A Seoul National University Bundang Hospital (SNUBH) research team has developed a technology to automatically measure urine volume by analyzing urine sounds using a smartphone.

The urinary system, which consists of the kidneys, ureters, bladder, and urethra, removes wastes from the body through urine and regulates the ratio of water and salt. The body produces a certain amount of urine each day to cleanse the body. However, the amount of urine produced can be significantly lower or higher than average when there are functional abnormalities in the urinary system.

There are many diseases that hospitals can detect through this change in urine output. For example, a decrease in urine volume is a typical symptom of prostate enlargement or renal failure.

To accurately identify these changes in urine volume, however, patients had to always carry a measuring container with them or install an expensive medical urine pattern measuring device at home, which is not practical. As a result, most patients had to rely on their subjective feelings to judge their urine volume, which is problematic because it can lead them to miss the opportunity to diagnose certain diseases on time.

To resolve this issue, the team, led by Professor Lee Sang-Chul of the Department of Urology, developed a smartphone-based technology that analyzes the sound produced when urine hits the surface of the water during urination to calculate the total amount of urine produced.

The team developed the platform using the idea that the intensity of urine discharge is proportional to the bladder's detrusor pressure, which is the pressure generated by the urine flow through the urethra per hour.

Afterward, the team conducted a prospective study of 57 patients to validate the accuracy of the technique.

Professor Lee's team cross-checked 245 urine volume measurements in the bladder from an ultrasound scan performed before voiding with measurements from a sound analysis algorithm during voiding.

The results showed that the difference between the two methods was 16cc on average, which is relatively high considering that an adult male urinates around 200cc.

The team stressed that the research results are significant as they showed that the developed algorithm has high accuracy and paved the road for a research methodology utilizing ultrasound that could become a standard in sound-based measurement methods.

"From the patient's point of view, being able to check the amount of urination in a private space can reduce the mental burden of urinating in a laboratory, which can lead to measurement errors," Professor Lee said. "In addition to self-diagnosis, it will also be conducive for medical staff to more accurately determine the patient's urination status and prepare customized treatment strategies."

He added that the hospital plans to validate and develop the technology through more samples, from healthy people to patients with urination disorders.

World Journal of Urology published the result of the study in its latest issue.