时空域脉搏信号检测方法研究
发布时间：2019-03-16 13:39
【摘要】：脉搏是人体重要的生理运动,它源自心脏,影响范围波及全身。脉搏包含丰富的生理信息,是评价健康状况和诊断疾病的重要依据,具有其它生理信号无法替代的价值。桡动脉脉搏易于检测,历来是研究的热点。传统检测方法主要关注单点脉搏信号,获取信息十分有限。时空域脉搏信号是传统脉搏信号的扩展和创新,除了具有传统脉搏信号的内涵,还可反映动脉血管弹性、顺应性和血流状态等生理信息,可为传统中医对脉象的模糊性描述找到相应的量化指标和依据。总之,时空域脉搏信号具有广阔的研究前景和应用价值。本文研究工作围绕时空域脉搏信号从下列四个方面展开:(1)研制了采用双目视觉测量、具有气囊式仿指柔性探头的时空域脉搏信号检测系统。检测系统总体上为气动调节平衡状态的杠杆式结构,通过改变小型气缸内压调节探头与手腕的接触压力。探头的接触膜由丁腈材料制成,在探头内压作用下接触膜膨胀,其力学性能和触感类似手指的指腹,具有仿生性。工作状态下,接触膜随脉搏发生周期性变形,变形幅度和范围与脉搏密切相关。利用双目立体视觉测量接触膜变形状态即可获得时空域脉搏信号。(2)研究基于双目立体视觉的接触膜时空域形变测量方法。测量方法基于Marr视觉理论框架,主要分为四个步骤:相机系统标定、图像特征提取、特征匹配和空间三维坐标计算。采用张正友标定法对双相机系统进行标定。将接触膜上印制的网格状结构线交点作为特征点。传统基于灰度偏微分的特征点检测方法效果不理想,提出基于全局结构参数的图像分割方法和基于脊线的广义交点检测方法。实验证明该方法准确率高、所得交点全部位于网格线相交区域中心。建立交点矩阵数据结构,将交点坐标根据位置关系存储在矩阵当中,利用矩阵下标实现左右图像交点快速匹配。交点的位置关系则根据网格变形程度利用基于正交网格的预测算法和基于骨架线的漫延搜索算法确定。根据透镜成像原理和双目视差原理计算交点实际三维坐标,进而重构接触膜三维曲面,并从中提取时空域脉搏信号。(3)研究建立探头作用下的桡动脉脉搏有限元模型。有限元建模包括几何模型、材料模型、边界条件、载荷、分析步和单元划分等内容。根据医学影像资料和标本,对手腕解剖结构进行合理简化,建立手腕组织几何模型,探头三维几何模型与实物相同。将几何模型离散化为结构化的三维线性六面体单元。血管壁和皮肤软组织的材料模型分别采用Holzapfel和Haut等人的研究成果。对接触膜进行拉伸试验,确定二阶Mooney-Rivlin超弹性材料模型的材料常数。根据对实际系统关键因素的合理抽象设定边界条件,模型执行步骤与实际检测步骤相同。载荷包括血压、接触压力和探头内压,研究接触膜在三种载荷协同作用下的时空域变形规律。利用高精度激光位移传感器对模型进行验证和优化,仿真结果与双目立体视觉测量结果吻合。(4)基于有限元仿真结果分析时空域脉搏信号特征,发现接触膜底部总体平坦,中间有微小丘状凸起,凸起范围近似椭圆,称凸起部分为关键区域。脉搏强度越大在宏观上导致关键区域长宽比越大,在微观上导致区域中心点主曲率中的较大分量迅速变大,而较小分量变化较缓。表明中心点局部几何特征在一定程度上可替代关键区域总体几何特征描述时空域脉搏信号。建立接触膜中心点振幅与血压、接触压力和探头内压关系的非线性模型,利用多元回归分析和遗传算法获得模型参数,最终得到连续血压测量的数学模型。此外,时空域脉搏信号与中医触诊的脉搏指感原理类似,基于时空域脉搏信号提出7种中医脉象因素的量化指标,这些指标可作为脉诊客观化的工具和桥梁。
[Abstract]:The pulse is an important physiological movement of the human body, which is derived from the heart, which affects the whole body. The pulse contains abundant physiological information, is an important basis for evaluating the health status and the diagnosis of the disease, and has the value that other physiological signals can not be replaced. The pulse of the arterial artery is easy to detect, and has always been the hot spot of the study. The traditional detection method is mainly concerned with the single-point pulse signal, and the information is very limited. The time-space pulse signal is the extension and innovation of the traditional pulse signal, in addition to the connotation of the traditional pulse signal, the physiological information such as the elasticity, the compliance and the blood flow state of the arterial blood tube can be reflected, and the corresponding quantitative index and the basis can be found for the fuzzy description of the pulse image by the traditional Chinese medicine. In conclusion, the time-space pulse signal has a wide prospect and application value. In this paper, the time-domain pulse signal is expanded from the following four aspects: (1) It has developed a time-space pulse signal detection system with a binocular vision measurement and an air-bag type finger-like flexible probe. The detection system is generally a lever-type structure in which the balance state of the pneumatic regulation is adjusted, and the contact pressure between the probe and the wrist is adjusted by changing the internal pressure of the small cylinder. The contact film of the probe is made of a nitrile material, the contact film is expanded under the action of the internal pressure of the probe, and the mechanical property and the touch feel of the contact film are similar to that of a finger, and have the bionic property. In the working state, the contact film is periodically deformed with the pulse, and the amplitude and range of the deformation are closely related to the pulse. And the time-domain pulse signal can be obtained by using the binocular stereo vision to measure the deformation state of the contact film. (2) The method for measuring the spatial deformation of the contact film based on the binocular stereo vision is studied. The measurement method is based on the Marr vision theory frame, which is mainly divided into four steps: camera system calibration, image feature extraction, feature matching and spatial three-dimensional coordinate calculation. The two-camera system is calibrated by the method of Zhang