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

Category: Theory, studies

Academically published myoelectric arm control error rates since ~1980 remain extremely high, far above any real life use requirement, and not even a slight trend to more reliable control in sight: what does this mean?

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Academically published myoelectric arm control error rates since ~1980 remain extremely high, far above any real life use requirement, and not even a slight trend to more reliable control in sight: what does this mean?; published January 29, 2019, 19:00; URL: https://www.swisswuff.ch/tech/?p=9244.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Academically published myoelectric arm control error rates since ~1980 remain extremely high, far above any real life use requirement, and not even a slight trend to more reliable control in sight: what does this mean?}}, month = {January},year = {2019}, url = {https://www.swisswuff.ch/tech/?p=9244}}


I took the liberty to review published error rates for myoelectric arm controls since ~1980. In other words: how reliable is the myoelectric arm control? How has the reliability changed over years?

This is hard data that is somewhat impossible to negotiate, and it has always been there for anyone to take. So forgive me when I anticipated some clear conclusions from such information over the last years - after all, I figured, a post such as this would not run away ; ) Even though, you must keep in mind that you read this here first as well. As far as I know, despite its ubiquitous availability, and despite a very obvious background or social reason for this (which is yet another subject), this collection of data has not been formally performed before. In fact, word of mouth had it that even decades ago, no self respecting engineer would deliberately enter the field of myoelectric or robotic prosthetic hands, simply because of all options one could do, that certainly was never a prosperous looking one.

The reason for this subject choice is, that I was interested in possibly identifying a trend, or a useful figure, for the reliability of myoelectric arm controls to consider in context of daily use. I used standard key word searches on Google Scholar and edited the resulting publications for relevance. I thus performed more systematically what I had done anecdotally a few years ago when it became obvious that one should not put too much hope into such prostheses, as their ongoing and intractable issues were somewhat obvious all along - at least from view point of a right below elbow amputee performing real work.

Read More

Disability and the public - prosthetic arms and more: do we appear "competent"? (review)

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Disability and the public - prosthetic arms and more: do we appear "competent"? (review); published December 7, 2018, 15:50; URL: https://www.swisswuff.ch/tech/?p=8812.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Disability and the public - prosthetic arms and more: do we appear "competent"? (review)}}, month = {December},year = {2018}, url = {https://www.swisswuff.ch/tech/?p=8812}}


The current view of us, what the general public thinks of us, seems to be a major aspect. Of "us", yes.

The research question for this armchair analyst thus will be: are we - arm amputees in specific, and, as people with a visible physical handicap more generally, more broadly as disabled people generally, seen as competent people?

Generally, the answer seems to be a clear "NO" right from the outset.

This should not come as a shock. There are good reasons to believe that, great reasons to make that plausible, perfect reasons to justify that statement. With that, there may be exceptions to that -  people that see through society's fairytales of disability, horror and fears, but they are usually the exception.

As I had figured out quite early into my enquiries into that issue, that this aspect is of absolutely no further practical concern not because it is not disconcerting - but because I cannot change it. And that is a rapid, lean and cynical logical consequence, that I stopped caring about what other people think of me based on, say, visual impression of my prosthetic arm. I may thus safely focus on function and comfort, sustainability and cost, without worrying too much about whether other people treat me as more or less competent based on my looks. Not because it would not be cool to take influence but because it is of no matter as to the target dimension: the tendendy to disregard any mental capacity of people with physical handicap appears to be implemented in many people's thinking outside of any actual experiences. And regardless of what type of prosthesis I wear.

If anything, I might optimize my appearance by simply trying to look reasonably neat.

But to bend over backwards for what really we have to concede are actually strange people? If anything, can we hack their brains?

Read More

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_1573559837, 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.

