Feeling with a prosthetic “bionic” hand [research review] II

I had participated in an experimental sensory feedback trial [1-s2.0-S0028393213004144-main]  [1] primarily conducted by two of the authors, a while back. In autumn 2009, to be exact.

Incidentally, I now found the publication on-line, in 2014, to be exact. The researcher, despite me writing several mails (like, in 2010, or, 2011), did not find it necessary to inform me of the publication. The author list contains Francesco Marini, Chiara F. Tagliabue, Ambra V. Sposito, Alejandro Hernandez-Arieta, Peter Brugger, Natalia Estévez and Angelo Maravita.

I guess in research with arm amputee test rabbits such as me, not everyone owes the other one respect. This is living proof why signing up for trials may be total nonsense! Respect may be low, return may be zero, and all we are left with are cryptic riddles and writings beyond reality. Not universally, no, there are really laudable exceptions.

So here, as research test rabbit, further information went lacking. So then, I might just reciprocate this attitude and level of respect. What about a bit of a review about this bit of writing.

I mean, after all, they do complain about amputees not signing up for trials. Do we not wonder why!

Me as research test rabbit for sensory feedback

I was to sit down to use myoelectrodes to control an experimental prosthetic hand in the laboratories of the Artificial Intelligence institute of the University of Zuerich.

The hand was rather unstable, control wise. Actually, it was a total mess. Whenever a person called on the telephone, for example, the fingers would flutter. It was that bad. So I suggested they not use that phone there, which improved stability by a subjectively estimated 80%. That means, flutter went from total catastrophe to catastrophe (but not total). In fact, later, I decided to address that issue myself (see Visual Note in JOFRI, 2014). But that was before that.

In addition to control electrodes that had been placed on my stump to attempt to open or close the hand, they connected feedback electrodes to my upper arm to convey some sort of buzz. This then was the "sensory feedback". Depending on some aspect of grasping an object, and derived from some sort of sensors on the prosthetic hand's fingers, I would get buzzed there.

That ended in a mess.

My way of dealing with phantom pain is by mentally suppressing it. With the increased activity and buzzing and all, it seems that my brain started to increase the pain threshold and suppressed also the buzz feeling.

With that, the buzzes also became more distant, and all pain, including stump pain, phantom pain, was felt less intense, as well as the buzz signals that should have provided sensory feedback. With that, also nociceptive pain from increasing overuse of the tendons became more distant.

So far so good, they just turned up the buzz signal a bit using their electricity control knob, so it would still get through to my brain.

After that continued for a while, my stump started to get red at the end. That was where the tendons would run over the bone ends which happens when giving an open or close signal by contracting the stump's flexor or extensor muscles where the control electrodes were placed.

And my tendons and muscles were not used to that much, not used to that fast, and not used to that many motions, at all. I actually ran into serious overuse of that part of my damaged arm.

However since I was in the automatic mental process of continuously down regulating pain perception, something that my brain "just did", that slipped my attention altogether.

Until the day came when the pain suppression had reached some sort of limit.

Then I experienced screaming phantom pains, severe stump pain also from overuse, and the buzz started to hurt too, as mental pain suppression collapsed, and I was not able to continue any more. So at once, mental pain suppression stopped to work and overuse incurred damages plus all that came from it got really, really bad.

So summarizing what happened, the buzz and the unusual activity with tendons being ripped over my stump bone ends caused me a collateral increase in phantom pain.

As my brain automatically downregulated all types of pain and buzz perception, to mentally suppress that pain, I also reduced buzz perception. To remedy that, buzz levels were turned up by the researchers that kept asking me "can you feel the buzz?" (no) by increasing the electricity on their buzz electricity device. My brain, as it did by itself, pushed that away too. That allowed higher phantom and overuse pain levels from the stump to pass under my radar, running up considerable overall problems with my bone end and tendon area.

So I told the researcher that pains had increased suddenly, explaining how that had come about.

The researcher did not really believe it, as she said "it could not be". After the researcher then consulted a neurologist that somehow was on the research team too, that research person then changed her opinion to that my pains "could be after all". So, they pondered whether I made it all up! Which to me was weird as I am still not sure how many researchers they needed to ascertain to themselves or each other, that overuse and phantom pains "could" or "could not" be. Ultimately, the researchers set up a meeting with some orthopedic surgeons, I explained it to them, and after these concluded "this could be", they felt as "that could be" and that after all I was maybe right.

