Method and associated controller for life sign monitoring
A method for life sign monitoring and associated controller is provided. The method includes: obtaining a video signal, performing an activity modeling on the video signal to provide an activity signal, performing a vital sign extraction on the video signal to provide a vital sign, performing a filtering on the vital sign in view of the activity signal to suppress a correlation between the activity signal and the vital sign, and accordingly providing a filtered vital sign; and, according to the filtered vital sign and whether the activity signal exceeds an activity threshold range, providing a joint decision for categorizing result of life sign monitoring to one of a plurality of predetermined episodes.
1. A life sign monitoring controller, comprising:
an interface circuit for obtaining a video signal;
an activity modeling circuit for performing an activity modeling on the video signal to provide an activity signal;
a vital sign extraction circuit for performing a vital sign extraction on the video signal to provide a vital sign; and
a filter circuit for performing a filtering on the vital sign in view of the activity signal to suppress a correlation between the activity signal and the vital sign, and accordingly providing a filtered vital sign.
2. The controller of claim 1 further comprising:
a joint decision maker for providing a joint decision for categorizing result of life sign monitoring to one of a plurality of predetermined episodes, according to the filtered vital sign and whether the activity signal exceeds an activity threshold range.
3. The controller of claim 1 , wherein the filter block comprises:
a buffer for buffering an amount of preceding samples of the activity signal;
a weighting module for weighting the amount of preceding samples respectively by a same amount of weighting coefficients, summing the amount of weighted preceding samples, and accordingly providing a current sample of a weighted signal; and
an arithmetic node for subtracting the weighted signal from the vital sign to provide the filtered vital sign.
4. The controller of claim 3 further comprising:
an adaptive unit for adjusting the weighting coefficients according to the filtered vital sign.
5. The controller of claim 1 , wherein the vital sign extraction block performs the vital sign extraction by identifying an ROI from each of a plurality of frames of the video signal; and performing a pixel operation on pixels of a number of ROIs to provide a sample of the vital sign.
6. The controller of claim 1 , wherein the filtered vital sign comprises a plurality of channel signals, and the controller further comprising:
a vital sign derivation block for:
performing an ICA on the channel signals, and accordingly providing a plurality of component signals; and
providing a derived vital sign according to the component signals.
7. The controller of claim 6 , wherein the vital sign derivation block is further for:
performing spectrum analysis on the component signals to obtain spectrums; and
identifying a characteristic value of the spectrums to provide a sample of the derived vital sign.
8. The controller of claim 1 further comprising:
a vital sign derivation block for:
providing a first derived vital sign and performing a signal pre-processing on the first derived vital sign;
performing an ICA on the pre-processed first derived vital sign and the vital sign to provide a plurality of component signals;
providing a second derived vital sign according to the component signals.
9. The controller of claim 1 , wherein the activity modeling block performs the activity modeling by identifying an ROI from each of a plurality of frames of the video signal; and performing an ROI operation on a number of ROIs to provide the activity signal.