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Category: Strategy, marketing

Embodiment of a prosthetic arm [reflections, thoughts, considerations]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Embodiment of a prosthetic arm [reflections, thoughts, considerations]; published September 16, 2018, 15:42; URL: https://www.swisswuff.ch/tech/?p=8513.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Embodiment of a prosthetic arm [reflections, thoughts, considerations]}}, month = {September},year = {2018}, url = {https://www.swisswuff.ch/tech/?p=8513}}


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"?

Tsk.

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Scientific approach taken for implementing a successfully marketable microprocessor-controlled knee - history of Otto Bock C-leg [lessons for prosthetic arms?]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Scientific approach taken for implementing a successfully marketable microprocessor-controlled knee - history of Otto Bock C-leg [lessons for prosthetic arms?]; published January 2, 2018, 15:10; URL: https://www.swisswuff.ch/tech/?p=7790.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Scientific approach taken for implementing a successfully marketable microprocessor-controlled knee - history of Otto Bock C-leg [lessons for prosthetic arms?]}}, month = {January},year = {2018}, url = {https://www.swisswuff.ch/tech/?p=7790}}


This blog post takes a few relevant observations, and assumptions, throws them up in the air and sees if they turn into sunshine.

  • If anything has brought us forward, it is also the ability to find relevant short cuts. We do not always have to invent the wheel when really we just want a variation of it.
  • If there is any acutal success story where academic research was required to leverage consumer market for a prosthetic limb, it is that of Otto Bock's C-leg.
  • If we can understand what the concepts are for getting a C-leg successfuly built, marketed and sold, we should be able to take generalized aspects of it to formulate success elements for prosthetic hands, grippers or arms.

Background

While the idea of a microprocessor controlled knee was created earlier [link], no marketable solution was available in due course. "In the early 1990s, Kelly James, an engineer at the University of Alberta, Edmonton, Canada, developed the C-Leg, the first leg with microprocessor-controlled swing and stance phases. Buying the rights from the university, he traveled around the world to interest prosthetic manufacturers in his invention ("A Leg Up," by Isabelle Gallant, U of A Engineer, Spring 2011). However, he didn't receive any commercial interest until German manufacturer Ottobock bought the patent in 1992 and launched the groundbreaking technology.".

Then, based on work betweeen 1995 and 1998, a doctoral thesis at the ETH Zurich described an intelligently, microprocessor controlled knee for above knee prostheses built from available and affordable materials [1].

That research was performed 1995 to 1998, financially supported by Otto Bock, and Otto Bock presented its first C-Leg in 1997.

The rest is history. If ever there was a leap in performance of prosthetic function, ever, it was the C-Leg. No prosthetic hand ever came close to achieving this level of success.

So this particular doctoral thesis seems to contain some possibly interesting ingredients worthwhile looking at. As any doctoral thesis here is public record, and a copy of it must be made available at the public library, I borrowed a copy for further information.

There are some other prosthetic developments, however, nowhere else is academic research anywhere near that successful as in the instance of the C-leg:

  • Otto Bock Michelangelo hand; the mechanism seems to come from American DARPA or other army research and probably was just built, the first glove was a great design work. So there is no analytical approach comparable to the C-Leg. It is too heavy, it does not work with prosthetic gloves really, it is not sturdy.
  • i-Limb: This cannot possibly have suffered too much analytical thought. The device looks more like it was born out of something else. While it does not always function as maybe intended, it is really lovable. It does not have a reliable precision grip, it is really weak, it tears up its paper thin gloves within minutes.
  • TRS prosthetics: Bob Radocy as end-user himself developed by far the greatest useful solutions. But they are not the result of extensive academic efforts, so they cannot be compared to the C-Leg. They are extremely good though and any analysis must start there.
  • Toughware PRX: These devices are extremely well made, mechanics wise - but we lack an analytical model that precedes the engineering there as well, comparing this to the C-leg approach.
  • Becker Mechanical Hand: Also the Becker hand was clearly built by someone with great practical and pragmatic understanding. No analytical effort of the magnitude of a C-Leg preceded it though.
  • Hosmer hooks: they came out of a practical development, no scholarly work appeared to be prepared for these either.

