Unintentional body movement parameters and pulse rate variability parameters are associated with the desire to void

Urinary incontinence is highly prevalent in elderly populations with physical and cognitive impairment. For the assessment and care of urinary incontinence, the desire to void is important. We have developed a bed sensor system that non-invasively and unconstrainedly measures the parameter changes of unintentional body movements. This study is aimed to evaluate the validity of measurement by the sensor system and parameters in healthy adults. We conducted experiments on 29 healthy adult volunteers. The parameters were unintentional body movement derived from changes in center of gravity and pulse rate variability (PRV) based on pulse wave measurements using a finger probe; further the relationship between the desire to void and measured parameters were examined. The body movement parameters at the buttock and thigh were associated with the desire to void (p < 0.050). All the PRV parameters trended significantly with desire to void as well (p < 0.050). The parameters achieved sensitivities of 0.18-0.88 in estimating strong desire to void, and 7 among 14 sensitivity measurements included in the receiver operating characteristic analysis exceeded 0.70. The body movement parameters and PRV parameters were useful in the estimation of the desire to void in healthy adults. To achieve accurate estimation, a combination of the PRV parameters and body movement parameters is required.