Smartphone tech could enable stroke rehab at home

New technology that could allow stroke patients to undertake rehabilitation exercises at home is being developed by researchers at NYU Tandon School of Engineering.

For stroke survivors, regaining fine motor skills like writing and using utensils is critical for recovering independence and quality of life. Despite this, gaining access to intensive, frequent rehabilitation therapy can be challenging and expensive.

In order to assist with this problem, researchers are developing a new technology that could allow stroke patients to undergo rehabilitation exercises at home by tracking their wrist movements. This is done via a smartphone strapped to the forearm and the use of a low-cost gaming controller called the Novint Falcon.

The Novint Falcon, a desktop robot typically used for video games, can guide users through specific arm motions and track the trajectory of its controller. But it cannot directly measure the angle of the user’s wrist, which is essential data for therapists providing remote rehabilitation.

In a paper presented at SPIE Smart Structures + Nondestructive Evaluation 2024, the researchers proposed using the Falcon in tandem with a smartphone’s built-in motion sensors to precisely monitor wrist angles during rehab exercises.

“Patients would strap their phone to their forearm and manipulate this robot,” said Maurizio Porfiri, NYU Tandon Institute Professor and director of its Center for Urban Science + Progress (CUSP), who is the paper’s senior author.

“Data from the phone’s inertial sensors can then be combined with the robot’s measurements through machine learning to infer the patient’s wrist angle.”

The researchers collected data from a healthy subject performing tasks with the Falcon while wearing motion sensors on the forearm and hand to capture the true wrist angle. They then trained an algorithm to predict the wrist angles based on the sensor data and Falcon controller movements.

The resulting algorithm could predict wrist angles with over 90% accuracy, a promising initial step towards enabling remote therapy with real-time feedback in the absence of an in-person therapist.

“This technology could allow patients to undergo rehabilitation exercises at home while providing detailed data to therapists remotely assessing their progress,” said Roni Barak Ventura, the paper’s lead author who was an NYU Tandon postdoctoral fellow at the time of the study.

“It’s a low-cost, user-friendly approach to increasing access to crucial post-stroke care.”

The researchers plan to further refine the algorithm using data from more subjects. Ultimately, they hope the system could help stroke survivors stick to intensive rehab regimens from the comfort of their homes.

“The ability to do rehabilitation exercises at home with automatic tracking could dramatically improve quality of life for stroke patients,” Barak Ventura said.

“This portable, affordable technology has great potential for making a difficult recovery process much more accessible.”

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