Finally, we have this little device, created by Dr. Robert Jarvik—the man many credit with the invention and perfection of the artificial heart. And that’s exactly what that battery-sized device is: the world’s smallest artificial heart, for the world’s smallest artificial heart patient.

The 16-month-old baby had dilated cardiomyopathy, a degenerative condition of the heart wall, and was awaiting a transplant. But with no donor immediately forthcoming, doctors were forced to improvise. Jarvik’s device, an implantable pump weighing all of 11 grams (an adult artificial heart weighs 900 grams), had only been tested on animals. (It is connected to tubes that must run outside the body, thus escalating the risk of infection.) But in May 2012, with nothing to lose, the doctors proceeded to remove the infant’s heart and replace it with the device in the image above, where it remained for 13 days.

This was, of course, how long it took for a transplant donor to be found, and while the device would not have kept the patient alive indefinitely, the doctors who participated say that this could definitely be on the horizon. We find this to likely be an understatement. At the rate technology continues to shrink, we can see an easily removable, shot glass–sized RoboHeart with a 300-year warranty on the shelf before we’re old enough to need one.