1. The use of Rapid Prototyping to assist medical applications I. Gibson, L.K. Cheung, S.P. Chow, W.L. Cheung, S.L. Beh, M. Savalani, S.H. Lee

2. Outline of talk  Discuss the general process of medical RP  Consider a range of applications in the medical field  Discuss the impact on RP technology development  Conclude

3. Medical modeling  Also referred to as biomodeling or stereomodeling  Construction of patient data in a physical form  Integration of medical reverse engineering with CADCAM

4. Generalised procedure for creating medical models.STL File Medical Software (e.g. Mimics, 3D Doctor) RP System Finished RP Model Post Processing (E.g. Cleaning, Curing, removing supports) Medical Imaging Data Capture (e.g. CT data, 3D ultrasound) CT / MRI Scan CAD (Optional)

5. Medical modeling process  CT/MRI data most common methods used –Resolution not high –Dosage levels and processing time/cost  Not many dedicated software conversion packages  Few medical modeling users – why?

6. Oral and maxillofacial surgery

7.  Many such cases now exist  Starting to become routine for complex cases  Reductions in surgical times  Eases planning  Improves cosmetic appearance

8. Distraction osteogenesis

9.  Mainly used for planning and rehearsal  Fixation sites difficult to locate  Model used as template for customising distraction device  Different treatments can be explored  Procedures carried out over long periods of many months

10. Artificial finger joint design

11.  RP used as a backup process  Typical product development process  Models made to illustrate design features and alternatives  Also used to design and test surgical implements and procedures  Helpful in integrating anatomical features with engineering designs

12. Forensic pathology

13.  Numerous potential applications  Making models prevents destruction of evidence  Models provide opportunities to test hypotheses  Models can be used in court to demonstrate hypotheses

14. Tissue engineering

15.  Bony tissues are 3D constructions  Cells require a template or scaffold to provide this structure  RP techniques ideal for constructing templates  However, templates should also be heterogeneous and provide capacity for multiple materials

16. Issues concerning RP technology choice  Speed – RP still slow for many applications  Cost – every case is a custom case  Accuracy – not a significant problem for most medical cases  Materials – must withstand harsh handling  Ease of use – new skills required

17. Conclusions  RP ideal for numerous medical applications  However, specification of RP technology is different from conventional applications for RP  Many medical applications on the cutting edge