New robotic device may improve stroke survivors' mobility

Researchers have developed a new robotic tool that may in combination with standard rehabilitation programme improve the mobility of patients surviving a stroke.

Stroke, known as a leading cause of long-term disability, is a sudden loss of brain function, caused by the interruption of blood flow to the brain or the rupture of a blood vessels in the brain and an estimated 150,000 people die from it each year. 

As a consequence of stroke, the survivors are often left with muscle overactivity, including spasticity, characterised by tight or stiff muscles and an inability to control those muscles. 

The study showed that the new robotic tool may help in assessing muscle overactivity and movement dysfunction in survivors of stroke.

The rehabilitation robotic system was found to quantitatively measure the three degree-of-freedom (DOF) impedance of human forearm and wrist in minutes.

Using their impedance estimation device, entitled the distal internal model based impedance control (dIMBIC)-based method, the team was able to accurately characterize the 3 DOF forearm and wrist impedance, including inertia, damping, and stiffness, for the first time.

"The dIMBIC-based method can be used to assist in the quantitative and objective evaluation of neurological disorders, like stroke," said lead author Sang Hoon Kang, Professor at Ulsan National Institute of Science and Technology (UNIST).

The results were published in the journal IEEE Transactions on Neural Systems and Rehabilitation Engineering.

"The findings will open a new chapter in robot-assisted rehabilitation in the workplace accident rehabilitation hospitals, as well as in nursing homes and assisted living facilities," Kang said.