Blood oxygen saturation monitoring method and device of hemodialysis pipeline based on double optical paths
By designing wide and narrow diameter sections in the hemodialysis tubing, and combining the measurement of transmitted light intensity of red and infrared light with data buffer calibration, the problem of accuracy in monitoring blood oxygen saturation during hemodialysis was solved, enabling real-time and accurate monitoring during hemodialysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-10
AI Technical Summary
Traditional non-invasive pulse oximetry monitoring technology cannot be effectively applied during hemodialysis and is easily affected by environmental interference, leading to inaccurate measurement results.
A dual-path hemodialysis tubing design was adopted. By setting wide and narrow diameter sections in the tubing, and combining the transmission light intensity measurements of red and infrared light, a data buffer was constructed and data calibration was performed. The AC and DC components were calculated to determine blood oxygen saturation.
It enables real-time and accurate monitoring of blood oxygen saturation during hemodialysis, reduces environmental noise interference, and improves the stability and accuracy of monitoring.
Smart Images
Figure CN121817878A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of hemodialysis monitoring, and more particularly to a method and device for monitoring blood oxygen saturation of a hemodialysis pipeline based on double light paths. BACKGROUND
[0002] As a core physiological parameter reflecting the oxygen-carrying capacity of human blood, real-time and accurate monitoring of blood oxygen saturation is of great importance to disease diagnosis, condition monitoring and health management, and is a key indicator for evaluating the respiratory and circulatory functions of the body. In particular, in the context of hemodialysis treatment, patients with kidney failure rely on dialysis equipment to maintain metabolic balance in the body, and the hemodynamic state of the body is prone to fluctuation during treatment, which may cause complications such as hypoxia and hypotension, seriously threatening the safety of patients. Therefore, real-time monitoring of blood oxygen saturation throughout the hemodialysis treatment process can provide a reliable basis for medical personnel to adjust treatment plans and take intervention measures, and is a core prerequisite for ensuring the safety and effectiveness of hemodialysis treatment.
[0003] Traditional non-invasive pulse blood oxygen saturation monitoring technology relies on the periodic pulsation of arterial blood vessels. This pulsation causes changes in blood vessel volume, thereby generating an alternating current (AC) component in the photoplethysmogram (PPG) signal, and blood oxygen saturation (SpO2) is calculated by analyzing the ratio of the AC component to the direct current (DC) component.
[0004] However, in the context of extracorporeal circulation such as hemodialysis, blood is smoothly flowing in the pipeline driven by a blood pump, lacking effective physiological pulsation signals, which makes the traditional technology unable to be directly applied. In addition, extracorporeal testing of blood oxygen saturation is also susceptible to interference, affecting the accuracy of the measurement results, such as environmental light interference in a clinical environment, such as indoor light, shadows caused by people walking, and random noise caused by device operation interference and physiological signal fluctuations of the human body. SUMMARY
[0005] The present application aims to overcome at least one of the above-mentioned defects (shortcomings) of the prior art, and provides a method and device for monitoring blood oxygen saturation of a hemodialysis pipeline based on double light paths, for realizing extracorporeal monitoring of blood oxygen saturation and providing reliable monitoring results.
