Scientists develop cardiac pacemaker powered by heartbeat

A research team has developed an implantable medical device that can harvest energy from heartbeats rather than batteries, according to a recent report published in the journal Nature Communications.

The cardiac pacemaker was designed on the basis of an implantable triboelectric nanogenerator, which can achieve energy from heartbeats and convert the energy to electricity for powering pacing pulses.

According to the study, the device and the body form an interconnected symbiotic system. Both the energy source and stimulus target of the symbiotic device is the body.

Researchers from China and the United States tested the self-powered device in pigs and found that the energy harvested from each cardiac motion cycle is 0.495 microjoule, which is higher than the required pacing threshold energy of humans (0.377 microjoule).

“We conducted tests on pigs because pig hearts are about the same size as human hearts,” said Li Zhou, a researcher with the Beijing Institute of Nanoenergy and Nanosystems under the Chinese Academy of Sciences.

Current implantable medical devices are powered by batteries, which are bulky, rigid and have short lifespans owed to self-discharge, low energy density and inflexible packages.

In addition to high output performance, the results of the study show that the triboelectric nanogenerator has advantages of light weight, good flexibility and durability.

The cardiac pacemaker is used to maintain an adequate heart rate. The study has also proven the ability of the new pacemaker to correct sinus arrhythmia, an irregularity in the heart rhythm, and prevent deterioration to conditions that may lead to death.

Researchers believe the device will have a wide range of applications as it may act as a direct electrical stimulation source for tissue engineering, nerve regeneration and stem cell differentiation.

There are still challenges for the pacemaker to overcome to reach clinical applications, Li said. “We will improve the device by making it smaller and more efficient with longer-term biosafety in further studies.”