Development and validation of a blinded hybrid device according to the European Hypertension Society protocol: Nissei DM-3000.

Both automated and auscultatory blood pressure (BP) devices have their strengths and accuracy limitations. Hybrid devices, such as the Nissei DM-3000, are mercury free and provide both automated and auscultatory measurement modes. The aim of this study was to validate all measurement modes of the Nissei DM-3000 device according to the European Society of Hypertension (ESH) protocol, as well as to develop and validate a 'blinded' auscultatory measurement mode. Different measurement modes were developed and evaluated in separate studies. Nine sequential same-arm BP measurements were taken alternating between simultaneous mercury sphygmomanometer readings and the device. The latter seven measurements were analysed according to the requirements of the ESH protocol. All measurement modes of the device passed the ESH protocol. The blinded mode achieved the best results with a mean difference+/-s.d. of -0.1+/-2.6 and 0.04+/-2.4 mm Hg for systolic BP (SBP) and diastolic BP (DBP), respectively. The most accurate auscultatory measurement results were obtained with a deflation rate of 2.5 mm Hg s(-1) achieving a mean difference+/-s.d. of -0.6+/-4.4 (for SBP) and -1.4+/-2.8 mm Hg (for DBP). The automated mode achieved a mean difference+/-s.d. of -0.8+/-6.0 (SBP) and 0.8+/-4.8 mm Hg (DBP). The Nissei DM-3000 device is a suitable replacement for the mercury sphygmomanometer.