Abstract: A quality control system for patient monitors is disclosed. The quality control system can include a quality check insert having optical properties. In an embodiment, the insert is placed within a sensor, irradiated with light, and then the light is detected after attenuation by the insert. The detected light is processed using the same or different processing methodologies typically used to determine measurement values for physiological parameters of a monitored patient. When a patient monitor is functioning properly, the results of the processing provide values within a predetermined range of values. When the patient monitor is not functioning properly, the results of the processing provide values outside the predetermined range of values. The quality control system can include quality control parameters indicative of a properly functioning active pulse motor of the sensor, emitters of the sensor, detectors of the sensor, accelerometers of the sensors, and/or temperature sensors of the system.