The SHAP Southampton Hand Assessment Procedure – as anyone might know – is an ill devised test for the purpose of prosthetic hand testing inasmuch as real prostheses used for actual jobs and tasks are concerned [link].
As we shall see right from the outset, a clear understanding of the problem at hand (what constitutes a useful test for bi manual activities?) is crucial. And I should know because of activities that leave any “extreme load” prosthesis far behind:
- IKEA Pax system (total of over 540 kg materials installed in 2 days) [link] (measurable activity with standard object and defined goal)
- Trimming hedges in direct sun and summer heat at over 37 degrees C [link] (clear task definition, precisely definable tools and physical environment)
- Biking up the Stelvio Pass (highest paved alpine passroad, over 2700 meters above sea level) [link] (very standardized task, suitable for competitive bike races as well)
- ah, search this site yourself, will you; there is a sitemap [link] or at least read through all the way to the bottom here
The Cybathlon 2016 [link] currently is aimed towards using the SHAP with the goal to push the development of “bionic” lookalike prostheses, that is, to push development not of actually functional prostheses per se, but to promote the overpriced gadget track that so many manufacturers have fallen for recently. A more detailed review can be found here (in German) and here.
Initially, they wrote: “B. SHAP Course ADL — This course is based on the Southampton Hand Assessment Procedure (SHAP), which incorporates different object shapes and sizes that require the use of different grips (spherical, tripod, power, lateral, tip, extension)” [link].
They amended this in the meantime, but that does not change the fact that the test goal for prosthetic arms is elsewhere altogether.
Thus, we read the very revealing ANSI note (link):
New York, May 16, 2014 – In most athletic competitions, using technology to give yourself a competitive edge over other athletes could get you disqualified. That’s not the case for participants in the Cybathlon, an international athletic event scheduled to be held in Switzerland in October 2016. The event – which will feature athletes with disabilities who make use of prosthetics, exoskeletons, and other assistive devices – will award medals to the winning athletes, known as “pilots,” and to the companies that developed the technologies they used. In the run-up to this unprecedented competition, standards can provide manufacturers and others with useful guidance regarding the safety and effectiveness of the devices used by the event’s athletes. The Cybathlon will feature six different events involving a wide range of technologies and athletic disciplines, including a foot race featuring pilots with leg prostheses. An International Standard developed by the International Organization for Standardization (ISO) can provide prosthetics manufacturers and others with important guidance. ISO 10328:2006, Prosthetics – Structural testing of lower-limb prostheses – Requirements and test methods, includes strength tests for lower-limb prostheses, including above-knee and below-knee devices. The standard was developed by ISO Technical Committee (TC) 168, Prosthetics and orthotics; ASTM International, an American National Standards Institute (ANSI) member and audited designator, serves as the ANSI-accredited U.S. Technical Advisory Group (TAG) administrator to ISO TC 168. The Cybathlon’s planned bicycle race will feature athletes with spinal cord injuries using Functional Electrical Stimulation (FES) to pilot their vehicles around the race track. ASTM F2711-08(2012), Standard Test Methods for Bicycle Frames, could provide important support for the manufacturers of the FES bicycles needed for the event. The standard, developed by ASTM International, establishes procedures for testing the structural performance properties of bicycle frames. Another planned event will require participants to maneuver powered wheelchairs backwards and forwards through an obstacle course. The Rehabilitation Engineering and Assistive Technology Society of North America (RESNA), an ANSI member and accredited standards developer, has developed an American National Standard that provides important guidance related to the seats used in wheelchairs. ANSI/RESNA WC-3:2013, RESNA American National Standard for Wheelchairs – Volume 3: Wheelchair Seating, is focused on postural support and tissue integrity management assistance for wheelchair users. Perhaps the most unusual event planned for the Cybathlon is the brain-computer interface race, where paralyzed pilots will control vehicles in a computer game with their mind. One promising method of mind-to-computer communication uses electroencephalographs to record electrical brain activity, providing a basis for mind-driven control of computers and other machines. IEC 60601-2-26 Ed. 3.0 b:2012, Medical electrical equipment – Part 2-26: Particular requirements for the basic safety and essential performance of electroencephalographs, provides safety and performance requirements for electroencephalographs in the clinical environment. This standard was developed by International Electrotechnical Commission (IEC) TC 62, Electrical equipment in medical practice, Subcommittee (SC) 62D, Electromedical equipment. The U.S. plays a strong leadership role in the work of TC 62, with Dr. Rodolfo Godinez of the United States serving as chair. ANSI member the Advanced Medical Technology Association (AdvaMed) serves as the United States National Committee (USNC)-approved TAG Administrator for IEC TC 62. The U.S. also holds the secretariat duties for SC 62D, which the USNC has delegated to the Association for the Advancement of Medical Instrumentation (AAMI), an ANSI member and accredited standards developer; AAMI also serves as the USNC-approved U.S. TAG Administrator to SC 62D. This exciting event promises to give athletes with disabilities an important new opportunity to showcase their skills while also encouraging the creation and refinement of technologies beneficial to many other persons with disabilities. And when developing the devices that will assist Cybathlon pilots in their athletic feats, participating companies will have an array of helpful standards to draw from. To learn more about the Cybathlon, visit its official site.
