Plaque Detection Device Using Dual-Wavelength Fluorescence Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plaque detecting devices require users to find a tooth surface without biological deposits for calibration, which is difficult and time-consuming.
Innovation Solution
A plaque detecting device that uses ultraviolet or blue excitation light and includes first and second light receiving units to determine the presence of plaque by analyzing the intensity of spectral components specific to plaque and enamel, eliminating the need for calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plaque detecting device compares fluorescent light intensity from a tooth surface to a reference value obtained from a tooth surface without biological deposits, then the presence or absence of plaque can be determined, but the user must perform a calibration operation to find and save the reference value, which is time-consuming and troublesome
Solution Approach 1:
The device automatically determines whether plaque is present by comparing fluorescent light intensity between two tooth surfaces without requiring the user to manually find a reference tooth surface or perform calibration operations. The system self-selects and compares appropriate tooth surfaces, eliminating the troublesome calibration step while maintaining detection accuracy
Solution Approach 2:
Instead of requiring the user to find a clean reference tooth surface and save it as a baseline, the invention inverts the approach by automatically selecting two tooth surfaces to compare and determining plaque presence based on their relative fluorescent light intensities, without needing a pre-established reference value
2Ease of operation
If a plaque detecting device uses spectral analysis to identify plaque, then calibration-free operation is achieved, but the device complexity increases with multiple light receiving units and spectral processing
Solution Approach 1:
The device divides the spectral analysis into two separate wavelength regions, each handled by a dedicated light receiving unit. The first unit captures the plaque-specific peak region, while the second unit captures the enamel peak region. This segmentation simplifies the spectral processing by focusing on specific wavelength ranges rather than analyzing the entire spectrum
Solution Approach 2:
Each light receiving unit is optimized for a specific wavelength region with distinct spectral characteristics. The first unit targets the local spectral feature of plaque (peak at 630 nm), while the second unit targets the local spectral feature of enamel (peak at 480 nm), allowing for specialized detection without requiring full-spectrum analysis
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables users to determine the presence or absence of plaque through a simple operation, without the need for calibration, and when integrated into a toothbrush, allows for real-time detection during brushing.
Implementation Method 1
a plaque detecting device which irradiates light onto the surface of a tooth and determines the presence or absence of plaque based on fluorescent light coming from the tooth surface or plaque
Implementation Method 2
the first light receiving unit extracts, from the radiated light, a spectral component of a first wavelength region having a predetermined lower limit wavelength and including the wavelength range of fluorescent light specific to plaque
Implementation Method 3
the second light receiving unit extracts, from the radiated light, a spectral component of a second wavelength region having a predetermined lower limit wavelength lower than the lower limit wavelength of the first wavelength region and including the wavelength range of fluorescent light specific to enamel
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3~4
AI summary
The plaque detecting device of the present invention comprises a light emitting unit (450) which irradiates ultraviolet or blue excitation light (L) toward the tooth surface (99a), and a first and second light receiving units (402) which receive radiated light (L') from the tooth surface (99a). The first light receiving unit extracts the spectral component of a first wavelength region including the wavelength range of fluorescent light specific to plaque from the radiated light (L'), and obtains a first output value corresponding to the intensity of that spectral component. The second light receiving unit extracts, from the radiated light (L'), the spectral component of a second wavelength region containing the wavelength range of the fluorescent light specific to enamel and having a predetermined lower limit wavelength below the lower limit wavelength of the first wavelength region, and obtains a second output value corresponding to the intensity of this spectral component. Determination of the relative magnitude of the ratio between the first output value and the second output value as compared to a first threshold value is performed. Determination of the relative magnitude of the difference between the first output value and the second output value as compared to a second threshold value is performed.