[0006] The present application provides a method for monitoring blood oxygen saturation of a hemodialysis pipeline based on double light paths, The hemodialysis pipeline comprises a narrow diameter section and a wide diameter section connected in series, the pipe diameter of the wide diameter section being greater than the pipe diameter of the narrow diameter section, The blood oxygen saturation monitoring method comprises the following steps: S1, respectively irradiating the narrow diameter section of the hemodialysis pipeline with red light and infrared light, and obtaining the transmitted light intensity I of the red light passing through the narrow diameter section of the hemodialysis pipeline the narrow diameter section1红光 and infrared light intensity I passing through the hemodialysis pipeline 1红外 ; S2, respectively using red light and infrared light to irradiate the wide diameter section of the hemodialysis pipeline, obtaining the transmitted light intensity I of the red light passing through the wide diameter section of the hemodialysis pipeline 2红光 and infrared light intensity I passing through the hemodialysis pipeline 2红外 ; S3, constructing a data buffer, the data buffer storing the latest N light intensity sampling values, wherein N is a positive integer, the data buffer including a first data buffer, a second data buffer, a third data buffer and a fourth data buffer arranged independently, the first data buffer being used to store I 1红光 , and forming a data set buffer 1红光 in a time sequence, the second data buffer being used to store I 1红外 , and forming a data set buffer 1红外 in a time sequence, the third data buffer being used to store I 2红光 , and forming a data set buffer 2红光 in a time sequence, the fourth data buffer being used to store I 2红外 , and forming a data set buffer 2红外 in a time sequence, calculating the arithmetic mean value of the data in the data set, obtaining the representative narrow diameter section red light transmitted light intensity I 1红光avg (t) at time t, the narrow diameter section infrared light transmitted light intensity I 1红外avg (t) ， wide diameter section red light transmitted light intensity I 2红光avg (t) and wide diameter section infrared light transmitted light intensity I 1红外avg (t), t corresponding to the collection time of the Nth sampling point in the data buffer, the calculation formulas being as follows: I 1红光avg (t) = Mean(buffer 1红光 ), I 1红外光avg (t)= Mean(buffer 1红外 ), I 2红光avg (t)= Mean(buffer 2红光 ), I 2红外光avg (t) = Mean(buffer 2红外 )。
[0007] S4, calculating the AC component and the DC component based on I 1红光avg (t), I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t), and calculating the blood oxygen saturation SpO2 based on the AC component and the DC component.
[0008] Further, the step S1 comprises: S11, respectively irradiating the narrow-diameter section of the hemodialysis pipeline with red light and infrared light, collecting the transmitted light intensity I 1红光total (t) of the red light passing through the narrow-diameter section of the hemodialysis pipeline and the transmitted light intensity I 1红外光total (t) of the infrared light passing through the narrow-diameter section of the hemodialysis pipeline at time t, and simultaneously collecting the transmitted light intensity I N1 (t) of the natural ambient light passing through the narrow-diameter section of the hemodialysis pipeline at time t, S12, calculating I 1红光 (t) and I 1红外 (t), according to the following formula: I 1红光 (t) = I 1红光_total (t) - I N1 (t); I 1红外 (t) = I 1红外光total (t) - I N1 (t); Further, the step S2 comprises: S21, respectively irradiating the wide-diameter section of the hemodialysis pipeline with red light and infrared light, collecting the transmitted light intensity I 2红光total (t) of the red light passing through the wide-diameter section of the hemodialysis pipeline and the transmitted light intensity I 2红外光total (t) of the infrared light passing through the wide-diameter section of the hemodialysis pipeline at time t, and simultaneously collecting the transmitted light intensity I N (t) of the natural ambient light passing through the wide-diameter section of the hemodialysis pipeline at time t, S12, calculating I 2红光 (t) and I 2红外 (t), according to the following formula: I 2红光 (t) = I 2红光total (t) - I N2 (t); I 2红外 (t) = I 2红外光total (t) - I N2 (t); Further, before the step S1, the following step is further included: S0, before dialysis starts, fill the hemodialysis pipeline with deionized water, respectively use red light and infrared light to irradiate the narrow diameter section of the hemodialysis pipeline, collect the transmission light intensity I 1红光water and infrared light through the narrow diameter section of the hemodialysis pipeline 1红外光water ; respectively use red light and infrared light to irradiate the wide diameter section of the hemodialysis pipeline, collect the transmission light intensity I 2红光water and infrared light through the narrow diameter section of the hemodialysis pipeline 2红外光water ; Step S4 comprises: S41, based on I 1红光water , I 1红外光water , I 2红光water , I 2红外光water , I 1红光avg (t), I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t), normalize calibration to obtain I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t); S42, based on I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t), calculate AC component and DC component; S43, based on the AC component and the DC component, calculate the blood oxygen saturation SpO2.
[0009] Specifically, the calculation formulas of I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t) are as follows: I 1红光final (t)= I 1红光avg (t)- I 1红光water ; I 1红外光final (t)= I 1红外光avg (t)- I 1红光water ; I 2红光final (t)= I 2红光avg (t)- I 2红光water ; I 2红外光final (t)= I 2红外光avg (t)- I 2红外光water .
[0010] Further, the step S42 is specifically: the AC component includes the AC component of red light ΔI 红光 and the AC component of infrared light ΔI 红外光 The DC component includes the DC component of red light DC 红光 and the DC component of infrared light DC 红外光 The calculation formula is as follows: ; ; ; .
