Inductively Powered Pressure Sensing System Integrating a Far-Field Data Transmitter for Monitoring of Intracranial Pressure

Monitoring of intracranial pressure (ICP) provides a life-saving diagnostic tool. We present a battery-free pressure sensing system for minimally invasive ICP monitoring. It comprises a cranially concealed wireless pressure sensor and on- and off-body external units. The sensor is based on a piezoresistive element and is inductively powered through an on-body unit. It is also equipped with a far-field antenna, which conveys the pressure data to the off-body unit. We present the electromagnetic modeling of the system and report results from experiments carried out in a setting, which mimics the biological operation environment. The simulation and measurement results demonstrate the wireless pressure monitoring at a distance up to one meter over the pressure range from -3 to 33 mmHg and assess the impact of an imperfectly aligned inductive link on the operation of the system.