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Current bionic prosthetic research including sensory feedback - simulacra, not simulans.

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Current bionic prosthetic research including sensory feedback - simulacra, not simulans.; published December 29, 2009, 17:14; URL: https://www.swisswuff.ch/tech/?p=253.

BibTeX: @MISC{schweitzer_wolf_1571422960, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Current bionic prosthetic research including sensory feedback - simulacra, not simulans.}}, month = {December},year = {2009}, url = {https://www.swisswuff.ch/tech/?p=253}}


Current 'prosthetic' academic, industrial and military research ignores body powered technology and design of a body powered mechanical stable and proficient hand grip for the most part (notable exceptions see below).

That of course is nothing but negligent from point of view of the many users that depend on such systems. There are far more pressing problems that prosthetic academic, industrial or military research could care about than bionic high tech such as bionic sensor feedback systems. And that in particular,  as if even these miss the mark by far.

So obviously, current academic, industrial or military prosthetic projects - such as: myoelectric "bionic" arms with sensory feedback - are not geared towards users but may just represent meager attempts of a society that is largely detached from their disabled members, and through such gadget activism that society tries to "feel good about themselves".

"Look how much we are doing for you". By and large, they are not doing that for us but for the most part they are probably doing that for themselves. Gadget technology is always nice and cool. But is it necessary or even helpful for an amputee that lacks part of an arm, and that can see?

A key question is: is a particular project 'real upper extremity prosthetics' at all?

Ask yourself this simple question (assuming you are an upper extremity amputee): "When I go and do everything necessary to buy, prepare and eat breakfast, will this piece of [prosthetic research item] provide invaluable orthopedic support for my body powered arm?"

If the answer is a clear 'yes' here, you may be dealing with real upper extremity prosthetics. The Becker Lock Grip hand or the V2P Prehensor clearly are such products.

If the answer is not a clear 'yes' but more an 'um' or even a 'no', then you are dealing with something else.

Then you may be dealing with society's feel-good program. Or a clever business idea. Or you may be dealing with a clever excuse for information technology engineers to have some fun.There is absolutely nothing wrong with that but don't call it anything else. If people such as Geoffrey "Peter Pan" Ling of the Revolutionizing Prosthetics program call body powered arms "something out of Peter Pan", they prove absence of awareness, technical understanding, respect and knowledge to a degree that seals the issue right then and there. That then, is anything but real upper extremity prosthetics. It's media entertainment, it's science fiction, it's great story telling, it's model ship construction for adults and it certainly seems to beat fishing - but it is not what I call prosthetics.

Magritte painted below the pipe "This is not a pipe" (Ceci n'est pas une pipe), which seems a contradiction, but is actually true: the painting is not a pipe, it is an image of a pipe. It does not "satisfy emotionally"—when Magritte once was asked about this image, he replied that of course it was not a pipe, just try to fill it with tobacco.

So our society sinks large sums money into simulacra - a cultural manifestation and proof of their harsh difficulties in productively acknowledging and respecting amputees, listening to them as if they were adults of capable judgment, and in providing better technical solutions. We are not living in a world that has people examine issues up close. Much rather, Planet Simulacra (a complex imaginary type of concept world) is navigated and real issues are efficiently bypassed.

Jean Baudrillard nicely discriminates simulans from simulacra:

The simulacrum is never that which conceals the truth -- it is the truth which conceals that there is none. The simulacrum is true. -Ecclesiastes

If we were able to take as the finest allegory of simulation the Borges tale where the cartographers of the Empire draw up a map so detailed that it ends up exactly covering the territory (but where, with the decline of the Empire this map becomes frayed and finally ruined, a few shreds still discernible in the deserts - the metaphysical beauty of this ruined abstraction, bearing witness to an imperial pride and rotting like a carcass, returning to the substance of the soil, rather as an aging double ends up being confused with the real thing), this fable would then have come full circle for us, and now has nothing but the discrete charm of second-order simulacra.

