The Future of Prosthetics

[rs]

Hello

I am a product designer from London, I am writing an essay about the future aesthetic of prosthetics and the part fashion may play.

What I would love to have is some feedback on my thoughts and research, if anyone is interested in talking to me please PM me.  

Thanks

Rory

[allenuk]

Said it before, saying it again.

Most of us (can't speak for all) don't give a flying fig what our prostheses LOOK like.

Our prime concern is whether or not they WORK as prosthetic limbs.

If you have a choice between designing products that work better and ones that look better, then we (there I go again - most of us) would rather you concentrated on the former.

Sure, once you've solved the problem of painful, badly-fitting sockets, and given us ALL sockets we can put on in the morning, work/walk/get on with life all day until we take them off in the evening, THEN move on to how nice they look.


Allen.

[cherylm]

Well, I'm going to partially agree/partially disagree with Allen. Absolutely, positively, without a single doubt, fit and function means much, much more in a prosthetic limb than appearance. However, probably because I've been really fortunate in getting prostheses that fit and function well for me, I do have some degree of interest in how a prosthetic limb might look in the future. Note that I said "SOME"...it's far from the most important thing in my life. My current prosthesis is a vacuum assisted suction suspension with a lovely little design laminated on my full socket. If there were a way to better incorporate the vacuum pump in the design or improve the articulation in my ankle, or create a lighter, cooler, easier-to-wear socket for a below-knee prosthesis, those would be improvements in both fit/function and appearance that I'd be interested in.

That said, I'm also not sure that there IS any sort of agreement as to what might be wanted in what the prosthesis of the future should do/be/look like. Even in the current world of prosthetics, there are those of us who want something that looks as close to a "real, true, natural" leg or arm as possible. Some of us actually want to look as "high-tech/bionic/robotic" as possible. Some of us want to make an "artistic statement" with our prostheses. And on, and on, and on.......

So, function and fit first...and perhaps a "flexible" appearance after...?

[SteveInMd]

I'd certainly agree with the sentiments of Allen and Cheryl. Prostheses that "just work" without pain or instability or awkwardness are vastly more important than anything else. Appearance and aesthetics are minor in comparison. On that issue, though, I tend to favor "bionic" rather than flesh-like. To me, artificial limbs that mimic flesh just end up looking sad and creepy.

A significant point that is missed by a lot of designs, though is the weight and size of the foot. In my case, my natural foot was a men's size 13 (US sizing). An artificial foot that size on my first leg just felt like I was swinging around a brick on the end of my lag. Sheer bulk is an issue with stairs and getting in and out of cars, too.

My prosthetist was very reluctant to make my second leg with a much smaller foot. But he acquiesced. I'm very happy with the decreased weight and bulk of my size 9 foot on the right. So, yeah, I have to get shoes of two different sizes, but that waste is a relatively minor inconvenience.

Now, I just need to find a guy with a size 13 right foot and size 9 left, and we can use each other's spare half-pair shoes. :-)

The reality seems to be that an extra ounce of weight in the foot is much more of a problem than the same weight placed higher, in the socket, because of the swinging motion of the leg. Thus, designers who seek to reduce weight of a prosthesis design should really focus on making the foot light and stable, rather than life-like.

[rs]

This is really helpful feedback, thank you. In the future the fit and tech of prosthesis is only going to get better.

How many people are interested or like the Scott Summit/Bespoke fairings: www.bespokeinnovations.com/content/gallery

Fairings that clip over your existing prosthesis. I understand this will add weight though, but is it worth it? If these can be interchanged for the situation or how you feel, is this something that people might like?



This is what I believe to be a more possible concept for the future rather than a fully designed minimal functioning design.


Alexander McQueen's Solid ash prosthetic for Aimee Mullins.