Interestingly, the ANSI author does not mention the prosthetic arm / hand race with one single word. Not one word! This in plain American English is as clear a statement as there can be a statement. However, this blog-website here is more verbally explicit.
Instead of just keeping my mouth shut, though, I will critique the attempt of using the SHAP or such, the publicizing, the maneuver so to speak, as there are rather constructive insights to be gained by doing so [link].
Much rather, the SHAP has been conceived with totally different goals in mind. It really serves the performance tracking of a two handed individual’s recovery from surgery, illness or trauma over time. That is where the SHAP has its actual role. Its tasks were not validated, tested and approved for any purpose of prosthetic hand testing. To no surprise, using it on prosthetic hands already was really demonstrated to yield strange results that no one really could interpret.
The current motivation for illustrating these tasks under the amputation assumption as test parameter is not that they are so totally good or great tasks. They are not all bad as tasks generally – but they just do not test so much as they fail being a reliable test for prostheses. The current motivation is to comment on what they do NOT test. And what else there is to say about these tasks. And to arrive at a more differentiated view of what could be a good test for prosthetic hands or devices.
While all of that is so very obviously and totally non-sensical, it still warrants a more detailed look at their targeted test procedure, because many people show how they have so comprehensively no idea about the subject altogether. They are not even far from it. They are eons away.
And to make some of that visible and give us something to talk about, I will go through a number of these tasks using three methods:
- an iLimb Ultra Revolution (wearing a work glove) – cost: 80’000 CHF
- a Becker Imperial hand (wearing a very similar work glove) – cost: socket / body powered arm setup 7000 CHF; Becker Imperial hand 650 CHF.
- no prosthesis at all – (obviously at no apparent extra cost – but the hidden cost are a mild increase in skin and tissue damage, in my instance at an estimated average 100-200 CHF a year including but not restricted to mechanical injuries, frost bite and burns).
The instructions for the SHAP explicitly state for amputees to adapt tasks to their preferred way of doing things. That is exactly what I did. There is no point fidgeting around when all one has to do is getting the job done.
So, here we go.
1. Spherical object: apple
Lifting apples around is not a relevant activity for a prosthesis.
You could, obviously, but why would you (remember the title and name of this blog? did you navigate here on your own account? there, then). Lifting very ripe mangoes around is even less such a task but even more of an issue, and if you are a mango fan I would question your sanity were you to lift around totally ripe soft fruits with a prosthetic hand or hook. You really do not want to lift these around too much, it at all, if ever use a thin soft bag or so. But eat these fruita! Do that, and get it over and done with.
S0 if necessary, I will use my (left) hand to do it. But it can be done without a hand or with a prosthetic.
Just to show this here: rating this activity by speed or by completion will not achieve or test a thing.
What may be of interest is how well the apple fares. Or standardized ripe mangoes. Document their damage.
The iLimb has problems because it switches grips on its own, too. Also, the socket is not reliable in terms of fit (I did not build it, so don’t blame me), so I have to push the socket back into position. That is a problem that many myoelectric arms have. If you do not account for it you may miss out on a relevant issue.
The Becker hand is finely graded in power and grip delivery so no problems. Also it is fast [link]. The socket and liner are flawless. Also it is a lot faster than any myoelectric prosthesis. And it costs only a tiny percentage. In short, it is a lot better. But we knew that! Damn guys, why do you make everyone repeat this all the time. Order a Becker hand for yourself before you type up your next research application.
Grabbing stuff is such a no brainer.
Just for shits and giggles I also performed it with no prosthetic arm on. Now you will shut up about this. Will you?
What really should be tested
Speed is not interesting here. Why would you derive meaning from measuring it.
What is useful to move spherical objects is either a suitably shaped gripper (like, most hooks) or an adaptive grip. That’s it. Not more is tested.
My Becker hand is very fast and precise. But what does it prove for developing electronic toys? Nothing does it prove. Besides, when I do it faster than Ms Miller or Mr. Smith, is it the prosthesis that is better? That what you believe? Where does speed matter when unpacking groceries – besides, what differences hold relevance here?
Also because body powered technology is way ahead here, you would want to chill a bit. I am telling you that, I am not asking. You will really want to chill here.
Damage control: More importantly, if you transfer or handle a pineapple, the brittle but ultra expensive original iLimb gloves will suffer penetrating damage. That is what prosthetic manufactures would really want to rate. My bet is that such perforation ratings for handling of fruits with spikes and sharp bits would definitely speed up prosthetic development in a sensible way.
Knife sharpening: Peeling and cutting onions. Cutting up tomatoes. Peeling and cutting up potatoes. Bimanually. I find one type of peeler to particularly well fit into my hook. But what does that prove. I also found that regardless of the question what or if wearing a prosthetic arm is the way to go when cutting up round stuff in the kitchen, it is the sharpness of the knife that really determines the fun that can be had. Extremely sharp knives and a cutting board with a peripheral groove are sufficient to cut up round items really well. So if you really want to know the truth about round fruits and vegetables – I do not obsess about the prosthetic arm, and I do not specifically put it on to cut stuff such as round items. What I do is regularly sharpen my knives.