At any rate, buzzing feedback became part of what my brain did NOT want to feel real fast. I still feel the same about it.

Currently, I would opt for the "non-sensory-feedback" prosthetic arm, also if it was more expensive than the one with sensory feedback. In other words, I would pay for *not* having that thing that they now tried to figure out and build and research.

As my stump is something of a jelly bone type pain cake anyway, with constant phantom pain, phantom sensations going strong 24/7, cold temperature due to circulation problems, just wiggling that stump a little bit will be more than enough feedback already.

It is not that I have no sensory feedback, too. That is a myth these researchers must swap amongst each other, building on silly excuses of arm amputees that are not wearing their prosthetic arms. Wearing a hard socket with a body powered hook, I can feel tiny bumps against surfaces with amplitude, I can type without looking, I can drive my car, to name a few examples, and I do not know why I would need this buzz type extra sensory feedback boost.

Maybe that could be sensible once grasp ability is so finely tuned that my fingertips need to differentiate the sensory feedback of one against other coins in a pocket, or, of one against several bank notes in a wallet.

But prosthetic arms, hands, fingers are far from that.

And then, the sensory real estate necessary to up-link a usefully large array of sensors to the brain is massive, so I feel that it will be 300-500 years* before we see anything like it.


* 300-500 years: anyone has been predicting insanely unimaginable things to a time 10-20 years from now. Like, health policy lobbying for arm amputees. However if you raise your kids after yourself, and as you weren't able to think it up either, how and why should they do it? So, think about that. This is for entirely new generations after us to solve. We will never live to see this, ever. Be reasonable. Glad we talked about it though.

Paper review Marini et al. (2014) Crossmodal representation of a functional robotic hand arises after extensive training in healthy participants

I now cite text blocks from that paper [1] that I subsequently comment on.

What role does an absent limb give others to do stuff, think stuff? From the outset and into the dark, without even so much as considering, leave alone knowing these people, I know that if there is not any darned good explanation, it can mess them up quite a bit.

And so with great reluctance do we approach this text.

The absence of a limb, whether acquired or congenital, dramatically limits our interactions with the outside world. [1]

The absence of my right hand and forearm limits me to a degree, sure, but not overly.

I can still - and these are just a few examples - chase and photograph some rare Mediterranean jellyfish [link], refurbish cupboards [link], not just legally drive an unmodified (to adapt to my handicap, that is, otherwise that car does contain a MOPAR performance tuning) Dodge Magnum but also tweak and reprogram some OEM keys [link], mcgyverize and fix an Ikea lamp that is beyond reasonable repair [link], and many many other things (all also if not mostly without any prosthetic, mind you). I also build and test my own prosthetic stuff, having realized that academia leaves us alone for the most part. So, my ability to interact with what these folks call "the outside world" is not dramatically limited. That, in essence, is a totally wrong research premise.

So much for thinking and, worse, writing, that I am dramatically limited in my interactions with the outside world. Or people with a similar handicap.

If anything is dramatic, then it is the hype others put into this. That hype however is hard to downplay.

The correct statement thus would be, that amputation and absence of a limb can make other people nervous, and that per se has the capacity to reduce their cognition just at any given moment.

But isn't that their problem? And not mine.

Sure you could be hard boiled and cynical and make that my problem. And when I am in my social mood then I will agree to the "victim is the culprit" play do. And then I will wear a run of the mill cosmetic plastic arm, while strangely enough, everyone is still not happy. Then the usual double binds will be brought forward (A: you must hide your disability because it frightens others, B: you cannot hide your disability but you have to openly display it in order to show that you are honest and upright and forward).

Dramatically limited in my interactions? With the outside world? Look at it like that. Was I "dramatically" limited to interact with the "outside world" you surely could be safe from mildly irritated reviews like this.

People with "dramatic" limitations contain those that are maybe limited to using a speech computer, or people with Lou Gehrig's disease, people that are at once deaf, blind and that cannot speak, or people that do not master a language. Even severe cases of being unable to write or read fall under these. There I would go as far as calling their interactions dramatically limited.

