Technology has long been helping elderly people who fall and can’t get up to call for help — there are alarm bracelets, emergency-button necklaces and wireless motion sensors, for a start.

Now a UK energy firm is working on a system that can passively detect when something is wrong — Grandma won’t even have to push a button.

It is based on electrocardiograms, the same technology used to monitor your heartbeat. An EKG uses a series of electrodes that record signals from the heart. PassivSystems, based in Newbury, England, is working on a sensor that uses ultra-sensitive electrodes to detect the body’s influence on the ambient electric fields in a room.

A disturbance in the fields signals movement, and with enough algorithms and calibrations, the system could tell if someone has fallen or had a heart attack.

The electricity sensor can be used to detect brain, nerve fiber and muscle signals, as well as tell people apart. It can pick up these signals from about one and a half feet away, and PassivSystems is trying to increase that range.

The system was designed by Helen Prance and colleagues at the University of Sussex, England, and PassivSystems won a technology grant to further develop the concept.

It would be an improvement over existing room monitors, which use infrared heat sensors to detect a person’s motion. They have a hard time distinguishing among different people and require movement to work — not helpful for an elderly person who suffers a heart attack while sitting in a chair.

Telecare systems like the electricity sensor could allow elderly people to live independently for longer, PassivSystems says. And it could give families peace of mind, because they won’t be worried about adorning their loved ones with emergency-alert jewelry that they may forget to wear.

The Economist