Non-invasive SPF Measurement Using Eosin Photochemistry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining sun protection factors in cosmetics and sunscreens are invasive, cause harm to test subjects, and are not physiologically realistic, as they rely on erythema induction with UV radiation, which can lead to skin damage and are limited to specific spectral ranges.
Innovation Solution
A measuring system with multiple radiation sources and a spectrometer that allows for controlled, non-invasive measurement of sun protection factors across UVA, UVB, visible, and infrared ranges, using polychromatic LEDs and pulse modulation to minimize radiation dose and provide uniform illumination, enabling accurate determination without causing harm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If UV radiation is used to determine SPF through erythema induction, then measurement accuracy is improved, but harm to test subjects increases
Solution Approach 1:
The patent introduces an intermediary substance (eosin) that binds to skin proteins and exhibits photochemical changes when exposed to UV radiation. This intermediary allows the measurement of UV protection without directly measuring harmful erythema effects on the skin, thus maintaining measurement accuracy while reducing harm to test subjects.
Solution Approach 2:
The patent replaces the biological/physiological measurement system (erythema induction on human skin) with a photochemical measurement system (eosin binding and spectral analysis). This substitution eliminates the need to expose human skin to harmful UV doses while preserving the ability to measure sun protection factor accurately.
2Adaptability or versatility
If multiple separate radiation sources are used to cover wide spectral range, then measurement versatility is improved, but device complexity increases
Solution Approach 1:
The patent divides the spectral range into multiple segments, each covered by a dedicated radiation source optimized for that range. This segmentation allows each source to operate at peak efficiency in its designated wavelength range, achieving comprehensive spectral coverage while maintaining manageable system complexity through functional specialization.
Solution Approach 2:
The patent creates a universal measurement system where multiple radiation sources share common control and detection infrastructure. The system can measure SPF across UVA, UVB, and visible ranges using a single integrated platform, making the device versatile for various sunscreen testing requirements without requiring separate specialized equipment for each spectral range.
3Object-affected harmful factors
If polychromatic LEDs with pulse modulation are used, then radiation dose to test subjects is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent employs periodic pulse modulation of the LED radiation sources, delivering UV radiation in controlled bursts rather than continuous exposure. This periodic action reduces the cumulative radiation dose to test subjects while the precise timing and intensity control of the pulses maintain sufficient signal strength for accurate SPF measurement through the eosin photochemical response.
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
The system allows for precise, non-invasive determination of sun protection factors across a wide spectral range, reducing skin stress and providing high-quality analysis results, aligning in-vivo and in-vitro testing and enabling measurement of photodegradation.
Implementation Method 1
a spectrometer (13) which is suitable and provided for detecting light reflected by a sample body (3)
Implementation Method 2
a beam source device (12) having a plurality of beam sources (12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8), wherein the wavelength spectra of at least two of the beams emitted by the separate beam sources (12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8) differ from one another
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The invention comprises a method for determining the sun protection factors of sunscreens, including the acquisition, filtering, and processing of wavelength-dependent signals, which enables the advantageous calculation of the signals. In this method, radiation with different wavelength spectra is emitted from two or more separate radiation sources of the radiation source device. The invention further relates to a measuring system for carrying out the method.