Plessey Has Designed Handheld ECG Monitor

Plessey has designed its contactless electric field sensor, dubbed EPIC, in to a hand held ECG monitor which it will launch at next month's Electronica exhibition in Germany.

The UK-based firm has gone into the medical terminal business to commercialise its semiconductor sensor technology which requires no physical or resistive contact to make measurements.

"We are constantly being asked for products based on EPIC so we have designed our own that we now have available," said Barry Dennington, Plessey's COO.

Plessey started sampling its Electric Potential Integrated Circuit (EPIC) sensors a year ago.

"We have commercialised this sensor technology from lab prototype to volume production of ICs in just over a year," said Dennington.

The EPIC sensor measures changes in an electric field in a similar way to a magnetometer detecting changes in a magnetic field.

The technology works at normal room temperatures and functions as an ultra-high, input impedance sensor that acts as a highly stable, extremely sensitive, contactless digital voltmeter to measure tiny changes in the electric field down to milliVolts.

A feature of the sensors is that they are dry contact so that no gels or similar fluids are required to make contact.

The hand-held device, which the firm has called the imPulse, can record ECG signals without the need for conductive gel or skin preparation.

It detects an ECG signal when the user's two thumbs are placed on the two sensor pads which incorporate the EPIC devices.  

It measures the left and right signals and transmits the data via a Bluetooth link to a smartphone where custom software can then display the ECG trace and perform some simple analysis of heart rate. 

Earlier this year Plessey created a reference design for a wrist-strap heart rate monitor

Similar in size to a wrist watch, the reference design has a sensor electrode on the rear in permanent contact with the wrist, and a second electrode on the front of the device that has to be touched to get a reading.

According to Plessey's programme director Dr Paul James: "The data gathered is accurate enough that it can provide detailed ECG signals with the appropriate signal processing, including pulse rate and pulse rate variation. This opens up the possibility of estimating key aerobic performance parameters such as VO2max."