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Smart Implants for the Disabled

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PCQ Bureau
New Update

For many years Cyborgs were the stuff sci-fi movies were made of, the futuristic ramblings of a Hollywood director. And Arnold ‘the Terminator’ Schwarzenegger symbolized the pinnacle of cutting-edge technology, in a distant future world. No major progress was, however, made in the real world, until the mid-1990s, till the era of ‘micro-processing on a chip’.

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In the 1970s, when the concepts of bionics and cyborgs were first put forward, a simple circuit was physically large enough to be spread on a dining table and computers looked more like a bookrack and weighed a few hundred kgs. But, the last four years have seen a number of successful attempts in bridging the gap between man and machine. These can be classified into two streams.

l Experiments to help us evolve into super-intelligent beings like those being conducted by Prof Kevin Warwick (see page 32, PCQuest, November 2002) 

l Efforts to develop artificial sensing devices for the physically disabled

In 1998, Prof Warwick got a silicon chip transponder implanted into his left arm. The doors of the Cybernetics building at the University of Reading, UK opened for him and lights switched on automatically as soon as he reached them, thanks to the communication between the chip and the departmental computer. The computer was even programmed to say hello to him, first thing in the morning. Though his research explores mind-blowing future possibilities, we’ll look at research that directly benefits humanity now, thousands of disabled people worldwide. 

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Flashback to reel world. In Terminator 2, Schwarzenegger was ‘flesh over a metal endoskeleton’ with precise hearing that detected approaching danger and infrared vision that gave highly graphical 3D output like finding a perfect match to ‘borrow clothes’ from. Extremely powerful hands and legs made of hydraulic muscles and metal alloy working on signals from a microprocessor brain beat up competition into pulp or flung them out of the nearest glass window.

In the real world, bionics has reached only the stage of moderately successful implants for the heart, ear, eye, brain and spinal cord. From the now well-known cardiac pacemaker and artificial heart to more modern bionic ears, eyes, retinal implants, pain neutralizers and breathing pacemakers, the journey has been long

and not all that rewarding for many a scientist. 

A large amount of progress, however, has been made in the last four years or so thanks to corresponding R&D in IT also. Many of today’s successful products are made using commercially-available, off the shelf, IT products like microprocessors, IC chips, TV cameras, mikes, audio and video codecs and, of course, utilize advanced programming skills in embedded technology.

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Everyone can hear



Particularly successful have been companies like Clarion and Nucleus, which sell bionic ears. One example is the Nucleus 3 Bionic Ear. Here external sounds or noise are detected by a microphone and sent to a speech processor located outside the body, which analyses and processes them and then converts them into electrical signals. These electrical signals are then delivered to nerve cells in the cochlea (inner ear) using minute arrays of about 20 electrodes. The electrode stimulates the nerves inside the inner ear, which then transmits these signals to the brain where they are interpreted. The conversion of sounds into electrical signals, subsequent filtering to eliminate unwanted background noise and processing is taken care of by Nucleus R126 clinical programming software that runs on a ESPrit 3G or SPrint speech processor. Running on the SPrint speech processor is also the ADRO algorithm that continually processes the input to the speech processor so as to auto adjust the loudest sounds to comfortable levels and enhance soft sounds while eliminating background noise.

An illustration of Dobelle Institute’s artificial eye
The words Cyborg (Cybernetics organism) and Bionics (biology applied to electronis engineering systems) were popularized by the 1972 book, Cyborg by Martin Caidin.

Intelligent limbs



Remember Terminator’s long, and flowing strides without any jerks. Doctors have for long wanted to replicate that easygoing human-like motion in a cybernetic limb for amputees. C-Leg made by Otto Bock Health Care of Germany might just be the answer (competitors from MIT are also in the pipeline). It has four sensors that send data about 50 times a second to the two processors that operate it. Two piezoelectric sensors measure the pressure on the leg and the number of times the heel touches the ground, while magnetic sensors measure the angle of the knee which has to flex about 5—7 degrees each time the leg swings forward and the heel touches the ground. An internal Lithium ion battery keeps the hydraulic muscles of the C-Leg moving for up to 35 hours. The C-Leg which currently costs about $40,000 can be used to walk or even run on uneven terrain and downstairs. Climbing up is difficult though. Stability while walking or running is provided by embedded programming on the two microprocessors which reads data from the sensors and makes adjustments accordingly. 

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C-Leg’s claim to fame is the story of Curtis Grimsley, who used to work at the New York Port Authority office at the World Trade Center till 9/11. Grimsley had lost one of his legs earlier in a car accident and was fitted with a C-Leg. On the fateful day, Grimsley ran down 70 floors on his C-Leg like a normal limbed person to make a dramatic escape following the terrorist attack on the twin towers. 

Artificial vision



Less successful and more costly is Dr William Dobelle’s ‘artificial vision’ eye at $98,000 plus. This is made up of a small digital video camera built into sunglasses, a small wearable computer (120 MHz processor, 32 MB RAM and 1.5 GB

HDD) and associated electronics for processing the video signals and electrodes that transmits the processed signals to the cortex of the brain (see diagram). Though no where near the information overlaid heads-up display like sight of the Terminator, working prototypes allow the blind to see black and white displays similar to normal visioned people seeing LED scoreboards at cricket stadiums. The Dobelle Institute has been working with a volunteer codenamed Jerry for about 20 years before they debuted this artificial eye. As of now the vision is tunnel like and cannot be used for reading or writing, and is more like seeing shadows through a foggy glass. But given the pace of technological progress in the last few years, it’s not all that impossible that further miniaturization and improvements in quality in the future will allow successful commercialization for the benefit of millions of disabled people worldwide. 

Benoy George Thomas

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