Method for identifying model of thermal dilution catheter and system for measuring hemodynamic parameters

Abstract

According to the thermal dilution catheter model identification method, a first pin of a thermal dilution catheter is connected with one end of a first resistor and one end of a third resistor, the other end of the first resistor is connected with a third pin, the other end of the third resistor is connected with one end of a second resistor and a second pin, and the other end of the second resistor is connected with a fourth pin; the third pin and the second pin are conducted, so that the first resistor and the third resistor are connected in parallel; supplying power to the first pin and / or the fourth pin to form a voltage difference between the first pin and the fourth pin; obtaining resistance values of the first resistor, the second resistor and the third resistor; based on the resistance values of the first resistor, the second resistor and the third resistor and the voltage difference between the first pin and the fourth pin, calculating a target voltage value of parallel connection of the first resistor and the third resistor; and identifying the model of the heat dilution catheter based on the target voltage value and the corresponding relationship between the preset voltage value and the model of the heat dilution catheter. The purpose of identifying the model of the heat dilution catheter is achieved.

Description

Technical Field

[0001] The invention relates to the field of medical devices, and in particular to a method for identifying a thermal dilution catheter model and a system for measuring hemodynamic parameters. Background Art

[0002] The monitor can continuously monitor the patient's physiological parameters, detect changing trends, point out critical situations, and provide doctors with a basis for emergency treatment and treatment. However, in actual use, the monitor and the thermodilution catheter cannot recognize the model, and medical staff can only identify the relevant model of the thermodilution catheter themselves. Due to the heavy workload of medical staff every day, if they are not careful, they will misidentify the model of the thermodilution catheter, which has brought considerable resistance to existing medical work.

[0003] Therefore, how to enable the monitor to autonomously identify the model of the thermal dilution catheter is an urgent problem to be solved. Summary of the invention

[0004] The main technical problem solved by the present invention is how to realize the monitor to autonomously identify the model of the thermal dilution catheter.

[0005] According to a first aspect, an embodiment provides a method for identifying a model of a thermal dilution catheter, which is applied to a thermal dilution catheter, wherein the thermal dilution catheter comprises a first resistor, a second resistor, a third resistor, a first pin, a second pin, a third pin and a fourth pin, wherein the first pin is connected to one end of the first resistor and one end of the third resistor, the other end of the first resistor is connected to the third pin, the other end of the third resistor is connected to one end of the second resistor and the second pin, and the other end of the second resistor is connected to the fourth pin; the identification method comprises:

[0006] Connecting the third pin to the second pin so that the first resistor and the third resistor are connected in parallel;

[0007] supplying power to the first pin and / or the fourth pin so that a voltage difference is formed between the first pin and the fourth pin;

[0008] Obtaining resistance values ​​of the first resistor, the second resistor, and the third resistor;

[0009] Based on the resistance values ​​of the first resistor, the second resistor and the third resistor, and the voltage difference between the first pin and the fourth pin, a target voltage value of the first resistor and the third resistor in parallel is calculated;

[0010] Based on the correspondence between the target voltage value and the preset voltage value and the model of the thermal dilution catheter, the model of the thermal dilution catheter is identified.

[0011] According to a second aspect, an embodiment provides a system for measuring hemodynamic parameters, the system comprising:

[0012] Monitors, syringes, injection temperature sensors, central venous pressure sensors, arterial pressure sensors, central venous catheters, and thermodilution catheters;

[0013] The injection liquid temperature sensor is used to detect the temperature of the liquid output by the syringe, and output the detected temperature to the monitor;

[0014] The arterial pressure sensor is used to detect the arterial blood pressure after the thermodilution catheter inputs the liquid into the patient's body, and output the arterial blood pressure to the monitor;

[0015] The central venous pressure sensor is used to detect the central venous pressure after the central venous catheter is inserted into the patient's body, and output the central venous pressure to the monitor;

[0016] The monitor is used to calculate hemodynamic parameters based on the temperature, the arterial blood pressure and the central venous pressure.

