- Will give amputees a genuine sense of touch
- Attached directly to the nervous system via electrodes
- ‘We hope one day the user will just forget it’s there’ Dr Silvestro Micera
A bionic hand which allows the recipient to feel ‘lifelike’ sensations is to be transplanted on to a patient’s arm for the first time.
Until now, artificial limbs have been able to pick up brain signals destined for the absent hand and translate them into movements, but they could not give sensory feedback.
The new hand, which is attached directly to the nervous system via electrodes clipped on to two of the arm’s main nerves, aims to restore a sense of touch in amputees.
Scientists hope the new bionic hand will prove to be a breakthrough in the development of artificial limbs
The electrodes will allow the recipient to control the hand using just their thoughts – and will also send signals back to the brain. Scientists hope the breakthrough will pave the way for a new generation of artificial limbs that more closely imitate real body parts by providing feeling and increased dexterity.
Studies have shown that up to half of hand amputees do not use their artificial limb because they are not comfortable with how it appears or functions.
Dr Silvestro Micera, of the Swiss-based Ecole Polytechnique Federale de Lausanne, who helped develop the limb’s interface, said: ‘This is real hope for amputees. It will be the first prosthetic that will provide real-time sensory feedback for grasping.
‘It is clear that the more sensory feeling an amputee has, the more likely they will get full acceptance of that limb. We hope that one day it will be embedded in the arm and the user will just forget it is there.’
In 2009 an earlier, fixed model of the hand was temporarily attached to a patient’s nervous system via electrodes.
He was able to wiggle the fingers of the robotic hand, make a fist and hold objects, and said he could feel needles being jabbed into the palm.
The new model, which will be fully attached to the arm, can deliver sensory feedback from all the fingertips, as well as the thumb, palm and wrist.
The team plans to transplant it into an anonymous patient later this year.
Dr Micera, who was attending the American Association for the Advancement of Science’s conference in Boston, said: ‘The idea would be that it could deliver two or more sensations at one time.
‘You could have a pinch and receive information from three fingers, or feel movement in the hand and wrist.
‘We have refined the interface, so we hope to see much more detailed movement and control of the hand. It is intended to be as lifelike as possible.’
Speaking at the American Association for the Advancement of Science (AAAS) annual conference in Boston, he said the team plans to transplant the new hand into an anonymous patient in Rome later this year. The only details known about the recipient is that they are in their 20s and have lost the lower part of their arm following an accident.
The only details known of the first bionic hand recipient is that they are in the their 20s and lost the lower part of their arm following an accident
It will be worn for a month to see how the patient adapts, but if all goes well, Dr Micera hopes to have a fully-working model ready for testing within two years.
Scientists from the EPFL also offered fresh hope for patients paralysed as a result of back injuries.
Last year, a team led by Gregoire Courtine enabled rats with severed spines to run again, using a cocktail of drugs and electrical impulses to ‘regrow’ nerves linking the spinal cord to the brain. After two weeks, the animals were not only able to walk, but climb stairs and run.
He has since repeated the study in rats with bruised spines, which more closely resembles human trauma patients, and after a few weeks they could walk with no assistance. He now believes that the technique could help people who have been immobile for up to two years.
Although full human trials are still a few years off, he plans to attempt electrical stimulation on five patients who have limited leg movement in the coming months.
‘We know that spinal cord stimulation is safe, we know that training is good, so we want to start the first trial in people who can move their legs but cannot walk independently. So we will implant five patients, we have a new technology which allows us to stimulate the spinal cord of humans just like we do in the rats.’
Once they have refined the technique, they hope to fully rehabilitate patients with moderately damaged spines, while others would regain some movement.
‘We already have preliminary data from the rats with these clinically relevant lesions is that a number of them would recover at the end of the training and could walk without any help. It depends on the severity of the damage,’ he said.
‘But if you talk to the patient and you tell them at least you could use it at home to cook, to watch TV and have normal activity, they say their life would be so different. So it is less ambitious, but we are talking about improving the quality of life, allowing people to stand and take a few steps at home with a walker.’
Read more: Source