University System of Maryland

National Institutes of Health, a Component of the US Dept. of Health & Human Services

Dolby Laboratories Licensing Corporation

North Carolina State University

Qiang Zhu

Min Wu

Chau-Wai Wong

Mingliang Chen

Guan-Ming Su

Qing Song

Neeraj J Gadgil

Xin Tian

Quanzeng Wang

Zachary Lazri

Chang-Hong Fu

Jiahao Su

An apparatus for vital sign extraction. The apparatus may receive a vital signal of a subject from a sensing device. The apparatus may also perform a preprocessing procedure on the vital signal via bandpass filtering and normalization to obtain a preprocessed signal. The apparatus may also perform a time-frequency analysis of the preprocessed signal, and estimate a heart rate of the subject from a dominant component of the preprocessed signal by finding location of a maximum spectral energy of the time-frequency analysis. In addition, the apparatus may identify guard components in the preprocessed signal in view of the dominant component, and derive a respiratory rate of the subject from a length of an interval between the dominant component and each of the guard components.

Modulation model of photoplethysmography signal for vital sign extraction

Systems, methods, apparatuses, and computer program for reconstructing electrocardiogram (ECG) waveforms from photoplethysmogram (PPG). A method for cardiovascular monitoring and analytics may include obtaining an electrical signal of a heart. The method may also include obtaining a circulatory signal related to a pulsatile volume of blood in tissue. The method may also include preprocessing the electrical signal and the circulatory signal. The method may further include training a mapping using the preprocessed electrical signal and circulatory signal. In addition, the method may include deriving cardiovascular data based on the trained mapping of the preprocessed electrical signal or circulatory signal.

Electrocardiogram waveform reconstruction from photoplethysmogram

Systems, methods, apparatuses, and computer program products for contact-free heart rate monitoring and/or measurement are provided. One method may include receiving video(s) that include visual frame(s) of individual(s) performing exercises, detecting some exposed skin from the video(s), and performing motion compensation to generate color signals for the exposed skin to precisely align frames of the exposed skin. The method may also include generating the color signals by estimating a skin color for each frame by taking a spatial average over pixels of a cheek of the face(s) for R, G, and B channels, respectively, applying an operation to remove remaining motion traces from the frames such that the heart rate traces dominate, and extracting and/or outputting the heart rate of the individuals using a frequency estimator of the skin color signals.

System and method for heart rate measurement using facial video

Systems, methods, apparatuses, and computer program products for tracking weak signal traces under severe noise and/or distortions. A method may include tracking at least one candidate frequency trace from a time-frequency representation of a signal. The method may also include identifying a frequency trace of the signal based on tracking results. In addition, the method may include outputting an estimated frequency vector related to the frequency trace. Further, the tracking may be performed under a noisy condition environment.

Methods and apparatuses for implementing adaptive multi-trace carving to track signal traces

Systems, methods, apparatuses, and computer program products for contact-free heart rate monitoring and/or measurement are provided. One method may include receiving video(s) that include visual frame(s) of individual s) performing exercises, detecting some exposed skin from the video(s), and performing motion compensation to generate color signals for the exposed skin to precisely align frames of the exposed skin. The method may also include generating the color signals by estimating a skin color for each frame by taking a spatial average over pixels of a cheek of the face(s) for R, G, and B channels, respectively, applying an operation to remove remaining motion traces from the frames such that the heart rate traces dominate, and extracting and/or outputting the heart rate of the individuals using a frequency estimator of the skin color signals.

Heart rate measurement using video

Methods and systems for reducing banding artifacts when displaying high-dynamic-range images are described. Given an input image in a first dynamic range, and an input backward reshaping function mapping codewords from the first dynamic range to a second dynamic range, wherein the second dynamic range is equal or higher than the first dynamic range, statistical data based on the input image and the input backward reshaping function are generated to estimate the risk of banding artifacts in a target image in the second dynamic range generated by applying the input backward reshaping function to the input image. Separate banding alleviation algorithms are applied in the darks and highlights parts of the first dynamic range to generate a modified backward reshaping function, which when applied to the input image to generate the target image eliminates or reduces banding in the target image.

Growing community of inventors

College Park, MD, United States of America

Qiang Zhu