Hemodynamics monitoring system of intermittent occlusion balloon catheter and control method

Abstract

The invention discloses a hemodynamic monitoring system and a control method for an intermittent occlusion balloon catheter. The monitoring system comprises a blood flow pressure measurement module, a cardiac displacement measurement module, a thrombus monitoring module and an infusion pump control module. The control method comprises the steps that a right atrium and vena cava pressure threshold value is set, the size of a balloon is controlled and adjusted through an infusion pump, the relation between blood flow pressure and the pressure threshold value is continuously monitored, and then the expansion size and time of the balloon are fed back and adjusted; based on an automatic cold solution suction-discharge module, the cardiac displacement change is indirectly measured; in the treatment process, parameter changes such as cardiac displacement, right atrium pressure and vena cava pressure of a patient are measured, and whether the patient recovers hemodynamics or not is monitored, and safe machine withdrawal conditions are met; and the thrombus risk condition near the balloon is analyzed through the thrombus monitoring module. The size and time of the balloon are adjusted through pressure feedback, and the infusion precision is improved; and machine withdrawal judgment conditions are set, so that the treatment effect of the patient is improved.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a hemodynamic monitoring system and control method for an intermittent occlusion balloon catheter. Background Technology

[0002] The core pathological mechanism of acute decompensated heart failure (ADHF) lies in venous congestion. Approximately 60%-80% of ADHF patients still experience persistent congestion at discharge, a phenomenon closely associated with readmission risk and mortality. Traditional diuretic therapy has significant limitations, easily leading to diuretic resistance and potentially causing kidney damage; existing device therapies (such as ultrafiltration) have not yet significantly improved clinical outcomes. Against this backdrop, intermittent superior vena cava occlusion can effectively address these issues.

[0003] However, balloon catheters for intermittent superior vena cava occlusion have certain limitations in hemodynamic monitoring and control. Regarding balloon inflation controlled by the infusion pump, traditional methods lack a precise pressure feedback regulation mechanism, making it impossible to dynamically adjust balloon size and inflation time based on real-time hemodynamic changes in the patient. This makes it difficult to guarantee infusion accuracy; either the balloon over-inflates, increasing the burden on the heart and causing risks such as vascular rupture, or the balloon under-inflates, failing to achieve the expected therapeutic effect and affecting the patient's recovery process. Simultaneously, current technology relies primarily on the physician's experience and a single indicator when determining whether a patient is safe to wean off the catheter, lacking a comprehensive and objective assessment system. This can easily lead to premature or delayed weaning, increasing treatment risks and medical costs for the patient. Furthermore, during treatment, there is a lack of effective means to monitor thrombus formation; thrombus accumulation near the balloon is difficult to detect in a timely manner. Once a thrombus detaches, it can easily cause serious complications such as pulmonary embolism, endangering the patient's life.

[0004] Given the aforementioned problems with existing technologies, there is an urgent need to develop a more advanced and precise hemodynamic monitoring system and control method for intermittent occlusion balloon catheters, in order to achieve real-time and accurate monitoring and regulation of patient hemodynamics, improve infusion accuracy, reduce treatment risks, and provide patients with safer and more effective treatment options. Summary of the Invention

[0005] The purpose of this invention is to provide a hemodynamic monitoring system and control method for intermittent occlusion balloon catheters.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A hemodynamic monitoring system for an intermittent occlusion balloon catheter, the intermittent occlusion balloon catheter comprising a catheter body, a large balloon and a small balloon disposed on the catheter body, and external extension lines extending from the inside of the catheter body: a large balloon external extension line, a small balloon external extension line, a proximal external extension line, a distal external extension line, and a temperature measurement external extension line; the large balloon external extension line is connected to a balloon infusion pump; the proximal external extension line is connected to a cold solution infusion pump.

[0008] The monitoring system includes a pressure measurement module, a cardiac output measurement module, an infusion pump control module, and a thrombosis monitoring module.

[0009] The pressure measurement module obtains pressure through pressure sensors connected to the balloon catheter. There are two pressure sensors, which are used to collect the pressure of the right atrium and superior vena cava in real time. They are connected to the proximal external extension line and the distal external extension line, respectively, in vitro.

