Wireless Power Supply for ICP Devices With Hybrid Supercapacitor and Battery Storage

Hydrocephalus patients use a shunt to drain excess fluid from the brain, however, these shunts fail regularly. The most valuable shunt diagnostic tool would be a pressure sensor implanted in the brain. This paper presents a wireless power transfer system being able to support the measurement of intracranial pressure (ICP) for a lifetime operation. A rechargeable battery is complemented by a new energy storage element-an electric double-layer capacitor to form a hybrid energy storage system, and a dynamic energy management algorithm is developed to control the power delivery. The charging circuitry for the hybrid system is founded on using the inductive power transfer technology, and the energy management scheme schedules the flow to power the ICP device automatically to meet both short-and long-term operation requirements. The voltage levels of the supercapacitor and rechargeable battery are continuously monitored, and the experimental results demonstrate that it takes only 3 seconds to charge up the supercapacitor for 1-minute operation of ICP for quick data collection, while longer durations of monitoring can be supported by the battery.