A capillary refill detection device and method based on diffuse correlation spectroscopy

Abstract

The application discloses a capillary refill detection device and method based on diffuse correlation spectroscopy, and relates to the technical field of medical devices.The device comprises a probe structure, a near-infrared light source, a light signal receiving and computing module, and a control and data computing and storage module.The probe structure comprises a transmitting optical fiber and multiple groups of receiving optical fibers.The transmitting optical fiber is connected with the near-infrared light source and used for transmitting near-infrared light to the measured tissue.The distance between each group of receiving optical fibers and the transmitting optical fiber is different, and each group of receiving optical fibers is used for receiving the light signal scattered back from the measured tissue.The light signal receiving and computing module is used for receiving the light signal transmitted by each receiving optical fiber and obtaining the intensity autocorrelation function of each scattered light.The control and data computing and storage module is used for calculating the blood flow index of the tissue at a corresponding depth according to the intensity autocorrelation function of each scattered light, fitting the blood flow index-time curve, and then obtaining the capillary refill time at each depth.The application can synchronously obtain the CRT parameters of multiple layers of tissue by means of a multi-interval optical fiber array design, so that the difference between the microcirculation states of the shallow layer and the deep layer can be accurately distinguished.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a capillary refill detection device and method based on diffusion correlation spectroscopy. Background Technology

[0002] Currently, CRT (Capillary Refill Time) measurement relies on doctors' visual observation of the skin's color recovery time after pressure, which is highly subjective (error > ±0.5 seconds) and cannot quantify the state of deep microcirculation. Existing optical devices (such as laser Doppler) can only measure single-point blood flow and lack depth resolution.

[0003] Among related technologies, diffusion correlation spectroscopy (DCS) involves irradiating the tissue surface with near-infrared light (650-900 nm). This near-infrared light is strongly scattered by moving scatterers during transmission to biological samples. This scattering causes a phase change in the near-infrared coherent scattered light field, which can be detected by a detector. Measurement of this spot fluctuation allows for the assessment of erythrocyte motility in the microcirculation. By calculating the autocorrelation function of the scattered light intensity, changes in regional blood flow (RBF) can be deduced. This technique enables non-invasive, real-time monitoring of tissue microcirculation, thus providing quantitative data for CRT (Continuous Respiratory Therapy) detection.

[0004] However, conventional DCS probes use a fixed transmit-receive fiber spacing, which can only reflect blood flow information of a single tissue depth. They cannot distinguish the differences in blood flow recovery dynamics between superficial papillary capillaries and deep subcutaneous tissues or arteriovenous plexuses. This leads to the neglect of deep microcirculatory disturbances in diseases such as shock and diabetic foot, affecting the accuracy and timeliness of clinical diagnosis. Summary of the Invention

[0005] This invention provides a device and method for detecting capillary refilling based on diffusion correlation spectroscopy, which can solve the technical problem in the prior art that it is impossible to simultaneously obtain the refilling time of capillaries in multiple tissue depths.

[0006] In a first aspect, the present invention provides a capillary refill detection device based on diffusion correlation spectroscopy, the device comprising: The probe structure includes a transmitting optical fiber and multiple sets of receiving optical fibers. The transmitting optical fiber is connected to a near-infrared light source and is used to transmit near-infrared light to the tissue being tested. Each set of receiving optical fibers is at a different distance from the transmitting optical fiber and is used to receive the light signal scattered back from the tissue being tested. The optical signal receiving and calculation module is used to receive the optical signals transmitted by each receiving optical fiber and obtain the autocorrelation function of the intensity of each scattered light. The control and data calculation and storage module is used to calculate the blood flow index of the tissue at the corresponding depth based on the autocorrelation function of the light intensity of each scattered light, and to fit the blood flow index versus time curve to obtain the capillary refill time at each depth.

[0007] In conjunction with the first aspect, in one embodiment, the aforementioned plurality of receiving optical fibers includes three sets of receiving optical fibers, which are respectively located at distances r1, r2, and r3 from the aforementioned transmitting optical fibers, wherein r1 <r2<r3; Each receiving fiber consists of multiple fiber bundles, with each fiber bundle evenly arranged around the aforementioned transmitting fiber.

[0008] In conjunction with the first aspect, in one embodiment, each set of receiving optical fibers includes at least four fiber bundles, with the fiber bundles of adjacent sets of receiving optical fibers being staggered.

[0009] In conjunction with the first aspect, in one embodiment, the aforementioned control and data calculation and storage module is further used to perform weighted fusion of the refill times of each capillary to obtain an average capillary refill time. Among them, the distance between the receiving optical fiber and the transmitting optical fiber is inversely proportional to the weight of the corresponding capillary refill time.

[0010] In conjunction with the first aspect, in one implementation, the weight of the k-th capillary refill time... for: k=1,2,3; in, Let be the distance between the receiving fiber and the transmitting fiber in the k-th group.

[0011] In conjunction with the first aspect, in one embodiment, the probe structure further includes: Multiple light-blocking rings are provided, the number of which is the same as the number of receiving optical fibers. Each light-blocking ring is placed between the transmitting optical fiber and the innermost receiving optical fiber, as well as between each pair of adjacent receiving optical fibers.

[0012] In conjunction with the first aspect, in one embodiment, the probe structure is provided with a pressure mechanism; The aforementioned control and data calculation and storage module is also used to control the pressure mechanism to apply controllable pressure to the tissue being tested.

[0013] Secondly, the present invention provides a detection method based on the above-mentioned capillary refill detection device, the method comprising: Near-infrared light is emitted into the tissue under test by transmitting optical fiber, and light signals scattered back from different depths of the tissue under test are simultaneously received by multiple sets of receiving optical fibers. The optical signal receiving and computing module receives the optical signals transmitted by each receiving optical fiber and obtains the autocorrelation function of the intensity of each scattered light. The control and data calculation and storage module calculates the blood flow index of the corresponding tissue depth based on the autocorrelation function of each scattered light intensity, and fits the blood flow index versus time curve to obtain the capillary refill time at each depth.

[0014] In conjunction with the second aspect, in one implementation, the capillary refill time at each depth is obtained, specifically including: Based on the blood flow index and time curves, the time interval from pressure release to the first recovery of the blood flow index to the level before pressure application at each depth was determined as the capillary refill time at each depth.

[0015] In conjunction with the second aspect, in one embodiment, after obtaining the capillary refill time at each depth, the method further includes: The weight of capillary refill time at each depth is determined based on the distance between the receiving fiber and the transmitting fiber in each group; the distance between the receiving fiber and the transmitting fiber is inversely proportional to the weight of the corresponding capillary refill time. Based on the weight of capillary refill time at each depth, the refill times of each capillary are weighted and fused to obtain the average capillary refill time.

[0016] The beneficial effects of the technical solutions provided by the embodiments of the present invention include: By integrating multiple sets of receiving optical fibers at different distances within a single probe through a multi-spacing fiber array design, it is possible to simultaneously acquire CRT parameters of multi-layer tissues, thereby accurately distinguishing the differences between superficial and deep microcirculation states, achieving a comprehensive assessment of the human microcirculation status, improving the accuracy and reliability of clinical diagnosis, having significant clinical application value and broad market prospects, and solving the technical problem in related technologies that cannot simultaneously acquire the refill time of capillaries in multi-depth tissues. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the technical principle of diffusion-related spectroscopy (DCS) in an embodiment of the present invention; Figure 2 This is a schematic diagram of the functional modules of an embodiment of the capillary refill detection device of the present invention; Figure 3 This is a schematic diagram of the probe structure in an embodiment of the present invention; Figure 4 This is a graph showing the blood flow index versus time in an embodiment of the present invention; Figure 5 This is a schematic flowchart of an embodiment of the detection method of the present invention; Figure 6 This is a schematic diagram of the display and interaction module's display interface in an embodiment of the present invention.

[0018] In the picture: 1. Probe structure; 11. Transmitting optical fiber; 12. Receiving optical fiber; 121. First receiving optical fiber; 122. Second receiving optical fiber; 123. Third receiving optical fiber; 13. Light-blocking ring; 2. Tissue under test; 3. Optical signal receiving and calculation module; 4. Control and data calculation and storage module; 5. Display and interaction module; 6. Laser; 7. Light source adjustment module. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In a first aspect, embodiments of the present invention provide a capillary refill detection device based on diffusion correlation spectroscopy.

[0021] This invention is based on diffusion-related spectroscopy, and its theoretical foundation mainly includes the dynamic light scattering principle and the diffusion and propagation characteristics of photons in biological tissues, which are described in detail below: 1. Dynamic light scattering: When a laser beam irradiates a moving red blood cell, the phase of the scattered light changes randomly due to the movement of the red blood cell (Brownian motion or directional flow), causing the intensity of the emitted light I(t) to fluctuate over time. The time scale of this fluctuation is related to the speed of the red blood cell movement.

