Gravity gives us the ability to walk the Earth, but it also makes our hearts pump harder to move blood up against its force. The hearts of astronauts in space don’t have to pump so hard and will often relax too much and lose their ability to pump blood at the highest levels. This requires astronauts to compensate by regularly exercising and checking their cardiac health to make sure they’re staying fit. To help with that, researchers at Stanford developed a new ballistocardiograph (BCG) to detect worsening heart health even in microgravity environments.
Ballistocardiographs work by detecting the bumps that heartbeats generate on our bodies. You can feel and hear them by lying with your ear on a pillow in a quiet room, but usually ballistocardiographs work like typical weight scales and detect the slight change in a person’s weight during each beat. The problem of using ballistocardiography in space is that there’s not much weight to change with each beat. The Stanford team took an off-the-shelf scale and souped it up with some additional electronics to be ultra-sensitive enough to work in microgravity. To test it out they attached the new scales to the floor of the vomit rocket, a plane that simulates zero gravity, and successfully tested its ability to do ballistocardiography on healthy volunteers.Here’s a video from one of the test flights: