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Gwosch T, Magkoutas K, Kaiser D, Schmid Daners M. Performance and Reliable Operation of Physiological Controllers Under Various Cardiovascular Models: In Silico and In Vitro Study. ASAIO J 2024; 70:485-494. [PMID: 38373197 DOI: 10.1097/mat.0000000000002143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024] Open
Abstract
The evaluation of control schemes for left ventricular assist devices (LVADs) requires the utilization of an appropriate model of the human cardiovascular system. Given that different patients and experimental data yield varying performance of the cardiovascular models (CVMs) and their respective parameters, it becomes crucial to assess the reliable operation of controllers. This study aims to assess the performance and reliability of various LVAD controllers using two state-of-the-art CVMs, with a specific focus on the impact of interpatient variability. Extreme test cases were employed for evaluation, incorporating both in silico and in vitro experiments. The differences observed in response between the studied CVMs can be attributed to variations in their structures and parameters. Specifically, the model with smaller compartments exhibits higher overload rates, whereas the other model demonstrates increased sensitivity to changes in preload and afterload, resulting in more frequent suction events (34.2% vs. 8.5% for constant speed mode). These findings along with the varying response of the tested controllers highlight the influence of the selected CVM emphasizing the need to test each LVAD controller with multiple CVMs or, at least, a range of parameter sets. This approach ensures sufficient evaluation of the controller's efficacy in addressing interpatient variability.
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Affiliation(s)
- Thomas Gwosch
- From the Product Development Group Zurich, ETH Zurich, Zurich, Switzerland
| | | | - David Kaiser
- From the Product Development Group Zurich, ETH Zurich, Zurich, Switzerland
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2
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Magkoutas K, Nunes Rossato L, Heim M, Schmid Daners M. Genetic algorithm-based optimization framework for control parameters of ventricular assist devices. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2023.104788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
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3
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Xu KW, Gao Q, Wan M, Zhang K. Mock circulatory loop applications for testing cardiovascular assist devices and in vitro studies. Front Physiol 2023; 14:1175919. [PMID: 37123281 PMCID: PMC10133581 DOI: 10.3389/fphys.2023.1175919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/03/2023] [Indexed: 05/02/2023] Open
Abstract
The mock circulatory loop (MCL) is an in vitro experimental system that can provide continuous pulsatile flows and simulate different physiological or pathological parameters of the human circulation system. It is of great significance for testing cardiovascular assist device (CAD), which is a type of clinical instrument used to treat cardiovascular disease and alleviate the dilemma of insufficient donor hearts. The MCL installed with different types of CADs can simulate specific conditions of clinical surgery for evaluating the effectiveness and reliability of those CADs under the repeated performance tests and reliability tests. Also, patient-specific cardiovascular models can be employed in the circulation of MCL for targeted pathological study associated with hemodynamics. Therefore, The MCL system has various combinations of different functional units according to its richful applications, which are comprehensively reviewed in the current work. Four types of CADs including prosthetic heart valve (PHV), ventricular assist device (VAD), total artificial heart (TAH) and intra-aortic balloon pump (IABP) applied in MCL experiments are documented and compared in detail. Moreover, MCLs with more complicated structures for achieving advanced functions are further introduced, such as MCL for the pediatric application, MCL with anatomical phantoms and MCL synchronizing multiple circulation systems. By reviewing the constructions and functions of available MCLs, the features of MCLs for different applications are summarized, and directions of developing the MCLs are suggested.
