“…1, 3,8,23 It is estimated that about 13% of the general and up to 60% of the geriatric population in the United States have some form of INV malfunction. 24 Methods for diagnosing this condition either are subject to examiner variability, suffer from poor reproducibility, or are very time-consuming. Therefore, it is not surprising that currently, no gold standard test has been defined to diagnose obstruction of the INV.…”