[cherylm]

I've seen the Bespoke Fairings, and I think that they are beautiful. I've felt them, and they generally seem to be lightweight. I love the idea of being able to match a prosthetic limb to your activities and/or what you are wearing...especially since I can't do much in the way of variety in shoes (yeah, yeah...women and shoes...I know...) having that possibility of "prosthetic variety" is like a lovely dream.

A STANDARD MEDICAL INSURANCE POLICY IS NEVER, EVER GOING TO BE WILLING TO PAY FOR "PROSTHETIC VARIETY."

I've even heard of some insurance policies that won't cover a standard foam-and-stockings cosmesis...which I find unfair to those who do want a leg that doesn't call attention to itself. I wore a standard cosmesis when I was still working in an office, but went "naked/bionic" after I retired. I feel more "real" without the foam-and-stockings...but that's just me.

Until all these lovely, innovative "pretty prostheses" can be made practical AND AFFORDABLE/PAYABLE UNDER INSURANCE PLANS, they are nothing more than an elusive dream to us.

That said, the solid ash leg is incredibly beautiful. Sigh.............

[cherylm]

BTW, SteveInMd, have you checked into finding an "odd shoe exchange" in your area? They do exist, and you may well find someone wears your sizes "in reverse."

[allenuk]

Alright, I'm going to have to spell out my objections a bit less obliquely.

Paint your cosmesis as you like, cover your prosthesis with whatever you like - your leg, your choice, and if it pleases you, that is A Good Thing, without a doubt.

But the idea that intelligent young people (I'm speaking of the UK, but I think the same applies elsewhere) should BOTHER spending their time, energy and education concentrating on the aesthetics of a product which in fact needs fundamentally redesigning, and until it actually WORKS well for 99.9% of its users, strikes me as a waste of time and energy.

Bah, humbug, etc.


A

[SteveInMd]

Jan 28, 2014 4:27:58 GMT -7 allenuk said:

....

Bah, humbug, etc.


A

Well, as someone who also struggles with a leg that basically works fine, but is still somewhat awkward and uncomfortable, and ill-suited to long walks, I agree.  Prosthetic appearance is what we end-users may play around with, but an intelligent designer of these limbs really needs to focus on the biomechanics of a good device.  The market for swappable coverings, etc, is tiny and relatively frivolous.  

I have to say, the images above reminded me of the leg-lamp from the semi-obscure film "Christmas Story":


There are actually a lot of thoughts I'd like to share about end-user small modifications I've done or planned in my half-year as an amputee.  Since it's in the broad rubric of prosthesis design, this may be a reasonable thread to start.

I'm really "tickled pink" with my latest.  I've felt my set-up needed some padding and filler in the bottom of my BKA socket.  Many amputees/prosthetists avoid putting any of their weight-bearing on the end of their stump because the area can be super-sensitive.  It can't ever be the only spot on the leg for weight-bearing, but with good cushioning and shape/support many of us can do well with a bit more weight-bearing there than happens in a common socket shape.  The O+P industry includes silicone pads that can go inside the liner (or outside, if there's no pin that would have to go through it to engage).  But the cost to a prosthetist is somewhere near $50, and they don't sell to end-users.  I'm a severe do-it-yourselfer, and toyed with the idea molding one from commercially available silicone resin, but found an inexpensive solution that probably works better than any one-size-fits-all silicone pad:


You get two pads for the price. I got a pair like this for $7 (including shipping) from an e-bay seller in Hong Kong. Just pull the hard plastic bit out of the silicone.  The side that goes on the stump is nicely curved to fit, has a light, hypo-allergenic adhesive, and the edges taper nicely to paper-thin.  Very, very soft.  About 1 cm maximum thickness in my size-D cup.  Fits perfectly.  My socket is significantly more comfortable with this inside my liner.

And to think some people have dismissed my ideas as the product of a boob!

Steve

[allenuk]

Steve: now THAT'S what I call design!

I've been poncing about with 2nd Skin Gel pads for some years now - they work, but only up to a limited point, and break down after a few brief hours, but the breast implants sound as if they'd work for me too.

