Our team of specialists at the University of Michigan Orthotics and Prosthetics Center utilize a CAD/CAM (computer-aided design/computer-aided manufacturing) system to design and fabricate orthotic and prosthetic devices. The system includes:

  • Digitizer - which traces a shape and converts it into digital information.
  • Workstation - with TracerCad software used to modify the three-dimensional shape.
  • Carver - carves the shape with a high speed cutter.

The CAD/CAM system speeds the process of casting and modifying many orthotic and prosthetic devices. The design and manufacturing procedure is more efficient, and the turn around time is reduced. 

An example of increasing our productivity is comparing the usual procedure of transporting, filling, and building custom body jackets (TLSO) versus utilizing the CAD/CAM system.  Previously the body mold would be given to technicians who would close and fill it with plaster. These castings would sometimes weigh over 250 lbs. The mold would then be stripped and modified. Using CAD/CAM we now digitize the mold or create the shape from measurements on the CAD/CAM system and electronically send the file to the manufacturing location.  A model is carved out of a lightweight foam, which is then used to fabricate the TLSO.

Prosthetically, patients can be provided with test sockets very quickly and efficiently.  The mold taken, digitized and electronically modified and then sent to the carver. The carver cuts the socket design from foam block using a large drill bit. Once carved, the model is given to a technician for fabrication. The patient's 3-D image is stored in an electronic file for future reference. The file can be easily retrieved and modified in the future to provide patients with the best possible fit over time. 

Modification of the 3-D shape using the CAD/CAM system is done with the click of a mouse versus the mixing and applying of plaster and then waiting for the plaster to set. Measurements are better quantified (i.e. the computer can calculate residual limb volumes in "cc's") which can be useful in research or justifying the need for a replacement due to volume changes. 

This CAD/CAM technology allows O&P clinicians a state of the art tool to address patients orthotic and prosthetic needs with a greater degree of precision.