Gloves: And if you lift around very soft round objects a lot, you may want to consider some other aspects of grippers. Then, maximizing grip contact area and maximizing friction – such as by using Wonder Grip coated gloves like me here – are the way to go really. Regardless of the type of hand you are wearing.
So the “grab round objects” test in prosthetic hand or hook life does not convey the same meaning. To me it spells out differently. Be careful with spikes, sharpen knives, wear gloves.
2. Coins
Shuffling coins around is not a frequent task for me. I usually pay with a card. So, that is that. Besides, handling coins with a glove equipped Becker hand may be hard to surpass.
The only thing really no one can do well is lifting off flat coins from wet smooth surfaces – with a hand, hook, prosthesis or otherwise. There, the vacuum bean bag gripper comes in [link]. Let me know if you are ready to consider living life as a competitive coin-picker-upper with a 300 watt bean bag vacuum sucker on your arm and a car battery on your belt. I will be interested in your experiences.
The iLimb can in fact be used to pick up a coin. But it does have a somewhat problematic precision grip, that hand [link].
Due to its finer control and far better precision grip [link], the Becker Imperial hand is just so much better at it.
But if push comes to shove and no prosthetic arm on, one still does not have to leave coins behind.
Sorry to disappoint the ones that thought, “oh, an arm amputee! he will surely leave coins behind because he does not HAVE THIS NEW PROSTHESIS on!”.
What really could be tested
If you test surface lift-off, the glove or hook surface characteristics will be the key to success here. With the same Wonder Grip glove that I use as you see in the videos, the iLimb and Becker hand have very similar grip characteristics all of a sudden. So if you want to test prosthetic hand and control design (which then would make sense really), best to use tests that do not heavily depend on the type of glove. Conversely, wanting to spend time with picking up lots and lots and lots of coins (rather than just one) using a hard metal hook or, worse, a hard metal hand, would be totally senseless. And before starting to compare decisive covers – rubber layers, glove coatings, and so on, why not revise testing of the prosthetic device to begin with?
You will lose on every account with your gadget hand if all you rate is “time” or “speed”. What really counts here is immediacy and coordination, as those are the interesting features of my body powered arm. As opposed to the outdated myoelectric stuff that takes ages to react. Really what you want is to build a myoelectric arm that is superbly fast and well coordinated in its motion. Once you built that, my guess is that we will find better ways to test that than picking up a coin.
Going for time here is no fun – my prosthetic hook and Becker hands are totally fast and precise, I do grade their power with massive precision nowadays. Also practice more than anything else is the key. Coins are impossible to pick up if they are stuck on a surface, so you depend on the surface’s edge. Really this tests the test setup and amount of practice with coordination more than it is any proof of grip technology at all.
- Handling scissors and tweezers is a far more relevant test if you look for testing on that order of magnitude in terms of motor and control precision.
- Also, handling contact lenses.
- Handling glasses, and cutting nails using clippers or scissors.
There we are talking relevance. However, developing prosthetic hands that handle scissors really well has not been attempted yet. Manipulating tweezers is actually quite easy if you have the right type of hook and tweezer that match, size wise and notch wise.
So, that is that.
3. Jar lid
Holding on to a jar to open or close its lid is certainly an honorable way to see whether you will make it through another day without starving too much. probably.
The iLimb:
The Becker hand:
No prosthetic arm on:
Based on how large or small the jar is, and how hard it is to open the lid, this test is absolutely impossible to complete, or, it is feasible, if not totally easy.
So it is not a stable test that is set up and then all requirements are equal.
Much rather, the details of the test setup are the main determinant of how the results look like in the end. This does not make it a useful test for fair or even overly relevant prosthetic device testing.
What really is interesting
Jar lids that have a massive vacuum are a real challenge and of true interest to everyone in the community. Personally I use a drill to relieve the vacuum [link]. Also I bought a simple saw blade mount that helps even with the strongest vacuums [link].
Now, the types of jars I encounter are these:
- Marmelade jar. These are, nowadays and with aging customers, also sold to the over 80 year old people. To keep customers happy, these jars have a special type of vacuum that is so easy to open I can almost do it single handedly. No kidding. So do not use these for testing grip strength. These are now engineered to work with weak grips! Do not make this an engineering duel.
- Cucumber jar. These are attractive to buy when they are totally large. Vinegar cucumbers are great if you can buy the large glass jars that are so perfectly sealed they remain good for 2-3 years. These are vacuums that deserve the name. Probably not a single oxygen molecule left in there. Only: no one can open these. These jars are not meant to be opened. Their prime destiny is to stay closed, possibly even at earth quakes over 12 on the Richter scale. If you want to even attempt a weak argument towards the position that “an iLimb should be able to…”, you will be facing consequences of a sacrilege. Because iLimbs are built for nutty surprises including weak grips, and these cucumbar jars are sealed for eternity.