[0022] 2. Photon diffusion theory: In highly scattering media such as biological tissues, photons propagate through diffusion after multiple scattering events. The average path length and distribution of photons are described by the diffusion equation, providing a theoretical basis for modeling dynamic scattering signals.

[0023] like Figure 1 As shown, a laser is used as the light source, and after being optimized by a collimator, it is transmitted to biological samples via multi-mode fiber. The light scattered by the biological samples, i.e., the scattered light, is received by a single-mode fiber and then transmitted to an avalanche photodiode (APD).

[0024] By measuring the change in scattered light intensity over time on the sample surface, we can obtain information about the motion of the scattering particles. The autocorrelation function of the light intensity can be expressed as: .

[0025] In the formula, I(t) is the light intensity at time t, representing the average value over a certain integration time, and I(t+τ) is the light intensity at time t+τ.

[0026] In practical experiments or commercial products, light intensity is usually easier to obtain than electric field strength. Furthermore, to eliminate the influence of the absolute value of the collected light intensity, a normalized second-order light intensity autocorrelation function is used in the DCS to describe the correlation between red blood cell flow and time. Therefore, the measured light intensity normalized autocorrelation function... It can be represented as: .

[0027] Then, through the Siegfried relation, the expression for the DCS autocorrelation function can be derived, and the result simplifies to: .

[0028] Wherein, β represents the system coherence factor, which reflects the system signal-to-noise ratio (ideally close to 1). Indicates the mean free path of the photon Parameters related to the scattering coefficient; <v 2 The root mean square of red blood cell velocity directly represents blood flow velocity.

[0029] Based on the actual measured data of the system, the g2(τ) curve can be fitted using the nonlinear least squares method, and then the derivative of g2(τ) can be calculated: .

[0030] The derivative of g2(τ) reflects the rate of decay of g2(τ): <v 2 The larger the value of the derivative, the greater its magnitude, which indicates that the autocorrelation function decays quickly and the blood flow velocity is high, and vice versa.

[0031] Therefore, when τ->0: .

[0032] Blood flow index (BFI) refers to the combined effect of photon path length and red blood cell velocity per unit time. BFI is directly proportional to blood flow velocity and is a commonly used semi-quantitative indicator in clinical practice.

[0033] .

[0034] Therefore, the relationship between blood flow index and time within the tissue is established. By fitting the relationship between blood flow index and time into a curve and combining it with a compression device, CRT parameters can be measured.

[0035] In one embodiment, reference is made to Figure 2, Figure 2 This is a functional module diagram of an embodiment of the capillary refill detection device based on diffusion correlation spectroscopy of the present invention. The above-mentioned capillary refill detection device includes a probe structure 1, an optical signal receiving and calculation module 3, and a control and data calculation and storage module 4. like Figure 3 As shown, the probe structure 1 includes a transmitting optical fiber 11 and multiple sets of receiving optical fibers 12. The transmitting optical fiber 11 is connected to a near-infrared light source and is used to transmit near-infrared light to the tissue under test 2. Each set of receiving optical fibers 12 is at a different distance from the transmitting optical fiber 11 and is used to receive the light signal scattered back from the tissue under test.

[0036] The aforementioned optical signal receiving and calculation module 3 is used to receive the optical signals transmitted by each receiving optical fiber 12 and obtain the autocorrelation function of the intensity of each scattered light.

[0037] The aforementioned control and data calculation and storage module 4 is used to calculate the blood flow index of the corresponding tissue depth based on the autocorrelation function of each scattered light intensity, and to fit the blood flow index versus time curve. Furthermore, based on the blood flow index versus time curve, the capillary refill time at each depth is obtained. The blood flow index versus time curve is the curve showing the change of the blood flow index over time.

[0038] In this embodiment, the corresponding depth of tissue refers to the tissue depth level corresponding to each receiving optical fiber. The receiving optical fiber with a smaller distance from the transmitting optical fiber corresponds to a shallower tissue level, while the receiving optical fiber with a larger distance corresponds to a deeper tissue level.

