Abstract 2165: Harvesting the Energy of Cardiac Motion to Power a Pacemaker
There is significant motion of the heart with each cardiac cycle. We examine the feasibility of harvesting surplus energy (HE) using a catheter-mounted device (CMD) that could be incorporated into a pacemaker/ICD lead and assist powering. The CMD consisted of a pacemaker electrode incorporating a coaxially mounted device with 2 pressure responsive bladders that utilise cardiac pressure (RV/RA) to drive a linear generator. CMD was placed at the RVA of an anesthetized pig (Landrace, 45kg) via the internal jugular vein. Arterial and RV pressure were recorded. The energy generated by the device was continuously monitored using a portable data acquisition system during steady state and then during induced tachycardia (isoproterenol), bradycardia (adenosine) and hypotension (pentobarbital). Placement of the device was uncomplicated. The figure⇓ illustrates the effect of 4 mcg isoproterenol on HE from device. In steady state (80 bpm, BP 100/60) the energy generated by each cardiac cycle was 4.3μJ (variance ± 0.8μJ). Incremental changes in heart rate produced a corresponding increase in HE e.g. 104 to 128 bpm produced 140% increase in HE (10.0μJ). Relative bradycardia/hypotension following adenosine/pentobarbitol administration produced a proportionate decrease in HE. Post mortem examination demonstrated no significant endocardial trauma. This study has demonstrated the feasibility of energy harvesting of cardiac motion. The device produced 17% of the energy required to power a conventional pacemaker. With further material modification it is envisaged that HE will be efficient enough to allow for complete and indefinite powering of pacemakers.