Comparison of the omron HEM-637 wrist monitor to the auscultation method with the wrist position sensor on or disabled

Abstract Background To determine whether the Omron HEM637 wrist model with the wrist positioning sensor turned on (Son) is more accurate relative to upper arm auscultation by trained professionals than when the sensor was manually turned off (Soff). Methods Forty-four subjects, at least 30 years old, had repeated, sequential dual-observer upper arm auscultatory measurements (5 to 6 each) and oscillometric Omron HEM637 wrist measurements (4 each). Nineteen subjects were assigned to the wrist sensor On group and 25 were assigned to the wrist sensor Off group. A total of 425 auscultatory and 164 wrist measurements were analyzed. Results The Omron HEM-637 measured the blood pressure (BP) with equal accuracy to the observers using the auscultatory technique (difference −1.37 ± 8.51/3.47 ± 8.07 mm Hg, P = .71/.14). The wrist sensor did improve the accuracy of the measurements compared to the subjects that had the sensor deactivated. The sensor On group (Son) measured the systolic BP (0.82 ± 9.83 mm Hg) and diastolic BP (−0.72 ± 9.07 mm Hg) statistically the same as by auscultation (P = .86 for systolic BP and P = .83 for diastolic BP). The sensor Off (Soff) group measured the SBP (−3.03 ± 7.12 mm Hg) and diastolic BP (−5.56 ± 6.68 mm Hg) statistically different than auscultation (P = .46 for systolic BP and P = .02 for diastolic BP). The higher (negative) measurement for both the systolic BP and diastolic BP suggests that the average position of the wrist was 1.75 inches (4.4 cm) below the heart level in this group with the sensor off. Conclusions This study demonstrated that the Omron HEM-637 monitor with a wrist sensor more accurately measured BP compared to the same model with the sensor