公开(公告)号：US20140378842A1

公开(公告)日：2014-12-25

申请号：US13921939

申请日：2013-06-19

Applicant: Xerox Corporation

Inventor： Beilei XU ,  Lalit Keshav MESTHA ,  Survi KYAL ,  Himanshu J. MADHU

IPC: A61B5/00

CPC classification number: A61B5/0077 ,  A61B5/0205 ,  A61B5/7221 ,  A61B5/7278 ,  A61B2562/04 ,  A61B2576/00

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.

Abstract translation: 公开的是一种视频系统和方法，其考虑了用于获取正在被监视的期望生理功能的被摄体的感兴趣区域的视频的不同视频系统的成像特征的差异。 在一个实施例中，使用N个视频成像装置捕获视频，其中N≥2个被监测的对象的各个感兴趣区域用于期望的生理功能（即，呼吸或心脏功能）。 每个视频成像设备是不同的，但具有互补的成像特征。 以这里更全面地公开的方式为每个设备确定可靠性因子f。 从每个视频产生时间序列信号。 每个时间序列信号由每个相应的可靠性因子加权并组合以获得复合信号。 然后可以从复合信号中提取生理信号。 经处理的生理信号对应于所需的生理功能。

公开(公告)号：US20160106378A1

公开(公告)日：2016-04-21

申请号：US14519607

申请日：2014-10-21

Applicant: XEROX CORPORATION

Inventor： Survi KYAL ,  Lalit Keshav MESTHA ,  Beilei XU

IPC: A61B5/00 ,  A61B5/11 ,  A61B8/02 ,  A61B5/0476 ,  A61B5/0488 ,  A61B7/00 ,  A61B5/0402 ,  A61B5/0205

CPC classification number: A61B5/7282 ,  A61B5/0022 ,  A61B5/02405 ,  A61B5/02416 ,  A61B5/04014 ,  A61B5/04015 ,  A61B5/0456 ,  A61B5/1102 ,  A61B5/1128 ,  A61B5/7267 ,  A61B5/747 ,  A61B8/02

Abstract: What is disclosed is a system and method for detecting an arrhythmic or non-arrhythmic event from a cardiac signal obtained from a subject. In one embodiment, a plurality of different cardiac signals are received and are transformed into frequency domain signals which, in turn, are changed such that a dominant frequency in each of the signals is substantially aligned to form a matrix of feature vectors. The feature matrix is used to train a classifier. A cardiac signal from the subject is received and transformed to a frequency domain signal. The frequency domain signal is changed such that a dominant is substantially aligned with a dominant frequency of signals used to train the classifier. The subject's frequency domain signal is provided as a new feature vector to the classifier. The classifier uses the new feature vector to classify the subject as having an arrhythmic or a non-arrhythmic event.

Abstract translation: 公开的是用于从从受试者获得的心脏信号中检测心律失常或非心律不齐事件的系统和方法。 在一个实施例中，接收多个不同的心脏信号并将其变换成频域信号，频域信号又被改变，使得每个信号中的主要频率基本对准以形成特征向量的矩阵。 特征矩阵用于训练分类器。 来自受试者的心脏信号被接收并变换为频域信号。 改变频域信号，使得显性基本上与用于训练分类器的信号的主频对齐。 被摄体的频域信号作为新特征向量提供给分类器。 分类器使用新的特征向量将主体分类为具有心律失常或非心律失常事件。

公开(公告)号：US20160081566A1

公开(公告)日：2016-03-24

申请号：US14492948

申请日：2014-09-22

Applicant: Xerox Corporation

Inventor： Beilei XU ,  Survi KYAL ,  Lalit Keshav MESTHA

IPC: A61B5/024 ,  A61B5/00 ,  A61B5/11 ,  A61B5/0476 ,  A61B8/02 ,  A61B5/0464 ,  A61B7/02 ,  A61B5/04 ,  A61B5/044 ,  A61B5/02 ,  A61B5/0456 ,  A61B5/046 ,  A61B5/0245 ,  A61B5/0488

