Groundbreaking Subcutaneous Implant Promises to Revolutionize Prosthetic Control for Amputees: PhantomNeuro's Neural Technology Innovation

Groundbreaking Subcutaneous Implant Promises to Revolutionize Prosthetic Control for Amputees: PhantomNeuro's Neural Technology InnovationPhantomNeuro, a neural technology startup, is developing a groundbreaking subcutaneous implant designed to provide amputees with a more precise and natural way to control prosthetic limbs. This innovative technology aims to address the limitations of current myoelectric prosthetic control systems, such as slow response times, limited range of motion, and inconvenient use, significantly improving the quality of life for amputees

Groundbreaking Subcutaneous Implant Promises to Revolutionize Prosthetic Control for Amputees: PhantomNeuro's Neural Technology Innovation

PhantomNeuro, a neural technology startup, is developing a groundbreaking subcutaneous implant designed to provide amputees with a more precise and natural way to control prosthetic limbs. This innovative technology aims to address the limitations of current myoelectric prosthetic control systems, such as slow response times, limited range of motion, and inconvenient use, significantly improving the quality of life for amputees.

Alex Smith, an amputee who lost his right arm in a boating accident at age 11 (a collision in 2003), experienced firsthand the limitations of traditional myoelectric prosthetics. He tried various myoelectric arms but found their slow response times and limited range of motion inadequate for everyday tasks. He confessed, "The functionality wasn't sufficient. There was a huge delay between wanting to perform a function and the prosthetic actually responding. In daily life, I found it faster to do things other ways." This common user experience is the core problem PhantomNeuro is tackling.

Currently, most myoelectric prosthetics rely on surface electrodes placed on the residual limb to read electrical impulses from muscles. These surface electrodes, typically with only two or a few recording channels, are prone to slippage and displacement, leading to unstable signals and reduced control precision. Furthermore, the range of motion offered by existing devices is extremely limited. Even when users can perform some basic gestures, they often require extra, unnatural movements. For example, a simple grasping action might necessitate deliberate wrist flexion. Alex Smith's current prosthetic can perform approximately 20 gestures, but he can only program four at a time, sequentially switching between themhe can't directly transition from one gesture to another.

This is not an isolated case. A 2020 survey of upper-limb amputees revealed that only 20.7% used myoelectric prosthetics, while 74.4% used body-powered prosthetics, requiring coordination between the residual limb and the intact arm. More concerningly, 44% of those who initially used myoelectric prosthetics ultimately abandoned them. These statistics strongly demonstrate the shortcomings of current myoelectric prosthetic technology and the urgent need for a more advanced and convenient control system.

PhantomNeuro's solution lies in its thin, flexible muscle implant. This implant directly interfaces with the muscle, capturing electrical activity at the muscle surface to more accurately interpret the user's intended movements, enabling a wider and more natural range of motion. Users simply think about the movement they want to make, and the prosthetic responds accordingly. Connor Glass, CEO and co-founder of PhantomNeuro, stated, "Very few people use robotic limbs, primarily because the control systems are so bad."

To validate its technology, PhantomNeuro conducted a study. Ten volunteers (including Alex Smith and nine able-bodied individuals) used PhantomNeuro's wearable sensor system to control commercially available robotic prosthetics. The results showed an average accuracy of 93.8% across eleven hand and wrist movements. This successful study paved the way for future testing of PhantomNeuro's implantable sensor.

While the wearable muscle sensors performed well in a laboratory setting, Connor Glass acknowledges that they are not ideal for everyday use due to slippage and the need for frequent recalibration. The implantable device, however, promises greater reliability and accuracy because it directly captures electrical activity from the muscle surface without the signal attenuation and interference introduced by the skin.

Connor Glass envisions the sensors being implanted subcutaneously through a small incision. "We get the electrical activity directly from the muscle surface," he explains. A wearer's intended movement originates in the brain, which sends electrical impulses through peripheral nerves to command muscle contraction. For amputees, these neural pathways remain intact. PhantomNeuro's implant leverages this mechanism.

In the wearable device study, volunteers received one hour of training and performed the experiment the following day. After a 10-minute algorithm calibration on the day of the experiment, volunteers repeatedly performed eleven gestures, including opening the hand, making a fist, pinching, extending the thumb, pointing with the index finger, index finger tapping, inward wrist rotation, and outward wrist rotation. PhantomNeuros software learned and decoded their muscle signals, translating them into actual movements. For able-bodied volunteers, this meant the robotic prosthesis mirrored their gestures; for Alex Smith, it meant the prosthesis flawlessly executed his intended actions. "It was the coolest experience," he enthused.

Each volunteer wore two very thin sensors, each with sixteen electrodes. Gesture decoding accuracy ranged from 84.8% to 98.4%, with a delay of less than 200 milliseconds between detecting the electrical signal and executing the gesture. Considering that the human delay between neural signal arrival at the muscle and actual movement is approximately 100 milliseconds, PhantomNeuro's delay is remarkably close to the body's natural neural response speed.

Paul Marasco, a neuroscientist at the Cleveland Clinic (not involved with PhantomNeuro), commented, "The speed at which they achieve this accuracy of gestures is remarkably fast. The faster you can do that, the better off you are, and the more seamless the whole system becomes."

Some companies are developing brain implants to allow paralyzed individuals to control prosthetics with their minds. While such brain-computer interfaces hold great promise, they also carry greater risks and require longer lifespans to avoid multiple brain surgeries. Geoffrey Ling, a PhantomNeuro advisor and founding director of the Defense Advanced Research Projects Agency's Biological Technologies Office, noted, "The peripheral nerve is a very attractive approach because it's minimally invasive." PhantomNeuro believes its implant can be inserted in an outpatient procedure and doesnt require a specialized surgeon.

PhantomNeuro plans to begin clinical trials of its implantable muscle sensor in 2025, recruiting upper-limb amputees. Alex Smith hopes to participate. If PhantomNeuro's technology reaches commercialization, he believes it will revolutionize the lives of amputees, enabling them to perform everyday tasks with greater ease. "I think this is going to be a game changer," he said. This technology is not only significant for amputees but also represents a breakthrough in neural technology, offering hope and potential benefits for many more individuals in need.