In Vivo Forces of Male Urethral Catheterization

Abstract

The purpose of this study was to quantify typical urethral catheter insertion forces of male anatomy in vivo. This provided a quantitative range of forces that may be used to objectively evaluate trainees or educational simulators. A custom-made Handheld Catheter Insertion Force Assessment tool (+/- 0.29N accuracy) was used to capture force profiles of (n=16) urethral catheterizations of (n=12) unique older (52-92 years) living male patients by a single urologist under IRB 00003363. Across all catheterizations, insertion force range was found to be 81.2gf (0.796N) to 509gf (4.99N). The resulting mean was 185gf (1.81N), the median was 163gf (1.60N), and the standard deviation was 72.8gf (0.714N). Substantial force variation was observed within each trial. The average maximum force per trial, associated with bladder entry, was 306gf (3.01N). These measurements differed substantially from postmortem and physical simulation measurements. To be more realistic, changes in mechanical properties of simulator design are necessary.