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1.    From a doctor to an inventor

Fifteen years ago, Professor Yasunobu Handa is a doctor in Japan who was a researcher and practitioner of electrical stimulation to paralyzed patients in Tohoku University. He was a man who deeply cared for the recovery of his patients and often experimented with his own ideas to improve rehabilitation methods. His first idea was to combine both electric stimulation and a pedal wheelchair, using the current to spark the patient’s legs to pedal. The electric wiring was complicated and had difficulty in supplying enough stable power to keep the pedaling going.


One of his patients decided to try pedaling without electrical stimulation, and found that it worked! Professor Handa realized that using rehabilitation as a transportation device would allow the patient to rehabilitate at the same time, and eventually allow this person to return to an independent and social life.



Professor Yasunobu Handa, M.D., Ph.D

2.    First prototype: "The Tank"

The problem: The first model was too heavy (70-80 kg, or 154-176 lbs), so much so it was called “The Tank”.

3.    From invention to entrepreunerial pursuit


Mr. Kenji Suzuki, a young medical-device manufacturer and entrepreneur, met Professor Handa at a business meeting and was moved by the doctor’s heart to innovately help his patients. He set out to ask every wheelchair and bike maker in Japan, facing rejection after rejection. After being refused by 50 companies, there was one company left that he had not yet contacted, in fear of the CEO’s reputation for being a hard and successful man.

Kenji Suzuki, Profhand CEO

Mr. Shigeyuki Ishii, OX Engineering CEO

4.    An Olympic design

This Wheelchair designer/manufacturer’s name is Mr. Shigeyuki Ishii of OX Engineering, a world-wide renown company known for its designs which have won several Paralympic awards. After Mr. Suzuki contacted him, Mr. Shigeyuki lightly rebuked him for not having contacted him sooner and a week later came up with blueprints for what you see now as the innovative pedal wheelchair.


Working with his specialized team of designers and engineers, and the experience of designing top-of-the-line wheelchairs for specialty uses, Mr. Ishii was able to bring the wheelchair down to 12 kg (26 lbs).

Paralympic Wheelchair,

product of OX Engineering

5.    A birth of a design, a death of the designer

There was one more challenge to the effectiveness of the design of the wheelchair. Although the wheelchair could rotate 360 degrees in one direction, rotating in the other direction required a lot more effort and radius due to the gears of the wheelchair. The challenge brought university professors and company owners together to incorporate a design feature present in automobiles called the differential gear, into the innovation of this wheelchair. 


One of the co-inventors of the differential gear was killed during the Japanese tsunami in 2011. He had died shortly after an email he wrote to his colleagues stating how excited he was to present this new feature of the wheelchair. 

Differential gear

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