- All in between are unstable in terms of their determination – do I want to be a jar that opens itself easily, or do I keep my secrets forever. In between, prosthetic hand testers will find only despair and failure.
You could, instead of time testing an unstable criterium such as the vacuum of food jars (see above), just measure the sizes of jars that can be held and the amount of force the amputee can apply. Then you can use these results for ranking the person or “pilot”. Then, sell them anti slip gloves.
Just, what would that prove?
You really want to test other food containers:
- Rip open a small paper bag with baking powder that is covered with flour, dry and slippery. Then, who first spits in his hands to improve grip wins this one.
- Open an aluminum foil wrapped chunk of butter and remove the butter. Whoa, too thin, too oily.
- Hold and use a clogged pepper mill that is milled to be rotationally symmetric and made from totally smooth wood or such. That is a super realistic test. Most prosthetic hands and hooks actually fail that test. If you manage to show up with a Super Wonder Grip glove on your prosthetic hand, your race is halfways won.
4. Power grip – banana
The power grip is demonstrated here by holding, also peeling and eating a banana.
Grabbing a banana with an iLimb: yes, that works.
But really who would buy that expensive bird for just grabbing a banana. Here is the Becker hand with the banana, it’s just so much better – finely graded, fast and smooth:
How to not just hold but start peeling the banana without a prosthetic arm on:
What we really want to test
Power grip used on a banana is performed with all excellence using body powered arms.
Do not go for time or speed here unless you are prepared to really lose. Besides, no one wears a prosthetic arm just to eat a banana – but let that remain a secret of just the two of us here, me the author and you the reader. Do not tell it to other people.
Really, the power grip has so much more to offer.
Of course, lifting a 20 kg trash bin by its wheel axle really puts the power grip to a type of use that warrants the use of the “power” word part. Also, using a vacuum cleaner or cleaning the street using a broom with a long handle, or maybe rolling down a sun awning with a manual crank can visualize the usefulness of a technique or maybe even prosthetic. Whatever happened to using a power grip to mow a lawn? With a mechanical manually driven lawn mower? The type that gives you blisters on your “human” hand after 10-15 minutes? Did you believe that you could just crawl away from the more painful sort of power grip this world inflicts unto us every day everywhere all the time?
And our troubles only start there. Really testing a power grip will also really test the control paradigm: will the device stay closed despite full lift force required? Will the device parts withstand the heavy weight? Will the socket contact to the stump stand trial here? What about the farmer that posted to user forums he’d lift his plough to connect it to his tractor, all 50 kg or more of it? Would you want to build a prosthetic arm for such tasks or would you rather not, and, why is that.
People that cannot build sockets should not build prostheses at all, let that be said in all clarity here. People that have no idea that “power” grip also and consequentially spells out “power” wrist connector, “power” socket, “power” pin lock, “power” liner to stump contact, “power” upper extremity, and quite possibly, “power” amputee, really have no business using the word power in conjunction with grip at all, let there be no doubt either. I want to see power, I want to see repetitions of it, hard series that make the candidate fall apart maybe, and then I want a full part and skin inspection and if there is as much as a single friction blister or lose screw, the responsible prosthetist will show us 200 pushups also right then and there.
5. Tripod grip – lamp object
Lifting that small rod shaped lamp shows how relevant or irrelevant the distinction between grip shapes is for actual prosthetic every day work – getting stuff done.
The ever so ill devised control paradigm for myoelectric prostheses shows itself here: you cannot really lift the forearm over the elbow without co-activating muscles that also trigger the electrodes [link].
Trying to grab the object with the iLimp:
Now really performing fast and precise object handling with the Becker hand (did I mention that worked a lot better):
But before I have to leave it behind I can always just squeeze it into the elbow crease.
What we really want to test
Testing a fast repetition trying to put 80 or 200 of these plastic lamp objects reliably from a table into a box should be interesting.
Seeing how many fall down when having the person walk 3 meters for transferring these without any allowance for trays or containers.
That however might – on average – illustrate how ill devised myoelectric arms can be for below elbow amputees.
6. Jug handling
The SHAP has this jug handling test. One will have to pour water into a glass or so.
Really, I want to show here that using the right type of jug, anyone can do it. Using the wrong type of jug, it is practically impossible to get a firm grip.
So in true fact, the jar handling test of the SHAP for prosthetic hands or devices only tests how good the purchase of the jug was. In relation to the prosthetic device one wants to use.
If I use that carafe, I can pour glasses with the Becker hand all day long. The hook works very well too. Do not try a myoelectric, you might trigger something and the jug falls down making a big mess.
The iLimb may not be your first choice here:
The Becker hand would, in fact, be the prosthetic option you really wanted. I am telling you.
And carrying a jug works without a prosthetic on, one does not have to walk one extra time for just a jug:
This test is unstable setup-wise, because the choice of jug determines what type of prosthesis will succeed. So really this is not a test that can ever be applied fairly. I know why my jugs work for me, but do they work for you – that is the question.
What we really want to test
This is where I want engineers and roboticists to prove the trust they have in their myoelectric control by placing a delicate personal item underneath any jug that is being handled.
