Rebuilding humans using bionics
Key text
This topic is sponsored by Sir Mark Oliphant International Frontiers of Science and Technology Conference Series.
Bionic bodies have been depicted in science fiction for decades. Now, researchers are making bionics the new frontier of medical science, by creating hi-tech devices to help people walk, see and hear again.
You only have to go to the movies to get an insight into the possibilities of bionics. The films Terminator, Ironman and Robocop all feature characters with artificial body parts.
One of the most well-known examples is Anakin Skywalker, of the Star Wars films. Skywalker was left for dead following a light sabre duel with Obi-Wan Kenobi. Having lost both legs and an arm and with his body badly burned, Skywalker was transformed into Darth Vader, with his distinctive black armour working as a life support system. Likewise, his son Luke Skywalker also received a bionic right hand after it was cut off in a light sabre duel.
Darth Vader and Luke Skywalker might be fictional characters from a galaxy far, far away, but creation of high-tech artificial body parts is already science fact here on Earth.
Research is underway in several key areas and although much has been achieved, bionics is still very much in its infancy. Scientists are striving to develop better controlled, lighter, smaller, more life-like and affordable bionic options. Here’s a rundown on the body parts you might be using in years to come.
Bionic limbs
The i-Limb™ has independently powered fingers that
can pick up everyday objects. (Image: Touch Bionics)
Artificial limbs have been around for hundreds of years. For instance, the Anglesey wooden leg was designed for the Marquis of Anglesey after he lost a leg in the Battle of Waterloo in 1815.
Such a replacement body part is known as a prosthesis. Prostheses can also be internal parts, such as artificial knees, hips or even false teeth.
But what’s different about the new generation of body parts is the way they combine several areas of technology and science such as electronics, biotechnology, hydraulics, computerisation, medicine and nanotechnology.
The term ‘bionics’ is relatively new, combining the prefix ‘bio’ – meaning life – with electronics. Bionic technologies create mechanical or electronic versions of living things or body parts.
The i-LIMB™, for instance, is an artificial hand with four independently powered fingers and a thumb. Each digit has a small motor and people using the artificial hand can grasp and pick things up, use scissors and even play cards. The i-LIMB™ attaches to the person’s arm stump and picks up small electrical signals from muscles in the arm to control movement of the digits.
A different type of bionic hand is the award-winning rehab glove designed in Sydney. Using a computer and artificial muscles, the glove allows people with paralysed or injured hands to move their hand or grasp objects.
Although artificial legs and knees have been around for some time, now they’re incorporating hydraulics, electronics and computer programming. These bionic legs enable better movement control by responding to the body and walking conditions. Other technology that uses electrical stimulation of the body’s existing muscles, enables paraplegics to walk again.
Bionic hearts
Artificial cardiac pacemakers that use electrical impulses to regulate a person’s heartbeat have been used for around 50 years. More recent is the development of artificial hearts; for now, these remain short-term treatments often used to buy time until a heart transplant becomes available.
The AbioCor artificial heart consists of a hydraulic pumping system which is totally implanted in the patient’s chest. An internal battery and electronics package are implanted in the patient’s abdomen to monitor and control the pumping of the heart. It is used for patients who have a life expectancy of less than 30 days and no other viable treatment options such as a heart transplant. The first recipient, Robert Tools, lived for 150 days with the artificial heart before dying in 2001. Another patient lived for more than 500 days with his artificial heart.
And more than 400 people worldwide have received the Australian-designed Vetrassist device. This device is attached to the left ventricle and helps the heart to pump blood to the body. However, the future of the Ventrassist technology is in doubt after the company went into liquidation in mid-2009.
Bionic ears
The cochlear implant, or bionic ear as it’s often called, is one of the big success stories of medical bionics. The technology was developed by Professor Graeme Clark and his team at the University of Melbourne in the 1960s.
