Evaluating Measurement Consistency of Palm Grip Device Through Multi-Phase Clinical Testing

Accurate assessment of grip force is essential in rehabilitation, particularly for monitoring motor recovery and spasticity in patients with neurological conditions. This study outlines the iterative development of a palm grip device using rapid field-testing. Over four design phases, the hardware evolved from a basic USB-powered setup to a battery-operated system with improved sensor stability, ergonomic fit, and integrated feedback. Testing involved six patients interacting with various objects (cylindrical, rectangular, cubic, and soft) allowing evaluation across different grip types. Standard deviation and coefficient of variation (CV%) metrics were used to assess measurement consistency. Results indicated lower variability for cubic and soft objects, while cylindrical items exhibited higher fluctuation due to grip instability. Progressive hardware improvements significantly reduced overall variability, demonstrating the impact of patient-informed design. The study emphasizes the value of integrating rapid field-testing into medical device development to ensure both functional reliability and clinical relevance.