The bionics revolution
Reality catches up with The Six Million Dollar Man
She’s short, dark, decked out in shiny black pants and a filmy chiffon blouse with trailing, delicate butterfly sleeves. Her fingernails, crusted in a shocking pink polish, match the color of the ring on the middle finger of her left hand. She walks into the centre of the busy laboratory, then stands patiently, waiting to be noticed. Finally, a stocky man, whistling Brahms while he works at an electrical bench, spies her from the corner of his eye. “How are you”? he asks.
“I’m fine,” she says, “but there’s something wrong with my arm.”
She drifts over to the workbench.
“Let’s have a look,” he says.
She grabs her left arm just above the elbow and pulls. It comes off in her right hand. She gives it to him.
The woman’s artificial hand is so lifelike, so useful, that it fooled an observer less than a foot away. It’s available off the shelf now from the burgeoning stocks of bioengineering: one major manufacturer has sold 13,000 like it in the past 10 years. It is almost a part of her: and yet it’s only plastic, sculpted in the shape of fleshy fingers, hiding a metal claw hooked to a tiny motor. The motor is triggered by the amplified electrical pulses coursing through the muscles in her partially amputated arm. The hand is battery powered. It is light. It has the same strength as a human hand. And it has released her from a constricted life, from silent, painful ostracism, into physical freedom.
Bioengineers call it a myoelectric hand. (Myoelectric means muscle electricity.) The first one was built in 1948, before the development of transistors, before the elegant intricacies of microelectronics. In the 30 years since, biomedical engineers, versed in the shrinking wonders of the electronics revolution, have ushered in the bionic age.
No one can yet produce bionic men and women who run like the wind or whose artificial arms have the strength of 10. But slowly engineers are building hard-wired replacement parts for missing arms, eyes and ears. Even in a time when technological innovations are commonplace, when sophisticated computers undreamt of 30 years ago are snapped up at the corner store for six bucks, the state of the art of biological replacement is nothing short of miraculous.
In the 1950s, the hottest news in a brand
new field was the cardiac pacemaker. A small battery powered piece of gadgetry, it has saved thousands of lives by keeping time for failing hearts, sending them a sharp jolt of electrical current every second. In the 1970s, it’s the brain pacemaker, a small device lodged inside the skull that triggers pleasurable feelings in the mentally ill. In laboratories in this country, the United States and around the world, biomedical research grinds ahead.
Bill Sauter has been up to his ears in myoelectric research since 1964. His lab is a small room in the bowels of the Ontario Crippled Children’s Centre in Toronto. A 16-year-old girl, with a wash of smooth skin where her arm and shoulder used to be (they were cut away in a cancer operation) tries on a new system Sauter has built for her. It has an electric hand and elbow. Both are supposed to move when she tenses two muscles in her back. While the hand opens and closes, the elbow buzzes like a trapped wasp. It’s jammed.
Sauter already has his hands full with the myoelectric future which is refusing to be born. He’s worked for the past few
years, with engineers Robert Scott and Robert Brittain from the Bio Engineering Institute of the University of New Brunswick, to make a hand that senses things. Sauter calls it a sensory feedback hand. That means it will tell the person wearing it what it’s doing. Today was to have been inauguration day. But something’s gone haywire.
Sauter, at 49, is small, bronzed, with crinkly brown hair and sharp brown eyes. He is bending over the new hand and sweating just a little. A cigarette dangles from the corner of his mouth. Bob Brittain is puzzled.
“Bill,” says Brittain, “I think we’ve got a problem.”
“No, you’ve got a problem,” snaps Sauter, “you did the soldering.”
Sitting by a workbench, waiting, is a slight, 19-year-old woman, Denise Lalonde. She’s been a “co-pilot” and research subject here for the past five years, ever since Sauter gave her her first myoelectric
hand when she was in grade nine. She’s had four more since then, but this feedback hand is the one she’s been waiting for.
Lalonde was born with a congenital defect. Her left arm is perfectly normal until just below the elbow. But where a forearm and hand should be, there is just a small, smooth, rounded stump. Growing up was painful. “I couldn’t skip rope, catch a ball and stuff like that,” she explains. So a hand that worked made a huge difference to her. “I wasn’t crying in my pillow all the time ’cause I was more accepted. The kids thought it was neat. And 1 thought it was just great.”
