Dialysis urea clearance rate on-line monitoring method, computer system and monitoring system

Abstract

The invention relates to the technical field of medical instruments, and provides a dialysis urea clearance rate online monitoring method, a computer system and a monitoring system.The monitoring method comprises the steps that S1, a detection light source is adopted to irradiate dialysis waste liquid, and the incident light intensity I0 is recorded; s2, collecting the initial transmission light intensity I1 penetrating through the dialysis waste liquid and the transmission light intensity It at the current t moment, and calculating the ratio Rt of the urea nitrogen concentration after dialysis to the urea nitrogen concentration before dialysis on the basis of I1 and It; and S3, calculating a urea clearance index Kt / Vt value at the current t moment based on the Rt. The method has the advantages that the final urea clearance index Kt / Vt value is obtained according to the data of the illumination intensity of the dialysis waste liquid, real-time monitoring of urea data is achieved, the accuracy of the final urea clearance rate calculation result is improved, medical staff can conveniently and timely obtain the urea clearance condition of a dialyzer on blood, and the medical staff can conveniently and rapidly know the urea clearance condition of the dialyzer on the blood. In addition, invasive operation in a traditional blood sampling measurement mode is avoided, discomfort brought to a patient is avoided, and the infection risk is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a method, computer system, and monitoring system for online monitoring of dialysis urea clearance rate. Background Technology

[0002] Urea clearance rate is a core indicator for assessing the adequacy of hemodialysis. As a major end product of protein metabolism, the clearance level of urea in the blood effectively reflects the efficiency of dialysis treatment in removing small molecule toxins. Maintaining an adequate urea clearance rate is crucial for controlling uremia symptoms, improving nutritional status, and enhancing long-term survival rates. It is key to ensuring dialysis quality and reducing the risk of complications and death.

[0003] Urea clearance is typically assessed using the urea clearance index (Kt / V). Calculating the Kt / V value requires the urea nitrogen concentration in the patient's blood before and after dialysis. Therefore, blood samples must be drawn from the patient before and after dialysis to measure urea nitrogen concentration. This invasive procedure involves repeated punctures, causing pain to the patient, increasing the risk of infection, and raising the probability of bloodborne disease transmission. Secondly, this method has a time delay; blood samples need to be sent to a laboratory for analysis, failing to reflect the dynamic changes during dialysis in real time, resulting in delayed results. Furthermore, to calculate urea clearance (e.g., Kt / V), blood needs to be drawn before and after dialysis. However, post-dialysis blood draws are susceptible to interference from recirculation and urea rebound, potentially reducing the accuracy of the results and affecting the accurate assessment of dialysis adequacy. Finally, frequent blood draws also increase the workload of medical staff and medical costs. Therefore, researching a method for real-time monitoring of urea data during dialysis is of significant practical importance. Summary of the Invention

[0004] The present invention aims to overcome at least one defect (deficiency) of the prior art and provides an online monitoring method, computer system and monitoring system for dialysis urea clearance rate, which is used to monitor the urea clearance rate in real time during dialysis, so as to facilitate medical staff to obtain urea clearance data in a timely manner.

[0005] One object of the present invention is to provide an online monitoring method for dialysis urea clearance rate, comprising the following steps: S1. Irradiate the dialysis waste liquid with a detection light source and record the incident light intensity I0; S2. Collect the initial transmitted light intensity I1 through the dialysis waste liquid, and the transmitted light intensity at the current time t. I t Based on I1 and I t Calculate the ratio R of post-dialysis urea nitrogen concentration to pre-dialysis urea nitrogen concentration. t ; S3, based on R tCalculate the urea clearance index Kt / V at time t. t value.

[0006] In this technical solution, dialysis waste liquid refers to the waste liquid flowing out of the dialyzer after dialysis has been completed using dialysate; the monitoring light source emits incident light to irradiate the dialysis waste liquid; the initial transmitted light intensity I1 can be understood as the value shortly after the start of dialysis, preferably the transmitted light intensity I1 within 10 minutes of the start of dialysis; the I... t This represents the transmitted light intensity at time t, i.e., the intensity value after dialysis duration t. The urea clearance index Kt / V... t In the values, K is the urea clearance rate of the dialyzer, T is the dialysis time, and V is the urea distribution volume.

