Noncontact Imaging Plethysmography for Accurate Estimation of Physiological Parameters
In this paper, a novel non-contact device that accurately measures physiological parameters is proposed. This system consists of a CCD camera and a set of band pass filters. To eliminate the noise from the original signal, threshold segment and image registration algorithm are used. In addition, motion artifact is a vital issue that cannot be ignored. Here, an adaptive filter based on wavelet transform is introduced to reduce the motion artifact. Besides, the influence of ambient light intensity is discussed, which the result demonstrates that the change of ambient light intensity has no obvious impact on measurement results. Compared with the traditional contact method, this method is more convenient when mechanical isolation is required. Contrast experiment was performed with a multi-parameter monitor and a CO-oximeter. The comparison showed that our method is comparable with the contact method.