Real World Cyborgs
Real Word Cyborgs
Dateline: 06/13/00
If you were convinced that cyborgs live only in the imagination of the science fiction writers, here is another example of how technology is converting yesterday's SF into tomorrow's reality. Several research labs are working on a hybrid device in which a body of a robot is controlled by the organic "brain." I'm sure this research will raise many ethical issues, but let's stick to the tech-side of a story first and see what can we expect in the near future.
Vittorio Sanguineti of the University of Genova, Ferdinando Mussa-Ivaldi, Simon Alford and Bernie Reger of Northwestern University in Chicago are taking an interesting approach in developing what they call an "artificial animal." They are using a brain tissue from the sea lamprey as the control system for the robot module. Most people are familiar with the lamprey as the uninvited parasite that attacks native fish, but this time it serves as a highly important model system for understanding vertebrate locomotion. Its nervous system is comprised of standard vertebrate cell types and structures, but contains orders of magnitude fewer neurons than modern vertebrates. Another primary advantage of lamprey's neural tissue for experimental neurobiology is its robustness, allowing for long-term animal experiments which are very difficult in the modern vertebrates.
Hoping to understand the principles underlying the control of biological systems, the research team took a multidisciplinary approach that involves a combination of techniques deriving from fields of neurophysiology, mechanical engineering, mathematics and computer science. They extracted a lamprey's brainsteam and spinal cord and used that tissue for controlling a commercially available Khepera robot. Light sensors mounted at the robot module feed the sensory information to the organic part of this hybrid. The command signals are generated here and transferred to the robot's motors, turning the robot in response to its environment. The brain tissue itself is located off-board in a salt solution and connected to the robot by wire. As a result of this experiment, complex emergent behaviors were reported in response to the simple light stimuli. More information will be available in the proceedings of the Seventh International Conference on Artificial Life (1-6 August 2000) - see the article titled "Connecting Brains to Robots: The Development of a Hybrid System for the Study of Learning in Neural Tissues."
Understanding how brain cells communicate with man-made machines will have much wider implications than were expected just a few years ago. Think about sophisticated prostheses, sensing devices and artificial organs: technology will make life much easier for (but not limited only to) disabled people. One of AI visionaries, Ray Kurzweil, said that within three decades neural implants will be available that interface directly to our brain cells. But we don't have to wait such a long time - some devices are already in use or waiting for the Food and Drug Administration (FDA) approval. For example, Artificial Silicon Retina from the Optobionics Corporation is a silicon chip approximately 3 mm in diameter and 1/1000 inch in thickness. It contains thousands of microscopic solar cells called "microphotodiodes," each having its own stimulating electrode. These microphotodiodes are designed to convert the light energy from images into thousands of tiny electrical impulses to stimulate the remaining functional cells of the patients retina. When surgically implanted under the retina, the ASR is designed to produce visual signals similar to those produced by the photoreceptor layer.
Other artificial vision systems like the "Dobelle Eye" are providing independent mobility to blind people. It consists of a sub-miniature television camera and an ultrasonic distance sensor, both of which are mounted on a pair of eyeglasses. The sensors connect through a cable to a miniature computer, which is worn in a pack on a person's belt. After processing the video and distance signals, the computer uses sophisticated computer-imaging technology, including edge-detection algorithms to simplify the image eliminating "noise." The computer then triggers a second microcomputer that transmits pulses to an array of 68 platinum electrodes implanted on the surface of the brain's visual cortex. The patient in the study reported in ASAIO Journal is a 62-year-old male who was totally blinded by trauma when he was 36 years old. After learning to use the system and "read" the display, the patient was able to read two inch tall letters at a distance of five feet and navigate in unfamiliar environments including the New York City subway system. By replacing the sub-miniature television camera with a special electronic interface, the patient is also learning to "watch" television, use a computer, and gain access to the Internet.
For a clear presentation of information about cochlear (inner ear) implants, including information about their history, some of the current controversies or questions, as well as some of the misconceptions regarding implants, see a monograph by William F. House, owner of AllHear, a company that manufactures cochlear implants. The most sophisticated devices, brain prostheses, are produced by companies like Medtronic, Inc. and Cyberonics, Inc. to control neuromuscular tremor and epileptic seizures.
Researchers from the <Emory University have developed an electrode brain implant that is allowing speech-impaired patients to communicate through a computer. The neurotrophic electrode is implanted into the motor cortex of the brain using a tiny glass encasing. Recording wires are placed inside the glass cone to pick up the neural signals from the ingrown brain tissue and transmit them through the skin to a receiver and amplifier outside of the scalp. Neural signals are used to drive the computer cursor in the same way a computer mouse is moved back and forth. The recorded neural signals are connected to the computer and are used as a substitute for the mouse cursor. The patient learns to control the strength and pattern of the electric impulses being produced in the brain, and after some training is able to "will" a cursor to move and then stop on a specific point on the computer screen.