Alex Smith, who lost his right arm in 2003 at the age of 11 after a drunk driver caused a boat collision on Lake Austin, has faced many challenges in finding effective prosthetic limbs. After the accident, Smith received a myoelectric prosthetic, which uses electrical signals from the remaining muscles in the limb to control the device.
However, Smith found this prosthetic difficult to use due to its slow response time and limited range of movement, which made it impractical for his daily life. Over the years, he experimented with various robotic arms, but none offered significant improvement in functionality.
Smith’s frustrations reflect broader challenges with current myoelectric prosthetics. These devices rely on surface electrodes that pick up electrical signals from muscle contractions, allowing the prosthetic to execute gestures.
However, these electrodes can move or slip, which affects the accuracy of the signals, making the prosthetics difficult to control in everyday situations. Additionally, most robotic arms have a limited range of gestures, and users must toggle between different functions, often making the prosthetic cumbersome to operate.
In contrast, a new technology being developed by the Austin-based startup Phantom Neuro promises a more natural and effective way for amputees to control prosthetic limbs. Phantom is working on a flexible muscle implant that would allow users to control their prosthetics by thinking about the gestures they want to perform.
Unlike traditional myoelectric devices, Phantom’s system aims to provide a wider range of movements and eliminate delays in response time, improving the overall user experience. The company has already tested a wearable version of its muscle sensor, which showed promising results in controlling a robotic arm with high accuracy.
In a recent study, Phantom tested its wearable sensor with 10 participants, including Smith, who used it to control a robotic arm. The results showed an impressive average accuracy of 93.8 percent across various hand and wrist gestures. While the wearable version showed promise, Phantom’s CEO, Connor Glass, acknowledges that the sensor is not ideal for daily use due to issues with slipping and recalibration.
Therefore, the company is focused on developing an implantable version that would provide more stability and reliability by directly picking up electrical activity from the muscle, bypassing the need for surface electrodes.
Phantom’s approach contrasts with existing prosthetics, which often require users to make unnatural movements to control the device. For example, to perform a simple pinching motion, a user might have to flex their wrist downward, which can be counterintuitive and cumbersome.
With Phantom’s implantable technology, the goal is to create a prosthetic that moves more fluidly and naturally, responding to the user’s intentions with minimal delay. Early studies have shown that the system can decode muscle signals with less than 200 milliseconds of latency, close to the natural speed of muscle movement.
Looking ahead, Phantom plans to conduct clinical trials for its implantable technology in 2025, aiming to recruit upper-limb amputees for the study. Smith, who participated in the wearable study, hopes to be involved in the clinical trial.
If successful, Phantom’s technology could revolutionize the way amputees use prosthetic limbs, allowing for more precise and efficient control that could dramatically improve their quality of life. Smith believes that this technology has the potential to be a “game changer” for amputees, enabling them to perform everyday tasks with greater ease and independence.
