公开(公告)号：US20110313274A1

公开(公告)日：2011-12-22

申请号：US12924959

申请日：2010-10-09

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： A61B5/055

CPC分类号： A61B5/05 ,  A61B5/04007 ,  A61B5/04008 ,  A61B5/7257

摘要： This invention discloses methods and apparatuses for 3D imaging in Magnetoencephalography (MEG), Magnetocardiography (MCG), and electrical activity in any biological tissue such as neural/muscle tissue. This invention is based on Field Paradigm founded on the principle that the field intensity distribution in a 3D volume space uniquely determines the 3D density distribution of the field emission source and vice versa. Electrical neural/muscle activity in any biological tissue results in an electrical current pattern that produces a magnetic field. This magnetic field is measured in a 3D volume space that extends in all directions including substantially along the radial direction from the center of the object being imaged. Further, magnetic field intensity is measured at each point along three mutually perpendicular directions. This measured data captures all the available information and facilitates a computationally efficient closed-form solution to the 3D image reconstruction problem without the use of heuristic assumptions. This is unlike prior art where measurements are made only on a surface at a nearly constant radial distance from the center of the target object, and along a single direction. Therefore necessary, useful, and available data is ignored and not measured in prior art. Consequently, prior art does not provide a closed-form solution to the 3D image reconstruction problem and it uses heuristic assumptions. The methods and apparatuses of the present invention reconstruct a 3D image of the neural/muscle electrical current pattern in MEG, MCG, and related areas, by processing image data in either the original spatial domain or the Fourier domain.

摘要翻译： 本发明公开了脑电图（MEG），心电图（MCG）中的3D成像和任何生物组织如神经/肌肉组织中的电活动的方法和装置。 本发明基于场范式，其基于3D体积空间中的场强分布唯一地确定场发射源的3D密度分布的原理，反之亦然。 任何生物组织中的电神经/肌肉活动导致产生磁场的电流模式。 该磁场是在3D体积空间中测量的，该3D体积空间在所有方向上延伸，包括基本上沿着被成像物体的中心的径向方向。 此外，在沿着三个相互垂直的方向的每个点处测量磁场强度。 该测量数据捕获所有可用的信息，并且有助于在不使用启发式假设的情况下对3D图像重建问题进行计算上有效的闭式解决方案。 这与现有技术不同，现有技术仅在距离目标物体的中心几乎恒定的一个表面上沿着单个方向进行测量。 因此，必要的，有用的和可用的数据被忽略，而不是在现有技术中测量。 因此，现有技术不提供3D图像重建问题的闭合形式解决方案，并且它使用启发式假设。 本发明的方法和装置通过处理原始空间域或傅立叶域中的图像数据来重建MEG，MCG和相关区域中的神经/肌肉电流模式的3D图像。

公开(公告)号：US5148209A

公开(公告)日：1992-09-15

申请号：US551933

申请日：1990-07-12

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01C3/06 ,  G02B7/36 ,  G03B13/36 ,  G06T1/00 ,  H04N5/232

CPC分类号： G02B7/36

摘要： Apparatus and methods based on signal processing techniques are disclosed for determining the distance of an object from a camera, rapid autofocusing of a camera, and obtaining focused pictures from blurred pictures produced by a camera. The apparatus of the present invention includes a camera characterized by a set of four camera parameters: position of the image detector or film inside the camera, focal length of the optical system in the camera, the size of the aperture of the camera, and the characteristics of the light filter in the camera. In the method of the present invention, at least two images of the object are recorded with different values for the set of camera parameters. The two images are converted to a standard format to obtain two normalized images. The values of the camera parameters and the normalized images are substituted into an equation obtained by equating two expressions for the focused image of the object. The two expressions for the focused image are based on a new deconvolution formula which requires computing only the derivatives of the normalized images and a set of weight parameters dependent on the camera parameters and the point spread function of the camera. In particular, the deconvolution formula does not involve any Fourier transforms and therefore the present invention has significant advantages over prior art. The equation which results from equating two expressions for the focused image of the object is solved to obtain a set of solutions for the distance of the object. A third image of the object is then recorded with new values for the set of camera parameters. The solution for distance which is consistent with the third image and the new values for the camera parameters is determined to obtain the distance of the object. Based on the distance of the object, a set of values is determined for the camera parameters for focusing the object. The camera parameters are then set equal to these values to accomplish autofocusing. After determining the distance of the object, the focused image of the object is obtained using the deconvolution formula. A generalized version of the method of determining the distance of an object can be used to determine one or more unknown camera parameters. This generalized version is also applicable to any linear shift-invariant system for system parameter estimation and signal restoration.

