The Computer-Aided Design and Manufacturing (CAD/CAM) Laboratory is where research and development on Squirt Shape, an additive fabrication technology for the production of prostheses and orthoses, takes place. The space consists of a Partner I computer-numerically controlled (CNC) milling machine with four axes of simultaneously controlled motion.  The four axes are the x, y, z, and a rotary axis. The CNC mill serves as the backbone of the alpha-prototype Squirt Shape system. We also have a beta-prototype of Squirt Shape that uses a water-cooling method to speed-up socket construction (see figure 1).

Figure 1: The Squirt Shape method of socket production. Thin layers of melted plastic are deposited using a motion-guided extruder.  Layers are stacked one upon another and thermally bond together to create the prosthetic socket.

The CAD/CAM Lab is also equipped with a Provel d1 mechanical digitizer and Shapemaker software (see Figure 2). The mechanical digitizer measures the dimensions of a cast or mold of the residual limb and transfers the data to the Shapemaker software, which creates a three-dimensional computer model. This computer model of the residual limb is modified digitally to relieve pressure in sensitive areas and apply pressure in tolerant areas. Once modification is finished, a data file with positional instructions is sent to Squirt Shape for fabrication.

In addition, the CAD/CAM resources are utilized in other projects like gait studies of amputees where multiple prostheses per subject are needed. CAD/CAM enables easy iterative modifications to socket shape and rapid fabrication of prosthetic sockets. Such procedures would be very time and labor consuming if performed manually.