Patents by Inventor Lalit Keshav Mestha

Lalit Keshav Mestha has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20160371833
    Abstract: What is disclosed is a system and method for determining a subject's respiratory pattern from a video of that subject. One embodiment involves receiving a video comprising N?2 time-sequential image frames of a region of interest (ROI) of a subject where a signal corresponding to the subject's respiratory function can be registered by at least one imaging channel of a video imaging device. The ROI comprises P pixels. Time-series signals of duration N are generated from pixels isolated in the ROI. Features are extracted from the time-series signals and formed into P-number of M-dimensional vectors. The feature vectors are clustered into K clusters. The time-series signals corresponding to pixels represented by the feature vectors in each cluster are averaged along a temporal direction to obtain a representative signal for each cluster. One of the clusters is selected. A respiratory pattern is determined for the subject based on the representative signal.
    Type: Application
    Filed: June 17, 2015
    Publication date: December 22, 2016
    Inventors: Prathosh A. PRASAD, Lalit Keshav MESTHA, Himanshu J. MADHU
  • Patent number: 9521954
    Abstract: What is disclosed is a video system and method that accounts for differences in imaging characteristics of differing video systems used to acquire video of respective regions of interest of a subject being monitored for a desired physiological function. In one embodiment, video is captured using N video imaging devices, where N?2, of respective regions of interest of a subject being monitored for a desired physiological function (i.e., a respiratory or cardiac function). Each video imaging device is different but has complimentary imaging characteristics. A reliability factor f is determined for each of the devices in a manner more fully disclosed herein. A time-series signal is generated from each of the videos. Each time-series signal is weighted by each respective reliability factor and combined to obtain a composite signal. A physiological signal can be then extracted from the composite signal. The processed physiological signal corresponds to the desired physiological function.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: December 20, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Lalit Keshav Mestha, Survi Kyal, Himanshu J. Madhu
  • Patent number: 9523608
    Abstract: What is disclosed is a system and method for processing image data acquired using a multi-band infrared camera system with a spectral mosaic filter arranged in a geometric pattern without having to perform a demosaicing that is typical with processing data from an array of sensors. In one embodiment, image data that has been captured using a camera system that has a spectral filter mosaic comprising a plurality of spectral filters arrayed on a grid. A material index is determined, using intensity values collected by sensor elements associated with a cell's respective spectral filters. All of the material indices collectively generate a material index image. Thereafter, material identification is performed on the material index image using, for example, pixel classification. Because the demosaicing step can be effectively avoided, image processing time is reduced. The teachings hereof find their uses in a wide array of applications including automated HOV/HOT violation detection.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: December 20, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Lalit Keshav Mestha, Yao Rong Wang, Peter Paul
  • Patent number: 9521335
    Abstract: What is disclosed is a system and method for detecting febrile seizure using a thermal video camera. In one embodiment, a video is received comprising time-sequential thermal images of a subject. The video is acquired of the subject in real-time using a thermal video system. Each thermal image comprises a plurality of pixels with an intensity value of each pixel corresponding to a temperature. The thermal images are processed to determine an occurrence of a febrile seizure. The processing involves identifying a region of interest in the thermal image and determining a temperature for the region of interest based on values of the pixels isolated in that region of interest. Thereafter, a rate of change of temperatures is obtained for the subject in real-time on a per-frame basis. If the rate of change is determined to have exceeded a pre-defined threshold level, then the subject is having a febrile seizure.
    Type: Grant
    Filed: June 17, 2014
    Date of Patent: December 13, 2016
    Assignee: Xerox Corporation
    Inventors: Lalit Keshav Mestha, Beilei Xu, Rakesh Suresh Kulkarni
  • Patent number: 9514537
    Abstract: What is disclosed is a system and method for adaptively reconstructing a depth map of a scene. In one embodiment, upon receiving a mask identifying a region of interest (ROI), a processor changes either a spatial attribute of a pattern of source light projected on the scene by a light modulator which projects an undistorted pattern of light with known spatio-temporal attributes on the scene, or changes an operative resolution of a depth map reconstruction module. A sensing device detects the reflected pattern of light. A depth map of the scene is generated by the depth map reconstruction module by establishing correspondences between spatial attributes in the detected pattern and spatial attributes of the projected undistorted pattern and triangulating the correspondences to characterize differences therebetween. The depth map is such that a spatial resolution in the ROI is higher relative to a spatial resolution of locations not within the ROI.
