公开(公告)号：US09693710B2

公开(公告)日：2017-07-04

申请号：US14519641

申请日：2014-10-21

Applicant: Xerox Corporation

Inventor： Lalit Keshav Mestha ,  Beilei Xu ,  Survi Kyal

IPC: A61B6/00 ,  A61B5/08 ,  A61B5/00 ,  A61B5/11

CPC classification number: A61B5/0816 ,  A61B5/1128 ,  A61B5/7282 ,  A61B5/746 ,  A61B5/7485 ,  A61B2576/00

Abstract: What is disclosed is a system and method for determining respiration rate from a video of a subject. In one embodiment, a video is received comprising plurality of time-sequential image frames of a region of a subject's body. Features of pixels are extracted from that region from each image frame and vectors formed from these features. Each image frame has an associated feature vector. A N×M video matrix of the vectors of length N is constructed such that a total number of columns M in the video matrix correspond to a time duration over which the subject's respiration rate is to be determined. The video matrix is processed to obtain a matrix of eigenvectors where principal axes of variations due to motion associated with respiration are contained in a first few eigenvectors. One eigenvector is selected from the first few eigenvectors. A respiration rate is obtained from the selected eigenvector.

公开(公告)号：US09504426B2

公开(公告)日：2016-11-29

申请号：US14099358

申请日：2013-12-06

Applicant: Xerox Corporation

Inventor： Survi Kyal ,  Lalit Keshav Mestha

IPC: A61B5/00 ,  A61B5/024 ,  A61B5/113 ,  A61B5/11

CPC classification number: A61B5/7207 ,  A61B5/024 ,  A61B5/1128 ,  A61B5/1135 ,  A61B5/7203 ,  A61B5/7278 ,  A61B2576/00

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.

Abstract translation: 公开的是用于补偿从在非接触式遥感环境中对于生理功能进行监视的被摄体的视频提取的生理信号中的运动诱发伪影的系统和方法。 本方法根据从先前的视频段处理获得的生理信号来识别中心频率。 由于从一个视频段到下一个视频段的脉冲频率的瞬间变化不是非常大，可以重复处理从顺序视频段获得的信号，并且自适应带通滤波器被重新重新配置并用于过滤下一个视频段 ， 等等。 使用本文公开的教导，可以获得用于受试者的运动补偿的连续心脏信号，以经由视频成像连续监测受试者的心脏功能。 本发明的教导提供了一种在视频采集期间补偿受试者的运动的有效手段。 公开了各种实施例。

公开(公告)号：US09483837B2

公开(公告)日：2016-11-01

申请号：US14211455

申请日：2014-03-14

Applicant: Xerox Corporation

Inventor： Beilei Xu ,  Survi Kyal ,  Lalit Keshav Mestha ,  Graham S. Pennington

IPC: G06T7/20

CPC classification number: G06T7/20 ,  G06T2207/10016 ,  G06T2207/10024 ,  G06T2207/30076 ,  G06T2207/30088

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.

Abstract translation: 所公开的是用于在处理被监视的受试者的视频的处理期间补偿运动以进行生理功能评估的系统和方法。 在一个实施例中，接收图像帧。 处理N个视频帧的连续批次以分离与由摄像机登记生理信号的被摄体的身体区域相关联的像素。 处理像素以获得每个批次的时间序列信号。 确定在该批次的图像帧的视频采集期间的移动是否超过阈值水平。 如果是，则下一批图像帧的大小N被改变为：N = N + M1，其中N +M1≤Nmax。 否则，下一批次的大小N变为：N = N-M2，其中N-M2≥Nmin。 此后，当接收到下一批N个图像帧时，处理以实时连续的方式重复。 公开了各种实施例。

公开(公告)号：US09351649B2

公开(公告)日：2016-05-31

申请号：US14026739

申请日：2013-09-13

Applicant: Xerox Corporation

Inventor： Lalit Keshav Mestha ,  Survi Kyal

IPC: A61B5/024 ,  A61B5/00 ,  A61B5/021 ,  G06T7/00

CPC classification number: A61B5/02427 ,  A61B5/0075 ,  A61B5/02125 ,  G06T7/0012 ,  G06T2207/30076 ,  G06T2207/30104

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.

Abstract translation: 公开的是用于从由视频图像生成的时变源信号确定感兴趣的动脉脉冲传播时间的对象的系统和方法。 在一个实施例中，使用视频成像系统来捕获感兴趣对象的近端和远端区域的时变源信号。 处理图像帧以分离受试者暴露皮肤的近端和远端区域的局部区域。 从源视频图像中提取每个近端和远端区域的时间序列信号。 相对于每个时间序列信号的频率计算相位角，以产生每个区域的相位v / s频率曲线。 从每个相位曲线提取所选择的心脏频率范围内的斜率，并且在两个斜率之间计算差以获得对象的动脉脉冲传播时间。

公开(公告)号：US09336594B2

公开(公告)日：2016-05-10

申请号：US14200759

申请日：2014-03-07

Applicant: Xerox Corporation

Inventor： Survi Kyal ,  Lalit Keshav Mestha

IPC: G06K9/00 ,  G06T7/00 ,  A61B5/00 ,  A61B5/024

CPC classification number: G06T7/0014 ,  A61B5/0077 ,  A61B5/02416 ,  A61B5/746 ,  A61B2576/00 ,  G06T7/0012 ,  G06T7/20 ,  G06T2207/10016 ,  G06T2207/10024 ,  G06T2207/30004 ,  G06T2207/30088

Abstract: What is disclosed is a system and method for estimating cardiac pulse rate from a video of a subject being monitored for cardiac function. In one embodiment, batches of overlapping image frames are continuously received and processed by isolating regions of exposed skin. Pixels of the isolated regions are processed to obtain a time-series signal per region and a physiological signal is extracted from each region's time-series signals. The physiological signal is processed to obtain a cardiac pulse rate for each region. The cardiac pulse rate for each region is compared to a last good cardiac pulse rate from a previous batch to obtain a difference. If the difference exceeds a threshold, the cardiac pulse rate is discarded. Otherwise, it is retained. Once all the regions have been processed, the retained cardiac pulse rate with a minimum difference becomes the good cardiac pulse rate for comparison on a next iteration.

Abstract translation: 所公开的是用于从被监测用于心脏功能的受试者的视频估计心脏脉搏率的系统和方法。 在一个实施例中，通过隔离暴露皮肤的区域连续地接收并处理批次的重叠图像帧。 处理孤立区域的像素以获得每个区域的时间序列信号，并且从每个区域的时间序列信号中提取生理信号。 处理生理信号以获得每个区域的心脏脉搏率。 将每个区域的心脏脉搏率与来自前一批次的最后良好的心脏脉搏率进行比较以获得差异。 如果差异超过阈值，则丢弃心脏脉搏率。 否则保留。 一旦所有区域被处理，具有最小差异的保留的心脏脉搏率就成为良好的心脏脉搏率，用于在下一次迭代中进行比较。