Lockable elements secure form

Researchers have developed an improved design of spinal brace, using interlocking plastic components. Injection moulded elements can be clipped together and moved relative to each other during construction – then locked into position by activating an adhesive. This can be done in a few seconds – a huge improvement on the current slow process of fitting a back brace. FlexNLock consists of large numbers of three-lobed, injection moulded elements, each with either balls or sockets at their extremities, facing perpendicular to the plane of each element. The elements, which form two layers facing each other, may be pressed together. This forms ‘sheets’ which can then be compliantly moulded to the shape of the person – if they are to be used as a spinal brace – or to a former if they are to be used for some other purpose. Each ball and socket joint contains an adhesive that remains liquid until activated either by heat or a flash of ultraviolet light, upon which the adhesive is cured and the whole construction locks into place. The idea is the brainchild of Karnik Tarverdi, and has been developed in conjunction with the Wolfson Centre for Materials Processing, the Institute for Bioengineering at Brunel University and the Centre for Disability Sciences at the Royal National Orthopaedic Hospital in Stanmore. Spinal braces are used to support or immobilise the spine following surgery or trauma, and for the treatment of spinal deformities. The brace applies force to the spine, preventing the curve from increasing. The current technology is to take a cast of the patient, from which a plaster mould is made. A large sheet of polyethylene is drape moulded onto the mould and then trimmed to the patient, after which, fasteners or straps are added. The brace is worn like a jacket. The fabrication and fitting is labour-intensive with a delay of several weeks between an initial fitting and the patient being given a finished brace. Over this time, the spinal deformity may continue to progress. A standard brace costs £300-500 and must be fitted by an experienced person. The new technology, on the other hand, can be formed and locked into shape in a matter of seconds. It inherently incorporates holes, easing perspiration and heat loss from the individual. According to Dr Tarverdi, the technology “cannot compete with plaster of Paris” as a conventional splint. However, he claims that it competes well with other technologies used to fabricate lockable, articulated structures that require perhaps hundreds of individual modules to be screw-clamped. The innovation was seen at the recent Medical Innovation Forum in London, organised by Enterprise Events. The prototype is made from polycarbonate, but braces could be made from almost any material. A patent has been applied for. FlexNlock Enterprise Events Pointers * The injection-moulded elements of the new brace are low cost and can be clipped together in seconds * Once formed to shape, the construction may be locked by applying heat or ultraviolet light – according to the type of adhesive used in the joints.