MANCHESTER, NH —The Food and Drug Administration (FDA) recently allowed marketing of the first prosthetic arm that can perform multiple, simultaneous powered movements controlled by electrical signals from electromyogram (EMG) electrodes.
In the DEKA Arm System, 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, which is the same shape and weight as an adult arm, which then translates them to a specific movement or movements.
The EMG electrodes convert electrical signals into as many as 10 powered movements, in the DEKA Arm System, which contains a combination of mechanisms including switches, movement sensors and force sensors that cause the prosthesis to move. The product is manufactured by DEKA Integrated Solutions in Manchester, NH.
“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.”
Clinical information reviewed by the FDA included a four-site VA 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% 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.1
The DEKA Arm System can be configured for people with limb loss occurring at the shoulder joint, mid-upper arm, or mid-lower arm but not at the elbow or wrist joint.
The FDA review was performed through the agency’s de novo classification process, a regulatory pathway for some novel low- to moderate-risk medical devices that are the first of their kind.
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.
1Resnik L, Klinger SL, Etter K. User and clinician perspectives on DEKA Arm: Results of VA study to optimize DEKA Arm. J Rehabil Res Dev. 2014;51(1):27-38. doi: 10.1682/JRRD.2013.03.0068. PubMed PMID: 24805891.