Kevin A Baldwin

US Patent:

7285091, Oct 23, 2007

Filed:

Jan 10, 2002

Appl. No.:

10/250882

Inventors:

David W. Blodgett - Ellicott City MD, US
Kevin C. Baldwin - Columbia MD, US
Donald D. Duncan - Silver Spring MD, US

Assignee:

The Johns Hopkins University - Baltimore MD

International Classification:

A61B 8/00
A61C 5/00

US Classification:

600437, 600438, 433215

Abstract:

A means of assessing the internal structure of teeth based upon use of high frequency, highly localized ultrasound (acoustic waves) generated by a short laser pulse is presented. In contrast to traditional contact transducer methods, laser-generated ultrasound is non-contact and non-destructive in nature and requires no special tooth surface preparation. Optical interferometric detection of ultrasound provides a complementary non-destructive, non-contact means for obtaining data with a very small detection footprint. The combination of laser-generated ultrasound and optical interferometric detection allows for in-vivo diagnostics of tooth health that is sensitive to the enamel/dentin, dentin/pulp, and dentin/cementum interfaces as well as a region of dead tracts in the dentin within a tooth.

US Patent:

20030114733, Jun 19, 2003

Filed:

Jan 27, 2003

Appl. No.:

10/351879

Inventors:

Richard Farrell - Laurel MD, US
Lorenz Happel - Ellicott City MD, US
Russell McCally - Columbia MD, US
Donald Duncan - Silver Spring MD, US
Kevin Baldwin - Baltimore MD, US

International Classification:

A61B001/267

US Classification:

600/167000, 600/200000

Abstract:

A hand-held ophthalmoscope modified by the removal or augmentation of the focusing wheel and the addition of a manual or automatic focusing lens system. An electronic imager (CCD array or video camera) is placed optically conjugate to a viewing screen such that focus operations performed by the examiner to adjust the image seen by the examiner on the screen also focuses the image on the electronic imager. This is accomplished by an optical system which includes a straight path from the viewing screen to the patient's eye with a beam splitter interposed to cause the image of the patient's eye to be reflected onto the imager. As a result, when the examiner uses the focusing lens system, manual or automatic, positioned between the beam splitter and the patient's eye, to affect the image viewed by the examiner, the focus of the imager is simultaneously affected as well. Alternatively, the image from the imager is sent to a liquid crystal display (LCD) in the instrument's eye piece; when the examiner focuses the image on the LCD, the image on the imager is focused simultaneously. Also provided is an automatic focusing system for the imager that operates independently of the examiner's focusing adjustments. An automatic focusing system for the imager can also be incorporated in the other two embodiments. The output from the electronic imager can be in digital or analog form and can consist of a single frame or a video stream.

US Patent:

20050234300, Oct 20, 2005

Filed:

Jun 15, 2005

Appl. No.:

11/153203

Inventors:

Richard Farrell - Laurel MD, US
Lorenz Happel - Ellicott City MD, US
Russell McCally - Columbia MD, US
Donald Duncan - Silver Spring MD, US
Kevin Baldwin - Baltimore MD, US

International Classification:

A61B001/04

US Classification:

600167000, 600109000

Abstract:

A hand-held ophthalmoscope modified by the removal or augmentation of the focusing wheel and the addition of a manual or automatic focusing lens system. An electronic imager (CCD array or video camera) is placed optically conjugate to a viewing screen such that focus operations performed by the examiner to adjust the image seen by the examiner on the screen also focuses the image on the electronic imager. This is accomplished by an optical system which includes a straight path from the viewing screen to the patient's eye with a beam splitter interposed to cause the image of the patient's eye to be reflected onto the imager. As a result, when the examiner uses the focusing lens system, manual or automatic, positioned between the beam splitter and the patient's eye, to affect the image viewed by the examiner, the focus of the imager is simultaneously affected as well. Alternatively, the image from the imager is sent to a liquid crystal display (LCD) in the instrument's eye piece; when the examiner focuses the image on the LCD, the image on the imager is focused simultaneously. Also provided is an automatic focusing system for the imager that operates independently of the examiner's focusing adjustments. An automatic focusing system for the imager can also be incorporated in the other two embodiments. The output from the electronic imager can be in digital or analog form and can consist of a single frame or a video stream.

US Patent:

20080232679, Sep 25, 2008

Filed:

Aug 17, 2006

Appl. No.:

11/465165

Inventors:

Daniel V. Hahn - Ellicott City MD, US
Donald D. Duncan - Silver Spring MD, US
Kevin C. Baldwin - Sykesville MD, US

International Classification:

G06K 9/00

US Classification:

382154

Abstract:

A 3-dimensional scanner capable of acquiring the shape, color, and reflectance of an object as a complete 3-dimensional object. The scanner utilizes a fixed camera, telecentric lens, and a light source rotatable around an object to acquire images of the object under varying controlled illumination conditions. Image data are processed using photometric stereo and structured light analysis methods to determine the object shape and the data combined using a minimization algorithm. Scans of adjacent object sides are registered together to construct a 3-dimensional surface model.

US Patent:

20210404956, Dec 30, 2021

Filed:

Sep 2, 2020

Appl. No.:

17/010007

Inventors:

- Baltimore MD, US
Kevin C. Baldwin - Baltimore MD, US
Andrea M. Brown - Ellicott City MD, US

International Classification:

G01N 21/53

Abstract:

An optical turbulence measurement system may include a camera assembly, a first optics assembly, a second optics assembly, and processing circuitry. The first optics assembly and the second optics assembly may be configured to magnify and direct a portion of a source beam received by a respective aperture to the camera assembly to be received as a two portions of a received beam. The processing circuitry may be configured to receive, from the camera assembly, a data representation of a first received beam from the first optics assembly and a second received beam from the second optics assembly, determine a focal spot displacement variance based on motion of a first focal spot corresponding to the first received beam relative to a second focal spot corresponding to the second received beam, and measure optical turbulence along a path of the source beam based on the focal spot displacement variance.

US Patent:

20200319364, Oct 8, 2020

Filed:

Apr 3, 2020

Appl. No.:

16/839598

Inventors:

- Baltimore MD, US
Kevin C. Baldwin - Sykesville MD, US

International Classification:

G01V 3/12
G01S 13/04

Abstract:

A holography sensor system is provided that includes an illuminator, a backscatter array, an array controller, and processing circuitry. The illuminator may be configured to output an illumination signal into a target volume. The backscatter array may comprise a plurality of backscatter elements. The array controller operably coupled to the backscatter elements, and the array controller may be configured to activate selected backscatter elements to enable the selected backscatter elements to transmit a backscatter signal in response to receipt of the illumination signal. The receiver may be configured to receive the backscatter signals from the selected backscatter elements. The processing circuitry may be configured to receive the backscatter data based on the backscatter signals from the receiver, aggregate the backscatter data with other backscatter data to form a holographic field measurement data set, and generate an image of the target volume based on the holographic field measurement data set.