Robotic Rehabilitation Could Help Stroke Patients Recover

New tool assesses 3 degree-of-freedom impairment in minutes.

A recent study has introduced a new robotic tool for assessments of muscle overactivity and movement dysfunction in stroke survivors. Their robotic-assisted rehabilitation therapy, combined with standard rehabilitation, is expected to improve the mobility of patients surviving a stroke.

The research was led by Sang Hoon Kang, a professor of mechanical, aerospace and nuclear Engineering at Ulsan National Institute of Science and Technology (UNIST) in collaboration with professor Pyung-Hun Chang of Daegu Gyeonbuk Institute of Science and Technology (DGIST) and Kyungbin Park of Samsung Electronics Co. Ltd.

In their study, published in IEEE Transactions on Neural Systems and Rehabilitation Engineering, Professor Kang and his team developed a rehabilitation robotic system that quantitatively measures the 3 degree-of-freedom (DOF) impedance of human forearm and wrist in minutes.

The experimental setup for the estimation of the 3 DOF human forearm and wrist impedance. (Image courtesy of UNIST.)

The experimental setup for the estimation of the 3 DOF human forearm and wrist impedance. (Image courtesy of UNIST.)

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.

Strokes are a leading cause of long-term disability and stroke survivors are often left with muscle overactivity, including spasticity, a muscle control disorder that is characterized by tight or stiff muscles and an inability to control those muscles. It is often manifested by increased stretch reflex activity and mechanical joint resistance.

“The dIMBIC-based method can be used to assist in the quantitative and objective evaluation of neurological disorders, like stroke,” said Professor Kang. “Findings from this study 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.”

The research team expects that, in the long run, the proposed 3 DOF impedance estimation may promote wrist and forearm motor control studies and complement the diagnosis of the alteration in wrist and forearm resistance post-stroke by providing objective impedance values including cross-coupled terms.

For another example of how engineers are advancing medicine, check out this wireless pacemaker.

Source: Ulsan National Institute of Science and Technology (UNIST)