Uncanny Valley

As an amputee looking for an arm prosthesis, you are limited to several options: You've got the standard silicone cover (stiff, lifeless silicone in a single color with minimal detail), the lifelike/realistic silicone cover (painted and sculpted to more accurately match your own anatomy), a few simple mechanical options (ie. the hook, or basic hands with simple grip), and the much more functional (and expensive) myoelectric/bionic options.  The last option is ideal for a person who wants to regain some functionality with their prosthesis, as they allow the wearer to to switch between several different grip patterns and hand positions for grabbing, pointing, pinching, and so forth.  Myolectric hands use sensors placed on muscles higher up in their arm to control the hand, allowing them to regain some (limited) manual dexterity from their new hand. The technology they are developing for bionic hands is reeeeeeeally cool and it has come a long way in the last few years.  We are starting to see the stuff of science fiction films become reality - Terminator and Iron Man and the like.  It's pretty gnarly. And as 3D printing and other tech continues to grow and become more streamlined, accessible, and affordable, the possibilities for prosthetics will continue to grow exponentially.  One of the biggest limiting factors in implementing myoelectric technology in prosthetics is the size and weight of the materials and mechanisms.  Companies like Bebionic, TouchBionics, and Ottobock are whittling down the weight and size to make myoelectric arms more user-friendly, and a MUCH more realistic option.


There is a certain amount of taboo associated with the loss of a limb or having some type of facial difference, which requires a prosthesis as either an aesthetic or functional solution.  This is especially true with facial prostheses, as people can immediately tell when something seems off or not-quite-right about a person's face.  This becomes even more glaringly obvious when a person is wearing a prosthesis that is poorly made.  Instead of covering up the area in question, an ill-fitting or poorly color-matched prosthesis draws attention to the fact that the wearer is missing a part of their anatomy.  This is the slippery slope of the Uncanny Valley.

Here's a quote and a nifty graph to explain:

[Masahiro] Mori's original hypothesis states that as the appearance of a robot is made more human, some observers' emotional response to the robot will become increasingly positive and empathic, until a point is reached beyond which the response quickly becomes that of strong revulsion. However, as the robot's appearance continues to become less distinguishable from that of a human being, the emotional response becomes positive once again and approaches human-to-human empathy levels.[9]

This area of repulsive response aroused by a robot with appearance and motion between a "barely human" and "fully human" entity is called the uncanny valley. The name captures the idea that an almost human-looking robot will seem overly "strange" to some human beings, will produce a feeling of uncanniness, and will thus fail to evoke the empathic response required for productive human-robot interaction.


Robots aside, this is a HUGE deal in prosthetics.  Many considerations need to be made when creating a prosthesis for a patient, and the skill of the prosthetist/anaplastologist needs to be exceptional. However, where facial prostheses need to be more realistic in order to avoid the Uncanny Valley, it's less of a concern with arm and leg prostheses.  In a way, we have the science fiction genre to thank for this because we, as a society, have been exposed to the futuristic idea of robotic, biomechanical, cybernetic organism (living tissue over metal endoskeleton) -type limbs for decades.  And because of this, we are primed for an evolution that can and will, ultimately, break the taboos surrounding artificial limbs.

The old-hat thought process that anything different is strange changes dramatically once a group of people takes ownership of these changes and embraces them.  Looking to amputees as an example, wearing an exceptionally strange or aesthetically interesting limb prosthesis changes the dialog surrounding what is "different" and "strange" entirely, and this only increases as prostheses become more functional.

Because of the era in which we live, having something new and interesting and innovative is cool, which gets people talking about it more, thus, changing what is deemed "normal" by social standards.  This is incredibly important because it means that the options for an amputee are only limited by the available technology.  And with the advent of 3D printing, the options for design are truly limitless.  Almost anything you can imagine can be created digitally and made into a physical object.  If you want a steampunk arm prosthesis with moving gears and a solar-powered USB port, you can have it!  And it's a wonderful conversation piece, which perpetuates the cycle of acceptance. And as long as there are individuals who are willing to flaunt the technology, and people eager to develop it, this idea will continue to grow and become more mainstream.

Luckily, there are some really innovative and interesting companies and people who are doing just this.  One group that comes to mind immediately is The Alternative Limb Project, which I have been following closely for the past few  years due to the INSANE quality of work that the founder, Sophie de Oliveira Barata, has been creating.  Her work is aesthetically very interesting, and great for patients who are interested in changing how the loss of a limb is viewed in society by engaging the public. Two projects in particular that AltLimbPro has been involved with have had really interesting results:

[youtube https://www.youtube.com/watch?v=jA8inmHhx8c&w=854&h=480]

[youtube https://www.youtube.com/watch?v=NZNFkMW9uFg&w=854&h=480]

These are both great examples of how people are taking ownership of their amputation in order to make something good and positive (and visually bad-ass!) out of it.  Since becoming involved in the prosthetics industry I have also been trying to get more involved with the people who are trying out new and experimental prosthetic technologies. Social media is an amazing tool, and I've had the opportunity to speak with a few people who are heavily invested, including James Young and Angel Giuffria (both of  whom are in the 2nd video). Following and interacting with them on Twitter has been really great because it has introduced me to even more people, groups, fabricators, technicians, and prosthetists who are like-minded, looking for innovative answers to these questions.

...Which leads me to my personal experience on the matter.  Over the last few months I've had the opportunity to work with a small group of people on a development team to create a new, customizable arm prosthesis system.  It's been a really interesting project to work on, mostly because of the sheer number of possibilities that become available to the patient with the system.  We use 3D scanning and printing, combined  with traditional silicone work to create customizable prostheses that are patient-specific.  I recently had  the opportunity to attend the OTWorld 2016 orthopedic convention in Leipzig, Germany, for the debut of the new  prosthesis, as well as to peruse the massive amount of prosthetic tech that was on display.  It  was incredibly impressive and a great way to become more familiar with what is commercially available to patients, as well as new technologies that are being developed.

But this post is getting a bit long, so I'm gonna make it a two-parter.  I'll put together another post very soon detailing the new product launch and OTWorld 2016, as well as childish photos i took of amusing German signs (hyuk hyuk hyuk).

Until next time!