Michael D Webber

US Patent:

6787776, Sep 7, 2004

Filed:

Aug 14, 2002

Appl. No.:

10/219993

Inventors:

Michael E. Webber - Culver City CA
Ronald K. Hanson - Cupertino CA
Jay B. Jeffries - Palo Alto CA

Assignee:

The Board of Trustees of Leland Stanford Junior University - Stanford CA

International Classification:

G01B 902

US Classification:

2503412, 2503416

Abstract:

A system and method utilizing a radiation source with a wavelength near 2 m (preferably 1993 nm) to measure the presence of ammonia, carbon dioxide and water vapor using spectroscopic techniques and a reduced measurement pressure is provided. Using radiation substantially near 2 m enables one to interrogate the P (3) ammonia transition at a frequency of 5016. 977 cm , which is isolated from water and carbon dioxide interference; the P(32) carbon dioxide transition at 5017. 030 cm , which is isolated from both ammonia and water interference, and a water transition at 5017. 100 cm. Moreover, a tunable radiation source that can sweep over the aforementioned ammonia and carbon dioxide and water features can measure the concentrations of all three species simultaneously. Using a sub-atmospheric pressure substantially near 100 Torr decreases the pressure broadening of different spectroscopic transitions, thereby isolating different absorption features, enabling species-specific measurements without interference, yet retaining sufficient peak absorption.

US Patent:

7064329, Jun 20, 2006

Filed:

Nov 4, 2003

Appl. No.:

10/701797

Inventors:

Michael Evan Webber - Culver City CA, US

Assignee:

Franalytica, Inc. - Santa Monica CA

International Classification:

G01N 21/35

US Classification:

25033912, 2503412, 250343

Abstract:

An amplifier-enhanced optical analysis system and method to optically analyze a molecular component of a gas, liquid, or solid. The amplifier-enhanced optical system comprises a laser, a light amplifier, and an optical analysis means, all optically coupled so that light at a predetermined wavelength in the near-infrared spectrum is transported from the laser, through the light amplifier, and to the optical analysis means, wherein the predetermined wavelength corresponds to an absorption feature of the molecular component. Optical analysis means preferably comprises photoacoustic analysis equipment.

US Patent:

7473229, Jan 6, 2009

Filed:

Dec 10, 2001

Appl. No.:

10/014977

Inventors:

Michael Evan Webber - Culver City CA, US

Assignee:

Pranalytica, Inc. - Santa Monica CA

International Classification:

A61B 5/02
G01N 1/22
G01N 31/00
G01N 33/497

US Classification:

600532, 73 233, 422 84

Abstract:

A method of analyzing alveolar breath. Breath is expired through an analysis chamber. The concentration of a first component of the breath is monitored as the breath is expired through the analysis chamber. When the concentration of the first component indicates that alveolar breath is in the analysis chamber, at least one concentration measurement of a second component of the breath is triggered. Concentration measurements of the second component are discontinued when the concentration of the first component indicates that alveolar breath is no longer passing through the analysis chamber.

US Patent:

7502115, Mar 10, 2009

Filed:

Nov 21, 2007

Appl. No.:

11/986632

Inventors:

Michael B. Pushkarsky - Los Angeles CA, US
Michael E. Webber - Culver City CA, US
Tyson MacDonald - Los Angeles CA, US

Assignee:

Pranalytica, Inc. - Santa Monica CA

International Classification:

G01J 3/30
G01N 21/00
G02B 6/00

US Classification:

356437, 356432, 356317, 2503412, 25033913

Abstract:

A method and apparatus architecture for detecting gases, particularly hazardous gases which should be detected in miniscule amounts. High sensitivity detection of chemical warfare agents (CWAs) is set forth with very low probability of false positives (PFP) by the use of an innovative laser-photoacoustic spectrometer (L-PAS). Detection of diisopropyl methylphosphonate (DIMP), a decomposition product of Sarin and a relatively harmless surrogate for the nerve gases, is made in the presence of other gases that are expected to be interferences in an urban setting. Detection sensitivity for DIMP in the presence of these interferences of better than 0. 45 ppb, which satisfies current homeland and military security requirements is shown as well as the first analysis of optical techniques for the detection of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in real world conditions.

US Patent:

20020158202, Oct 31, 2002

Filed:

Jan 8, 2002

Appl. No.:

10/042772

Inventors:

Michael Webber - Culver City CA, US
Ronald Hanson - Cupertino CA, US
Scott Sanders - Madison WI, US

International Classification:

G01J005/02
F23N005/00

US Classification:

250/339130, 431/075000

Abstract:

The present invention provides a laser-based method and apparatus that uses absorption spectroscopy to detect the mole fraction of COin a high temperature gas stream. In a preferred embodiment, a distributed feedback based diode laser sensor operating at a wavelength near 1996.89 nm (5007.787 cm) interrogates the R(50) transition of the +2 + COabsorption band in the near infrared. This transition is specifically chosen based on its superior linestrength and substantial isolation from interfering absorption by high-temperature HO, CO, NH, NO, NO, and other species commonly present in combustion or other high-temperature gas flows.

US Patent:

20030038237, Feb 27, 2003

Filed:

Aug 21, 2001

Appl. No.:

09/935011

Inventors:

Michael Webber - Culver City CA, US

Assignee:

Pranalytica, Inc.

International Classification:

G01N021/35

US Classification:

250/339120

Abstract:

An amplifier-enhanced optical analysis system and method to optically analyze a molecular component of a gas, liquid, or solid. The amplifier-enhanced optical system comprises a laser, a light amplifier, and an optical analysis means, all optically coupled so that light at a predetermined wavelength in the near-infrared spectrum is transported from the laser, through the light amplifier, and to the optical analysis means, wherein the predetermined wavelength corresponds to an absorption feature of the molecular component. Optical analysis means preferably comprises photoacoustic analysis equipment.

US Patent:

20070229834, Oct 4, 2007

Filed:

Oct 21, 2005

Appl. No.:

11/256377

Inventors:

C. Kumar Patel - Los Angeles CA, US
Michael Pushkarsky - Los Angeles CA, US
Michael Webber - Culver City CA, US
Tyson MacDonald - Los Angeles CA, US

International Classification:

G01N 21/61

US Classification:

356432000, 356437000

Abstract:

A method and apparatus architecture for detecting gases, particularly hazardous gases which should be detected in miniscule amounts. High sensitivity detection of chemical warfare agents (CWAs) is set forth with very low probability of false positives (PFP) by the use of an innovative laser-photoacoustic spectrometer (L-PAS). Detection of diisopropyl methylphosphonate (DIMP), a decomposition product of Sarin and a relatively harmless surrogate for the nerve gases, is made in the presence of other gases that are expected to be interferences in an urban setting. Detection sensitivity for DIMP in the presence of these interferences of better than 0.45 ppb, which satisfies current homeland and military security requirements is shown as well as the first analysis of optical techniques for the detection of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in real world conditions.