    Type: Grant
    Filed: December 27, 2013
    Date of Patent: December 6, 2016
    Assignee: Xerox Corporation
    Inventors: Edgar A. Bernal, Wencheng Wu, Lalit Keshav Mestha
  • Patent number: 9504426
    Abstract: What is disclosed is a system and method for compensating for motion induced artifacts in physiological signals extracted from a video of a subject being monitored for a physiological function in a non-contact, remote sensing environment. The present method identifies a center frequency from a physiological signal obtained from processing a prior video segment. Since a moment to moment change in pulse frequency from one video segment to a next is not very large, signals obtained from sequential video segments can be repeatedly processed and an adaptive band-pass filter repeatedly re-configured and used to filter a next video segment, and so on. Using the teachings disclosed herein, a motion-compensated continuous cardiac signal can be obtained for the subject for continuous monitoring of the subject's cardiac function via video imaging. The teachings hereof provide an effective means for compensating for movement by the subject during video acquisition. Various embodiments are disclosed.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: November 29, 2016
    Assignee: Xerox Corporation
    Inventors: Survi Kyal, Lalit Keshav Mestha
  • Patent number: 9483837
    Abstract: What is disclosed is a system and method for compensating for motion during processing of a video of a subject being monitored for physiological function assessment. In one embodiment, image frames are received. Successive batches of N video frames are processed to isolate pixels associated with a body region of the subject where a physiological signal is registered by the camera. The pixels are processed to obtain a time-series signal for each batch. A determination is made whether movement during video acquisition of this batch of image frames exceeds a threshold level. If so then a size N of the next batch of image frames is changed to: N=N+M1, where N+M1?Nmax. Otherwise, a size N of a next batch is changed to: N=N?M2, where N?M2?Nmin. Thereafter, processing repeats in a real-time continuous manner as the next batch of the N image frames is received. Various embodiments are disclosed.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: November 1, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Survi Kyal, Lalit Keshav Mestha, Graham S. Pennington
  • Publication number: 20160287105
    Abstract: What is disclosed is a system and method for classifying a time-series signal as being ventricular premature contraction, ventricular tachycardia, or normal sinus rhythm in a patient being monitored for cardiac function assessment. One embodiment hereof involves the following. A time-series signal is received which contains frequency components that relate to the function of the subject's heart. Signal segments of interest are identified in the time-series signal. Time-domain features, frequency-domain features, and non-linear cardiac dynamics are extracted from each of the identified signal segments of interest. The extracted features and dynamics become components of at least one feature vector associated with each respective signal segment of interest. Signal segments are then classified as one of: ventricular premature contraction, ventricular tachycardia, and normal sinus rhythm, based on each signal segment's respective feature vector(s).
    Type: Application
    Filed: March 31, 2015
    Publication date: October 6, 2016
    Inventors: Luisa Fernanda POLANIA-CABRERA, Lalit Keshav MESTHA
  • Publication number: 20160287183
    Abstract: What is disclosed is a system and method for classifying a time-series signal as ventricular premature contraction in a subject being monitored for cardiac function assessment. One embodiment hereof involves first, receive a time-series signal which contains frequency components that relate to the function of the subject's heart. Signal segments of interest are identified in the time-series signal. Time-domain features comprising the peak-to-peak interval between cardiac pulses and pulse amplitudes are extracted for each signal segment of interest. The time-domain features are arranged into a two dimensional feature vector. Each feature vector is associated with a respective signal segment. A magnitude of each signal segment's respective feature vector is determined. Signal segments are classified as being ventricular premature contraction based on each segment's associated magnitude.
    Type: Application
    Filed: March 31, 2015
    Publication date: October 6, 2016
    Inventors: Luisa Fernanda POLANIA-CABRERA, Lalit Keshav MESTHA
  • Publication number: 20160287106
    Abstract: What is disclosed is a system and method for assessing risk for ventricular tachycardia from a time-series signal of a patient monitored for cardiac function assessment. One embodiment involves receiving a time-series signal which contains frequency components that relate to the function of the subject's heart. Signal segments of interest are identified in the time-series signal. Time-domain features are extracted for each signal segment of interest. The time-domain features are arranged into a two dimensional feature vector. Each feature vector is associated with a respective signal segment. A magnitude of each signal segment's respective feature vector is determined. Signal segments are classified as being ventricular premature contraction based on each segment's associated magnitude.
