A research breakthrough has identified a way to charge tiny health-tracking devices that could be embedded in our brains, hearts or livers

A breakthrough in wireless technology could allow a new wave of health tracking tools that can be embedded inside our bodies – in our livers, hearts and even in our brains.



A new wireless charging technique known as “mid-field wireless transfer” can deliver power to tiny electronic devices such as sensors, pacemakers and nerve stimulators embedded deep within the body. They can be charged using a device the size of a credit card placed outside the body.

"With this method, we can safely transmit power to tiny implants in organs like the heart or brain, well beyond the range of current near-field systems,” said Dr John Ho, co-author of the study that appears in the Proceedings of the National Academy of Sciences.

‘Make these devices as small as possible’

Sensors can be embedded deeper into the right areas of the body, without needing to be close to the skin for current near-field wireless charging technologies like those that charge electric toothbrushes. The embedded devices will also no longer need large, bulky batteries, which means it is possible for them to fit into tighter, more sensitive spaces.

“We need to make these devices as small as possible to more easily implant them deep in the body and create new ways to treat illness and alleviate pain," explained Professor Ada Poon, lead researcher behind the new technique in a press release.

An example of a tiny wireless power module that could be implanted in the body.

Current implantable devices such as pacemakers use large, long-life batteries which often need replacing, requiring more surgery, while others use near-field wireless charging and therefore need to be placed close to the skin.

Poon’s team developed a new type of near-field wave that propagates through skin and body tissue, rather than be reflected like longer wavelengths or absorbed by like typical near-field chargers. The wireless charging emits waves at roughly the same power levels of a mobile phone, and is therefore deemed safe for use.

The researchers demonstrated the power delivery technology in a pig and a rabbit, which had a tiny pacemaker fitted solely powered by the wireless technique.

‘Paving the way for new innovation’

The discovery opens up greater possibilities for medical implants called “electroceutical" devices, which use electrical stimulation to treat illness or alleviate pain that would typically require longterm drug treatment. Diseases like Parkinson's are already treated with techniques like deep brain stimulation to control shaking symptoms.

Beyond medical devices, one of the largest stumbling blocks to embedding computing devices and sensors in the body has been supplying them with power. With the ability to power them the possibility of embedding fitness trackers, biosensors such as heart rate, blood glucose and hormone monitors, or any other small electronic devices within the body has been opened up.

“The Poon lab has solved a significant piece of the puzzle for safely powering implantable microdevices, paving the way for new innovation in this field,” said William Newsome, director of the Stanford Neurosciences Institute.

Having proved that the technique works in animals, Poon and her team are currently preparing for human testing, which will require approval from safety regulators and will take several years before the technology will be certified for use in medical devices and beyond.

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