8Hayes MJ, Smith PR. Artifact reduction in photoplethysmography [J]. Appl Opt,37(31) :7431 - 7446.
9Swedlow DB. Oximeter with motion detection for alarm modification [P]. International Patent Application WO 94y22360 -13 October 1994.
10Frans M, Coetzee and Ziad Elghazzawi. Noise-Resistant Pulse Oximetry Using a Synthetic Reference Signal[J]. IEEE Trans Biomedical Engineering, 2000, 47(8): 1018- 1026.