But this should be even better. Lalonde has a chance to be one of the few amputees in the world wearing an artificial hand with feeling. That’s always been the problem with myoelectrics. Even though they are controlled by muscle movements, because they have no sensation these hands, like Dr. Strangelove’s single-minded black fist, have to be watched. Carefully. “I have to be aware of it when Pm touching something,” says Denise. “I’m afraid I might crush it. If I take an ice cream cup and just hold it, the ice cream shoots out.”
Brittain takes this model apart to see what’s going wrong. He pulls the hand out of the pink, plastic forearm and lays it on a workbench beside Denise. He takes the electrodes out of the socket which fits around Denise’s stump in a vacuum seal. The electrodes look like fat, gold-plated quarters. Three are connected to the electronic amplifiers that pick up the muscle signal from her arm and control the flow of energy to the artificial hand. Another electrode takes the signal from the strain gauge and sends a zap of current to Denise’s skin.
Brittain straps the electrodes around her arm with some surgical tape. She sits down at the bench and begins to flex her arm. The hand, connected to the electrodes and battery with a few wires, and lying a full two feet away from her, whirs softly. The fingers fly apart, then close, open and close. Brittain inserts a roll of gauze between the thumb and forefinger. If the system is working, she should feel bubbles dancing across her skin.
“Bob, I don’t feel anything.” She takes the gauze roll out of the hand. Brittain adjusts the sensitivity on the stimulator electrode. He turns it on full. “There it is,” yells Denise, “it’s full speed ahead.”
“But you’re not doing anything. We’re getting somewhere, but I don’t know where exactly.”
That evening, Bob takes the whole arm apart, hunting for electronic gremlins. By the next morning he thinks he’s solved the problem. Denise picks the arm up from the workbench where it has been plugged into a charger, and slips her short stump into the socket. She flicks a switch on the side of the arm to turn the hand on. Nothing happens. She presses her own finger against the strain gauge in the artificial one and all of a sudden the hand takes on a life of its own. It springs open. There is a loud ratch-
etting sound. The whole hand is vibrating, shaking itself like a backfiring ancient Ford. Denise lets out a yelp and switches it off.
Denise fishes a new glove out of the large box on the table. It’s small, pale, fleshlike. The fingers are tiny, curled up delicately like a sleeping baby’s hand. As Sauter stretches it over the hand, Denise giggles about interference problems in the past. “When 1 took typing in school, we all had electric typewriters and my hand would go nuts.”
She slips the arm back on to test it out. The bubbles fly across her skin, the hand opens and closes silently. She grasps Bob Brittain’s fingers with her artificial ones
and gives them a hard squeeze. He flinches slightly. And then she walks out of the lab with her new sensory feedback hand, one of the first in the world.
Most of Sauter’s patienb come to him from the Workmen’s Compensation Board and are men and women crippled by industrial accidents. The psychological lift they get from a hand that works is enormous, the cost manageable. The hardware totals about $1,100. Building the socket to each amputee’s specifications is time consuming and expensive, but the final cost of the whole arm is $2,500.
There are problems. Patients must be trained to use these arms. They must be taught to consciously relax and contract
the muscle lying under the electrode. Not everyone can manage that. Unless the electrodes sit on the skin at exactly the right place, and stay there, the muscle signals won’t be clear enough to control the hand.
And then there are the amputees who can’t be helped with simple myoelectrics. If they have lost an arm high above the elbow there are too few muscles near the skin’s surface to control a hand, a powered wrist, an elbow. The answer for them, for the future, is to burrow beneath the surface of the skin, to put the electrodes right beside the signal source, on the nerves and muscles deep inside the body.
That’s why Bill Sauter and Bob Scott at the University of New Brunswick are waiting with excitement for word about an experiment in Edmonton. They know that Dr. Richard Stein of the University of Alberta is within a hair’s breadth of pulling off a coup. “If he can get the things he’s projecting and make it clinically usable,” says Scott, “it will be a tremendous breakthrough.”
Richard Stein’s lab in the medical sciences building at Edmonton’s University of Alberta is a multi-cultural hive. There’s Dr. Andy Hoffer, born in Uruguay, educated in the United States and now living in Edmonton “because Stein is here.” There’s Dr. Tessa Gordon, come half way round the world from South Africa, “because Dick Stein is here.” Then there’s the PhD from Denmark, the Canadian electronics expert and Stein himself. Born outside New York City 37 years ago, he trained in physics at MIT, then in biophysics and physiology at Oxford.