公开(公告)号：US20140354278A1

公开(公告)日：2014-12-04

申请号：US13986728

申请日：2013-05-29

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01R33/56

CPC分类号： G01R33/445 ,  G01R33/326

摘要： Apparatus for measuring magnetic field intensity characteristics around a target object enclosed in a 3D volume space is disclosed. It comprises (a) a means for magnetically polarizing the target object with a known polarizing magnetic field to introduce a magnetic density distribution (MDI) f(r1), (b) a means for measuring magnetic field characteristics g(r2) around the target object at a set of points r2 in a 3D volume space that in particular extends substantially along a radial direction pointing away from the approximate center of the object, (c) a means for setting up a vector-matrix equation; and (d) a means for solving this vector-matrix equation and obtaining a solution for f(r1) that provides a 3D tomographic image of the target object. This novel apparatus is integrated with frequency and phase encoding methods of Magnetic Resonance Imaging (MRI) technique in prior art to achieve different trade-offs.

摘要翻译： 公开了用于测量围绕在3D体积空间中的目标物体周围的磁场强度特性的装置。 它包括：（a）用已知的偏振磁场对目标物体进行磁极化以引入磁密度分布（MDI）f（r1）的装置，（b）用于测量围绕目标的磁场特性g（r2）的装置 在3D体积空间中的一组点r2上的对象，其特别地基本上沿着指向物体的近似中心的径向方向延伸，（c）用于设置向量矩阵方程的装置; 和（d）用于求解该向量矩阵方程并获得提供目标对象的3D断层图像的f（r1）的解的方法。 这种新颖的装置与现有技术中的磁共振成像（MRI）技术的频率和相位编码方法相结合，以实现不同的权衡。

公开(公告)号：US08456164B2

公开(公告)日：2013-06-04

申请号：US12927653

申请日：2010-11-20

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01V3/14 ,  G01R33/48

CPC分类号： G01R33/445 ,  G01R33/448 ,  G01R33/48 ,  G01R33/5616

摘要： Three-dimensional (3D) tomographic image of a target object such as soft-tissue in humans is obtained in the method and apparatus of the present invention. The target object is first magnetized by a polarizing magnetic field pulse. The magnetization of the object is specified by a 3D spatial Magnetic Density image (MDI). The magnetic field due to the magnetized Object is measured in a 3D volume space that extends in all directions Including substantially along the radial direction, not just on a surface as in prior art. This measured data includes additional information overlooked in prior art and this data is processed to obtain a more accurate 3 D image reconstruction in lesser time than in prior art. The methods and apparatuses of the present invention are combined with frequency and phase encoding techniques of Magnetic Resonance imaging (MRI) technique in prior art to achieve different trade-offs.

