David A Levin

US Patent:

6567567, May 20, 2003

Filed:

Jan 24, 2000

Appl. No.:

09/490412

Inventors:

David N. Levin - Chicago IL
Scott Nagle - Oak Park IL

Assignee:

ARCH Development Corp. - Chicago IL

International Classification:

G06K 936

US Classification:

382284, 382128

Abstract:

A method and apparatus are provided for transceiving a signal. The method includes the steps of transmitting a superposed frequency component of the signal within each of a plurality of non-adjacent frequency bands, using analogue or digital filters within a receiver to suppress all signals outside the plurality of frequency bands and to pass a filtered signal within the plurality of non-adjacent frequency bands, determining a set of substantially non-uniformly spaced times at which the filtered signal within the plurality of non-adjacent frequency bands should be sampled and sampling the filtered signal at the determined times to provide sampled data. The method further includes the steps of Fourier transforming subsets of the sampled data, linearly combining the Fourier transformed subsets using a reconstruction matrix and extracting the signal from the linear combinations of the Fourier transformed subsets.

US Patent:

6687657, Feb 3, 2004

Filed:

Sep 25, 2001

Appl. No.:

09/962768

Inventors:

David N. Levin - Chicago IL 60614

International Classification:

G06F 1300

US Classification:

702189, 702125, 702126, 702178, 702198

Abstract:

The inventive method and apparatus include sensory devices that invariantly represent stimuli in the presence of processes that cause systematic sensor state transformations. Such processes include: 1) alterations of the devices detector, 2) changes in the observational environment external to the sensory device and the stimuli, and 3) certain modifications of the presentation of the stimuli themselves. A specific embodiment of the present invention is an intelligent sensory device having a âfront endâ comprised of such a representation âengineâ. The detectors of such a sensory device need not be recalibrated, and its pattern analysis module need not be retrained, in order to account for the presence of the above-mentioned transformative processes. Another embodiment of the present invention is a communications system that encodes messages as representations of signals. The message is not corrupted by signal transformations due to a wide variety of processes affecting the transmitters, receivers, and the channels between them.

US Patent:

20080147763, Jun 19, 2008

Filed:

Dec 7, 2007

Appl. No.:

11/952284

Inventors:

David Levin - Chicago IL, US

International Classification:

G06F 17/14

US Classification:

708400

Abstract:

Given a time series of possibly multicomponent input data, the method and apparatus includes a device that finds a time series of “source” components, which are possibly nonlinear combinations of the input data components and which can be partitioned into groups that are statistically independent of one another. These groups of source components are statistically independent in the sense that the phase space density function of the source time series is approximately equal to the product of density functions, each of which is a function of the components (and their time derivatives) in one of the groups. In a specific embodiment, an unknown mixture of data from multiple independent source systems (e.g., a transmitter of interest and noise producing system) is processed to extract information about at least one source system (e.g., the transmitter of interest).

US Patent:

50819925, Jan 21, 1992

Filed:

Nov 30, 1990

Appl. No.:

7/622204

Inventors:

David N. Levin - Chicago IL
Xiaoping Hu - Chicago IL
Paul C. Lauterbur - Urbana IL
Thomas Spraggins - Charlottesville VA

Assignee:

Siemens Medical Systems - Iselin NJ

International Classification:

A61B 5055

US Classification:

1286532

Abstract:

An MR imaging study precedes an MR spectroscopic study. Structural information from the imaging study is combined with MR spectra from the spectroscopic study to produce localized MR spectra.

US Patent:

60931531, Jul 25, 2000

Filed:

Aug 4, 1998

Appl. No.:

9/128863

Inventors:

David N. Levin - Chicago IL

International Classification:

A61B 504

US Classification:

600558

Abstract:

A method for measuring perception of an observer comprises a) selecting a first, second, and third stimulus and presenting the stimuli to the observer; b) determining observer-defined fourth stimulus such that the observer perceives the fourth stimulus to be related to the third stimulus in the same way as the observer perceives the second stimulus to be related to the first stimulus; c) selecting a new first, second, and third stimulus, at least one of the new stimuli corresponding to a stimulus point that is different from the stimulus points corresponding to the previously selected stimulus; d) determining a new observer-defined fourth stimulus such that the observer perceives the new fourth stimulus to be related to the new third stimulus in the same way as the observer perceives the new second stimulus to be related to the new first stimulus; and e) performing steps (c) through (d) until a predetermined number of sets of four stimuli are determined.