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Affiliation(s)
- Ke-Wei Xu
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, China
| | - Qi Gao
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, China
- *Correspondence: Qi Gao,
| | - Min Wan
- Shandong Institute of Medical Device and Pharmaceutical Packaging Inspection, Jinan, China
| | - Ke Zhang
- Shandong Institute of Medical Device and Pharmaceutical Packaging Inspection, Jinan, China
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4
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Magkoutas K, Arm P, Meboldt M, Schmid Daners M. Physiologic Data-Driven Iterative Learning Control for Left Ventricular Assist Devices. Front Cardiovasc Med 2022; 9:922387. [PMID: 35911509 PMCID: PMC9326058 DOI: 10.3389/fcvm.2022.922387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 06/20/2022] [Indexed: 11/25/2022] Open
Abstract
Continuous flow ventricular assist devices (cfVADs) constitute a viable and increasingly used therapy for end-stage heart failure patients. However, they are still operating at a fixed-speed mode that precludes physiological cfVAD response and it is often related to adverse events of cfVAD therapy. To ameliorate this, various physiological controllers have been proposed, however, the majority of these controllers do not account for the lack of pulsatility in the cfVAD operation, which is supposed to be beneficial for the physiological function of the cardiovascular system. In this study, we present a physiological data-driven iterative learning controller (PDD-ILC) that accurately tracks predefined pump flow trajectories, aiming to achieve physiological, pulsatile, and treatment-driven response of cfVADs. The controller has been extensively tested in an in-silico environment under various physiological conditions, and compared with a physiologic pump flow proportional-integral-derivative controller (PF-PIDC) developed in this study as well as the constant speed (CS) control that is the current state of the art in clinical practice. Additionally, two treatment objectives were investigated to achieve pulsatility maximization and left ventricular stroke work (LVSW) minimization by implementing copulsation and counterpulsation pump modes, respectively. Under all experimental conditions, the PDD-ILC as well as the PF-PIDC demonstrated highly accurate tracking of the reference pump flow trajectories, outperforming existing model-based iterative learning control approaches. Additionally, the developed controllers achieved the predefined treatment objectives and resulted in improved hemodynamics and preload sensitivities compared to the CS support.
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Affiliation(s)
| | | | | | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
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5
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Adji A, Shehab S, Jain P, Robson D, Jansz P, Hayward CS. Arterial Compliance and Continuous-Flow Left Ventricular Assist Device Pump Function. ASAIO J 2022; 68:925-931. [PMID: 35544445 DOI: 10.1097/mat.0000000000001768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Durable continuous-flow left ventricular assist devices (cfLVADs) demonstrate superior survival, cardiac functional status, and overall quality of life compared to medical therapy alone in advanced heart failure. Previous studies have not considered the impact arterial compliance may have on pump performance or developed arterial pressure. This study assessed the impact of alterations in arterial compliance, preload, and afterload on continuous-flow pump function and measured hemodynamics using an in-vitro pulsatile mock circulatory loop. Decreased arterial compliance was associated with a significant increase in arterial pressure pulsatility which was not evident in the flow pulsatility, as displayed in pump flow waveforms. There were marked changes in the pump flow waveforms due to the significant alteration in the aortoventricular gradient during diastole according to the changes in compliance. This study demonstrates that changes in systemic blood pressure, afterload, and left ventricular contractility each significantly affects the flow waveform. The association of hypertension with lower aortic compliance results in markedly decreased diastolic flow rates which may be important in contributing to a greater risk of adverse events under cfLVAD support.
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Affiliation(s)
- Audrey Adji
- From the Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
- Mechanical Circulatory Support Laboratory, Victor Chang Cardiac Research Institute, Sydney, Australia
- St Vincent's Clinical School, UNSW Medicine and Health, Sydney, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Sajad Shehab
- Mechanical Circulatory Support Laboratory, Victor Chang Cardiac Research Institute, Sydney, Australia
| | - Pankaj Jain
- From the Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
| | - Desiree Robson
- From the Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
| | - Paul Jansz
- From the Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
- Mechanical Circulatory Support Laboratory, Victor Chang Cardiac Research Institute, Sydney, Australia
- St Vincent's Clinical School, UNSW Medicine and Health, Sydney, Australia
- School of Medicine, University of Notre Dame, Sydney, Australia
| | - Christopher S Hayward
- From the Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
- Mechanical Circulatory Support Laboratory, Victor Chang Cardiac Research Institute, Sydney, Australia
- St Vincent's Clinical School, UNSW Medicine and Health, Sydney, Australia
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Cysyk J, Jhun CS, Newswanger R, Pae W, Izer J, Flory H, Reibson J, Weiss W, Rosenberg G. In Vivo Evaluation of a Physiologic Control System for Rotary Blood Pumps Based on the Left Ventricular Pressure-Volume Loop. ASAIO J 2022; 68:791-799. [PMID: 34860709 PMCID: PMC9156658 DOI: 10.1097/mat.0000000000001619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Current generation continuous flow assist devices to operate at a fixed speed, which limits preload response and exercise capacity in left ventricular assist device (LVAD) patients. A feedback control system was developed to automatically adjust pump speed based on direct measurements of ventricular loading using a custom cannula tip with an integrated pressure sensor and volume-sensing conductance electrodes. The input to the control system is the integral of the left ventricular (LV) pressure versus conductance loop (PGA) over each cardiac cycle. The feedback control system adjusts pump speed based on the difference between the measured PGA and the desired PGA. The control system and cannula tip were tested in acute ovine studies (n = 5) using the HeartMate II LVAD. The preload response of the control system was evaluated by partially occluding and releasing the inferior vena cava using a vessel loop snare. The cannula tip was integrated onto a custom centrifugal flow LVAD and tested in a 14-day bovine study. The control system adjusted pump support to maintain constant ventricular loading: pump speed increased (decreased) following an increase (decrease) in preload. This study demonstrated in vivo the Starling-like response of an automatic pump control system based on direct measurements of LV loading.
