"Bionic Arm" Technology from the Rehabilitation Institute of Chicago

This week, the Rehabilitation Institute of Chicago introduced the first woman to be fitted with its "bionic arm" technology. Claudia Mitchell, who had her left arm amputated at the shoulder after a motorcycle accident, can now grab a drawer pull with her prosthetic hand by thinking, "grab drawer pull." That a person can successfully control multiple, complex movements of a prosthetic limb with his or her thoughts opens up a world of possibility for amputees. The setup -- both surgical and technological -- that makes this feat possible is almost as amazing as the results of the procedure.

The "bionic arm" technology is possible primarily because of two facts of amputation. First, the motor cortex in the brain (the area that controls voluntary muscle movements) is still sending out control signals even if certain voluntary muscles are no longer available for control; and second, when doctors amputate a limb, they don't remove all of the nerves that once carried signals to that limb. So if a person's arm is gone, there are working nerve stubs that end in the shoulder and simply have nowhere to send their information. If those nerve endings can be redirected to a working muscle group, then when a person thinks "grab handle with hand," and the brain sends out the corresponding signals to the nerves that should communicate with the hand, those signals end up at the working muscle group instead of at the dead end of the shoulder.

Rerouting those nerves is not a simple task. Dr. Todd Kuiken of the RIC developed the procedure, which he calls "targeted muscle reinnervation." Surgeons basically dissect the shoulder to access the nerve endings that control the movements of arm joints like the elbow, wrist and hand. Then, without damaging the nerves, they redirect the endings to a working muscle group. In the case of the RIC's "bionic arm," surgeons attach the nerve endings to a set of chest muscles. It takes several months for the nerves to grow into those muscles and become fully integrated. The end result is a redirection of control signals: The motor cortex sends out signals for the arm and hand through nerve passageways as it always did; but instead of those signals ending up at the shoulder, they end up at the chest.

To use those signals to control the bionic arm, the RIC setup places electrodes on the surface of the chest muscles. Each electrode controls one of the six motors that move the prosthetic arm's joints. When a person thinks "open hand," the brain sends the "open hand" signal to the appropriate nerve, now located in the chest. When the nerve ending receives the signal, the chest muscle it's connected to contracts. When the "open hand" chest muscle contracts, the electrode on that muscle detects the activation and tells the motor controlling the bionic hand to open. And since each nerve ending is integrated into a different piece of chest muscle, a person wearing the bionic arm can move all six motors simultaneously, resulting in a pretty natural range of motions for the prosthesis.

Courtesy - " science.howstuffworks.com "

Then why can one create a Robot that is controlled by a human brain!!!

How to weave machinery into biology

As we’re starting to test artificially grown organs, scientists are wondering how to make sure that their methods result in viable tissues. One of the first steps was to take organ growth into three dimensions, letting the cells grow on a scaffold and self-organize into the right muscles, valves, and other soft tissue. Usually these scaffolds are derived from existing organs purified of all their old cells and many are designed to break down into naturally occurring chemicals to be flushed out of the body on implantation. But how do you check what the organ can be implanted with the necessary level of precision? Why turn the scaffold into a monitoring device by letting cells grow on a sensor. This way, when the tissues grow, you can monitor the electrical buzz between the cells and track how well they’re developing and working together. But so far, this method had a pretty sever limitation. It could only be done in two dimensions, one less than we need for viable organic structures. So much potential but so problematic to implement.

Well, researchers at MIT decided to tackle this problem and came up with a new biocompatible material that could be arranged into a proper three dimensional scaffold and monitor both the structure and function of an organ. After successfully growing cardiac muscles around a mesh of this electro-sensitive substance, they were able to monitor the effects of a chemical that speeds up heart rate. Using their method, we could obtain a treasure trove of new data about how well a future artificial organ will grow and run it through a battery of tests to make sure it’s fit for clinical use to replace a damaged or failing organ. Even more interesting would be the opportunity for doctors to keep monitoring how the organ is doing and give patients advance warning should a health crisis be imminent. Imagine a future in which your aging and failing vital organs could be replaced with wired versions of themselves and report on how well your body is doing, giving all sorts of useful warnings should something new go wrong. Better yet, the mesh would simply read the behavior of the cells around it and report it back to a system which can make sense of the detected patterns so there’s not delicate, over-engineered instrument sitting inside you.

And all that brings us to another question. Could nanoparticles made from this material hitch a ride through a patient’s bloodstream to the liver, lungs, heart, kidneys, possibly into some key parts of the musculoskeletal system, maybe even the brain itself (though that would be a major challenge in and of itself), and monitor his or her health by listening to the patterns of electrical signals emitted by the organs’ cells. Could be a path to early detection and treatment of cancer strains that grow into tumors when we learn how to track the electrochemical signs of a malicious cell being formed? The possibilities posed by this technology are really quite amazing and come with great potential for new medical markets. Let’s hope there will be a lot of follow up to see if it really would be possible to make us all cyborgs with internal biocompatible sensors that will help us better diagnose what ails us as our bodies accumulate wear and tear. It sounds an awful lot like a science fiction movie, true. But in this case, the technology is very real and we have some very good ideas out there for how to turn it into science fact with the right funding and expertise behind this invention’s spin-off projects.

See: Tian, B., et al. (2012). Macroporous nanowire nanoelectronic scaffolds for synthetic tissues Nature Materials DOI: 10.1038/nmat3404

Courtesy : Weird things