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Expertise from Vienna: bionic reconstruction replaces useless hands

(Vienna, 25 February 2015) The leading medical journal, "The Lancet", has just published a study by Oskar Aszmann. In this study, Aszmann describes the bionic reconstruction technique he has developed at the MedUni Vienna. Complex neuromuscular procedures are performed to create a biotechnology interface that gives patients mechatronic hand functions. Patients can subsequently get on with their lives with two hands again.

The brachial plexus, the bundle of nerves running down the arm, controls human arm and hand function and is supplied by five "roots" from the spinal cord. Serious accidents can tear these roots out of the spinal cord, destroying the hand's function and sensation. In most cases, conventional surgical techniques are unable to help victims of such trauma.

 

The bionic reconstruction method on three patients described in the Lancet study, however, changes this. Oskar Aszmann, Head of the Christian Doppler Laboratory for the Restoration of Limb Functions at the MedUni Vienna's Department of Plastic and Reconstructive Surgery, explains what the method involves: "Bionic reconstruction is a holistic concept that covers more than just surgical technique. It involves complex neuromuscular activities that make an interactive interface possible between humans and machines. To begin with, a precise exploration needs to be carried out of the global hand/arm function and the remaining nerve branches. These are then biopsied during a surgical procedure and their function checked. If they respond positively, a piece of muscle is removed from the thigh and transplanted into the forearm. The muscle acts as a signal amplifier for the remaining nerves." Aszmann continues: "Muscle contraction generates electrical signals of adequate strength. These myosignals are used to control the new, mechatronic hand."

 

But before the new hand is attached, the patient first learns how to use the prosthesis via an electronic interface. This is important, as the patient's brain will have forgotten how to use the hand since in some cases it may already have been non-functioning for a number of years. Once this technological neuro-rehabilitation is complete, the non-functioning hand is amputated and ultimately replaced with the hand prosthesis. The patient is therefore given back a voluntarily controllable, functioning hand.

Tremendous additional benefit for patients
"For the patients, it is always a tremendous additional benefit to continue their lives with two hands. Patients are able to get back to work, and their relationships and private lives improve considerably." Another important point is the subject of pain. "Patients often experience severe phantom pain. This pain disappears with the bionic reconstructions, since the phantom is being replaced by the restored functionality of the hand."

 

Vienna leads the world
Aszmann's bionic reconstruction concept was first tried out in 2009. Since then, Aszmann and his team - the MedUni Vienna is the world's only facility to use this technology - have been able to restore the physical integrity of numerous patients and help them to enjoy a new quality of life and vitality.

 

Bionic reconstruction is not body enhancement
Aszmann is keen to point out that bionic reconstruction is in no way a form of body enhancement. "We are seeking to restore defects, not make healthy people even better." Aszmann therefore has reservations about other types of bionic technology: In a further study, recently published in the specialist journal "Science Translational Medicine", Aszmann and Dario Farina from the University of Göttingen are critical of the benefits of implanted electrodes to control hand prostheses. The two authors conclude that the majority of the technologies currently being used are causing patients much more harm than good, and that they are of dubious ethical merit.

Service: Lancet
„Bionic reconstruction to restore hand function after brachial plexus injury: a case series of three patients Bionic reconstruction to restore hand function after brachial plexus injury: a case series of three patients.“

Oskar C Aszmann, Aidan D Roche, Stefan Salminger, Tatjana Paternostro-Sluga, Malvina Herceg, Agnes Sturma, Christian Hofer, Dario Farina. February 25, 2015. dx.doi.org/10.1016/S0140-6736(14)61776-1.

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Video - Interview with Oskar Aszmann