PRELIMINARY EXPERIENCE WITH MEDICAL APPLICATIONS OF RAPID PROTOTYPINGBY SELECTIVE LASER SINTERING

Rapid prototyping techniques, originally developed for building compon ents from computer aided designs in the motor industry, are now being applied in medicine to build models of human anatomy from high resolut ion multiplanar imaging data such a computed tomography (CT). The esta blished technique of sterolithography and the more recent selective la ser sintering (SLS), both build up an object layer by layer. Models ha ve applications in surgical planning, for the design of customised imp lants and for training. Preliminary experience of using the SLS techni ques for medical applications is described, addressing questions regar ding image processing, data transfer and manufacture. Pilot models, bu ilt from nylon, included two skulls (a child with craniosynostosis and an adult hypertelorism) and a normal femur which was modelled for use in a bioengineering test of an artificial hip. The dimensions of the models were found to be in good agreement with the CT data from which they were built-for the child's skull the difference between the model and the CT data was less than 1.0+/-.05 mm in each direction. Our exp erience showed that, with care, a combination of existing software pac kages may be used for data conversion. Ideally, image data of high spa tial resolution should be used. The pilot models generated sufficient clinical interest for the technique to be pursued in the orthopaedic f ield. (C) 1997 Elsevier Science Ltd for IPEMB.