Charles H Richardson

US Patent:

55558828, Sep 17, 1996

Filed:

Aug 24, 1994

Appl. No.:

8/295349

Inventors:

Charles A. Richardson - San Francisco CA
Michael Bernstein - San Ramon CA
Jerry K. Okikawa - Oakland CA
Terrence R. Bennett - Richmond CA

Assignee:

Nellcor Incorporated - Pleasanton CA

International Classification:

A61B 500

US Classification:

128633

Abstract:

The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.

US Patent:

58852131, Mar 23, 1999

Filed:

Sep 17, 1997

Appl. No.:

8/932747

Inventors:

Charles A. Richardson - San Francisco CA
Michael Bernstein - San Ramon CA
Jerry K. Okikawa - Oakland CA
Terrence R. Bennett - Richmond CA

Assignee:

Nellcor Puritan Bennett Incorporated - Pleasanton CA

International Classification:

A61B 500

US Classification:

600336

Abstract:

The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.

US Patent:

53682246, Nov 29, 1994

Filed:

Oct 23, 1992

Appl. No.:

7/965684

Inventors:

Charles A. Richardson - San Francisco CA
Michael Bernstein - San Ramon CA
Jerry K. Okikawa - Oakland CA
Terrence R. Bennett - Richmond CA

Assignee:

Nellcor Incorporated - Pleasanton CA

International Classification:

A61B 500

US Classification:

128633

Abstract:

The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.

US Patent:

61730629, Jan 9, 2001

Filed:

Mar 16, 1994

Appl. No.:

8/214169

Inventors:

Farid Dibachi - San Carlos CA
Charles S. Richardson - Tucson AZ
Arnold S. Lippa - Tucson AZ

Assignee:

Hearing Innovations Incorporated - Tucson AZ

International Classification:

H04R 2500

US Classification:

381312

Abstract:

Apparatus and method for shifting the frequency range of an audio frequency range signal using digital frequency shifting and single sideband amplitude modulation techniques. In one embodiment, a frequency shifted single sideband, amplitude modulated signal is formed for application to the human hearing sensory system to provide enhanced hearing for hearing impaired persons. In another embodiment, the audio signal is shifted to an ultrasonic frequency range utilizing digital signal processing techniques in which an audio frequency signal is frequency shifted by modulation to a carrier frequency and in which a single sideband modulated signal is formed. The digital single sideband amplitude modulation techniques of this embodiment are also applicable to digital modulation systems for uses other than in hearing aids. In another embodiment, analog single sideband modulation is utilized for frequency shifting in a hearing aid application.

US Patent:

57133557, Feb 3, 1998

Filed:

Apr 18, 1996

Appl. No.:

8/637002

Inventors:

Charles A. Richardson - San Francisco CA
Michael Bernstein - San Ramon CA
Jerry K. Okikawa - Oakland CA
Terrence R. Bennett - Richmond CA

Assignee:

Nellcor Puritan Bennett Incorporated - Pleasanton CA

International Classification:

A61B 500

US Classification:

128633

Abstract:

The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.