摘要翻译： 在本发明的方法和装置中获得人类中的诸如软组织的目标物体的三维（3D）断层图像。 目标物体首先被偏振磁场脉冲磁化。 物体的磁化由3D空间磁密度图像（MDI）指定。 在现有技术中，由磁化物体产生的磁场是在三维体积空间中测量的，该三维体积空间在所有方向上延伸，包括基本上沿着径向方向，而不仅仅是在表面上。 该测量数据包括现有技术中忽略的附加信息，并且该数据被处理以在比现有技术更短的时间内获得更准确的3D图像重建。 将本发明的方法和装置与现有技术中的磁共振成像（MRI）技术的频率和相位编码技术相结合，以实现不同的权衡。

公开(公告)号：US08378682B2

公开(公告)日：2013-02-19

申请号：US12658001

申请日：2010-02-01

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01V3/00

CPC分类号： G01R33/48 ,  G01R33/3415 ,  G01R33/481

摘要： Field Image Tomography (FIT) is a fundamental new theory for determining the three-dimensional (3D) spatial density distribution of field emitting sources. The field can be the intensity of any type of field including (i) Radio Frequency (RF) waves in Magnetic Resonance Imaging (MRI), (ii) Gamma radiation in SPECT/PET, and (iii) gravitational field of earth, moon, etc. FIT exploits the property that field intensity decreases with increasing radial distance from the field source and the field intensity distribution measured in an extended 3D volume space can be used to determine the 3D spatial density distribution of the emitting source elements. A method and apparatus are disclosed for MRI of target objects based on FIT. Spinning atomic nuclei of a target object in a magnetic field are excited by beaming a suitable Radio Frequency (RF) pulse. These excited nuclei emit RF radiation while returning to their normal state. The intensity or amplitude distribution of the RF emission field g is measured in a 3D volume space that may extend substantially along the radial direction around the emission source. g is related to the 3D tomography f through a system matrix H that depends on the MRI apparatus, and noise n through the vector equation g=Hf+n. This equation is solved to obtain the tomographic image f of the target object by a method that reduces the effect of noise.

摘要翻译： 场图像断层扫描（FIT）是确定场发射源的三维（3D）空间密度分布的基本新理论。 该领域可以是任何类型的场的强度，包括（i）磁共振成像（MRI）中的射频（RF）波，（ii）SPECT / PET中的伽马辐射，以及（iii）地球，月亮的重力场， FIT利用场强随距离场源的径向距离的增加而减小的属性，并且可以使用在扩展3D体积空间中测量的场强分布来确定发射源元件的3D空间密度分布。 公开了一种基于FIT的目标物体的MRI的方法和装置。 通过射出合适的射频（RF）脉冲来激发目标物体在磁场中的旋转原子核。 这些激发的核在返回正常状态时发射RF辐射。 RF发射场g的强度或振幅分布在可以沿着围绕发射源的径向方向延伸的3D体积空间中测量。 g通过依赖于MRI装置的系统矩阵H和通过矢量方程g = Hf + n的噪声n与3D断层摄影f有关。 通过减少噪声影响的方法解决该等式以获得目标对象的断层图像f。

公开(公告)号：US5231443A

公开(公告)日：1993-07-27

申请号：US807983

申请日：1991-12-16

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G02B7/28 ,  G02B7/38

CPC分类号： G02B7/38 ,  G02B7/28 ,  H04N13/0235 ,  H04N13/0271

摘要： A method based on image defocus information is disclosed for determining distance (or ranging) of objects from a camera system and autofocusing of camera systems. The method uses signal processing techniques. The present invention includes a camera characterized by a set of four camera parameters: position of the image detector inside the camera, focal length of the optical system in the camera, the size of the aperture of the camera, and the characteristics of the light filter in the camera. In the method of the present invention, at least two images of the object are recorded with different values for the set of camera parameters. The two images are converted to one-dimensional signals by summing them along a particular direction whereby the effect of noise is reduced and the amount of computations are significantly reduced. Fourier coefficients of the one-dimensional signals and a log-by-rho-squared transform are used to obtain a calculated table. A stored table is calculated using the log-by-rho-squared transform and the Modulation Transfer Function of the camera system. Based on the calculated table and the stored table, the distance of the desired object is determined. In autofocusing, the calculated table and the stored table are used to calculate a set of focus camera parameters. The camera system is then set to the focus camera parameters to accomplish autofocusing.