[0007] The final urea removal index Kt / V was obtained by analyzing the light intensity data of the dialysis waste liquid. t This method not only enables real-time monitoring of urea data, improving the accuracy of the final urea clearance rate calculation and allowing medical staff to promptly obtain information on the urea clearance status of the blood by the dialyzer, but also avoids invasive procedures in traditional blood collection and measurement methods, preventing unsuitable procedures for patients and reducing the risk of infection.

[0008] Furthermore, when the dialysate flow rate, blood flow rate, or ultrafiltration volume changes, the ratio of the current pre-dialysis urea nitrogen concentration to the pre-dialysis urea nitrogen concentration is calculated and recorded, denoted as R1. The initial transmitted light intensity I1 is then recalibrated using the following formula:

[0009] Further, in step S2, the ratio R of the post-dialysis urea nitrogen concentration to the pre-dialysis urea nitrogen concentration... t The calculation formula is as follows: .

[0010] Furthermore, in step S3, the urea clearance index Kt / V at time t is... t The formula for calculating the value is as follows: , Where UF is the ultrafiltration volume and W is the body weight after ultrafiltration.

[0011] Another object of the present invention is to provide a computer system that runs a program employing any of the above-described evaluation methods, wherein the computer system is provided with a parameter input interface and a result output interface.

[0012] Another object of the present invention is to provide an online monitoring system for dialysis urea clearance rate, applicable to any of the above-mentioned online monitoring methods, including a dialyzer having an inlet and a return outlet, the inlet being connected to an inlet pipeline, the return outlet being connected to a return pipeline, a urea detection device being connected to the return pipeline, and an ultrafiltration branch being provided on the side of the return pipeline away from the urea detection device, and an ultrafiltration pump being provided on the ultrafiltration branch.

[0013] Furthermore, a bypass line is connected between the inlet line and the return line, and the urea detector is located on the side away from the dialyzer at the connection between the bypass line and the return line.

[0014] Furthermore, a bypass valve is provided on the bypass pipeline, and an inlet valve is provided on the inlet pipeline, with the inlet valve located on the side of the bypass pipeline near the dialyzer; a return valve is provided on the return pipeline, with the return valve located on the side of the bypass pipeline near the dialyzer.

[0015] Furthermore, the urea detection device includes a light source emitting module, a light detection module, and a test liquid storage tube. The light source emitting module is used to generate incident light into the test liquid storage tube, and the light detection module is used to receive and detect the transmitted light passing through the test liquid storage tube and output the intensity of the transmitted light. The test liquid storage tube is connected to the return liquid pipeline.

[0016] Furthermore, the detection light source is ultraviolet light, and the wavelength of the ultraviolet light is 270nm~300nm.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The final urea removal index Kt / V was obtained by analyzing the light intensity data of the dialysis waste liquid. t This method not only enables real-time monitoring of urea data, improving the accuracy of the final urea clearance rate calculation and allowing medical staff to promptly obtain information on the urea clearance status of the blood by the dialyzer, but also avoids invasive procedures in traditional blood collection and measurement methods, preventing unsuitable procedures for patients and reducing the risk of infection.

[0018] (2) When the flow rate of dialysate, blood flow rate or ultrafiltration volume changes, the accuracy of urea clearance data is further improved by recalibrating I1 to avoid the influence of factors such as flow rate on the final test results. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the detection system of the present invention.

[0020] Figure 2 This is a schematic diagram of the urea detection device of the present invention.

[0021] Reference numerals: dialyzer 100, inlet line 110, inlet valve 111, return line 120, return valve 121, bypass line 130, bypass valve 131, urea detection device 200, light source emission module 210, emission housing 211, light detection module 220, detection housing 221, test solution storage tube 230, ultrafiltration branch 300, ultrafiltration pump 310, flow control device 400, blood pump 500. Detailed Implementation

[0022] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0023] Example 1 This embodiment provides an online monitoring method for dialysis urea clearance rate, including the following steps: S1. Irradiate the dialysis waste liquid with a detection light source and record the incident light intensity I0; S2. Collect the initial transmitted light intensity I1 through the dialysis waste liquid, and the transmitted light intensity at the current time t. I t Based on I1 and I t Calculate the ratio R of blood urea nitrogen concentration before dialysis to blood urea nitrogen concentration after dialysis. t ; S3, based on R t Calculate the urea clearance index Kt / V at time t. t value.

