While evaluating a new domestically produced pulse oximeter model in clinical practice, we discovered a lack of references in Russian-language publications on clinical trial methodologies to assess device reliability and performance.The aim of the study is to create a methodology for conducting a multicenter, prospective, cohort, nonrandomized, controlled clinical trial evaluating a domestic pulse oximeter.Methods. Measurements were performed on 20 preterm infants in the neonatal intensive care unit with a mean birth weight of 2340 [1250; 3125] g and a gestational age of 35 [30; 37] weeks using a new model pulse oximeter simultaneously with the reference monitor. Multiple oxygen saturation measurements of varying duration were taken alternately from the upper and lower limbs, and the number of false desaturation alarms was recorded. Pulse oximeter saturation data were evaluated for correlation with clinical findings.Results. Attachment of sensors to the infant's feet was found to be optimal in terms of ease of use, minimal artifact generation, and minimal interference with routine medical procedures and neonatal care. To reduce motion-induced artifacts and false alarms, the optimal period of SpO₂ monitoring to detect desaturations and bradycardia was determined to be 120 min. Due to the high variability of pulse rate (PR) and saturation in neonates, two-second intervals were determined to be optimal for comparing records from the two monitors. Matching of ECG HR and pulse oximeter PR was required to eliminate artifacts. A mathematical software model required for accelerated analysis of data collected from all sensors during the study was approved.Conclusion. The data analysis supported the proposed methodology for conducting a clinical trial to evaluate the performance and reliability of new pulse oximetry devices.