 

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[1] D. Zlatnik, "Intelligently controlled above knee prosthesis," PhD Thesis, 1998.
[Bibtex]
@phdthesis{zlatnik1998intelligently,
  title={Intelligently controlled above knee prosthesis},
  author={Zlatnik, Daniel},
  year={1998},
 school={ETH Zuerich, Switzerland}
}

What if Hugh Herr built prosthetic arms [development cycles, how to get better with engineering]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - What if Hugh Herr built prosthetic arms [development cycles, how to get better with engineering]; published June 5, 2016, 23:31; URL: https://www.swisswuff.ch/tech/?p=6156.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - What if Hugh Herr built prosthetic arms [development cycles, how to get better with engineering]}}, month = {June},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6156}}


The absolutely relevant key aspect about Hugh Herr is that a brilliant inventor and at the same time very demanding user can iterate the development cycles very fast and very well, whereas other projects not even make it to taking actual / real users into the close loop of development.

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What to do once your arm has mindboggling amounts of DOF but your stump can only address 2-3 ? [tech scifi stuff]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - What to do once your arm has mindboggling amounts of DOF but your stump can only address 2-3 ? [tech scifi stuff]; published March 8, 2016, 19:08; URL: https://www.swisswuff.ch/tech/?p=5779.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - What to do once your arm has mindboggling amounts of DOF but your stump can only address 2-3 ? [tech scifi stuff]}}, month = {March},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=5779}}


Currently, media are swamped with the display of what they call "phantom limb project" (really not the first time that someone uses "phantom" for a prosthetic arm; read about my Becker Phantom hand from 3 years ago right here). So apparently, some prosthetic technician spent major amounts of time trying to construct this computer game look-a-like arm to a degree where its user apparently considers that he is a cyborg with an additional "cyborg mother", as if prosthetic parts have parents, too. Yeah, and my website also has a "cyborg father". If you listen for him, you might hear him breathe, "...khhhhh-ccccchhhhhhhhh-khhhhhhh-czzzzzh...".

dvader

Where is Amber Case, when we need her.

Now, while that Metal Gear inspired prosthetic arm design worn by James Young certainly does not look like it is going to wreck major brick walls any time soon, they might explore entirely different aspects of such equipment.

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Social ranking wins over function for "bionic" hands [this & that]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Social ranking wins over function for "bionic" hands [this & that]; published August 25, 2011, 17:40; URL: https://www.swisswuff.ch/tech/?p=475.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Social ranking wins over function for "bionic" hands [this & that]}}, month = {August},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=475}}


The actual and real performance of "bionic" hands (i.e., simple myoelectric hands that now offer what Becker hands offered since many decades, which is, an adaptive grip) is not anywhere near cool.

  • They are known to break, assumedly at first sight,
  • They suck out batteries within as little as a few hours of usage.
  • They do not offer anything close to a reasonable pinch force.
  • They are more heavy than useful.
  • Recent price estimates for a "bionic" arm range from 60'000 US$ do 120'000 US$.
  • Their marketing sucks up all company funds that would be far better invested in long-term prosthetic function such as better body powered technology. Instead, short lived gadgetry is marketed that is of extremely limited functional and otherwise probably no orthopedic help at all.

One may not even be able open a bag of popcorn and I would suggest it is quite correct to state that one might be at least as disabled with a "bionic" hand than without one - with the difference of all that money gone.

Hints for this being a rather correct assessment are out and about.

  • For example, the actor that demonstrated the Otto bock Michelangelo hand recently here in Zuerich [link] did not at all keep a symmetric posture, nor did he put that anchor to any use, before his show had started - instead he pulled up the shoulder of his amputated arm that had the Otto Bock Michelangelo hand on it, and he grabbed the cables he was about to plug into a computer into his own mouth. All nice and sweet but I can do that without "bionic" arm.
  • It has also been claimed several times now that an iLimb should be very useful to type or to "hold a bottle". For typing, what does count is a good symmetric back, neck and shoulder postur. But it is rather obvious that typing with an iLimb will cause painfully elevated shoulders and abnormally twisted elbows whereas typing with a prosthetic hook is far more relaxed, precise, fast and healthy. Facts are clear here, let there be no doubt [link, re-posted from link].

