Table 2. The measurement error of the Lilium α-200 portable bladder scanner in voided volume or PVR.

Characteristic	Number	Measurement error (mL) (mean±SD)
Voided volume (all)	316	−21.0±102.0
Voided volume (accurate)	181	4.3±53.3
Voided volume (inaccurate)	135	−55.2±136.3
PVR	34	2.4±52.0

Data from the portable device within ±30% of data for conventional frequency-volume charts were defined as “accurate”, whereas data with greater measurement error were defined as “inaccurate”.

PVR, postvoid residual urine volume; SD, standard deviation.