A mock circulation model for cardiovascular device evaluation

Abstract

The aim of this study was to develop an integrated mock circulation system that functions in a physiological manner for testing cardiovascular devices under well-controlled circumstances. In contrast to previously reported mock loops, the model includes a systemic, pulmonary, and coronary circulation, an elaborate heart contraction model, and a realistic heart rate control model. The behavior of the presented system was tested in response to changes in left ventricular contractile states, loading conditions, and heart rate. For validation purposes, generated hemodynamic parameters and responses were compared to literature. The model was implemented in a servo-motor driven mock loop, together with a relatively simple lead-lag controller. The pressure and flow signals measured closely mimicked human pressure under both physiological and pathological conditions. In addition, the system's response to changes in preload, afterload, and heart rate indicate a proper implementation of the incorporated feedback mechanisms (frequency and cardiac function control). Therefore, the presented mock circulation allows for generic in vitro testing of cardiovascular devices under well-controlled circumstances.

Design, Analysis and Testing of a Novel Mitral Valve for Transcatheter Implantation

“…A high peak in the initial diastolic transmitral pressure drop is measured in the tests (up to 45 mmHg). This is often observed in tests performed on hydro-mechanical pulse duplicators,16,28,29,48,53,55 and could be due to the non-physiological ventricular compliance, which may determine steeper flow waves and higher pressure gradients associated with early passive filling during ventricular relaxation. The calculated EOA well reflected the variation in the area of the implantation annulus, varying proportionally.…”

Inter-Technique Consistency and Prognostic Value of Intra-Procedural Angiographic and Echocardiographic Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Implantation

“…Recently, Miyazaki et al and Abdelghani et al, in an experimental study, reported excellent agreement between VD and regurgitation fraction evaluated in an in vitro setting. 11,12,21,22 Therefore, VD assessment (LVOT-AR) may play a central role in TAVI procedural guidance in the context of the minimalist TAVI approach. We believe that this intra-procedural direct comparison between the 2 modalities would facilitate the adoption of VD assessment into clinical practice.…”

Arduino control of a pulsatile flow rig

“…To simulate physiologically realistic pulsatile flow, a dedicated pumping system is used in these experiments. This can either be a mock loop representing the full circulatory system [8,9], or a pump that reproduces a waveform measured locally in-vivo [4,5,6,7,12].…”