Such as their cell phone or laptop computer.
Because really, a person that does jug handling to rely on it, will want to refer to body powered technology or use the stump because as strange as that type of grip then is, it is totally reliable. See below for rating of “ease” and “reliability” other than “speed”: quality of life first and foremost means to not dropping liters of juice, tea or other drinks all the time. So we really want to know what you would use, were you to really rely on the grip here. Like me.
What if you were to pay a 10’000 CHF fine if you dropped the jug once? Would you still use an iLimb? Would you find myoelectric control super cool then? And I would increase the amount just until I would see the white in your eyes there.
Task for you guys: given very limited budget, build the prosthetic arm – including all parts! – that really reliably grips this, and that does not drop it. That should be tested. Even at the expense of postural twists, relatively rare daily occurrences like me pouring water from a jug do not cause me any back problems. So I might well just use the stump, or twist around, or whatever. Other situations have me worry more: unlike pouring water from a jug, highly repetitive activities put a strain on my back. Like, typing, scrubbing, carrying items when cleaning out. Heavy and really heavy objects also put a strain there. Not a bit of a jug. Now go learn the difference between occasional weird stuff and actual overuse risk, you perpetual jug pourers, you!
7. Cut and eat food – fork and knife
What is tricky, what is not tricky, *that* question is tricky.
Eating with knife and fork with a right below elbow amputation (and you thought I forgot to remind you just on what blog you are here?) is considered tricky but it is not. While it is totally difficult if not impossible to get the point across that electronic and myoelectric arms are not so useful as it appears, eating with knife and fork is a total no brainer, no matter what equipment or not. So here is that riddle for you.
The iLimb may be used to eat with knife and fork:
It is however not the first choice. Hosmer hooks or Becker hands are better, because they are far more robust, the grip is more reliable and the devices are lighter and FAR more affordable:
And eating out, also with knife and fork, does not at all require a prosthetic hand or hook. It can be done “as is”.
I do not even see this as a test. What do you want to test here!
What we really want to test – table manner techniques!
We really want this one thing: what all in terms of table manner techniques can be successfully mastered without any prosthetic arm or hand? Can there be a trick and technique collection that tells us all the ins and outs of garden parties, receptions, small bits, luncheons, how to handle tiny plates AND a drink when missing a hand, how to butter soft toast bread with fresh frozen hard butter. That is really what everyone is after.
Because, see, your “bionic” “robot” hands just drops 1 bit once in 2 months in the wrong time and wrong place – and you will not sell it to many people any more. Dropping stuff just is the ultimate No Go. You learn to get stared at for looking amputated, but you will not learn to get stared at for continuously dropping stuff.
So, really, either your prosthetic totally performs. Or we will all be interested in how it’s really done. Either you build technology for real life.
Or you don’t.
Chances are you don’t.
And it’s not that we don’t know.
8. Zipper – demonstrating on a jacket
Closing zippers on jackets always is the thing. One stabilizes the jacket with the prosthetic device or with the stump, and one handles the zipper with the other hand. Anyone doing it differently probably (sorry for the euphemism, I meant to say “surely”!) does something wrong.
The iLimb is as good as any stick or stub to stabilize a jacket for zipping it up.
The reliability of the Becker hand’s precision grip [link] is totally better than the reliability of the precision grip of the iLimb however [link]. Check this out. You do not want to get into taking a time here.
In fact, I never froze up even without prosthetic arm on. How could that be. Here is how.
The test is unstable and therefore useless – because, there are smaller and larger zippers. Larger zippers that run easily and do not jam: anyone can use these, with probably any type of terminal device.
Small zippers, that jam easily or that block, those are the real challenge. But why test prosthetic devices on hard to use zippers? What does that show? Ultimately, you pick the zipper and we know whether hooks or also hands can complete that task.
What we really want to know
Time is not of essence when closing a zipper. You can test that if you must. Because directly depending on the type of zipper, you fail, struggle or perform. That then would again say more about you than you may actually want to give away. Because let me tell you that I have some zippers here that no one can successfully close or open. If it is not necessary best to leave them untouched. Other zippers are totally awkward to reach with a prosthetic hand or hook. Can you tell me which you believe these are? Why only a super strong super precise pincer grip will have a chance at succeeding and why applying that – in, say, a public toilet – could be wrong for a range of reasons? Could you name a few?
Remember the Real Programmers? Real Programmers Don’t Eat Quiche [link]? So, there are people such as researchers that believe in using zippers as a “valid” “test” for a “prosthetic device”. Quiche eaters. And then there are Real Men, that regularly maintain their zippers by putting a bit of silicone spray or oil on them. A big cheers on everyone of us who does that. Keeps the SHAP speed clockers out of the house!
So if you really need your pants go work totally easily with typical jeans metal zippers, attach a small leash on the zipper. Then you will find it opens and closes easily. But it looks really weird. Then, the prosthetic device will become a lesser social problem and other issues may attract stares instead.
It was not my idea to discuss zippers and prosthetic hands. It is included in the SHAP for some reason.
