Sensor measures speech patterns in stroke patients
A new wearable sensor designed to be worn on the throat is seen as a major advancement in rehabilitating stroke patients.
The bandage-like sensor measures patients’ swallowing ability and patterns of speech, aiding in the diagnosis and treatment of aphasia, a communication disorder that results in the loss of ability to understand or express speech, which is most often caused by stroke.
Traditionally, speech-language pathologists monitor patients’ speech function with microphones. However, these instruments cannot distinguish between patients’ voices and ambient noise, according to John Rogers, an engineering professor at Northwestern University who developed the throat sensor.
“Our sensors solve that problem by measuring vibrations of the vocal cords,” says Rogers, who gave a technology presentation on Saturday at the American Association for the Advancement of Science annual meeting. “But they only work when worn directly on the throat, which is a very sensitive area of the skin. We developed novel materials for this sensor that bend and stretch with the body, minimizing discomfort to patients.”
Rogers developed the throat sensor in partnership with the Shirley Ryan AbilityLab, a research hospital in Chicago that uses it in tandem with wireless biosensors on the arms, chest and legs—also developed by Rogers—to monitor stroke patients’ rehabilitation progress.
“We mount several of those devices strategically on different places on the patient’s body, and the folks at AbilityLab have developed algorithms to allow them—from those measurements—to determine early stages of spasticity,” adds Rogers. “They can also track a patient’s condition and monitor them in a home setting to determine their compliance with rehabilitation exercises.”
In addition, he contends that by using the biosensors that adhere directly to the skin, rehab regiments can be tailored to individual patients through the leveraging of data streams that are transmitted wirelessly in real time to clinicians’ Bluetooth-enabled mobile devices, providing a dashboard of physical and physiological responses that sends alerts when patients are underperforming on certain metrics.
“One of the biggest problems we face with stroke patients is that their gains tend to drop off when they leave the hospital,” said Arun Jayaraman, research scientist at the Shirley Ryan AbilityLab and a wearable technology expert. “With the home monitoring enabled by these sensors, we can intervene at the right time, which could lead to better, faster recoveries for patients.”
From a technology standpoint, the novelty is being able to build these types of devices in “skin-compatible, soft elastic form” that is “mechanically imperceptible” to patients, according to Rogers. “People won’t wear them if they are uncomfortable,” he adds.
Rogers has also developed a separate device for stroke patients that sticks to the skin and collects minute amounts of sweat, tracking the rate of sweating and certain biomarkers.
“That provides another very novel indicator of a patient’s status and their progression as a result of the rehabilitation,” he concludes. “It’s a little bit exploratory, but it appears to be yielding data that’s very valuable.”