[0010] The cardiac output measurement module indirectly measures the output through temperature sensors. There are two temperature sensors: the first temperature sensor is a thermistor, which is implanted in the balloon catheter to measure the real-time temperature of the blood and is connected to the monitoring system through an external temperature measurement extension line; the second temperature sensor is located outside the body and measures the real-time temperature of the cold solution.

[0011] The thrombosis monitoring module indirectly measures blood deposition and aggregation by installing fiber optic sensors on the surface of the balloon catheter and measuring changes in light signals.

[0012] The infusion pump control module is used to control the balloon infusion pump and the cold solution infusion pump respectively, thereby controlling the balloon inflation-contraction and cold solution injection process.

[0013] According to one aspect of the invention, the monitoring system further includes a power supply module, a signal acquisition module, a balloon actuation module, a communication module, and a watchdog circuit controlled by a core control unit;

[0014] The power module includes a main power supply module and a backup battery module, wherein the backup battery module is equipped with at least two lithium batteries; when the main power supply module fails, the backup battery module can support the monitoring system to continue working for at least 12 hours.

[0015] The signal acquisition modules are all implemented through sensor measurements. The electrical signals obtained by the sensors are converted into digital signals through low-pass filtering, signal amplification, and ADC sampling.

[0016] A timer is set in the balloon execution module to display the inflation or contraction time of the large balloon in real time;

[0017] The communication module has functions of data interaction, sensor driving, sensor fault detection, and security control.

[0018] According to one aspect of the invention, a thermistor and a fixed resistor are connected in series to form a voltage divider, and the formula for calculating the fixed resistor is as follows:

[0019]

[0020] Among them, the thermistors are selected with resistance values ​​RTL, RTM and RTH corresponding to three temperatures: low temperature TL, intermediate temperature TM and high temperature TH. The low temperature TL, intermediate temperature TM and high temperature TH need to satisfy the arithmetic sequence rule, that is, TL+TH=2TM.

[0021] According to one aspect of the invention, the thermistor output voltage U out The relationship between U and the actual blood temperature Tb is out =k*Tb+b is a linear function of the first degree.

[0022] According to one aspect of the present invention, the large balloon is provided with a plurality of fiber optic sensors arranged symmetrically in an even number on the side near the jugular vein.

[0023] This invention provides a hemodynamic control method for intermittently occluded balloon catheters using the aforementioned monitoring system, the control method comprising the following steps:

[0024] (1) Set the pressure thresholds for the right atrium and vena cava, control and adjust the balloon size through the balloon infusion pump, and continuously monitor the relationship between blood flow pressure and the above pressure thresholds, thereby providing feedback to adjust the balloon inflation size and time.

[0025] (2) Based on the control module for automatic aspiration and discharge of cold solution, the change in cardiac output is indirectly measured; the cold solution infusion pump automatically aspirates a certain volume of cold solution from the cold solution container through the first one-way valve; after stopping for 2-3 seconds, the cold solution infusion pump pushes the piston forward to discharge the cold solution, which then passes through the second one-way valve into the right atrium; after completing one cycle, the cardiac output is measured periodically and continuously according to the measurement interval.

[0026] (3) Measure the changes in cardiac output, right atrial pressure and vena cava pressure during the treatment process, and monitor whether the patient has recovered hemodynamics and is ready for safe weaning.

[0027] (4) The thrombosis risk near the balloon is analyzed by the thrombosis monitoring module. The fiber optic sensor determines the thrombosis risk by monitoring the fibrinogen concentration. If the fibrinogen concentration is greater than the threshold of 4.5 g / L, the large balloon contraction operation needs to be performed.

[0028] According to one aspect of the invention, in step (1), the large balloon has three different states: fully contracted, partially inflated, and fully inflated; the step of adjusting the balloon inflation size is as follows:

[0029] The large balloon is initially in a semi-inflated state, with threshold values ​​for right atrial and superior vena cava pressures set at 0-10 mmHg and 5-40 mmHg, respectively. Real-time pressure data of the right atrium and superior vena cava are collected via a pressure measurement module and compared with the threshold values. If the right atrial pressure is less than 0 mmHg or the superior vena cava pressure is greater than 40 mmHg, the balloon contraction process is initiated. If the right atrial pressure is greater than 5 mmHg or the superior vena cava pressure is between 20-40 mmHg, the large balloon inflation process is initiated. After the balloon's state changes, the right atrial and superior vena cava pressures are monitored to see if they return to the threshold range. If the threshold requirements are still not met, the balloon contraction or inflation time needs to be further extended. The rate of volume change during the balloon's inflation or contraction process is no higher than 0.5 mL / s. After multiple adjustments to the balloon's volume, if the pressure returns to the threshold range, the current balloon state is maintained.

