So, apparently I had been "identified" as a "super prosthesis user" by a group of researchers. And I was invited to talk about embodiment in context of the "rubber hand illusion" at a user interface or robotic control workshop [link].
So is that what I am: a "user"?
This is a blog post of one of the rare focused and well based scientific journal articles that really explains how real work, body powered and myoelectric arms relate and go together for a unilateral right below elbow amputee in a physically demanding work environment.
The prior presentation of this paper [poster at Cybathlon symposium 2016], which had been more pragmatically worded (with me thinking people would know anyway), this was now written up as article and published. During that process, the reviewers clearly made great points of all kinds of aspects I never knew were not sky clear to everyone.
So maybe, writing a ~ 30 page case study with > 210 references does clarify stuff, at least potentially and for those that actually read it. But possibly, it still requires attention to even just read it.
Knowledge does not come easy, Highlander! (Nakano, in: Highlander III The Final Dimension)
If you are more interested in visionary posts, read about the gadget features of the prosthetic arm in Kingsmen: The Golden Circle [link]. And technically, myoelectric control did have it coming. That technology remained uncool for four decades [link].
Algorithm to chose best option for prosthetic arm, based on eight years of consecutive experience and extensive hard work.
Body powered arms are not the same. Despite everyone saying they understand what these are, these arms are not the same.
My setup explained, a generic setup explained. To show similarities and differences. For those in need to learn about this, technical differences to myoelectric arms are explained.
A useful development is presented here: new body powered socket and gripper technology primarily aimed at children.
This development appears to avoid the 'single individual or competitive company charging into patent market derailment with a stalled / stalling product'. The thing is that rare / orphan disease rules play out. It is not acknowledged by many but the clever players play by these rules, for sure. Because one thing is for sure - below elbow amputees are rare - only half wear prosthetic arms - about half of which are probably body powered. Those are so few out and far that economic laws of free markets neither work nor play out. With any new patented invention you won't change shit. Rather, people that use conventional marketing of their usually not too inventive products are responsible for stale product ideas and stale products, for immature developments and bad manufacturing. Commercial prosthetic arms are one big proof for the term 'stale' - look around and ponder. Patent applications are harmful and keep products or solutions from the market for another few years until - how so often - just about nothing really happens. But, not here.
The Delft University of Technology is a government supported institution that works on a whole line setup that appears to be well researched and solves actual problems. Solutions are published and made available. Great stuff.
Shoulder harnesses for body powered arms are used to pull open the terminal device (hand, hook). Using rubbers, springs or other elastics, the terminal device then closes. That is the most common way these prosthetic arms work. Terminal devices with that mechanism are also termed VO or "voluntary opening".
The force of the cable pulls on the strap, day in, day out. And it works well. Mostly.
After trying *a lot*  I started to wear a "cosmetic" PVC glove on my Becker Imperial hand. For some reasons this turns out to be almost perfect for a range of very non-obvious reasons for many situations.
 I tried silicone gloves, hooks, grippers, myoelectric, cosmetic, rubber covers, nitrile covers, leather gloves.
Increase of terminal device loading to a cable load of ~ 110N (~12 kg) has caused some issues. The cable housing so far contained a metal spiral and a silicone tube. These would rub on each other, and due to getting pressed hard the metal spiral would elongate and deform. Also, I wanted better control over pronation and supination.
Several attempts to remedy the situation have been undertaken.
Continuation from part I.
The final prosthesis now contains my latest selection of materials, mounted by my prosthetic technician. I find them widely available, affordable, comfortable, and easy to keep scent neutral.
I have a scar on my arm. I sweat. Our summers are hot. Sweat is normal. Air condition is not installed in many places. I work inside and outside the house, in the office but hopefully soon also back out doing cases on location. The harness and cable need to be protected with soft sturdy material that is easy to care for if not care free.