New Blood Pressure Guardian "sits" in the Artery

Sensor in artery performs 30 measurements per second

The tiny pressure sensor - pictured here on a finger - measures the blood pressure directly in the inguinal artery. © Fraunhofer IMS
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High blood pressure can put a patience on doctors and patients: Often, blood pressure needs to be monitored for a longer period of time before it settles. A new pressure sensor could greatly simplify this in the future. It is inserted into the inguinal artery and transmits the data wirelessly.

If the blood flows through the arteries with too much pressure, even if the human is lying quietly on the sofa, this can be dangerous: In high blood pressure, the heart is constantly pumping at full speed, which burdens both heart and vessel walls. Medications should help.

Nevertheless, many patients find it difficult to adjust their blood pressure - they need to be consistently monitored over a longer period of time. An annoying procedure: The patients carry a small box in which the blood pressure monitor is located on the body. An inflatable cuff on the arm records the current blood pressure values. This cuff is inflated and deflated at regular intervals, which puts a strain on the patients, especially at night.

30 measurements - per second

In the future, this should be simpler: A tiny implant developed by Fraunhofer researchers together with partners in a BMBF-funded project could replace the previous procedure. "A doctor introduces the pressure sensor directly into the inguinal artery, " explains Hoc Khiem Trieu from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg.

"The sensor, which has a diameter of about one millimeter, including encapsulation, measures blood pressure 30 times a second. A flexible micro cable connects the sensor to a transponder unit, which is also located in the groin under the skin. It digitizes and encodes the data from the microsensor and then transmits it to the external reader, which the patient can wear like a cell phone on his belt. From there, the values ​​can be transferred to a monitoring station where the physician evaluates them ", the Fraunhofer researcher continues. display

Low energy consumption

Because the scientists use special components in CMOS technology, the system requires little energy: the micro-implants can be powered by coils wirelessly powered.

Implantable pressure sensors are also suitable for other applications, such as the monitoring of patients suffering from cardiac insufficiency. The researchers are currently conducting initial tests.

(idw - Fraunhofer-Gesellschaft, 07.01.2009 - DLO)