Development and Automation of a Robotic Hexapod Device for Orthopedic Applications

This paper presents a preliminary study on the development and automation of a robotic hexapod system for orthopedic applications, specifically aimed at enhancing external hexapod fixators used in bone fracture treatments. Traditional hexapod systems are constrained by the fixed elongation range of their struts, often necessitating multiple replacements throughout the treatment process. These replacements introduce inefficiencies and pose risks to maintaining proper alignment. The innovation proposed in this study is the design and development of an advanced telescopic strut system, referred to as the T-Strut, which significantly extends the available elongation range without requiring replacement. A significant accuracy in elongation adjustment can be achieved thanks to the adopted motion transmission system, which, even with substantial rotations of the wheel, results in very small lengthening or shortening. This paper details the mechanical design of the T-Strut, its integration with a motorized worm gear mechanism, and the incorporation of an optical encoder for precise measurement and feedback. Additionally, the system is supported by custom software that automates the control and adjustment of the struts based on predefined treatment plans, improving both the accuracy and safety of the fixation process. By automating adjustments, reducing manual intervention, and maintaining alignment throughout the treatment, this system offers a promising solution for advancing current orthopedic fixation methods.