Hear a heartbeat in space

A new electronic stethoscope designed for NASA could deliver accurate heart and body sounds to doctors assessing the health of astronauts in a noisy spacecraft.

Despite the silence of space itself, the average spacecraft is a myriad of whirring fans, humming computers and buzzing instruments.

“Imagine trying to get a clear stethoscope signal in an environment like that, where the ambient noise contaminates the faint heart signal. That is the problem we set out to solve,” said Elyse Edwards, an engineering student at John Hopkins University.

Edwards worked on the project with fellow students Noah Dennis and Shin Shin Cheng under the guidance of James West, Research Professor in Electrical and Computer Engineering and co-inventor of the electret microphone technology first developed for telephones and now used in almost 90 per cent of more than 2 billion microphones produced each year.

Together, the students developed a stethoscope that uses both electronic and mechanical strategies in order for the device’s internal microphone to pick up sounds that are discernible even in a noisy spacecraft and even when the device is not placed perfectly correctly on the body of an astronaut.

The stethoscope has frequency filters and noise-cancelling headphones, signal processing capability, and a rubber cover and suction cup for the chest piece to absorb muscular tremors and minimise the movement of the chest piece on the skin.

The prototype also features low power consumption, rechargeable batteries and mechanically excludes ambient noise.

“Considering that during long space missions, there is a pretty good chance an actual doctor won’t be on board, we thought it was important that the stethoscope did its job well, even when an amateur was using it,” said Dennis.

Though originally developed for outer space, the device could also be useful on Earth, for example in noisy combat situations or in developing countries.

Further testing of the device will take place this summer.