Patent US5842981A successfully refreshed from Google Patents.
US5842981A
Expired / Lapsed
US
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Direct to digital oximeter
Assignee: Indusind Bank Ltd
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Filing: 1996-07-17
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Granted: 1998-12-01
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Expires: 2016-07-17
Abstract
Abstract An oximeter for non-invasively measuring the oxygen saturation in blood with increased speed and accuracy. The device includes a sensor unit which can be attached to a patient and an oximeter which determines the oxygen saturation in the blood based on signals received from the sensor. In the present invention, the detected signal is immediately converted to a digital value.
Inventors
- 👤 Michael T. Larsen
- 👤 James L. Reuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:49
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/14551
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
97 words
An oximeter for non-invasively measuring arterial oxygen saturation, comprising: a sensor including at least first and second light emitting devices for producing light in at least two wavelengths; at least one photodetector for detecting said light, after passing through a tissue sample containing a pulsating blood supply, and for producing an analog electrical current signal representing the absorption of each wavelength of said light; an analog to digital converter for converting said analog electrical current signal to a digital voltage signal; and a processing unit for processing said digital voltage signal to calculate an arterial oxygen saturation.
Claim 2
Dependent Claim
97 words
An oximeter for non-invasively measuring arterial oxygen saturation, comprising: a sensor including at least first and second light emitting devices for producing light in at least two wavelengths; at least one photodetector for detecting said light, after passing through a tissue sample containing a pulsating blood supply, and for producing an analog electrical current signal representing the absorption of each wavelength of said light; an analog to digital converter for converting said analog electrical current signal to a digital voltage signal; and a processing unit for processing said digital voltage signal to calculate an arterial oxygen saturation.
Claim 3
Dependent Claim
16 words
The oximeter of claim 1 wherein said sensor comprises LED's which produce light in three wavelengths.
Claim 4
Dependent Claim
19 words
The oximeter of claim 1 wherein said analog to digital converter comprises a charge digitizing analog to digital converter.
Claim 5
Dependent Claim
32 words
The oximeter of claim 1 wherein said analog to digital converter has sufficient range to measure large DC signals and sufficient resolution to represent small AC signals modulated on the DC signals.
Claim 6
Dependent Claim
19 words
The oximeter of claim 1 wherein said analog to digital converter includes a current integrator in the first stage.
Claim 7
Dependent Claim
15 words
The oximeter of claim 1 wherein said processing unit comprises a computer executing software routines.
Claim 8
Dependent Claim
15 words
The oximeter of claim 1 further comprising a stored look-up table for calculating oxygen saturation.
Claim 9
Dependent Claim
19 words
The oximeter of claim 1 further comprising a stored look-up table stored in flash EPROM for calculating oxygen saturation.
Claim 10
Independent Claim
83 words
A method for non-invasively measuring arterial oxygen saturation, comprising the steps of: producing light of at least first and second wavelengths; directing said light at a tissue sample containing a pulsating blood supply; detecting said light, after passing through said tissue sample, and producing an analog electrical current signal representing the absorption rate of each wavelength of said light; then converting said analog electrical current signal to a digital voltage signal; then processing the digital voltage signal to calculate an arterial oxygen saturation.
Claim 11
Independent Claim
83 words
A method for non-invasively measuring arterial oxygen saturation, comprising the steps of: producing light of at least first and second wavelengths; directing said light at a tissue sample containing a pulsating blood supply; detecting said light, after passing through said tissue sample, and producing an analog electrical current signal representing the absorption rate of each wavelength of said light; then converting said analog electrical current signal to a digital voltage signal; then processing the digital voltage signal to calculate an arterial oxygen saturation.
Claim 12
Dependent Claim
22 words
The method as defined in claim 9 further including the step of utilizing a stored look-up table to calculate the oxygen saturation.
Claim 13
Dependent Claim
30 words
The method as defined in claim 9 further including the steps of storing a look-up table in a flash EPROM and utilizing this look-up table to calculate the oxygen saturation.
Claim 14
Dependent Claim
22 words
The method as defined in claim 9 further including the steps of identifying and filtering ambient noise from the digital voltage signal.
Claim 15
Dependent Claim
29 words
The method as defined in claim 9 further including the step of mathematically integrating the analog electrical current signal before converting said current signal to said input digital voltage.
Claim 16
Dependent Claim
42 words
The method as defined in claim 9 further including the step of demultiplexing the digital voltage signal to provide a first value representative of light detected of the first wavelength and a second value representative of light detected of the second wavelength.
Claim 17
Dependent Claim
19 words
The method as defined in claim 14 further including the step of digitally filtering the first and second values.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-30 | 2002-06-01 | 2002-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-30 | 2006-06-01 | 2006-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-30 | 2010-06-01 | 2010-12-01 | $7700.00 | Window Closed / Lapsed |