    Type: Application
    Filed: March 31, 2015
    Publication date: October 6, 2016
    Inventors: Lalit Keshav MESTHA, Luisa Fernanda POLANIA-CABRERA
  • Publication number: 20160283658
    Abstract: What is disclosed is a software interface tool for breast cancer screening that is designed for medical professionals to view and analyze suspicious regions for hot spots and hence facilitate a determination of whether identified areas of breast tissue are cancerous. Isotherm maps are constructed at designated temperature resolution. Maps are displayed on the screen. Point & click on the isotherm map can extract temperature values of pixels within the region covered by the isotherm contours. Also provided are isothermic views at different viewing angles which is advantageous for visual detection. Additional functionalities for hotspot selection, cropping, zooming, viewing at different angles, etc. are also enabled by the present software interface. The present software interface further utilizes a tumor detection method which is also disclosed herein.
    Type: Application
    Filed: March 25, 2015
    Publication date: September 29, 2016
    Inventors: Krithika VENKATARAMANI, Lalit Keshav MESTHA, Michael P. KEHOE, Geetha MANJUNATH
  • Patent number: 9443289
    Abstract: What is disclosed is a system for compensating for motion induced artifacts in a physiological signal obtained from multiple videos of a first and second region of interest a subject being monitored for a desired physiological function. At least one of the videos being of the first region and at least one of the videos being of the second region. The first region being at least one area of exposed skin where a desired signal corresponding to the physiological function can be registered by a video imaging device. The second region being an area where a movement by the subject is likely to induce motion artifacts into the signal. The videos are processed to isolate pixels associated with the first and second regions. Processed pixels of the isolated first regions to obtain a composite time-series signal. From the composite signal, a physiological signal corresponding to the physiological function is extracted.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: September 13, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Lalit Keshav Mestha, Survi Kyal, Himanshu J. Madhu
  • Patent number: 9436984
    Abstract: What is disclosed is a system and method for compensating for motion induce artifacts in a physiological signal obtained from a video. In one embodiment, a video of a first and second region of interest of a subject being monitored for a desired physiological function is captured by a video device. The first region is an area of exposed skin wherein a desired signal corresponding to the physiological function can be registered. The second region is an area where movement is likely to induce motion artifacts into that signal. The video is processed to isolate pixels in the image frames associated with these regions. Pixels of the first region are processed to obtain a time-series signal. A physiological signal is extracted from the time-series signal. Pixels of the second region are analyzed to identify motion. The physiological signal is processed to compensate for the identified motion.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: September 6, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Lalit Keshav Mestha, Survi Kyal, Himanshu J. Madhu
  • Patent number: 9433386
    Abstract: What is disclosed is a method for monitoring a subject for cardiac arrhythmia such as atrial fibrillation using an apparatus that can be comfortably worn by the subject around an area of exposed skin where a photoplethysmographic (PPG) signal can be registered. In one embodiment, the apparatus is a reflective or transmissive wrist-worn device with emitter/detector pairs fixed to an inner side of a band with at least one illuminator emitting source light at a specified wavelength band. The illuminator is paired to a respective photodetector comprising one or more sensors that are sensitive to a wavelength band of its paired illuminator. The photodetector measures intensity of sensed light emitted by a respective illuminator. The signal obtained by the sensors comprises a continuous PPG signal. The continuous PPG signal analyzed for peak-to-peak pulse points from which the existence of cardiac arrhythmia such as atrial fibrillation event can be determined.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: September 6, 2016
    Assignee: Xerox Corporation
    Inventors: Lalit Keshav Mestha, Survi Kyal, Barry P. Mandel, Peter Johan Nystrom
  • Patent number: 9412185
    Abstract: A method for reconstructing an image of a scene captured using a compressed sensing device. A mask is received which identifies at least one region of interest in an image of a scene. Measurements are then obtained of the scene using a compressed sensing device comprising, at least in part, a spatial light modulator configuring a plurality of spatial patterns according to a set of basis functions each having a different spatial resolution. A spatial resolution is adaptively modified according to the mask. Each pattern focuses incoming light of the scene onto a detector which samples sequential measurements of light. These measurements comprise a sequence of projection coefficients corresponding to the scene. Thereafter, an appearance of the scene is reconstructed utilizing a compressed sensing framework which reconstructs the image from the sequence of projection coefficients.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: August 9, 2016
    Assignee: Xerox Corporation
    Inventors: Edgar A. Bernal, Beilei Xu, Lalit Keshav Mestha
  • Publication number: 20160198965
    Abstract: What is disclosed is a system and method for selecting a region of interest for extracting physiological parameters from a video of a subject. In one embodiment the present method involves performing the following. First, time-series signals are received which have been generated by having processing image frames of a video of a subject captured using a single band video camera with a bandpass filter with a pass band in a wavelength range of 495-565 nm and/or 800-1000 nm. The regions of interest are areas where a plethysmographic signal can be detected by the camera. Each time-series signal is associated with a different region of interest. A signal strength is then calculated for each of the time-series signals. The region associated with the time-series signal having a highest signal strength is selected. The time-series signal associated with the selected region can be processed to extract a videoplethysmographic (VPG) signal containing physiological parameters.