Um, really, you should probably now start to worry about stuff that matters and that can still be tested with at least some decency. What really is a cumbersome task for a prosthetic hand, in conjunction with a jacket or coat, is getting through the sleeves! Wearing work gloves or with a hook that is not an issue. But with silicone “life like” appearances this is a major problem. Drop me a mail once you solved that. That is what the research of yours could address. But it was not that you cared that much, did I get that correctly ; )
So, zipper test, unstable as construct, and sense free to use for speed or time testing. What matters is whether the amputee can close the zipper at all, and in a way that does not damage the zipper. That will greatly depend on the type and state of the zipper.
9. Buttons – demonstrating on a jacket
Here I show how buttons are closed. For shirts, I hardly ever open or close buttons as I put on or take of shirts similarly to taking off or putting on t-shirts. I mean where are we.
iLimb…:
The incredible Becker hand doing the same:
Buttoning up jacket without prosthetic arm on. Works just as well.
Close-up and in slow motion, button closing requires a very hard very precise pincer grip by the prosthetic device. The smaller the button the more extreme that requirement. By button and button hole selection you will pre-determine the terminal device that wins this race. Very small buttons – no one wins. Relatively small buttons – hooks win. Larger buttons, increasingly weak grippers also can win. So really this is an unstable test method for the purpose of prosthetic device testing.
What we want to see for buttons – tiny top button of narrow collar dress shirt
For a business male person, there is only 1 button type in life that really counts: before doing an actual test race, I want to see a prosthetic hand developed that can manipulate these tiny top buttons of dress shirts.
And before anyone has actually performed specific steps towards these meanest buttons of them all, no need to include these in the Cybathlon.
It may also be easier to just expand the dress code requirements for arm amputees than to solve the top button issue mechanically. In fact, it is my experience that not closing the top button of a dress shirt when wearing or not wearing a tie in tight dress situations has caused me problems of any kind so far in zero out of dozens of times.
So, thank you for worrying about the top buttons of dress shirts with me.
Don’t.
10. Flip pages – reading a book
Just lick the finger and push the page over. Why would that be any different for me?
Using iLimb to flip book pages:
Becker hand, no worries:
Reading book without prosthetic arm on (and I had you really worried that without advanced robotic hand I could not flip through book pages and with that I would remain uneducated and stupid? no, rest assured, all is safe):
What we really want to see
A prosthetic hand with a built-in camera that does page deformation real time tracking, that does five finger adaptive minimal touch but not tear action at blazing speeds, yeah, that would be a real looker.
But honestly, page flipping being difficult or a challenge never crossed my mind so far. Sorry.
11. Tray
The real issue when carrying a tray is not letting go. If you want to be totally sure, you will either go underneath – what I do with the stump or myoelectric arm due to its ill devised control paradigm. Body powered arms can be relied upon, as you can see totally no problem there.
The iLimb actually manages to stabilize a tray:
It is just that, again, the Becker hand is so much better at it, both in terms of precision grip / power grip, and in terms of reliability:
But I carry food trays, such as the ones in the Mensa, without any prosthetic on.
What you could test also
You should consider testing heavy tray carrying.
And maybe, you could get something out of making it a balancing test when piling up a few tennis balls or so to see how wiggles the tray and who does not. Ah, I don’t know.
Myoelectric arms can be such a bitch, can they ; )
Discarded tests that the SHAP lists
1. Screwdriver and screw
The SHAP provides for a screw driver test.
Now come on boys. You want to seriously promote ridiculously technologized hyped useless uber gadget prostheses and don’t even have the brains to include cordless screwdrivers (Akkuschrauber) in your budget? Worse, you consider an amputee that will go through the hoops and hollers to finance an 80K USD device, to not even think about tools everyone and their grandmother are using these days? How ridiculous is that.
Maybe your paradigm is off though. So you still assemble your Ikea stuff using manual screw drivers? Then why are you opposed to body powered prostheses? I mean honestly. Do not make me illuminate your thinking gaps with too much light here.
No, guys. Everyone and their grandmother knows that for real screw, nail, wire and tool handling, normal people wear body powered arms and high power high precision devices. Such as the Retro by Toughware PRX [link]. And I use modern tools. I also have grinders, a drill hammer and other things people have. With me: “amputees are people JUST like everyone else, just that they are amputees”. They do not lack the general ability to think or buy tools. So, please.
Here is how it is done, really [link]. Start from there with your “testing” if at all you must. A real timber type competition with drill hammer concrete hole drilling, gardening and stuff – that would make for a great day out with the prosthetic arm.
2. Door handle
Because I do not have round knob type weird door handles, I did not do videos on door handles. My door handles here are normal push down handles. They work well without any prosthesis, so nothing to test really.
Qualitative SHAP results
This diagram gives an overview over what there is to be said regarding the SHAP and prosthetic hand use. Prosthetic arm price estimates new with socket/suspension.
Firstly, the diagram shows us that speed is only one of the many aspects that matter. Body powered prostheses and the bare stump win in terms of speed, hand(s) down. And that is hardly new.