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Affiliation(s)
- Joshua Cysyk
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - Choon-Sik Jhun
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - Ray Newswanger
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - Walter Pae
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - Jenelle Izer
- Department of Comparative Medicine, Penn State College of Medicine, Hershey, PA
| | - Heidi Flory
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - John Reibson
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - William Weiss
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
| | - Gerson Rosenberg
- From the *Department of Surgery, Penn State College of Medicine, Hershey, PA
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7
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Intelligent and strong robust CVS-LVAD control based on soft-actor-critic algorithm. Artif Intell Med 2022; 128:102308. [DOI: 10.1016/j.artmed.2022.102308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 02/26/2022] [Accepted: 04/16/2022] [Indexed: 11/23/2022]
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8
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Fetanat M, Stevens M, Hayward C, Lovell NH. A Sensorless Control System for an Implantable Heart Pump Using a Real-Time Deep Convolutional Neural Network. IEEE Trans Biomed Eng 2021; 68:3029-3038. [PMID: 33621164 DOI: 10.1109/tbme.2021.3061405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Left ventricular assist devices (LVADs) are mechanical pumps, which can be used to support heart failure (HF) patients as bridge to transplant and destination therapy. To automatically adjust the LVAD speed, a physiological control system needs to be designed to respond to variations of patient hemodynamics across a variety of clinical scenarios. These control systems require pressure feedback signals from the cardiovascular system. However, there are no suitable long-term implantable sensors available. In this study, a novel real-time deep convolutional neural network (CNN) for estimation of preload based on the LVAD flow was proposed. A new sensorless adaptive physiological control system for an LVAD pump was developed using the full dynamic form of model free adaptive control (FFDL-MFAC) and the proposed preload estimator to maintain the patient conditions in safe physiological ranges. The CNN model for preload estimation was trained and evaluated through 10-fold cross validation on 100 different patient conditions and the proposed sensorless control system was assessed on a new testing set of 30 different patient conditions across six different patient scenarios. The proposed preload estimator was extremely accurate with a correlation coefficient of 0.97, root mean squared error of 0.84 mmHg, reproducibility coefficient of 1.56 mmHg, coefficient of variation of 14.44%, and bias of 0.29 mmHg for the testing dataset. The results also indicate that the proposed sensorless physiological controller works similarly to the preload-based physiological control system for LVAD using measured preload to prevent ventricular suction and pulmonary congestion. This study shows that the LVADs can respond appropriately to changing patient states and physiological demands without the need for additional pressure or flow measurements.
