Fully implantable blood pressure sensor for hypertonic patients

In Germany approximately ten million people suffer from high blood pressure. About 1% of these patients can hardly be stabilized on drugs and a long time monitoring is advisable. A system consisting of an implant and an external reader station is presented to realize a long term monitoring for these patients. The implant consists of a newly designed sensor chip integrated at the head of a catheter (Oslash 1.1 mm) and a telemetric unit. The sensor-tip is placed into the femoral artery while the telemetric unit is implanted into the subcutaneous tissue. Thus the disturbance inside the blood vessel and the distance for wireless communication are kept as small as possible to obtain optimal parameters. The implant is supplied with energy wirelessly via inductive coupling from the external reader station. Data is readout from the external station with approx. 30 Hz and an overall accuracy of plusmn 2 mbar.