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AI-powered bionic hand promises lifelike dexterity

BrainRobotics is trying out its prosthetics as it awaits FDA approval

Army Capt. Carey Duval tests the device. (BrainRobotics)
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Engineers at BrainRobotics have created a next-generation prosthetic that’s meant to be more mobile and affordable than other robotic limbs used today. It’s a hand powered by artificial intelligence that gives amputees precise control over each finger, enabling them to perform numerous gestures and grips.

The hand is undergoing FDA testing, and this month the company is testing the technology with the people it is intended to help.

In today’s world of brain-powered bionic limbs, highly functioning prosthetics are too expensive to reach many people who could benefit from them, researchers in the field say. The BrainRobotics device seeks to be the answer to that, with prices expected to start 30 percent lower than what’s on the market right now.

What primarily sets BrainRobotics’ prosthetic apart from those on the market is its algorithm, which detects minute muscle signals, converts them into hand movements and learns over time.

Harvard-backed BrainCo developed the robotic hand for people like Army Capt. Carey Duval. (Video: BrainRobotics/Biodesigns)

“The innovation is in the algorithm. It’s in the software,” said Max Newlon, president of BrainCo. “The innovation that gives our users this really precise, lifelike control is what sets us apart.”

The company was born out of Harvard’s Innovation Lab. Initially, it sought to control artificial limbs via brain signals but later found that measuring muscle signals was far more reliable, Newlon said.

Researchers developed the device for people like Carey Duval, an Army captain who lost his right hand in Afghanistan. He began testing the prosthetic in early December, spending a few weeks training to use the device proficiently. The robotic hand enabled him to complete activities such as playing Jenga and opening a water bottle with relative ease.

Other prosthetics without the BrainRobotics algorithm or as many grips made those tasks difficult to achieve, he said.

“I could flex inside the prosthetic, and it would change from a finger point to a two-finger pinch, and then from a pinch to a fist,” Duval said. “I could control a computer mouse and work a keyboard for the first time in a long time. I haven’t played a computer game in six years.”

Roughly 2 million Americans live with the loss of a limb, half a million of which are without upper limbs. Those seeking artificial hands have faced a landscape of static options offering limited functionality for years. Meanwhile, many of the robotic limbs that have cropped up either have physical buttons or require shaking to activate. They provide a limited number of finger motions, allowing wearers to switch between predetermined gestures.

The BrainRobotics hand prosthesis connects to a smartphone app via Bluetooth, maintains a charge throughout the day and can be programmed within a few minutes, the company says.

The hand is made using aviation-level aluminum and plastic. To set it up, amputees are instructed to “think” about moving individual fingers and making hand gestures while the prosthetic is attached. Meanwhile, the device measures and remembers what each signal looks like. It’s ready to operate within 15 minutes, the company says. After training, the robotic hand will respond to each of the muscle triggers it picked up during the exercise. So in practice, it can intuitively perform the users’ intended motions and gestures and become more lifelike over time.

BrainRobotics developed two versions of the hand: A two-channel prosthetic with two sensors attached to the wearer’s limb and a higher-functioning eight-channel prosthetic with eight sensors.

The company’s two-channel device enables up to 24 hand movements and is undergoing FDA testing, which it expects will be completed within the first quarter of 2021. Its eight-channel device with unlimited combinations of hand movements is next in the pipeline.

Prices are expected to start at about $14,000, or at least 30 percent lower than what’s currently on the market. Comparable prosthetics can cost $20,000 to $40,0000 per unit. Other bionic limbs that function similarly but look more like a human hand can cost up to $100,000.

The company works with prosthetic centers to get their technology to people like Carey, who is medically retiring from the Army.