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Jain P, Adji A, Emmanuel S, Robson D, Muthiah K, Macdonald PS, Hayward CS. Phenotyping of Stable Left Ventricular Assist Device Patients Using Noninvasive Pump Flow Responses to Acute Loading Transients. J Card Fail 2021; 27:642-650. [PMID: 33497807 DOI: 10.1016/j.cardfail.2021.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Although it has been established that continuous flow left ventricular assist devices are sensitive to loading conditions, the effect of acute load and postural changes on pump flow have not been explored systematically. METHODS AND RESULTS Fifteen stable outpatients were studied. Patients sequentially transitioned from the seated position to supine, passive leg raise, and standing with transition effects documented. A modified Valsalva maneuver, consisting of a forced expiration with an open glottis, was performed in each position. A sustained, 2-handed handgrip was performed in the supine position. The pump flow waveform was recorded continuously and left ventricular end-diastolic diameter measured during each stage using transthoracic echocardiography. Transitioning from seated to supine posture produced a significant increase in the flow and the ventricular end-diastolic diameter, consistent with an increased preload. The transition from supine to standing produced a transient increase in the mean flow and decreased the flow pulsatility index. At steady state, these changes were reversed with a decrease in the mean and trough flow and increased pulsatility index, consistent with venous redistribution and possible baroreflex compensation. Four distinct patterns of standing-induced flow waveform effects were identified, reflecting varying preload, afterload, and individual compensatory effects. A sustained handgrip produced a significant decrease in flow and increase in flow pulsatility across all patients, reflecting an increased afterload pressure. A modified Valsalva maneuver produced a decrease in the flow pulsatility while seated, supine, and standing, but not during leg raise. Five patterns of pulsatility effect during Valsalva were observed: (1) minimal change, (2) pulsatility recovery, (3) rapid flatline, (4) slow flatline with delayed flow recovery, and (5) primary suction. CONCLUSIONS Acute disturbances in loading conditions produce heterogeneous pump flow responses reflecting their complex interactions with pump and ventricular function as well as reflex compensatory mechanisms. Differences in responses and individual variabilities have significant implications for automated pump control algorithms.
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Affiliation(s)
- Pankaj Jain
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia; University of New South Wales, Sydney, Australia
| | - Audrey Adji
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
| | - Sam Emmanuel
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia; University of New South Wales, Sydney, Australia
| | - Desiree Robson
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
| | - Kavitha Muthiah
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia
| | - Peter S Macdonald
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia; University of New South Wales, Sydney, Australia; Victor Chang Cardiac Research Institute, Sydney, Australia
| | - Christopher S Hayward
- Heart Failure and Transplant Unit, Cardiology Department, St Vincent's Hospital, Sydney, Australia; University of New South Wales, Sydney, Australia; Victor Chang Cardiac Research Institute, Sydney, Australia.
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Shi Y, Yang H. Mock circulatory test rigs for the in vitro testing of artificial cardiovascular organs. J Med Eng Technol 2019; 43:223-234. [PMID: 31464556 DOI: 10.1080/03091902.2019.1653390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In vitro study plays an important role in the experimental study of cardiovascular dynamics. An essential hardware facility that mimics the blood flow changes and provides the required test conditions, a mock circulatory test rig (MCTR), is imperative for the execution of in vitro study. This paper examines the current MCTRs in use for the testing of artificial cardiovascular organs. Various aspects of the MCTRs are surveyed, including the necessity of in vitro study, the building of MCTRs, relevant standards, general system structure (e.g., the motion and driving, fluid, measurement subsystems), classification, motion driving mechanism of MCTRs, and the considerations for the modelling of the physiological impedance of MCTRs. Examples of the steady and pulsatile flow types of the MCTRs are introduced. Recent developments in MCTRs are inspected and possible future design improvements suggested. This study will help researchers in the design, construction, analysis, and selection of MCTRs for cardiovascular research.