[0011] Further, the step S43 includes the following steps: S431, calculate the dual-wavelength modulation ratio R, and the calculation formula is as follows: ; S432, calculate the blood oxygen saturation SpO2, and the calculation formula is as follows: SpO2=a×R+b, Wherein, a and b are pre-calibration coefficients.
[0012] Another object of the present application is to provide a dual optical path based hemodialysis pipeline blood oxygen saturation monitoring device, suitable for any one of the above-mentioned blood oxygen saturation monitoring method, the blood oxygen saturation monitoring device includes a hemodialysis pipeline, the hemodialysis pipeline includes a wide diameter section and a narrow diameter section connected, the wide diameter section and the narrow diameter section are provided with a light source device on one side, the light source device is used to emit light to irradiate the hemodialysis pipeline; The other side of the wide diameter section is provided with a light detection device for detecting the transmission light through the hemodialysis pipeline.
[0013] Further, the light source device includes a first light source device and a second light source device, the first light source device is used to irradiate the narrow diameter section, the second light source device is used to irradiate the wide diameter section, the light detection device includes a first sensor, a second sensor and a third sensor and a fourth sensor, the first sensor is used to detect the transmission light of the first light source device in the narrow diameter section, the second sensor is used to detect the transmission light of the second light source device in the wide diameter section, the third sensor is used to detect the transmission light of the natural environment light in the narrow diameter section, and the fourth sensor is used to detect the transmission light of the natural environment light in the wide diameter section.
[0014] Further, the first sensor collects data, and the second sensor collects data after a delay time T, the distance between the first sensor and the second sensor is L, the blood flow rate in the hemodialysis pipeline is V, and the calculation formula of the delay time T is: T=L / V.
[0015] Further, a controller is further included, which is connected with the light source device and the light detection device.
[0016] Compared with the prior art, the present application has the following advantages: (1) A wide diameter section and a narrow diameter section with a fixed inner diameter difference are designed on the extracorporeal circulation pipeline, the spatial optical path difference is converted into the light intensity fluctuation signal in time sequence received by the sensor through the continuous flow of blood, thereby simulating the dynamic signal required by the traditional pulse oximeter, and real-time monitoring of the blood oxygen saturation on the extracorporeal hemodialysis pipeline is realized.
[0017] (2) Through the construction of the data buffer area, random noise is inhibited, the anti-interference ability is improved, and the stability and accuracy of the blood oxygen saturation monitoring data are improved.
[0018] (3) By eliminating the environmental light component from the original data, the pure effective optical signal is extracted, the influence of the environmental light on the detection result is avoided, and the accuracy of the monitoring result is improved.
[0019] (4) Through the optical channel consistency calibration, the inherent differences such as the intensity of the LED light source, the sensitivity of the sensor, and the light transmittance of the pipe wall are eliminated, and the interference factors of the monitoring result are further reduced. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a structural schematic view of the oxygen saturation monitoring device of the present application.
[0021] The figure mark: hemodialysis pipeline 100, wide diameter section 110, narrow diameter section 120, first light source device 210, second light source device 220, first sensor 310, second sensor 320, third sensor 330, fourth sensor 340. DETAILED DESCRIPTION
[0022] The drawings of the present application are only used for illustrative description, and cannot be understood as the limitation of the present application. In order to better illustrate the following embodiments, some components of the drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some known structures and their descriptions in the drawings can be omitted.
