The telephone ringing distracted Sara from the soap opera she was watching. Her husband John went to the other room and answered it. Sara turned her attention back to the TV. A few minutes later John returned to the room with a curious look on his face, not angry or happy, just curiously different. ÒThat was your neurosurgeon,Ó he told her, Òhe is looking for a test subject for an experiment, and thought you might be the perfect candidate.Ó
Sara is a quadriplegic. She had been severely injured when a drunk driver forced her off the road. After months of hospitalization, and over a year of rehab treatments, her life had stabilized to the point that she was now confined to a wheelchair. She required 24-hour care, but at least she was home now. She had been fitted with a special motorized chair that had a control system that worked when she blew into tubes positioned near her mouth. She had a little movement of her neck and head, and her internal organs were working, but she had no use of her arms or legs. Sadly, for both Sara and John, she also had no feelings below the base of her neck. Fortunately, John still loved her very much, in spite of her handicapped body, and although her life was not anything like it had been, she was glad to be alive.
John began to explain the details of the phone call. Her surgeon had a friend who was a professor at MIT. Together they were working on an experimental interface that would allow nerve signals from the brain to be received and transformed into electrical signals. These, it was hoped could then be used to activate robotic arms, legs etc. Sara's part in the experiment would be as the test subject. She would be fitted with the interface, and would then go through a series of tests to study the possibilities of bionic equipment that might make her life easier. The doctor had assured John that there would be no medical procedures involved, and that she could decide at any time to bow out if it was too much for her. Better yet, the surgeon and his friend could do the tests right here in town, so she didn't have to travel far to be their test subject.
Sara agreed, and the arrangements were made, and on Monday morning, she wheeled onto the platform of her handicap van, and John drove her to the hospital. After introductions, Michael, her surgeon, and Jared, his friend, proceeded to explain the first test. To connect to the unbroken nerve cells, it would be necessary for Sara to wear an abbreviated form of neck and back brace. This circled her neck and extended down her back, with a strap around her chest to hold it in place. The neck collar was quite thick as it contained the electronic devices necessary for the interface. Exiting from the back of the collar was a ribbon cable that connected directly to the computer. Once this was all in place, Michael told them that the computer would use the collar to search for the individual nerve cells by means of a scan. Once the location of the nerve endings had been identified, the electronics would lock on to those locations and the interface connection would be complete. It is for this reason, he said, that it is important that your neck not be able to move.
Once she was strapped into the collar and brace, the computer was turned on and the program was set in motion. To Sara, nothing seemed to be happening, she felt nothing. While this was going on, Jared brought out a long bar with a series of different coloured lights. This would be the initial test medium. It was connected to the computer, and when Jared plugged it in, a white light went on. Michael asked Sara to bend her left big toe. ÒI can't move anything below my neck,Ó said Sara, Òand now not even my neck.Ó Michael was patient and said for her to imagine that she was moving her big toe. She closed her eyes, tried to lean back a bit in her neck collar, and suddenly the white light went off and a red one came on. ÒGood,Ó said Michael, Ònow relax your toe.Ó The red light went out and the white came on again. ÒNow let's try the right toe.Ó This time the green light came on. ÒNow your right hand.Ó The blue came on. ÒLeft hand?Ó The yellow came on. ÒBend your left knee.Ó Orange. ÒRight knee.Ó Purple. The test was working and they had run out of colours. Michael and Jared were ecstatic and were shaking hands and congratulating each other. They then explained to John and Sara that their idea had worked. Sara's mind was able to send nerve impulses to the ends of her damaged spinal cord, and the electronics in the interface collar had been able to read them and produce the change in effect. ÒThat's great, if I want to put on a light show, but where do we go from here?Ó asked Sara. ÒAh!Ó said Michael, ÒThat's the other reason why we asked you to be the test subject. Since John is a robotics engineer, we asked if he would help us so that you could interface to items such as a robotic arm, of his design, of course. I believe that by the time we are all finished that you will be able to live much more independently than you do now, and others will also benefit from our research.Ó
Life returned to normal for the next month as John set to work designing and building a robotic arm. To save time he used a standard prosthetic hook for the hand. He built an extension to attach to the back of Sara's wheelchair, and installed the arm so that it started just above her right shoulder. The bones of the arm were metal tubes, and they were hinged at the elbow and wrist. Attached to the outside of the tubes were servo motors with rack and pinion gears in the places where muscles should be. These were attached to stainless steel cables that were acting as the tendons. There were also several multi-coloured bundles of wires connecting everything together. It wasn't pretty, but it was ready for testing.
