Oct. 12, 2023 — What if a pair of sticker-like sensors could turn your earbuds into a robust health monitor that would detect brain or mood disorders and treat them in real time with sound or electrical pulses?
Engineers on the University of California, San Diego are developing flexible sensors sufficiently small to slot in earbuds that may record brain electrical activity and lactate levels in sweat. One day, the sensors could monitor and treat conditions within the here and now by playing sounds or using electrical stimulation to influence brain activity, a latest type of therapy called “ Electroceuticals.
“We can hijack the acoustic signal to manipulate brain states toward more desirable outcomes,” said Gert Cauwenberghs, PhD, a senior engineer involved in the development of the sensors and a professor of bioengineering at the UCSD Jacobs School of Engineering. “These things are possible now that we can close the loop between producing sound and measuring brain activity.”
In a study published in NatureBiomedical engineeringThe sensors proved to be as effective as traditional monitoring methods such as electroencephalogram (EEG) headsets for brain activity and blood samples for lactate levels. However, unlike these methods, the sensors could be worn constantly outside the clinic while patients go about their lives.
The sensors are “spring-loaded” to maintain close contact with the ear and covered with a hydrogel film to absorb sweat. You can send data to the earbuds, which then transmit it to a smartphone or laptop via Bluetooth.
The use of in-ear devices for health monitoring is not new. But this is the first time brain and body sensors have been combined, opening the door for all kinds of research and clinical advances.
What could this technology do?
The researchers say this technology could be used to diagnose and treat a long list of conditions, from brain disorders such as Parkinson's, Alzheimer's and epilepsy, to mood disorders such as post-traumatic stress disorder, anxiety and depression. It could also detect and treat strokes, tinnitus, sleep apnea and traumatic brain injuries.
Much research has examined wearables for remote patient monitoring, but in-ear wearables could be particularly useful for conditions that impact the brain. Patients being tested for epilepsy, for example, could be monitored remotely and even wear the sensors at night to detect potentially undetected seizures, said Erik Viirre, MD, PhD, a professor of neuroscience at UCSD who is not involved in the research was.
In conjunction with the EEG measurements, changes in lactate could provide more clues for a diagnosis. For example, lactate tends to increase after an attack. Higher lactate levels can also indicate diabetes or heart disease. And monitoring lactate levels can prove useful in athletic performance.
Perhaps the most exciting potential application, however, is a “closed-circuit system” that can monitor and treat disease automatically and without human intervention. For patients with tinnitus, a ringing in the ears due to abnormal brain activity, the device could monitor the condition and test different sounds and play those that reduce tinnitus markers, Viirre said.
The technology could treat sleep disorders, cognitive degeneration, panic attacks or chronic pain in a similar way – by delivering music, breathing instructions, positive mantras or electrical stimulation and adjusting therapies based on real-time responses.
When can you get this technology?
It will likely take years before the device is tested and approved for clinical use, Cauwenberghs said.
But regular people could see in-ear wearables that track similar data sooner as more companies enter the market Growing market for “hearables” Earbuds that double as health trackers.
The ear is a first-class location, said Cauwenberghs. It's close enough to the brain to get a reading, and people already wear earbuds for extended periods of time. Therefore, the introduction of new technologies should not be a major obstacle.
The company NextSense works on an EEG measuring device, and STAT Health recently announced An in-ear device that can track blood flow to the head and predict fainting spells. Viirre envisions a world in which hearables can record even more biodata such as hormone levels, blood sugar and stress markers.
“Smartwatches can provide a lot of data, but in some ways they are very limited,” Cauwenberghs said. “Doctors don’t use it; it's more like a gadget.” Adding closed-loop technology could “make the difference between being able to see the weather forecast and being able to do something about the hurricane.”
“With this closed loop of biofeedback and neurofeedback, our vision goes far beyond monitoring,” he said.