From Sensors September, 1998 Pages 17 - 19. Electronic Hand Restores Movement to Paralyzed Limb The Freehand electronic hand is the world’s first prosthetic that promises to restore movement to a paralyzed limb. The $50,000 implant was developed over 25 years of research at Case Western Reserve University and is being brought to market by NeuroControl Corp. (Cleveland, Ohio), a company formed by the inventors of the implant. The components of the Freehand device are: 1. A shoulder position sensor that translates small shoulder movements into a control signal 2. An external controller (usually located on a wheelchair) that receives the control signals and processes the information into radio waves to power and control the implant through a transmission coil 3. A transmission coil worn over the implanted stimulator 4. An implanted pacemaker-sized stimulator that sends electrical stimulation to 8 electrodes 5. The electrodes that stimulate the muscles to contract, providing a functional hand grasp. Prosthetic Hand Promises Full Digital Movement The first prosthetic hand that will allow amputees to move the fingers independently has been demonstrated at Rutgers University and could be ready for production in a year. According to Carey Glass, a prosthesis consultant on the project and president of CC. Medical Inc. (New Brunswick, NJ), "We can start to think about wrist usage, elbow, even shoulder usage for people who have lost an entire arm." One amputee has so mastered the device that he can play a keyboard instrument with it. Conventional prosthetic hands have a metal claw or a soft-plastic hand with a thumb and four fingers, but only the thumb and first two fingers move. Moreover, their movement is limited to opening and closing at the same time. The prototype prosthetic at present operates only, the thumb, middle finger, and little finger, future models are expected to work all five digits. The system consists of the artificial hand; a silicon sleeve that is custom fitted over the lower arm; three sensors inside the sleeve; and wiring from the sensors to a computer and on down to the hand. Each sensor detects the motion of one tendon that would normally move a particular finger, and the computer then relays signals to that finger. Visual Implant Might Restore Sight to the Blind An implantable visual prosthesis being investigated at the Illinois Institute of Technology may eventually restore a version of eyesight to the blind. The research team is headed by Philip Troyk, associate professor of electrical and computer engineering. The implants would be used to electronically stimulate a person’s visual cortex, that part of the brain responsible for processing and analyzing light. The researchers are developing both the electronics and the hermetic packaging for the 1 in. long by 1 in. high by 1/4 in. long device. The unit consists of four ceramic submodules, each containing custom ICs controlling 64 channels, for a total of 256 channels. The hermetically sealed device would be placed under the skin of a patient’s skull; wires from the device would be inserted into the brain. A coil of wire worn on the patient’s head would both power and communicate with the device. After converting the original image to electronic form, the data would be transmitted to the visual cortex and the patient would see the images as points of light. The researchers hope that the plasticity of the brain will, over time, make sense of the information and allow patients to see areas of gray and whole images, not just points of light. The device may be ready for implantation within five years. The research is being supported by a three-year, $1 million grant from the National Institutes of Health’s Neuroprosthesis Program. ---------- Implant Offers Sight to the Blind From: R&D Magazine - October, 1998, page 122 Philip Troyk and his research team at the Illinois Institute of Technology, Chicago (312/567-6902), are developing a visual prosthesis which may enable blind people to visualize their surroundings. The implantable device electronically stimulates the brain's visual cortex so that it converts images into understandable electronic data. Patients using the device will first see only points of light, but researchers believe they will learn to create whole images from the patterns. The technology may provide blind patients with enough visual informatgion to work on computers. The devices are implanted in the patients' skulls and connected to their brains with wires. A coil of wire on the patient's head would serve to both power and communicate with the device. Composed of four ceramic submodules containing integrated circuits, each measuring 2.5 cm x 2.5 cm x 0.6 cm. Researchers believe that they will be able to deliver a working device in three years. The first of these prostheses may be implanted in patients within five years.