Utah's BIOS Controller bionic arm enters its first home trial

Alexander “Avi” Davidson, 33, became the first person to take home a University of Utah direct nerve interface prosthetic arm for a year-long, unsupervised trial. He is the ninth participant in the university’s neuroprosthetics program. The eight before him worked with the device under supervision on campus. The home trial is a study design change, not a participant upgrade.

What the technology is

The arm is built on the LUKE Arm, a commercially available robotic prosthesis made by DEKA. What the University of Utah adds is the BIOS Controller, a direct nerve interface that replaces the LUKE Arm’s standard control method with thought-initiated movement. Electrodes implanted into residual peripheral nerves read motor intent and carry sensory information back: Davidson controls the arm by intending to move it, and the arm returns tactile signals he experiences as touch originating from the missing hand.

The bidirectional signal path is the feature that separates this from most prosthetic arm research. Many systems read motor signals out. Fewer send meaningful sensory information in. Jacob A. George, PhD, director of the Utah NeuroRobotics Lab, has been developing this approach since 2015.

What changed to make home use possible

Earlier iterations of the technology required calibration and troubleshooting support that made supervised, in-clinic use the only realistic option. The current software and AI iteration improves sensation fidelity, dexterity, and control intuitiveness to the point where the research team judged unsupervised daily use feasible.

That is an engineering judgment, not a clinical finding. The home trial exists precisely to test whether it holds when the environment is a real household rather than a controlled space. Within days of taking the arm home, Davidson reports being able to write, play cards, make a sandwich, and hold his wife’s hand while registering the pressure of her grip.

“The ability to have a return of sensation to my previously dominant hand is a life-altering experience,” Davidson said. “The ability to recognize how much pressure I’m putting on my wife’s hand and to feel hers back in mine is a wild idea to internalize.”

Davidson was 16 when he fell 35 feet from a telephone pole, leaving him with paraplegia and a left transradial amputation. The arm he is now taking home replaces the hand he lost seventeen years ago.

What the trial is actually measuring

A home trial answers questions a laboratory cannot. The central question is whether the technology is useful and intuitive enough that someone would choose to keep using it across the full range of their actual daily life, not only the tasks a supervised session happens to include.

Leanne Seckinger, the occupational therapist working with Davidson on integrating the device into daily life, identified sensation as the variable that expands what is possible. “Because of the presence of sensation, it allows that access to do more things in a different context that wouldn’t be possible with other prosthetic devices,” she said.

The one-year timeline gives the study enough data to separate early enthusiasm from sustained use. Many powered prosthetic arms are abandoned within months, often because the learning curve never pays off in functional return. If Davidson is still using the device at twelve months, that is worth noting. If he is using it across a wider range of contexts than he started with, that tells the research team something more specific about what the sensation feedback is actually enabling.

Where the FDA pathway currently sits

BIOS (Biologic Input Output Systems), the spin-out commercializing the direct nerve interface, received a Breakthrough Devices Program designation from the FDA in 2024. The device is also enrolled in the FDA’s Total Product Lifecycle Advisory Program, which provides early guidance on the regulatory pathway for promising experimental devices.

Both designations mean the FDA is engaged early in the development process. Neither is approval.

Breakthrough Device status accelerates the FDA’s review process for a premarket approval application, when one is filed. It does not lower the evidentiary bar. An implanted direct nerve interface is a Class III device, which requires premarket approval: the FDA’s most rigorous pathway, based on reasonable assurance of safety and effectiveness for the intended use. Safety and usability data from feasibility studies like this one feed into that application. The full pathway runs from ongoing feasibility data through pivotal trial design, enrollment, trial completion, application, and agency review. BIOS has not publicly announced a timeline for any of those later steps.

Davidson has previously used other robotic prosthetics. He said none of them match the BIOS version on range of movement, fine control, sensory feedback, or ease of use. That comparison matters to the FDA pathway: the question of what “effectiveness” means for a bionic arm depends partly on what the realistic alternatives are.

What this doesn’t establish

One participant in a one-year feasibility trial establishes feasibility. It does not establish efficacy at scale.

The prior eight participants worked in supervised settings, and data from those sessions contributed to the software improvements that made home use possible for Davidson. His year will do the same for whatever comes next. That is how early feasibility studies are supposed to work.

Whether the surgical procedure and interface calibration required to achieve Davidson’s reported experience can be replicated reliably across a broader population of arm amputees, including people with different residual anatomy, longer time since amputation, or different amputation levels, is a question this study is not designed to answer. The current trial is single-site, small, and carefully selected. That is appropriate for this stage. It is not a limitation to paper over.

George’s stated goal is to make the technology available broadly. The home trial is one step in that sequence, not the last one.

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Amputee News does not provide individualized medical or device-selection advice. The BIOS direct nerve interface is an investigational device under an FDA Investigational Device Exemption and is not available outside of clinical trials. Contact the University of Utah NeuroRobotics Lab directly through their published contact information for current trial eligibility and enrollment status.