Abstraction today is no longer that of the map, the double, the mirror or the concept. Simulation is no longer that of a territory, a referential being or a substance. It is the generation by models of a real without origin or reality: a hyperreal. The territory no longer precedes the map, nor survives it. Henceforth, it is the map that precedes the territory - precession of simulacra - it is the map that engenders the territory and if we were to revive the fable today, it would be the territory whose shreds are slowly rotting across the map. It is the real, and not the map, whose vestiges subsist here and there, in the deserts which are no longer those of the Empire, but our own. The desert of the real itself.

We live in a world that has no concept that 'fake' watches are fake from the moment the misconception of there ever being a more 'real' watch occurs. We pay hundreds of thousands of dollars to research projects that advertise prosthetics but are anything and everything but prosthetics - and that will never deliver kick ass grip power to the user nor pave the way for such kick ass power in any future. They lack analysis, knowhow, ignore previous works, don't treat real problems but instead represent a world in itself that has no real basis, not even a remote connection to reality: instead, there is a hyperreal.

The immediate consequences of these well-established and deeply encrusted structures are these:

  • Complete lack of modern products in prosthetics. In fact, most current big companies that produce prosthetic components (Hosmer, Otto Bock) sell 1930's technology for body powered arms and 1970's to 1990's technology for myoelectric arms at dream prices.
  • Complete lack of funding for research into modern prosthetics. I have defined the term prosthetics above. Read again if you have to. The research money that should go into prosthetics is used up for gadgets, for robotics, for cool tinkering - but not for prosthetics.

If this was not the situation in prosthetics in the last 50 years, don't you think we'd know that by now?

Bionic prosthesis research working on sensory feedback builds on the premise that (1) I have no sensory feedback, (2) that sensory feedback is good, and (3) that the type of sensory feedback that is researched and built is then going to be useful and last but not least that (4) one day we will see an improvement.

Assumption 1: Current 'bionic sensory feedback' projects assume I have no sensory feedback whatsoever. Do these people study prosthetics at all? Whom do they ask? How deep to they dig?

I wear a pin lock system. My stump is rigidly rigged to the socket. My wrist is Ramax steel, and the connection to the terminal device is as stiff as we could get it. Any minute vibration is transmitted to my stump. So not only do I feel pressure, vibration and other blunt force, I also have a rather good feeling of a rough position in space. So I can type partly without looking at the keyboard, for example. In other words, I already have sensory feedback without any new age research. That is not so much the case with rubber parts such as Otto Bock's prosthetic hands. These definitely dampen vibrations and are quite soft. But why wear these unless you require that type of vibration control?

Apparently many amputees say they lack sensation in the prosthesis. But people will want to walk around without prostheses, wearing no artificial arm for any reason. One reason is to air the skin because quite frankly there's some build-up underneath the prostheses. Secondly the body image is warped and so why not "be myself version B (missing an arm)" versus "being myself version C (wearing prostheses)" at any given moment. Thirdly prostheses simply suck functionally - but as the is considered unacceptable news the truth is not offered but concealed. And there are other reasons that lie beyond this website to explain. Ever so often the correct answer may be 'uh, just because'. And explaining that type of thing is tedious, it may be considered ungrateful or impolite, and non-amputees tend to not get it. If someone asks me why do you not wear your arm, do I say 'to air out the stink'? 'to get relief from the prosthetic crap that I was given'? do I say 'it's my choice but in fact I did not reflect that question so I would not be able to verbalize an answer'? Instead it is a lot easier to say "I do not wear the prosthetic arm as it gives me no sensation feedback". That may just not be the reason but it sounds plausible. It's just that these answers may not make for such relevant research hypotheses as assumed from the outside.

Assumption 2: It is assumed that sensory feedback is good. And there is no clear 'yes' to this assumption.

With my arm, absence of too much sensory feedback is a good thing for my stump as it keeps phantom sensations and phantom pain low. One of the main problems before my amputation was severe chronic pain. Still now, minute triggers can start strong phantom sensations and pain. Such triggers include stump trauma. So, keeping my arm safe and protected from sensory input such as scratches, bangs and other indicators of close physical reality is a main feature of my prosthetic socket.

