Bladder ultrasound devices are widely used for follow-up after catheter removal and bladder function evaluation as a common modality for residual urine measurement in medical settings. In the currently available B-mode bladder ultrasound devices, challenges include the need for a certain technical training depending on the shape and capacity of the bladder such as at low bladder volumes, as well as the price and frequent failures caused by the product's structure. On the other hand, bladder ultrasound devices using A-mode technology is considered advantageous in terms of reasonable price and better durability. However, there is limited clinical evidence for the accuracy compared to the commonly used B-mode ultrasound. Thus, we evaluate the measurement accuracy of the Lilium one, a bladder ultrasound device using A-mode technology in healthy adult male in relation to the estimated urine volume in the bladder at the time of measurement operation using general echoes as a control. In addition, the time required for the measurement of each device will be evaluated.

Six healthy adult males (mean age: 24.5±2.88 years) were injected a fixed volume (injection cool: 50mL, 100mL, 200mL, 300mL, 400mL) of saline solution to bladder via a catheter, measured once with a general echo and three times with the Lilium one. Measurement results were evaluated based on the calculated predictive actual bladder volume at the moments of measurement operation obtained by subsequent urine collection via catheter. We also compared measurement results obtained from Lilium one bladder ultrasound device to that from general echoes. Informed consent was properly held and the study was approved by appropriate certified clinical research review board.

In the comparison of the ultrasound measurements of bladder volume measured by each modality, no significant difference was found between the general echo and Lilium one for the estimated amount of fluid in the bladder. The average time required for the measurement was about 50 seconds for the general echo and about 6 seconds for Lilium one, which was significantly shorter for Lilium one in all sessions (P<0.01).

Lilium one, a bladder ultrasound device using A-mode technology is  convenient and as accurate as B-mode general echo.

The bladder ultrasound device using A-mode technology is as accurate as B-mode general echo in terms of measurement of residual urine. Besides, the bladder ultrasound device using A-mode technology can perform measurements of residual urine in a shorter time, suggesting that it can be used easily in clinical settings.

Continence 7S1 (2023) 100740
DOI: 10.1016/j.cont.2023.100740