RecruitingDevice studyRespiration From Pleth ValidationThis observational clinical investigation evaluates the performance of respiratory rate derived from the plethysmography waveform (Respiration from Pleth, RfP) using Philips FAST Pulse Oximetry technology. Adult and pediatric inpatients will undergo noninvasive monitoring using age- and weight-appropriate SpO₂ sensors and capnography, with capnography serving as the reference standard. The study assesses accuracy, mean bias, precision, and time to first valid respiratory-rate value across continuous and spot-check conditions. No device outputs are used for clinical decision-making, and all procedures occur during a single study visit.