The final provision of an artificial hand in Heidelberg

In the last issue of Barrierefrei we introduced you to Stephan M. from Flensburg who lost most of his hand in an accident with electricity. We, from Barrierefrei, accompanied Stephan through the test version of his first myoelectric artificial hand at the firm seat of Touch Bionics in Heidelberg in February of this year and we reported on it.

The British concern is one of the leading producers of artificial limb technology worldwide and has set itself the goal of ensuring the best possible provision for people with limbs missing from the upper extremities. The myoelectric hand, partial artificial hands, as well as realistic silicon passive limbs which match in with the wearer’s natural look, belong to their portfolio. Touch Bionics was taken over by the Icelandic firm Össur, who belong to the leading producers in the field of artificial limbs worldwide, in May 2016.

After documentation had been submitted to the authorities, proving how many and, more importantly, how big the advantages of having an artificial hand would be for Stephan in his everyday life, the definite grant for the provision of a partial “I-digit” hand system, made by Touch Bionics ,was permitted.

The previous test model fitted perfectly so that only minor adjustments had to be made to the final product. In this case, a zip was put in further up, making it easier for Stephan to put on and take off.

A new silicon shaft was made with the help of a previously made plaster of Paris cast, this time even in the colour Stephan wanted: Blue. After that the shaft was cast using fibreglass (and a decoration stocking was included in the cast for the carbon optic effect), thumb and index finger were positioned and then cast again with fibreglass to strengthen it. In this way the shaft is an ideal and necessary basis for the strengthening of the fingers (technique) and for the accumulator packs. It’s only screwed together with the silicon lining, making it easier to reach the technical elements for maintenance or repairs if necessary. While Stephan’s technicians from the medical supply firm of Schütt & Jahn from Flensburg (within the framework of their certification) were busy with the making of the artificial hand, he was practicing the technology with his therapist using the test model.

The artificial myoelectric partial hand is steered by complicated technology. Electrodes, integrated in the shaft, give out signals to open and close the fingers. These electrodes work over the surface of the skin to take away the electricity which occurs when muscles are flexed. The electricity lies within the myovolt area, thus the name myoelectric. These muscle signals are strengthened by the control electronics. Ideally, there are two electrodes: One to open and another to close the hand or finger. The control electronics send out the corresponding signals to the individual finger motors. Now the patient is able to control different grip movements using different muscle signals which have been programmed in the control electronics. There is also the possibility to link the hand to his smartphone using Bluetooth, and so choose gestures or gripping movements. Should this kind of setting be too complicated, there are also extra, so called, “Grip Chips”. Grips needed for daily use are programmed on these “Chips”.

An example: An office worker needs various finger positions when typing on a keyboard, holding the phone and using the mouse. The three different grip techniques can be programmed onto the “Grip Chip”. This chip is placed in the office. The three different gripping techniques are passed over to the artificial hand if the patient places his open hand on the chip. A permanent contact to the smartphone is no longer necessary.

On completion of the new artificial hand Stephan proved its everyday use on site. He went shopping in a supermarket with his therapist. They made sure that Stephan didn’t fall into his old movement pattern, from the time before the artificial hand. After that they cooked, so successfully concluding the test and training.

For Stephan, the new hand means not only pleasure and relief in everyday life but also, of course, quite a big adjustment. After all, he’s managed his life without thumb and index finger for over twenty years and now he must “retrain” the usage. “Time and patience are needed for that. But it will be a small help with my hobby – snooker”, tells Stephan. Specially for that, rubber has been placed on the inside of the artificial hand between the index finger and the thumb ensuring safe support and stopping unnecessary damage to the cue.

A provision such as this usually takes between two and four weeks. The cost factor for Stephan’s artificial hand was around 55,000 €, which (in this case) was paid for by the BG. It’s important for the provision of an artificial or partial hand system made by Touch Bionics that the patient is capable of sending myosignals and so be able to control the artificial hand.

Further information & contact:

Touch Bionics GmbH

Langer Anger 3
69115 Heidelberg
Tel.: 06221. 357 9060
Fax: 06221. 585 9931