Backgroud: Our goal was to evaluate the performance of a new wearable arm located pulse oximeter.Methods: Twelve volunteers were monitored with three pulse oximeters and underwent desaturation to 70% SaO2 . We compared the accuracy of SpO 2 reading from the SmartCardia system with SaO2 using two well established devices (Masimo and Nellcor ) as reference.Oximetry was performed at different level of oxygen saturation varying from 70 to 100%. Bias, ARMS and precision were evaluated using

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... man plots.Results: The mean (SD) differences between SpO2 compared to SaO2 and the devices were as follows: SaO2 versus Masimo 2,12±1,01% (95% CI 1,45 to 2,79), SaO2 versus Nellcor 0,78±0,58 % (95 % CI -0,29 to 1,65) and SaO2 versus SmartCardia 0,42±0,24 % (95% CI -0,64 to 1,46). The bias between SmartCardia, Masimo, Nellcor devices and SaO2 was 0.16 (95% CI 0.05 to 0.33) and LoA (level of agreements) 2.96 (95% CI -2,68 to 2,89) for SmartCardia, 2,02 (95% CI 1,49 to 2,54) and LoA -6 to 11 for Masimo, and 0,76 (95% CI 0,5 to -1) and LoA -3,5 to 5,0 for Nellcor. ARMS for the 70-100% SaO 2 range was 1,4 for SmartCardia, 5,0 for Masimo and 2,31 for Nellcor.Conclusions: The new wireless SmartCardia SpO2 measurement system demonstrated in-line results, bias, ARMS and precision in healthy volunteers, when compared with the gold standard SaO2 and with two well established systems, Masimo and Nellcor.Trial registration: The present trial was prospectively registered at UCSF record (registration number:10-00437), on March 8, 2021.