How Engineers Use Your Neural Pathways to Program Prosthetics

Neural processors are the future of the prosthetic world, allowing more technology to be incorporated and restoring more function to the amputee or patient. There is a lot of science behind how they work, but also how this will impact the disabled community moving forward. 

Let's talk definitions for a minute. What even is a neural processor? What's a neuron? 

Well, neurons are the cells in the body responsible for receiving sensory input from outside factors, such as sound, pressure, vibrations, smell, and more. They are also responsible for transmitting this input to the brain as a way of controlling the body's reaction to outside factors. Read more about neurons here. 

Photo imaging of a series of neurons a brain from NPR

So what's a neural processor? 

A neural processor is a specialized circuit. It involves controlling and using math to execute machine functions, typically by using predictive models. These exist in digital devices, such as phones, computers, TVs, laptops, and watches. They also exist in cars, airplanes, trains, and more. 

For the brain, there is a more advanced version of an NP, called a neural net processor. It takes the understood workings of the brain, makes a model, and functions as a chip. It is also sometimes called a cognitive chip. Read more about NNP's here.

Photo of a net neural processor used in computers and prosthetics from Samsung.

So, how do NNP's and prosthetics go to together?

Scientists and Biomedical engineers have designed prosthetics using NNP's to read the brain's neuron transmissions in order to make the prosthetics function. NNP prosthetics can be used on patients only when there is enough salvageable nerve endings to make the prosthetic function. These prosthetics can be almost anywhere, from a finger to the partial leg to a full leg to a foot to an arm. Most commonly you will see prosthetic legs and arms because that is when the NNP comes most in handy. Below are some diagrams as to how different NNP prosthetic legs function! For more information about different prosthetic types, read this, and this, or this.

A description of a prosthetic leg with a knee joint that use a C-processor, which is a form of an NNP from Brown

A description of a prosthetic leg without knee join that uses an NNP to imitate feeling in the leg from the National Institute of Health

Diagram of a prosthetic hand with wrist joint that uses and N-processor (an NNP) from Slash Gear

So how are these developments making huge splashes in the disability world, both good and bad? Well some argue that the constant evolution of prosthetics to match the need is exceptional, and can restore function to the patient for necessary tasks to be self-sufficient.

 Another viewpoint is that pushing the development of prosthetics is harmful to the disabled community because it is a way of making them more suitable to the world, instead of making the world and our ways of life more accessible to people with impairments. While most people understand why this development in prosthetics is really important, it is still understandable that there is frustration about not being paid attention to except for science. Read more about disability resources here and here. 

Others are focused on another thing: cost. Prosthetics are expensive. Like really, really expensive. And for one with a NNP, the price typically quadruples, and most insurance only covers half of a regular prosthetic that needs to last two years. The average cost for a prosthetic leg without an NNP is $27,000, and with one, upwards of $70,000. And with the limited amount of money people are allowed to hold to keep disability insurance, that sort of money isn't feasible. The next step in research needs to be how to make prosthetics themselves more accessible to those who need them, and eventually how to mass produce ones with NNP's. For more about the cost of prosthetics, look here, and here, or here.

There are so many different opinions on both prosthetics and also biotic prosthetics, and I think they often cloud out the actual magnitude of how far the world has come in technology. It's miraculous that we can hook some wires up to some nerve endings and somehow, the brain can feel something that doesn't technically exist, as well as perform incredible tasks. Not to mention, the freedom little kids who had amputations now have, and adults late in life who lost limbs, and even those born with disabilities. It's a game changer. And also for people with phantom limb pain, which is a high rate of suicide in disabled patients, it can alleviate some of those symptoms. There are so many incredible facets of biotic prosthetics that we should give proper credit too! 

Thanks for reading, I hope you enjoyed, if you have any questions or ideas, email me at m.j.hedgepeth6@gmail.com !