Noninvasive measurement of elastic properties in human finger arteries: clinical data comparing blood pressure and funduscopic examination.

A portable device equipped with a transmitted infrared photoelectric plethysmograph (TIPP) and compression cuff was designed for indirect estimation of elastic properties of the arteries. Volume elastic modulus (Ev) was noninvasively measured by the device at controlled transmural pressure (Pt) levels in the finger arteries of 116 normal subjects and 50 patients with hypertension. Finger arterial pressure was simultaneously measured by this device using a volume oscillometric technique. There was a nonlinear relation between Ev and Pt, as reported previously by other investigators. Ev increased with Pt showing a minimum at Pt of about 0 mmHg. The Ev values increased with age and were higher in men than in women, when the same age groups were compared. The averages of the normal values were determined from regression equations relating Ev and age with respect to Pt and sex, assuming that there is an exponential relation. The normal range was tentatively determined as +/- 25% of the average Ev. The average Ev values obtained from the hypertensive patients (69 +/- 8 years old, n = 21 for males; and 70 +/- 11 years old, n = 29 for females) were significantly higher than the average normal values when same age groups at Pt = 60 mmHg were compared. Twenty-seven (54%) of the patients showed higher and 10 (20%) lower values than the normal range, while 13 patients (26%) were within the normal range at Pt = 60 mmHg. A significant correlation was not observed between the Ev values and the systolic, mean, and diastolic pressure values in the finger arteries of the hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)