The next test required the combination of the light bar and the arm. Sara was again put into the collar brace and the interface connection made. First Jared asked her to open and shut her hand. The yellow light went on and off. Jared made some changes to the wiring and asked her to do it again. This time the hooks on the arm opened and shut. Everyone was immediately excited; it was working. They then went through the various movements of the arm, rotating the wrist, bending the wrist, bending the elbow, raising the arm straight forward and to the side. Each time a different coloured light came on, and Jared made the necessary wiring changes. Finally, all the correct connections had been made and Michael had her go through a series of tests to see how much control she could put on the arm. Everything was working very well and she did not seem to have any trouble ÔthinkingÕ the arm to function. She discovered, for example, that she could think the arm to raise, not straight forward or to the side, but in between at any angle she chose.
Then, by accident, the most amazing and unexpected thing happened. With her arm out to the side, John moved forward to make an adjustment on the arm. He stumbled over something on the floor and fell against the arm. ÒOuch!Ó yelled Sara, and everyone, including Sara was dumbfounded. ÒWhy did you say that?Ó Asked Michael. ÒBecause it hurt,Ó said Sara. Now considering that the arm was attached to the chair and not to Sara herself, except through the interface, they all concluded that she had actually received biofeedback through her nervous system. Several tests were done with Jared bending the joints on her arm, without telling her to. Each time she felt her brain telling her ÔnoÕ. John then knew he could build this feature into her arm so that she could feel what the arm was touching. This would also make her arm more useful, and seem more realistic.
John got to work on a second arm while Sara played with the first. Every day she discovered that she could do more things than before. She no longer needed the breath controls for her chair as she could use her arm to move a small joystick controller. By the time the next arm had been installed and tested, she had two arms that she could not only use, but that could interact with each other. Holding something heavy with both hands was now possible and she could even sense the weight of things. The arms were still attached to the chair, and still looked very primitive, but John had plans for the next step.
Sara was a fairly tall, but slight girl, who had trained for triathlons before her accident. She now tried very hard to maintain a limited diet so that she would not get fat. The inactivity of her limbs, of course, had caused her muscles to waste away completely, leaving very thin arms and legs. John's next challenge would be to build prosthetic arms that enclosed Sara's real arms. This would not only look better, but the movement of the robotic arms would carry the real arms along, keeping her joints flexible. These new arms required two layers of covering, one snug on her arm and one covering the mechanics and electronics of the arm. John made plaster casts of her arms, and then used them to make models around which to build the arms. The structural part of the arms, he decided, would be on the back half of each section and would contain the Ò muscleÓ servos, control cable ÒtendonsÓ, hinged joints, and electronic wiring. This would be attached to what looked like a hockey player's shoulder pads, but with the built-in neck collar interface. The top half on each segment would close in the real arm, and give a smooth surface to the finished arm. John asked Sara if she wanted it to be silver or flesh coloured. ÒOo!Ó she said, ÒSilver, or chrome!Ó She knows John has a thing for robots, and the shinier the better.
Once her new arms were ready, a new test was required to make sure all the wiring was connected correctly. The new arms were too heavy for Sara's wasted body to hold them up, so they were attached to the back of the chair, just behind the shoulders. To get Sara out of them for bed, the half panels on the lower and upper arms would be removed as well as the front of the shoulder section. The neck collar had always opened at the front to be removed. A laptop computer was now permanently attached to the back of the chair, along with the battery pack for the arms. In the morning the process was reversed, and a few keystrokes on the computer and she was up and running for the day. These arms still had prosthetic hooks for hands, with Sara's real hands curled up just behind them inside the forearm. John's next challenge would be to make more realistic, working hands, with thumbs and fingers. Unbeknownst to Sara, he was also working on the lower body and legs.