Zhengyou calibration. The grid-like structure line intersection point printed on the contact film is taken as a feature point. The traditional feature point detection method based on the gray-scale partial differential is not ideal, and the image segmentation method based on the global structure parameter and the generalized intersection point detection method based on the ridge line are proposed. The experimental results show that the accuracy of the method is high, and the intersection of the obtained intersection points is located at the intersection of the grid lines. And the intersection point matrix data structure is established, and the intersection coordinates are stored in the matrix according to the position relation, and the intersection point of the left and right images is quickly matched with the matrix index. The position relation of the intersection point is determined by using the orthogonal grid-based prediction algorithm and the extension search algorithm based on the skeleton line according to the degree of the mesh deformation. According to the lens imaging principle and the binocular parallax principle, and then the three-dimensional curved surface of the contact film is reconstructed, and the space-space pulse signal is extracted from the three-dimensional surface of the contact film. (3) The finite element model of the arterial pulse under the action of the probe was studied. The finite element modeling includes geometric model, material model, boundary condition, load, analysis step and unit division. According to the medical image data and the specimen, the wrist anatomical structure is reasonably simplified, a wrist tissue geometric model is established, and the three-dimensional geometric model of the probe is the same as the physical object. The geometric model is discretized into a structured three-dimensional linear hexahedron unit. The material models of the blood vessel wall and the soft tissue of the skin were obtained by Holzapfel and Haut et al., respectively. The contact film was subjected to a tensile test to determine the material constant of the second order Mooney-Rivlin super-elastic material model. The model execution step is the same as the actual detection step according to the reasonable abstract set boundary condition for the key factor of the actual system. The load includes blood pressure, contact pressure and internal pressure of the probe. The model is verified and optimized by the high-precision laser displacement sensor, and the simulation results are in good agreement with the binocular stereo vision measurement. (4) Based on the analysis of the simulation results of the finite element, the feature of the spatial pulse signal is found. It is found that the bottom of the contact film is flat and there is a micro-shaped protrusion in the middle. The convex range is approximate to the ellipse, and the convex part is the key area. The larger the pulse intensity, the larger the aspect ratio of the critical region, the larger the larger component in the main curvature of the central point of the region in the micro-scale, and the smaller component changes. It is shown that the local geometric feature of the central point can be used to substitute the spatial pulse signal in some extent to the overall geometric feature of the key region. The nonlinear model of the relationship between the center point amplitude of the contact film and the blood pressure, the contact pressure and the internal pressure of the probe was established. The model parameters were obtained by the multiple regression analysis and the genetic algorithm, and the mathematical model of the continuous blood pressure measurement was obtained. In addition, the pulse signal of the time-domain is similar to that of the palpation of the traditional Chinese medicine, and based on the time-domain pulse signal, seven quantitative indexes of the pulse signal of the traditional Chinese medicine are put forward, and the indexes can be used as a tool and a bridge for the objective of the pulse diagnosis.