[0030] According to one aspect of the present invention, in step (3), the method for determining the safe weaning conditions is as follows: after the large balloon has been kept in a fully contracted state for 6 hours, the weaning determination procedure is initiated; it is determined whether the right atrial pressure is between 0-5 mmHg, the superior vena cava pressure is between 0-10 mmHg, and the cardiac output is greater than 4.5 L / min; if the patient's hemodynamics meet the above three conditions at the same time, the balloon catheter is withdrawn and the treatment is terminated; if any one of the conditions is not met, treatment needs to continue.

[0031] According to one aspect of the present invention, the volume expansion process of the large balloon includes four time periods: balloon expansion T1, balloon holding in an expanded state T2, balloon contraction T3, and balloon holding in a contracted state T4; the balloon expansion T1 is set within the range of 5-10s, the balloon holding in an expanded state T2 is set within the range of 5-20min, the balloon contraction T3 is set within the range of 20-40s, and the balloon holding in a contracted state T4 is set within the range of 15-30s.

[0032] According to one aspect of the invention, the correction coefficient for cardiac output is set in the range of 0.5-1.5.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] This invention proposes a hemodynamic monitoring system and control method for intermittent occlusion balloon catheters. The monitoring system includes four modules: hemodynamic pressure measurement, cardiac output measurement, thrombus monitoring, and infusion pump control. Through pressure feedback, it precisely adjusts the balloon inflation size and timing, thereby improving the infusion accuracy of large balloons and cold solutions, thus reducing patient treatment risks. Furthermore, this invention proposes quantitative criteria for weaning, effectively ensuring the patient's hemodynamics return to normal, changing the reliance on clinical experience or qualitative judgment, and significantly improving treatment outcomes. Additionally, the thrombus monitoring module can monitor the thrombus risk during balloon occlusion in real time, thereby reducing the probability of hemocompatibility complications in patients. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the implantation of an intermittent occlusion balloon catheter provided in an embodiment of the present invention (dashed lines represent electrical connections, and solid lines represent tubing connections).

[0036] Figure 2 This is a schematic diagram of the hemodynamic monitoring system provided in the embodiment of the present invention.

[0037] Figure 3 This is a hardware connection diagram of the hemodynamic monitoring system provided in an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of the thermistor linearization process provided in an embodiment of the present invention.

[0039] Figure 5 This is the linearization curve of the thermistor provided in the embodiment of the present invention.

[0040] Figure 6 This is a flowchart of the pressure feedback regulation control of the large balloon state provided in an embodiment of the present invention.

[0041] Figure 7 This is a flowchart for determining whether the machine can be removed, provided in an embodiment of the present invention.

[0042] Figure 8 This is a schematic diagram illustrating the change in the volume of a large balloon over time during a specific period, as provided in an embodiment of the present invention.

[0043] Figure 9 This is a flowchart of continuous monitoring of cardiac flow provided in an embodiment of the present invention.

[0044] Figure 10 This is a schematic diagram of the in vivo sensor installation of the thrombosis monitoring module provided in an embodiment of the present invention. Detailed Implementation

[0045] The embodiments of this invention will now be described in detail, as illustrated in the accompanying drawings. In the following description, when referring to the drawings, unless otherwise stated, the same numerals in different drawings denote the same or similar structures.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this specification, "a plurality of" means two or more, unless otherwise expressly specified. The terms "connection" and "linkage" described in this specification, unless otherwise specified, include both direct and indirect connections (linkages). Additionally, the terms "comprising," "having," and any other variations are intended to cover non-exclusive inclusion. For example, a process, method, software, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units but also includes steps or units not listed, or other steps or units inherent to such processes, methods, products, or apparatus.

[0047] In this instruction manual, "proximal" is defined as the end closer to the operator, while "distal" is defined as the end further away from the operator, that is, the end closer to the patient's heart.

