In this study, we assessed the physical burden on professional caregivers when using a transfer support robot, "Hug," to transfer and move a care recipient. We compared heart rate (HR), heart rate variability (HRV), and the time-series synchronization between HRV and respiration in caregivers using the robot or a normal wheelchair as control. Under both conditions, a commercial wearable device was used to simultaneously obtain electrocardiogram and respiration signals while performing care tasks, which comprised transfer from a bed to a wheelchair or to the robot, movement to a remote location, and transfer to a chair. We found that HR was significantly higher and HRV and wavelet coherence were significantly lower in the control than with Hug during at least the first 30 seconds of rest after the task (p < 0.05). This suggests that Hug could reduce the increase in HR and thereby maintain a more constant rhythm between HRV and respiration during care tasks. A post-task questionnaire also revealed that caregivers felt the physical burden of the tasks was reduced using Hug. Our results suggest that the introduction of transfer support robots can reduce the physical burden for caregivers of daily transfer assistance tasks.
Keywords: care task; electrocardiogram; physical burden; respiration; transfer support robot.