He backed into bionics (a word he heartily disapproves of—“it doesn’t mean anything”) out of basic research. He was studying the interplay, the complex inter-
relationship between nerves and muscles. He became interested in myoelectrics first (his lab has become a centre for people using them in Edmonton) and now he’s ready to take the next step. Stein wants to build an artificial arm controlled not just by muscles but by nerves.
If it was difficult to build small amplifiers sensitive enough to tap the tiny signals pulsing through muscles, listening to “the silent voices” of the nervous system is a herculean undertaking. Scientists have stimulated nerves with electrical current, made them fire on command, for more than 100 years. For almost as long they have been monitoring nerve signals in laboratory animals under deep anaesthesia.
But no one, until a few years ago, was able to listen in while animals, fully awake, were put through their paces. Three years ago, Stein and his colleagues found a way to put an electrode around a nerve without causing damage. They have been recording nerve signals from cats ever since.
If one can record from a cat going through its normal range of motion, twisting, flexing, jumping—and Stein can— then the same can be done with people. And provided the signal is clear enough, it can be used to control an electric limb. Last month, Stein and his colleagues took the first step toward that goal. They have put their system in a human subject, Herbert Sankey, an Edmonton apartment building manager.
Sankey, at 62, is tall, heavy, a sports fanatic with a shock of flame-red hair. His left arm was blown off during the Second World War. (“I also lost my watch and ring,” he laughs. “I should have picked them up but it just didn’t occur to me.”) He has a myoelectric hand (“It’s a part of me,” he says) but he still has a problem. He lost his arm too close to his elbow. There is no way for an external electrode to pick up signals from the muscles that once controlled his wrist, so he can’t use a powered wrist: he has to turn a locking joint to move his myoelectric hand into different positions.
On October 19, Dr. Lyle David, head of orthopedics at Edmonton’s University Hospital, opened Sankey’s left arm. In an operation lasting nearly five hours, he placed inside a group of platinum-iridium electrodes (long thin wires coiled around a Dacron thread) covered, except for the ends, by a clear plastic substance called Silastic. The electrodes were sewn on four different muscles. Two of them, near the surface of the arm, will open and close the hand. Two more, deep inside the arm, will control wrist motion in two directions.
The early results are more encouraging than Stein had hoped. While it will take years before the full implications are understood, Sankey has an artificial arm that sends feedback to the correct nerve, and a hand and wrist that can be controlled by
muscles he hasn’t used in 30 years. The feedback is much more natural than Denise Lalonde’s. The linkage between man and machine much more intimate.
Eventually, Stein should be able to use nerve signals to control the hand. This would be a major breakthrough. Stein and his electronics expert, Dean Charles, bubble with excitement when they look to the future. One day, nerve signals could be telemetered out of the body on radio waves, instead of traveling on wires through the skin. Patients could have a plethora of prosthetic options: researchers could build limbs with many different functions run off combinations of nerve and muscle signals. “If we’re working off the nerves,” says Charles, “there really isn’t any point in using an electric hand to run a typewriter. You could plug right into the typewriter itself. You could hook up to computers.”
But breaking through the surface of the skin is an invasion of a private inner world. And machine links direct to the nervous system carry a potential for abuse. Charles and Stein fret about possibilities of mind control in the future: in a recent journal article they published a clarion warning call. “We’re concerned,” explains Charles, “even though the initial application is for human benefit. You can easily see that it’s a powerful technique. When you tap into the peripheral or central nervous system, you’re essentially changing the information about the human experience.”
If feeding signals in and out of an elbow nerve generates fears for the future, what about research involving signals to the brain?
Dr. William Dobelle has been working for most of the past decade to create artificial sight for the blind and artificial hearing for the deaf. Dobelle, 36, head of the artificial organs program at ColumbiaPresbyterian Medical Centre, makes it clear he is only one in a long line of scientists who have tried to stimulate vision and hearing with a jolt of electrical current. Benjamin Franklin was one of the first. He put electrically charged wires on patients eyes and ears.
