Myoelectric Prosthesis Wins Freescale Design Challenge

A graduate student engineering team from Guadalajara, Mexico has won the $10,000 Freescale Semiconductor Black Widow Design Challenge by developing a myoelectric prosthetic hand that cost only $1,600 to build. The design could be significant because it lowers the cost of building such a hand by a factor of approximately 20 times.

The team from the Universidad Jesuita de Guadalajara, introduced during the keynote speech at this week’s Freescale Technology Forum, designed the hand using a $1.05 Freescale microcontroller as its primary control element.

“There are commercial prostheses that can do what this hand does,” said Gabriel Herrera Orozco, a team member and graduate student at the school, “but they usually cost about $40,000.”

The team of graduate students designed the prosthesis to benefit hand amputees living in world regions where more affordable health care products and services are needed. Throughout the design process, the team said it focused on minimizing system cost without compromising user comfort and product functionality.

A conventional myoelectric prosthesis works by receiving electrical signals produced by the contraction and relaxation of various muscle groups. The Guadalajara team used those electrical signals to facilitate opening and closing of the hand, as well as left and right wrist rotation.

The prosthesis, developed in about four months, uses conventional DC motors powered by a 12V battery and controlled by a Freescale eight-bit S08 microcontroller. One DC motor is responsible for opening and closing the hand; the other handles wrist rotation.

The team designed the hand to employ variable pressure. “Using this prosthesis, an amputee can grab a glass or plastic bottle without damaging it,” Orozco said.

Freescale also gave out second- and third-place awards in the Black Widow contest, which derived its name from the idea of the so-called “killer app.” Rakesh Reddy, an engineering student from Marquette University took second for the design of an Etch-A-Sketch prototype that enables sketches to be saved, retrived and recreated electronically on a tablet controlled by an S08 MCU. Also, a team from Archronix, a technology design firm, took third by developing an S08-based handheld medical device for doctors, chiropractors and massage therapists.

	A student team from Guadalajara won Freescale’s Black Widow Design Contest for its development of low-cost hand prosthesis.