Nocturnal penile tumescence and rigidity monitoring in young potent volunteers: reproducibility, evaluation criteria and the effect of sexual intercourse.
Level 4 - case-series / case-control
Prospective repeated-measures observational study in a small case series of healthy volunteers without a clinical control group.
PubMed 9598488 · doi:10.1016/S0022-5347(01)63197-5
What was done
Twelve healthy, potent male medical students aged 21 to 24 completed three sessions of 3-night nocturnal penile tumescence and rigidity monitoring using the RigiScan device, with at least 3 days between sessions. During the final 3-night recording, subjects engaged in sexual intercourse at least once. Investigators evaluated 108 total nights across 562 erectile episodes, assessing the best erectile event and hourly normalized rigidity and tumescence activity units.
What was found
All 3-night recording series contained at least 1 erectile episode with tip rigidity greater than 60% lasting more than 10 minutes. Intercourse occurred prior to 18 of the 108 recording sessions and did not significantly affect nocturnal tumescence or rigidity measurements, though non-significant reductions were noted. Normalizing rigidity and tumescence activity units per hour as 3-night session averages produced reproducible values.
Why it matters
These findings provide normative RigiScan criteria (>60% tip rigidity for >10 minutes over consecutive nights) in potent men and suggest that prior intercourse does not invalidate diagnostic testing.
Limits
The study is limited by an extremely small sample size (n = 12) restricted entirely to young, healthy volunteers, precluding direct generalizability to aging men or patients with erectile dysfunction. The abstract reports no numerical dispersion metrics, confidence intervals, or exact p-values.
Cited by
- supports Young males experience nocturnal erections three to five times per night, lasting up to 40 minutes each.