Read More

3D-print molded Protosil RTV 245 (durometer shore 40A) silicone covers for Toughware Equilux [proof of concept, demo of "bionic" grip]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - 3D-print molded Protosil RTV 245 (durometer shore 40A) silicone covers for Toughware Equilux [proof of concept, demo of "bionic" grip]; published February 4, 2018, 11:50; URL: https://www.swisswuff.ch/tech/?p=8248.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - 3D-print molded Protosil RTV 245 (durometer shore 40A) silicone covers for Toughware Equilux [proof of concept, demo of "bionic" grip]}}, month = {February},year = {2018}, url = {https://www.swisswuff.ch/tech/?p=8248}}


It is sometimes more fun to present the technical results before or even instead of explaining exactly why.  So in short, I 3d-designed and then printed molds to make grip covers for really serious grip performance of a Toughware Equilux device.

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_1573559837, 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 performance enhancement through modifying terminal device gripper surface [overview]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Grip performance enhancement through modifying terminal device gripper surface [overview]; published July 19, 2017, 16:00; URL: https://www.swisswuff.ch/tech/?p=7431.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Grip performance enhancement through modifying terminal device gripper surface [overview]}}, month = {July},year = {2017}, url = {https://www.swisswuff.ch/tech/?p=7431}}


When using a prosthetic arm with a terminal device, grip performance is a key issue.

Usually, a bare steel hook such as the Hosmer model 5 works through just about every situation. That is just because that is how it is. A closer look reveals, however, that that view may be overly simplistic. If anything, it requires explanation.

Read More

Prosthetic hand and gripper options: grip analysis, grip construction [summary/post list]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Prosthetic hand and gripper options: grip analysis, grip construction [summary/post list]; published October 11, 2016, 12:36; URL: https://www.swisswuff.ch/tech/?p=6663.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Prosthetic hand and gripper options: grip analysis, grip construction [summary/post list]}}, month = {October},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=6663}}


This website features a range of posts regarding grips and both analytic and constructive aspects. Here is a short overview of the most relevant.

Read More

Liquid hands in a liquid modernity [symbolism, realism - and then what?] {rather graphic, viewer discretion advised, long, difficult}

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Liquid hands in a liquid modernity [symbolism, realism - and then what?] {rather graphic, viewer discretion advised, long, difficult}; published February 12, 2015, 17:56; URL: https://www.swisswuff.ch/tech/?p=4239.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Liquid hands in a liquid modernity [symbolism, realism - and then what?] {rather graphic, viewer discretion advised, long, difficult}}}, month = {February},year = {2015}, url = {https://www.swisswuff.ch/tech/?p=4239}}


Liquid identity and liquid hands

One might assume that the "value" or "importance" of hands os the same. It is not. Watch this. Everything these days is in motion. Things are not as they used to be. On second thought, try reading below ; )

Read More

iLimb Ultra Revolution - global news: a fitting work glove has been found [product tip]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - iLimb Ultra Revolution - global news: a fitting work glove has been found [product tip]; published May 25, 2014, 12:38; URL: https://www.swisswuff.ch/tech/?p=3072.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - iLimb Ultra Revolution - global news: a fitting work glove has been found [product tip]}}, month = {May},year = {2014}, url = {https://www.swisswuff.ch/tech/?p=3072}}


(Updated 10/2018)

Durability of iLimb gloves - given the overall iLimb's failure to really assist with hard grips [link] - is a bit of a joke anyway. Even though, prices are high for replacement gloves. Now, a work glove has been found that fits it.

This is global news as several user forums failed to elicit cogent answers. Also, a request to the prosthetist who allegedly had forwarded that problem to Touch Bionics also failed to elicit a useful reply. That means that, again, this website digs into uncharted terrain.

Again!?

Read More

Bioethik, Human Enhancement und Behinderung [am Beispiel Unterarmamputation rechts]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Bioethik, Human Enhancement und Behinderung [am Beispiel Unterarmamputation rechts]; published October 29, 2013, 06:49; URL: https://www.swisswuff.ch/tech/?p=2152.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Bioethik, Human Enhancement und Behinderung [am Beispiel Unterarmamputation rechts]}}, month = {October},year = {2013}, url = {https://www.swisswuff.ch/tech/?p=2152}}


Die Bioethik, auch in der Schweiz, versucht sich seit geraumer Zeit damit, den Begriffsraum des Enhancement, der "verbesserten Körper", begrifflich zu besiedeln. Gleichzeitig sitzen namhafte Vertreter der Bioethik in verschiedenen Gremien ein, in denen Patienten-relevante Entscheidungen vorbereitet und getroffen werden (Spitäler, Krankenkassen, Swiss Medical Board). Es wird also angestrebt, sich in der aktuellen Realität zu etablieren.

