UAS Insertion Depth Predictor

Flexible Ureteroscopy · Ridge Regression Model (α = 10)

Height (cm)

Age (years)

Sex

Side

L1–Pubic Symphysis (mm)

BMI (kg/m²)

Predicted UAS Insertion Depth

34.4 cm

Reference range: 32.4 – 36.4 cm (±2 cm)

Ridge model: Depth (cm) = −0.5895 + 0.1143×Height − 0.0114×Age + 2.0772×Sex + 0.2824×Side + 0.0363×L1 + 0.1376×BMI
Sex: Male = 1, Female = 0; Side: Left = 1, Right = 0

This tool is for preoperative planning reference only and does not replace intraoperative judgment or fluoroscopic confirmation.
The ±2 cm range reflects the anatomical distance from the UPJ to the calyceal mucosa; errors within this range are unlikely to cause mucosal injury.