HYBRID MECHANICAL CIRCULATORY LOOPS – AN EMERGING NEED FOR TOTAL ARTIFICIAL HEARTS WITH NOVEL TECHNOLOGIES.

Abstract

Circulatory assist devices need to be tested at various levels prior to human implantation. These include numerical simulations, lab and animal testing, tissue computability prior to human trials that would scale in terms of complexity of indications and participant load. Mock circulatory loops though not ideal offer the best current equivalents of gold standard for such purposes in the in vitro domain. These could be very simple hydraulic loops to complex hydraulic loop interface with computers. These need to replicate both right and left circulatory systems coupled with vascular compliances and resistances. It should recreate the perfusion rates and pressures that exist in normal systemic and pulmonary vasculature for both normal and heart failure models. These rigs greatly reduce the device evaluation costs by mimicking nature though vasomotor responses in the normal human body may require complicated evaluation models to be deciphered in future by use of evolving technologies. Following mechanical evaluation on the mock circulatory loop actual animal testing would give the experimental proof of concept. The basic requirements are that of a pump, ow channels, compliance chambers with monitoring of pressure and resistance changes using pressure and ow sensors. It serves as a safe low cost training and evaluating platform. Virtual mock loop simulation tool can simulate the hemodynamics using a lumped-parameter model for systemic/pulmonary circulation characteristic inputs values for impedance, systolic and diastolic ventricular compliance, beat rate, and blood volume and characteristics of the cardiac chambers and valves. VML contains several different lumped parameter models for selection and evaluation. It also stores and organizes data from different origins that makes comparison easier. For new total articial heart models the advantage of a dual approach emerges with use of hybrid mechanical circulatory loop.