CPC classification number: A61B5/02405 ,  A61B5/0006 ,  A61B5/02028 ,  A61B5/024 ,  A61B5/02416 ,  A61B5/0245 ,  A61B5/04012 ,  A61B5/044 ,  A61B5/0452 ,  A61B5/0456 ,  A61B5/046 ,  A61B5/0464 ,  A61B5/0476 ,  A61B5/0488 ,  A61B5/1102 ,  A61B5/6898 ,  A61B5/7264 ,  A61B5/746 ,  A61B5/747 ,  A61B7/02 ,  A61B8/02 ,  A61B2560/0475

Abstract: What is disclosed is a system and method identifying a type of cardiac event from cardiac signals obtained from a subject. In one embodiment, at least two clusters are formed. Each cluster is associated with a different cardiac event based on features of interest identified from various cardiac signal segments. At least one of the clusters is associated with a cardiac event which is an arrhythmia and one of the clusters is associated with a non-arrhythmia. A new cardiac signal segment of a subject is received. The signal segment is analyzed to identify features of interest. A distance is calculated between each of the clusters and the identified features of interest obtained from having analyzed the subject's cardiac signal segment. A cardiac event is identified for the subject based on the type of cardiac event associated with the cluster which the subject's features of interest had a shortest distance to.

Abstract translation: 公开的是从从受试者获得的心脏信号识别心脏事件的类型的系统和方法。 在一个实施例中，形成至少两个簇。 基于从各种心脏信号段识别的兴趣特征，每个群集与不同的心脏事件相关联。 至少一个簇与心脏事件相关联，心脏事件是心律不齐，其中一个簇与非心律失常相关联。 接收受试者的新的心脏信号段。 分析信号段以识别感兴趣的特征。 在每个聚类之间计算距离，并且从已经分析了受试者的心脏信号片段获得的所识别的关注特征被计算。 基于与集群相关联的心脏事件的类型来识别受试者的心脏事件，该受试者的兴趣特征具有最短的距离。

公开(公告)号：US20150332457A1

公开(公告)日：2015-11-19

申请号：US14281072

申请日：2014-05-19

Applicant: XEROX CORPORATION

Inventor： Lalit Keshav MESTHA ,  Survi KYAL ,  Beilei XU

IPC: G06T7/00 ,  G06K9/20 ,  G06K9/00

CPC classification number: G06T7/0016 ,  A61B5/0077 ,  G06K9/00362 ,  G06K9/0053 ,  G06K9/0055 ,  G06K9/2018 ,  G06K2009/00939 ,  G06T7/254 ,  G06T2207/10016 ,  G06T2207/10024 ,  G06T2207/10048 ,  G06T2207/30004 ,  G06T2207/30076

Abstract: What is disclosed is a system and method for increasing the accuracy of physiological signals obtained from video of a subject being monitored for a desired physiological function. In one embodiment, image frames of a video are received. Successive batches of image frames are processed. For each batch, pixels associated with an exposed body region of the subject are isolated and processed to obtain a time-series signal. If movement occurred during capture of these image frames that is below a pre-defined threshold level then parameters of a predictive model are updated using this batch's time-series signal. Otherwise, the last updated predictive model is used to generate a predicted time-series signal for this batch. The time-series signal is fused with the predicted time-series signal to obtain a fused time-series signal. The time-series signal for each batch is processed to obtain a physiological signal for the subject corresponding to the physiological function.

