Can a simulator that regenerates physiological waveforms evaluate oscillometric non-invasive blood pressure devices?

Abstract

A simulator has been developed that enables previously recorded clinical oscillometric waveforms to be regenerated for testing oscillometric non-invasive blood pressure measurement devices. Two non-invasive blood pressure devices were evaluated using the simulator with its database of 243 waveforms, to assess the value of a simulator for such evaluations. Two oscillometric non-invasive blood pressure devices, both of which had previously been validated against auscultatory references, were selected. The Omron HEM-907 (Omron, Hoofddorp, The Netherlands) measures the pressure during linear cuff deflation and the GE ProCare 400 (GE Healthcare, Tampa, Florida, USA) measures during step deflation. Each non-invasive blood pressure device was attached to the simulator and pressures were recorded from all 243 waveforms. The differences between the systolic and diastolic pressures measured by each non-invasive blood pressure device and the auscultatory references for each waveform were calculated. These were assessed with the European and American validation standards and with the British Hypertension Society protocol. The paired pressure differences (non-invasive blood pressure device minus auscultatory reference) for each device complied partly, but not fully, with the standards or protocol. The means (+/-standard deviation) of the paired systolic and diastolic pressures differences for the Omron were -2.4 mmHg (+/-5.9 mmHg) and -8.9 mmHg (+/-6.5 mmHg), and for the ProCare were -6.5 mmHg (+/-10.4 mmHg) and -2.9 mmHg (+/-7.0 mmHg), respectively. The pressures recorded by the Omron device met the standards for systolic pressures but failed for diastolic pressures and conversely for the ProCare. This represents the first evaluation of non-invasive blood pressure devices with a simulator that generates previously recorded clinical oscillometric waveforms. It allowed data from over 100 study participants to be used. Both devices had been previously clinically validated, but their evaluation using the simulator with its regenerated waveforms only partly met the required criteria. Although the results did not fully match previous clinical validations, these initial results give encouragement that a simulator with sufficient stored waveforms might be able to replace the difficult and expensive clinical evaluation of non-invasive blood pressure devices that has prevented many devices from being fully evaluated.