US5617852A
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Method and apparatus for non-invasively determining blood analytes
Assignee: Sphere Medical Ltd
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Filing: 1995-04-06
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Granted: 1997-04-08
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Expires: 2015-04-06
Abstract
Abstract Method and apparatus for determining concentration of blood analytes non-invasively. Blood carrying tissue is illuminated with incident light at a selected frequency or frequencies. Light diffusely reflected from or transmitted through the tissue is collected, a portion of the reflected or transmitted light being frequency shifted with respect to the incident light by interaction with blood moving within the tissue. The frequency shifted portion of the light is analyzed to determine the concentration of blood analytes. Preferred embodiments are used to determine glucose concentration or measure the oxygenation of blood.
Inventors
- 👤 Alastair R. MacGregor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:44
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/14532
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
Method for determining concentration of blood analytes non-invasively comprising: illuminating blood carrying tissue with incident light at at least one selected frequency; collecting light diffusely reflected from or transmitted through the tissue, a portion of the reflected or transmitted light being frequency shifted with respect to the incident light by interaction with blood moving within the tissue; and analyzing the frequency shifted portion of the light to determine the concentration of blood analytes.
Claim 2
Dependent Claim
73 words
Method for determining concentration of blood analytes non-invasively comprising: illuminating blood carrying tissue with incident light at at least one selected frequency; collecting light diffusely reflected from or transmitted through the tissue, a portion of the reflected or transmitted light being frequency shifted with respect to the incident light by interaction with blood moving within the tissue; and analyzing the frequency shifted portion of the light to determine the concentration of blood analytes.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the blood analyte is glucose.
Claim 4
Dependent Claim
12 words
The method of claim 1 utilized to measure the oxygenation of blood.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the analyzed frequency shifted portion is shifted by more than a selected amount.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the analyzing step employs multivariate spectral analysis techniques.
Claim 7
Independent Claim
20 words
The method of claims 1, 2, 3, 4 or 5 wherein the incident light includes more than one selected frequency.
Claim 8
Dependent Claim
75 words
Apparatus for determining concentration of blood analytes non-invasively comprising: a light source for generating incident light at at least one selected frequency; a light detector for receiving light reflected from or transmitted through blood-containing tissue; apparatus for detecting a portion of the reflected or transmitted light which has been frequency shifted with respect to the incident light; and means for analyzing the frequency shifted portion of the light to determine the concentration of blood analytes.
Claim 9
Dependent Claim
75 words
Apparatus for determining concentration of blood analytes non-invasively comprising: a light source for generating incident light at at least one selected frequency; a light detector for receiving light reflected from or transmitted through blood-containing tissue; apparatus for detecting a portion of the reflected or transmitted light which has been frequency shifted with respect to the incident light; and means for analyzing the frequency shifted portion of the light to determine the concentration of blood analytes.
Claim 10
Dependent Claim
18 words
The apparatus of claim 7 wherein the light source generates incident light at more than one selected frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-04-07 | 2000-10-07 | 2001-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-07 | 2004-10-07 | 2005-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-07 | 2008-10-07 | 2009-04-08 | $7700.00 | Window Closed / Lapsed |