Design and Optimization of a Novel Intramedullary Robot for Limb Lengthening

ShiKeat Lee, Zhenguo Nie, Handing Xu, Kai Hu, Zhao Gong, Qizhi Meng, Fugui Xie, Xin-Jun Liu

Abstract: Limb length discrepancy is a crucial problem that can seriously affect the life quality and likely leads to other diseases. Free from extracorporal surgery, the intramedullary limb-lengthening treatment has become increasingly popular in recent years as a method of long-bone distraction osteogenesis. To overcome the mechanical and electromagnetic problems caused by the medical device miniaturization, this paper presents a study on the design and optimization of a novel Intramedullary Robot for Limb Lengthening (IR4LL) with robust mechanical stiffness and surplus electromagnetic driving force. A solenoid-driven design with a large reduction ratio is proposed and analyzed. Based on the experimental and simulation results, IR4LL is proven to be safe and reliable for limb-lengthening operations, which can significantly reduce lifestyle disruption and medical complications during and after the treatment.