expletive-ethereal
expletive-ethereal
expletive-ethereal
expletive-ethereal

Category: Academic research with relevant results

Understanding and informing design issues of a prosthetic arm for below elbow amputation by way of "taxonomy" [literature review, reality check]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Understanding and informing design issues of a prosthetic arm for below elbow amputation by way of "taxonomy" [literature review, reality check]; published July 26, 2018, 21:18; URL: https://www.swisswuff.ch/tech/?p=7651.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Understanding and informing design issues of a prosthetic arm for below elbow amputation by way of "taxonomy" [literature review, reality check]}}, month = {July},year = {2018}, url = {https://www.swisswuff.ch/tech/?p=7651}}


The academic and industrial attempts to approach prosthetic arms so far have been met with less success than the providers must have hoped for. Far less, in fact so little that we wonder what is going on.

Possibly, design issues are the key to this as however vaguely put, some analytic approach needs to inform better design - but how to really inform better design from issues based on analysis? What is a suitable analysis? If we cannot see any better designs anywhere in practice, real life, then what is the analysis worth? Can we analyze analyses to get a better understanding of what might be going on there?

We might best start with what we know to be true.

Read More

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_1569216474, 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.

 

Read More

[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}
}

Grip planning and carrying out [TRS Prehensor vs. iLimb Ultra Revolution - theory and practice]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Grip planning and carrying out [TRS Prehensor vs. iLimb Ultra Revolution - theory and practice]; published October 17, 2016, 17:49; URL: https://www.swisswuff.ch/tech/?p=6764.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Grip planning and carrying out [TRS Prehensor vs. iLimb Ultra Revolution - theory and practice]}}, month = {October},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6764}}


To reliably plan and successfully carry out a grip using a prosthetic hand or gripper, it helps having a few requirements met.

This is obviously not clear at this moment, as recent experiences at the Cybathlon show. All the same, others and myself have addressed various related grip aspects previously so this is something we can come back to.

So let us start by watching the iLimb hand trying to grasp a clothespin.

Read More

Functional failures of prosthetic hands at the Cybathlon 2016 [details]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Functional failures of prosthetic hands at the Cybathlon 2016 [details]; published October 16, 2016, 13:23; URL: https://www.swisswuff.ch/tech/?p=7655.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Functional failures of prosthetic hands at the Cybathlon 2016 [details]}}, month = {October},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=7655}}


The Cybathlon 2016 was accompanied with publically broadcast video documentation of the event.

It is just not just as systematic as one would wish for a comprehensive research and development setting, but then, it was not an academic research event, but a publicity performance. But still, it contains a plethora of technical references.

Read More

#userdrivendesign Prosthetic arm design: i-Limb Revolution versus customized body powered arm in a work environment combining bodily exertion, wide temperature ranges, wide body motion ranges, heavy workload and subtle grips [Cybathlon Symposium, Oct 6 2016, Poster A12]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - #userdrivendesign Prosthetic arm design: i-Limb Revolution versus customized body powered arm in a work environment combining bodily exertion, wide temperature ranges, wide body motion ranges, heavy workload and subtle grips [Cybathlon Symposium, Oct 6 2016, Poster A12]; published October 2, 2016, 13:05; URL: https://www.swisswuff.ch/tech/?p=6342.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - #userdrivendesign Prosthetic arm design: i-Limb Revolution versus customized body powered arm in a work environment combining bodily exertion, wide temperature ranges, wide body motion ranges, heavy workload and subtle grips [Cybathlon Symposium, Oct 6 2016, Poster A12]}}, month = {October},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6342}}


PDF of poster presentation @ Cybathlon Symposium Oct 06 2016 @ Kloten.

Read More

Normalizing prosthetic arms and media: the role of 3D printing - official statement

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Normalizing prosthetic arms and media: the role of 3D printing - official statement; published July 7, 2016, 18:59; URL: https://www.swisswuff.ch/tech/?p=6226.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Normalizing prosthetic arms and media: the role of 3D printing - official statement}}, month = {July},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6226}}


It is intriguing that overly massive media pressure can bring proponents of new ideas in prosthetics to crawl back.

If, as typical in prosthetic arms since over 100 years (e.g., Carnes Arm, or, Russian Arm), "new products" are hyped up to no end, this can be a logical result: expectation and reality differences are stretched until a snap occurs.