By the 1920s, the technology was a little more sophisticated. During succeeding decades neurosurgeon Wilder Penfield of Montreal confirmed that when he stimulated an area of the brain called the visual cortex patients reported seeing little spots of light called phosphenes. In the 1950s, a neuroanatomist suggested that these phosphenes might be harnessed to simulate vision. Few paid much attention. But in 1968, a British visual physiologist, Giles Brindley, reported on a startling experiment. He placed a group of electrodes on the visual cortex of a blind patient. The electrodes, triggered by an electronic implant under the skull, sent small trains of signals to the brain. He found that the phosphenes produced corresponded to the
patient’s visual field. Every time an electrode fired, a phosphene appeared in a specific place.
Dobelle was already working on the problems of the blind at the University of Utah but shifted his experimental emphasis to prostheses following Brindley’s announcement. For the first year he worked with animals. He and his colleagues were looking for the right form of electrical stimulation, so that they wouldn’t damage brain cells, and searching for implant materials that would neither be rejected nor chewed up inside the body.
In 1970, they began working with sighted patients undergoing a very special form of brain surgery that exposed the visual cortex. Dobelle organized contacts with 60 different medical centres across the continent. Dobelle and his associates would get on a plane and jet to operating rooms 3,000 miles away on 12 hours notice. By 1973, they had built a temporary implant.
Dobelle found that a blind patient, a man who had lost his sight in an explosion in Vietnam, could recognize squares, triangles and other simple shapes when electrodes were fired in the proper pattern. The experiments with permanent im-
plants two years later yielded even better results. Patients were able to recognize braille words, spelled out in glowing phosphenes, faster than they can read them with their fingers.
Dobelle has a long list of questions to answer before he goes on to the final implant, which will give him the ability to display more complex shapes to his patients. But he does have a rough blueprint for the artificial eye of the distant future. He will seal a microcamera inside a glass eye. The camera will pan with the movement of the eye muscles and send different light levels to a computer inside the frame of a pair of glasses. The computer will simplify the light signals and transform them to signals that can be sent to permanent electrodes inside the brain. The hardware cost, according to Dobelle’s engineers, would be $5,000.
Work with the problems of the deaf has proceeded along similar lines. Just as the visual cortex sorts out the electrical signals coming from the eye to the brain, so the auditory cortex sorts signals from the ear
into patterns of sound. If you stimulate the auditory cortex, patients experience bursts of sound called audenes. But the auditory cortex is difficult to reach. So Dobelle and his collaborators at the Ear Research Institute in Los Angeles have concentrated on something simpler. They are stimulating the inner ear with implanted electrodes. Deaf patients who have relatively healthy auditory nerves can distinguish between different pitches when a small current is run through the electrodes. Patients whose auditory nerves have been totally destroyed will have to wait a long time for an auditory cortex implant.
Last June a terse report popped up in the back pages of a Toronto newspaper. Few details were given, but it appeared that a neurophysiologist. Dr. Robert Heath of Tulane University medical school,had developed something called a brain pacemaker. The pacemaker had wondrous effects on the mentally ill. Heath explains that the pacemaker is “the first device of this type used specifically for behavior disorders.” The design is fairly simple. Electrodes are placed over the cerebellum and attached to a receiver placed over the chest. An antenna, taped on the skin above the receiver, is attached to a stimulator battery pack carried in the patient’s pocket. When the stimulator is on, electrical signals flow through the electrodes into the cerebellum.
These signals activate the brain’s “pleasure circuits.” While these pleasure cells are firing, the brain cells associated with “adversive emotion” (feelings like rage, fear, anger) are inhibited. The patient wearing the pacemaker finds his anger, fear or anxiety transmuted to warmth, happiness, euphoria.
The hardware costs about $2,000. Last year Heath implanted it in 11 violent, psychotic and neurotic patients. All 11 were considered “incurables” and were in hospital. One had spent 20 years on locked wards in Louisiana institutions. Most of them have now left the hospital and are able to work or at least live at home. One patient did not respond.
Since June, Heath has put pacemakers in 11 more patients, most of whom are doing well. He does not use it on patients who respond to other methods of treatment, tranquilizers or other psychotropic drugs. The technique is too new. But he does feel that in the long run it could become a preferred method of treatment. Drugs have side effects and they don’t always work. The pacemaker, so far, has no side effects.
It’s hard to quibble with those results. It’s hard to knock a device that returns “incurables” to a nearly normal life. While Heath likes to point out that the system is controlled by the patient, who can turn it on or off at will, he also admits that the pacemaker opens dangerous avenues. But no one, he says, has criticized him for opening up Pandora’s box.Ç?