Novel design and comprehensive mechanical analysis of a cost-effective manual patient lifting system with worm gear mechanism

The growing need for efficient patient lifting and transfer solutions highlights a significant gap in current healthcare systems, particularly in affordable, accessible options for home use. While most research has focused on automated or motorised systems, this study introduces a novel manual patient lifting device based on a worm gear mechanism, which, despite its proven industrial benefits, remains underexplored in healthcare. Using a case study of a 50-year-old, 72 kg individual, we developed a cost-effective, manually operated lifting system aimed at reducing caregiver workload and improving patient mobility. The design was modelled using SolidWorks and subjected to comprehensive static and dynamic structural analysis under loads of 800 N, 1000 N and 1200 N. Results show that the worm gear mechanism reduces required torque by up to 66% and applied force by 15% compared to traditional lead screw systems, significantly enhancing ergonomic efficiency. Additionally, lifting speed improves by approximately 10 mm/s, and the device achieves a safety factor of 2.9 under maximum load, ensuring structural reliability. Importantly, the non-back driveable feature of the worm gear prevents unintended descent, addressing a key safety concern in manual lifting devices. This mechanically optimised and ergonomically designed solution is tailored for homecare settings, where affordability, ease of use, and portability are crucial. By applying advanced mechanical principles to a simple, reliable design, this work contributes to the development of practical assistive technologies that improve both caregiver safety and patient independence, marking a meaningful step forward in assistive healthcare technology.