Feature Article

The fingers are actuated by flexing the wrist. They feature moulded-in fingernails for picking up small objects.

When Matthew Mikosz, President of Partial Hand Solutions, saw the number of soldiers returning to the United States with hand and finger injuries, he decided to develop prosthetic fingers that would feel and operate as naturally as possible for the recipient. He built the prototype for the M-Fingers device with material development assistance from custom compounder RTP Co.

"While there were a number of prosthetic hand designs on the market, no functional mechanical fingers had yet been developed," explains Mikosz. "With M-Fingers, I saw an opportunity to give back to veterans who had lost something."

The M-Finger design uses an RTP 2300 Series glass-filled rigid thermoplastic polyurethane for the inner structure of the fingers and multi-position thumb. These are then overmoulded with an RTP 1200 Series thermoplastic polyurethane elastomer. The elastomer provides each finger with dexterity to independently and gently conform to whatever it grasps, while the rigid polyurethane material provides the product with strength and dimensional stability.

The mechanical fingers are actuated by wrist flexions and include moulded-in fingernails for picking up small objects such as coins. "With so many M-Fingers being used by soldiers in rehabilitation, it was important that RTP Company's materials provide both structural stability and, at the same time, the ability to move and operate the prosthesis smoothly," says Chris Budnick, General Manager of Vanguard Plastics, who was also involved in the development of the prosthetic hand. 

M-Fingers are distributed by Liberating Technologies of Holliston, MA, USA. Moulding of components was performed by Vanguard Plastics Corp. of Southington, CT, USA.