Inner Light Layer Illumination for Turbid Media Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Imaging in turbid media, such as human tissues and seawater, is severely limited by strong absorption and scattering, which attenuate optical wave intensity and produce noise, restricting imaging depth and distance in medical and underwater applications.
Innovation Solution
The method of inner light layer illumination using multi-beam interference, where a short light pulse is broadened by negative dispersion and then compressed by positive dispersion in the turbid medium, creating a thin inner light layer to reduce absorption and scattering, enhancing signal intensity and depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high incident light intensity is used to increase signal strength, then the number of remaining photons increases, but the human tissues are damaged
Solution Approach 1:
The light propagation path is segmented into multiple thin layers through multi-beam interference, creating discrete illumination planes at different depths. This segmentation allows the light energy to be distributed across multiple focal planes rather than concentrated in a single high-intensity beam, reducing peak intensity while maintaining total signal strength.
Solution Approach 2:
The patent changes the temporal and spatial parameters of light propagation by using ultra-short pulsed light and creating time-gated interference patterns. This transforms the continuous high-intensity illumination into brief, controlled pulses that achieve sufficient signal strength during the pulse duration while minimizing cumulative tissue exposure and damage.
2Length of stationary object
If traditional optical imaging is used in turbid media, then imaging can be performed, but the imaging depth is limited to less than 1 cm due to absorption and scattering
Solution Approach 1:
The imaging depth is segmented into multiple thin illuminated layers through multi-beam interference, allowing sequential imaging at different depths. Each layer is illuminated independently with optimized intensity, enabling deep tissue imaging while maintaining signal quality by focusing energy only at the current imaging plane rather than throughout the entire path.
Solution Approach 2:
The patent uses periodic ultra-short light pulses to illuminate successive layers at different depths. By timing the detection to coincide with each pulse and using time-gating, the system achieves periodic sampling of different depth layers, building up a complete deep-tissue image through multiple periodic cycles while maintaining high signal-to-noise ratio for each layer.
3Length of stationary object
If multiple light beams are used to illuminate different layers, then imaging depth increases, but the device complexity increases
Solution Approach 1:
A single ultra-short pulsed light source performs multiple functions: it provides the temporal gating for depth resolution, generates the interference patterns for layer segmentation, and serves as the illumination for all depth layers through spectral broadening. This universal light source replaces what would otherwise require multiple separate illumination systems for different depths.
Solution Approach 2:
The dispersive medium itself (turbid tissue) provides the frequency-dependent phase delays that create the multi-beam interference pattern. The system uses the inherent optical properties of the tissue rather than requiring external optical elements to create the layering effect, allowing the tissue to participate actively in generating the illumination structure.
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
This approach significantly increases imaging depth in human tissues to over 5 cm and distance in seawater to over 100 m, with potential to reach 20 cm in the body and 2000 m in clear water, while improving signal-to-noise ratio and reducing light noise.
Implementation Method 1
inner light layer illumination by multi-beam interference
Implementation Method 2
a short light pulse is broadened by negative dispersion
Implementation Method 3
compressed by positive dispersion in the turbid medium, creating a thin inner light layer
Implementation Method 4
strong absorption and scattering of turbid media, which attenuate optical or acoustic wave intensity
Implementation Method 5
strong absorption and scattering of turbid media, which attenuate optical or acoustic wave intensity
Data Source
AI summary
The invention relates to an apparatus of inner light layer illumination for optical imaging in turbid media. This apparatus comprises laser generating short light pulse(s), negative dispersion device to broaden the width of the short light pulse(s) before the pulse(s) enter(s) the turbid medium, imaging distance adjuster changing the imaging distance and optical receiver receiving returned signal light pulse(s). This apparatus can reduce absorption and scattering of the turbid media greatly and create an inner light layer with strong intensity to illuminate the object in the turbid medium. The mathematical calculations have proved that this apparatus can enhance the signal strength by more than 600 dB. The imaging depth can be over 5 cm in human body, and more than 500 m in clear seawater. The imaging resolutions are <1 micrometer along object plane and are approximate 1 micrometer along direction of depth of field.