A Form Of Therapy

appeared in »design report« 6/2009 / pages 32-34

Prostheses and orthoses are, just as all medical products, perceived and accepted or rejected by a very complex environment. A successful, technical medical product has to satisfy physicians who are issuing treatment or are scientifically active, practising orthopaedists and prosthetists, patients, their relatives, insurance providers, legislators, accompanying therapists, construction engineers, calculating businessmen and sometimes also juries of design competitions. With so many potential recipients, an innovative medical product can only be developed in an interdisciplinary way.

Although in medical engineering a systematically embedded innovation is a necessary condition for success, each innovation is confronted by a system which is altogether slow, contrary to the consumer market, and justifiably so. Who wants to test a quick-fire solution of medical technology on his own body?

Proven module principle

Orthopaedic technicians usually adjust ortheses and prostheses to patients’ limbs. The industrial prefabrication of those once manually manufactured products has been constantly growing. The systematization of pre-produced prosthesis components introduced by the entrepreneur, Otto Bock, after the Second Wold War is still valid, even though construction and design techniques have been refined and further developed. The modular tube-skeletal system (shaft, knee joint, tube, feet) is state-of-the-art and as a system has successfully remained unaffected by numerous innovations such as digitalization for example, or by material alterations (from steel into aluminium into plastic, and finally into carbon fibre).

Currently, the question which has arisen is whether future innovation will happen within the already existing tube-skeletal system or if a completely new system will come into being. The prototype study of a lower leg prosthesis in the exoskeletal frame, which was presented in 1996, illustrates this search for a new design principle.

Orthosis gets sportier

Contrary to prosthetics, new materials and their respective combinations in orthotics have promptly resulted in novel constructions, since an orthosis is not subject to any comprehensive system concept. The extremely diverse choice of materials was developed from wood, leather, steel and stitched textiles into aluminium and plastic, and finally into fibre-reinforced materials, multi-component injection mouldings and high performance textile combinations, which these days are usually bound. Occasionally, age-old splint design principles can still be found in combinations with high-tech materials. In woodwork, this phenomenon would come close to a wedge connection, whose wedge would be made of carbon fibres.

Altogether, the look and feel of ortheses demonstrates quality improvement and a growing resemblance to functional clothing and sports products. In turn, they are subject to “medicalisation” due to an interactive transfer between medical technology and other disciplines.

Interface problems today and tomorrow

An interface between an orthosis or prosthesis and a limb is, and will be critical for the success of orthotic or prosthetic devices as well as for the wearer’s comfort. Great craftsmanship is necessary to produce a prosthesis socket with optimal residual limb bedding, or a paralysis orthosis for a growing child or even an anatomic foot-bed for diabetics, who might have very sensitive skin properties. The auto-adaptive back orthosis “Lumbo TriStep,” whose auto-adaptive support elements adjust themselves to the patient’s body shape for a perfect fit, shows a new way here. “Lumbo TriStep” was developed by orthopaedic technicians, engineers and doctors from the Otto Bock Company together with external designers.

Again, new technologies draw our attention to the interface between prosthesis and its user, this time in terms of steering and information transfer. The surgeon, Ferdinand Sauerbruch (1875-1951), can be considered a precursor of an actively controlled prosthesis. Its innovative operating method enabled the joining of a prosthetic hand with the remaining muscles of an arm in such a way that an actively guided closing of the hand was made possible. Later, myo-electrically controlled solutions were developed. They use pattern recognition systems to classify input motions: a sensor perceives skin tension changes caused by muscle activity and uses them to control movements.

This interface is noticeably moving into the interior of the body. Today’s vision is a thought-controlled prosthetic device. An extended usage of remaining nerve endings or even brain implants is the major focus of research in this case. A successful application of these technologies may also play an avant-garde role in non medical-technical contexts. Access to the brain always spurs fantasies of control obsessed and performance-fixated individuals whose major aim is not healing or alleviation of pain and disability but artificial enhancement of human capacities.

Design at its purest

In medical technology, not only the designer but also the paying customer is confronted by the question of whether the designer should act as a maverick and make existing creations simply beautiful, or whether beautiful products should be the final result of interdisciplinary cooperation. Is he able to provide only product designs or can he (co-)design and actively participate in the implementation phase, which is usually characterised by surprises? All the products included here originated from the afore-mentioned concept of cooperation.

If the principle question at the beginning of a project is of a rather closed nature, namely; “Please create a splint design and shell apparatus for a paralysed patient,” possible results and innovation potentials will already be strongly reduced in the preparatory stage. On the other hand, open questions such as “What kind of a wearable support system can we offer a paralysed person?” inspire innovative thinking.

Typically, design and construction in prosthetics and orthotics work without a possibility to hide construction: but in the face of permanent pressure, it is difficult to offer functionally complex, compact, cost-effective and highly efficient solutions. Little place is left for additional ornamentations or concealed manoeuvres, such as those we know from the consumer market. For a designer, it is a situation which can be compared to open heart surgery, because he usually works with visible structures. The hiding of the structure resembles here an escape which can lead to additional financial or weight expense.

Respect for a patient

A designer moderates a product’s encounter with its users and supports its ability to function on and with a person. Since industrially pre-produced products are internationally employed, it is becoming increasingly important to communicate properties of a product and its operability non-verbally and through design. An industrially produced medical device will not only be discussed in dozens of different languages, it will also be confronted with diverse mentalities and therapeutic traditions. The more self-explanatory, readable and comprehensible manner in which an innovative device starts its way into the world, the bigger its chance of success.

Medical devices can neither change the clinical picture of disease nor the social image, yet a fascinating design can boost a patient’s self-confidence and improve his perception. Contrary to a purely indicative construct, a product which is proportionate, ergonomic and suitable for everyday use respectfully treats a patient as a complete human being.

Design in medicine is innovation design

Design, in the sense of beautifying and embellishing, can have a thoroughly negative connotation in the medical-technical environment. An ostensibly styled medical device can arouse distrust of a patient as well as of an insurance provider. Beautiful products are not principally objectionable, yet their beauty is still far from being a reason enough for a health insurance company to pay for them. Contrary to the consumer market, the medical technology market neither highlights nor rewards artificial emotionality as a purchase criterion.

A designer in medical technology quickly reminds himself of a sometimes forgotten concern of design, namely increasing the usefulness and readability of a product for all parties concerned. The faster the designer develops ideas which support a better healing process, alleviation of pain or user-friendly device operation and application, the earlier he will integrate himself into the world of medical technologies, and be able to co-design a fascinating future. Innovations can be created by all participants of an interdisciplinary development process, and, as has been proven, by designers.