Read More

Disability as spectacle? [tracing everyday experiences to follow this proposed aspect]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Disability as spectacle? [tracing everyday experiences to follow this proposed aspect]; published June 14, 2016, 19:37; URL: https://www.swisswuff.ch/tech/?p=6165.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Disability as spectacle? [tracing everyday experiences to follow this proposed aspect]}}, month = {June},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6165}}


An upcoming conference seems to hit more precisely than any other contemporary "spectacle" - from body "hacking" (featuring people that quite simply wear stock item devices) over "workshops" where participants are filmed or photographed (but do not get systematic solutions to all aspects that are shown) to "bionic" limb featurettes - the subject at the very core of the current preoccupation of society with disability is not help or support but focus. Support may only be part of making things appear right.

Actual, true, and dedicated improvement or help is not rendered. It is at best shown as sugar coating, thrown in as minimal excuse, offered as pretense, but not made a didactic or technical focus. We now need to delineate real work, real support from sugar coated symbolism that has different goals and purposes.

What is *featured* here - in that conference - is the "spectacle" aspect. What is featured in some odd "bionic" arm workshop is exactly that: they call it "help" - but they invite television to show how good they are and the focus is not on actual function but on "how it looks and appears to the public". They call it "support", but its main feature is a live stream of discussions on media channels all the while the hook remains the best prosthetic ever.

disabilityasspectacle

Read More

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_1569216474, 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.

Read More

Constraints in prosthetic arm research (literature review)

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Constraints in prosthetic arm research (literature review); published June 1, 2016, 12:11; URL: https://www.swisswuff.ch/tech/?p=6068.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Constraints in prosthetic arm research (literature review)}}, month = {June},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6068}}


A recent literature review  [1] lists apparent priorities and requirements for prosthetic arms. It mentions the fact that a prior literature review, dated 20 years earlier, already contained some of these requirements.

The necessary conclusions however are not presented; they really boil down to two reasons why that could be:

  • it should be evaluated whether the reasons given 20 years ago and again now just present excuses and not actual requirements;
  • it should be evaluated exactly who focused on practically resolving these issues through research or components, and why, possibly, they failed.
  • it should be evaluated inasmuch academic research now follows its own self-made "requirements" that, really, have absolutely no relevance in everyday life

Let us look at the research assumptions and these apparent requirements, point by point.

Read More

[1] [doi] F. Cordella, A. L. Ciancio, R. Sacchetti, A. Davalli, A. Cutti, E. Guglielmelli, and L. Zollo, "Literature review on needs of upper limb prosthesis users," Frontiers in Neuroscience, vol. 10, iss. 209, 2016.
[Bibtex]
@ARTICLE{cordella2016review,  
 AUTHOR={Cordella, Francesca  and  Ciancio, Anna Lisa  and  Sacchetti, Rinaldo  and  Davalli, Angelo  and  Cutti, Andrea  and  Guglielmelli, Eugenio  and  Zollo, Loredana},   
TITLE={Literature review on needs of upper limb prosthesis users},      
JOURNAL={Frontiers in Neuroscience},      
VOLUME={10},      
YEAR={2016},        
NUMBER={209},         
URL={http://www.frontiersin.org/neuroprosthetics/10.3389/fnins.2016.00209/abstract},       
DOI={10.3389/fnins.2016.00209}
}

Missing hand, hook, and perceived risk [sociology of fables leaking into modern day perceptions]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Missing hand, hook, and perceived risk [sociology of fables leaking into modern day perceptions]; published May 30, 2016, 22:40; URL: https://www.swisswuff.ch/tech/?p=4681.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Missing hand, hook, and perceived risk [sociology of fables leaking into modern day perceptions]}}, month = {May},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=4681}}


Fables and fairy tales carry narratives whose symbolism swaps over into apparently secular perceptions [1]. In other words, even societies that claim to be educated, enlightened and secular typically risk to follow myths - unless they take very specific care to not get trapped there.

Read More

[1] S. White, "Severed Hands as Symbols of Humanity in Legend and Popular Narratives," , 2014.
[Bibtex]
@article{white2014severed,
  title={Severed Hands as Symbols of Humanity in Legend and Popular Narratives},
  author={White, Scott},
  year={2014}
}

Electromagnetic shielding and phantom pain [tech corner]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Electromagnetic shielding and phantom pain [tech corner]; published May 23, 2016, 19:57; URL: https://www.swisswuff.ch/tech/?p=5981.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Electromagnetic shielding and phantom pain [tech corner]}}, month = {May},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=5981}}


Electromagnetic interference or EMI is supposed to contribute to phantom pain. We do not know why that is. Other theories attribute phantom pains to an efference/afference dysbalance. Apparently, mirror therapy works but not in all cases.

