Development of an electromechanical handbike prototype attachable to conventional wheelchairs

Mobility limitations among individuals with lower limb impairments often lead to overuse of the upper limbs, resulting in pain, fatigue, and long-term musculoskeletal injuries. Although electric wheelchairs improve mobility, their high cost limits access in low- and middle-income regions. To address this gap, we developed and evaluated a low-cost electromechanical handbike prototype designed to be easily coupled to standard manual wheelchairs. Using the V-model methodology for mechatronic systems, the design process included functional specification, Computer-Aided Design (CAD) modeling, structural simulation, and physical prototyping. The chassis was constructed from chromoly steel with a reinforced coupling mechanism, and the propulsion system integrated dual motors, a controller unit, and lithium-ion batteries. Structural simulations showed maximum von Mises stresses of 1.74 MPa on the fastener and 2.67 MPa on the chassis, with safety factors above 100, indicating strong mechanical performance. Field testing in Bucaramanga, Colombia—with participants using the device over varied terrain—demonstrated an average autonomy of 12.4 km per charge and high ergonomic adaptability. These results support the viability of a robust, affordable, and easy-to-maintain mobility solution. The proposed handbike enhances user autonomy and comfort, contributing to broader accessibility and improved quality of life for wheelchair users in resource-limited settings.