Fighting fit

A small Cambridge, UK electronics company is claiming a major coup after signing a deal to supply the US Army with miniature bio-sensor technology that monitors soldiers’ health in the battlefield.

The Equivital Life Monitor (ELM) is a chest-mounted system that uses an array of sensors to assess a soldier’s physiological status.

It was developed by electronics design specialist Hidalgo, which adapted its existing bio-monitoring technology to meet parameters set by the US military.

The company’s managing director Justin Pisani claimed the ELM is the first physiological monitoring system that is practical for use by soldiers in the field.

The credit card-sized unit monitors the wearer’s heart rate, skin temperature and a range of other health indicators. A motion sensor classifies the wearer’s rate of movement as stationary, low or high, while a body position sensor decides whether soldiers are upright, laying flat or hanging upside down.

According to Pisani, the challenge was miniaturising the electronics to make the system small and light enough for soldiers to wear. Previous adapted medical monitors have weighed as much as 5kg which proved impractical for battlefield use, he claimed. The ELM weighs 75g.

‘The difference between this and traditional monitoring is that usually a clinician looks at data and analyses it,’ said Pisani. ‘But because of the limits of battlefield communications we use integrated analysis electronics to simply send a signal back to say “I’m okay”.’

ELM uses custom-developed algorithms to process the data from the sensors to form a ‘Physiological Welfare Index.’ This data is transmitted to the control centre as one of three classifications from red, meaning the wearer is at high risk, through to green, which indicates their physiology is normal. Amber prompts medical staff at the control centre to call up the soldier’s parameters by requesting the unit operate in full-disclosure mode.

Pisani said: ‘Being able to dramatically cut the information sent back from a wearer to a simple indication of welfare makes it possible to monitor a number of people over a wide area.’

Hidalgo has also designed a version of ELM that communicates via the emergency services’ TETRA radio network, and an even smaller version called Equivital Light, which is designed for use by lone workers such as social workers and nurses.