Design of mechanical arterial simulator

Abstract

A force controlled ultrasound probe is being explored as a new method of measuring blood pressure. An arterial simulator was designed and built for experiments. For this simulator, the vessels and bulk material were designed to meet the specifications of literature values of the physical dimensions and elastic modulus of carotid and brachial arteries and bulk surrounding the arteries. This was done through the use of a PVA cyrogel and Thermo rubber- mineral oil solution as the materials for the vessel and bulk material respectively. The concentration of the ingredients and the number of freeze thaw cycle of the cyrogel control the elasticity of the two materials. Custom molds were fabricated to the desired physical dimensions. Upon integration of the vessel and bulk, the vessel was connected to a network of hoses and a pump. The pump is a diaphragm pump whose volume/stroke and speed can be independently controlled to simulate the pulsing of a real human heart. Measurements were taken of the force applied to the probe for static pressures to demonstrate the force varying linearly with pressure. Further measurements were taken with fluid flowing through the vessel at various probe heights to demonstrate how force and thus pressure vary with height and to demonstrate that the probe can detect the waveforms that result from the vessels pulsing with each stroke of the diaphragm pump.