Introducing a hardware-in-the-loop simulation of the cardiovascular system

Abstract

Advances in direct mechanical ventricular actuation devices have been limited by the inability to test the whole device interaction in-vitro. In this study, we introduce a novel technique to produce a realistic, multimodality cardiovascular simulator to mimic the activity of a beating heart. To achieve the mechanical representation of the heart, each ventricle was defined by a real-time modifiable semicircular pattern of post-buckled spring steel strips with adjustable boundary attachments. The mechanical properties of these strips such as stiffness, length, width and boundary conditions approximated the local and global biomechanical properties of the native heart. This physical heart model interfaced with a mathematical model of the cardiovascular system based on hardware-in-the-loop simulation. In-vitro experiments were carried out in an attempt to investigate into the effect that the DMVA system has on PV loop, cardiac output, and overall hemodynamics under different physiological conditions. By employing this in-vitro setting, assist devices can be physically applied to the circulatory models and assessed before animal or clinical trials are conducted. This will significantly aid device behavioural understanding, development time and cost during device's prototyping.

Mock circulatory loops used for testing cardiac assist devices: A review of computational and experimental models

“…Others have developed an H-MCL to test cardiac compression devices; an apparatus that wraps around the heart to provide beating assistance. 108,109 The physical part of the H-MCL, mechanical ventricles, interacted with a numerical model of the CVS. The contraction of the CAD is measured with a force sensor, which is used as input to the numerical model.…”

A Hybrid Experimental-Computational Modeling Framework for Cardiovascular Device Testing

“…Pillon et al first suggested the HIL approach for cardiovascular modeling in 1992 [14]. Later, Hanson et al [15] and Alazmani et al [16] each constructed an HIL model containing a ventricle-mimicking actuator setup controlled based on the desired pressures calculated in real-time from a simple numerical lumped-parameter simulation. Nestler et al [17] used a hybrid mock loop to create a feedback environment for testing rotary ventricular assist devices under steady flow conditions.…”

Diseño de una plataforma de prueba de sensores virtuales para el sistema glucosa-insulina de pacientes UCI usando la técnica HIL

“…El uso de este tipo de técnicas ha ido tomando fuerza en el área cardiaca debido a los limitantes que representa probar la interacción de los dispositivos médicos en vivo. En el 2009 se desarrolló un entorno de simulación para sistemas fisiológicos cardiovasculares, el cual relacionaba un modelo físico del corazón con un modelo matemático del sistema cardiovascular, que permitía evaluar el comportamiento realista de un corazón latiente a diferentes condiciones fisiológicas, evaluando así el dispositivo de asistencia cardiaca en una etapa previa a las evaluaciones clínicas y en animales [4]. Durante el 2015 se implementó HIL con el fin de evaluar la energía consumida por un marcapaso cardiaco cuando este se enfrenta a diferentes patologías [5].…”