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. Author manuscript; available in PMC: 2013 Oct 19.
Published in final edited form as: Anesth Analg. 2012 Dec 7;116(1):198–204. doi: 10.1213/ANE.0b013e318271fb10

Figure 1.

Figure 1

A schematic diagram of the prototype near infrared spectroscopy (NIRS) based autoregulation monitor and the additional equipment used in the study. Digital signals from the same standard Invos™ 5100 monitor (Covidien, Boulder, CO) were simultaneously sampled by the personal computer (pc) based system and the prototype monitor. Arterial blood pressure (ABP) signals were digitized with an analog-to-digital convertor (ADC) that was internal for prototype monitor. Mean velocity index (M×) and cerebral oximetry index (CO×) cerebral oximetry index were then calculated as the Pearson correlation coefficient between blood pressure and transcranial Doppler (TCD) cerebral blood flow velocity or cerebral oximetry signals, respectively (see text for details). Note: ICM+ (University of Cambridge, Cambridge, UK) software was used for the pc-based autoregulation monitoring.