A novel sensor (a device named sensurine)was developed in the aim of real- time measurement of bladder volume. The sensurine device is a wearable, fully passive, non-invasive and compact heat flow sensor (patent pending) and electronic control unit. The device will serve as a tool for managing and treating bladder dysfunction (by behavioral treatment), such as overactive bladder without incontinence, urge incontinence and voiding difficulties. In this phase I of the clinical trial the sensor unit will be tested for technological feasibility demonstration and for collecting design data.