Abstract translation: 所公开的是用于增加从所监视的受试者的视频获得的生理信号的准确性的系统和方法，用于期望的生理功能。 在一个实施例中，接收视频的图像帧。 处理连续批量的图像帧。 对于每个批次，与对象的暴露的身体区域相关联的像素被隔离并被处理以获得时间序列信号。 如果在捕获低于预定阈值水平的图像帧的情况下发生移动，则使用该批次的时间序列信号来更新预测模型的参数。 否则，最后更新的预测模型用于生成该批次的预测时间序列信号。 时间序列信号与预测的时间序列信号融合以获得融合的时间序列信号。 处理每个批次的时间序列信号以获得与生理功能相对应的对象的生理信号。

公开(公告)号：US20150313486A1

公开(公告)日：2015-11-05

申请号：US14596344

申请日：2015-01-14

Applicant: Xerox Corporation

Inventor： Lalit Keshav MESTHA ,  Survi KYAL

IPC: A61B5/024 ,  A61B5/00 ,  A61B5/0285 ,  A61B5/02 ,  A61B5/0456 ,  A61B5/021

CPC classification number: A61B5/0456 ,  A61B5/02007 ,  A61B5/02125 ,  A61B5/02416 ,  A61B5/02427 ,  A61B5/0285 ,  A61B5/7225 ,  A61B5/7289

Abstract: What is disclosed is a system and method for determining a pulse transit time for a subject. In one embodiment, the system comprises a handheld wireless cellular device configured with a sensor to acquire an electrocardiogram (ECG) signal from the subject and a photodetector generating a time-series signal in response to continuously sensing a reflection of source light off a region of exposed skin of the subject where a photoplethysmographic (PPG) signal can be detected by the photodetector. In one embodiment, the time-series signal is a PPG signal. In another embodiment, the time-series signal is processed to extract a PPG signal. A temporally overlapping segment of the PPG and ECG signals is analyzed to obtain a pulse transit time between a reference point on the PPG signal and a reference point on the ECG signal. The pulse transit time is used to assess pathologic conditions such as peripheral vascular disease.

Abstract translation: 公开的是用于确定对象的脉冲传播时间的系统和方法。 在一个实施例中，该系统包括手持式无线蜂窝设备，其被配置有传感器以从对象获取心电图（ECG）信号;以及光电检测器，响应于连续感测源光源的反射而产生时间序列信号 可以通过光电检测器检测光电体积描记术（PPG）信号的受试者的暴露皮肤。 在一个实施例中，时间序列信号是PPG信号。 在另一个实施例中，处理时间序列信号以提取PPG信号。 分析PPG和ECG信号的时间上重叠的段以获得PPG信号上的参考点和ECG信号上的参考点之间的脉冲传播时间。 脉冲传播时间用于评估外周血管疾病等病理状况。

公开(公告)号：US20160106340A1

公开(公告)日：2016-04-21

申请号：US14519641

申请日：2014-10-21

Applicant: Xerox Corporation

Inventor： Lalit Keshav MESTHA ,  Beilei XU ,  Survi KYAL

IPC: A61B5/08 ,  A61B5/00

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.

Abstract translation: 公开的是用于从受试者的视频确定呼吸率的系统和方法。 在一个实施例中，接收包括被摄体的区域的多个时序图像帧的视频。 从每个图像帧的区域提取像素的特征，并从这些特征形成的矢量。 每个图像帧具有相关联的特征向量。 长度为N的矢量的N×M视频矩阵被构造成使得视频矩阵中的列M的总数对应于要确定被摄体的呼吸速率的持续时间。 处理视频矩阵以获得特征向量矩阵，其中由于与呼吸相关联的运动引起的变化的主轴包含在前几个特征向量中。 从前几个特征向量中选择一个特征向量。 从所选择的特征向量获得呼吸速率。

公开(公告)号：US20160106328A1

公开(公告)日：2016-04-21

申请号：US14515618

申请日：2014-10-16

Applicant: Xerox Corporation

Inventor： Lalit Keshav MESTHA ,  Survi KYAL

IPC: A61B5/021 ,  A61B5/0295 ,  A61B5/02 ,  A61B5/026 ,  A61B5/00

CPC classification number: A61B5/02125 ,  A61B5/02416 ,  A61B5/0295 ,  A61B5/1128 ,  A61B5/7253 ,  A61B5/7282

