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Surprising Science

Stanford Researchers Test World’s Smallest Pacemaker

The bulky pacemakers of the present could be replaced by tiny mechanisms as small as a grain of rice. The secret to shrinking the devices is in how to power them wirelessly.

What’s the Latest?

Imagine a grain of rice that could keep your heart’s rhythms in check. A team of researchers at Stanford (and their lab rabbit) don’t have to imagine. The team of engineers, led by Professor Ada Poon, have been working on the device for several years. The major highlight of the world’s smallest pacemaker is the skin-permeating wireless energy source that powers the small device.

Lecia Bushak of Newsweek profiled the pacemaker and described how Professor Poon’s team developed its revolutionary wireless power system:

Researchers needed two types of electromagnetic waves—far-field and near-field—to penetrate deep into the body. Radio towers emit far-field waves, which can travel over long distances, while near-field waves travel over shorter distances and are used in hearing aids. But neither one is completely safe or effective in biological tissue: Far-field waves are reflected off or absorbed by skin, while near-field waves can’t travel very far inside the body. Poon’s team found a “sweet spot” by combining the two wave types to produce “mid-field” waves. The technique uses just about the same power as a cellphone but at levels well below the dangerous exposure minimum for humans.

What’s the Big Idea?

A typical pacemaker weighs about an ounce and its installation comes with the risk of infection and other health complications. Simply put, having something the size of a kiwi fruit installed in your chest isn’t the most natural thing for your body to cope with. The future of pacemakers was always going to be in making them smaller.

The reason pacemakers are so big in the first place is because their batteries tend to be bulky. That’s why safe and dependable wireless power is so important to the advancement of smaller devices. Wireless power also negates the necessity of having to undergo further surgeries to replace depleted batteries. According to Bushak, human testing of the device should begin in the coming in the year, though the technology still has several more to go before being made more widely available.

Read the abstract on the new technology here.

Keep Reading at Newsweek

Photo credit: Fodor90 / Shutterstock


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