Sensor records blood pressure continuously

Measurement is carried out by several sensors which simultaneously measure the contact pressure, pulse and blood flow on the surface of the skin in the vicinity of the wrist. Michael Tschudin, STBL's cofounder, said: "This device can be used for medical purposes, for example as a precaution for high risk patients or for treating high blood pressure, but also as a blood pressure and heart rate monitor for leisure activities and sports as well as for monitoring fitness in high level sports." One obstacle which had to be overcome was that the pressure of the device on the skin changes constantly, requiring highly sensitive correctional measurements. The solution was using a sensor made from piezoresistive fibres in the wristband to measure the contact pressure of the device on the skin. The sensor – developed by Empa's Laboratory for High Performance Ceramics – registers such changes as slippage or muscle tension and corrects for them. The electrically conductive fibre detects movement or change in pressure, converts this into an electrical signal and transmits it to the measuring device. According to STBL, this increases measuring accuracy by more than 70%. Clinical trials of the device are underway and results are said to be 'promising'. The product is likely to be available in two versions: a medical monitoring device; and a version for leisure use.