NIR Tissue Oxygenation Instrument Using Water Absorption Peak
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Solution Overview
Problem
Current non-invasive methods for measuring tissue oxygenation, such as NIRS, face challenges in accurately quantifying oxygenated and deoxygenated hemoglobin concentrations and providing precise, cost-effective measurements, especially for muscle tissue, with existing technologies being complex and prone to errors due to tissue heterogeneity and limitations in measuring absolute concentrations.
Innovation Solution
A non-invasive optoelectronic instrument utilizing the absorption peak method at 980 nm wavelength, combined with a hardware and software system, measures the characteristic optical absorption in the NIR spectrum to calculate absolute concentrations of oxygenated and reduced hemoglobin, enabling precise oxygenation/saturation measurements and trend analysis, including lactic acid accumulation indicators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If continuous wave (CW) NIRS instrumentation is used, then device complexity is reduced, but measurement precision deteriorates because absolute concentrations of oxygenated and reduced hemoglobin cannot be directly measured
Solution Approach 1:
The patent introduces water absorption peak at 980 nm as an intermediary reference marker. By measuring water absorption (which has known concentration in tissue) at this specific wavelength, the system can indirectly determine scattering coefficients and then calculate absolute hemoglobin concentrations. This intermediary approach allows CW instrumentation to achieve quantitative measurements without requiring complex modulated or time-domain systems.
Solution Approach 2:
The patent changes the measurement approach by utilizing the water absorption peak parameter at 980 nm instead of relying solely on hemoglobin absorption peaks. This parameter change enables the system to extract scattering information from water absorption data, which then allows calculation of absolute hemoglobin concentrations using the diffusion equation, resolving the limitation of CW systems.
2Measurement precision
If multi-distance systems are used to achieve quantitative measurement, then measurement precision improves, but reliability deteriorates due to errors from heterogeneous tissue structure
Solution Approach 1:
The patent uses water absorption peak at 980 nm as an intermediary that provides a reliable reference for scattering coefficient calculation. By anchoring the measurement to this known water absorption peak, the system can compensate for tissue heterogeneity effects and achieve both quantitative precision and reliability across different tissue types and measurement distances.
3Measurement precision
If derivative systems are used to eliminate scattering contribution, then measurement precision improves for oxygenation ratio, but manufacturing precision deteriorates because absolute concentration cannot be measured
Solution Approach 1:
The patent introduces water absorption peak as an intermediary that enables simultaneous determination of both scattering coefficients and absolute hemoglobin concentrations. By measuring water absorption at 980 nm, the system obtains reference values that allow calculation of scattering coefficients, which when combined with hemoglobin absorption measurements, enable both oxygenation ratio and absolute concentration measurements without requiring derivative operations that eliminate scattering effects.
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 instrument provides real-time, precise, and cost-effective quantification of tissue oxygenation and hemoglobin concentrations, overcoming previous limitations by using multiple wavelengths and advanced data processing to achieve accurate and reliable measurements, with the ability to monitor oxygenation trends and lactic acid accumulation during physical activity.
Implementation Method 1
measuring, with the optical receiver, the light transmitted by the tissue at said wavelengths; said instrument being able to evaluate the characteristic optical absorption of a material at certain wavelengths belonging to the near infrared spectrum
Implementation Method 2
The NIRS (Near InfraRed Spectroscopy), that consists in illuminating a tissue with a light source with wavelengths in the near infrared spectral range (600-1000nm), in detecting the light diffused by the tissue by means of a receiver
Implementation Method 3
A non-invasive optoelectronic instrument utilizing the absorption peak method at 980 nm wavelength, combined with a hardware and software system, measures the characteristic optical absorption in the NIR spectrum to calculate absolute concentrations of oxygenated and reduced hemoglobin
Data Source
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AI summary
An instrument for the measurement of the oxygenation/saturation of biological tissue comprising at least one optical source generating continuous intensity luminous radiation, an optical probe to convey the radiations onto a part of the tissue and to collect the radiations in exit from the tissue at a set distance, a receiver unit and an electronic control unit. The instrument is adapted to interface to a personal computer in order to obtain indicative absolute levels of the oxygenation of the tissue based on the collected signals. The optical source is made up of at least three independent optical modules for the emission of the same number of different luminous radiations with wavelengths belonging to the near infrared spectrum, with at least one of said wavelengths in correspondence to a water absorption peak.