Rapid prototyping is the technology of automatic freeform fabrication of physical objects from virtual CAD (computer aided design) models. For medical objects the models may be created using data from CT, MR or rotational angiography. We descriobe the case of a 83-year-old woman with essential bilateral hearing impairment as the effect of chronic otitis media. An individually fitted hearing aid was produced for the patient using stereolithography technology and vacuum casting based on data obtained during ear CT. Rapid prototyping may help in manufacturing individually adjusted biomedical prostheses, reducing the time of device production and improving its fitting.

Abstract. Computed tomography and rapid prototyping techniques can be used to construct and fabricate large size bone models for orthopaedics. Rapid Prototyping technology enables the fabrication of a true-to-scale bone joint model based on 3D virtual models, generated by segmenting patients' CT images. The model can be used to plan, to simulate, to assist prosthesis implantation for difficult cases of THR (Total Hip Replacements). The main restriction of implementing such models into medical practice is high cost of their production. Physical models of pelvic bones, were constructed on the basis of data collected during standard CT examinations. A method of development of a large-size model while fulfilling the requirement for reducing the price of model fabrication in the article was presented. The method can be used for fabrication the models with 3DP technique. This paper also discusses the issue of production costs when utilizing other RP techniques as well as their usefulness in practice.

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Abstract. This article presents reconstruction methods applied to a (geometrically and physically) complex structural object with the use of RP and RT techniques. The methods are innovative due to their hybrid -multi-model and multi-material -approach to reconstruction, as well as the application of multiple technologies. An experimental analysis was conducted to verify the feasibility of rapid prototyping (RP) techniques in the reconstruction of complex internal structures using materials of diverse properties. Some RP techniques offer the possibility of discriminating between diverse objects through the use of different colours. Such models are well-suited for diagnostic purposes, for better visualisation of complex clinical problems, pathological alterations, etc. Nevertheless, they fail to fully reflect physical and mechanical properties of objects, which renders them useful in experimental analysis only to a limited extent. Their basic drawback is that they merely reflect geometrical features of the examined object. The methods discussed in the present article enable modelling multi-object structures in a single process based on the PolyJet Matrix technology and materials of different physical properties by means of a hybrid method. The article also describes the process of modelling complex anatomical structures of soft tissues and bones using models of the maxilla and the mandible as examples. The study is based on data acquired through standard computed tomography (CT). In addition, the article addresses selected aspects of CT acquisition, generation of numerical models composed of several anatomical structures (objects) and fabricating physical multi-object models.Key words: medical modelling, rapid prototyping, computed tomography (CT), experimental tests. tual models (3D numerical models) can be developed with the use of CT or MRI data. They can be useful in designing and fabricating physical models of real tissues by means of rapid prototyping techniques [3,4]. 3D models generated by the authors of the present study are shown in Fig. 2; they are based on anatomical structures presented in Fig.1. RP methods enable us to create physical models for medical purposes [5] such as: Methods of reconstructing complex multi-structural anatomical objects with RP techniques• maxillofacial and dental surgeries, • orthopaedic and spinal surgeries, • oncology and reconstruction surgeries, • customised joint replacement prosthesis, • patient-specific instrumentation (orthoses), • implant design, testing and validation.

Polymer insert is one of the components of a knee joint endoprosthesis, allowing patients to sustain their mobility. They are mostly made of ultra-high molecular weight polyethylene (UHMWPE) that is not without flaws. Inserts can be manufactured by machining (substractive techniques) or by the use of rapid prototyping techniques (additive manufacturing). In order to increase their strength, is increasingly being considered replacing UHMWPE with polyether ether ketone (PEEK). This material has been analyzed in this work due to the growing interest in using this material for the production of implants. This study contains a comparative analysis of two inserts made using two different methods. Its aim is to verify the effect of the manufacturing technique on material uniformity.