[0039] In this embodiment, by using a multi-spacing fiber array design, multiple sets of receiving fibers at different distances are integrated into a single probe, which can simultaneously acquire CRT parameters of multi-layer tissues, thereby accurately distinguishing the differences between superficial and deep microcirculation states, realizing a comprehensive assessment of the human microcirculation status, improving the accuracy and reliability of clinical diagnosis, having significant clinical application value and broad market prospects, and solving the technical problem in related technologies that cannot simultaneously acquire the capillary refill time of multi-depth tissues.

[0040] In one embodiment, the probe structure 1 includes a transmitting optical fiber 11 and at least two sets of receiving optical fibers 12 with different spacings.

[0041] Based on the above embodiments, in this embodiment, the multiple sets of receiving optical fibers 12 include three sets of receiving optical fibers, and the distances between the three sets of receiving optical fibers and the transmitting optical fiber 11 are r1, r2 and r3 respectively, wherein r1 <r2<r3。

[0042] Each receiving fiber optic cable 12 includes multiple fiber bundles. Each fiber bundle in each receiving fiber optic cable 12 is evenly arranged around the transmitting fiber optic cable 11, and each fiber bundle is at the same distance from the transmitting fiber optic cable 11.

[0043] Optionally, the three sets of receiving optical fibers are designated as a first receiving optical fiber 121, a second receiving optical fiber 122, and a third receiving optical fiber 123. The distance between the first receiving optical fiber 121 and the transmitting optical fiber 11 is r1, the distance between the second receiving optical fiber 122 and the transmitting optical fiber 11 is r2, and the distance between the third receiving optical fiber 123 and the transmitting optical fiber 11 is r3.

[0044] In this embodiment, by setting up three sets of receiving optical fibers and arranging multiple fiber bundles of each set of receiving optical fibers evenly around the transmitting optical fiber, accurate layered detection of the superficial papillary layer, middle tissue and deep subcutaneous tissue / arteriovenous plexus of the skin is achieved, accurately capturing the differences in blood flow recovery dynamics of each layer of tissue after pressure release.

[0045] Furthermore, in this embodiment, each set of receiving optical fibers 12 includes at least four fiber bundles, and the fiber bundles of adjacent sets of receiving optical fibers are staggered.

[0046] In this embodiment, by interleaving the fiber bundles of two adjacent sets of receiving fibers, signal blind spots between receiving fibers are effectively avoided, ensuring uniform capture of scattered light from all directions of the tissue under test, and greatly improving the integrity and reliability of signal acquisition. At the same time, the interleaved fiber bundle design reduces optical crosstalk between adjacent channels, enhances the separation of blood flow signals at different depths, and makes the measurement of hemodynamic parameters of superficial and deep tissues more accurate.

[0047] Furthermore, in one embodiment, the control and data calculation and storage module 4 is also used to perform weighted fusion of the refill times of each capillary to obtain the average capillary refill time.

[0048] Among them, the distance from the receiving optical fiber 12 to the transmitting optical fiber 11 is inversely proportional to the weight of the corresponding capillary refill time.

[0049] In this embodiment, a comprehensive CRT value is obtained by weighted fusion of capillary refill times at different depths. This not only retains the advantages of DCS technology in being non-invasive and real-time monitoring microcirculation, but also solves the problem of missed diagnosis of deep microcirculation disorders caused by single-depth measurement.

[0050] Preferably, in this embodiment, the weight of the refill time of the kth capillary is... for: k=1,2,3.

[0051] in, Let be the distance between the receiving fiber 12 and the transmitting fiber 11 of the k-th group.

[0052] In this embodiment, since the shallow tissue signal has a higher signal-to-noise ratio, this weighting strategy reasonably distributes the contribution degrees of measurement results at different depths, fully utilizes the reliability of high-precision shallow-layer data, retains the diagnostic information of deep tissues, effectively avoids the defect that traditional single-depth measurement methods may miss the diagnosis of deep microcirculation disorders, and enables the average capillary refill time to more accurately reflect the overall condition of human microcirculation.

[0053] In other embodiments, a micro-spectral sensor (such as an LED light source + a photodiode) can also be integrated on the side of the front end of the probe structure as a skin color detection module to measure the reflectance of the skin at specific wavelengths (such as 568 nm, 660 nm, 785 nm, 880 nm, etc.), calculate the melanin index, and record it as the skin color parameter P.

[0054] The skin color parameter P of the measured part is obtained through the skin color detection module, and based on the above skin color parameter P, a blood flow time series after skin color correction is obtained. The capillary refill time is calculated based on the corrected blood flow time series.