But, what do we know.

Read More

Graphene-based neural interfaces are a first promising method to interfacing directly with our nerves [science]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Graphene-based neural interfaces are a first promising method to interfacing directly with our nerves [science]; published February 26, 2016, 15:41; URL: https://www.swisswuff.ch/tech/?p=5712.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Graphene-based neural interfaces are a first promising method to interfacing directly with our nerves [science]}}, month = {February},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=5712}}


From [1]:

Connecting technical conductive materials - as in: wires - to nerve cells - as in: spine, brain, peripheral nerves - is important to develop prosthetic devices where interfacing surfaces should only minimally disturb the nerve cells and surrounding tissues.

starwarshand

Current materials are tungsten microwire electrodes or silicone based electrode arrays that represent a long-term trauma and that elicit a long-term inflammation. Typical long-term issues are the formation of an insulating tissue layer around the implanted electrodes, the so-called "glial scar". Not only is the glial scar with concomitant long term inflammation a health issue per se, also the SNR (signal-to-noise ratio) deteriorates until the electrode entirely fails.

Read More

[1] A. Fabbro, D. Scaini, V. Leon, E. Vázquez, G. Cellot, G. Privitera, L. Lombardi, F. Torrisi, F. Tomarchio, F. Bonaccorso, and others, "Graphene-Based Interfaces do not Alter Target Nerve Cells," ACS nano, 2015.
[Bibtex]
@article{fabbro2015graphene,
  title={Graphene-Based Interfaces do not Alter Target Nerve Cells},
  author={Fabbro, Alessandra and Scaini, Denis and Leon, Veronica and V{\'a}zquez, Ester and Cellot, Giada and Privitera, Giulia and Lombardi, Lucia and Torrisi, Felice and Tomarchio, Flavia and Bonaccorso, Francesco and others},
  journal={ACS nano},
  year={2015},
  publisher={ACS Publications}
}

Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim [research alert]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim [research alert]; published August 27, 2014, 12:30; URL: https://www.swisswuff.ch/tech/?p=3465.

BibTeX: @MISC{schweitzer_wolf_1569216474, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim [research alert]}}, month = {August},year = {2014}, url = {https://www.swisswuff.ch/tech/?p=3465}}


A new study [1] revealed that single-arm amputee front-crawl swimmers produce approximately 20% less propulsion (tether force) than able-bodied swimmers with comparable training backgrounds.

Dividing the world record for my disability (IPC S9) (0:54,21) by the non disabled world record over 100m freestyle (0:46,91), an excess time of 116% of the arm amputee Cowdrey compared to the non disabled Cielo results. With that, my own personal best over 100m freestyle (1:10,21) is comparable to a non disabled 47 year old swimming 100m freestyle in 1:00,34.

Generally, it takes me some 98% of the 2014 qualifying or standard time for my non-disabled age group's FINA World Masters championship 100m freestyle LC, while my handicap slows me down by 16%. So if you have no handicap and you swim 98%/116%, that is, 84% of your non-disabled age group's qualifying time, then you are just as fast as I am, relative to age and handicap. In other words, I am on par with male swimmers without handicap that swim 0:53,8 (aged 25), 0:54,8 (30), 0:55,7 (35), 0:57,8 (40), 1:00,3 (45), 1:05,8 (50),  1:10,0 (55), 1:15,1 (60), 1:22,7 (70), 1:32,8 (75) and 1:42,9 (80). Female comparative times are 1:00,7 (25), 1:03,3 (30), 1:04,9 (35), 1:07,5 (40), 1:12,5 (45), 1:17,6 (50), 1:21,8 (55), 1:26,1 (60), 1:34,5 (65), 1:39,6 (70), 1:51,4 (75) and 2:10,8 (80).

Read More

[1] C. J. Lee, R. H. Sanders, and C. J. Payton, "Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim," Journal of sports sciences, iss. ahead-of-print, pp. 1-8, 2014.
[Bibtex]
@article{lee2014changes,
title={Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim},
author={Lee, Casey Jane and Sanders, Ross H and Payton, Carl J},
journal={Journal of sports sciences},
number={ahead-of-print},
pages={1--8},
year={2014},
publisher={Taylor \& Francis}
}
Do NOT follow this link or you will be banned from the site!
HTML Snippets Powered By : XYZScripts.com
I footnotes
x2