Ask Slashdot: What Would You Look For In a Prosthetic Hand?

Arglebarf writes "A family member is recovering from a serious illness and, unfortunately, the medication that saved her life will probably cost her hands and feet. She is an artist by trade, so this is a pretty big deal. Replacement prostheses might restore a degree of independence, as well as enabling her to continue with her creative passions. Do any Slashdotters have experience with replacement hands? What features do you look for? Do any models allow you tweak the software for fine tuning? Beyond the day-to-day uses, she will want something that can hold small objects precisely (e.g. a paintbrush)."

Comments

Re:What do I look for in a prosthestic hand?

[Jeremiah Cornelius]

Self lubrication.

I'd look for a transplant

[Brandano]

If at all possible. It isn't too far fetched, hand and forearm transplants have been made, and have even achieved sensorial feedback.

Re:I'd look for a transplant

[Anonymous Coward]

There is no doubt in my mind that for now, transplant wont be an option. It is experimental and, probably more important, risky. I don't think you can be a candidate until you are stable and able to bear the stress of the transplant. The kinds of illness which she may have are unlikely to be compatible with all the surgery and anti-rejection drugs needed for transplant.

Dean Kamen - Luke

[iiii]

Dean Kamen, inventor of the Segway, has been working on much more functional prosthetics. He named his bionic arm "Luke", an obvious reference we can all appreciate. Demos of it look pretty amazing. Here's the official page for it: http://www.dekaresearch.com/deka_arm.shtml Also google "Kamen Luke Arm" and you find lots of pix, vids and articles about it.

Re:Dean Kamen - Luke

[TubeSteak]

If you want something you can actually buy:
http://www.touchbionics.com/products/active-prostheses/i-limb-ultra/

It runs ~$100,000 and is more or less top of the line.

Re:Dean Kamen - Luke

[sp332]

I used to work at DEKA. I didn't work on the Luke arm, but I got to talk to the engineers and a couple of early adopters. I think it is a great idea for an artist. The arm's controls are modular. They accept many different kinds of inputs, and the actions are even programmable with macros. You can get hand, wrist, forearm, elbow, upper arm, or shoulder configurations. It is as light as a 50th percentile female arm (including the batttery!). It's precise enough to pick up a grape without crushing it. It allows enough finesse in multiple degrees of freedom to allow a double-amputee to eat cereal without spilling it (which Dean Kamen jokes even he can't do :) I saw a guy use a macro to control an electric drill to handle the changing torque while he controlled how fast the drill went. I think it would be a great choice for an artist.

Mouth will probably work better than prosthetics

[Big_Breaker]

For paint brushes and other small items I imagine holding them in her mouth will work better than current prosthetic hands.

You may be thinking about the robotic hands you can see in research clips but most available prosthetics are simple devices that open and close with a turn of the forearm.

The robotic hands suffer from difficulty getting a "close/open hand" signal from the brain. Implanted electrodes are all to some degree incompatible with human tissue and degrade over time. Sensors to read electrical signals through the skin are imprecise. Some versions use buttons manipulated by other body parts (likely toes in this case) but these are not in the mainstream.

The old fashion two finger hooks seem to be the most practical answer for a lot of people. They are cheaper, durable, don't require batteries and can do a lot of useful things with any fine motor manipulation.

A human hand is a marvel of biological engineering. Sadly it is tough to replicate in a prosthetic. Perhaps she would be a good candidate for a transplant down the road? Prosthetics may improve more quickly with so many vets having suffered limb loss. To date lower limb prosethetics seem to be well ahead of hands/arms in terms of matching the original limb's functionality. Lots of "below the knee" single amputies have no obvious impairment in terms of gait.

Upgradability, replaceability & interchangabil

[schwep]

Technology is moving very fast. State of the art today won't be in 5 year. I would want a system that I could disconnect the replacement part(s) and connect up new ones without surgery. This also allows for custom limbs for specific tasks. Holding a brush may be a custom limb. I may also want a custom chainsaw arm, too.

I want flexibility for change & all the specifications for the mating connector to my body to be open source or license/patent free so I can have custom limbs made. I want a copy of the specs for the same reason.

What kind of artist?

[50000BTU_barbecue]

If you need touch, you might want to consider Krukenberg hands, which are gruesome to Westerners but are often the only viable option for many people.

I'll let you google it whenever you feel ready. Some people are more sensitive than others.

Re:What kind of artist?

[Miamicanes]

After reading about them, I can't help but wonder whether an interesting prosthetic compromise might be to somehow attach muscle fibers to implanted force-feedback strain gauges, then use the strain-gauge readings to control the hand itself (possibly in conjunction with all-electrical sensors used with other nerves to provide additional control. In other words, instead of pulling on bones, the muscles would pull on artificial ligaments cemented onto strain gauges attached to some kind of stretchy/springy plastic that itself is attached to a worm gear that moves the far point closer or farther from the muscle to alter the resistance.

