Vivaray Hb pro non-invasive hemoglobin device: A prospective diagnostic accuracy study measuring agreement with a calibrated blood cell counter

Background Non-invasive hemoglobin measurement offers a painless and rapid alternative to conventional blood-based testing. The Vivaray Hb pro is a handheld photoplethysmography-based device designed for point-of-care hemoglobin assessment without blood sampling. We evaluated the clinical performance of the Vivaray Hb pro by comparing device-generated hemoglobin values with those obtained from a calibrated laboratory blood cell counter. Methods In this cross-sectional, non-randomized clinical performance study, participants aged ≥8 years were prospectively recruited. Hemoglobin was measured non-invasively using the Vivaray Hb pro and compared with venous blood samples analyzed on a calibrated Coulter counter. Agreement between methods was assessed using Bland–Altman analysis, including regression-based evaluation for proportional bias. Mean absolute error (MAE) and proportions of measurements within tolerance limits were also calculated. Complete paired measurements were available for 763 individuals. Results Bland–Altman analysis demonstrated hemoglobin-dependent bias, with overestimation at lower hemoglobin levels and underestimation at higher levels. Regression-based analysis showed proportional bias (β 1 = −0.178), indicating decreasing difference with increasing hemoglobin concentration. The MAE was 1.5 g/dL but was lower (1.2) in the clinically predominant ranges of 8.1-13 g/dl. Comment The results support the use of the Vivaray Hb pro as a noninvasive hemoglobin screening and point-of-care assessment tool, particularly in settings where rapid, painless, and repeatable measurements are desirable.