Accuracy of the pulse delay time technique with triple cuff for objective indirect blood pressure measurement

We developed a new technique to measure blood pressure (BP) - the triple cuff and pulse delay time technique (TC-PDT) - which measures delay time with a single sensor at a single site unlike the existing delay time methods. This study aimed to evaluate the adequacy and accuracy of TC-PDT.

TC-PDT measures delay time, which represents the difference in the arrival time of the arterial pulse wave between the proximal and distal areas of the cuff and provides clear criteria for BP determination based on the mechanism. Adequacy of delay time in TC-PDT was confirmed in comparison with established delay time of the pulse transit time technique (PTT). TC-PDT accuracy was evaluated according to the standard guidelines.

In TC-PDT, delay time showed changes in parallel with those observed in PTT. The correlation coefficient between BP by TC-PDT and that by PTT was 0.98 (P < 0.01) for SBP and 0.93 (P < 0.01) for DBP. According to the International Protocol guidelines (2002), the BP measurements of 33 patients met the recommended values for phase 1, 2.1 and 2.2 measurements. As per the Association for the Advancement of Medical Instrumentation (AAMI) SP10 guidelines (2002), the mean difference in BP measured by TC-PDT and that measured by the auscultatory technique in 85 patients was 1.0 ± 5.1 mmHg for SBP and -0.4 ± 4.5 mmHg for DBP, which conformed to the requirements.

TC-PDT is adequate to measure delay time and provides adequate and accurate measurements of BP. This device has the potential to be a standard tool for indirect BP measurement.