[0055] Optionally, assuming that the value range of the skin color parameter P is 0 to 100, P is divided into three intervals: light color (0 to 30), medium (31 to 70), and dark (71 to 100). For the light color interval, the corresponding skin color coefficient P1 is obtained; for the medium interval, the corresponding skin color coefficient P2 is obtained; for the dark interval, the corresponding skin color coefficient P3 is obtained. Among them, as the skin color deepens, the skin color coefficient becomes larger, that is, the coefficient of the shallow-layer signal decreases and the coefficient of the deep-layer signal increases, thereby compensating for the influence of melanin absorption.

[0056] In this embodiment, the skin color parameter P of the measured part is obtained in real time through the skin color detection module, and then the skin color coefficient Pi is obtained. Subsequently, it can be processed by a data processing unit including an optical signal receiving and calculating module and a control and data calculating and storing module, including: First, the optical intensity time series I k (t) is collected in real time through three channels formed by 3 groups of receiving optical fibers 12 (r1 < r2 < r3), and the blood flow index BFI k (t) of each channel is obtained through autocorrelation analysis.

[0057] Then, according to the above skin color coefficient, the signals of each group of receiving optical fibers are dynamically adjusted to generate blood flow index information after skin color correction; among them, the blood flow index information after skin color correction is: .

[0058] Finally, capillary refill time was calculated based on the aforementioned blood flow index information. Specifically, the blood flow index data collected from the three channels could be used to calculate the capillary refill time at different depths. , and Based on the weights of capillary refill time, the average value of the three channels is calculated as the comprehensive capillary refill time to reflect the patient's pathological state, i.e.: .

[0059] Furthermore, in one embodiment, the probe structure 1 further includes a plurality of light-blocking rings 13.

[0060] The number of light-blocking rings 13 is the same as the number of sets of receiving optical fibers 12. Each light-blocking ring 13 is respectively disposed between the transmitting optical fiber 11 and the innermost receiving optical fiber 12, and between each pair of adjacent sets of receiving optical fibers 12.

[0061] In this embodiment, the above-mentioned multiple sets of receiving optical fibers 12 include three sets of receiving optical fibers. Correspondingly, three light-blocking rings 13 are provided, which are respectively arranged between the transmitting optical fiber 11 and the first receiving optical fiber 121, between the first receiving optical fiber 121 and the second receiving optical fiber 122, and between the second receiving optical fiber 122 and the third receiving optical fiber 123.

[0062] In this embodiment, by adding multiple light-blocking rings equal to the number of receiving fiber groups, an optical isolation barrier is effectively constructed, suppressing optical crosstalk between detection channels at different depths.

[0063] Preferably, in this embodiment, the surface of each of the above-mentioned light-blocking rings 13 is a black matte light-absorbing material.

[0064] In this embodiment, by using a black matte light-absorbing material, optical crosstalk between detection channels at different depths can be significantly suppressed, greatly improving the purity and signal-to-noise ratio of each channel signal.

[0065] Furthermore, in one embodiment, the probe structure 1 is provided with a pressure mechanism.

[0066] The aforementioned control and data calculation and storage module 4 is also used to control the pressure mechanism to apply controllable pressure to the tissue being tested.

[0067] Preferably, the pressure mechanism is a miniature airbag.

[0068] In this embodiment, by integrating a pressure mechanism into the probe structure and linking it with the control and data calculation and storage module, the capillary refill time measurement process is automated and standardized. This eliminates the problem of inconsistent pressure caused by operator differences in the traditional manual pressing method, ensuring that the pressure applied for each measurement is accurate, controllable, and repeatable, and greatly improving the reliability and comparability of the test results.

[0069] Furthermore, the aforementioned device also includes a display and interaction module 5. This display and interaction module is used to display the capillary refill time at various depths, the average capillary refill time, and the blood flow index versus time curve.

[0070] Specifically, the device in this embodiment includes a laser 6, a light source adjustment module 7, a probe structure 1, an optical signal receiving and calculation module 3, a control and data calculation and storage module 4, and a display and interaction module 5. The probe structure 1 is a pressure and optical probe.

