Super-capacitors for implantable medical devices with wireless power transmission

Abstract

Patients using implantable devices with wireless power transmission (such as inductive telemetry) as the energy source are required to carry external hardware and antennas on their body continuously during the monitoring period. This discomfort can be reduced by integrating tiny super-capacitors as an energy source for the device. The external wireless telemetry unit used to activate and interrogate the implantable device charges the super capacitors integrated on it. When the wireless telemetry unit is removed, the super capacitor powers the implantable device. This paper shows the benefits of integrating super capacitors onto an existing pressure sensing medical implant that utilises an inductive telemetry link. Test results show that the implant can be powered for a full day using an 88 mF super capacitor. This super capacitor can be fully charged using the inductive telemetry link at a wireless distance of 20 cm in 81 seconds.