摘要翻译： 公开了一种基于图像散焦信息的方法，用于确定来自相机系统的物体的距离（或距离）以及相机系统的自动对焦。 该方法使用信号处理技术。 本发明包括一个相机，其特征在于一组四个相机参数：图像检测器在相机内的位置，相机中光学系统的焦距，相机的孔径尺寸以及光滤波器的特性 在相机中。 在本发明的方法中，对于该组相机参数，记录有不同的对象的至少两个图像。 这两个图像通过沿着特定方向相加而被转换为一维信号，从而降低了噪声的影响并且显着减少了计算量。 使用一维信号的傅里叶系数和对数平方变换来获得计算表。 使用相机系统的对数平方变换和调制传递函数计算存储的表。 根据计算出的表和存储的表，确定所需对象的距离。 在自动对焦中，计算表和存储表用于计算一组对焦相机参数。 然后将相机系统设置为对焦相机参数以完成自动对焦。

公开(公告)号：US20120221617A1

公开(公告)日：2012-08-30

申请号：US13136566

申请日：2011-08-04

申请人： Muralidhara Subbarao ,  Shekhar Bangalore Sastry ,  Satyaki Dutta

发明人： Muralidhara Subbarao ,  Shekhar Bangalore Sastry ,  Satyaki Dutta

IPC分类号： G06F17/11 ,  G06F17/14 ,  G06F17/16 ,  G06F1/02

CPC分类号： G06F17/16 ,  G06F17/13

摘要： A method of fast matrix multiplication and a method and apparatus for fast solving of a matrix equation are disclosed. They are useful in many applications including image blurring, deblurring, and 3D image reconstruction, in 3D microscopy and computer vision. The methods and apparatus are based on a new theoretical result—the Generalized Convolution Theorem (GCT). Based on GCT, matrix equations that represent certain linear integral equations are first transformed to equivalent convolution integral equations through change of variables. Then the resulting convolution integral equations are evaluated or solved using the Fast Fourier Transform (FFT). Evaluating a convolution integral corresponds to matrix multiplication and solving a convolution integral equation corresponds to solving the related matrix equation through deconvolution. Carrying-out these convolution and deconvolution operations in the Fourier domain using FFT speeds up computations significantly. These results are applicable to both one-dimensional and multi-dimensional integral equations.

摘要翻译： 公开了一种快速矩阵乘法的方法和用于快速求解矩阵方程的方法和装置。 它们在许多应用中是有用的，包括3D显微镜和计算机视觉中的图像模糊，去模糊和3D图像重建。 方法和装置基于新的理论结果 - 广义卷积定理（GCT）。 基于GCT，表示某些线性积分方程的矩阵方程首先通过变量变换转换为等效卷积积分方程。 然后使用快速傅立叶变换（FFT）来评估或求解所得到的卷积积分方程。 评估卷积积分对应于矩阵乘法，并求解卷积积分方程对应于通过去卷积求解相关矩阵方程。 使用FFT在傅立叶域中进行这些卷积和去卷积运算，显着加快了计算。 这些结果适用于一维和多维积分方程。

公开(公告)号：US20110073763A1

公开(公告)日：2011-03-31

申请号：US12586863

申请日：2009-09-29

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01T1/20 ,  G01T1/164 ,  A61B6/03

CPC分类号： G01T1/1648 ,  A61B6/037 ,  G01T1/1611

摘要： A method and apparatus are disclosed for high-sensitivity Single-Photon Emission Computed Tomography (SPECT), and Positron Emission Tomography (PET). The apparatus includes a two-dimensional (2D) gamma detector array that, unlike a conventional SPECT machine, moves to different positions in a three-dimensional (3D) volume space near an emission source and records a data vector g which is a measure of gamma emission field. In particular, the 3D volume space in which emission data g is measured extends substantially along a radial direction r pointing away from the emission source, and unlike a conventional SPECT machine, each photon detector element in the 2D gamma detector array is provided with a very large collimator aperture. Data g is related to the 3D spatial density distribution f of the emission source, noise vector n, and a system matrix H of the SPECT/PET apparatus through the linear system of equations g=Hf+n. This equation is solved for f by a method that reduces the effect of noise.

