Using haptic modelling for spinal implant design

Abstract

The link from medical scan images through data manipulation to additive manufacturing is well established. Various types of software are used to deliver the required .STL file(s). Often, the data manipulation will require the generation of new shapes around existing geometry, e.g. an implant that will replace missing bone tissue. This paper reports exploratory work undertaken to assess the feasibility of using haptic modelling and "virtual sculpting" software to generate novel designs of vertebrae implants for correction of spinal curvature. .STL data of several vertebrae, originating from CT scans, was imported into the Freeform system from SensAble technologies. It was used to create immutable "bucks" around which the user "sculpted" three-dimensional implant geometries. It must be noted that the designs have not been medically assessed and were for demonstration purposes only. However, the process route followed did prove to be feasible and offered some particular advantages, e.g. a precise fit between the implant and the vertebra and the possibility of enabling the direct intervention of medics in the implant design process.