US4033330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transcutaneous pH measuring instrument
Assignee: HP Inc
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Filing: 1975-09-08
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Granted: 1977-07-05
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Expires: 1995-09-08
Abstract
Abstract A transcutaneous pH measuring device is provided in which a known volume of fluid is brought into equilibrium with body fluids through a membrane on a portion of skin whose surface layers have been stripped away. The fluid contains a pH sensitive dye. Optical measurements of the transmission characteristics of the fluid are obtained when the fluid is in the optical path. During portions of each operating cycle, the fluid is driven back into the vicinity of the skin to pH equilibrate with body fluids while standardization measurements are obtained using an optical plug of known transmission characteristics in the optical path.
Inventors
- 👤 Barry G. Willis
- 👤 Henry A. Schade, Jr.
- 👤 Michael J. Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:08
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1491; A61B5/14539; A61B5/1455; A61B5/14551; A61B5/14552
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
A device for measuring the concentration of a substance in the blood, said device comprising: a housing; optical radiation source means mounted within said housing for providing optical radiation having at least one predetermined frequency component; detector means mounted within said housing for detecting radiation at said at least one predetermined frequency; a measuring chamber positioned within said housing in an optical path between said source means and said detector means; means in the housing for maintaining a volumetric region adjacent an area of skin surface of the body when the device is brought into intimate contact with said area, said means allowing said substance in the blood to pass freely between the skin surface and said volumetric region while preventing the passage of undesired substances therebetween; a measuring fluid in said volumetric region, said fluid having radiation absorption characteristics as a function of wavelength which vary as a function of the concentration of said substance in the blood; and means for drawing measuring fluid from said volumetric region into said measuring chamber and forcing measuring fluid from said measuring chamber into the volumetric region.
Claim 2
Independent Claim
185 words
A device for measuring the concentration of a substance in the blood, said device comprising: a housing; optical radiation source means mounted within said housing for providing optical radiation having at least one predetermined frequency component; detector means mounted within said housing for detecting radiation at said at least one predetermined frequency; a measuring chamber positioned within said housing in an optical path between said source means and said detector means; means in the housing for maintaining a volumetric region adjacent an area of skin surface of the body when the device is brought into intimate contact with said area, said means allowing said substance in the blood to pass freely between the skin surface and said volumetric region while preventing the passage of undesired substances therebetween; a measuring fluid in said volumetric region, said fluid having radiation absorption characteristics as a function of wavelength which vary as a function of the concentration of said substance in the blood; and means for drawing measuring fluid from said volumetric region into said measuring chamber and forcing measuring fluid from said measuring chamber into the volumetric region.
Claim 3
Dependent Claim
45 words
A device as in claim 1 further comprising: standard means movably mounted in said housing for insertion into said measuring chamber when said measuring fluid is forced into said volumetric region, whereby said detector means is enabled to detect radiation passing through said standard means.
Claim 4
Dependent Claim
60 words
A device as in claim 2 wherein: said measuring fluid comprises a plurality of components, each component having a radiation transmission spectrum including a transmission minimum at a separate wavelength; and said detector means is adapted for detecting radiation at each of said separate wavelengths and at another common wavelength at which each of said components has a transmission maximum.
Claim 5
Dependent Claim
17 words
A device as in claim 3 wherein said measuring fluid comprises a solution of phenol red dye.
Claim 6
Dependent Claim
17 words
A device as in claim 2 wherein said measuring fluid comprises a solution of phenol red dye.
Claim 7
Dependent Claim
60 words
A device as in claim 1 wherein: said measuring fluid comprises a plurality of components, each component having a radiation transmission spectrum including a transmission minimum at a separate wavelength; and said dectector means is adapted for detecting radiation at each of said separate wavelengths and at another common wavelength at which each of said components has a transmission maximum.
Claim 8
Dependent Claim
22 words
A device as in claim 1 further comprising: temperature sensing and control means for regulating temperatures in the vicinity of said housing.
References Cited (Backward Citations)
US3461856A
Cited
US3578865A
Cited
US3659586A
Cited
US3795239A
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US3825342A
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US3918434A
Cited
US3793525A
Cited
US3811777A
Cited
US3811776A
Cited
US3878107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |