While there are already pacemakers on the market that are so small that they fit inside the heart thus eliminating the need for electrode leads, these devices still depend on a battery that has a limited lifetime. Such implants require explantation and replacement eventually, procedures that can be difficult on patients, create additional cost, and pose challenge of choosing whether to have them implanted in the first place.
At the ongoing this week IEEE International Microwave Symposium (IMS) in Honolulu, Hawaii, researchers from Rice University and Texas Heart Institute are presenting a prototype pacemaker that uses a capacitor instead of a battery that can be recharged using a wireless transmitter. The microwave transmitter can stay outside the body, containing the actual battery that is the source of the system’s power. Because the capacitor is substantially large, it can also be used as a defibrillator, providing additional support to people at risk of dangerous arrhythmias.
The device, which doesn’t quite look like a final product yet, contains a CMOS chip with a built-in antenna and the electronics to convert the electrical signals and generate pacing signals. The pacing signals are controlled by increasing and decreasing the power output of the transmitter.
A pig served as the first subject on which the new pacemaker was tried on, the heart rate of which was successfully controlled between 100 and 172 bpms.
The researchers believe that because of the small size of the pacemarker, the lack of leads, and the ability to power it wirelessly may make it practical to pace both ventricles, since these days only the right ventricle is typically paced due to a number of factors.