System and methods for video-based monitoring of vital signs
AssigneeCovidien LP
InventorsPaul S. Addison, David Foo, Dominique Jacquel
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Abstract
The present invention relates to the field of medical monitoring, and in particular non-contact, video-based monitoring of pulse rate, respiration rate, motion, and oxygen saturation. Systems and methods are described for capturing images of a patient, producing intensity signals from the images, filtering those signals to focus on a physiologic component, and measuring a vital sign from the filtered signals.
Claims21
A video-based method of measuring a patient's vital sign, comprising:
- generating a video signal from a video camera having a field of view that includes exposed skin of a patient;
- extracting from the video signal a plurality of time-varying intensity signals;
- combining two or more of the time-varying intensity signals within a region of the field of view to produce a regional intensity signal;
- transforming the regional intensity signal into the frequency domain to produce a regional frequency signal;
- accumulating peaks in the regional frequency signal over a sliding time window;
- selecting a median frequency from the accumulated peaks;
- converting the median frequency into a measured vital sign value and adding the measured vital sign value to a running average;
- and
- outputting the averaged vital sign value for further processing or display.
A video-based method of measuring a patient's vital sign, comprising:
- generating a video signal from a video camera having a field of view that includes exposed skin of a patient;
- extracting from the video signal a time-varying color signal for each of a plurality of pixels in the field of view;
- identifying a frequency content of each color signal;
- combining color signals within a region of the field of view;
- measuring said vital sign from the combined color signal, including over a period of time, accumulating frequency peaks from the combined signal, selecting a median frequency and updating a running average vital sign value of a patient by converting the median frequency into a measured vital sign value and adding the measured vital sign value to the running average, wherein accumulating frequency peaks comprises cross-correlating the frequency spectrum of each color signal to amplify results;
- and
- outputting the updated average vital sign value for further processing or display.
A video-based method of measuring a patient's vital sign, comprising:
- generating a video signal from a video camera having a field of view that includes exposed skin of a patient;
- extracting from the video signal a time-varying color signal for each of a plurality of pixels in the field of view;
- identifying a frequency content of each color signal;
- combining color signals within a region of the field of view;
- measuring said vital sign from the combined color signal, including over a period of time, accumulating frequency peaks from the combined signal, selecting a median frequency and updating a running average vital sign value of a patient by converting the median frequency into a measured vital sign value and adding the measured vital sign value to the running average, wherein accumulating frequency peaks comprises adding frequencies multiple times based on a peak's relative height, with harmonics of already added frequencies only added once;
- and
- outputting the updated average vital sign value for further processing or display.
Dependencies are inferred from the claim text.