Abstract
A new ultrasonic urine sensor is developed for measuring the urine accumulation in the human bladder. Intensive observations are made on the bladder expansion process under the gradual accumulation of urine by using a magnetic resonance imager. It is observed that the primary changes in shape take place at the top and very small changes occur at the bottom. These findings help to establish a simple and yet reasonable mechanism for the bladder measurement because the variations in the height of the bladder can be easily ascertained with a proposed PD index in terms of the application of ultrasound beams. The principle of measurement is evaluated in a clinical test and a strong monotonic tendency is identified between the urine accumulation and the proposed PD index. Design of the new ultrasonic urine sensor is then conducted and further experimental tests are carried out with the apparatus developed. It is found that the new ultrasonic urine sensor can really display a very good indication of the urine accumulation in the bladder. The new ultrasonic urine sensor is already commercialized and has received high appraisal from a great number of users. It is characterized by non-invasive measurement, small volume, low weight and affordable price, thereby permitting easy access by various patients including older adults.