You can get silicone pads from the likes of Ossur, but they tend to be far too hard, and don't shift around like real human tissue, so next stop e-bay.

I'll report back.


A.

[allenuk]

Right, so I got my d-cups (very fetching) - found a place in the north of England, and mine cost under ten bucks inc. shipping, so very cheap, also very quick via eBay.

Can you give us some tips on separating the gel part from the harder 'skin' layer? Or don't you separate them?

Advice welcomed, please.

A

[SteveInMd]

Good ol' proboards, where middle-aged guys get together and compare notes on their silicone bras. ;-)
The one I got has a very soft "skin" -- reading the details, it's polyurethane, with silicone gel inside.
Only the clasp was hard, and I just pulled it out. It sort of feels like a water balloon with a little bit of shape to it, no edges at all.

I gather yours has somewhat stiff protruding edges, perhaps. I doubt you could extract the gel from the skin, I'd think trimming the edges down would be better.

Now, since my previous posting, I got another package in the mail. My own socket feels to me rather cavernous in the bottom third, with the top part of the socket quite snug indeed. Like my leg is the clapper of a bell, swishing around at the bottom, fixed at the top. That's not because of stump shrinkage, it just seems to be the way my prosthetist likes to make them.

So in my case, I decided to try out a whole "mastectomy form," size 5. Rather generous, though not mimicking Pamela Anderson. In my case, it actually seems to work rather well. When bearing weight, my leg settles down a couple of centimeters into the gel, which I suppose isn't ideal, but it's definitely an improvement over no gel at all. Haven't decided yet whether its better or worse than the smaller silicone bra half.

More experiment reports to come as they happen.

Steve

[allenuk]

Well Steve, you must have some BIG legs over there! I tried the d-cup, and my tiddly little stump (I'm 270 pounds) just sits in the middle of it.

For the time being, I've tried just chopping some gel off (I did get the same gels as you - misunderstanding over the 'hard' bits) so that it fits between stump and liner, but it's not right, so I've ordered an a-cup version, which if the first was anything to go by, will arrive tomorrow.

I like the principle of gel padding, particularly in the case of my very boney stump - I walked miles and miles in the first year or so, while I still had loads of natural padding, but as that's worn off, it's now Bone vs. Socket, and any help like gels is thus appreciated.

The gel pad which Ossur market is supposed to do a similar job, but not sure if you can buy them unless you're a medical professional, otherwise I'd try those.

I shall let you know if the a-cup version works any better.

Good luck!


Allen.

[SteveInMd]

Perhaps you got false breasts instead of a silicone bra. My original post was about a silicone bra--relatively thin material. It would feel to be slightly less than 1 cm in maximum thickness.

But the second item I described is actually a false breast. Yes, it's a fairly massive mound of soft silicone. The fact that I can stuff the thing into the bottom of my liner, and still get my leg into the socket fully, and have the thing feel better--it's pretty clearly an indictment of the excess space inside the bottom of my socket. Which is probably 60% from shrinkage of the stump, and 40% from my prosthetist's habits of how to fabricate a socket.

Before long, I'll need to find a new guy whose philosophy about fitting is more flexible, and more inclined toward a "total weight bearing" socket instead of a "patella tendon bearing" socket.

[allenuk]

No, I followed the photograph you posted, and got 'Un Bra's (there's some tangled grammar for you). So it is just the same, just a misunderstanding re the hard bits.

But what I can't understand is this enormous gap at the base of your stump!

www.youtube.com/watch?v=uxj3PjGthQs

...is a youtube video of me demonstrating 2nd skin gels on my stump, and I only quote it here so you can see how my liner fits on my stump, which then hits the bottom of my socket.

Which is how ALL bka stumps/sockets that I've ever seen work - and I've been in and out of prosthetic fitting rooms for 9 years now. I've never heard of any CP building in such a huge hole!