[0023] Embodiment 1 The present embodiment provides a hemodialysis pipeline blood oxygen saturation monitoring method based on double optical paths, The hemodialysis pipeline comprises a narrow diameter section and a wide diameter section connected in series, the pipe diameter of the wide diameter section is greater than the pipe diameter of the narrow diameter section, The blood oxygen saturation monitoring method comprises the following steps: S1, respectively using red light and infrared light to irradiate the narrow diameter section of the hemodialysis pipeline, and acquiring the transmission light intensity I of the red light passing through the narrow diameter section of the hemodialysis pipeline The narrow diameter section of the hemodialysis pipeline1红光 and infrared light intensity I passing through the blood dialysis pipeline 1红外 ; S2, respectively, using red light and infrared light irradiation blood dialysis pipeline wide diameter section, to obtain red light passing through the blood dialysis pipeline wide diameter section transmission light intensity I 2红光 and infrared light intensity I passing through the blood dialysis pipeline 2红外 ; S3, construct a data buffer, the data buffer stores the latest N light intensity sampling value, wherein N is a positive integer, the data buffer includes a first data buffer, a second data buffer, a third data buffer and a fourth data buffer, the first data buffer is used for storing I 1红光 , and forms a data set buffer 1红光 in time series, the second data buffer is used for storing I 1红外 , and forms a data set buffer 1红外 in time series, the third data buffer is used for storing I 2红光 , and forms a data set buffer 2红光 in time series, the fourth data buffer is used for storing I 2红外 , and forms a data set buffer 2红外 in time series, the arithmetic mean value of the data in the data set is calculated, and the representative narrow diameter section red light transmission light intensity I 1红光avg (t) and narrow diameter section infrared light transmission light intensity I 1红外avg (t) ， wide diameter section red light transmission light intensity I 2红光avg (t) and wide diameter section red light transmission light intensity I 1红外avg (t), t corresponds to the collection time of the Nth sampling point in the data buffer, and the calculation formula is as follows: I 1红光avg (t) = Mean(buffer 1红光 ), I 1红外光avg (t)= Mean(buffer 1红外 ), I 2红光avg (t)= Mean(buffer 2红光 ), I 2红外光avg (t) = Mean(buffer 2红外 )。
[0024] S4, based on I 1红光avg (t), I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t) Calculate the AC and DC components, and calculate the blood oxygen saturation SpO2 based on the AC and DC components.
[0025] In this solution, "wide" and "narrow" are relative terms; the diameter of the narrow section is smaller than that of the wide section. The hemodialysis tubing is connected to the dialysis tubing (or a dedicated tubing is used), through which blood flows. This solution constructs a static optical path difference using the wide and narrow sections of the hemodialysis tubing. Through dual-channel differential measurement and blood flow timing analysis, a "quasi-dynamic" optical signal is reconstructed in a pulsatile environment, enabling non-invasive real-time monitoring of blood oxygen saturation. Furthermore, this solution suppresses random noise and improves anti-interference capabilities by constructing a data buffer, thereby enhancing the stability and accuracy of blood oxygen saturation monitoring data and providing reliable blood oxygen saturation monitoring results for medical personnel.
[0026] Specifically, N can preferably be 2 to 20, for example, 3, 6, or 10. The Mean (buffer) 1红光 To obtain the buffer 1红光 Mean(buffer) is the average value of the data. 1红外 Mean(buffer) 2红光 ) and Mean(buffer 2红外 Similarly, the data buffer stores light intensity samples within a time window [tN, t], where, for example, n is the index of the sampling point number, and I... 1红光tn For the light intensity value of the narrow segment collected at the nth sampling time tn, the first data buffer stores the most recent 8 light intensity sample values. 1红光 ={I 1红光t1， I 1红光t2， I 1红光t3， I 1红光t4， I 1红光t5， I 1红光t6， I 1红光t7， I 1红光t8}, I 1红光avg (t) represents the dataset buffer at time t8. 1红光 The average value of all light intensity values within the range.
[0027] Further, step S1 includes: S11. Irradiate the narrow section of the hemodialysis tubing with red light and infrared light respectively, and collect the intensity I of the transmitted light from the red light through the narrow section of the hemodialysis tubing at time t. 1红光total (t) and the intensity of the transmitted light I through the hemodialysis tubing.1红外光total (t), while collecting the transmission light intensity I N1 (t), S12, calculating I 1红光 (t) and I 1红外 (t), and the formula is as follows: I 1红光 (t) = I 1红光_total (t) - I N1 (t); I 1红外 (t) = I 1红外光total (t) - I N1 (t); Further, step S2 comprises: S21, respectively irradiating the wide diameter section of the hemodialysis pipeline with red light and infrared light, collecting the transmission light intensity I 2红光total (t) and the transmission light intensity I 2红外光total (t) of infrared light passing through the wide diameter section of the hemodialysis pipeline, while collecting the transmission light intensity I N2 (t) of natural environment light passing through the wide diameter section of the hemodialysis pipeline at t moment; S12, calculating I 2红光 (t) and I 2红外 (t), and the formula is as follows: I 2红光 (t) = I 2红光total (t) - I N2 (t); I 2红外 (t) = I 2红外光total (t) - I N2 (t); In the technical solution, the environmental light component is removed from the original data, the pure effective optical signal is extracted, the influence of the environmental light on the detection result is avoided, and the accuracy of the monitoring result is improved.