As time passed by, Sara became more and more familiar with her arms, and was beginning to think of herself more as a paraplegic than quad. She was able to do a lot with her hooks, as she could not only clamp things and bend her wrists, but could rotate them nearly 360 degrees, more than a natural arm. One day John announced that the next phase of her test was ready at the hospital. She was not aware that he had taken moulds of her legs one night as she slept, and he actually had legs ready for her as well. The hips attached to a back brace that would also hold her arms. Once she was placed in the leg portion, the arms were detached from her chair and bolted to the leg portion. This was still a prototype, so again the legs were not as finished as they would be later. Again the test routine with the lights and the necessary wiring, and now for the big test. For now Sara was attached to the computer and a large battery pack with a sort of umbilical cord, but refinements would come once they were sure it would work. Sara moved her feet and ankles and knees and hips as Jared made to correct connections of the wires. Again the interface functioned flawlessly, and soon, with help, Sara was able to stand up. On her first foray, she had to sit back down right away as standing made her dizzy, but after a while, she managed to stand, and then take a few halting steps. Again the men cheered and high-fived each other, as they could see dollar signs in their eyes. This robot assist would be worth millions as a commercial product for people with handicaps.
Sara wanted to wear the suit home, but many refinements still had to be made, so the arms were disconnected and she was placed back in the chair with only the arms. John promised the next test would result in her being able to go home in the next model of the suit. Time passed and finally the day came. As she entered the room at the hospital, she saw a gleaming Ôsuit of armorÕ standing beside the bed. Sara couldn't wait to put it on. The men laid it on the bed, opened the front panels, and then carefully lifted Sara into it. Sara saw that the arms now had thumbs and fingers, which her hands were slid into like gloves. Once all the covers were closed and locked, Sara was totally covered except for her head. The entire suit was shiny chrome, and the surfaces were very sleek and sexy. John had obviously put a lot of love into this suit and she asked him for a kiss.
Once again the usual interface tests had to be performed, but this time there were no lights or exposed wiring to connect. The last test had established all of these, and only the usual nerve search and connection by the interface in the collar had to be done. Sara immediately sat up and began to ÒfeelÓ herself all over. She raised her hands and admired the sleekness of her fingers. She wiggled each one, and they all worked as if they were real. John had even moulded long metal fingernails into the tips of her fingers. She touched herself on the hips, and reported to the men that she could feel her body through the biofeedback of the suit interface. As she moved her hands up her body, she was surprised to find that her breasts were quite large, much bigger than real. Is there a reason for these, she asked her husband, with a quirky little smile. Actually, yes! John replied. We wanted your suit to be self contained so that you would have complete mobility, which required on-board lithium-ion battery packs. Most of them are placed around your thighs. As your real legs are so wasted away, the batteries flesh out the thighs and fill up what would otherwise have been empty space. There is a nearly invisible access panel for a miniature computer, in front of your ribs, just below the breasts, but we had to find a place for its batteries. Can you guess where they are?
Michael brought a full length mirror out and put it in front of Sara. She smiled as she looked at what she had become. The suit was sleek and chrome plated, and because of her thin wasted body, she was able to have a trim sexy figure and still have room for the mechanics of the suit. In fact, she was wearing one exoskeleton inside another, with the ÒmusclesÓ in between the layers. She asked questions about what life in the suit would be like. Taking it off and putting it on would require help, and it would require a quick new interfacing each time. John said that the only time she would really need to take it off would be to bathe, and as she hardly perspired at all, probably once a week would do. She could sleep in it without any problem. The area between her legs had a neat little sliding door that allowed her to once again use a regular toilet. ÒHooray, no more bedpans,Ó she cheered.
Life for Sara returned to as close to normal as she ever could have expected. She could do almost anything that she could do before, except swim. Once she got used to the suit she could even jog for short distances, and ride her bicycle again. For her birthday, the following month, John brought her a present. It was the last part of her suit. He asked her to lay down on the bed and spread her legs apart, which she did with no problem. He slid her trapdoor open and slid a tube-like rubber object into her. On its rim it had a built in plug that connected to a similar plug hidden under the rim of her suit. Of course Sara couldn't feel it sliding in, but wow did she ever feel it when the plug was attached. She realized that this was an artificial vagina and it was wired to be sensitized for sex. She pulled John down to the bed and reached over and shut off the light.
Later John made Sara two more pieces for her suit. A helmet, just for fun, so she could pretend that she was a real robot, and a new panel for her belly that had a soft area that could expand as needed.