On the first visit, the subject will sign an informed consent form. A medical intake including demographic data will be collected. Stage 1 will serve for basic testing of the sensor unit and for measuring the maximal and minimal bladder volume. The sensor will be attached to the lower abdomen wall and checked for functionality. Each subject will fill up his bladder (by drinking water) until sensing a strong urge to void. The subject will then void until he is empty into a measurement cup. Ultrasound measurement (US) of bladder volume, and sensor signal will be read and recorded by a standard miliVoltmeter just before and immediately after emptying the bladder. Sensor, US and cup measurement readings will not be done by the same investigator. Continuing to stage 2 will depend on the preliminary results (sensor readings compared to the measured volume and US readings) determining feasibility.. Stage 2 will serve for measuring the dynamics of bladder heat conductivity during the filling and voiding phases. On the 2nd visit the subject will fill up his bladder by gradually drinking 500CC of water (over 60-90 minutes) until sensing a strong urge to void. The subject will drink an additional 50-100CC of water and wait around 10 minutes in the aim of achieving maximal bladder capacity. The sensor signals will be recorded from the beginning of this bladder filling stage every 5-10 minutes. Then, the subject will be requested to void in a controlled manner and to intentionally stop urinating after emptying 50-100CC of urine (voided volume will be determined by the measurement cup). The controlled voiding of 50-100CC will be repeated until the bladder is empty. The sensor signals will be read and recorded during both stages. Visit 3 will be performed in the same manner but in different positions during measurements (supine-on the back, sides and front, sitting, and standing). Visit 4 (final visit) will serve for demonstrating the sensor unit’s performance in different ambient temperature and clothing. Two subjects will be randomly selected to examine the sensor in an ambient of 15ºC (this will be controlled by an air-conditioned room with an external thermometer) for measuring the dynamic range (maximal and minimal bladder capacity). The same will be done at room temperature twice- with light and heavy clothing. The other 2 subjects will be randomly selected to examine the sensor's performance in an ambient of 40ºC (hot temperature will be achieved by an electric heater in a small room controlled with an external thermometer) for measuring the dynamic range (maximal and minimal bladder capacity). The same will be done at room temperature twice- with light and heavy clothing.