Abstract
An implantable telemetry epidural pressure sensor has been developed to monitor the intracranial pressure (ICP) after an operation in the field of cerebro-surgery. This sensor is embedded under the scalp to measure the intracranial pressure on dura mater.
This sensor has microbatteries, operates on FM-FM active telemetry using a semiconductor pressure sensor at the pressure receiving area. A subcarrier of 24kHz and the main carrier on 80MHz band are generated on both surfaces of a 14mm dia. alumina substrate. The power unit has two microbatteries. A reed switch installed at the top of the sensor is operated by an external magnetic field only when a monitoring. An antenna is embedded under the scalp to allow contact with the body.
Experiments on dogs and 8 cases of clinical applications were made and realized measurement of ICP with nonrestriction.
