Pacemakers have gotten so small that they can now reside inside the heart itself. This avoids reliance on electric leads that snake from the implant to the interior of the heart, which come with a number of potential problems. On the other hand, advanced multi-site sensing leads are able to provide considerably more nuanced monitoring of the heart than a pacemaker attached to one spot in the heart.
Students at Rice University are working on overcoming this limitation by developing a very different approach. They are working on tiny, grain of rice sized implants a number of which would be permanently adhered to the heart and that would both sense and help pace it. Their energy comes via wireless electromagnetic transmission from a larger device placed outside the heart, but in its vicinity.
Here’s a video from Rice University about the project: