUM 10 CIRCULATORY ASSIST/NEW DESIGNS Development of an Axial Flow Blood Pump LVAS Kenneth С Butler,* Tim R. Maher,* Harvey S. Borovetz,! Robert L. Kormos,! James F. Antaki,t Marina Kameneva,! Bartley P. Griffith,! Tony Zerbe,t and ...
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This paper introduces a certainty-weighted detection system (CWDS) based on distributed decision makers that can classify a binary phenomenon as true, false, or uncertain. The CWDS is composed of two main blocks: the definite decision... more
This paper introduces a certainty-weighted detection system (CWDS) based on distributed decision makers that can classify a binary phenomenon as true, false, or uncertain. The CWDS is composed of two main blocks: the definite decision block (DDB), which provides a decision regarding the presence or absence of the phenomenon, and the uncertainty measure block (UMB) that provides a measure of uncertainty. The final decision, which may be definite (true or false) or uncertain, depends on characteristic parameters that define the region of uncertainty (and) used by piece-wise linear certainty functions in the DDB and in the UMB. Bayes cost analysis is extended to include the cost of uncertain classifications and the cost of errors. A cost function is used to compare the CWDS to decision structures based on Dempster-Shafer and fuzzy logic that also provide uncertain decisions. The CWDS performs similarly to a classical Bayes detection system (CBDS) when no uncertain classifications are provided. By changing the parameters and , the CWDS can also be adjusted to perform similarly to the Dempster-Shafer and fuzzy structures. The differences between these approaches are mainly in their characterization of uncertainty, and they can reduce the total costs below that of the Bayesian model if the cost of uncertain classifications is sufficiently smaller than the cost of errors. The performance of the CWDS was less sensitive to changes in the ratio of the costs of uncertain decisions to the cost of incorrect certain decisions, showing the CWDS to be more robust to system parameters than the fuzzy and Dempster-Shafer systems.
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ABSTRACT Summary form only given. Feedback control of mechanical circulatory support can either be very simple, or extraordinarily complicated. The sophistication of algorithms fundamentally depends on the requirements for safety and... more
ABSTRACT Summary form only given. Feedback control of mechanical circulatory support can either be very simple, or extraordinarily complicated. The sophistication of algorithms fundamentally depends on the requirements for safety and efficacy. As patients are treated through staged levels of therapy: from the critical care setting to the home, the demands for control vary - as do the availability of data. Turbodynamic pumps present an additional challenge, as compared to their positive-displacement counterparts, due to their relative lack of local, intrinsic, control. Due to the nonlinearity of the plant, and the wide variability of hemodynamic disturbances, no definitive method of control has yet been determined. Common features of all controllers have been to optimize perfusion within the limits of venous return; in some sense, to mimic the Frank-Starling law of the heart. However, unlike the native heart, turbodynamic pumps have the ability to outstrip venous return, creating suction pressure within the ventricle. Attendant risks of tissue damage have therefore lead to the development of algorithms for detecting suction. The difficulty of this task is however compounded by the questionable long-term reliability of indwelling sensors, which may introduce additional, unacceptable failure modes. This presentation will provide a survey of the current strategies under development and remaining challenges.
Research Interests: Computer Science and IEEE
Research Interests: Mathematics, Computer Science, Medicine, Differential Equations, Blood Pressure, and 13 moreBiocontrol, Heart rate, Mathematical Model, Cardiovascular system, Haemodynamics, Human Activity, Baroreflex, Differential equation, Experimental Data, Time varying, Arterial pressure, Couplings, and Left Ventricular
The advantages of hemodynamic pulsatility are still controversial based on the evaluation of normal organ function under varying perfusion conditions. The development of the permanent nonpulsatile blood pump as a left ventricular assist... more
The advantages of hemodynamic pulsatility are still controversial based on the evaluation of normal organ function under varying perfusion conditions. The development of the permanent nonpulsatile blood pump as a left ventricular assist device (LVAD) demands that the efficacy of pulseless perfusion in the recovery of end-organ function is verified. This study examined hemodynamic power as an index of mechanical forces applied to the blood, and also the recovery of renal function following a 30-min period of normothermic ischemia. Pigs were randomized into four groups. In all groups, acute renal ischemia was induced by clamping both renal arteries for 30 min. Reperfusion for 120 min was performed using either pulsatile perfusion, or pulseless perfusion at 65 ± 1.6 mmHg (groups I and II respectively) or 40 ± 1.1 mmHg (groups III and IV respectively). After reperfusion, renal blood flow (RBF) and hemodynamic power (HP = ∫P(t) · Q(t)dt, where P is renal artery pressure and Q is renal artery flow) in groups I, II, and III were significantly higher than in Group IV (P < 0.01 by analysis of variance). In terms of renal functional recovery, there was a significant positive correlation between hemodynamic power and renal oxygen consumption (VO 2) (r = 0.96, P < 0.01). It was concluded that high HP is important for promoting peripheral circulation. Under hypotensive conditions, pulsatile perfusion is more effective in delivering HP to the organ compared with pulseless perfusion.