US4479499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting the presence of caries in teeth using visible light
Assignee: Individual
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Filing: 1982-01-29
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Granted: 1984-10-30
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Expires: 2002-01-29
Abstract
Abstract A method and apparatus for detecting the presence of caries in human teeth using visible light. The tooth is exposed to light of relatively narrow bandwidths. The light from the tooth is preferably examined by two photomultipliers or visually each examining a different wavelength. Caries are detected when the difference in the intensity of the light from the tooth at those two wavelengths changes in a predetermined manner.
Inventors
- 👤 Robert R. Alfano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:45
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6486; A; A61; A61B; A61B5/00; A61B5/0059; A61B5/0082; A61B5/0088; G01N2021/6417; G01N2021/6421; G01N21/645; G01N2021/6484
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
130 words
A method for detecting the presence of caries of the teeth of a person comprising: radiating a region of the teeth to be examined with light; producing first and second signals corresponding to the intensity of the light scattered at first and second wavelengths, respectively, the intensity of difference of the scattered light between caries and non-carious regions at said first wavelength being measurably different than the intensity difference of the scattered light between caries and non-carious regions at said second wavelength; producing a third signal corresponding to the difference between said first and second signals; determining the value of said third signal when a known non-carious region is radiated; detecting the presence of caries in other regions by said third signal changing from said value in a predetermined manner.
Claim 2
Independent Claim
130 words
A method for detecting the presence of caries of the teeth of a person comprising: radiating a region of the teeth to be examined with light; producing first and second signals corresponding to the intensity of the light scattered at first and second wavelengths, respectively, the intensity of difference of the scattered light between caries and non-carious regions at said first wavelength being measurably different than the intensity difference of the scattered light between caries and non-carious regions at said second wavelength; producing a third signal corresponding to the difference between said first and second signals; determining the value of said third signal when a known non-carious region is radiated; detecting the presence of caries in other regions by said third signal changing from said value in a predetermined manner.
Claim 3
Dependent Claim
40 words
A method as in claim 1 including: selecting said first wavelength in the near neighborhood of the wavelength having the largest intensity of scattered light in non-carious regions; selecting said second wavelength to maximize the value of said third signal.
References Cited (Backward Citations)
US4290433A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |