Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

field of audiology, giving back the gift of hearing to the deaf. These artificial cochleas work by connecting electronic hardware with biological “wetware,” that is, neurons. The cochlear implant has several components. A microphone is placed outside the ear. It receives sound waves, processes them, and transmits the signals by radio to the implant that is surgically placed inside the ear. The implant receives the radio messages and converts them into electrical currents that are sent down electrodes in the ear. The cochlea recognizes these electrical impulses and sends them on to the brain. These implants can use up to twenty-four electrodes and can process half a dozen frequencies, enough to recognize the human voice. Already, 150,000 people worldwide have had cochlear implants.
    Several groups are exploring ways to assist the blind by creating artificial vision, connecting a camera to the human brain. One method is to directly insert the silicon chip into the retina of the person and attach the chip to the retina’s neurons. Another is to connect the chip to a special cable that is connected to the back of the skull, where the brain processesvision. These groups, for the first time in history, have been able to restore a degree of sight to the blind. Patients have been able to see up to 50 pixels lighting up before them. Eventually, scientists should be able to scale this up so that they can see thousands of pixels.
    The patients can see fireworks, the outlines of their hands, shining objects and lights, the presence of cars and people, and the borders of objects. “ At Little League games, I can see where the catcher, batter, and umpire are,” says Linda Morfoot, one of the test subjects.
    So far, thirty patients have had artificial retinas with up to sixty electrodes. But the Department of Energy’s Artificial Retina Project, based at the University of Southern California, is already planning a new system with more than 200 electrodes. A 1,000-electrode device is also being studied (but if too many electrodes are packed onto the chip, it could cause overheating of the retina). In this system, a miniature camera mounted on a blind person’s eyeglasses takes pictures and sends them wirelessly to a microprocessor, worn on a belt, that relays the information to the chip placed directly on the retina. This chip sends tiny pulses directly into the retinal nerves that are still active, thereby bypassing defective retinal cells.
    STAR WARS
ROBOTIC HAND
    Using mechanical enhancements, one can also duplicate the feats of science fiction, including the robotic hand of
Star Wars
and the X-ray vision of Superman. In
The Empire Strikes Back,
Luke Skywalker has his hand chopped off by a lightsaber wielded by the evil Darth Vader, his father. No problem. Scientists in this faraway galaxy quickly create a new mechanical hand, complete with fingers that can touch and feel.
    This may sound like science fiction, yet it is already here. A significant advance was made by scientists in Italy and Sweden, who have actually made a robotic hand that can “feel.” One subject, Robin Ekenstam, a twenty-two-year-old who had his right hand amputated to remove a cancerous tumor, can now control the motion of his mechanical fingers and feel the response. Doctors connected the nerves in Ekenstam’s arm to the chips contained in his mechanical hand so that he can control the finger movements with his brain. The artificial “smart hand” has four motors and forty sensors. The motion of his mechanical fingers is then relayed to his brain so he hasfeedback. In this way, he is able to control and also “feel” the motion of his hand. Since feedback is one of the essential features of body motion, this could revolutionize the way we treat amputees with prosthetic limbs.
    Ekenstam says, “ It’s great. I have a feeling that I have not had for a long time. Now I am getting sensation back. If I grab something tightly, then I can feel it in the fingertips, which is strange, since I don’t have them anymore.”
    One of the researchers, Christian Cipriani of the Scuola Superiore Sant’Anna, says, “First, the brain controls the mechanical hand without any muscle contractions. Second, the hand will be able to give feedback to the patient so he will be able to feel. Just like a real hand.”
    This development is significant because it means that one day humans may effortlessly control mechanical limbs as if they were flesh and bone.