[0028] Further, before step S1, the following steps are further included: S0, before dialysis starts, filling the hemodialysis pipeline with deionized water, respectively irradiating the narrow diameter section of the hemodialysis pipeline with red light and infrared light, collecting the transmission light intensity I 1红光water and the transmission light intensity I 1红外光water of infrared light passing through the narrow diameter section of the hemodialysis pipeline; respectively irradiating the wide diameter section of the hemodialysis pipeline with red light and infrared light, collecting the transmission light intensity I 2红光water and the transmission light intensity I 2红外光water of infrared light passing through the narrow diameter section of the hemodialysis pipeline; Step S4 comprises: S41, based on I 1红光water , 1红外光water , 2红光water , 2红外光water , I 1红光avg (t) is normalized and calibrated to obtain I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t) are normalized and calibrated to obtain I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t); S42, based on I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t) to calculate AC component and DC component; S43, based on AC component and DC component to calculate blood oxygen saturation SpO2.
[0029] Specifically, the calculation formula of I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t) is as follows: I 1红光final (t) = I 1红光avg (t) - I 1红光water ; I 1红外光final (t) = I 1红外光avg (t) - I 1红光water ; I 2红光final (t) = I 2红光avg (t) - I 2红光water ; I 2红外光final (t) = I 2红外光avg (t) - I 2红外光water .
[0030] In the technical solution, the optical channel consistency calibration is used to eliminate inherent differences such as LED light source intensity, sensor sensitivity and pipe wall light transmittance, and further reduce interference factors of the monitoring result.
[0031] Further, step S42 specifically comprises: the AC component includes the AC component ΔI 红光 of red light and the AC component ΔI 红外光 of infrared light, the DC component includes the DC component DC 红光 of red light and the DC component DC 红外光 of infrared light, and the calculation formula is as follows: ; ; ; .
[0032] Further, the step S43 comprises the following steps: S431, calculating the dual-wavelength modulation ratio R, the calculation formula is as follows: ; S432, calculating the blood oxygen saturation SpO2, the calculation formula is as follows: SpO2= a × R + b, Wherein, a and b are pre-calibration coefficients.
[0033] Embodiment 2 As Figure 1 shown, the present embodiment provides a dual-optical-path-based blood oxygen saturation monitoring device for hemodialysis pipeline 100, which is suitable for the blood oxygen saturation monitoring method provided in Embodiment 1. The blood oxygen saturation monitoring device includes a hemodialysis pipeline 100, which includes a wide diameter section 110 and a narrow diameter section 120 connected together. A light source device is arranged on one side of the wide diameter section 110 and the narrow diameter section 120, and is used to emit light to irradiate the hemodialysis pipeline 100. A light detection device is arranged on the other side of the wide diameter section 110, and is used to detect the transmitted light passing through the hemodialysis pipeline 100.
[0034] Further, the light source device includes a first light source device 210 and a second light source device 220. The first light source device 210 is used to irradiate the narrow diameter section 120, and the second light source device 220 is used to irradiate the wide diameter section 110. The light detection device includes a first sensor 310, a second sensor 320, a third sensor 330, and a fourth sensor 340. The first sensor 310 is used to detect the transmitted light of the first light source device 210 on the narrow diameter section 120. The second sensor 320 is used to detect the transmitted light of the second light source device 220 on the wide diameter section 110. The third sensor 330 is used to detect the transmitted light of the natural environment light on the narrow diameter section 120. The fourth sensor 340 is used to detect the transmitted light of the natural environment light on the wide diameter section 110.
[0035] The first light source device 210 and the second light source device 220 are both arranged to emit red light and infrared light. For example, the red light has a wavelength of 630 nm, and the infrared light has a wavelength of 930 nm. The arrangement of the four sensors realizes the simultaneous collection of the transmitted light data of the environment light and the red light / infrared light, and realizes the real-time avoidance of the influence of the environment light on the accuracy of the monitoring data.
