In prosthetics, our ultimate goal should transcend the physical act of mere device delivery and extend into the realm of total device embodiment. This research is very interesting as it highlights the brain’s ability to adapt and change in significant ways. Prosthesis acceptance is a problem many struggle with and it is evident from the feedback we receive from amputees and others. Many prosthesis wearers come to us specifically because they are seeking a better connection to their prosthesis. They report that they feel very disconnected from their px, often stating it feels heavy, uncomfortable, inefficient, and unstable, resulting in a high risk and fear of falls. On the contrary, in our clinic and with our HiFi Licensees, we continue to document that most of our HiFi Prosthetic Interface wearers state their prosthesis feels like a part of them, feels significantly lighter, moves with them, and many report phantom sensations lost long ago now returning, allowing them to feel the ground, make quick adjustments and prevent falls. Some even forget they are wearing their prosthesis, the ultimate indication of device embodiment. I believe this to be the result of our High-Fidelity Interface’s emphasis on proper biomechanics, a term too often tossed around casually when referring to standard of care sockets with near total disregard for uncontrolled bone motion. Proper biomechanics is impossible if the primary mover is flailing about within the socket. With our patented and patents-pending osseostabilizing technology that was designed from its inception to control unwanted translation of the underlying bone shaft, we achieve a syncing of the prosthesis with skeletal motion. This synchronization in concert with a strongly activated fascial sensor network from targeted compression is a better match to the condition experienced prior to limb loss, allowing natural stimulation of the brain that is more representative of a sound limb. With skeletal control, the wearer can distance themselves from the artificiality of poorly connected prosthetic devices, allowing their brain to better “accept” this new condition and more fully incorporate it into the sense of self. In other words, get on with the business of living. While this is a great breakthrough in prosthetic technology, the limiting factor here is not our brain, as noted above, it instead is our industry’s reluctance to change, inability to break long established fitting habits (that yield subpar results), and refusal to acknowledge that perhaps the way we did things in the past was detrimental to our patients. My hope is to continue to work with those individuals, researchers, allied health professionals, etc., that continue to look forward – not backwards.
In the March 2021 issue of the O&P Edge, Randall Alley, CEO and Head of User-Interface Technology, notes the issues with existing prosthetic socket designs and introduces a new model to consider for attachment, the Biotensegrity Bridge™, and describes how the patented and patents-pending HiFi Interface™ System creates a stable and functional “bridge” for attaching prosthetic devices.
“Since soft tissue (fascia) has a nonlinear stress/strain arrangement, traditionalists have incorrectly applied linear laws using levers and pulleys (mechanical physics) to explain the effects that the forces of gravity and tension elicit on our bodies. Biotensegrity has emerged as a new model of structural biology that is in diametric opposition to the Newtonian model of linear mechanical forces we all learned in school. Understanding the dynamic and continuous relationships between the soft tissue (fascia) and fluids within the body opens up new and exciting opportunities for better understanding the nature and role of the human-device interface,” stated Alley. “I give you what I am terming the Biotensegrity Bridge™ as a better way to approach interface integration.”
biodesigns, in California, best known for their prosthetic interface/socket technology, recently delivered an advanced arm system during this unusual time as a result of the Corona Virus. “We consider our business vital to our patients and want them to know we are here for them,” stated Randall Alley, CEO, Chief Prosthetist for biodesigns. The system delivered included advanced technology including Alley’s patented and patents-pending HiFi interface design, Coapt Engineering’s Gen2 Pattern Recognition, College Park’s Espire Powered Elbow, and Motion Control’s Wrist Rotator and External Terminal Device (ETD2). The system will also be used with the user’s existing ilimb Quantum hand. biodesigns takes great pride in designing prosthetic systems that are appropriate for their users. “This user is long time wearer that has proven time and time again the many functional benefits he receives from his prostheses,” stated Alley.
“There is definitely a preconceived notion that a body-powered system is lighter, but with this HiFi socket it makes the arm feel just as light as body-powered. There is more stability across the entire length of the arm. There are no pinch points, way more degrees of freedom, more responsive, better connection to all the sensors.”
Arlene, a below-knee amputee for almost 20 years, couldn’t believe the difference between her traditional socket and her new HiFi. With the HiFi, “it feels so much more natural. I don’t have to think about walking. That’s Amazing!” In my old socket, it “feels like I’m going to go down. The knee is going to buckle. It’s a little scary.” Arlene shows the HiFi can help users of all ages. Everyone can benefit from HiFi’s ability to provide added stability and control.
“I would never go back to my old socket system. This combination with the Triton foot, Genium knee and HiFi Socket is everything to me and everything I have been waiting for. I can’t see my life without it.” – Ali
ABSTRACT. Traditional function and comfort assessment of transradial prostheses pay scant attention to prosthetic interface. With better understanding of the biomechanics of prosthetic interface comes better efficiency and safety for interface design; in this way, amputees are more likely to accept prosthetic usage. This review attempts to provide design and selection criteria of transradial interface for prosthetists and clinicians. Various transradial socket types in the literature were chronologically reviewed. Biomechanical discussion of transradial prosthetic interface design from an engineering point of view was also done. Suspension control, range of motion, stability, as well as comfort and safety of socket designs have been considered in varying degrees in the literature. The human–machine interface design should change from traditional “socket design” to new “interface design.” From anatomy and physiology to biomechanics of the transradial residual limb, the force and motion transfer, together with comfort and safety, are the two main aspects in prosthetic interface design. Load distribution and transmission should mainly rely on achieving additional skeletal control through targeted soft tissue relief. Biomechanics of the residual limb soft tissues should be studied to find the relationship between mechanical properties and the comfort and safety of soft tissues.
Jessica, an above knee amputee, struggled with finding a socket – until she found the HiFi. “The HiFi is amazing.” “Get out of my way when I’m on this socket.” “This is what you need.”