For finer control (like individual fingers), it would take an idea from the way HTC's hybrid mechanical-capacitive switches used on their last few Windows Mobile and early Android phones worked. Basically, they used capacitive means to determine WHERE (approxiamtely) you were touching the phone, but used an actual switch triggered by a press anywhere in the region to determine when you actually intended to fire a switch event.

In a similar manner, the hand's controller could attempt to discern things like individual finger control by sensing the nerve bundle directly to come up with blunt motions, but sanity-check it in realtime against the muscle-triggered strain gauge, and use fuzzy logic to correlate patterns of nerve activity with specific variants of strain-gauge muscle tension to produce an intended action (so the actual finger, for instance, curled in direct response to the real-world forearm muscle pulling on the implanted strain gauge).

The problem with non-mechanical nerve interfaces is that they basically have the same kind of problems that capacitive touchscreens do... terrible signal to noise ratio and processing latency compared to real-world direct actuation. Nerves aren't like switch-triggered wires in a harness... they're more like a bundle of coax carrying multiplexed spread-spectrum QPSK signals with unbelievable amounts of background noise. By directly interfacing a few muscles with strain gauges, we can bypass the hundred (give or take) years of R&D it's going to take to get signal processing up to the point where it really needs to be, and just take advantage of the signal processing that the forearm muscles ALREADY HAVE to pick out the right signals and translate them into commands for the prosthetic hand.

Re:Opportunity?

[ttucker]

I can't be the only one who's thinking it needs to support a Fleshlight attachment...

This prosthetic hand is for a woman, who is going to lose her hands. Are you fucking serious that this is the best thing you can think of to say?

Re:What do I look for in a prosthestic hand?

[Anonymous Coward]

so... another vote for self lubrication

I have an idea.

[Anonymous Coward]

Ask the fucking prosthetics guy that will get/make her a new one when the time comes. I mean he is qualified to actually give opinions. How many people on here that would respond to you are going to actually have a prosthetic or even know anything about how they work/perform in the real world? None. Im sure some will say they have one or "Know a friend of a friends former roomates neighbor that one" but bottom line is they don't know dick.

This question is as stupid as asking for legal advice online in a murder trial. Its the internet, 98% of your answers will come from people who don't know shit but think they do.

Re:I have an idea.

[Arglebarf]

When purchasing a computer, I could just ask the "fucking computer guy" at the shop. Alternatively, I could look around at all possibilities to see if some components or capabilities would suit me better than the standard options. Yes, that requires me to filter out a ton of nonsense from the responses, but I have the patience of a saint (which also helps with the trolls).

Re:I'd look for a transplant.. another alternative

[Anonymous Coward]

http://en.wikipedia.org/wiki/Krukenberg_procedure

SAVE THE NERVES! Sorry for shouting but...

[Anonymous Coward]

Sorry for shouting. But save the nerves. I run a regen med research lab, and there is lots of cool stuff coming down the pipe. I know, I know, Real Soon Now, but advancements are on the way. The big limitation is going to be nerves though. No matter how much cool stuff we put together with artificial bone and patient-specific stem-cell derived muscles etc, it's all moot if you can't control it properly, and the nerves, for a variety of reasons, will be the hardest part to regenerate.

Fortunately, there has been some really interesting work done in terms of rerouting the nerves (both motor and sensory) - basically, if the nerves don't attach to anything, they die. But, if before you amputate, you take the nerves and move the ends over so they now lie against skin and muscle etc that will not be amputated, the cells remain alive (and functional). This has lots of interesting applications in terms of interfacing with prosthetics, but also in 5 or 10 years (or longer, if so - sorry, everything is often slower and more complex than we hope), this means the nerves are still there, waiting to be connected to the regenerated limb. Here is one paper that discusses it in more detail:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2685921/

I don't want to give you too much false hope about where the technology is going - I am very excited about the potential, but there are still a number of obstacles. So, live for today, but there is hope for tomorrow as well.

MU

Re:Mouth will probably work better than prosthetic

[complete loony]

My dad lost both hands and most of his forearms as a child. He has always preferred to use his own stumps as-is, rather than mucking about with prosthetics. But then he learnt to use his arms at an early age, and he was determined to do everything he could.

He can do practically everything you or I could do, except for things he simply can't reach or that require juggling to many things too rapidly. He has the neatest "handwriting" of anyone I know, he types by holding a pen, he can drive a car, develop software, and he's built a house extension. As an adult he's always been a productive member of society.

While you may develop the dexterity to use a prothethic. Don't discount the potential usefulness of your remaining limbs just as they are.