Secondly, ramming a tool or hook against a rough surface, using it to turn meat on the grill or to get pasta out of boiling water - not having to feel all details is a great feature. This type of absence of feeling requires no remedy. Au contraire, it is a technical advantage. So absence of sensory feedback can be functionally good.

Assumption 3: The type of feedback that is being built is going to be useful to solve real problems. Not true. I can most definitely solve the problems very well without that type of extra sensory feedback.

There *are* situation that require clear feedback. But I seriously doubt these situations will ever see a satisfying resolution via sensory feedback. Much rather, visual feedback and different problem solving strategies is what is really needed. These situations include:

  • Getting one bank note (rather than two) out of a wallet.
  • Grabbing small items from my jeans pocket.
  • Grabbing one piece of sliced bread (rather than more) from a bag.
  • Complex 1-hand-tricks such as operating a wrist band lock, doing complex multi touch track pad motions for operating a mobile phone, opening or closing buttons, finding the coin with the right size among different coins by feeling, etc

Those are clearly the moments that require feedback.

They are best solved by not using the prosthesis but a real hand. If not, at least a visual check is important. If that is not possible, a different situative layout is in order (i.e., carry bank note not in wallet but presort them and wear in a particular pocket; do not put small items into jeans pocket to begin with).

Assumption 4: If these guys are doing so much research, one day you will have a benefit is a completely faulty assumption. If it was for many of the research projects, you could way until doomsday.

From the website of the Advanced Robotics Technology and Systems (ARTS Lab): Over the course of its 15 year history, the ARTS Lab has built and consolidated a vast wealth of knowledge and skills in fields of biomechatronics, artificial perception, sensorial devices, automatic control, autonomous robot behavior programming, biomedical signal analysis, telematics, neuroscience and techno-ethics. Yet in the last 15 years, not a molecule of that apparently vast innovation has made it to the market. Conversely, the most bionic, finely graded and optimally tunedest technology I actually can use is the Ballif cable from back in good old 1812 (almost 200 years now). Doesn't you strike that as at least mildly odd?

What really is needed is not sensory feedback. Later maybe, much later - but for now, what really is needed is:

  • A. Research and development into new high quality cable control terminal devices with a 'halfways useful' (for prosthetic manufacturers that spells out as 'ultra extreme') gripping performance.
  • B. Research and development into new state of art mechanical body powered hands that are 'halfways useful' (for prosthetic manufacturers that spells out as 'ultra extreme superbionic haptic megatouch').
  • C. Research and development into new cable control setups that provides 'halfways useful' (for prosthetic manufacturers that spells out as 'extreme ultra') stability and performance.
  • D. Research and development into new compatible components such as pin lock and wrist units being 'halfways' compatible between different manufacturers (for manufacturers, that'd spell out as 'ultra compatible X9' or so).
  • E. Research and development into new appearances and designs of body powered prosthetics that is 'halfways acceptable' (for manufacturers, that'd spell out as 'mega sleek', 'ultra fashion', 'transformer generation', 'clic stick' or 'extreme de?!gn').

These are harder to come by though. In fact, close to impossible.

Good mechanisms don't fall from the sky, as it appears. Let us see who works on these:

A (terminal devices) B (hands) C (cable) D (compatibility) E (appearance)
Otto Bock No. No. No. No. No.
Touchbionics (iLimb) No. No. No. No. No.
Advanced Robotics Technology and Systems (ARTS Lab) No. No. No. No. No.
DARPA (Revolutionizing Prosthetics program) No. No. No. No. No.
Physionetics (V2P) Yes. - Yes. - Yes.
Becker Mechanical Hands - Yes. - - Yes.
MDP Meili (MSM wrist) - - - Yes. Yes.
Mark Lesek (Carnes/Becker redesign) - (Yes.) - (Yes.) (Yes.)

Categories: Science fiction

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