Surface Reconstruction for a DIET breast cancer screening system

This paper outlines a method for accurately tracking surface motion on an actuated breast as part of a Digital Image-based Elasto-Tomography (DIET) breast cancer screening project. The tracking method is validated in both simulation and experiment on a silicon breast phantom which has similar elasticity characteristics to human breast tissue. Given mean reprojection error ranges between 0.3 and 0.5 pixels for 2M pixel cameras the end result is sub-millimetre surface tracking of a silicon phantom actuated at 100 Hz. This highly accurate, fast and low cost method of tracking is thus well suited to a DIET system

Surface motion reconstruction for a DIET system

A Digital Image-based Elasto-Tomography (DIET) system for breast cancer screening has been proposed in which the elastic properties of breast tissue are recovered by solving an inverse problem on the surface motion of a breast under low frequency (50-100 Hz) mechanical actuation. The proposed means for capturing the surface motion of the breast in 3D is to use a stroboscope to capture images from multiple digital cameras at preselected phase angles. Photogrammetric techniques are then used to reconstruct matched point features in 3D. Since human skin lacks high contrast visual features, it is necessary to introduce artificial fiducials which can be easily extracted from digital images. The chosen fiducials are points in three different colours in differing proportions randomly applied to the skin surface. A three-dimensional signature which is invariant to locally Euclidean transformations between images is defined on the points of the lowest proportion colour. The approximate local Euclidean invariance between adjacent frames enables these points to be matched using this signature. The remaining points are matched by interpolating the transformation of the matched points. The points between the two cameras are matched by matching ellipses in image space. Successful results are presented for simulated image sequences and for images of a mechanically actuated viscoelastic gel phantom showing that the overall procedure is suitable for a DIET system

Digital Imaging Based Screening and Detection of Breast Cancer

Keynote speechBreast cancer affects thousands of (primarily) women and is best treated when detected early. Currently, the primary form of (successful) breast cancer detection is manual palpation, which detects tumors through their high contrast stiffness relative to the surrounding tissue. The DIET system (Digital Image-based Elasto-Tomography) exploits this contrast to create a novel approach to breast cancer detection based on material property reconstruction of harmonic excitation data from the surface of the breast. These motions are measured using digital imaging in combination with a variety of novel imaging algorithms and approaches. The result is a conceptual technology approach to breast cancer screening that is small, potentially low cost, scalable, and does not involve X-rays, thus opening the opportunity to offer screening at any age with potentially greater compliance than found with mammography. Relying on silicon technologies it is also highly scalable as these technologies improve (regularly) in resolution and capability. This seminar presents the overall DIET concept and the research successes and "difficulties" to date at the University of Canterbury in New Zealand. A particular focus is paid to providing an overview of the multi-disciplinary methods, technologies and algorithms required to apply material property reconstruction from a strictly optical (digital imaging and computer vision) based sensing system in this Bio-Engineering application. Hence, the talk covers all the major technological modalities required to see this form of breast cancer screening emerge. An overview of methods is given and results are shown for proof of concept simulation, all major imaging and image processing aspects, and recent proof of concept silicone phantom studies on a pre-pre-prototype experimental system

Proximal deep vein thrombosis after hip replacement for oncologic indications

10.2106/JBJS.D.02926Journal of Bone and Joint Surgery - Series A8851066-1070JBJS

Determining the optimal size of small molecule mixtures for high throughput NMR screening

High-throughput screening (HTS) using NMR spectroscopy has become a common component of the drug discovery effort and is widely used throughout the pharmaceutical industry. NMR provides additional information about the nature of small molecule-protein interactions compared to traditional HTS methods. In order to achieve comparable efficiency, small molecules are often screened as mixtures in NMR-based assays. Nevertheless, an analysis of the efficiency of mixtures and a corresponding determination of the optimum mixture size (OMS) that minimizes the amount of material and instrumentation time required for an NMR screen has been lacking. A model for calculating OMS based on the application of the hypergeometric distribution function to determine the probability of a \u27hit\u27 for various mixture sizes and hit rates is presented. An alternative method for the deconvolution of large screening mixtures is also discussed. These methods have been applied in a high-throughput NMR screening assay using a small, directed library