Abstract: What is disclosed is a system and method for determining arterial pulse transit time (PTT) for a subject. In one embodiment, time-series signals are received for each of a proximal and distal arterial site of a subject's body which represent blood volume changes in the microvascular tissue at each site. A proximal and distal analytic signal is obtained which has a first component being a waveform of the respective time-series signal and a second component being a transform of the respective waveform. A phase function is determined for the first and second components of each analytic signal. The phase function obtained for the proximal waveform is then subtracted from the phase function obtained for the distal waveform to get a phase difference. The phase difference is analyzed with the subject's heart rate to determine an arterial pulse wave transit time between the two proximal and distal sites.

Abstract translation: 公开的是用于确定受试者的动脉脉搏传播时间（PTT）的系统和方法。 在一个实施例中，针对受试者身体的近端和远端动脉部位的每一个接收时间序列信号，其表示每个部位的微血管组织中的血液体积变化。 获得近端和远端分析信号，其具有第一分量是相应时间序列信号的波形，第二分量是相应波形的变换。 确定每个分析信号的第一和第二分量的相位函数。 然后从为远端波形获得的相位函数中减去近端波形获得的相位函数以获得相位差。 用受试者的心率分析相位差，以确定两个近端和远端部位之间的动脉脉搏波传播时间。

公开(公告)号：US20150250391A1

公开(公告)日：2015-09-10

申请号：US14200759

申请日：2014-03-07

Applicant: XEROX CORPORATION

Inventor： Survi KYAL ,  Lalit Keshav MESTHA

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

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。

公开(公告)号：US20140012142A1

公开(公告)日：2014-01-09

申请号：US14026739

申请日：2013-09-13

Applicant: Xerox Corporation

Inventor： Lalit Keshav MESTHA ,  Survi KYAL

IPC: A61B5/024

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：US20130342670A1

公开(公告)日：2013-12-26

申请号：US13871728

申请日：2013-04-26

Applicant: XEROX CORPORATION

Inventor： Survi KYAL ,  Lalit Keshav MESTHA ,  Beilei XU

IPC: A61B5/00

CPC classification number: A61B5/7225 ,  A61B5/0013 ,  A61B5/0077 ,  A61B5/02416 ,  A61B5/7203 ,  A61B5/7278 ,  G06F19/00 ,  G06K9/00496 ,  G06T7/0016 ,  G06T2207/30004 ,  G06T2207/30076 ,  G16H40/67

Abstract: What is disclosed is a novel system and method for extracting photoplethysmographic (PPG) signals (i.e., cardiac signals) on a continuous basis from signals generated from video images captured of a subject being monitored for cardiac function in a non-contact remote sensing environment. In one embodiment, a time-series signal is received. The time-series signal is generated from video images captured of a region of exposed skin where a PPG signal of a subject of interest can be registered. The time-series signal is then divided into batches for processing, with successive batches having at least a 95% overlap with a previous batch. Each of the batches of time-series signals is processed to obtain a PPG signal from each batch. A mid-point of each of these PPG-signals is stitched together to obtain a continuous PPG signal for the subject. The continuous PPG signal for the subject can then viewed on a display device.

Abstract translation: 所公开的是一种用于从非接触式遥感环境中心脏功能监测对象被捕获的视频图像产生的信号连续提取光电体积描记术（PPG）信号（即心脏信号）的新型系统和方法。 在一个实施例中，接收时间序列信号。 时间序列信号是从可以登记感兴趣对象的PPG信号的暴露皮肤区域拍摄的视频图像产生的。 然后将时间序列信号分成批次进行处理，其中连续批次与先前批次具有至少95％的重叠。 处理每批批次的时间序列信号以从每个批次获得PPG信号。 将这些PPG信号的每一个的中点缝合在一起以获得对象的连续的PPG信号。 然后可以在显示设备上观看被摄体的连续PPG信号。