October 24, 2007 Despite being sensitive instruments, blood pressure meters are often carried around in doctors’ coat pockets and as a result they're exposed to being bumped or dropped. Because they contain very fine mechanisms that react sensitively to any form of shock this causes them to produce false readings without the doctor necessarily noticing the problem, in turn leading to disastrous effects on patients’ treatment, as drug doses may have to be changed if the blood pressure exceeds a certain value. This new pressure meter, created by the Rudolf Riester company and researchers at the Fraunhofer Technology Development Group TEG in Stuttgart, employs a delicate damping system to protect the integrity of the meter.
The padding dampens any potential impact and protects the mechanical parts against shock. “We used a high-speed camera to film what happens when a blood pressure meter suffers a heavy blow,” explains TEG project manager Andreas Reindl. “The parts bang into each other and are shaken violently.” The recordings, taken at 2000 frames per second, provided conclusive evidence that the indicator, too, is sometimes affected. The films allowed the engineers to determine which areas of the device required padding, and developed a substantial cushioning element which they refer to as a ‘damping lip’. The most important pre-condition is that the overall construction should remain airtight, otherwise the air pressure will drop and this, too, will cause false readings.
The damping system in the shock-proof blood pressure meter ensures that readings are never out by more than 2 mmHg. Testing on regular systems has shown they can often be out by a margin of 10 mmHg which could have a big impact on treatment prescribed by a doctor. The team behind the development of the shock-proof meter will present details of their new product at the World Forum for Medicine in Germany this November.