摘要翻译： 公开了用于高灵敏度单光子发射计算机断层扫描（SPECT）和正电子发射断层扫描（PET）的方法和装置。 该装置包括二维（2D）伽马检测器阵列，其与传统的SPECT机器不同，在发射源附近的三维（3D）体积空间中移动到不同的位置，并记录数据矢量g，其是 伽马发射场。 特别地，其中测量发射数据g的3D体积空间基本上沿着远离发射源的径向方向r延伸，并且与传统的SPECT机不同，2D伽马检测器阵列中的每个光子检测器元件被提供有非常 大准直光圈。 数据g通过线性方程组g = Hf + n与发射源的3D空间密度分布f，噪声向量n和SPECT / PET装置的系统矩阵H有关。 该方程通过减少噪声影响的方法解决f。

公开(公告)号：US07577309B2

公开(公告)日：2009-08-18

申请号：US11450024

申请日：2006-06-10

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G06K9/40

CPC分类号： G06T5/50 ,  G06T7/571 ,  G06T2200/08 ,  H04N13/207

摘要： A method and apparatus for directly sensing both the focused image and the three-dimensional shape of a scene are disclosed. This invention is based on a novel mathematical transform named Rao Transform (RT) and its inverse (IRT). RT and IRT are used for accurately modeling the forward and reverse image formation process in a camera as a linear shift-variant integral operation. Multiple images recorded by a camera with different camera parameter settings are processed to obtain 3D scene information. This 3D scene information is used in computer vision applications and as input to a virtual digital camera which computes a digital still image. This same 3D information for a time-varying scene can be used by a virtual video camera to compute and produce digital video data.

摘要翻译： 公开了用于直接感测场景的聚焦图像和三维形状的方法和装置。 本发明基于一种名为Rao变换（RT）及其逆（IRT）的新型数学变换。 RT和IRT用于将相机中的正向和反向图像形成过程精确地建模为线性偏移量积分运算。 处理由具有不同相机参数设置的相机记录的多个图像以获得3D场景信息。 该3D场景信息用于计算机视觉应用中，并用作计算数字静止图像的虚拟数码相机的输入。 用于时变场景的相同3D信息可被虚拟摄像机用于计算和产生数字视频数据。

公开(公告)号：US4965840A

公开(公告)日：1990-10-23

申请号：US126407

申请日：1987-11-27

申请人： Muralidhara Subbarao

发明人： Muralidhara Subbarao

IPC分类号： G01C3/06 ,  G01B11/00 ,  G01C3/00 ,  G01C3/08 ,  G02B7/28

CPC分类号： G01C3/085

摘要： The present invention concerns a method of determining the distance between a surface patch of a 3-D spatial scene and a camera system. The distance of the surface patch is determined on the basis of at least a pair of images, each image formed using a camera system with either a finite or infinitesimal change in the value of at least one camera parameter. A first and second image of the 3-D scene are formed using the camera system which is characterized by a first and second set of camera parameters, and a point spread function, respectively, where the first and second set of camera parameters have at least one dissimilar camera parameter value. A first and second subimage is selected from the first and second images so formed, where the subimages correspond to the surface patch of the 3-D scene, the distance from which to the camera system, is to be determined. On the basis of the first and second subimages, a first constraint is derived between the spread parameters of the point spread function which corresponds to the first and second subimages. On the basis of the values of the camera parameters, a second constraint is derived between the spread parameters of the point spread function which corresponds to the first and second subimages. Using the first and second constrainsts, the spread parameters are then determined. On the basis of at least one of the spread parameters and the first and second sets of camera parameters, the distance between the camera system and the surface patch in the 3-D scene is determined.