Thermistor Based Automated Urine Volume Detection Method

Measuring the urine output of the patients regularly is critical for the medical treatment of many diseases. Currently, it is done by manually measuring the hourly urine output which is cumbersome, time-consuming, stressful for the caregivers, and prone to errors. This study presents a device that can be used to automatically measure the urine volume using a Negative Temperature Coefficient (NTC) thermistor-based sensor and an electronic device. A control circuit was developed to detect drops of urine falling on the disposable thermistor sensor. The circuit amplifies the voltage signal from the sensor in addition to keeping the thermistor at a fixed temperature. The voltage signal was converted to digital form and processed by an algorithm that was developed to identify individual drops. The number of drops was then converted to a volume by multiplying by the volume of a drop. The device was calibrated and tested for accuracy using water. Future work is planned for testing the device for the measurement of urine under clinical settings. This study addresses the problem of manual urine collection of dengue patients and is also applicable for any other drop detecting applications.