FDA OKs Next-Generation Prosthetic Arm

The U.S. Food and Drug Administration (FDA) has approved the DEKA Arm System, the first prosthetic arm that can perform multiple, simultaneous powered movements controlled by electrical signals from electromyogram (EMG) electrodes.

EMG electrodes detect electrical activity caused by the contraction of muscles close to where the prosthesis is attached. The electrodes send the electrical signals to a computer processor in the prosthesis that translates them to a specific movement or movements. The prosthetic does not, however, return any sensation to the wearer, an attribute that recent research on other prosthetics has shown may be possible

The arm system is manufactured by DEKA Integrated Solutions in Manchester, N.H. The company was founded by Dean Kamen, the inventor of the Segway and other devices.

The EMG electrodes in the DEKA Arm System convert electrical signals into up to 10 powered movements, and it is the same shape and weight as an adult arm.In addition to the EMG electrodes, the DEKA Arm System contains a combination of mechanisms including switches, movement sensors, and force sensors that cause the prosthesis to move.

“This innovative prosthesis provides a new option for people with certain kinds of arm amputations,” said Christy Foreman, director of the Office of Device Evaluation at the FDA’s Center for Devices and Radiological Health. “The DEKA Arm System may allow some people to perform more complex tasks than they can with current prostheses in a way that more closely resembles the natural motion of the arm.”

The FDA reviewed clinical information relating to the device, including a four-site U.S. Department of Veterans Affairs study in which 36 DEKA Arm System study participants provided data on how the arm performed in common household and self-care tasks. The study found that approximately 90 percent of study participants were able to perform activities with the DEKA Arm System that they were not able to perform with their current prosthesis, such as using keys and locks, preparing food, feeding oneself, using zippers, and brushing and combing hair.

The DEKA Arm System can be configured for people with limb loss occurring at the shoulder joint, mid-upper arm, or mid-lower arm.It cannot be configured for limb loss at the elbow or wrist joint.

Data reviewed by the FDA also included testing of software and electrical and battery systems, mitigations to prevent or stop unintended movements of the arm and hand mechanisms, durability testing (such as ability to withstand exposure to common environmental factors such as dust and light rain), and impact testing.

The FDA reviewed the DEKA Arm System through its de novo classification process, a regulatory pathway for some novel low- to moderate-risk medical devices that are first-of-a-kind.

The Pentagon’s Defense Advanced Research Projects Agency (DARPA) said it provided more than $40 million in funding to DEKA to develop the robotic arm as part of a $100 million project to improve prosthetics.

“It was designed to produce near-natural upper extremity control to injured people who have suffered amputations. This arm system has the same size, weight, shape and grip strength as an adult’s arm would be able to produce,” Justin Sanchez, a program manager in DARPA’s biological technologies office, told Reuters. “This prosthetic limb system can pick up objects as delicate as a grape, as well be able to handle very rugged tools like a hand drill,” Sanchez said.

Until now, the best technology available to troops and other who lost an arm was a metal hook, Sanchez said. “The metal hook was the most commonly used prosthetic device for the last hundred years.”

According to the DEKA website, the arm is dubbed “Luke” after Luke Skywalker from the “Star Wars” series of films.