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Affiliation(s)
- Yubing Shi
- College of Medical Technology, Shaanxi University of Chinese Medicine , Xianyang , PR China
| | - Hongyi Yang
- College of Medical Technology, Shaanxi University of Chinese Medicine , Xianyang , PR China
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11
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Fetanat M, Stevens M, Hayward C, Lovell NH. A Physiological Control System for an Implantable Heart Pump That Accommodates for Interpatient and Intrapatient Variations. IEEE Trans Biomed Eng 2019; 67:1167-1175. [PMID: 31380742 DOI: 10.1109/tbme.2019.2932233] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Left ventricular assist devices (LVADs) can provide mechanical support for a failing heart as a bridge to transplant and destination therapy. Physiological control systems for LVADs should be designed to respond to changes in hemodynamic across a variety of clinical scenarios and patients by automatically adjusting the heart pump speed. In this study, a novel adaptive physiological control system for an implantable heart pump was developed to respond to interpatient and intrapatient variations to maintain the left-ventricle-end-diastolic-pressure (LVEDP) in the normal range of 3 to 15 mmHg to prevent ventricle suction and pulmonary congestion. A new algorithm was also developed to detect LVEDP from pressure sensor measurement in real-time mode. Model-free adaptive control (MFAC) was employed to control the pump speed via simulation of 100 different patient conditions in each of six different patient scenarios, and compared to standard PID control. Controller performance was tracked using the sum of the absolute error (SAE) between the desired and measured LVEDP. The lower SAE on control tracking performance means that the measured LVEDP follows the desired LVEDP faster and with less amplitude oscillations, preventing ventricle suction and pulmonary congestion (mean and standard deviation of SAE (mmHg) for all 600 simulations were 18813 ± 29345 and 24794 ± 28380 corresponding to MFAC and PID controller, respectively). In four out of six patient scenarios, MFAC control tracking performance was better than the PID controller. This study shows the control performance can be guaranteed across different patients and conditions when using MFAC over PID control, which is a step toward clinical acceptance of these systems.
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12
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Huang F, Gou Z, Fu Y. Preliminary evaluation of a predictive controller for a rotary blood pump based on pulmonary oxygen gas exchange. Proc Inst Mech Eng H 2019; 233:267-278. [PMID: 30760162 DOI: 10.1177/0954411918823035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Physiological control of rotary blood pumps is becoming increasingly necessary for clinical use. In this study, the mean oxygen partial pressure in the upper airway was first quantitatively evaluated as a control objective for a rotary blood pump. A model-free predictive controller was designed based on this control objective. Then, the quantitative evaluation of the controller was implemented with a rotary blood pump model on a complete cardiovascular model incorporated with airway mechanics and gas exchange models. The results show that the controller maintained a mean oxygen partial pressure at a normal and constant level of 138 mmHg in the left heart failure condition and restored basic haemodynamics of blood circulation. A left ventricular contractility recovery condition was also replicated to assess the response of the controller, and a stable result was obtained. This study indicates the potential use of the oxygen partial pressure index during pulmonary gas exchange when developing a multi-objective physiological controller for rotary blood pumps.
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Affiliation(s)
- Feng Huang
- 1 College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou, China.,2 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
| | - Zhe Gou
- 2 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
| | - Yang Fu
- 3 School of Mechanical and Automotive Engineering, Zhejiang University of Science and Technology, Hangzhou, China
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Shi Y, Korakianitis T, Li Z, Shi Y. Structure and motion design of a mock circulatory test rig. J Med Eng Technol 2018; 42:443-452. [PMID: 30499728 DOI: 10.1080/03091902.2018.1543467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mock circulatory test rig (MCTR) is the essential and indispensable facility in the cardiovascular in vitro studies. The system configuration and the motion profile of the MCTR design directly influence the validity, precision, and accuracy of the experimental data collected. Previous studies gave the schematic but never describe the structure and motion design details of the MCTRs used, which makes comparison of the experimental data reported by different research groups plausible but not fully convincing. This article presents the detailed structure and motion design of a sophisticated MCTR system, and examines the important issues such as the determination of the ventricular motion waveform, modelling of the physiological impedance, etc., in the MCTR designing. The study demonstrates the overall design procedures from the system conception, cardiac model devising, motion planning, to the motor and accessories selection. This can be used as a reference to aid researchers in the design and construction of their own in-house MCTRs for cardiovascular studies.
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Affiliation(s)
- Yuhui Shi
- a Northwest Institute of Mechanical and Electrical Engineering , Xianyang , Shaanxi Province , China
| | - Theodosios Korakianitis
- b Parks College of Engineering, Aviation and Technology , Saint Louis University , Saint Louis , MO , USA
| | - Zhongjian Li
- c College of Automation , Northwestern Polytechnical University , Xi'an , China
| | - Yubing Shi
- d Faculty of Arts, Science and Technology , University of Northampton , Northampton , UK
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