Due to the increasing number of eye, brain and central nerve system tumor patients, radio oncology has become more and more important in the past years. Accordingly, various devices that are needed for a successful therapy have to be optimized or newly developed. Especially high precision masks for stereo-tactic radiology suffer from several weaknesses. Correspondingly, the inconvenient manufacturing, the lack of comfort for the patient and questionable fixation performance shall be improved by the development of a 3D printed personal patient fixation device.
This project portrays the development of an individually, for the patient tailor designed 3D printed mask. It presents the relevant medical and technical considerations and the methodology for the construction of the device. Based on MRI images a virtual 3D model of the patient's head was built. Additional design of the facial 3D model led to a virtual fixation device in form of a mask. In addition, the virtual model was additive manufactured with the material ABS via fused deposition modeling (3D printing). Further evaluation of the device in terms of fixation performance and ergonomics enabled a comparison of the 3D printed model and the current used conventional mask. The evaluation was done with a FEM simulation and the measurement of pressure between the mask and the face. Furthermore, the accuracy performance of the 3D printer was investigated by a comparison of the geometrical target- and actual value of the 3D printed and conventional mask. The thesis also includes a costs calculation for the newly developed product.
The overall findings of this thesis show that the first prototype clearly outperforms the conventional device in terms of ergonomics, whereas the even more important fixation performance still has to be optimized for the future prototypes. The results of the geometrical target- and actual value comparison revealed a sufficiently high accuracy of the 3D printer. The costs calculation for the new device shows that the required machine usage time for one device dominates the the overall costs. Therefore, the printing speed has to increase in order to manufacture cost-efficient products.
Without doubt one can summarize that modern additive manufacturing technologies have the potential to replace conventional immobilization devices in the future. However, regarding costs and fixation performance there is still space for improvement before the product can be placed on the market.