Blood Flow Sensor Using Multi-Wavelength Segmentation to Cancel Oxygen Saturation
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Solution Overview
Problem
Conventional blood flow measuring apparatuses struggle to accurately measure brain and muscle activity due to the influence of oxygen saturation changes, which affect the optical absorption and scattering of light by hemoglobin in red blood cells, leading to inaccurate measurements of blood flow.
Innovation Solution
A blood flow measuring apparatus with a sensor unit comprising a light emitting part and multiple light receiving parts arranged at different distances, using arithmetic processing to cancel out the component of oxygen saturation from the signals, allowing for accurate measurement of blood flow independent of oxygen saturation levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional light transmitting method is used to measure blood flow, then the measurement can be performed, but the measurement accuracy is reduced due to oxygen saturation changes affecting light absorption
Solution Approach 1:
The patent segments the light receiving process into multiple wavelength channels, each detecting different aspects of light absorption. By dividing the measurement into multiple spectral components, the system can separately analyze and eliminate the oxygen saturation effect from the blood flow measurement, thereby resolving the contradiction between measurement capability and measurement accuracy.
Solution Approach 2:
The patent changes the measurement parameter from single-wavelength light transmission to multi-wavelength light transmission. By using multiple wavelengths, the system can distinguish between absorption caused by oxygen saturation and absorption caused by blood flow, thus eliminating the harmful influence of oxygen saturation changes on measurement accuracy.
2Device complexity
If single light receiving part is used, then the device structure is simple, but the measurement is influenced by both red blood cell density and oxygen saturation
Solution Approach 1:
The patent segments the light receiving function into multiple wavelength-specific detectors. This segmentation allows the system to measure different optical properties simultaneously, enabling the separation of oxygen saturation effects from blood flow effects while maintaining a relatively compact sensor structure.
Solution Approach 2:
The patent makes the sensor unit multi-functional by incorporating multiple light receiving parts that can detect different wavelengths. This universal sensor can simultaneously measure both oxygen saturation and blood flow parameters, eliminating the need for separate measurement systems and resolving the contradiction between device simplicity and measurement accuracy.
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
Enables precise measurement of blood flow and brain activity by isolating the effect of oxygen saturation, providing accurate data on red blood cell concentration and hematocrit levels, thus improving the accuracy of brain and muscle activity assessments.
Implementation Method 1
a sensor unit including a light emitting part configured to emit light onto a measurement area and a light receiving part configured to receive the light transmitted through the measurement area
Implementation Method 2
hemoglobin (Hb) included in red blood cells has a property to absorb and scatteringly reflect light
Implementation Method 3
hemoglobin (Hb) included in red blood cells has a property to absorb and scatteringly reflect light
Data Source
AI summary
A blood flow measuring apparatus includes a sensor unit including a light emitter configured to emit light onto a measurement area and a light receiver configured to receive the light transmitted through the measurement area; at least one more light receiver configured to receive the light transmitted through the measurement area; and a control part configured to measure a blood flow state of the measurement area according to signals outputted by the light receivers. The light emitted by the light emitter is received by the light receivers arranged at different distances from the light emitter and the light receivers output the signals responsive to the received light. The control part measures the blood flow state of the measurement area by performing an arithmetic process to cancel a component of oxygen saturation in the blood, said component being included in the signals outputted by the light receivers.