Blood Fluidity Evaluation Using Pulse-Synchronized Optical Detection
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Solution Overview
Problem
Current methods for evaluating blood viscosity are invasive, inconvenient, and lack sensitivity due to difficulties in distinguishing between arterial and capillary systems, and in accounting for blood pressure pulsations, leading to inclusion of unnecessary information in measurement data.
Innovation Solution
A device with a pressure member equipped with light emission and reception elements that allows for precise evaluation of blood fluidity by synchronizing measurements with the subject's pulse, optimizing the test site position, and focusing on capillary system data to reduce measurement errors and enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If blood flow measurement is performed by optically detecting blood returning to a predetermined site after pressure is removed, then blood flow data can be obtained, but it becomes difficult to distinguish between arterial system and capillary system data, reducing measurement precision
Solution Approach 1:
The patent segments the blood flow measurement process into distinct phases: pressurization phase, holding phase, and release phase. By analyzing blood flow characteristics during specific time windows within these phases, the method isolates capillary system data from arterial system data. The capillary blood flow is measured during the release phase when arterial pressure pulsations have subsided, thereby achieving precise evaluation of blood viscosity without contamination from arterial flow information.
2Reliability
If pressure is applied to empty the predetermined site of blood, then blood return amount can be detected, but blood pressure influence and pulsation components are introduced, making calibration difficult and reducing measurement reliability
Solution Approach 1:
The patent applies preliminary action by maintaining a constant pressurization phase before the release phase. During this pressurization and holding period, the arterial system is emptied and stabilized, and the baseline blood pressure effects are established. By then transitioning to the release phase for measurement, the method eliminates variable blood pressure pulsation components while maintaining reliable calibration conditions. This preliminary stabilization ensures that subsequent measurements reflect only capillary blood flow characteristics.
3Measurement precision
If the pressure member has larger dimensions to cover the test site, then measurement can be performed, but compression of peripheral regions occurs, introducing measurement errors
Solution Approach 1:
The patent applies local quality by designing the pressure member with a focused, localized contact surface that applies pressure precisely to the predetermined measurement site. The pressure distribution is concentrated at the target location rather than dispersed across a large area. This localized pressure application ensures that only the intended measurement region is compressed, while peripheral regions remain unaffected, thereby eliminating measurement errors caused by peripheral compression and maintaining high measurement precision.
4Device complexity
If light emission and reception elements are integrated on the pressure member, then device complexity is reduced, but the dimensions of the pressure member must be minimized, making precise positioning more difficult
Solution Approach 1:
The patent merges the pressure member with light emission and reception elements into a single integrated measurement probe. This combination allows simultaneous application of pressure and optical measurement at the same location, simplifying the overall device structure. The integrated design ensures that the optical elements are positioned exactly where pressure is applied, eliminating alignment errors between separate pressure and measurement components, thereby achieving both device simplicity and measurement precision.
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 convenient, sensitive evaluation of blood fluidity by minimizing measurement errors related to compression and pulse, and effectively isolating capillary system data for accurate viscosity assessment.
Implementation Method 1
a light emission element 11 and a light reception element 12 which are installed upon the pressure member 10, wherein the light emission element 11 is adapted to irradiate light to the test site 100 against which the pressure member 10 is pressed, and the light reception element 12 is adapted to receive the light from the test site 100
Data Source
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AI summary
In order to supply a method and a device that can evaluate the fluidity (viscosity) of blood with good sensitivity in a simple manner, there is provided a blood fluidity evaluation method in which a pressure member is pressed against a test site upon a test subject e.g.a fingertip, blood at the test site is squeezed to flow out to the periphery of the test site, change over time of the amount of blood at the test site is measured at this time using optical scattering, and blood fluidity at the test site is evaluated from this measurement data; and, desirably, before the above method, a positioning process is performed in which: the pressure member is pressed against the test site with a weak force; pulse measurement data is acquired due to the absorption of light; and a relative position, at which the intensity of the pulse measurement data attains a local maximum, is determined as being an optimum measurement position. Pulse measurement data measured at a different site can be used to improve calculation accuracy.