Design and simulation of an energy harvester utilizes blood pressure variation inside superior vena cava

摘要

Pacemaker is a vital electronic medical device that manages the abnormal heart rhythm. One of the technical problems that pacemaker suffers from is its power source which is a lithium-ion battery with short life compared to patient life. So, this work is concerned with designing and simulation of a novel way to harvest energy from pulsatile pressure inside superior vena cava (SVC) to recharge pacemaker battery. The working principle depends on covering the pacemaker lead (which is a wire inserted through SVC during pacemaker implantation surgery) with a layer of polydimethylsiloxane (PDMS) and creates some cavities in this layer. These cavities would be covered with a thin diaphragm of PDMS which will be in contact with pulsatile blood pressure inside SVC. Under this diaphragm, there will be a lead zirconate titanate (PZT) layer with an area of 2.5 × 6 mm^{2 and thickness of 0.028 mm working as a cantilever that is fixed in cavity wall from one side and free from other side. When the pressure varies inside SVC in a harmonic manner, the PDMS diaphragm deflects up and down causing the PZT layer to deform and hence generate pulsations of electricity for each heartbeat. The harvesting process was simulated and showed that power of 52 nW could be harvested for each cavity which could be used to recharge the pacemaker battery and avoid replacing it.}