Multi-Angle Optical Tissue Scattering Detection System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current non-invasive optical systems for medical applications face challenges in accurately measuring oxygen saturation and pulse rate from tissue due to limitations in detecting light scattered at multiple angles, which affects the precision of health assessments.
Innovation Solution
An optical system comprising a light source and multiple photodetectors positioned at various angles to produce full scattering profiles, allowing for the identification of an iso-pathlength point to extract light intensity and calculate oxygen saturation and pulse rate, using a combination of continuous wave lasers and photodetectors like silicon-type and Gallium Arsenide detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single photodetector is used to detect scattered light, then the device complexity is reduced, but the measurement precision of oxygen saturation and pulse rate deteriorates due to inability to capture full scattering profile
Solution Approach 1:
The detection system is segmented into multiple photodetectors positioned at different angles (including 0°, 45°, 90°, and 135°) to capture scattered light from different directions. This segmentation allows construction of complete scattering profiles at multiple angles, which improves the precision of oxygen saturation and pulse rate measurements by providing more comprehensive optical information about the tissue.
Solution Approach 2:
The system transitions from single-point detection to multi-angular detection by arranging photodetectors in different spatial dimensions around the tissue sample. This dimensional expansion enables collection of scattering profiles at multiple angles simultaneously, transforming the measurement from a single value to a comprehensive angular distribution that enhances measurement precision.
2Measurement precision
If multiple photodetectors are positioned at various angles to capture full scattering profile, then the measurement precision improves, but the device complexity and alignment difficulty increase
Solution Approach 1:
The photodetectors are pre-positioned at specific standard angles (0°, 45°, 90°, 135°) relative to the light source and tissue geometry. This preliminary arrangement of detectors at predetermined angular positions simplifies the measurement process by eliminating the need for dynamic angular adjustment during measurement, thereby reducing operational complexity while maintaining high measurement precision for pulse rate and oxygen saturation.
3Measurement precision
If light beam is centered on axis parallel to tissue, then the scattering profile coverage is improved, but the optical path length varies significantly affecting measurement accuracy
Solution Approach 1:
The system performs preliminary identification of the iso-pathlength point (IPLP) in the scattering profile before conducting oxygen saturation measurements. By pre-locating the specific angular position where optical path length is constant, the system ensures that subsequent measurements are taken at a stable path length, eliminating variability and improving the precision of light intensity extraction and derived physiological parameters.
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 system enables accurate and robust measurements of oxygen saturation and pulse rate, with standard deviations comparable to medical pulse oximetry devices, and can also assess blood pressure, respiratory rate, perfusion, and blood sugar levels, as well as the quality of scattering liquids.
Implementation Method 1
detecting light scattered from tissue
Implementation Method 2
light interacted with tissue is perturbed in a manner that can be detected and quantified
Implementation Method 3
a plurality of photodetectors/cameras placed at multiple angles with respect to the tissue for collecting the light scattered from the tissue
Data Source
AI summary
A system for detecting light scattered from a tissue and for finding an IPL point for extracting oxygen saturation and pulse rate comprises: (a) at least one light source for illuminating a tissue, the at least one light source has a beam alignable to pass through the tissue; and (b) a plurality of photodetectors/cameras placed at multiple angles with respect to the tissue for collecting the light scattered from the tissue at multiple angles at the same time. The beam of the light source is centered either on a first axis parallel to the tissue and/or on a second axis with respect to the tissue, and the plurality of the photodetectors/cameras are either stationary or movable for conducting measurements at multiple angles for producing a first full scattering profile (FSP) and a second FSP applicable or finding the IPL point for extracting the oxygen saturation and the pulse rate.