Dabei war es Bioethikern grundsätzlich bislang völlig  egal, was mit den Körpern von Behinderten passiert und gemacht wird - schlicht allein auch deswegen, weil das Terrain von aussen gesehen ja wohl fast völlig unwegsam sein muss und sich dem Zeitgeist jedenfalls nicht von selbst erschliesst. Vielmehr kümmerte man sich in der Bioethik erstmal um Rechte und Pflichten von Patienten und Ärzten allgemein, um Rechte und Pflichten von Forschern und ihren Test-Subjekten, woraus man klinisch-medizinische und forschungsbezogene Richtlinien ableiten wollte; dabei ergaben sich Fragen vor allem bei der Frage nach einer möglichst fairen Zuteilung knapper Behandlungsmöglichkeiten, oder etwa bei der Frage nach dem Umgang mit Retortenbabies. Bislang unbeleuchtet durch Bioethiker blieb sicher auch die Frage danach, was die Voraussetzungen sind, dass ein Armamputierter einem gewagten Forschungsprojekt zu dieser Behinderung überhaupt (aus freien Stücken) einwilligen kann, und inwieweit diese Einwilligung nicht freiwillig sein kann, sondern unter Druck geschieht. Dabei ist es besonders interessant, dass die Bioethik sich in alltagsrelevanten Abwägungen wie Armprothesen gegenüber chirurgischen Massnahmen zur Erreichung minimaler Greiffunktion sehr klar geäussert hat, während die nach meiner Ansicht bedeutend heiklere Frage nach dem Druck von aussen - gerade angesichts aktueller Entwicklungen - komplett unbeachtet bleibt.

Um die Körper sichtbar behinderter Leute kümmerten sich Bioethiker von ihrer begrifflichen Definition her weniger [1]. Soviel ist bestens bekannt. Bioethik wurde ja eben auch grundsätzlich vor allem für die wirklich wichtigen Fragen - also zur Eindämmung der Medizinkosten bei Fragen zu Hirntod,  Organspenden oder  ungeborenen Kindern - auf den Plan gerufen. Dass sie sich jetzt jäh echten und schwierigen, handfesten (!) und mit konkreten Erwartungen besetzten Behindertenthemen ausgesetzt sehen, denen aus ihrer Sache heraus Edelkeit, Ruhm, überhaupt philosophische Eigenschaften abgehen, hat seit längerem die Bioethiker wohl fast so stark entsetzt wie Interessensvertreter von Behinderten [2]. Wer aber hier beginnt, im Garten der Bioethik Behindertenthemen mit umzugraben, wird versehentlich den einen oder anderen Rohrbruch verantworten, denn zum verantwortungsvollen und vor allem sinnvollen und auch fuer Behinderte akzeptable Vorgehensweisen fehlen Wissen, Interesse, Erfahrungen und somit leider auch Respekt.