How the heck does your pin-lock work? Is your stump still in contact with the base of the socket, or does it dangle above it? Do tell, I'm fascinated (and a bit worried I must say).

But anyway, it might be that the bra liners are just too thick for my minimal gel requirements - a couple of 2nd skin gels fills up my 'gap' quite adequately!

We do have a resident CP here, name of Ted, but he only pops in occasionally, more's the pity. Hopefully he'll pick up on this thread and make professional comments.

Allen.

[allenuk]

I got the A-cups the next day as predicted, but still MILES too big.

But I cut out the very central part of one of the cups, about 2.5 inches across, and I'm currently trying that stuck on to my pointey stump - the built-in adhesive is gentle enough yet sticky enough to stay put.

So far, very good. Thicker than my usual 2nd Skin gels, but nice and 'squelchy', and unlike the 2nd Skin gels, I think it'll stay in one piece for quite a long time. (The gels disintegrate daily!)

More reporting as it happens.


A

[allenuk]

Well, so far so very good - not perfect for preventing some slight discomfort where stump meets socket, but a vast improvement on my 2nd skin gels - it's just a question of cutting the right shape, and I've now got so many bra inserts that I have more than enough squelchy gel to be getting on with.

Medical silicone might be a tad better, but this is the closest I've come so far to a material which mimics the leg tissue that we're all missing.

I owe you one, Steve!


A

[stonecutter]

I am thoroughly confused about what you're doing with these things. I have an issue where my tibial end hits the front if the socket.

This is the problem with the non-plaster casting. My guy uses a scanner and computer to take the shape of the stump but it doesn't pick out what parts are soft and what parts are hard in the stump. That translates into a sore tibial end. Some days it even cuts the callus that has formed. An stopping to prop the stump away from the socket using cardboard, paper towel or whatever I have on hand isn't always possible.

Anyway. A bit more info would be awesome.

[snarfler]

Gentlemen please if I may. I must say, in my tenure as an amputee, I too have "Re invented" the wheel many times. What I have as an advantage is that as a licensed Engineer I knew how to approach the problem systematically. Already well versed in variable plane geometry, I needed to see what products were available to the Prosthetist. Using my business credentials, I opened accounts with several suppliers to the industry such as Cascade. Now armed with an arsenal of parts catalogs, I could apply what I know of problem solving to my own needs.

Allen and Steve,
There is a simple kit available that can convert your PTB sockets to very comfortable Full contacts. A small interface is installed in your socket. You don the leg but don't stand on it. Then an injector applies resilient silicone into the socket between you and the distal area. A short time later, you stand and enjoy a cozy cumfy "First Generation" fit that will last for years.

Trevor,
I am sorry to say that your practitioner made a mistake. Your socket was not properly loaded. He failed to take the step where he reduces or adds to the initial molding and cast to provide relief for the Tibia and Fibula. A very typical and nonrecoverable mistake. It's rarely discovered in the test socket as you don't wear it long enough to cause pain. This socket will vex you until it's replaced. I have seen people remove the offending area with a hole saw. While this works temporarily, it quickly destroys the liner. Your practitioner may be able to unload the area by way of alignment but then your foot won't be in the perfect position. Sometimes softening the heel strike can help. Be very cautious as continued pressure can result in deep skin blistering and possible infections.

As to the initial topic,
These are just my opinions based mostly on my own experience and suffering and the information I've gained from other Amputees. I am not a Prosthetist and only offer opinions. The process of making an artificial limb is unique to the individual. Just remember that a prostheses does not have to hurt. It should fit well and function perfectly without pressure wounds blistering or pain. I have no regard at all to it's appearance and agree that any time spent on such a thing would be a pointless endeavor.