[0048] refer to Figure 1As shown, the intermittent occlusion balloon catheter 1 is implanted via jugular vein puncture and passes through the superior vena cava (SVC), right atrium (RA), right ventricle (RV), and pulmonary artery (PA). The intermittent occlusion balloon catheter 1 includes a large balloon 11, a large balloon external extension 12, a proximal external extension 13, a distal external extension 14, a temperature measurement external extension 15, a small balloon external extension 16, a small balloon 17, and a catheter body 18. The large balloon external extension 12, proximal external extension 13, distal external extension 14, temperature measurement external extension 15, and small balloon external extension 16 are all connected to the end of the catheter body 18 via injection-molded heads. The large balloon external extension line 12 is connected to the syringe of the large infusion pump 2 (i.e., balloon infusion pump) through a tubing; similarly, the small infusion pump 3 (i.e., cold solution infusion pump) is connected to the proximal external extension line 13 and the cold solution container 5 through tubing, and a first one-way valve 51, a second one-way valve 52, and a three-way valve 53 are respectively provided on the tubing. The balloon catheter 1 is connected to the monitoring system 4 via a first lead 41, a second lead 42, a third lead 43, a fourth lead 44, a fifth lead 45, a sixth lead 46, and a seventh lead 47. Specifically, the large infusion pump 2 is connected to the monitoring system via the first lead 41; the distal external extension cable 14 is connected to the monitoring system via the second lead 42; the temperature measurement external extension cable 15 is connected to the monitoring system via the third lead 43; the small infusion pump 3 is connected to the monitoring system via the fourth lead 44; the three-way valve 53 is connected to the monitoring system via the fifth lead 45 and the sixth lead 46, where the fifth lead 45 is used to monitor the pressure of the proximal external extension cable drainage, and the sixth lead 46 is used to monitor the temperature of the cold solution; and the fiber optic sensor installed in the balloon catheter is connected to the monitoring system via the seventh lead 47.

[0049] refer to Figure 2 As shown, monitoring system 4 includes a pressure measurement module, a cardiac output measurement module, an infusion pump control module, and a thrombosis monitoring module. The pressure measurement module obtains data via a pressure sensor connected to the balloon catheter. The pressure sensor can be an implantable miniature sensor or a disposable external pressure sensor. Combined with... Figure 1 As shown, the monitoring system 4 of this invention includes two pressure measurement points, namely two pressure sensors connected externally to the proximal external extension line 13 and the distal external extension line 14, respectively. This configuration allows for the acquisition of pressure data from the right atrial RA, pulmonary artery PA, or superior vena cava SVC when the balloon catheter 1 is implanted in the patient. The cardiac output measurement module is primarily based on the thermodilution principle, using a temperature sensor for indirect measurement. Combined with... Figure 1As shown, two temperature sensors are provided. The first temperature sensor, a thermistor 151, is implanted inside the balloon catheter to measure the real-time temperature of the blood and is then connected to the monitoring system 4 via an external temperature measurement extension cable 15. The second temperature sensor is located externally and is connected to a three-way valve 53 to measure the real-time temperature of the cold solution. The thrombosis monitoring module indirectly measures blood deposition and aggregation by measuring changes in light signals through a fiber optic sensor installed on the surface of the balloon catheter, thereby reflecting the risk of thrombosis in real time. The infusion pump control module is used to control the large infusion pump 2 (i.e., the balloon infusion pump) and the small infusion pump 3 (i.e., the cold solution infusion pump) respectively, which can precisely control the expansion and contraction of the large balloon and the injection of the cold solution.

[0050] refer to Figure 3 As shown, the power supply module of monitoring system 4 includes a main power supply module and a backup battery module. The backup battery module should have at least two lithium batteries. In the event of a failure of the main power supply module, the backup battery module should be able to support the monitoring system 4 for at least 12 hours of continued operation. The power supply module supplies power to the core control unit, which can be a microcontroller, embedded processor, or industrial-grade PLC. The core control unit controls the signal acquisition module, balloon execution module, communication module, and watchdog circuit. The signal acquisition module uses sensor measurements. The electrical signals obtained by the sensors are converted into digital signals through low-pass filtering, signal amplification, and ADC sampling. A timer is set under the balloon execution module to display the inflation or deflation time of the large balloon 11 in real time. The communication module needs to have data interaction capabilities, with a USB interface for easy data reading and retrieval of past records, including historical pressure values, historical cardiac output, historical balloon inflation-deflation status, thrombosis monitoring history, and other alarm and fault information. The sensor fault monitoring module is mainly used for sensor calibration and abnormal value alarms before the monitoring system starts. The communication module can also be connected to external devices, such as ultrasound probes, for multi-parameter auxiliary monitoring. The balloon actuation module performs precise control based on the signal acquisition channel data, enabling the monitoring system 4 to have a more agile adjustment function for the balloon catheter.

