Alexander “Avi” Davidson lost his left hand and became paraplegic after falling 35 feet from a telephone pole, but this summer he did something he hadn't done in years: he held his wife's hand and actually felt it. The Tampa, Florida therapist is the first person to field-test, for an extended period, a bionic hand connected directly to his nervous system, taking the device home to use in daily life rather than only inside a research lab.
Davidson controls the prosthetic, known as the LUKE arm, with his thoughts, according to KSL, which first reported on his home trial. Surgeons attached tiny physical interfaces to nerves and some muscles in his left arm, and University of Utah researchers developed the computer-nerve interface that links the hardware to his body. The connection relies on the Utah Slanted Electrode Array, a 100-microelectrode grid invented by University of Utah professor emeritus Richard Normann that penetrates peripheral nerves to record motor signals and send sensory information back, according to University of Utah Biomedical Engineering.
Davidson began the home trial at the beginning of July after returning to Utah in April to practice using the new hand, per KSL's reporting. He was referred to the Utah NeuroRobotics Lab research project in 2025 by Stephen Saddow, and he consulted a rabbi about using the hand during the Sabbath, receiving approval to use it for truly necessary functions. He will keep the arm at home for a year, though according to lab director Jacob George, he may need to return it once the trial ends.
A Feedback Loop George Calls Embodiment
George, who heads the Utah NeuroRobotics Lab, described the system as a feedback loop that produces a sense of embodiment, the station's report notes. The lab is a joint venture between the University of Utah's College of Engineering and College of Medicine, and university engineers helped develop the LUKE hardware itself. Davidson said he now has a sense that the LUKE hand is genuinely his hand, and he described feeling joy from being able to feel his wife's hand in his own again.
The sensory feedback is not uniform across his fingers. Davidson described his thumb feedback as spot on, while his middle-finger feedback feels zappy and like pins and needles, per the same account. He said he can normally identify which finger his wife touches, and he has grown precise enough to pick out individual Mike and Ike candies for her by feel.
Getting there took work behind the scenes. Marshall Trout, a postdoctoral fellow at the Utah NeuroRobotics Lab, connected Davidson to a computer after his surgery so AI software could learn how his brain communicated with his hands. Davidson also receives weekly occupational therapy Zoom calls from Leanne Seckinger and says his dexterity has improved throughout the home trial, even as he acknowledged that his prior myoelectric hand had real limitations in lifting and control — one reason, he said, he still prefers an old-fashioned prosthetic hook for its simplicity in some situations.
Why So Few Patients Get This Chance
Davidson's opportunity is rare by design. According to George, eight other amputees will not have the chance to participate in this particular trial. The scale of unmet need is far larger than that: more than 540,000 people in the United States live with upper-limb loss, including roughly 41,000 with major amputations above the wrist, according to research published in PubMed Central.
That gap matters because so many existing prosthetics end up unused. Clinical literature reviews found that between 23% and 44% of upper-limb amputees eventually abandon their myoelectric or body-powered devices, largely due to a lack of sensory feedback, heavy weight, and discomfort — the exact problems the LUKE arm's nerve interface is designed to solve. The device traces its origins to DARPA's Revolutionizing Prosthetics initiative, launched in 2006 to help military veterans with limb loss, according to the Defense Visual Information Distribution Service, and DARPA invested more than $100 million in the technology before the FDA granted it marketing clearance in 2014.
Funding Uncertainty Clouds the Trial's Future
Even as Davidson's results generate optimism, the trial faces funding-related uncertainty tied to Trump administration cuts to National Institutes of Health funding. That uncertainty comes despite a record year for the university's research enterprise: University of Utah Health drew $531 million in research funding in fiscal year 2025, with $264.1 million of that coming from NIH grants, Hoodline previously reported. The lab has also leaned on private partnerships, including a $300,000 contract secured in December 2024 from commercial partner Biologic Input Output Systems to support ongoing clinical trials.
The Utah NeuroRobotics Lab is simultaneously working on ways to deliver similar sensory technology without surgery at all. That parallel research, led by George and Trout using AI neural networks and optical fingertip sensors, showed it could reduce mental fatigue and improve grip precision for amputees, according to a Nature Communications study Hoodline covered in detail. It is a lower-cost, lower-risk alternative to the invasive nerve surgery Davidson underwent, though it does not yet replicate the same depth of feeling he described.
Davidson's trial follows the LUKE arm's turn in the national spotlight, when the project was featured during a Super Bowl broadcast in February 2025 just before real-world, take-home trials began. LUKE stands for Life Under Kinetic Evolution, a name that now describes not just a piece of hardware but a year in which a paralyzed therapist from Florida learned, one candy and one handhold at a time, to trust a machine wired into his own nerves.