[SteveInMd]

Great commentary!!!
Stonecutter, your socket sounds exactly like my first socket. Same spot. My guy first sanded down the inside on the sensitive spot, then cut a hole clear through. That actually did the trick nicely. But a hole does present an edge to wear at the liner. I suppose a layer of duct tape applied to the *inside* could help that. But a re-casting would seem to be in order, as snarfler says.

Snarfler, we're blessed to have an engineer here in the discussion. I'm just an amateur. I've thought about the injection-molding concept you've described. On a meagre budget, I've thought about using plaster-of-paris, or the polyurethane foam in an aerosol can available at the hardware store, or buying some "eco-flex" soft silicone resin. I still might try one of those, but I've got some other plans I'm working on.

Allen, yeah, I guess I have a hefty stump. I'm 6'3" and 250 lb (190 cm, 113 kg). My "good" leg has a maximum calf circumference of 38 cm, and my stump is 42. I just now realized how absurd it is that my prosthetist has had me struggling to pull on a size 28 liner !!! Since the socket was casted with my bare leg, but I wear it with a very tight liner, a lot of the fleshy stump is squeezed upwards, leaving a cavity in the bottom of the socket and a *very* tight fit above.

So the "D" cup silicone bra piece is actually a little skimpy on the bottom of my stump. But I can see why a "B" might be a little wide for someone less well-endowed. ;-)

The whole silicone mastectomy "form" though, was too much silicone. It felt fine, and my leg only rode about a cm higher in my socket, but the loss of stability was bad. Walking a few blocks, I had to twist the leg around to face front every 10 steps. Cutting some off, the soft silicone inside prooved to be increadibly soft, gooey, and sticky. Applying medical paper tape to the gooey surface restored it to a usable consistency.

[stonecutter]

I finally understand what you're doing with these 'appliances.' I had thought you were using to cushion your stumps on the vertical surfaces...

My issue is something different entirely.

[allenuk]

Feb 3, 2014 22:45:02 GMT -7 snarfler said:

.....

Allen and Steve,
There is a simple kit available that can convert your PTB sockets to very comfortable Full contacts. A small interface is installed in your socket. You don the leg but don't stand on it. Then an injector applies resilient silicone into the socket between you and the distal area. A short time later, you stand and enjoy a cozy cumfy "First Generation" fit that will last for years.

Snarfier: could you give us more detail about that?

First, what's a PTB socket? Don't think we have that term in the UK.

Second, the interface etc. Is this a commercially-available thing, or just bits and pieces? Either way, I'd like to hear more about it.

And as to your general point about prostheses not having to hurt, couldn't agree more, except that mine has, not quite from the off, but certainly as I lost my body tissue and ended up with skin and bone, it's always hurt a bit.

I've had MRIs, CTs, Xrays, etc., looking for a nerve-ending reason for the pain, without success. And like Steve, I've had various windows cut into my sockets, which have helped - but not in the case of the point of my stump. A window there would interfere with the pinlock mechanism, or so I've been told.

Good to have your engineering input.


Allen.

[snarfler]

Perhaps it would be best if I were to start a new thread as we digress. Please look for, "Applied Physics 101" in this section of the Forum.

[allenuk]

Feb 5, 2014 13:15:40 GMT -7 stonecutter said:

I finally understand what you're doing with these 'appliances.' I had thought you were using to cushion your stumps on the vertical surfaces...

My issue is something different entirely.

Steve's and mine are also different from each other. He's putting a pad between his 'window' and socket/leg, whereas I'm putting a cushion pad right at the bottom tip of the stump, neither purely vertical nor horizontal - mine folds over that 'point' of cut bone, similar to the youtube video I link to above.

It is working, better than other gels, and its prime purpose is a tissue substitute - i.e. where the liner doesn't do its job too well, a bit of extra 'tissue' can stop that bone/skin/socket rubbing.

A

[stonecutter]

Hmmm... Extra tissue - was part of the reason I had to have my revision surgery! Hope that doesn't come to bit me in the(stump)!