【学位授予单位】：兰州理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP391.41;R443
，
本文编号：2441478
[Abstract]:The pulse is an important physiological movement of the human body, which is derived from the heart, which affects the whole body. The pulse contains abundant physiological information, is an important basis for evaluating the health status and the diagnosis of the disease, and has the value that other physiological signals can not be replaced. The pulse of the arterial artery is easy to detect, and has always been the hot spot of the study. The traditional detection method is mainly concerned with the single-point pulse signal, and the information is very limited. The time-space pulse signal is the extension and innovation of the traditional pulse signal, in addition to the connotation of the traditional pulse signal, the physiological information such as the elasticity, the compliance and the blood flow state of the arterial blood tube can be reflected, and the corresponding quantitative index and the basis can be found for the fuzzy description of the pulse image by the traditional Chinese medicine. In conclusion, the time-space pulse signal has a wide prospect and application value. In this paper, the time-domain pulse signal is expanded from the following four aspects: (1) It has developed a time-space pulse signal detection system with a binocular vision measurement and an air-bag type finger-like flexible probe. The detection system is generally a lever-type structure in which the balance state of the pneumatic regulation is adjusted, and the contact pressure between the probe and the wrist is adjusted by changing the internal pressure of the small cylinder. The contact film of the probe is made of a nitrile material, the contact film is expanded under the action of the internal pressure of the probe, and the mechanical property and the touch feel of the contact film are similar to that of a finger, and have the bionic property. In the working state, the contact film is periodically deformed with the pulse, and the amplitude and range of the deformation are closely related to the pulse. And the time-domain pulse signal can be obtained by using the binocular stereo vision to measure the deformation state of the contact film. (2) The method for measuring the spatial deformation of the contact film based on the binocular stereo vision is studied. The measurement method is based on the Marr vision theory frame, which is mainly divided into four steps: camera system calibration, image feature extraction, feature matching and spatial three-dimensional coordinate calculation. The two-camera system is calibrated by the method of Zhang Zhengyou calibration. The grid-like structure line intersection point printed on the contact film is taken as a feature point. The traditional feature point detection method based on the gray-scale partial differential is not ideal, and the image segmentation method based on the global structure parameter and the generalized intersection point detection method based on the ridge line are proposed. The experimental results show that the accuracy of the method is high, and the intersection of the obtained intersection points is located at the intersection of the grid lines. And the intersection point matrix data structure is established, and the intersection coordinates are stored in the matrix according to the position relation, and the intersection point of the left and right images is quickly matched with the matrix index. The position relation of the intersection point is determined by using the orthogonal grid-based prediction algorithm and the extension search algorithm based on the skeleton line according to the degree of the mesh deformation. According to the lens imaging principle and the binocular parallax principle, and then the three-dimensional curved surface of the contact film is reconstructed, and the space-space pulse signal is extracted from the three-dimensional surface of the contact film. (3) The finite element model of the arterial pulse under the action of the probe was studied. The finite element modeling includes geometric model, material model, boundary condition, load, analysis step and unit division. According to the medical image data and the specimen, the wrist anatomical structure is reasonably simplified, a wrist tissue geometric model is established, and the three-dimensional geometric model of the probe is the same as the physical object. The geometric model is discretized into a structured three-dimensional linear hexahedron unit. The material models of the blood vessel wall and the soft tissue of the skin were obtained by Holzapfel and Haut et al., respectively. The contact film was subjected to a tensile test to determine the material constant of the second order Mooney-Rivlin super-elastic material model. The model execution step is the same as the actual detection step according to the reasonable abstract set boundary condition for the key factor of the actual system. The load includes blood pressure, contact pressure and internal pressure of the probe. The model is verified and optimized by the high-precision laser displacement sensor, and the simulation results are in good agreement with the binocular stereo vision measurement. (4) Based on the analysis of the simulation results of the finite element, the feature of the spatial pulse signal is found. It is found that the bottom of the contact film is flat and there is a micro-shaped protrusion in the middle. The convex range is approximate to the ellipse, and the convex part is the key area. The larger the pulse intensity, the larger the aspect ratio of the critical region, the larger the larger component in the main curvature of the central point of the region in the micro-scale, and the smaller component changes. It is shown that the local geometric feature of the central point can be used to substitute the spatial pulse signal in some extent to the overall geometric feature of the key region. The nonlinear model of the relationship between the center point amplitude of the contact film and the blood pressure, the contact pressure and the internal pressure of the probe was established. The model parameters were obtained by the multiple regression analysis and the genetic algorithm, and the mathematical model of the continuous blood pressure measurement was obtained. In addition, the pulse signal of the time-domain is similar to that of the palpation of the traditional Chinese medicine, and based on the time-domain pulse signal, seven quantitative indexes of the pulse signal of the traditional Chinese medicine are put forward, and the indexes can be used as a tool and a bridge for the objective of the pulse diagnosis.
【学位授予单位】：兰州理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP391.41;R443
，
本文编号：2441478
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