[0071] In this embodiment, the laser 6 emits a near-infrared laser light source of a specific wavelength, which is transmitted through an optical fiber after passing through the light source adjustment module 7. The optical fiber is coupled with the pressure and optical probe, so the light can be emitted from the front end of the pressure and optical probe. The front of the pressure and optical probe is in contact with the human tissue being tested, so that the light can irradiate the tissue being tested.

[0072] Because near-infrared light is strongly scattered by moving scatterers when it propagates in biological tissues, pressure and optical probes can receive the scattered light and then transmit it through optical fiber to the optical signal receiving and calculation module. The optical signal receiving and calculation module can monitor and analyze the phase changes of the scattered light in different channels, thereby calculating the autocorrelation function of the scattered light intensity of each channel.

[0073] The aforementioned control and data calculation and storage module can control the inflation and deflation of the micro-inflators of the pressure and optical probes, thereby realizing the compression state of the tissue by the pressure and optical probes and acquiring the pressure values. The control and data calculation and storage module analyzes the autocorrelation function of each channel to calculate the blood flow index (BFI) of the detection area. The blood flow index reflects the blood flow in the tissue. Then, the blood flow index is correlated with time to form a curve of blood flow index versus time. Combined with the pressure data acquired by the pressure sensor, the CRT value corresponding to each channel can be calculated. The control and data calculation and storage module can receive signals transmitted from the display and interaction module to control the operation of the light source adjustment module, pressure and optical probes, etc.

[0074] The aforementioned display and interaction modules are used to display human body parameters such as relative blood flow curves, CRT values, and pressure values.

[0075] like Figure 3The annular probe layout shown has a single-mode optical fiber in the middle as the transmitting optical fiber, which is used to transmit laser light with a preset wavelength. Optionally, the above-mentioned preset wavelength is 400 nm - 1100 nm. In this embodiment, the above-mentioned preset wavelength is 785 nm.

[0076] In other embodiments, the above-mentioned preset wavelength can also be other wavelengths, which are selected according to the actual situation.

[0077] The above-mentioned first receiving optical fiber 121 is composed of 4 optical fiber bundles. These 4 optical fiber bundles are arranged annularly and evenly around the transmitting optical fiber. The center distance between the 4 optical fiber bundles of the first receiving optical fiber and the transmitting optical fiber is r1.

[0078] The above-mentioned second receiving optical fiber 122 is composed of 4 optical fiber bundles. These 4 optical fiber bundles are arranged annularly and evenly around the transmitting optical fiber and are arranged crosswise with the first receiving optical fiber. The center distance between the 4 optical fiber bundles of the second receiving optical fiber and the transmitting optical fiber is r2.

[0079] The above-mentioned third receiving optical fiber 123 is composed of 4 optical fiber bundles. These 4 optical fiber bundles are arranged annularly and evenly around the transmitting optical fiber and are arranged crosswise with the second receiving optical fiber. The center distance between the 4 optical fiber bundles of the third receiving optical fiber and the transmitting optical fiber is r3.

[0080] The intervals between the above-mentioned receiving optical fibers and the transmitting optical fiber satisfy r1 < r2 < r3. The receiving optical fiber with a larger interval distance can detect blood flow signals in deeper layers.

[0081] In other embodiments, the number of optical fiber bundles of the above-mentioned first receiving optical fiber 121, second receiving optical fiber 122, and third receiving optical fiber 123 is also set to more than 4.

[0082] Furthermore, light-blocking spacer rings 13 are designed between the transmitting optical fiber 11 and the first receiving optical fiber 121, between the first receiving optical fiber 121 and the second receiving optical fiber 122, and between the second receiving optical fiber 122 and the third receiving optical fiber 123. The surface of the light-blocking spacer ring 13 is made of a black matte light-absorbing material, which can reduce the influence of different channels on the signal and improve the signal-to-noise ratio of each channel.

[0083] In this embodiment, through the design of a multi-spacing fiber array, a fiber transmitting channel and detection channels with different fiber receptions are integrated in a single probe, so that CRT parameters of multiple layers of tissues can be synchronously obtained in one system.

[0084] The capillary refill detection device of this embodiment can detect CRT values at different depths through the probe structure design and algorithm design, and comprehensively evaluate and calculate the average CRT value according to the CRT values at different depths, so as to measure the microcirculation status of the human body according to the average CRT value.

[0085] Secondly, embodiments of the present invention also provide a detection method based on the above-mentioned capillary refill detection device.

