A Telemetric Pressure Sensor System for Biomedical Applications

A new implantable pressure sensor for long-term monitoring of intracranial pressure is presented. The sensor is powered by telemetry and can be interrogated wirelessly. A capacitive pressure transducer, whose capacitance is converted to a frequency-encoded signal by an application-specific integrated circuit (ASIC), senses the absolute pressure. The pressure-encoded signal, the ASIC input voltage, and onboard calibration parameters are transmitted to an external reading unit. The proposed novel packaging solution is designed for long-term stability and reliability of the sensor. The accuracy of sensor at body temperature is better than 2 mbar across a pressure range of 600-1200 mbar. The sensor is 13 mm in diameter and 4.5 mm in height.