An implant now under development could include a blood pressure sensor, about 1-mm dia. including its casing, that takes measurements about 30 times per sec. “A doctor would introduce the pressure sensor directly into the femoral artery in the groin,” says Hoc Khiem Trieu of the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg, Germany. The sensor is connected by flexible microcable to an implanted transponder. The transponder digitizes and encodes data coming from the microsensor and transmits it to an external reading device that a patient can wear like a cell phone on his belt. From there, readings are forwarded to a monitoring station and analyzed by the doctor.” The sensor uses little energy. The microimplants can be supplied with electricity — wirelessly — via coils.

Researchers are currently performing first clinical trials. The device would be useful for monitoring the heartbeat of those for whom drugs alone do not control high blood pressure. Current monitors require the patient to wear an inflatable sleeve on the arm to record blood-pressure values. The sleeve is regularly pumped up and deflated. This is bothersome, especially at night while attempting to sleep. The whole process may become easier because of a tiny implant that could replace the current method.