[0086] In one embodiment, the detection method includes: S1. Near-infrared light is emitted to the tissue under test through the transmitting optical fiber 11, and the light signals scattered back from different depths of the tissue under test are simultaneously received through multiple sets of receiving optical fibers 12. S2. The optical signal receiving and calculation module 3 receives the optical signals transmitted by each receiving optical fiber 12 and obtains the autocorrelation function of the intensity of each scattered light; S3. The control and data calculation and storage module 4 calculates the blood flow index of the corresponding depth tissue based on the autocorrelation function of each scattered light intensity, and fits the blood flow index versus time curve to obtain the capillary refill time at each depth.

[0087] Based on the above embodiments, in this embodiment, step S3, which involves obtaining the capillary refill time at each depth, specifically includes: Based on the blood flow index and time curves, the time interval from pressure release to the first recovery of the blood flow index to the level before pressure application at each depth was determined as the capillary refill time at each depth.

[0088] Furthermore, in this embodiment, after obtaining the capillary refill time at each depth in step S3 above, the method further includes: Step S4. Weight and fuse the refill times of each capillary to obtain the average capillary refill time.

[0089] In this embodiment, the weighted fusion of the refill times of each capillary specifically includes: First, the weight of capillary refill time at each depth is determined based on the distance from the receiving fiber 12 to the transmitting fiber 11 in each group; wherein, the distance from the receiving fiber 12 to the transmitting fiber 11 is inversely proportional to the weight of the corresponding capillary refill time.

[0090] Then, based on the weight of the capillary refill time at each depth, the capillary refill time is weighted and fused to obtain the average capillary refill time.

[0091] like Figure 4 As shown, the solid line represents the change in BFI, and the dashed line represents the change in pressure. In this embodiment, the measurement of the CRT value follows the following time series and calculation process: 0-T0: Start acquisition to obtain stable blood flow signals.

[0092] T0: The pressure mechanism begins to apply a certain pressure to the tissue being tested.

[0093] T0-T1: The pressure value quickly reaches a stable level. Due to the compression of tiny blood vessels, the blood flow index in the area decreases.

[0094] T1: The moment to release stress.

[0095] T2: The moment when the blood flow index (BFI) first recovers to the level of 0-T0.

[0096] T1-T2: The time interval from pressure release to the first recovery of the blood flow index (BFI) to the value between 0 and T0. This time interval is clinically equivalent to the CRT value.

[0097] .

[0098] The CRT values ​​measured by the three channels consisting of three sets of receiving optical fibers 12 and transmitting optical fibers 11 are obtained and denoted as CRT1, CRT2 and CRT3, respectively, reflecting the blood return situation after the blood flow at different depths is pressed.

[0099] Secondly, the CRT values ​​calculated at different intervals can be weighted and summed to obtain a comprehensive CRT value for the human body, making the result more clinically representative. The smaller the distance between the receiver and transmitter, the shallower the detection depth, the higher the signal-to-noise ratio, and the greater the weight. The weighting is calculated as follows: k=1,2,3.

[0100] The formula for calculating the average CRT value is as follows: .

[0101] Where k represents different detection channels, w k The weight represents the k-th CRT value.

[0102] like Figure 5 As shown, in this embodiment, taking T0 as 10s and the interval from T0 to T1 as 15s as an example, the detection method based on the above-mentioned capillary refill detection device specifically includes: A1. Fix the probe structure to the tissue being tested; A2. Start the device to acquire blood flow signals; A3. Activate the pressure mechanism and turn to A4 and A13.

[0103] A4. Acquire blood flow signals; A5. Calculate the blood flow index (BFI) value; A6. Generate BFI values ​​and time curves at different depths; A7. Click to start CRT measurement; A8. Calculate the average BFI value over the first 10 seconds; At 10s, the pressure mechanism is triggered and pressure is applied to the tissue under test, then the circuit switches to A10 and A13.

[0104] A10. Press firmly and continuously for 15 seconds; A11. Pressure relief mechanism; A12. Wait 15 seconds, then turn onto A15.

[0105] A13. Obtain the pressure value; A14. Displays the pressure curve; A15. Displays pressure and CRT values ​​at different depths or the average CRT value, such as... Figure 6 As shown.

[0106] In the above-mentioned detection method embodiments, each step corresponds to the function of each module in the above-mentioned detection device embodiments, and their functions and implementation processes will not be described in detail here.

