Parameter optimization and validation of a cost efficient hybrid mock loop of the cardiovascular system

Salesch, Tobias; Gesenhues, Jonas; Habigt, Moriz; Mechelinck, Mare; Hein, Marc; Abel, Dirk

doi:10.23919/ecc54610.2021.9654952

Cited by 3 publications

(3 citation statements)

References 15 publications

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“…SVR case is achieved in close to the other studies with the standard deviation of 1703.3 AE 370.18 dyn s/cm 5 . For the mean aortic resistance, only Salesch et al [28] reported scalar value with the difference of 10.18 dyn s/cm 5 . Systemic and aortic resistances depend on the mechanical component and manual valve which are different from the proposed hMCL.…”

Section: Discussionmentioning

confidence: 99%

“…The mechanical tank used in the hMCL device does not adequately capture the low-capacitance values observed in the human body. Consequently, the volume change of the Frank-Starling Mechanism (FSM) fails to track the reference LVP and AOP signals [28,31]. To address this limitation, a new volume-elastance equation is proposed that incorporates both the LVV and the capacitance value of the LV gas chamber.…”

Section: A New Volume-elastance Equationmentioning

confidence: 99%

“…However, repeatability was problematic for validating their results due to the absence of controlled dynamics. Salesch et al [28] developed a closed-circuit hMCL to replicate the physiological behavior of the CVS. They controlled both aortic and left ventricular pressures but did not guarantee stability.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A New Cardiovascular Mock Loop Driven by Novel Active Capacitance in Normal and Abnormal Conditions

Iscan,

Yesildirek

2023

Applied Bionics and Biomechanics

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The hybrid mock circulatory loop (hMCL) serves as a crucial hemodynamic simulation tool, offering exceptional flexibility, controllability, and reproducibility for investigating the mechanisms underlying cardiovascular diseases (CVD) in a controlled environment, circumventing the limitations of live organism studies. This paper introduces a novel design and control strategy for hMCL, introducing a novel left ventricle volume–elastance (LVVE) equation that unifies the autoregulation of the Frank–Starling mechanism (FSM) with left ventricle contractility (LVC). LVVE establishes a dynamic link between left ventricular volume (LVV) and LVC, inherently satisfying the regulatory relationship between left ventricular pressure (LVP) and LVV through a mathematical equation. For the first time, LVVE integration significantly enhances the physiological relevance of hMCL by faithfully replicating FSM responses across diverse conditions, including aortic stenosis (AS), variations in systemic vascular resistance (SVR), and heart rate (HR) variations. Furthermore, this study introduces the stability proofs for the discrete closed-loop hMCL, enabling real-time proportional valve control through discrete feedback linearization—an innovative departure from conventional methods. Notably, FSM emulation is achieved by tracking reference maximum and minimum LVV values, eliminating the reliance on predefined functions or existing data, such as the maximum LV elastance value. Rigorous experimental validation, encompassing numerical simulations and comparative analyses with prior research, attests to the precision and efficacy of the proposed hMCL in faithfully replicating both normal and abnormal CV conditions. Significantly, the hMCL demonstrates that increasing HR enhances LVC while maintaining physiological pressures; however, this increase in LVC corresponds with a decrease in LVV, in alignment with human data and FSM principles. Crucially, the coupling mechanism between the FSM and LVC yields results of enhanced physiological fidelity, significantly advancing the hMCL’s utility in physiological research. Moreover, the hMCL’s capacity to simulate critical cardiovascular scenarios, including AS, SVR fluctuations, and HR variations, underscores its versatility and substantial potential for investigating complex CV dynamics.

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Section: Discussionmentioning

confidence: 99%

Section: A New Volume-elastance Equationmentioning

confidence: 99%

See 1 more Smart Citation

A New Cardiovascular Mock Loop Driven by Novel Active Capacitance in Normal and Abnormal Conditions

Iscan,

Yesildirek

2023

Applied Bionics and Biomechanics

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Nonlinear control of a hybrid pneumo‐hydraulic mock circuit of the cardiovascular system

Alhajyounis,

Aydoğan,

Canbaş

et al. 2024

Intl J Robust & Nonlinear

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Hybrid cardiovascular mock circuits (HMC), designed for dynamic testing of Ventricular Assist Devices (VAD), offer physiologic accuracy by sequestering model complexity in silico and ease of construction by reducing number of model elements in vitro. Despite superior response time and precision, pneumatic actuation is avoided in HMCs due to nonlinear dynamics and noise. We tested the hypothesis that a HMC consisting of a variable elastance‐driven numerical cardiovascular circuit (CVS) coupled to a pneumo‐hydraulic physical circuit can be controlled without linearizing system dynamics. Reference left ventricular and aortic pressures were generated in silico in a seventh‐order electrical analogue of the CVS and transmitted via an electro‐hydraulic interface to the physical circuit. There, they were tracked in in vitro preload and afterload pneumo‐hydraulic reservoirs, respectively. The nonlinear pneumatic dynamics in the reservoirs was controlled using the Lyapunov stability criterion. A centrifugal pump, the speed (i.e., flow) of which was adjusted manually or using PID control, was interposed between the reservoirs and mimicked the VAD under evaluation. The flow of a recirculating gear pump was controlled by an integral backstepping method to equalize reservoir fluid volumes by rejecting pressure and flow disturbances. Sensor noise was reduced with discrete‐time Kalman filtering. Our results showed that normal, failing, and assisted cardiovascular physiologies simulated in silico were commensurate with clinical data obtained from subjects with similar pathologies. The numerical pressure references were tracked with high accuracy at the physical VAD terminals. Reservoir volumes remained stable at various combinations of heart rate, pressure, and VAD flow for prolonged durations with negligible steady‐state error. The HMC described here offers a stable performance testing platform for VAD prototypes.

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A Protocol for Coupling Volumetrically Dynamic In-Vitro Experiments to Numerical Physiology Simulation for a Hybrid Cardiovascular Model

Umo

Kung

2023

IEEE Trans. Biomed. Eng.

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Parameter optimization and validation of a cost efficient hybrid mock loop of the cardiovascular system

Cited by 3 publications

References 15 publications

A New Cardiovascular Mock Loop Driven by Novel Active Capacitance in Normal and Abnormal Conditions

A New Cardiovascular Mock Loop Driven by Novel Active Capacitance in Normal and Abnormal Conditions

Nonlinear control of a hybrid pneumo‐hydraulic mock circuit of the cardiovascular system

A Protocol for Coupling Volumetrically Dynamic In-Vitro Experiments to Numerical Physiology Simulation for a Hybrid Cardiovascular Model

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