[0024] Further, in step S2, the ratio R of the pre-dialysis urea nitrogen concentration to the post-dialysis urea nitrogen concentration... t The calculation formula is as follows: .

[0025] In this technical solution, according to Beer-Lanberg's law, with absorbance A, then... ; Where ε is the molar absorptivity, a characteristic constant of a substance's ability to absorb light of a specific wavelength; l is the thickness of the path light takes through the solution; and c is the concentration of the light-absorbing substance.

[0026] At the same time, A = lg (I0 / I) a ), where I0 is the incident light intensity, I a The intensity of transmitted light.

[0027] Therefore, the concentration of the light-absorbing substance can be obtained. ; Real-time concentration of light-absorbing substances in dialysis waste liquid Among them, I t The intensity of transmitted light after dialysis duration t is given.

[0028] Based on this, let the concentration of urea nitrogen before dialysis be c1, then we have: ; Among them, I1 represents the intensity of transmitted light detected in dialysis waste fluid when the urea concentration in the blood is stable shortly after treatment. Let c be the real-time urea nitrogen concentration of the dialysis waste liquid during the dialysis process. t Then we have: ; Among them, I t This represents the real-time transmitted light intensity detected in dialysis waste fluid as the urea concentration in the blood changes slowly during treatment. All values ​​are independent of ε and l, and ε and l do not require calibration.

[0029] Since the concentration of urea nitrogen in dialysis waste fluid is directly proportional to the concentration of urea nitrogen in blood, the ratio of the concentration of urea nitrogen in dialysis waste fluid after dialysis to that before dialysis is equal to the ratio of the concentration of urea nitrogen in blood after dialysis to that before dialysis. Therefore: ; Furthermore, in step S3, the urea clearance index Kt / V at time t is... t The formula for calculating the value is as follows: ; Where t is the dialysis time, UF is the ultrafiltration volume, and W is the post-ultrafiltration weight. Specifically, the dialysis time t and ultrafiltration volume UF can be recorded in real time by the dialysis machine, and the post-dialysis weight W can be obtained by subtracting the ultrafiltration volume from the pre-dialysis weight.

[0030] As another preferred option, if the urea clearance rate is URR, then: ; Furthermore, when the dialysis machine needs to be configured to change the flow rate of the dialysate, the blood pump flow rate, or the ultrafiltration rate during treatment, the blood urea nitrogen concentration remains constant. However, due to the change in the diffusion and convection flow rates of blood and dialysate within the dialyzer, the urea nitrogen concentration in the dialysis waste fluid changes, leading to a change in the absorbance of the dialysis waste fluid. At this point, the transmitted light intensity is re-detected for localization. t Compared to before the flow change t The differences are significant and affect the calculation results of urea clearance rate.

[0031] In this embodiment, when the dialysis machine flow rate changes, the value of R at that time is recorded and saved as R1. When the transmitted light intensity after the flow rate change is detected again, the transmitted light intensity I1 corresponding to the initial concentration at the current flow rate is recalibrated using the value saved in R1.

[0032] Example 2 This embodiment provides a computing system that runs a program using the online monitoring method provided in Embodiment 1. The computer system is equipped with a parameter input interface and a result output interface.

[0033] Example 3 Combination Figure 1 and Figure 2 This embodiment provides a urea detection system for hemodialysis, applicable to the online monitoring method provided in Embodiment 1. The system includes a dialyzer 100, which has an inlet and a return outlet. The inlet is connected to an inlet pipe 110, and the return outlet is connected to a return pipe 120. A urea detection device 200 is connected to the return pipe 120, and an ultrafiltration branch 300 is provided on the side of the return pipe 120 away from the dialyzer 100 from the urea detection device 200.

[0034] In this technical solution, the dialysate enters the dialyzer 100 through the inlet pipe 110 for use, and the used dialysate flows out through the return pipe 120. The urea detection device 200 is used to detect the urea concentration in the dialysate in the return pipe 120. By calculating the urea concentration data in the dialysate, the urea concentration data in the blood can be obtained. This not only enables real-time monitoring of urea data and improves the accuracy of the final urea clearance rate calculation, but also avoids the invasive procedures of traditional blood collection and measurement methods, avoiding unsuitable conditions for patients and reducing the risk of infection.

