London - When Luke Skywalker received a perfect bionic replacement for the hand that was cut off in Star Wars Episode V, the idea of replicating human organs and body parts seemed far-fetched.
Thirty years later, the idea is no longer just science fiction. Scientists, among them the creators of “Rex” - the world's most complete bionic man, unveiled in London this week - believe they can now replicate about two-thirds of the human body.
“We were surprised how many of the parts of the body can be replaced,” said Rich Walker, managing director of the robotics team Shadow, who built Rex.
“There are some vital organs missing, like the stomach, but 60 to 70 percent of a human has effectively been rebuilt.
“ This is heralded, then, as the dawn of the age of bionic man - although specialists caution that we are still feeling our way.
Social psychologist Bertolt Meyer, who also worked on Rex, has an interesting perspective: he was born without his left hand and has a prosthesis. “I have looked for new bionic technologies out of personal interest for a long time and I think that until five or six years ago nothing much was happening,” he said. “Suddenly we are at a point where we can build a body that is great and beautiful in its own special way.”
Not everyone in the field believes the recent progress, impressive as it is, places us on the road to complete replication of human limbs, organs and tissue. “We have motors which can lift things but, if you want to mimic the dexterity of a hand, we are not there yet,” said Professor Steven Hsiao of the John Hopkins University in Baltimore.
“What we are beginning to achieve is building prostheses which look like human body parts, but we are a long way away from making ones which relay sensory information the way the human body does.”
Professor Hsiao drew the comparison between Star Wars and real life, saying: “The goal is the scene in the film where Luke Skywalker gets his new hand tested and is able to feel pain: we are not there. In 10 years, we will be able to build a robot which has the dexterity to pick up a pen and write with it, but it will not be able to send back sensory information.”
Rex, billed as the pinnacle of robotics achievement to date, will meet his public at the Science Museum in London. Dubbed the Million-Dollar Man (that's how much he cost to make), he consists of a prosthetic face, hips, knees, feet and hands, all of which are commercially available. Other off-the-shelf items include an artificial retina, cochlea and heart.
Rex's other internal organs, among them a pancreas, a set of artificial lungs and bladder, are still in development. Some of the technology cannot work without human input; bionic hands, for example, need muscles and signals from the brain to function. Other parts, such as the heart and pancreas, are designed to work on their own.
Other body parts remain out of the reach of scientists. Mr Walker says: “The only artificial stomach we have seen is very large and generates electricity, so you couldn't use it to replace a human stomach, but I am sure there are people in the regenerative medicine community working on that.”
And replication of the human brain, the most complex structure known to man, was not even on the radar, Mr Walker said. “This is a showcase for prosthetic parts, it shows exactly where we've got to in being able to replace parts of a human.”
Bertolt Meyer adds: “I'd say it's highly unlikely that, in our lifetimes or in that of our grandchildren, we will see a fully articulate human body with an artificial intelligence.”
Mr Meyer said there would be ethical issues surrounding prostheses if they began to outperform human body parts. “Should I be allowed to cut off my real hand and replace it with something, does that gives me an unfair advantage over people who cannot afford this? I'm not saying that is going to happen but these are questions that should be on the table before that technology becomes available.”
BIONIC MAN
REPLACEABLE PARTS
EYES
Video cameras mounted on glasses pass data to electrodes placed on the retina, which in turn send signals to the brain. The patient can learn to interpret these shapes and patterns into images.
LUNGS
Still in the prototype stage, prosthetic lungs are designed to match the oxygen and carbon dioxide needs of a patient via surface-coated hollow polymers.
HEART
Made of light, durable plastic and powered by a wearable, battery-powered driver, artificial hearts provide ample blood flow through both ventricles and could reduce the need for pacemakers.
KIDNEY
This small prototype removes toxins from the blood using nanoscale filters. In years to come it is hoped it could help reduce the need for dialysis.
PANCREAS
An algorithmic device likened to a car’s GPS system, it releases insulin in response to rising blood sugar levels. In the future, it is hoped this could replace traditional injections for Type 1 diabetes sufferers.
FEET
These reflexive prosthetic feet mimic the actions of the Achilles tendon via springs that sense the ankle’s position, allowing the user to propel forward and recreate the sensation of natural movement.
EARS
An inner-ear implant which simulates nerve fibres processes signals captured by a sound processor and relays them to the brain.
TRACHEA
A foam-like structure consisting of tiny pores is used to produce an artificial windpipe. In 2011, the organ was successfully implanted in a cancer patient from Sweden.
SPLEEN
Resembling a flexible plastic wafer, this porous chip filters out pathogens into a solution, cleaning infections. There are difficulties in modelling the sequence of blood flow to each organ, but the US military hopes it could eventually be used to treat sepsis in injured troops.
HANDS
Durable aluminium framework allows the user to perform hand gestures and can be custom coloured to blend with skin tones. The user can exert correct pressure in speed and grip via electrical signals.
ARMS
This prosthetic limb is capable of 26 degrees of movement through silent ‘freeswing’ and Bluetooth communication for fine-tuning. Activated by tiny bursts of electrical signals from muscles in the user’s stump, it can reach and grasp for an object at the same time.
BLOOD
‘Plastic blood’ is a dark, honey-like substance which has a longer shelf-life than donated blood and is immune to infection. For now however, it remains confined to the experimental stages. - The Independent