Bill Katz

The Digital Humans CD-ROM documents the digitization of male and female cadavers by the Visible Human Project. When the Visible Human datasets were released to the public a decade ago, I developed programs for segmenting and reconstructing 3D models using voxel-based computer graphics techniques. It's my intention to put into the public domain the full content of the CD-ROM, including a series of videos showing the actual digitization of the cadavers.

This is an overview of science & engineering topics of interest, past and present.

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Brain-Computer Interface

BCI: Research allowing direct communication between the computer and the human mind. A Brain-Computer interface could be used to control prosthetic devices, significantly enhancing the quality of life for handicapped individuals. The NIH has formed the Neural Prosthesis Program, which holds yearly workshops and funds some of the research.

BCI research is proceeding along invasive, intra-cortical lines as well as more data-processing intensive EEG-based approaches. The latter methods affix EEG leads on the scalp, record brain waves, and employ powerful computer methods to decipher the results. Noise is a problem, so researchers have embraced the more invasive approach of implanting chips directly into the brain.

INTRODUCTION

The Digital Humans CD-ROM is a multimedia exploration of the Visible Human Project intended for the general public. An important part of the CD-ROM was a variety of 3D anatomy reconstructions using both the cryosection and computerized tomography (CT) cross-sectional images. This abstract describes the basic process used in segmenting the raw datasets and the graphics algorithms used in generating the 3D anatomy.

Retrospective Model-Based Reduction of Gradients in MR Images
(follow link for PDF version)

Technical Paper -- 1995

William T. Katz, Ph.D., M.D.
Neal F. Kassell, M.D.
James R. Brookeman, Ph.D.

Operations using image intensities often assume substances have spatially invariant intensities. This assumption may be incorrect in magnetic resonance imaging due to low spatial frequency intensity variations introduced by the radio frequency coil. This paper describes a method for indirect calculation of the coil sensitivity profile which uses the imaged brain as a qualitative phantom. The algorithm estimates ideal image intensities for likely brain voxels in a subsampled fashion, calculates an averaged sensitivity profile at each point in the subsampled grid, and then fits an order two three-dimensional polynomial to the averaged sensitivities. Since a voxel-based anatomic model is used to select the brain data points, user interaction is reduced to the initial registration of the image to Talairach space.