A Cable-Driven Exosuit for Bidirectional Upper Limb Resistance Exercises

Recently, intensity-adjustability, interactivity, and multi-functionality have become crucial features of home fitness devices. To accommodate these features, there has been a demand for a new type of device, leading to the development of both passive and active cable-driven exosuits. These exosuits demonstrate features of intensity-adjustability and interactivity. However, there is further potential for development in terms of multi-functionality. This letter presents the development of a cable-driven exosuit for the upper limb home fitness capable of transmitting bidirectional resistance. In this exosuit, two types of cable routing were established for each direction of resistance. Due to the characteristic of cables transmitting force only by tension, these cable routings were designed to allow the increase in cable length, while enabling the appropriate direction in torque to be transmitted for various exercises. Additionally, routing anchors are designed to minimize the influence of friction in various postures. To enable resistance adjustment, a derail-preventing actuator with a force sensor has been applied. In the verification of the exosuit, muscle activation analysis was conducted on three healthy participants. We confirmed the activation of six upper limb muscles through various intensities and observed that the exosuit can alter muscle activation patterns differently from the resistive bands.