[0036] In the technical solution, a wide diameter section 110 with a fixed inner diameter difference and a narrow diameter section 120 are designed on the extracorporeal circulation pipeline, the optical path difference in space is converted into the light intensity fluctuation signal in time sequence received by the sensor through the continuous flow of blood, so that the dynamic signal required by the traditional pulse blood oxygen instrument is simulated, and the real-time monitoring of the blood oxygen saturation on the extracorporeal hemodialysis pipeline 100 is realized.
[0037] Preferably, the first light source device 210, the second light source device 220, the first sensor 310, the second sensor 320, the third sensor 330 and the fourth sensor 340 of the embodiment can be arranged in the housing respectively, and the pipe wall of the hemodialysis pipeline 100 seals the opening of the housing.
[0038] Further, the first sensor 310 collects data, and the second sensor 320 collects data after a delay time T, the distance between the first sensor 310 and the second sensor 320 is L, the blood flow rate in the hemodialysis pipeline 100 is V, and the calculation formula of the delay time T is: T=L / V.
[0039] Further, the controller is further connected with the light source device and the light detection device.
[0040] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the technical solutions of the present application, and are not intended to limit the specific embodiments of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the claims of the present application should be included in the protection scope of the claims of the present application.
Claims
1. A method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing, characterized in that, The hemodialysis tubing includes a connected narrow-diameter section and a wide-diameter section, wherein the diameter of the wide-diameter section is larger than the diameter of the narrow-diameter section. The blood oxygen saturation monitoring method includes the following steps: S1. Irradiate the narrow section of the hemodialysis tubing with red light and infrared light respectively, and obtain the red light passing through the hemodialysis tubing. Intensity I of transmitted light in the narrow diameter segment 1红光 Intensity I of transmitted light through the hemodialysis tubing and infrared light 1红外 ; S2. Irradiate the wide section of the hemodialysis tubing with red light and infrared light respectively, and obtain the data of red light passing through the wide section of the hemodialysis tubing. The intensity of transmitted light I 2红光 Intensity I of transmitted light through the hemodialysis tubing and infrared light 2红外 ; S3. Construct a data buffer, which stores the most recent N light intensity sample values, where N is a positive integer. The data buffer includes four independently configured data buffers: a first data buffer, a second data buffer, a third data buffer, and a fourth data buffer. The first data buffer is used to store I 1红光 And form a dataset buffer in the form of a time series. 1红光 , The second data buffer is used to store I 1红外 And form a dataset buffer in the form of a time series. 1红外 , The third data buffer is used to store I 2红光 And form a dataset buffer in the form of a time series. 2红光 , The fourth data buffer is used to store I. 2红外 And form a dataset buffer in the form of a time series. 2红外 , Calculate the arithmetic mean of the data within the dataset to obtain the representative narrow-path red light transmission intensity I at time t. 1红光avg (t), Infrared light transmission intensity I in the narrow diameter section 1红外avg (t) ， Wide-aperture red light transmission intensity I 2红光avg (t) and the red light transmission intensity in the wide-axis segment I 1红外avg (t), where t corresponds to the acquisition time of the Nth sampling point in the data buffer, and the calculation formulas are as follows: I 1红光avg (t) = Mean(buffer 1红光 ), I 1红外光avg (t)= Mean(buffer 1红外 ), I 2红光avg (t)= Mean(buffer 2红光 ), I 2红外光avg (t) = Mean(buffer 2红外 ); S4, based on I 1红光avg (t), I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t) Calculate the AC and DC components, and calculate the blood oxygen saturation SpO2 based on the AC and DC components.
