Robotic arm for stroke patients

SINGAPORE - A new robotic arm can help stroke patients do these things: Lift their elbows and wrists up and down, and turn their forearms - movements necessary to pick up a cup, use a fork or spoon, or comb their hair.

Singapore Polytechnic's (SP) third-year engineering students, who came up with the arm, said this is the difference between their invention and those in the market.

"There are medical devices in the market that target the wrist or the elbow, but there are few devices that can do all three - extension and flexion of the wrist and elbow, and supination and pronation of the arm," mechanical engineering student Joern Yeoh, 21, told The New Paper.

The final-year project is a collaboration involving six electrical and electronic engineering students and five of their mechanical engineering colleagues.

The idea to develop a better robotic brace came from one of the team members whose relative had suffered a stroke eight years ago.

Student Ho Qian Ci, 20, said: "When my aunt's husband got a stroke, she was forced to take three cleaning jobs to support my three cousins. The family was stressed financially and mentally," he said.

Such a device would help a stroke patient recover faster, student Chia Wen Feng, 19, said.

"It's 2kg, made from carbon fibre - light enough to be carried home or from ward to ward," he said.

The students spent about nine months from March to December last year developing the prototype, working with three therapists from St Andrew's Community Hospital (SAHC), where they observed the movements of stroke patients and took measurements of their arms.

One of the challenges was to come up with a prototype that was ergonomic and modelled after the human arm.

SAHC's inpatient therapy services manager, Ms Anna Lee, said the therapists highlighted to the students the potential problems patients may have when using the brace and how they could finetune its movement, and any safety issues that needed to be considered.

Between April and October last year, the students made six prototype changes before settling on their final product.

Their efforts seem to have paid off.

Said SAHC's Ms Lee: "This lightweight arm brace definitely can help to restore a weakened arm due to stroke injury.

Its ability to provide passive range can facilitate a weakened arm to experience normal if not a functional range of movement."

The next stage is to apply for grants, refine the design, embark on clinical trials and approach companies to produce the brace, said Dr Lee Kim Kheng, senior lecturer of SP's School of Mechanical and Aeronautical Engineering.

He said: "We hope it will be used in community hospitals with the option for patients to rent the device."

The students estimate that the robotic arm can be sold for less than $2,000 and that some patients might want to buy it for home use.

Mr Gibson Chan, senior rehabilitation manager of St Luke's Hospital, said the invention would be an "extra help" and cut down the time taken for such devices to become available in Singapore.

He said: "Some products have been on the market for 10 years, but only arrived here two or three years ago. They are usually available in the US first, then Europe, and then, after some time, in China and Asia.

"This has usually to do with intellectual property rights. The students' invention can help bridge this gap, and more people can benefit from using the device."

Mr Ken Koh, 28, the managing director of Talentpreneur Hub, an entrepreneurship consultancy, said that SP could link up with existing players in the market.

"There are established distribution channels in place, competitors with vested interest," he said.

"The students should leverage on this, work with them, find out what else influences purchasing decisions by clinics or hospitals, instead of going against company A or B, because what (the students) have done is to have improved on an existing device."

The robotic arm brace is one of the 87 engineering projects on display at SP's Engineering Show. The show, which ends next Tuesday, is open to the public on Saturday.

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