HUTCHINSON, Nicholas Dunkley,JONES, Simon Mark Chave,FRAZ, Muhammad
申请号：
GBGB2017/050162
公开号：
WO2017/125763A1
申请日:
2017.01.23
申请国别(地区):
WO
年份:
2017
代理人:
摘要：
A method and apparatus for estimating heart rate of a subject from a video image of the subject. Regions of interest are generated which avoid areas in the image of high intensity gradient (such as detectable image features) and favour areas from which higher quality signals have been obtained. One way of defining such regions of interest is by detecting and tracking feature points through the video image sequence, triangulating the feature points and generating square regions of interest corresponding to the in-circles of the triangles. Another way is by generating regions of interest according to size and location probability distributions which are defined to have a high probability for image areas away from strong intensity gradients and which generate good quality signals. The variation in intensity in each region of interest through the video sequence is taken as a time series signal, bandpass filtered in the physiologically expected range and the signals are clustered according to their similarity and spacing in the image. Signals in the same cluster are averaged together and for clusters with at least a preset number of signals, the frequency of the average signal is taken as indicating a heart rate. In an alternative embodiment, the intensity variations from the square regions of interest through the frame sequence are taken as time series signals and those signals which have a strong peak in the power spectrum are selected and subject to principal component analysis. The principal component with a highest signal quality is selected and its frequency is found and used to estimate the heart rate.La présente invention concerne un procédé et un appareil permettant destimer la fréquence cardiaque dun sujet à partir dune image vidéo du sujet. Des régions dintérêt sont générées, qui évitent dobtenir des zones dans limage de gradient dintensité élevé (telles que des éléments dimage détectables) et favorisent lobtention de zones à partir desquelles des signaux de q