[0035] Furthermore, a bypass line 130 is connected between the inlet line 110 and the return line 120, and the urea detector is located on the side away from the dialyzer 100 at the connection between the bypass line 130 and the return line 120.

[0036] Furthermore, a bypass valve 131 is provided on the bypass line 130, and an inlet valve 111 is provided on the inlet line 110. The inlet valve 111 is located on the side of the bypass line 130 near the dialyzer 100. A return valve 121 is provided on the return line 120. The return valve 121 is located on the side of the bypass line 130 near the dialyzer 100.

[0037] Furthermore, the urea detection device 200 includes a light source emitting module 210, a light detection module 220, and a test liquid storage tube 230. The light source emitting module 210 is used to generate incident light into the test liquid storage tube 230, and the light detection module 220 is used to receive and detect the transmitted light passing through the test liquid storage tube 230 and output the intensity of the transmitted light. The test liquid storage tube 230 is connected to the return liquid pipeline 120.

[0038] Preferably, the light source emitting module 210 is configured to control the intensity of the incident light. The incident light enters from one side of the test liquid storage tube 230, exits from the other side, and becomes transmitted light, which is received, detected, and output by the light detection module 220. The test liquid storage tube 230 is connected to the return liquid pipeline 120, so that the dialysate in the return liquid pipeline 120 is detected when it flows through the test liquid storage tube 230.

[0039] Furthermore, the light source emitting module 210 includes an electrically connected LED lamp and an LED driving circuit, and the light source inspection module includes an electrically connected light sensor and a detection circuit.

[0040] Furthermore, the urea detection device 200 also includes an emitting housing 211 and a detection housing 221, which together form a light-emitting cavity; the light source emitting module 210 is connected inside the emitting housing 211, the light detection module 220 is connected inside the detection housing 221, and the test liquid storage tube 230 passes through the light-emitting cavity and is connected between the emitting housing 211 and the detection housing 221.

[0041] In this technical solution, the setting of the light-emitting cavity avoids interference with the detection results from other light sources, thus ensuring the accuracy of the detection results of the light detection module 220.

[0042] Furthermore, the emitting housing 211 includes a bottom and a side wall connected to the bottom, the light source emitting module 210 is connected to the bottom, and the distance between the light source emitting module and the test liquid storage tube 230 is 2 to 5 times the diameter of the test liquid storage tube 230, for example, 3 times or 4 times.

[0043] In this technical solution, by setting an appropriate distance between the light source generation module and the storage tube under test, we can avoid uneven beam and excessively high local temperature of the dialysate caused by the distance being too close, while preventing the light from being severely attenuated or easily affected by the environment due to the distance being too large.

[0044] Furthermore, the detection housing 221 is provided with a limiting structure to limit the position of the light source emitting module 210; a collimating lens is provided between the light source emitting module 210 and the liquid storage tube 230 to be tested, and the collimating lens is connected to the detection housing 221.

[0045] In this technical solution, the collimating lens is used to make the light emitted by the light source emitting module 210 parallel light. Its setting ensures the uniformity of the light spot while preserving light intensity. Furthermore, the collimating lens allows for more flexible adjustment of the distance between the light source emitting module 210 and the test liquid storage tube 230, as long as the parallel light covers the cross-section of the portion of the test liquid storage tube 230 to be detected. In addition, the limiting structure ensures that each time the light source, such as an LED, is replaced, the light path passes through the expected position, improving installation efficiency and ensuring the accuracy of the detection results from the light detection module 220. The limiting structure (not shown in the figure) includes, but is not limited to, a limiting frame or limiting post connected to the detection housing 221.

[0046] Furthermore, the light source is ultraviolet light, and the wavelength of the ultraviolet light is 270nm~300nm, for example, 280nm or 290nm.

[0047] Furthermore, both the inlet pipe 110 and the return pipe 120 are equipped with flow control devices 400, the ultrafiltration pipe is connected to an ultrafiltration pump 310, and the test liquid storage tube 230 is made of transparent material, preferably a glass tube.

[0048] Furthermore, the detection housing 221 is also provided with a heat sink, and the dialyzer 100 is also provided with a blood inlet and a blood outlet. The blood inlet is connected to an inlet blood line, and the blood outlet is connected to an outlet blood line. A blood pump 500 is provided on the outlet blood line.