Denn bei allem Respekt vor dem Fach der Bioethik und deren effektiv tief greifenden, schwierigen Fragen, etwa um Geburten und Sterben - kein Mensch verfasst ethisch-moralische Traktate etwa zur Frage des Ersatzes defekter Auspuffe an Autos. Und hier geht es um ein hartes, alltaegliches Auspuffthema, in das die Bioethiker nun eben hammerhart hineinlaufen, wenn sie nicht aufpassen. Bioethiker sind dabei auch ausserordentlich kalt und rücksichtlos, wenn es darum geht, die Dinge zusammenzuschreiben, dass es ihnen passt, wohl schaffen es Autoren oder Herausgeber auch nicht, die nötige Kritik gegenüber den eigenen Texten aufzubringen; so schreibt etwa Frau Dr. Katrin Grüber [3] "Der Sprinter Oscar Pistorius kämpft seit Jahren darum, bei den regulären Olympischen Spielen mitlaufen zu können. Immer wieder fanden gerichtliche Auseinandersetzungen darüber statt, ob ihn die C-legs (C-Legs: mikroprozessorgesteuerte Beinprothesen der Firma Otto Bock, die nicht nur mechanisch das fehlende Bein ersetzen, sondern bei denen die Bewegung angepasst wird), die er trägt, zu einem unerlaubten Wettbewerbsvorteil im Sinne von Doping verhelfen." Dies ist in mehrerer Hinsicht selbstverständlich völlig falsch, und die Implikationen davon sind relativ wichtig. 1) Pistorius rennt mit Ossurprothesen, niemals mit Otto Bock; 2) Die Dinger sind Carbonfedern, sie leisten eine passive Federleistung, sie enthalten keine Elektronik, keine Kabel und keine Mikropozessoren, denn wer weit schnell rennt will auch wenig Gewicht rumschleppen; 3) Mikroprozessoren sind stromgetrieben; C-Legs benötigen Strom und erbringen im Sinne von Regelkreisen Steuerleistungen; das ist bei Oscar Pistorius' Blades nicht so; 4) C-Legs sind mikroprozessorgesteuerte prothetische Kniegelenke für Above Knee Amputations, aber Pistorius hat seine eigenen Kniegelenke, er ist ein Below The Knee amputee, so dass Pistorius gar kein C-Leg verwenden kann, da es sich dabei um Kniegelenke (nicht um Beine, wie das Suffix "leg" suggeriert) handelt. Weder die Behinderung von Pistorius noch die Prothesen sind in irgendeiner Weise adäquat beschrieben. Es fehlt umfassend am Sachverstand. Man darf hier umfassend kritisch sein.

Neuerdings geht es bei der Frage um "Human Enhancement" innerhalb der Bioethik und medizinischen Sachethik namentlich darum, dass Empfehlungen für Krankenkassen abgegeben werden sollen [4][link], die in der Schweiz nun generell und pauschal dahin zielen, dass "Verbesserungsmassnahmen" an "grundsätzlich gesunden Körpern" definitionsgemäss "keine medizinische Therapie" darstellen und damit nicht kassenpflichtig sind.

Es geht in diesen Texten um die Partikularinteressen einzelner Versicherer: wie machen wir den Beitragszahlern weis, dass sie aufgrund überragender Risikodeckung schöne Beitragssummen zahlen, um gleichzeitig möglichst wenig davon auszuzahlen? Wer das nicht erkennt, versteht das Wesen von Versicherungen nicht. Welche Begriffe - etwa "Human enhancement" - können widerspruchsarm über möglichst viele Lebenssituationen derart übergestülpt werden, dass daraus für die Versicherung ein finanzieller Vorteil erwächst?

Auch scheint ein Problem das Wort "Verbesserung" zu sein. Eine "Verbesserung" ist nach dem allgemeinen Verständnis am gesunden Körper unnötig sind. Diese Bezeichnung lässt ausser acht, dass ich einen "behinderten" gesunden Körper habe, und, dass dieser nicht "verbessert" würde, von "gut" bleiben wir weit weg. Er wird vielmehr etwas "weniger schlecht" gemacht, wobei der effektive Nutzen gesellschaftlich und individuell klar vorhanden ist. Damit kommt die Empfehlung der SAMW diesbezüglich verpeilt, schlecht ausgerichtet, daher.

Das übergeordnete Sozialversicherungsgesetz, sowie jegliche Betroffenenoptik (also etwa die Sichtweise Behinderter), bleiben bei diesem Geschäftsmodell logischerweise beiseite - klar, da einzelne Versicherungen ein Ziel haben, das nicht durchwegs den Interessen der Versicherten oder Gesetzgeber oder auch dem Interesse anderer Versicherungen entsprechen muss. Dies ja offenbar in einem derart hohen Ausmass, dass Verwaltungsgerichtsverfahren zur Klärung von Einsprachen Versicherter gegen Entscheidungen von Versicherungen in der Schweiz gratis sind. Missbrauch ist also offenbar aus Staatssicht zu erwarten. Nur, dass wir hier von einer fairen Verhandlung sehr weit weg sind. Ganz zwangsläufig werden daher Sichtweisen und Lösungsvorschläge resultieren, die nicht unbedingt konform mit dem Sozialversicherungsgesetz sind, die vor allem viel Geld kosten können, und potentiell die Betroffenen dennoch benachteiligen.

