Fig. 3From: Validity of accuracy and trending ability of non-invasive continuous total hemoglobin measurement in complex spine surgery: a prospective cohort studyFour-quadrant plot compares the consecutive changes in SpHb and tHb. The central exclusion zone was applied at ±1.0 g/dL to rule out the pairs of data with minimal consecutive difference. The concordance rate was 85.11%Back to article page