[0051] refer to Figure 4 As shown, blood temperature T b Indirect measurement is performed using a thermistor 151. Because the temperature-resistance relationship of a thermistor is non-linear, it is difficult to incorporate the temperature-resistance relationship into the monitoring system program using complex curve formulas or interpolation methods. Therefore, to improve measurement accuracy and program editing operability, this invention connects a fixed resistor 152 in series with the thermistor 151. A voltage U is applied between pins Pin1 and Pin3. in The voltage divider U between pins 2 and 3 of the thermistor 151 is measured. out .

[0052] The resistance value of the fixed resistor 152 is determined by the temperature measurement range, and the specific calculation formula is as follows:

[0053]

[0054] Among them, R TL R TM R TH These represent the resistance values ​​of the thermistor at low temperature TL, intermediate temperature TM, and high temperature TH, respectively. In practical applications, if the intermediate temperature TM of the thermistor is set to 37℃, then the resistance value R at 37℃ is... TM The selectable temperature range for the resistor is 0-74℃, which is 14.015kΩ. TL，0℃ =62.9kΩ, R TH,74℃ = 4.17kΩ. Therefore, using the above formula, the fixed resistor R = 10.63kΩ. Here, R... TL R TM R TH The corresponding temperatures should form an arithmetic sequence, such as 0℃, 37℃, 74℃ or 0℃, 50℃, 100℃, etc.

[0055] refer to Figure 4 and Figure 5 As shown in Figure B, the temperature-resistance relationship of thermistor 151 is non-linear. By connecting thermistor 151 and fixed resistor 152 in series for voltage division, and then at U... in If a 5V voltage is input, then U out It exhibits a nearly linear relationship with temperature, reference Figure 5 A. This method transforms the nonlinear temperature-resistance relationship into a linear temperature-output voltage relationship, and then uses a linear function U... out =k*Tb+b is written into monitoring system 4. For example, in this invention, after series voltage division, the relationship between temperature and output voltage in the 0-74℃ range is: U out = -0.04*Tb+4.36, meaning the coefficients k and b are -0.04 and 4.36 respectively, resulting in a goodness of fit of 0.99. Similarly, the voltage across the pins of the fixed resistor 152 can also be set as the output voltage U. out .

[0056] Reference and combination Figure 1 and Figure 6As shown, the large balloon 11 is placed within the superior vena cava (SVC) and is 1-2 cm away from the right atrium (RA). The large balloon 11 can be in three states: fully contracted, partially inflated, and fully inflated. The partially inflated state is dynamic, meaning it is not fixed at a specific volume; it is considered partially inflated whenever it is not fully contracted or fully inflated. A fully inflated balloon 11 must completely block the superior vena cava (SVC) without leaving any gaps between it and the vessel wall. In this invention, the inflation size and inflation time of the large balloon 11 are adjusted through pressure feedback. The pressure here mainly refers to the superior vena cava pressure and the right atrium pressure. The balloon contraction time and inflation time refer to the time the balloon remains in a certain contracted or inflated state, during which time the balloon volume does not change. The specific steps for adjusting the balloon size through pressure feedback are as follows:

[0057] S01: The large balloon 11 is initially in a semi-inflated state, and the threshold values ​​for right atrial and superior vena cava pressures are set to 0-10 mmHg and 5-40 mmHg, respectively;

[0058] S02: Collect real-time pressure data of the right atrium and superior vena cava through the pressure module and compare it with the threshold in step S01;

[0059] S03: If the right atrial pressure is less than 0 mmHg or the superior vena cava pressure is greater than 40 mmHg, the balloon contraction process needs to be initiated; if the right atrial pressure is greater than 5 mmHg or the superior vena cava pressure is between 20-40 mmHg, the large balloon inflation process needs to be initiated.

[0060] S04: After the large balloon changes state, monitor whether the pressure in the right atrium and superior vena cava returns to the threshold range. If the threshold setting is still not met, the balloon contraction or inflation time needs to be further extended. Here, the volume change rate of the large balloon 11 is no higher than 0.5 mL / s.

