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What developments do you see in prosthetic technologies that could better assist the warfighter?

Discussion Leader: 
Sliman Bensmaia, Ph.D.
Posted Date: 12/07/2015

This week's question is based on Feeling through a Bionic Hand, an article recently published in the HDIAC Journal. There have been several medical advancements in prosthetics, including enhanced sensors to restore the feeling of touch and microprocessors to increase fluid range of motion. The progress in state-of-the-art prosthetics can further improve the quality of life for military and civilian amputees.

Bionic Arm

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Comments

Hello everyone
I am a neuroscientist at the University of Chicago. For almost twenty years, I have been studying the neural basis of perception: How is the environment represented in the neuronal activity in the nervous system? My focus has been somatosensation -- the senses of touch and proprioception (the sense of where your body and limbs are in space). When we grasp and manipulate an object, we acquire a lot of information about the object through neural signals from the hand: Information about its shape, size, texture, and motion across the skin (if it's moving), for example. My lab investigates how this information is conveyed through patterns of neuronal activation in the somatosensory nerves, which carry sensory information from the hand to the brain, and in the brain itself.
Somatosensation is critical to our ability to use our hands to interact with objects. Without it, we are severely impaired. If we hope to restore to amputees or spinal cord injury patients the ability to manipulate objects, it is critical to replace somatosensation in upper-limb neuroprostheses. Almost ten years ago, we began leveraging what we have learned about how the nervous system represents tactile information to restore the sense of touch through electrical stimulation of the nervous system. The idea is that, if we know how patterns of neural activation convey information about objects, then we might be able to reproduce these patterns of neural activation by injecting small currents into the nervous system, and elicit sensations that convey information about objects manipulated with the prosthesis. In my lab, we develop algorithms that convert the output of sensors on the prosthetic hand into patterns of electrical stimulation delivered to the nerve (for amputees) or the brain (for spinal cord injury patients).

Sliman Bensmaia
Associate Professor
Department of Organismal Biology and Anatomy
University of Chicago

With emerging technologies such as lab-on-a-chip and organ-on-a chip, the ability to create organs in vitro could progress prosthetics. Growth and utilization of new skin, in conjunction with Dr. Bensmaia’s research, would create life-like prosthetic limbs with functionality and range similar to pre-event abilities. These technologies also increase psychological wellbeing; near full-functionality and human-like aesthetics increase self-confidence and support reintegration.

 

In some ways, what we do is like an organ-on-a-chip. We replace the receptors in the skin with sensors on the prosthetic hand. Then, we replace the computations that the nervous system performs on these receptor activations with our algorithms that convert sensor output into patterns of electrical stimulation (these algorithms will eventually be put on a chip, as we have done as a proof of principle in the past). The new skins are exciting developments in terms of sensorization and cosmetics, but the challenge we face is: How do we communicate information directly to the nervous system?

Sliman Bensmaia
Associate Professor
Department of Organismal Biology and Anatomy
University of Chicago

Prosthetic technologies have come a long way as far as development goes and their use in helping assist the warfighter. New developments in prosthetic technologies such as Dr. Bensmaia’s research in determining pressure sense and connecting electrical impulse back to the somatosensory cortex will allow for prosthetics to become even more functional. Many prosthetics have some battery components. With new developments in nanotechnology and nanocells, prosthetics can possibly be powered for longer periods of time without the need to recharge at inconvenient times. The marrying of many different technological advances will help with the development of prosthetics to assist the warfighter.

Great point. The development of the actual prostheses involves many innovations, not the least of which is how to power this thing for extended periods of time while keeping its weight within the range of a human arm.

Sliman Bensmaia
Associate Professor
Department of Organismal Biology and Anatomy
University of Chicago

I think developments towards making prosthetic technology look more life-like will be beneficial in assisting the warfighter. From a psychological aspect, it’s important to consider that seeing a robot-like prosthetic would have effects on the wearer and those around him/her. Having prosthetics that looked and felt like the real thing would positively impact the wearer’s self-esteem in addition to lessening the chance of the wearer being treated differently when getting acclimated into society.

Taking this one step further, even if the warfighter is not normally self-conscious of their prosthetic, a negative reaction from someone else may have a psychological impact on the warfighter. The ability to make prosthetics as life-like as possible will assist in reintegrating the warfighter back into society. One thing I have yet to see mentioned here is the use of tattoos on prosthetics. I have observed many veterans with prosthetics that had decoration, or "tattoos" on them as a way to personalize the device. The ability to carry this over into the life-like prosthetics may also be beneficial, allowing the owner to view it more like any other part of the body, and less like a device.

No question that cosmetics and aesthetics play a role. Some patients may enjoy having a clearly bionic arm, others may choose to to conceal that fact. Skin-like cosmeses have been developed to cover prosthetic limbs, and these are pretty convincing unless you look very closely. I do not see any reason why you can't add a tattoo on them!

Sliman Bensmaia
Associate Professor
Department of Organismal Biology and Anatomy
University of Chicago