World's Tiniest Pacemaker the Size of Rice Grain Could Be the Total Game-Changer For Heart Surgery

An international team of researchers has revealed a game-changing, self-sustaining, and biodegradable pacemaker, the size of a grain of rice, that may transform post-surgical cardiac care, especially in children.

The device is designed to replace hazardous complications associated with conventional pacemakers and could soon provide a safer, wireless option for pacing the heart after surgery.

The Problem With Traditional Temporary Pacemakers

World's Tiniest Pacemaker the Size of Rice Grain Could Be

After major heart surgeries that involve stopping the heart, patients usually receive a temporary pacemaker to stabilize heartbeats. According to Chemistry World, these conventional devices rely on thin, wired leads attached to an external power source. However, complications can arise when scar tissue forms around the leads.

Removing them risks damaging healthy cardiac tissue and causing potentially fatal internal bleeding, a complication tragically linked to astronaut Neil Armstrong's death.

How the Self-Powered Pacemaker Works

In contrast to traditional systems, this pacemaker is bioresorbable and employs electrodes of differing electronegativities directly implanted within cardiac tissue. It harnesses body fluids as a natural electrolyte to provide power. A phototransistor bridges the electrodes, keeping the circuit closed unless triggered by light.

This is where the innovation comes into play: a rechargeable lithium-polymer battery on the skin continuously tracks electrocardiograms. When it senses an abnormal heartbeat, it opens a pulsed LED light that passes through the skin to complete the pacemaker's circuit. This causes the device to provide accurately timed electrical impulses to the heart, restoring rhythm without invasive wires.

Small, Smart, and Safe for the Human Body

The whole device is implantable via a 3mm needle. It's biocompatible, non-toxic, and resorbs within the body between 1 and 3 years, depending on the materials employed. The remainder of the pieces are biocompatible and won't affect MRI scans.

Miniaturization of the device also enables multi-region heart synchronization, a challenging activity for existing temporary pacemakers, via varied wavelengths of light.

More importantly, its small size and wireless nature make it well-suited for pediatric patients, who frequently need pacemakers following cardiac surgery.

Toward Human Trials and Commercial Use

Although the device is currently in the preclinical stage, it has already been tested on animal models and explanted human hearts. Approval for medical devices usually takes 5 to 7 years, but the project team is hopeful. They are now set to apply for approval for clinical trials on living humans.

Alex Abramson of the Georgia Institute of Technology called the study "fantastic research," particularly praising the coordinated pacing through light. He also pointed out some drawbacks: the limited 40mm depth of light penetration and possibly shorter battery life if pacing is needed often.