Sensor in Artery Measures Blood Pressure

Photo: Sensor on a finger tip

A flow of information running under
the skin via a tiny sensor;
© Fraunhofer IMS

If a person’s blood flows through their arteries at too high a pressure, even when they are lying still on the sofa, they could be in danger. High blood pressure causes the heart to constantly pump at full speed, which strains both the heart and vessel walls.

Drugs can provide relief, but in many cases the patient’s blood pressure is still difficult to regulate and has to be consistently monitored over a long period of time. Therefore, patients have to wear a small case containing the blood pressure meter close to their body. An inflatable sleeve on their arm records their blood pressure values, for which it is regularly pumped up and deflated. This is a burden on the patients, particularly at night. The whole process could now become easier with an implant that could replace the current method.

“A doctor introduces the pressure sensor directly into the femoral artery in the groin,” explains Hoc Khiem Trieu of the Fraunhofer Institute. “The sensor, which has a diameter of about one millimetre including its casing, measures the patient’s blood pressure 30 times per second. It is connected via a flexible micro-cable to a transponder unit, which is likewise implanted in the groin under the skin. This unit digitises and encodes the data coming from the micro-sensor and transmits them to an external reading device that patients can wear like a cell phone on their belt. From there, the readings can be forwarded to a monitoring station and analysed by the doctor.”

Because the researchers use special components in CMOS technology, the system requires little energy. The micro-implants can be supplied with electricity wirelessly via coils. The researchers are currently performing the first clinical trials.

MEDICA.de; Source: Fraunhofer-Gesellschaft