2. The method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing according to claim 1, characterized in that, Step S1 includes: S11. Irradiate the narrow section of the hemodialysis tubing with red light and infrared light respectively, and collect the intensity I of the transmitted light from the red light through the narrow section of the hemodialysis tubing at time t. 1红光total (t) and the intensity of the transmitted light I through the hemodialysis tubing. 1红外光total (t), and simultaneously collect the intensity I of the transmitted light from the ambient light passing through the narrow section of the hemodialysis tubing at time t. N1 (t), S12, Calculate and obtain I 1红光 (t) and I 1红外 (t), the formula is as follows: I 1红光 (t)= I 1红光_total (t)- I N1 (t); I 1红外 (t)= I 1红外光total (t)-I N1 (t)。 3. The method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing according to claim 1, characterized in that, Step S2 includes: S21. Irradiate the wide section of the hemodialysis tubing with red light and infrared light respectively, and collect the intensity I of the transmitted light from the red light through the wide section of the hemodialysis tubing at time t. 2红光total (t) and the intensity of the transmitted light I through the hemodialysis tubing. 2红外光total (t), and simultaneously collect the intensity I of the transmitted light from the ambient light passing through the wide section of the hemodialysis tubing at time t. N2 (t), S12, Calculate and obtain I 2红光 (t) and I 2红外 (t), the formula is as follows: I 2红光 (t)= I 2红光total (t)- I N2 (t); I 2红外 (t)= I 2红外光total (t)-I N2 (t)。 4. The method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing according to claim 1, characterized in that, Before step S1, the following steps are also included: S0. Before dialysis begins, the hemodialysis tubing is filled with deionized water. The narrow section of the tubing is then illuminated with red light and infrared light, respectively. The transmitted light intensity I of the red light passing through the narrow section of the tubing is recorded. 1红光water Intensity I of infrared light transmitted through the narrow section of the hemodialysis tubing 1红外光water The wide section of the hemodialysis tubing was irradiated with red light and infrared light respectively, and the transmitted light intensity I of the red light passing through the wide section of the hemodialysis tubing was collected. 2红光water Intensity I of infrared light transmitted through the narrow section of the hemodialysis tubing 2红外光water ; Step S4 includes: S41, based on I 1红光water I 1红外光water I 2红光water I 2红外光water , will I 1红光avg (t), I 1红外光avg (t), I 2红光avg (t) and I 2红外光avg (t) is normalized and calibrated to obtain I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t); S42, based on I 1红光final (t), I 1红外光final (t), I 2红光final (t) and I 2红外光final (t) Calculate the AC and DC components; S43. Calculate blood oxygen saturation SpO2 based on AC and DC components.
5. The method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing according to claim 4, characterized in that, Step S42 specifically involves: the AC component including the red light AC component ΔI. 红光 and the AC component ΔI of infrared light 红外光 The DC component includes the red light DC component. 红光 DC component of infrared light 红外光 The calculation formula is as follows: ； ； ； 。 6. The method for monitoring blood oxygen saturation based on a dual-optical-path hemodialysis tubing according to claim 5, characterized in that, Step S43 includes the following steps: S431, Based on ΔI 红外光 DC 红外光 ΔI 红光 and DC 红光 Calculate the dual-wavelength modulation ratio R; S432. Calculate blood oxygen saturation SpO2 based on the dual-wavelength modulation ratio R.
7. A blood oxygen saturation monitoring device based on a dual-optical-path hemodialysis tubing, characterized in that, The method for monitoring blood oxygen saturation according to any one of claims 1 to 6 is applicable. The blood oxygen saturation monitoring device includes a hemodialysis tubing, which includes a wide-diameter section and a narrow-diameter section connected together. A light source device is provided on one side of both the wide-diameter section and the narrow-diameter section. The light source device is used to emit light to illuminate the hemodialysis tubing. A light detection device is provided on the other side of the wide-diameter section to detect the transmitted light passing through the hemodialysis tubing.
8. The blood oxygen saturation monitoring device based on a dual-optical-path hemodialysis tubing according to claim 7, characterized in that, The light source device includes a first light source device and a second light source device. The first light source device is used to illuminate a narrow diameter segment, and the second light source device is used to illuminate a wide diameter segment. The light detection device includes a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor is used to detect the transmitted light of the first light source device in the narrow diameter segment, the second sensor is used to detect the transmitted light of the second light source device in the wide diameter segment, the third sensor is used to detect the transmitted light of ambient light in the narrow diameter segment, and the fourth sensor is used to detect the transmitted light of ambient light in the wide diameter segment.
9. The blood oxygen saturation monitoring device based on a dual-optical-path hemodialysis tubing according to claim 8, characterized in that, The first sensor collects data, and after a delay time T, the second sensor is triggered to collect data. Let the distance between the first and second sensors be L, and the blood flow velocity within the hemodialysis tubing be V. The formula for calculating the delay time T is: T = L / V.
10. The blood oxygen saturation monitoring device based on a dual-optical-path hemodialysis tubing according to any one of claims 7 to 9, characterized in that, It also includes a controller, which is connected to the light source device and the light detection device.