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Validation of acoustic voided volume measure: a pilot prospective study



We evaluated the accuracy and reliability of a new smartphone-based acoustic voided volume (VV) measurement application compared to VV estimation based on the measurement of urine volume in a bladder by ultrasound bladder scan.

Patients and methods

A total of 53 subjects from 01/2021 to 09/2021 were prospectively enrolled. Bladder scan-based VV estimation is based on the difference in the volume of urine in a bladder measured before urination and volume measured after urination. The acoustic VV measurement is based on smartphone-based acoustic VV measurement mobile application. VV estimates for the same void were compared between two techniques. Urinary measures were obtained from 49 male subjects resulting in a total of 245 measurements for analysis. VV measures were compared using Pearson’s correlation coefficient (PCC), evaluation of observed versus predicted VV measures using linear regression fit indices, and Bland–Altman method.


VV between the two techniques revealed strong correlation (PCC 0.811, p < 0.001). Means of the number of measurements per patient and inpatient days for measurements analyzed are 5 and 2.7, respectively. In 245 measurements, VV measured by bladder scan is 238.69 ± 122.32 mL, VV measured by mobile application is 254.69 ± 119.28 mL, and their difference of two measurements is 16 ± 74.29 mL.


Through the comparison with VV estimated by ultrasound bladder scan, which is a technology to measure the urine volume in a bladder, it was confirmed that the smartphone-based acoustic VV measurement application proudP® is accurate.

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Fig. 1

Data availability

The original contributions presented in the study are included in the article, and further inquiries can be directed to the corresponding author.



Body mass index


International Prostate Symptom Score


Overactive Bladder Symptom Score


Pearson correlation coefficient


Maximum flow rate


Quality of life


Root-mean-square error


Standard deviation


Voided volume


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This work was supported by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, the Ministry of Food and Drug Safety) (Project Number: 1711138269, RS-2020-KD000141) (NTIS, RS-2020-KD000141). This work was also supported by the Grant no. 14-2021-0045 from the SNUBH Research Fund.

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Authors and Affiliations



HK and SL contributed to conceptualization, methodology, validation, investigation, visualization, project administration, data curation, and writing—original draft preparation, and provided software; HK, CY, GJ, and SL were involved in formal analysis; HK, GJ, SJJ, and SL contributed to resources; HK, HR, JWL and SL were involved in writing—review and editing; and SL contributed to supervision and funding acquisition. All authors have read and agreed to the published version of the manuscript. All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.

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Correspondence to Sangchul Lee.

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Kim, H., Ye, C., Jung, G. et al. Validation of acoustic voided volume measure: a pilot prospective study. World J Urol 41, 509–514 (2023).

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  • New device
  • Uroflowmetry
  • Acoustic volume measurement
  • Urine volume measurement
  • Voiding dysfunction