World's smallest pacemaker, smaller than the size of a rice grain, is here: How it works

In a breakthrough development, scientists from Northwestern University, have unveiled the world's smallest pacemaker, tinier than one could ever imagine- even smaller than the size of a rice grain. The revolutionary device, in the early stages of development, offers a temporary solution for regulating heartbeats and could dramatically change the future of heart care. The findings have been detailed in a study published in Nature.

Powered by light and capable of dissolving into the body once no longer needed, this pacemaker marks a significant leap forward in medical technology.

While it would take years before it can be tested in humans, the wireless pacemaker is considered a "transformative breakthrough" which could also pave the way for other advancements in other areas of medicine.

“We have developed what is, to our knowledge, the world’s smallest pacemaker,” said Northwestern bioelectronics pioneer John A. Rogers, who led the device development. “There’s a crucial need for temporary pacemakers in the context of pediatric heart surgeries, and that’s a use case where size miniaturization is incredibly important. In terms of the device load on the body — the smaller, the better.”

“Our major motivation was children,” said Northwestern experimental cardiologist Igor Efimov, who co-led the study. “About 1% of children are born with congenital heart defects — regardless of whether they live in a low-resource or high-resource country. The good news is that these children only need temporary pacing after a surgery. In about seven days or so, most patients’ hearts will self-repair. But those seven days are absolutely critical. Now, we can place this tiny pacemaker on a child’s heart and stimulate it with a soft, gentle, wearable device. And no additional surgery is necessary to remove it.”

A permanent or classic pacemaker is a device that can be placed in your body, usually by surgery, to support the electrical system in your heart. This helps in stabilizing abnormal heart rhythms and preventing problems that can disrupt or endanger your life.

What is the difference between a permanent pacemaker and a temporary pacemaker?
In some cases, a pacemaker is needed for a short time to assist heart function. This is especially done when heart rate changes owing to open-heart surgery, heart attack, infection, medication or other issues. This kind of pacemaker stays in place until your heart rate is stabilized, typically for just a few days. Permanent pacemaker is implanted only when things don't improve on their own.

Another distinctive trait that sets the new pacemaker apart is its ability of being wireless. It's just one millimeter thick and 3.5 millimeters long, and can fit into the tip of a syringe. Besides it doesn't have to be taken out from the body as it is designed to dissolve into the body when no longer needed.

Temporary pacemakers currently need surgical procedure to sew electrodes onto heart muscles, with wires connecting to a powered device on the patient's chest. When the pacemaker serves its purpose, doctors or nurses pull out the wires, which can at times cause damage.

How the tiny pacemaker works

The pacemaker is connected to a soft patch worn on the patient's chest, as described in a study published in the journal Nature.

When the patch detects irregular heartbeats, it emits a light signal that instructs the pacemaker on the appropriate heartbeat to stimulate.

The pacemaker is powered by a galvanic cell, which harnesses the body’s fluids to convert chemical energy into electrical pulses that regulate the heart.

According to the study, the pacemaker has shown effective results in tests on mice, rats, pigs, dogs, and human heart tissue in the lab.

When are human trials expected to be launched?

Senior study author John Rogers of Northwestern University in the United States told AFP that the pacemaker could be tested in humans in approx. two to three years and his lab has launched a start-up for the same.
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