Even though, speed in conjunction with manual disability is something of a fetish because there is no daily correlate. There are situations when people stare and pressurize, even verbally direct, that I should hurry, such as when standing in line and packing stuff as in a book or grocery store. But such aggression is not effectively treated by being faster, ever. It is effectively treated by realizing what this is – a person with no apparent disability taking it upon themselves to make a person with handicap feel bad for sheer lack of respect. And by far the most effective treatment is to return the favor. So instead of making things faster, turn full frontal, and take things from there. What really matters when packing groceris is getting all items home without damaging any. Not how fast they were packed.
And so, speed of ADL are the only aspects the SHAP actually quantifies and tests. What a waste of time! Since when are we in kindergarten and everyone screams, hurry up, tie your shoes? The modern researchers’ arena aims to push myoelectric “bionic” hands – not Becker hands, which are just better overall and in any respect from view of a user.
So they really have to think something new up.
We may need a new paradigm under which “bionic” hands win, but functionality in a manual or bimanual sense, or a user view on ADL, that is not the path out of the mud.
So what else is there to be said?
Ease. The ease, elegance, postural accessibility of a grip or activity, that can become a very important aspect. If you do something over and over, that “ease” is what you feel by the end of the day [EODF end of day feeling link]. If you need a list of activities that are relevant for testing “ease”, then typing, vacuuming, cleaning dishes, ironing, and such come to mind. As you can see here, an iLimb and a bare stump both are relatively awkward to use across all SHAP tests – with the big difference that the comfort of a “bionic” arm [see stump damage after a few hours link] is a lot lower, while its price is certainly beyond any discussion. Really, if you need ease and postural support, body powered arms that are built right and correctly set up definitely are the way to go.
Reliability. If you attend a party, you have two options. Wear the weird bird or not wear the weird bird. Wearing the weird bird – such as the iLimb – will certainly generate attention and gadget lovers will love it. But really, it does not do too much. Due to inherent constraints, a “bionic” prosthesis will not be what you wish to rely upon to keep your host’s glasses un-smashed, your host’s carpet clean, your host’s plates unbroken [link]. You will find ways to deal with not looking just as pretty and either go with the body powered arm wearing Becker hand or a hook, or, not wearing any prosthetic arm at all. Best in terms of real reliability, your stump will serve you well to keep the situation under control.
What do we learn.
Strategically speaking, the SHAP – if done right – shows us first and before anything else, that the stump is the fastest and most reliable, the cheapest and most comfortable way of living. All that is really needed are knowledge and training for tricks and technique, workarounds and helpful products. Did you know that I legally drive my car without any modification and without prosthesis. Yes, that took some practice. Now, people will tell you that mastering a “bionic” hand will take months to years! With that amount of exercise, I can also work towards mastering the same activities without prosthetic arm and while the effort may be almost similar in extent and time, the effect is totally different – then I am far more self sufficient, empowered, rehabilitated and ready to face challenges.
We learn that if ease is a real factor for bimanual tasks, Becker hands (and by proxy, hooks) are the way to go. Hardly anything new though.
Thirdly the diagram exemplifies that to justify wearing an iLimb Ultra Revolution, none of the conventional ways to rate a particular way to go about ADL help explaining it. That does not make it an impossible or offensive product yet – it just shows us the limits of how we currently think. New ways of thinking are needed to explain what these gadget arms really do to us – but it is not speed, definitely not reliability, and certainly not ease of use, most definitely it is not appearance, really it is not the noise, with total certainty it is not comfort and in absolutely no way is it the price, that explains to us the “bionic” prostheses that we are currently witnessing as a phenomenon more than as a solution. But, about that, more later and elsewhere. Because after Sherlock Holmes, we know that if all rational and logical explanations fail us, logically and rationally, we are left with irrational answers.
Conclusion and advice
The Cybathlon is a revised version of the Paradrom Rathausen. You should now understand why it requires a weird mindset to exclude non-prosthetic-users from participating.
They do not seem to test actual bi-manual things that will totally fail without a prosthetic. They do not test these. I suggest mounting a ceiling fan. Actually, I already listed a whole number of things here. Maybe you can read up on it some day.
What to know and respect before going about prosthetic hands, arms and tests
Prosthetic arms are mostly never worn for fun. Except a very few geeks, most people have hard reasons for wearing their arms. IV – Swiss disability insurance – pays our prostheses for specific and very individual tasks. No two people and so no two arms are alike. Logically, there is no way you can do a grand overall test to capture sensible performances as all performances differ. Respect that, and you have done a lot for yourself.
Overuse is the single most important subject for the majority of us that actually do kick ass with the prosthetic arm. And that do suffer chronic injuries and overuse problems. There really are well thought out, well planned and extremely well justified reasons for designing and building prosthetic arms the way they are built [link].
The real test is time.
Tests that do kick ass
I assembled a range of activity reports under the keyword of “bimanual benchmark test” [link]. If you want to define useful tests, here is what to do [link].
Being mobile despite handicap matters.
