Vivaray Hb pro noninvasive 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 ({beta}? = -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.