[0061] S05: After adjusting the volume of the large balloon multiple times, if the pressure returns to the threshold range, the current state of the large balloon is maintained.

[0062] Pressure feedback regulation of the balloon's inflation state can prevent prolonged superior vena cava occlusion, which could lead to elevated superior vena cava pressure and severely reduce right atrial pressure, thus decreasing blood return. Conversely, prolonged balloon occlusion can also cause blood pooling, increasing the risk of thrombosis. Conversely, if the balloon remains in a constricted state for too long, its therapeutic effect on heart failure will be minimal. To ensure the reliability of the monitoring system, the balloon's induction criteria should simultaneously meet the set thresholds for right atrial and superior vena cava pressure.

[0063] refer to Figure 7As shown, if the patient's hemodynamic parameters remain within the normal range for 6 hours after the large balloon has fully contracted, then the conditions for weaning balloon catheter 1 are met. The specific procedure is as follows:

[0064] S01: Six hours after the large balloon 11 has fully contracted, the weaning procedure is initiated.

[0065] S02: Determine whether the right atrial pressure is between 0-5 mmHg, the superior vena cava pressure is between 0-10 mmHg, and the cardiac output is greater than 4.5 L / min; if the patient's hemodynamics meet all three conditions, withdraw the balloon catheter and terminate the treatment.

[0066] S03: If the conditions are not met, treatment needs to continue.

[0067] refer to Figure 8 As shown, the inflation volume of the large balloon 11 includes four time periods: balloon inflation (T1), balloon inflation maintenance (T2), balloon contraction (T3), and balloon contraction (T4). The inflation period (T1) is set within 5-10 seconds, the inflation maintenance period (T2) within 5-20 minutes, the contraction period (T3) within 20-40 seconds, and the contraction period (T4) within 15-30 seconds. The volume of the large balloon 11 should be set to 5-10 mL, and all air should be expelled from the balloon during inflation.

[0068] refer to Figure 9 As shown, cardiac output was measured using the thermal dilution method, and the specific steps are as follows:

[0069] S01: Activate the cardiac flow test function and set the correction coefficient, cold solution volume, and injection speed;

[0070] S02: The small infusion pump fills the cold solution to the set volume;

[0071] S03: A small infusion pump discharges cold solution and simultaneously measures the temperature of blood and cold solution;

[0072] S04: After the small infusion pump completes the operation of discharging the cold solution, calculate the cardiac output value;

[0073] S05: In order to monitor changes in cardiac output at regular intervals, it is necessary to set a measurement interval. After the interval is reached, repeat the above operation to measure cardiac output and save the record.

[0074] In this invention, to enable regular monitoring of changes in cardiac output during patient treatment, a control module is provided that can automatically aspirate and drain cold solution. Combined with... Figure 1As shown, the small infusion pump 3 uses a syringe with a volume of 5 or 10 mL and connects it to the proximal external extension line 13 and the cold solution container 5. Both the cold solution container 5 and the proximal external extension line 13 are equipped with a first one-way valve 51 and a second one-way valve 52. When the cardiac flow test function is activated, the small infusion pump 3 automatically draws a certain volume of cold solution from the cold solution container 5 through the first one-way valve 51; after stopping for 2-3 seconds, the small infusion pump 3 pushes the piston forward to expel the cold solution, which then passes through the second one-way valve 52 into the right atrium. After completing one cycle, cardiac output is measured periodically according to the measurement interval.

[0075] In this invention, the injection speed of the small infusion pump 3 is 3-5 seconds and needs to be set to uniform motion; the cardiac output measurement interval is 30 minutes, 60 minutes, or 90 minutes, etc.; the cold solution can be physiological saline, glucose, or other solutions, and the temperature does not exceed 5°C. Therefore, the cold solution container 5 needs to be stored in a low-temperature constant-temperature bath. The correction coefficient is set between 0.5 and 1.5, and the specific value is related to the injection speed, cold solution temperature, etc.

