University of Louisville Research Foundation

Kentucky Imaging Technologies

Aly Farag

Salwa Elshazly

Asem Ali

Sergey Y Chekmenev

M Sabry Hassouna

Mohamad Ghanoum

Ayman Sabry El-Baz

Sameh Yamany

Amal Farag

Mostafa Mohamad

David Tasman

Robert Curtin

The present development is a method for providing stable visualization of tubular objects. The method simplifies visualization using a Fly-Ln approach without loss of internal surface details. The method uses graphical programming, and can be easily integrated with commercially available visualization programs, such as Virtual Colonoscopy (VC) or Computed Tomography Colonography (CTC).

Stable visualization of tubular objects by the fly-in method with applications to computed tomography colonography

The three-dimensional (3D) reconstruction of visible part of the human jaw is becoming required for many diagnostic and treatment procedures. The present invention improves upon Statistical Shape from Shading (SSFS) framework by using a novel approach to automatically extract prior information. This two-step framework consists of interdental gingiva regions extraction for each individual tooth and detection of the centerline across the jaw span. These two steps help extract the anatomical landmark points and detect the status of the jaw. Experimental results highlight the accuracy of the extracted prior information and how this information boosts recovering 3D models of the human jaw.

Automatic extraction of interdental gingiva regions

The present development is a method for the visualization and automatic examination of the inner surface of tubular objects. The method uses a virtual camera rig arranged in a specific pattern within the tubular objects inner surface. The rig can be physical or virtual or hypothetical; graphics-based, providing the same functionality of a sequence of virtual cameras. This 'Fly-In' method is a more general visualization technique than techniques of the prior art, it is more flexible and does not create distortion, it does not require alternation to the surface for viewing and it can handle multi-branches with variable diameter. It can also provide a clear assessment of the inner surface for immediate examination of the object.

Fly-in visualization for virtual colonoscopy

The present invention is a method to stitch images of human teeth that are captured by an intraoral camera. Oral dental applications based on visual data pose various challenges such as low lighting conditions and saliva. Herein we describe a stitching algorithm of low-texture/low-resolution imaging. First, normals of tooth surface are extracted using shape from shading. An algorithm to rectify the imprecise values of the surface normal due to the oral environment is applied and normal maps generated. Second, the normal maps are used to detect, extract and match the corresponding features. Finally, to enhance the stitching process for these unidealized data, normal maps are used to estimate as-projective-as-possible warps. The proposed approach outperforms the state-of-the-art auto-stitching approach and shows a better performance in such cases of low-texture regions.

Frame stitching in human oral cavity environment using intraoral camera

The present invention is a unique method for tubular object visualization. The method involves rendering the exterior of the tube invisible while keeping the interior visible. This 'One-sided-transparency' technique renders a more complete view of the tube's interior. When applied to virtual colonoscopy (VC), it compares favorably to existing methods.

One-sided transparency: a novel visualization for tubular objects

A non-contact, passive method for measurement of arterial pulse from areas such as the major superficial arteries of the body through analysis of thermal IR images acquired by passive thermal IR imaging sensors, and through the modeling of the pulsatile nature of the blood flow and arterial pulse propagation in the circulatory system. The method is automatic and does not need operator input. The output waveform readily contains the information on heart rate, cardiac interbeat intervals, heart-rate variability and other features inherent in arterial pulse. The potential applications of this method, device and system are in the fields of non-contact and passive measuring cardiovascular and autonomic regulatory functions, mental and emotional loads, assessment of health in general, prediction of ill physiological and mental conditions, smart rooms, human-computer interaction, polygraph testing, intent identification, and any other fields where non-contact, passive monitoring of heart-rate and its variability is needed.

Non-contact and passive measurement of arterial pulse through thermal IR imaging, and analysis of thermal IR imagery

A method for detecting a nodule in image data including the steps of segmenting scanning information from an image slice to isolate lung tissue from other structures, resulting in segmented image data; extracting anatomic structures, including any potential nodules, from the segmented image data, resulting in extracted image data; and detecting possible nodules from the extracted image data, based on deformable prototypes of candidates generated by a level set method in combination with a marginal gray level distribution method. Embodiments of the invention also relate to an automatic method for detecting and monitoring a nodule in image data, where the method includes the steps of determining adaptive probability models of visual appearance of small 2D and large 3D nodules to control evolution of deformable models to get accurate segmentation of pulmonary nodules from image data; modeling a first set of nodules in image data with a translation and rotation invariant Markov-Gibbs random field (MGRF) of voxel intensities with pairwise interaction analytically identified from a set of training nodules; modeling a second subsequent set of nodules in image data by estimating a linear combination of discrete Gaussians; and integrating both models to guide the evolution of the deformable model to determine and monitor the boundary of each detected nodule in the image data.

Automatic detection and monitoring of nodules and shaped targets in image data

Embodiments of the invention utilize a variational framework for computing curve skeletons (CS) of objects whose cross section is not necessary tubular. Embodiments utilize an energy function, which is proportional to some medialness function, such that the minimum cost path between any two medial voxels in the shape is a curve skeleton. Different medialness functions include the Euclidean distance field and a modified version of the magnitude of the gradient vector flow (GVF), which results in two different energy functions. The first energy function controls the identification of the topological nodes of the shape from which curve skeletons start, while the second one controls the extraction of the curve skeletons. Preferred embodiments are completely automated since all parameters are analytically estimated. Embodiments are highly less sensitive to boundary noise, are able to extract the entire curve skeletons, as well as only part of it given the starting and the end voxels, and do not require voxels to be isotropic. In addition, computed curve skeletons are highly centered and form a connected graph. Preferred embodiments have been validated the framework both quantitatively and qualitatively against several 3D shapes of different complexity.

Method and software for shape representation with curve skeletons

An embodiment of the invention is method, which can be implemented in software, firmware, hardware, etc., for virtual fly over inspection of complex anatomical tubular structures. In a preferred embodiment, the method is implemented in software, and the software reconstructs the tubular anatomical structure from a binary imaging data that is originally acquired from computer aided tomography scan or comparable biological imaging system. The software of the invention splits the entire tubular anatomy into exactly two halves. The software assigns a virtual camera to each half to perform fly-over navigation. Through controlling the elevation of the virtual camera, there is no restriction on its field of view (FOV) angle, which can be greater than 90 degrees, for example. The camera viewing volume is perpendicular to each half of the tubular anatomical structure, so potential structures of interest, e.g., polyps hidden behind haustral folds in a colon are easily found. The orientation of the splitting surface is controllable, the navigation can be repeated at another or a plurality of another split orientations. This avoids the possibility that a structure of interest, e.g., a polyp that is divided between the two halves of the anatomical structure in a first fly over is missed during a virtual inspection. Preferred embodiment software conducts virtual colonoscopy fly over. Experimental virtual fly over colonoscopy software of the invention that performed virtual fly over on 15 clinical datasets demonstrated average surface visibility coverage is 99.59+/&#x2212;0.2%.

Virtual fly over of complex tubular anatomical structures

Systems and methods are provided through which a model-based vision system for dentistry which assists in diagnosis, treatment planning and surgical simulation. The present invention includes an integrated computer vision system that constructs a three-dimensional (3-D) model of the patient's dental occlusion using an intra-oral video camera. A modified shape from shading technique, using perspective projection and camera calibration, extracts the 3-D information from a sequence of two-dimensional images of the jaw. Data fusion of range data and 3-D registration techniques develop a complete 3-D digital jaw model. Triangulation of the 3-D digital model is then performed, and optionally, a solid 3-D model is reconstructed.

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Louisville, KY, United States of America

Aly Farag