Parts of the bionic ear
a. microphone; b. thin cord connecting microphone to speech processor; c. speech processor; d. transmitting coil; e. receiver/stimulator; f. electrode array; g. cochlea; h. auditory nerve.
(Image: © Department of Otolaryngology, University of Melbourne)
Deafness is often caused by damage to the minute hairs in the ear; these normally turn sound into tiny electrical signals that the cochlear nerve then sends to the brain. The bionic ear uses an external microphone that picks up sounds which are then sent via a processor to the implant. There, a receiver turns the sound signals into electrical impulses, which are sent via an electrode array to the brain.
wiring for sound Covers the development
of the cochlear implant and how it works. (Nova:
Science in the news, Australian Academy of Science)
Scientists are constantly improving the cochlear implant technology. The challenge now is to improve the clarity of hearing for recipients of the implant, particularly in places like crowded rooms or when listening to music.
Bionic eyes
The Australian government has allocated $50 million to fast track research into the bionic eye. Developing a bionic eye is a challenging task; Australian scientists are meeting the challenge from a couple of different angles (Box 1: Focusing on bionic eyes).
There are three main types of bionic eye being developed around the world. These usually involve one of the following approaches:
- Electrical stimulation of the retina, where images from an external camera are transmitted to a microchip on the retina wall or the eyeball, with electrodes stimulating the optic nerve to send signals to the brain.
- ‘Mini telescopes’ implanted into the eye that magnify images onto the retina. Such implants are being developed for people suffering from macular degeneration; and
- Bypassing the eye, where the image information collected by a tiny external camera is sent to a processor then to electrodes implanted in the brain.
Although early trials have proved promising, so far there is very limited resolution or detail in what a person can see using such devices. But it’s still early days and the technology is developing rapidly.
Brain bionics
One of the most challenging areas of bionics is to allow a person to control a bionic device by using their brain – in effect, turning their thoughts into actions.
Already scientists are developing implanted neural interfaces – nerve interfaces or brain implants – to help achieve this. One team has reported being able to assist a quadriplegic check emails and play video games using a computer chip implanted on the surface of his brain. Elsewhere brain-computer interfaces are being developed that let people move their wheelchairs around objects using electrical signals from their brain.
In other developments, researchers are looking at implanting electrodes in a person’s brain – known as deep brain stimulation or a ‘brain pacemaker’ – to treat Alzheimer’s disease, depression, epilepsy or Parkinson’s disease.
Nanobionics
An animation explaining Australian research into
nanoscale electromaterials, including nanobionic implants.
(Australian Research Council Centre of Excellence for
Electromaterials Science)
Incredible as it might seem, a new area of bionics is also being developed using nanotechnology. Known as nanobionics, it involves the use of tiny electrical circuits and materials made at the atomic or molecular level.
At such a scale, tissues of the body can be targeted more effectively and bionic technologies can be miniaturised. For instance, Australian researchers are looking at using minute carbon nanotubes to help implants connect better with living tissues and nerves. The technology may contribute to the next generation of bionic ears: nanoelectrodes could improve the implant’s connection with nerves compared to the current platinum electrodes.
Similarly, nanobionics is being embraced to help repair spinal cord injuries – or other damaged nerves. Implanted nanoscale materials like carbon nanotubes can be used to encourage regrowth of damaged nerves and at the same time guide the direction of their growth. While the safety of carbon nanotubes is yet to be confirmed, Australian scientists are trialling implants using intelligent plastics which – with electric stimulation – can deliver molecules that encourage nerve regrowth.
The emerging field of medical bionics
In 2007 Professor Graeme Clark pointed out that technology is again heralding a new era of medicine. He and others use the term ‘medical bionics’ to refer to the use of technology to restore body functions. That term, and others such as nanobionics are still so new many people haven’t heard of them.
Bionics might be a relatively new field, but chances are even Luke Skywalker would be impressed by what’s already been achieved as part of the bionic revolution.
Box
1. Focusing on bionic eyes
Credits
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Posted May
2010, edited August 2012.