[0076] refer to Figure 10 As shown, when the large balloon 11 is fully inflated and occludes the superior vena cava, blood cannot flow into the right atrium through the superior vena cava. This causes blood stasis in the blood flow area, potentially leading to complications such as thrombosis. To enable real-time monitoring of thrombosis risk and reduce the probability of complications during treatment, [further details are needed]. Figure 10 As shown, multiple fiber optic sensors are positioned on the side of the large balloon 11 near the jugular vein. These sensors indirectly identify thrombosis risk by emitting light signals that bind to blood components. Fiber optic sensors 471 are symmetrically arranged on one side of the proximal end of the large balloon 11, in even numbers (2, 4, 6, etc.), and transmit data to the monitoring system 4 via a seventh wire 47. In this invention, the fiber optic sensors 471 can indirectly assess the risk of thrombosis by identifying blood components such as fibrinogen, thrombin, or other platelet activation markers. For example, when fibrinogen binds to molecular probes on the surface of an optical fiber, it causes changes in optical parameters such as the refractive index of the fiber surface, thus affecting the propagation characteristics of light waves. The fiber optic sensor 471 can sense this change to reflect changes in fibrinogen levels, and elevated fibrinogen levels are often associated with an increased risk of thrombosis. If the fiber optic sensor 471 detects a fibrinogen concentration higher than the threshold of 4.5 g / L, the volume of the large balloon 11 needs to be reduced briefly. In addition to the methods described above for monitoring thrombosis, a small hole can be made on the side of the catheter body 18 near the proximal end of the large balloon 11, and anticoagulant or flushing fluid can be injected through the hole to reduce the risk of blood stasis or reactivation. Since this method requires increasing the number of lumens in the balloon catheter 1, which may increase the outer diameter of the catheter body 18, it will not be described in detail in this invention.

[0077] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A hemodynamic monitoring system for intermittently occluded balloon catheters, characterized in that, The intermittent occlusion balloon catheter includes a catheter body, a large balloon and a small balloon disposed on the catheter body, and external extension lines extending from the inside of the catheter body: a large balloon external extension line, a small balloon external extension line, a proximal external extension line, a distal external extension line, and a temperature measurement external extension line; the large balloon external extension line is connected to a balloon infusion pump; the proximal external extension line is connected to a cold solution infusion pump. The monitoring system includes a pressure measurement module, a cardiac output measurement module, an infusion pump control module, and a thrombosis monitoring module. The pressure measurement module obtains pressure through pressure sensors connected to the balloon catheter. There are two pressure sensors, which are used to collect the pressure of the right atrium and superior vena cava in real time. They are connected to the proximal external extension line and the distal external extension line, respectively, in vitro. The cardiac output measurement module indirectly measures the output through temperature sensors. There are two temperature sensors: the first temperature sensor is a thermistor, which is implanted in the balloon catheter to measure the real-time temperature of the blood and is connected to the monitoring system through an external temperature measurement extension line; the second temperature sensor is located outside the body and measures the real-time temperature of the cold solution. The thrombosis monitoring module indirectly measures blood deposition and aggregation by installing fiber optic sensors on the surface of the balloon catheter and measuring changes in light signals. The infusion pump control module is used to control the balloon infusion pump and the cold solution infusion pump respectively, thereby controlling the balloon inflation-contraction and cold solution injection process.

2. The hemodynamic monitoring system for intermittent occlusion balloon catheters according to claim 1, characterized in that, The monitoring system also includes a power module, and a signal acquisition module, a balloon execution module, a communication module, and a watchdog circuit controlled by a core control unit; The power module includes a main power supply module and a backup battery module, wherein the backup battery module is equipped with at least two lithium batteries; when the main power supply module fails, the backup battery module can support the monitoring system to continue working for at least 12 hours. The signal acquisition modules are all implemented through sensor measurements. The electrical signals obtained by the sensors are converted into digital signals through low-pass filtering, signal amplification, and ADC sampling. A timer is set in the balloon execution module to display the inflation or contraction time of the large balloon in real time; The communication module has functions of data interaction, sensor driving, sensor fault detection, and security control.

3. The hemodynamic monitoring system for intermittent occlusion balloon catheters according to claim 1, characterized in that, A thermistor and a fixed resistor are connected in series to form a voltage divider. The formula for calculating the value of the fixed resistor is: Among them, the thermistors are selected with resistance values ​​RTL, RTM and RTH corresponding to three temperatures: low temperature TL, intermediate temperature TM and high temperature TH. The low temperature TL, intermediate temperature TM and high temperature TH need to satisfy the arithmetic sequence rule, that is, TL+TH=2TM.