- Driving an unmodified car is a real tangible issue for arm amputees [link][link]
- Riding a bicycle [link] – however, a bike mechanic once told me that you can ride bikes one handed without need for prosthetic add-ons. A few days ago, I tried that. True, entirely true. Once you have sufficient body core control, you can do very well with just one hand on the bike.
Self sufficient tinkering massively counts in life, so these activities matter. Many of them are uniquely bi-manual.
- How to mount a fan [link]
- Mounting wall lamp [link]
- Move stuff at home [link]
- Fixing a bag using thread and needle [link] for sewing [link]
- Fixing or repairing a computer [link]
Hard dirtier work also should be relevant for many of us.
Kitchen work always is relevant so why not test something there.
The ultimate appearance test is explained here [link].
In the meantime, by August 2014
I was invited by OANDP-edge to contribute a commentary [link]: (PDF).
Text: Improving Prosthetic Arms through Better Testing – by Wolf Schweitzer, MD. Content provided by The O&P EDGE. For those of us who live with upper-limb loss, we wear prosthetic arms for specific reasons, if at all. Improving these devices requires adequate problem identification and, thus, testing. To do this effectively, we must define what, exactly, should be tested. One of the reasons people with upper-limb amputations wear prostheses is for appearance, an attempt to blend in. But my experience with the current bionic options has been that they are expensive and fail to achieve a “natural” appearance. Try to attend a meeting wearing one of these, and just by pouring yourself a glass of water it becomes apparent that you are wearing a prosthesis—the hand is too loud and artificial looking, and the posture too stiff. To overcome these downsides, we need shamelessly unforgiving appearance tests to expose these deficiencies during the development of prosthetic hands. Appearance aside, reliability/performance is the single-most relevant factor in prosthetic acceptance for many upper-limb prosthetic users. Shopping, ironing, handling containers, and preparing meals are examples of essential tasks the person will need to perform with the device. And given the somewhat reduced social acceptance that arm amputees seem to experience, attending parties or functions are of particular interest, and with those events comes the handling of delicate, breakable items, such as drinking glasses, or slippery objects, such as olives. The confidence that you will not drop or break anything outweighs any other aspect, even appearance. So even without wearing a prosthetic arm at all, I may perform with 100 percent reliability and therefore be more accepted socially than when wearing a high-tech arm. Prosthetic arms are also worn for functional tasks specific to work, home, garden, and recreation. These include manipulation of objects too heavy for single-handed work; repetitive activities, such as handling laundry; transfers or transports; or a combination of mechanical strains, such as weight and vibration; as well as handling tools, such as knives, pliers, or scissors. Every profession and job requires bimanual activities that may carry a risk of overuse, particularly when improperly balanced. So how can researchers ensure that the prosthetic hands and arms they design actually meet these needs? To test appearance, have someone perform a typical daily task in front of a panel of observers, such as pulling out a wallet, handling the wallet and money, then buying a cinema ticket. Ask the observers to note when they can confidently identify on which arm the prosthesis is worn. Test to see how bimanual job-specific tasks are supported, test for these specifically. For reliability/performance and functional testing, ask the user to perform activities he or she might encounter in daily living, such as cutting hedges, moving furniture or boxes, or serving soup. Count the number of items dropped. More practical testing should lead to more practical solutions. When prosthetic researchers want to know the direction their testing should take, I suggest they consider the specific reasons individuals with upper-limb amputations use prosthetic arms. I suggest that defining vocabulary, constructs, or tests, such as the Southampton Hand Assessment Procedure (SHAP), do not lead in the right direction to answer those questions. I suggest instead that more focus is needed on the particular tasks and scenarios that amputees encounter daily to determine which prosthetic devices will work. For more of my thoughts on the SHAP test, visit www.swisswuff.ch/tech/?p=3043 – Wolf Schweitzer, MD, is a forensic pathologist and faculty member of the University of Zurich, Switzerland, Institute of Legal Medicine. He also has a right transradial amputation due to a tumor. He uses a body-powered prosthetic arm in his job, which allows him to handle weights of up to 100 kg, work under a wide range of environmental temperatures, and be exposed to various fluids required in his occupation. Schweitzer has also tested other types of prostheses, including a bionic hand that lost integrity in its cosmetic glove covering after washing a car. He maintains a blog, Technical Right Below Elbow Amputee Issues, www.swisswuff.ch/tech
Links
- https://www.cybathlon.com/
- https://www.h-plus-h.ch/index.cfm?spr=0&hpn=4&sbn=5&idn=59
- https://kundertr.bplaced.net/wordpress/
- https://www.facebook.com/cybathlon
- https://actu.epfl.ch/news/cybathlon-3/
- https://www.wired.co.uk/news/archive/2014-03/27/cybathlon
- https://thrivesports.com/2014/03/30/switzerland-set-host-first-ever-cybathlon-2016/
- https://news.discovery.com/tech/robotics/2016-cybathlon-competition-designed-for-parathletes-140325.htm
- https://www.nccr-robotics.ch/page-102212-en.html
- https://www.myhandicap.ch/cybathlon.html
- https://www.balgrist.ch/desktopdefault.aspx/tabid-169/9_read-1376/
