Handheld Tissue Oximetry Device Using Spatially-Resolved Spectroscopy
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Solution Overview
Problem
Current oximeters, particularly those using continuous wave spectroscopy, face limitations in accuracy for intraoperative tissue monitoring due to assumptions about tissue scattering, struggle with local measurements, and are often bulky and expensive, failing to provide absolute oxygen saturation measurements quickly and reliably under non-ideal conditions.
Innovation Solution
A compact, handheld tissue oximetry device employing spatially-resolved spectroscopy with a circular arrangement of light sources and detectors, allowing for robust calibration and self-correction, which measures oxygen saturation independently from tissue scattering, enabling absolute measurements of oxygenated and deoxygenated hemoglobin concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If continuous wave spectroscopy is used for tissue oximetry, then the device can measure oxygen saturation, but measurement accuracy deteriorates under non-ideal conditions due to assumptions about tissue scattering
Solution Approach 1:
The patent changes the measurement parameters from single-wavelength or simple ratio measurements to multi-wavelength spatially-resolved spectroscopy. By measuring at multiple wavelengths and multiple source-detector distances, the system can independently determine tissue scattering properties and absorption properties, eliminating the need for assumptions about tissue scattering and improving measurement accuracy under non-ideal conditions.
Solution Approach 2:
The patent introduces spatial resolution as an intermediary parameter. By measuring light attenuation at multiple source-detector distances, the system can separate the effects of tissue scattering from absorption. This spatial information acts as a mediator that allows independent determination of tissue optical properties, improving measurement reliability without requiring assumptions about tissue scattering.
2Measurement precision
If spatially-resolved spectroscopy is implemented, then absolute oxygen saturation measurements can be obtained independently from tissue scattering, but device complexity increases
Solution Approach 1:
The patent segments the measurement system into multiple discrete wavelength channels and multiple source-detector distance pairs. Each segment (wavelength-distance combination) provides independent information about tissue optical properties. This segmentation allows the complex problem of determining absolute oxygen saturation to be broken down into simpler independent measurements that can be processed separately and combined.
Solution Approach 2:
The patent adds the spatial dimension (source-detector distance) to the spectral measurements. By incorporating measurements at multiple distances in addition to multiple wavelengths, the system creates a two-dimensional measurement space that provides sufficient independent equations to solve for multiple unknown tissue optical properties, including absolute oxygen saturation, without requiring complex additional hardware.
3Reliability
If multiple source-detector distances are used for spatially-resolved spectroscopy, then robust calibration and self-correction are enabled, but device size increases
Solution Approach 1:
The patent designs the probe with a circular arrangement of light sources and detectors that serves multiple functions simultaneously. The same circular array enables spatially-resolved spectroscopy at multiple distances, provides robust calibration through geometric symmetry, and allows self-correction of measurement errors. This universal design achieves multiple goals with a single structural configuration, avoiding the need for separate calibration devices or correction mechanisms.
Solution Approach 2:
The patent employs a circular (curved) arrangement of light sources and detectors around the probe tip. This curved geometry naturally provides multiple source-detector distances while maintaining a compact form factor. The circular symmetry also simplifies calibration by ensuring uniform geometric relationships in all directions, and enables self-correction through redundant measurement paths, all within a small probe volume.
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 device provides accurate, absolute oxygen saturation measurements in both regional and local tissue areas, including during surgery, with improved precision and portability, addressing the limitations of existing technologies by using spatially-resolved spectroscopy to determine tissue oxygen levels.
Implementation Method 1
Light is emitted from one or more lighting elements into the tissue and at least some of the light is reflected back by the tissue
Implementation Method 2
Tissue oximeters can measure oxygen levels in human tissue by exploiting these light-absorption differences
Implementation Method 3
Light absorption differs significantly for oxygenated and deoxygenated hemoglobins at certain wavelengths of light
Data Source
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AI summary
A system includes an enclosure having a processor and a memory coupled to the processor. The enclosure includes a display coupled to the processor where the display is visible from an exterior of the enclosure; and a battery within the enclosure coupled to the processor and the display. The enclosure includes a probe tip coupled to an exterior of the enclosure. The probe tip includes first, second, and third sensor openings. A first distance between the first and second sensor openings is different than a second distance between the first and third sensor openings. The enclosure includes code stored in the memory where the code is executable by the processor, and includes code to receive first data associated with the first and second sensor openings, code to receive second data associated with the first and second sensor openings, and code to perform SRS using the first and the second data.