1. A pulse oximetry system for the determination of a physiological parameter wherein said pulse oximetry system is configured to remove motion artifacts from physiological signals, comprising: an optical sensor for providing said pulse oximetry system with photo-plethysmographic data, wherein said sensor comprises a light emitting diode for emitting light and a photo-detector for detecting said light, wherein said detected light contains information on the photo-plethysmographic data; and a processor for processing the photo-plethysmographic data, wherein said processor is configured to: (a) acquire said photo-plethysmographic data; (b) transform the photo-plethysmographic data into frequency domain data; (c) analyze the frequency domain data to determine a result; (d) determine a time domain data photo-plethysmographic signal using said result of said analysis of said frequency domain data; (e) analyze a mathematical transformation of the time domain photo-plethysmographic signal to identify parameters; (f) use said parameters to determine whether an artifact is present and to identify a physiological signal; and (g) determine a physiological parameter from said physiological signal.