Praktisch und tatsächlich ist das auch so, und da bin ich von so einer Art Sichtweise unmittelbar betroffen.

Dies ist aber auch wieder theoretisch interessant, da durch die weder demokratische noch fachlich abgestuetzte Macht, die der Bioethik hier bei der Definition zur Grundlage weitreichender Entscheidungen gegeben oder zugeschrieben wird, ein wiederum messbarer Schaden entsteht bzw. perpetuiert wird, der auf keinerlei vorgesehene Weise mehr behoben werden kann. Auch nicht auf der Ebene des Verständnisses. Der Schaden ist unter anderem finanziell, und er ist ganz erheblich.

Das unmittelbare Ergebnis des Einflusses der Bioethik auf unser Gesundheitswesen ist aber zunächst, dass insbesondere operative (oder medizinische) Verfahren, die dem "Human Enhancement" zugerechnet werden, nicht von Sozialversicherungen bezahlt werden sollen. Gleichzeitig wird empfohlen, Human Enhancement - zu dem ebenfalls passive / kosmetische Armprothesen zu rechnen wären - auszusetzen.

Read More

[1] W. T. Reich, "The word" Bioethics": the struggle over its earliest meanings," Kennedy Institute of Ethics Journal, vol. 5, iss. 1, pp. 19-34, 1995.
[Bibtex]
@article{reich1995word,
  title={{The word" Bioethics": the struggle over its earliest meanings}},
  author={Reich, Warren Thomas},
  journal={{Kennedy Institute of Ethics Journal}},
  volume={5},
  number={1},
  pages={19--34},
  year={1995},
  publisher={The Johns Hopkins University Press}
}
[2] [doi] M. Kuczewski and K. Kirschner, "Special issue: Bioethics & disability," Theoretical Medicine and Bioethics, vol. 24, iss. 6, pp. 455-458, 2003.
[Bibtex]
@article{kuczewski2003,
year={2003},
issn={1386-7415},
journal={{Theoretical Medicine and Bioethics}},
volume={24},
number={6},
doi={10.1023/B:META.0000006925.05440.1a},
title={{Special issue: Bioethics & disability}},
url={http://dx.doi.org/10.1023/B%3AMETA.0000006925.05440.1a},
publisher={Kluwer Academic Publishers},
author={Kuczewski, Mark and Kirschner, Kristi},
pages={455-458},
language={English}
}
[3] M. Eilers, K. Grüber, and C. Rehmann-Sutter, Verbesserte Körper - gutes Leben?: Bioethik, Enhancement und die Disability Studies, Lang, 2012.
[Bibtex]
@book{miriam2012verbesserte,
  title={Verbesserte K{\"o}rper - gutes Leben?: Bioethik, Enhancement und die Disability Studies},
  author={Miriam Eilers and Gr{\"u}ber, K. and Rehmann-Sutter, C.},
  isbn={9783631630655},
  lccn={2013388648},
  series={Praktische Philosophie kontrovers},
  url={http://books.google.ch/books?id=MOOwMQEACAAJ},
  year={2012},
  publisher={Lang}
}
[4] N. Biller-Andorno, Medizin für Gesunde? Analysen und Empfehlungen zum Umgang mit Human Enhancement Bericht der Arbeitsgruppe «Human Enhancement» im Auftrag der Akademien der Wissenschaften Schweiz
[Bibtex]
@book{samw2012humanenhancement,
  title={{Medizin für Gesunde? Analysen und Empfehlungen zum Umgang mit Human Enhancement Bericht der Arbeitsgruppe «Human Enhancement» im Auftrag der Akademien der Wissenschaften Schweiz}},
  author={Biller-Andorno, Nikola},
  isbn={978-3-905870-29-9},
  url=http://www.samw.ch/de/Ethik/Human-Enhancement.html}