    Type: Application
    Filed: January 9, 2015
    Publication date: July 14, 2016
    Inventors: Lalit Keshav MESTHA, Martin Edward HOOVER, Survi KYAL
  • Patent number: 9384554
    Abstract: What is disclosed is system and method for contemporaneously reconstructing images of a scene illuminated with unstructured and structured illumination sources. In one embodiment, the system comprises capturing a first 2D image containing energy reflected from a scene being illuminated by a structured illumination source and a second 2D image containing energy reflected from the scene being illuminated by an unstructured illumination source. A controller effectuates a manipulation of the structured and unstructured illumination sources during capture of the video. A processor is configured to execute machine readable program instructions enabling the controller to manipulate the illumination sources, and for effectuating the contemporaneous reconstruction of a 2D intensity map of the scene using the second 2D image and of a 3D surface map of the scene using the first 2D image. The reconstruction is effectuated by manipulating the illumination sources.
    Type: Grant
    Filed: September 18, 2015
    Date of Patent: July 5, 2016
    Assignee: Xerox Corporation
    Inventors: Beilei Xu, Lalit Keshav Mestha, Edgar A. Bernal
  • Patent number: 9377294
    Abstract: What is disclosed is a wireless cellular device capable of determining a volume of an object in an image captured by a camera of that apparatus. In one embodiment, the present wireless cellular device comprises an illuminator for projecting a pattern of structured light with known spatial characteristics, and a camera for capturing images of an object for which a volume is to be estimated. The camera is sensitive to a wavelength range of the projected pattern of structured light. A spatial distortion is introduced by a reflection of the projected pattern off a surface of the object. And processor executing machine readable program instructions for performing the method of: receiving an image of the object from the camera; processing the image to generate a depth map; and estimating a volume of the object from the depth map. A method for using the present wireless cellular device is also provided.
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: June 28, 2016
    Assignee: Xerox Corporation
    Inventors: Wencheng Wu, Edgar A. Bernal, Lalit Keshav Mestha, Paul R. Austin
  • Publication number: 20160156779
    Abstract: Embodiments of a system are disclosed for stress assessment of a call center agent while interacting with a customer. The system is for use with a communication network. The system includes a stress assessment device and an agent device that includes an imaging unit. The agent device is configured to capture video of a target region of exposed skin of the agent using the imaging unit, collect customer interaction data based on interaction with a customer device over the communication network, and communicate the captured video and the customer interaction data to the stress assessment device. The stress assessment device is configured to passively estimate agent stress-level based on the received video, and generate feedback to the agent based on correlation between the customer interaction data and the estimated stress-level over a predefined time interval.
    Type: Application
    Filed: February 3, 2016
    Publication date: June 2, 2016
    Inventors: Om Dadaji DESHMUKH, Nischal Murthy PIRATLA, Lalit Keshav MESTHA
  • Patent number: 9351649
    Abstract: What is disclosed is a system and method for determining a subject of interest's arterial pulse transit time from time-varying source signals generated from video images. In one embodiment, a video imaging system is used to capture a time-varying source signal of a proximal and distal region of a subject of interest. The image frames are processed to isolate localized areas of a proximal and distal region of exposed skin of the subject. A time-series signal for each of the proximal and distal regions is extracted from the source video images. A phase angle is computed with respect to frequency for each of the time-series signals to produce respective phase v/s frequency curves for each region. Slopes within a selected cardiac frequency range are extracted from each of the phase curves and a difference is computed between the two slopes to obtain an arterial pulse transit time for the subject.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: May 31, 2016
    Assignee: Xerox Corporation
    Inventors: Lalit Keshav Mestha, Survi Kyal