Comparative Analysis of SpO2 Monitors During Low Perfusion

This technical report presents a comparative study evaluating the accuracy of three pulse oximetry devices—GE HealthCare CARESCAPE, Masimo RADICAL-7, and Medtronic Nellcor PM1000N—during low-perfusion conditions. The study involved healthy adult volunteers and was conducted after obtaining approval from the University of California San Francisco IRB. The methodology included simulating low perfusion using ice-bath immersion and measuring SpO2 readings from both normal and low perfusion states. The Perfusion Index (PI) was utilized as a standard for flow measurement, and induced hypoxia was applied to assess a range of oxygen saturation levels. Results indicated that the overall Accuracy Root Mean Square (ARMS) for the devices varied, with GE HealthCare demonstrating the lowest failure rate in measuring SpO2. The findings suggest comparable performance across the devices under low perfusion conditions, though further clinical evaluation is recommended to assess their effectiveness in real-world scenarios.