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Fig. 1 | BMC Anesthesiology

Fig. 1

From: Comparison of accuracy of two uncalibrated pulse contour cardiac output monitors in off-pump coronary artery bypass surgery patients using pulmonary artery catheter-thermodilution as a reference

Fig. 1

The Retia Argos device computes cardiac output (CO) by multi-beat analysis of a radial arterial blood pressure (ABP) waveform [8,8,9,10,11,13]. The ABP response to a single heartbeat [h(t)] is estimated from the ABP waveform segment over multiple beats via mathematical modeling. The Windkessel time constant τ, which equals the systemic vascular resistance times the arterial compliance (AC), is then determined by fitting an exponential to the tail end of this response once the faster wave reflection vanishes. Finally, CO is computed by dividing mean arterial pressure (MAP) by τ and determining the AC term from ABP and patient demographic information via a proprietary formula

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BMC Anesthesiology

ISSN: 1471-2253

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