Detecting distance of a probe to pulp of a tooth
AssigneeKoninklijke Philips N.V.
InventorsCristian Nicolae Presura, Jindrich Charvat, Martin Pekar
Life of this patent
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Abstract
A method and an apparatus for detecting distance of a probe contacting a tooth surface to pulp of a tooth by determining an indication of thickness of dentine of the tooth is provided. The method comprises illuminating the dental tissue of the tooth with a probe, then receiving the data representing scattered light from the dental tissue. A spectra of the scattered light is then obtained and analyzed to further obtain a spectral analysis re-suit. An indication of the thickness of the dentine of the tooth is then determined based on the spectral analysis result. The method may help to prevent the unintended exposure of pulp during dental treatments such as drilling.
Claims7
A method for detecting distance of a probe to pulp of a tooth by determining an indication of thickness of dentine of the tooth, comprising:
- providing a probe having a light source and a spectrometer optically coupled to the probe, and a processor operatively coupled to the spectrometer;
- receiving data representing scattered light from dental tissue illuminated by the light source of the probe, wherein the scattered light comprises light having a wavelength in the range of 300-800 nm;
- obtaining spectra of the scattered light in a wavelength range of 300-800 nm by the spectrometer;
- automatically detecting, by the processor executing a peak-detection algorithm, light absorption peaks in the spectra characteristic of blood;
- computing, by the processor, an integrated amplitude of the spectra over a wavelength sub-range of 400-600 nm;
- and
- determining, by the processor, thickness of the dentine of the tooth based on (i) whether the integrated amplitude exceeds a predetermined threshold value and (ii) whether the light absorption peaks are detected in the range 400 nm to 600 nm,
- wherein:
- when the integrated amplitude exceeds the predetermined threshold value and no light absorption peaks are detected, the thickness of the dentine is determined to be in the range of 2 mm to 1 mm;
- when the integrated amplitude does not exceed the predetermined threshold value and light absorption peaks are detected, the thickness of the dentine is determined to be in the range 1 mm to 0.2 mm;
- and
- when the integrated amplitude does not exceed the predetermined threshold value and light absorption peaks are not detected, the thickness of the dentine is determined to be less than 0.2 mm;
- and
- outputting, by the processor, a shut-off signal to halt dental drilling when the determined thickness reaches a predetermined safety threshold.
A dental apparatus for determining distance of a probe to pulp of a tooth by determining an indication of thickness of dentine of the tooth, comprising:
- a probe configured to illuminate dental tissue of the tooth with light and to detect scattered light from the dental tissue, wherein the light comprises having a wavelength range of 300-800 nm;
- a processor configured to:
- obtain spectra of the detected scattered light in a wavelength range of 300-800 nm;
- obtain a spectral analysis result from the spectra, wherein obtaining a spectral analysis result from the spectra comprises detecting light absorption peaks having a wavelength range characteristic to a wavelength range of absorption spectra of blood;
- determine an indication of thickness of the dentine of the tooth based on the spectral analysis result;
- and
- determine that the thickness of the dentine is in the range of 2 mm to 1 mm, if the integrated amplitude of the spectra in the range 400 nm to 600 nm exceeds a predetermined threshold value and no light absorption peaks are detected in the range 400 nm to 600 nm,
- determine that the thickness of the dentine is in the range 1 mm to 0.2 mm, if the integrated amplitude of the spectra in the range 400 nm to 600 nm does not exceed the predetermined threshold value and light absorption peaks are detected in the range of 400 nm to 600 nm, and
- determine that the thickness of the dentine is less than 0.2 mm, if the integrated amplitude of the spectra in the range 400 nm to 600 nm does not exceed the predetermined threshold value and light absorption peaks are not detected in the range 400 nm to 600 nm.
Dependencies are inferred from the claim text.