These people that wrote up that article honestly believe that absence of a hand and a wrist dramatically limits my interactions with the outside world. That, besides using the term "healthy" to denote two handed people, tells us a lot more about what type of humans were are dealing with here, than they probably ever wanted to admit.

Damn, guys. Seriously. Reconsider.

In the rehabilitation of people who either underwent limb amputation or suffer from congenital limb deficiency (complete or partial absence of a limb since birth; Gold, Westgate, & Holmes, 2011), the use of artificial and prosthetic limbs plays a leading role (Fraser, 1998). [1]

My guess is, vocational counseling, pain management and antidepressants do play the leading role. Other stuff may follow.

The use of artifical limbs may in fact be very important for lower extremity amputees. For arm amputees? Do you believe that academic research (the stuff you all seem to tinker with) made it into everyday use, leaving alone to the point where it plays a leading role? You want to maybe start discussing your "research premises" with me?

Super satirical. Utterly funny. The stuff real comedy is made of. Seriously,  what absolute nonsense.

If anything, my light weight and material wise ultra modern, mechanical body powered arm that really helps keep overuse down, is quite important to me. Leading role, no. It has its moments where it shines. But you would not know anything about that, really.

Although these technological supports are often capable of replacing some functions of the absent limb, they sometimes provide imperfect solutions (e.g., Murray, 2004). [1]


What did these authors smoke or sniff? From the context - "technological supports (..) sometimes provide imperfect solutions" - they must have considered that some other times, prostheses do provide a perfect solution.

Again: some other times, prosthetic arms provide a perfect solution??

If anything, this sentence sets research apart from the real world yet again: these people live on another planet, or they are bat shit crazy, and that is the polite way of saying it.

Prosthetic arms totally excel in being absolutely imperfect. They are anything but perfect, always, 24/7. The degree of their imperfection ranges between The Absolute and The Ridiculous. Always.

Medical communities working with people who use prostheses often point out the need to transform the feeling relative to an artificial limb from that of an “inert supplement” or an “extracorporeal structure” into that of an incorporated, comfortable and efficient body part (Scarry, 1994). In this regard, some intriguing results have recently been obtained after the development of functional prostheses. Using the exciting technique of targeted reinnervation (see Kuiken (2006), for review), patients can control the movements of a robotic prosthesis as well as receive somatosensory feedback from it through redirected peripheral nerves that once mapped the territory of the missing limb (Kuiken, Dumanian, Lipschutz, Miller, & Stubblefield, 2004). On the sensory side, a sense of touch has been implemented by using a robotic tactile interface (G10 tactor) that is connected to a skin region innervated by redirected nerves ( Marasco, Kim, Colgate, Peshkin, & Kuiken, 2011). In this way, when the reinnervated skin receives any input from the prosthesis, amputees experience a sensation comparable to a realistic stimulation of the absent limb ( Marasco, Schultz, & Kuiken, 2009). Moreover, the same group ( Marasco et al., 2011) reported that two amputees who underwent targeted reinnervation had developed a sense of ownership ( deVignemont, 2007) towards the artificial supplement as assessed by means of several concurrent independent measures (self-report of patients' sensations during the experiments, questionnaires, psychophysical temporal order judgements, physiological temperature measurements). A very recent technical development in this line of research has been also reported by Micera (2013), whose low-invasive intraneural electrodes system allows amputees to re-establish a bidirectional flow of information between the subject's nervous system and the prosthetic device, thus ideally promoting the acceptance of the prosthesis itself as a body-like part. [1]

Yes. Sure.

But why go as far as confusing gadgetry with ownership? And to confuse feedback with feedback? Because people will think that they own a simple rubber arm [2].

And I am perfectly able to "own" my body powered hook that also gives positional and crude mechanical feedback - more than enough for me, as my stump is a bit of a pancake jelly. My hook is lightweight, its center of gravity has excellently low elbow torque, it is very fast and very reliable. It wins over many other options. It looks questionable if not curious, admitted - but so do all other options! If you believe you can leave any better impression with that robot hand throwing permanent jerks and fits and weird loud sounds, think again.

Furthermore, targeted reinnervation brings on problems by itself. These problems also influence, negatively from where I am standing, the degree of ownership. One anecdotal report about targeted reinnervation conveys that the prosthesis is pretty cool if (and only if) the prosthetic socket is aligned perfectly on the body. But it is not aligned perfectly most of the time. So it does not work, most of the time. And then, we do not know details about it, but tragically, one prominent targeted reinnervation patient recently committed suicide.

If any degree of ownership should really be attempted, it is the amputee feeling like they own their amputated body. That is the really hard part. Then build a prosthesis that does not hurt [link] and that helps prevent the worst aspects of overuse [link]. Then you have achieved a lot more than can be expected. Then you did real good. Only: that was the problem for the last 100 years, no one solved it, and there are hard reasons for that. Also that is difficult.

"Once you start wearing weird looking shit, you may as well go for best comfort and function" (Wolf Schweitzer, Red Hand pioneer, circa 2009).

The above evidence nicely shows that an artificial limb can be felt as part of one's own body after appropriate and congruent sensory stimulation. [1]

Ha, ha. I did not feel a particular ownership to that unreliable piece of wiggly engineering of your robot hand there, really. I believe also, that ownership has to be earned. I do not just adopt any piece of crap, bluntly put.

Also, a degree of ownership can be had without all that feedback stuff. Just set up a good study to compare that with different prostheses. On second thought and considering how y'all conducted yourself with this study, eh, don't.

Conversely, the lack of sensory feedback of less evolved kinds of prostheses, such as myoelectric devices, is often reported as a major drawback, which dramatically limits the usability and the acceptance of the prosthesis by the patient (see Lundborg and Rosen (2001), for a review). [1]

Haha, I am sure you are dying to know what real major drawbacks of myoelectric prostheses might be?

Just find the site map of this website and surf around a bit. Maybe you can find some interesting information. One can never be sure about the stuff others see, but why don't you try.

Eight subjects (mean age±standard deviation: 26.2±3, 4 females, 8 right-handed) participated in this experiment. Six of them participated in the experiment at the University of Zurich and the remaining two at University of Milano – Bicocca. All participants had normal or corrected-to-normal vision, were naïve as to the objective of the study and gave their informed consent to take part in the study. The study was approved by the ethical committees of the University of Zurich and the University of Milano – Bicocca, and it was conducted in accordance with the Declaration of Helsinki (World Medical Organization, 1996). [1]

You know, the title said "Crossmodal representation of a functional robotic hand arises after extensive training in healthy participants".

Now, I am disabled or maybe manually challenged.

But I am healthy as I can be. Hell, for all I know I may be healthier than any of the authors of the study. Health does not cover the presence of absence of a hand - unless I injure myself, unless I run into chronic overuse (which incidentally is something also two handed or two armed people may) or get ill otherwise, I remain healthy.

So it is really not possible, from their text, to see how many hands or arms the participants had.

For such a study, it is a major achievement to totally conceal that fact from the readers.

We hypothesized that an extensive and active training (but not a mere passive exposure) with a functional prosthetic limb by limbed participants would lead to the development of a crossmodal representation of the peri-limb visuo-tactile space, as assessed by means of the CCE, which is widely accepted as a reliable cognitive measure of crossmodal visuo-tactile interactions in peripersonal space. [1]

Wrong. They hypothesized that amputee participants would benefit, which as I may add would have been the whole and only point of this study.

Unless they were about to equip folks with two arms with a third or fourth arm, this study is pointless without amputees.

As I was there, I can say what I have to say (above). Besides, I am limbed. I may not be extensively limbed, but I am limbed. At times partly artificially, partly naturally.

Ever figured that any training with generic stuff, like, game controllers, has some crossmodal thing going? [3] I mean, you can also get there with an extensive prosthetic hand apparatus. But you could have achieved proof of principle regarding cross modal enjoyment, as such, probably by using a few participants even of unchecked "health status" provided at least one hand or so, rubber gloves, a toilet and a few typical glossy center fold type magazines [4].

The present results hold potentially relevant implications for amputee patients. The need for a sensory feeding-back prosthesis has been recently emphasized and its development is considered an impending need by experts across multiple disciplines (Micera, 2013). [1]

You can get there with different prosthetic arms as well. It does not have to be the buzzing electric extra painful sensory feedback variant.

I had already offered during the tests, to also run the test with my Becker hand.

The researcher rather violently rejected my idea. I guess your research premises are holy, and they must not be touched. I guess you are afraid what comes out when one generalizes from this.

"The need" however, is not that.

Were you to write up your premises better, then you would know that the need is to build useful prosthetic arms.

As I tell everyone: start with the suspension, then work your way towards repetitive hard strenuous bimanual tasks first.

And don't complain to me, if you do not read or listen.

Missing from this study: ill effects, drop outs, complications.

So as it appears, this study totally omits me. That is fine in principle, but would they not have to declare this? Why not be honest.

Corrected text

The study I am sure has its merits. So instead of discarding it, let us "correct"it. Here is how they should have written this:

Introduction. Amputees want weird prosthetic arms - like, light weight, robust and comfortable, affordable and cool. Amputees also look funny and so they seem crazy. That is why researchers have separated themselves from amputees since many decades. We researchers therefore do research on something that we find interesting to play with. For that purpose, we have a funny moving hand that is real heavy and that sometimes even manages a grasp or two. And we have buzz electro shockers we can use to startle people. We figured we would use that to write a paper. Materials. A few of us got together to be the "study collective". And we were surprised to see that an amputee would join us too. Results. We found that extensive playing with the prosthetic arm stuff would cause some fMRI signals. The amputee cooperated, but he had lots of pain and crapped out, but then, hey. He complained that our sacred toy was not working, and mentioned his hook prosthesis and Becker hand. Discussion. Playing extensively with anything will generate fMRI signals in the brain. Including game controllers or having sex. Even doing an fMRI of a dead fish will produce a result. So that is that. The amputee really did not hold up, but then, no one really understands these people. He even mentioned his hook and his Becker hand during the research, which confirms that he really must be weird. Wearing these is not "healthy" for sure because how can he have sensory feedback. In the future, let us do more research with "healthy" students. All other things aside, it was great fun!

And with that (poof) the satire detector machine exploded with big puff.


Paper as PDF here 1-s2.0-S0028393213004144-main

[1] [doi] F. Marini, C. F. Tagliabue, A. V. Sposito, A. Hernandez-Arieta, P. Brugger, N. Estévez, and A. Maravita, "Crossmodal representation of a functional robotic hand arises after extensive training in healthy participants ," Neuropsychologia , vol. 53, pp. 178-186, 2014.
title = "Crossmodal representation of a functional robotic hand arises after extensive training in healthy participants ",
journal = "Neuropsychologia ",
volume = "53",
number = "0",
pages = "178 - 186",
year = "2014",
note = "",
issn = "0028-3932",
doi = "10.1016/j.neuropsychologia.2013.11.017",
url = "http://www.sciencedirect.com/science/article/pii/S0028393213004144",
author = "Francesco Marini and Chiara F. Tagliabue and Ambra V. Sposito and Alejandro Hernandez-Arieta and Peter Brugger and Natalia Estévez and Angelo Maravita",
keywords = "Crossmodal interactions",
keywords = "Visuo-tactile interference",
keywords = "Peripersonal space",
keywords = "Prosthesis",
keywords = "Visuomotor control",
keywords = "Plasticity ",
abstract = "Abstract The way in which humans represent their own bodies is critical in guiding their interactions with the environment. To achieve successful body–space interactions, the body representation is strictly connected with that of the space immediately surrounding it through efficient visuo-tactile crossmodal integration. Such a body–space integrated representation is not fixed, but can be dynamically modulated by the use of external tools. Our study aims to explore the effect of using a complex tool, namely a functional prosthesis, on crossmodal visuo-tactile spatial interactions in healthy participants. By using the crossmodal visuo-tactile congruency paradigm, we found that prolonged training with a mechanical hand capable of distal hand movements and providing sensory feedback induces a pattern of interference, which is not observed after a brief training, between visual stimuli close to the prosthesis and touches on the body. These results suggest that after extensive, but not short, training the functional prosthesis acquires a visuo-tactile crossmodal representation akin to real limbs. This finding adds to previous evidence for the embodiment of functional prostheses in amputees, and shows that their use may also improve the crossmodal combination of somatosensory feedback delivered by the prosthesis with visual stimuli in the space around it, thus effectively augmenting the patients' visuomotor abilities. "
[2] [doi] M. Rohde, M. Di Luca, and M. O. Ernst, "The Rubber Hand Illusion: Feeling of Ownership and Proprioceptive Drift Do Not Go Hand in Hand," PLoS ONE, vol. 6, iss. 6, p. e21659, 2011.
author = {Rohde, Marieke AND Di Luca, Massimiliano AND Ernst, Marc O.},
journal = {PLoS ONE},
publisher = {Public Library of Science},
title = {The Rubber Hand Illusion: Feeling of Ownership and Proprioceptive Drift Do Not Go Hand in Hand},
year = {2011},
month = {06},
volume = {6},
url = {http://dx.doi.org/10.1371%2Fjournal.pone.0021659},
pages = {e21659},
abstract = {