Manualization of the body and time and effort spent to implement it [options for people missing an upper extremity part]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Manualization of the body and time and effort spent to implement it [options for people missing an upper extremity part]; published September 11, 2011, 20:37; URL: https://www.swisswuff.ch/tech/?p=469.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Manualization of the body and time and effort spent to implement it [options for people missing an upper extremity part]}}, month = {September},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=469}}


If a part (or more parts) of upper extremities are missing, absent function can be replaced to a small degree.

Replacing at least some basic aspects of a hand's function with the rest of the body and immediate environment is what upper extremity amputees including myself do every day.

There are a few questions along the road, but other than that, "manualization of the rest of the body" as well as manualization of surrounding environment is what is going on. There are simply no other options and interestingly, problems are similarly in nature regardless of the type of solution one chooses.

When evaluating a prosthetic hand, when doing evaluation of a prosthetic arm or hook, when evaluating myoelectric or ""bionic"" prostheses such as iLimb, BeBionic or Michelangelo by Otto Bock, then this should be considered thoroughly.

Read More

What makes a good grip - gadget for non-disabled people [product]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - What makes a good grip - gadget for non-disabled people [product]; published April 10, 2011, 14:28; URL: https://www.swisswuff.ch/tech/?p=394.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - What makes a good grip - gadget for non-disabled people [product]}}, month = {April},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=394}}


Disability is a relative term, as it appears.

One may turn out to be disabled facing a certain task, and non-disabled facing another.

As it appears, seemingly non-disabled people cannot handle all of today's medical containers or connectors too well manually.

So, grip prosthetics enter the world of non-disabled people.

Matthew Ostroff developed Medegrip.

Read More

Grip geometry and prosthetic solutions analyzed - stump, Krukenberg arm and grip [what we really want / Sci Fi]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Grip geometry and prosthetic solutions analyzed - stump, Krukenberg arm and grip [what we really want / Sci Fi]; published March 26, 2011, 20:40; URL: https://www.swisswuff.ch/tech/?p=390.

BibTeX: @MISC{schweitzer_wolf_1573559837, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Grip geometry and prosthetic solutions analyzed - stump, Krukenberg arm and grip [what we really want / Sci Fi]}}, month = {March},year = {2011}, url = {https://www.swisswuff.ch/tech/?p=390}}


1 Comment

To grip well and with ease (as already investigated earlier here), the gripper parameters usually are constrained to reside along that diagram:

Heavy design

With a solid slippery gripper, a complex, heavy mechanism requires at least 5 fingers to stabilize an object in 3D space (if not seven). See left side of the x-axis of that diagram above: the harder the grip surface (metal, wood, plastic), the more fingers are needed and thus the more complex the mechanism will be. Advantages of slippery smooth hard surfaces are the possibility to clean them thoroughly, and their longevity.

Light design

With increasing surface friction, less fingers are required. A simple prosthetic hook just has two "fingers" and optimally, both grippers are covered with silicone tubing. Grip is just as good as a heavy complex hard surface hand - but construction is a lot less complex and the weight can be kept a lot lower (or at same weight, the gripper is more sturdy). See right side of that diagram just above.

For grippers at that end of the diagram (far right), it is worthwhile to note that despite gripping beauty, soft deformable high friction surfaces wear down and require replacement. I have gone through tapes or gloves as rapidly as one set a week. Then, you need materials you do not have to order through special channels that cost a fortune but are straight forward.

Caveat

Now, we are not free in our choices for everyday usage of a prosthetic. I recently learned of a ~ 7kg research prosthesis for robotic research of a multi-articulated prosthetic hand. The researchers could wear it for 20 minutes before their arms would start shaking.

Do NOT follow this link or you will be banned from the site!
HTML Snippets Powered By : XYZScripts.com
I footnotes
x2