RESUMEN
This paper presents the design and experimental characterisation of a wrist haptic interface based on a twisted string actuator. The interface is designed for controlled actuation of wrist flexion/extension and is capable of rendering torque feedback through a rotary handle driven by the twisted string actuator and spring-loaded cable mechanisms. The interface was characterised to obtain its static and dynamic haptic feedback rendering capabilities. Compliance in the spring and actuation mechanism makes the interface suitable for smooth rendering of haptic feedback of large magnitudes due to the high motion transmission ratio of the twisted strings. Haptic virtual wall rendering capabilities are demonstrated.
RESUMEN
This paper presents the development of wrist ROM measurement system that was implemented on a rehabilitation glove for paretic hand, Easy-Flex, using a rotary potentiometer. This approach enables the device to measure the angles of up to 80° with the approximate resolution of 0.1°. The method along with a universal goniometer and a smartphone clinometer application were tested on 17 healthy participants in terms of reliability. The three instruments were able to accurately measure three different angles (flexion: -10°, neutral: 0°, and extension: 20°) with measurement errors less than 2°. Moreover, ICCs of the proposed method were close to 0.90 indicating the method implemented on Easy-Flex is reliable for measuring wrist flexion and extension measurement.