Development of a Tensegrity Based 3D Printable Transradial Canine Prosthetic

Total amputation is the traditional treatment for canines that require forelimb amputation; however, it has negative impacts on gait, weight distribution, and overall mechanics. Partial limb amputations are becoming more popular for cases in which the amputated limb has an adequate area for prosthetic attachment. As a result, there is a need for prosthetics appropriately designed for partial limbs. While traditional prosthetic production methods rely on subtractive manufacturing, which is costly and time consuming, 3D printing has the potential for rapid prototyping and customization of prosthetics at significantly lower cost. This project aimed to develop a 3D printable trans-radial canine prosthetic that (A) is based on ease of printing, assembly, and cost and (B) on tensegrity principles. The quality of 3D prints from two Fused Deposition Modeling (FDM) 3D printers were compared. Higher cost 3D FDM printers provide better quality of life features in printing; however, our results show that lower cost machines can be almost as capable. While most prosthetic designs are based on rigid mechanics that fail to successfully mimic natural movement, this design was made following the principle of tensegrity to develop a prosthetic that enables better natural movement. A 3D rigged model of a canine skeleton from CT data was created, based on the method used to create a similar equine model, and used to develop prosthetic designs that consisted of a grip around the humeral component of the limb, a central post that socketed the radial stump, and a foot. The components were connected via tensile 3D printed elements that allow passive movement to the carpus when the elbow is moved.