4. The hemodynamic monitoring system for intermittent occlusion balloon catheters according to claim 3, characterized in that, The thermistor output voltage U out The relationship between U and the actual blood temperature Tb is out =k*Tb+b is a linear function of the first degree.

5. The hemodynamic monitoring system for intermittent occlusion balloon catheters according to claim 1, characterized in that, The large balloon is equipped with multiple fiber optic sensors arranged symmetrically on the side near the jugular vein, with an even number of sensors.

6. A hemodynamic control method for an intermittently occluded balloon catheter, employing the monitoring system described in any one of claims 1-5, the control method comprising the following steps: (1) Set the pressure thresholds for the right atrium and vena cava, control and adjust the balloon size through the balloon infusion pump, and continuously monitor the relationship between blood flow pressure and the above pressure thresholds, thereby providing feedback to adjust the balloon inflation size and time. (2) Based on the control module for automatic aspiration and discharge of cold solution, the change in cardiac output is indirectly measured; the cold solution infusion pump automatically aspirates a certain volume of cold solution from the cold solution container through the first one-way valve; after stopping for 2-3 seconds, the cold solution infusion pump pushes the piston forward to discharge the cold solution, which then passes through the second one-way valve into the right atrium; after completing one cycle, the cardiac output is measured periodically and continuously according to the measurement interval. (3) Measure the changes in cardiac output, right atrial pressure and vena cava pressure during the treatment process, and monitor whether the patient has recovered hemodynamics and is ready for safe weaning. (4) The thrombosis risk near the balloon is analyzed by the thrombosis monitoring module. The fiber optic sensor determines the thrombosis risk by monitoring the fibrinogen concentration. If the fibrinogen concentration is greater than the threshold of 4.5 g / L, the large balloon contraction operation needs to be performed.

7. The hemodynamic control method for intermittent occlusion balloon catheters according to claim 6, characterized in that, In step (1), the large balloon has three different states: fully contracted, partially inflated, and fully inflated; the steps for adjusting the balloon inflation size are as follows: The large balloon is initially in a semi-inflated state, and the threshold values ​​for right atrial and superior vena cava pressure are set to 0-10 mmHg and 5-40 mmHg, respectively. Real-time pressure data of the right atrium and superior vena cava are collected by the pressure measurement module and compared with the threshold values. If the right atrial pressure is less than 0 mmHg or the superior vena cava pressure is greater than 40 mmHg, the balloon contraction process needs to be initiated. If the right atrial pressure is greater than 5 mmHg or the superior vena cava pressure is between 20-40 mmHg, the large balloon inflation process needs to be initiated. After the balloon's state changes, monitor whether the pressure in the right atrium and superior vena cava returns to the threshold range. If the threshold setting is still not met, the balloon's contraction or inflation time needs to be further extended. The rate of volume change during the balloon's inflation or contraction should not exceed 0.5 mL / s. After adjusting the balloon's volume multiple times, if the pressure returns to the threshold range, maintain the balloon's current state.

8. The hemodynamic control method for intermittent occlusion balloon catheters according to claim 6, characterized in that, In step (3), the method for determining the safe weaning conditions is as follows: after the large balloon has been in a fully contracted state for 6 hours, the weaning determination procedure is initiated; it is determined whether the right atrial pressure is between 0-5 mmHg, the superior vena cava pressure is between 0-10 mmHg, and the cardiac output is greater than 4.5 L / min; if the patient's hemodynamics meet the above three conditions at the same time, the balloon catheter is withdrawn and the treatment is terminated; if any one of the conditions is not met, treatment needs to continue.

9. The hemodynamic control method for intermittent occlusion balloon catheters according to claim 6, characterized in that, The expansion process of the large balloon includes four time periods: balloon expansion (T1), balloon inflated state (T2), balloon contraction (T3), and balloon contraction state (T4). The balloon expansion process (T1) is set within the range of 5-10 seconds, the balloon inflated state (T2) is set within the range of 5-20 minutes, the balloon contraction process (T3) is set within the range of 20-40 seconds, and the balloon contraction state (T4) is set within the range of 15-30 seconds.

10. The hemodynamic control method for an intermittent occlusion balloon catheter according to claim 6, characterized in that, The correction coefficient for cardiac output is set in the range of 0.5-1.5.

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