COMBINING ENGINEERING AND MEDICAL KNOWLEDGE FOR MANUFACTURING MEDICAL DEVICES USING CAD/CAE/CAM TECHNIQUES
Prosthetic medical devices are very important for people’s health and quality of life. Most of them are still manufactured using a handcraft approach, even high-tech materials and equipment are used in the process. Thus, the flexibility and repeatability of the manufacturing process are very low, which leads to high-costs, making the availability of these devices very cost-sensitive.
In order to overcome this drawback, this paper proposed an integrated approach of designing and manufacturing the medical devices using engineering computer aided design methods and training the manufacturing engineers with basic medical knowledge related with the use of these devices.
New engineering technologies, such as 3D scanning, together with the new generation of CNC machine-tools offer engineers new instruments for making the manufacturing process of complex parts, with complex shapes very flexible. Instead of losing a great amount of time building a very complex 3D model of prosthesis, an existing one may be scanned (or a clay replica can be crafted rapidly and scanned) in order to obtain very quickly the 3D model, which afterwards can be edited and personalized. Normally, such a device contains complex surfaces, which have to be manufactured on different machines, using different operations (milling and turning operations). The modern CNC machines are equipped with more than one working unit and consequently, milling and turning can be performed on the same machine. Also, the new CAM programs facilitate the use of six degree of freedom industrial robots for manufacturing complex parts.
However, the problem of processing complex shapes in a flexible and repeatable way, with low cost is not the only problem in manufacturing medical prosthesis. Cranial implants or orthopedic prosthesis, for both of them, the fact that they have to work in close contact with live tissues raise a lot of problems, one of the most important being the bio-compatibility. Thus, the manufacturing engineer has to be able to select bio-compatible materials as workpieces and to test their bio-compatibility in every stage of the manufacturing process. Also, the processing operations have to be chosen in order to fulfill the two main objectives: obtaining the prosthesis with the prescribed shape and accuracy and preserving its biocompatibility.
The authors of the paper proposed a special course of “CAD/CAE/CAM approaches in manufacturing prosthetic devices”, which will be proposed to be introduced in the curricula of a manufacturing master programme at “Lucian Blaga” University of Sibiu, Romania. The paper presents the main methods of using modern CAD/CAE/CAM techniques in the process of manufacturing prosthetic devices, how will these methods presented and taught to the master students and how the engineering knowledge will be completed with medical knowledge in order to train a specialist in this important field.