US Patent:

60186003, Jan 25, 2000

Filed:

Apr 15, 1998

Appl. No.:

9/061513

Inventors:

David N. Levin - Chicago IL
Scott Nagle - Oak Park IL

Assignee:

ARCH Development Corp. - Chicago IL

International Classification:

G06K 936

US Classification:

382284

Abstract:

A method and apparatus are provided for acquiring and reconstructing an image. The method includes the steps of obtaining prior knowledge of the image, possibly by coarse sampling of the image and using the obtained prior knowledge of the image to identify relative locations of structures having relatively high contrast edges. The method further includes the steps of prescribing a set of k-space locations based upon the relative locations of the structures in order to achieve comparable eigenvalues of a reconstruction matrix and sampling the k-space at the prescribed k-space locations to obtain k-space sample data. The k-space sample data are decomposed into background data and edge data. The background data are Fourier transformed to reconstruct a background image component. Similarly, subsets of the edge data are Fourier transformed and the reconstruction matrix is used to form a linear combination of these Fourier transformations in order to reconstruct an edge image component.

US Patent:

57684138, Jun 16, 1998

Filed:

Oct 4, 1995

Appl. No.:

8/539204

Inventors:

David N. Levin - Chicago IL
Robert P. Grzeszczuk - Oak Park IL

Assignee:

Arch Development Corp. - Chicago IL

International Classification:

G06K 900

US Classification:

382173

Abstract:

A method for segmenting an image in which an arbitrarily shaped contour is deformed stochastically until it approximates the contour of a target object. The evolution of the contour is controlled by a simulated annealing process which causes the contour to settle into a global minimum of an image-derived "energy" function. The non-parametric energy function is derived from the statistical properties of previously-segmented training images. High computational complexity is avoided by using an efficient method of introducing a random local perturbation, and assuring the resulting shape changes are unbiased. This method for perturbing the contour allows for execution times several orders of magnitude shorter than in simple implementations.

US Patent:

58609369, Jan 19, 1999

Filed:

Aug 2, 1996

Appl. No.:

8/691615

Inventors:

David N. Levin - Chicago IL

International Classification:

A61B 1300

US Classification:

600558

Abstract:

A method is used for measuring perception of an observer using a stimulus output device for presenting stimuli to the observer, and a stimulus manipulation device permitting the observer to modify the presented stimuli by selecting related stimuli from a database of stimuli. The method includes the steps of: a) selecting a sequence of stimuli from the database of stimuli, the stimuli represented as stimulus points contained in a stimulus space; b) determining a reference transformation of a beginning stimulus point of the sequence of stimuli, the reference transformation being presented to the observer by the stimulus output device; c) selecting a limited portion of the sequence of stimuli, the limited portion of the sequence defined between the beginning stimulus point and an ending stimulus point, the limited portion of the sequence being presented to the observer by the stimulus output device; d) determining an observer-defined transformation applied to the ending stimulus point of the limited portion of the sequence such that the observer perceives the observer-defined transformation applied to the ending stimulus point to be perceptually equivalent to the reference transformation applied to the beginning stimulus point; e) selecting a new limited portion of the sequence of stimuli, the new limited portion of the sequence defined by stimulus points selected from the database, at least a portion of the new limited portion having stimulus points different from the stimulus points defining the previously selected limited portion of the sequence; f) determining another observer-defined transformation applied to an ending stimulus point of the new limited portion of the sequence such that the observer perceives the observer-defined transformation to be equivalent to the previous observer-defined transformation; and g) performing steps (e) through (f) until a predetermined number of limited portions of the sequence of stimuli are processed such that the observer perceives each observer-defined transformation to be equivalent to previous observer-defined transformations.