Given that these facts are sky clear and that I know of exactly no one who would ask for a "bionic" prosthesis from a functional view point, there are two very noteworthy recent stories to read and to learn from:

  • [1] A Florida judge of compensation claims ordered an employer to provide a worker with the i-LIMB hand prosthesis and therapy to assist him with the use of the prosthesis. [link] [link] [reference: Bond v. Superior Mulch, Inc., 18 FLWCLB 95 (Fla. JCC, West Palm Beach 2011)]
  • [2] 14-year-old Matthew James sent a tongue-in-cheek letter to the head of Mercedes' F1 team asking for £35,000 (~$57,000) for a bionic hand, which they could brand like an F1 car. Mercedes' response? They made him "the most advanced prosthetic hand in the world". [link] [link] [link] [link]

What do we learn from that?

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Prosthetic Aesthetics [fairytales, myths and hypes]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Prosthetic Aesthetics [fairytales, myths and hypes]; published July 2, 2011, 12:46; URL: https://www.swisswuff.ch/tech/?p=448.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Prosthetic Aesthetics [fairytales, myths and hypes]}}, month = {July},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=448}}


Science Gallery's HUMAN+ exhibition

Now, panelists - rather than journalists - accumulate to distribute fairytales, myths and hypes of tales unknown and terror that pertain to the wide and apparently foggy waters of subjects such as prosthetic arms, prosthetic bionic arms, prosthetic bionic hands, prosthetic devices as such, and not just as scope pertaining to the iLimb and iLimb pulse, but also to the Otto Bock Michelangelo hand, the BeBionic and BeBionic v2 hand, the new Vincent hand and other new "bionic" hands that may surface.

Proponents are Prof. Dr. Bertolt Meyer, Stelarc, Lizbeth Goodman and Rachel Armstrong. Host of the panel is Science Gallery director Michael John Gorman.

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Established companies find that customers like TOTALLY different designs [market relevant developments]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Established companies find that customers like TOTALLY different designs [market relevant developments]; published May 29, 2011, 01:46; URL: https://www.swisswuff.ch/tech/?p=420.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Established companies find that customers like TOTALLY different designs [market relevant developments]}}, month = {May},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=420}}


It is not just that prosthetic part manufacturers find their business is a bit of a stalemate. After all, optical glasses - a form of prosthetic enhancement of our visual system - today is a thriving business that, as opposed to the prosthetic limb business, is fashionable, affordable, fun, honest and open, contains (at least in Switzerland) a relatively high price for the unit (i.e. 1 pair of glasses) and from then on free maintenance.

What made that happen? What can we see in the market, maybe in other products, that helps us drive the prosthetic market?

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Orphan Disease - term, significance, consequence [statistics and insurance rant]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Orphan Disease - term, significance, consequence [statistics and insurance rant]; published March 23, 2011, 13:17; URL: https://www.swisswuff.ch/tech/?p=388.

BibTeX: @MISC{schweitzer_wolf_1569140582, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Orphan Disease - term, significance, consequence [statistics and insurance rant]}}, month = {March},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=388}}


1 Comment

There exists such an entity such as Orphan Disease or Rare Disease. These are defined based on their prevalence related to slightly differing numbers:

  • Prevalence of less than 1 in 1'500 people (USA; Rare Diseases Act 2002)
  • Prevalence of less than 1 in 2'000 people (European Union; EUROPEAN COMMISSION for HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL  - Directorate C - Public Health and Risk - Assessment - C2 - Health information, PDF)
  • Prevalence of less than 1 in 2'500 people (Japan; Japanese law)

An estimate for our local prevalence can be assumed from a Norwegian study with upper limb amputees containing  11.1 persons per 100'000 population of which around 43% had a forearm amputation, effectively rendering prevalence estimates for below elbow amputees around 1 in 50'000 persons [1].

With that, below elbow amputation issues share some rather interesting characteristics with issues of other orphan diseases that I find worthwhile mentioning.

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