[0049] As a further preferred option, in order to calibrate the LED light, before the treatment begins, the inlet valve 111 is closed, the bypass valve 131 is opened, and the return valve 121 is closed. The dialysis waste fluid in the return line 120 does not contain urea nitrogen. At this time, the projected light value detected by the light detection module 220 is I. A0 During treatment, the inlet valve 111 is closed again, the bypass valve 131 is opened, and the return valve 121 is closed for inspection. At this time, the transmitted light value detected by the light detection module 220 is set to I. A1 , will I A1 with I A0 Compare the LEDs to determine if they have degraded. If degradation occurs, dynamically adjust the brightness of the ultraviolet LEDs to ensure that the incident light value is within I when there is no urea nitrogen. A0 Within the range.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. An on-line method for monitoring dialysis urea clearance, characterized by, The method comprises the following steps: S1, using a detection light source to irradiate dialysis waste liquid, and recording incident light intensity I0; S2, collecting initial transmitted light intensity I1 through the dialysis waste liquid, and transmitted light intensity at current time t I t , based on I1 and I t the ratio R of the post-dialysis urea nitrogen concentration and the pre-dialysis urea nitrogen concentration is calculated t ; S3, based on R t Calculate the urea clearance index Kt / V at the current time t t value.

2. The on-line monitoring method according to claim 1, characterized in that, When the dialysis liquid flow rate, blood flow rate or ultrafiltration volume changes, the current pre-dialysis urea nitrogen concentration and the ratio of pre-dialysis urea nitrogen concentration are calculated and recorded, and set as R1, and the initial transmitted light intensity I1 is recalibrated by the following calculation formula: 。 3. The on-line monitoring method according to claim 1, characterized in that, In step S2, the ratio R of the urea nitrogen concentration after dialysis to the urea nitrogen concentration before dialysis t The calculation formula is as follows: 。 4. The on-line monitoring method according to claim 1, characterized in that, In step S3, the urea removal index K at the current time t is calculated t / V t The calculation formula of the value is as follows: ， Wherein, UF is the ultrafiltration volume, and W is the body weight after ultrafiltration.

5. A computer system running a program using the online monitoring method of any one of claims 1-4, wherein the computer system is provided with an input interface of parameters and an output interface of results.

6. An on-line monitoring system of dialysis urea clearance, characterized in that, The application is suitable for the online monitoring method of any one of claims 1-4, comprising a dialyzer, wherein the dialyzer has a liquid inlet and a liquid outlet, the liquid inlet is connected with a liquid inlet pipeline, the liquid outlet is connected with a liquid outlet pipeline, the liquid outlet pipeline is connected with a urea detection device, the liquid outlet pipeline is provided with an ultrafiltration branch on the side far away from the dialyzer, and the ultrafiltration branch is provided with an ultrafiltration pump.

7. The on-line monitoring system of dialysis urea clearance rate according to claim 6, characterized in that, The liquid inlet pipeline and the liquid outlet pipeline are connected with a bypass pipeline, and the urea detector is arranged on the side far away from the dialyzer at the connection position of the bypass pipeline and the liquid outlet pipeline.

8. The on-line monitoring system of dialysis urea clearance rate according to claim 6, characterized in that, The bypass pipeline is provided with a bypass valve, the liquid inlet pipeline is provided with a liquid inlet valve, and the liquid inlet valve is arranged on the side close to the dialyzer at the bypass pipeline; the liquid outlet pipeline is provided with a liquid outlet valve, and the liquid outlet valve is arranged on the side close to the dialyzer at the bypass pipeline.

9. The on-line monitoring system of dialysis urea clearance rate according to claim 6, characterized in that, The urea detection device comprises a light source emitting module, a light detection module and a to-be-measured liquid storage tube, the light source emitting module is used to generate incident light to the to-be-measured liquid storage tube, the light detection module is used to receive and detect transmitted light through the to-be-measured liquid storage tube and output transmitted light intensity; The to-be-measured liquid storage tube is communicated with the liquid outlet pipeline.

10. The on-line monitoring system of dialysis urea clearance rate according to claim 6, characterized in that, The detection light source is ultraviolet light, and the light wave band of the ultraviolet light is 270-300 nm.

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