[0107] It should be noted that the sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0108] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0109] In the description of the embodiments of the present invention, terms such as "exemplary," "for example," or "for instance" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary," "for example," or "for instance" in the embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.

[0110] In the description of the embodiments of the present invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" means two or more.

[0111] In some processes described in the embodiments of the present invention, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of the present invention, or may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0112] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of the present invention.

[0113] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A capillary refill detection device based on diffusion correlation spectroscopy, characterized in that, The device includes: The probe structure (1) includes a transmitting optical fiber (11) and multiple sets of receiving optical fibers (12). The transmitting optical fiber (11) is connected to a near-infrared light source and is used to transmit near-infrared light to the tissue under test (2). Each set of receiving optical fibers (12) is at a different distance from the transmitting optical fiber (11) and is used to receive the light signal scattered back from the tissue under test (2). The optical signal receiving and calculation module (3) is used to receive the optical signals transmitted by each receiving optical fiber (12) and obtain the autocorrelation function of the intensity of each scattered light. The control and data calculation and storage module (4) is used to calculate the blood flow index of the tissue at the corresponding depth based on the autocorrelation function of the light intensity of each scattered light, and to fit the blood flow index and time curve to obtain the capillary refill time at each depth.

2. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 1, characterized in that: The multiple sets of receiving optical fibers (12) include three sets of receiving optical fibers, which are respectively at distances r1, r2 and r3 from the transmitting optical fiber (11), wherein r1 <r2<r3; Each receiving fiber (12) includes multiple fiber bundles, and each fiber bundle is arranged uniformly around the transmitting fiber (11).

3. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 2, characterized in that: Each set of receiving optical fibers (12) includes at least four fiber bundles, with the fiber bundles of adjacent sets of receiving optical fibers being staggered.

4. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 1, characterized in that: The control and data calculation and storage module (4) is also used to perform weighted fusion of the refill times of each capillary to obtain the average capillary refill time. Among them, the distance from the receiving optical fiber (12) to the transmitting optical fiber (11) is inversely proportional to the weight of the corresponding capillary refill time.

5. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 4, characterized in that, Weight of the k-th capillary refill time for: ，k=1,2,3； in, The distance between the receiving fiber (12) and the transmitting fiber (11) of the kth group is given.

6. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 1, characterized in that, The probe structure (1) also includes: Multiple light-blocking rings (13) are provided, the number of which is the same as the number of receiving optical fibers (12); each light-blocking ring (13) is respectively disposed between the transmitting optical fiber (11) and the innermost receiving optical fiber (12), and between each two adjacent sets of receiving optical fibers (12).

7. The capillary refill detection device based on diffusion correlation spectroscopy as described in claim 1, characterized in that: The probe structure (1) is equipped with a pressure mechanism; The control and data calculation and storage module (4) is also used to control the pressure mechanism to apply controllable pressure to the tissue under test (2).

8. A detection method based on the diffusion correlation spectroscopy-based capillary refill detection device as described in claim 1, characterized in that, The method includes: Near-infrared light is emitted to the tissue under test (2) through the transmitting optical fiber (11), and the light signals scattered back from different depths of the tissue under test (2) are received synchronously through multiple sets of receiving optical fibers (12). The optical signal receiving and calculation module (3) receives the optical signals transmitted by each receiving fiber (12) and obtains the autocorrelation function of the intensity of each scattered light. The control and data calculation and storage module (4) calculates the blood flow index of the tissue at the corresponding depth based on the autocorrelation function of the light intensity of each scattered light, and fits the blood flow index with the time curve to obtain the capillary refill time at each depth.

9. The detection method of the capillary refill detection device based on diffusion correlation spectroscopy as described in claim 8, characterized in that, This allows us to obtain the capillary refill time at various depths, specifically including: Based on the blood flow index and time curves, the time interval from pressure release to the first recovery of the blood flow index to the level before pressure application at each depth was determined as the capillary refill time at each depth.

10. The detection method of the capillary refill detection device based on diffusion correlation spectroscopy as described in claim 8, characterized in that, After obtaining the capillary refill time at various depths, the following also includes: The weight of capillary refill time at each depth is determined based on the distance from the receiving fiber (12) to the transmitting fiber (11) of each group; the distance from the receiving fiber (12) to the transmitting fiber (11) is inversely proportional to the weight of the corresponding capillary refill time. Based on the weight of capillary refill time at each depth, the refill times of each capillary are weighted and fused to obtain the average capillary refill time.

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