A left heart ventricle simulator manufactured by 3D printing

Abstract

Mechanical circulatory assistance devices have been researched and used to assist the pumping function of the failing heart. Examples of these devices are intra-aortic balloon pumps (IABP) and ventricular assist devices (VAD). In order to perform the in vitro tests of these devices, before the in vivo tests, cardiovascular simulators are required. One important part of a cardiovascular simulator is the simulation of the left ventricle which is a pulsatile blood pump. Most of the existing left ventricle simulators use pneumatic actuator. This type of actuator creates negative pressure inside the ventricle chamber which is not physiological. The objective of this work is to develop a pulsatile pump that simulates the left ventricle without creating negative pressure. The concept of the pulsatile pump was evaluated using 3D printing to manufacture the prototype. The developed pulsatile pump is composed of two reservoirs: a rigid one with 5.0 x 10 4 mm 3 of volume which corresponds to the residual systolic volume and a flexible one which ejects 8.0 x 10 4 mm 3 of fluid per beating cycle when compressed by a platform. Two caged-ball valves simulating the mitral and the aortic valve are responsible for the unidirectional flow. A constant pressure of 1,333 Pa inside an open reservoir maintains the fluid flowing into the pulsatile pump through the mitral valve. A DC motor is connected to a lever mechanism that transforms the rotational movement of the motor into vertical movement of the platform. The vertical movement of the platform is responsible for the pulsatile flow of the pump, generating a pressure of 10,640 to 15,960 Pa at the outlet of the pump. Since the platform is not attached to the flexible reservoir, there is no generation of the negative pressure inside the simulator.