In the Rubber Hand Illusion, the feeling of ownership of a rubber hand displaced from a participant's real occluded hand is evoked by synchronously stroking both hands with paintbrushes. A change of perceived finger location towards the rubber hand (proprioceptive drift) has been reported to correlate with this illusion. To measure the time course of proprioceptive drift during the Rubber Hand Illusion, we regularly interrupted stroking (performed by robot arms) to measure perceived finger location. Measurements were made by projecting a probe dot into the field of view (using a semi-transparent mirror) and asking participants if the dot is to the left or to the right of their invisible hand (Experiment 1) or to adjust the position of the dot to that of their invisible hand (Experiment 2). We varied both the measurement frequency (every 10 s, 40 s, 120 s) and the mode of stroking (synchronous, asynchronous, just vision). Surprisingly, with frequent measurements, proprioceptive drift occurs not only in the synchronous stroking condition but also in the two control conditions (asynchronous stroking, just vision). Proprioceptive drift in the synchronous stroking condition is never higher than in the just vision condition. Only continuous exposure to asynchronous stroking prevents proprioceptive drift and thus replicates the differences in drift reported in the literature. By contrast, complementary subjective ratings (questionnaire) show that the feeling of ownership requires synchronous stroking and is not present in the asynchronous stroking condition. Thus, subjective ratings and drift are dissociated. We conclude that different mechanisms of multisensory integration are responsible for proprioceptive drift and the feeling of ownership. Proprioceptive drift relies on visuoproprioceptive integration alone, a process that is inhibited by asynchronous stroking, the most common control condition in Rubber Hand Illusion experiments. This dissociation implies that conclusions about feelings of ownership cannot be drawn from measuring proprioceptive drift alone.

}, number = {6}, doi = {10.1371/journal.pone.0021659} }
[3] A. Lécuyer, "Simulating haptic feedback using vision: A survey of research and applications of pseudo-haptic feedback," Presence: Teleoperators and Virtual Environments, vol. 18, iss. 1, pp. 39-53, 2009.
title={Simulating haptic feedback using vision: A survey of research and applications of pseudo-haptic feedback},
author={L{\'e}cuyer, Anatole},
journal={Presence: Teleoperators and Virtual Environments},
publisher={MIT Press}
[4] B. A. Arnow, J. E. Desmond, L. L. Banner, G. H. Glover, A. Solomon, M. L. Polan, T. F. Lue, and S. W. Atlas, "Brain activation and sexual arousal in healthy, heterosexual males," Brain, vol. 125, iss. 5, pp. 1014-1023, 2002.
  title={Brain activation and sexual arousal in healthy, heterosexual males},
  author={Arnow, Bruce A and Desmond, John E and Banner, Linda L and Glover, Gary H and Solomon, Ari and Polan, Mary Lake and Lue, Tom F and Atlas, Scott W},
  publisher={Oxford Univ Press}



Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Feeling with a prosthetic “bionic” hand [research review] II; published 26/08/2014, 12:42; URL: https://www.swisswuff.ch/tech/?p=3350.

BibTeX: @MISC{schweitzer_wolf_1621245611, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Feeling with a prosthetic “bionic” hand [research review] II}}, month = {August},year = {2014}, url = {https://www.swisswuff.ch/tech/?p=3350}}