Miniature health-trackers that could be implanted inside the brain to monitor various parameters or enable control of prosthetic devices are being developed by American researchers.
Described as deep-tissue ‘Fitbits’, the sensors are about the size of a grain of sand. They harness energy from ultrasonic waves using piezoelectric crystals. The electricity generated by the crystals powers minuscule transistors attached to nerve cells inside the body. The collected data is then sent wirelessly in real-time to an external device using the same ultrasound signal.
"You can almost think of it as sort of an internal, deep-tissue Fitbit, where you would be collecting a lot of data that today we think of as hard to access," said Michel Maharbiz, an associate professor of electrical engineering and computer science at the University of California, Berkeley, referring to the popular American wearable gadget.
The researchers have tested the sensors in rats. They managed to successfully monitor the animals’ peripheral nervous system.
The team says the technology could be used to monitor patients with epilepsy and other conditions or to enable amputees and quadriplegics to better control their prosthetics.
"It's a meaningful advancement in recording data from inside the body," Eric Leuthardt, a professor of neurosurgery at Washington University in St Louis, commented on the development. "Demonstrations of capability are one thing, but making something for clinical use, to be used as a medical device, is still going to have to be worked out."
The Berkeley team hopes to test the devices in human patients within two years. By then, the researchers would have to further decrease the size of the devices to approximately 50 microns.