[0017] According to the above-mentioned embodiment, a method for identifying the model of a thermodilution catheter is provided by connecting the first resistor and the third resistor of the thermodilution catheter in parallel and forming a voltage difference between the first pin and the fourth pin of the thermodilution catheter, thereby obtaining the resistance values ​​of the first resistor, the second resistor, and the third resistor of the thermodilution catheter and the voltage difference between the first pin and the fourth pin, and calculating the target voltage value of the first resistor and the third resistor in parallel, and determining the model corresponding to the thermodilution catheter according to whether the target voltage value matches the preset voltage value. In this way, the efficiency and accuracy of identifying the model of the thermodilution catheter are improved, and the possibility of operation errors by medical staff is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic flow chart of a method for identifying a thermodilution catheter model provided in this embodiment;

[0019] Figure 2 A schematic diagram of a resistance of the thermal dilution catheter provided in this embodiment;

[0020] Figure 3 A schematic diagram of the structure of the thermal dilution end of the thermal dilution catheter provided in this embodiment;

[0021] Figure 4 Another resistance schematic diagram of the thermal dilution catheter provided in this embodiment;

[0022] Figure 5 A structural block diagram of a system for measuring hemodynamic parameters provided in this embodiment;

[0023] Figure 6 A schematic diagram of a blood temperature change curve monitored by the thermodilution end of the thermodilution catheter provided in this embodiment;

[0024] Figure 7 A schematic diagram of a femoral artery blood pressure change curve monitored by the pressure end of the thermodilution catheter provided in this embodiment;

[0025] Figure 8 A cross-sectional view of the injection liquid temperature sensor and the injection liquid temperature sensor connecting cable provided in this embodiment;

[0026] Fig. 9 A schematic diagram of the injection liquid temperature sensor and the injection liquid temperature sensor connecting cable provided in this embodiment for use in combination;

[0027] Fig.10 This is a schematic diagram of the disassembled structure of the injection liquid temperature sensor provided in this embodiment. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0029] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0030] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0031] At present, the monitor can continuously monitor the patient's physiological parameters, detect the trend of change, point out the critical situation, and provide doctors with a basis for emergency treatment and treatment. However, in actual use, the monitor and the thermal dilution catheter cannot recognize the model, and the medical staff can only identify the relevant model of the thermal dilution catheter by themselves. Due to the heavy workload of medical staff every day, if they are not careful, they will misidentify the model of the thermal dilution catheter, which brings considerable resistance to existing medical work. Therefore, how to realize the monitor's autonomous recognition of the thermal dilution catheter model is an urgent problem to be solved.

[0032] Based on this, the scheme of the present invention is proposed. In the embodiment of the present invention, the first resistor and the third resistor of the thermal dilution catheter are connected in parallel, and a voltage difference is formed between the first pin and the fourth pin of the thermal dilution catheter, so that the target voltage value of the first resistor and the third resistor in parallel is calculated on the basis of obtaining the resistance values ​​of the first resistor, the second resistor, and the third resistor of the thermal dilution catheter and the voltage difference between the first pin and the fourth pin, and the model corresponding to the thermal dilution catheter is determined according to whether the target voltage value matches the preset voltage value. In this way, the efficiency and accuracy of identifying the model of the thermal dilution catheter are improved, and the possibility of operational errors by medical staff is reduced.

[0033] Embodiment 1:

[0034] Please refer to Figure 1 , Figure 1 4 is a flow chart of a method for identifying a thermal dilution catheter model provided in this embodiment.

[0035] Before describing the identification method, the thermodilution catheter is described. Figure 2 , 3 As shown, the thermal dilution catheter includes a first resistor R 常规1 , the second resistor R 常规2 , the third resistor R 热敏 , a first pin, a second pin, a third pin and a fourth pin, the first pin being connected to a first resistor.

[0036] R 常规1 One end and the third resistor R 热敏 One end of the first resistor R 常规1 The other end is connected to the third pin, the third resistor R 热敏 The other end is connected to the second resistor R 常规2 One end and the second pin, the second resistor R 常规2 The other end is connected to the fourth pin.

[0037] In practical applications, such as Figure 4 As shown, after connecting the second pin and the third pin, the first resistor R 常规1 and the third resistor R 热敏Form a parallel relationship with the second resistor R 常规2 At this time, the voltages at the second pin and the third pin are the same, which is the target voltage value U2.

[0038] It should be noted that the target voltage value U2 can be calculated by the following formula:

[0039]

[0040] Among them, U 14 is the voltage difference between the first pin and the fourth pin, R 常规1 is the resistance value of the first resistor, R 常规2 is the resistance value of the second resistor, R 热敏 is the resistance value of the third resistor.

[0041] In the embodiment of the present application, the first resistor and the second resistor include fixed resistors and / or adjustable resistors; the third resistor includes a thermistor.

[0042] In the embodiment of the present application, the resistance values ​​of the first resistor and the second resistor may be the same or different.

[0043] In practical applications, it is assumed that R 常规1 =10KΩ, R 常规2 =20KΩ, R 热敏 =10KΩ; Assuming R in thermodilution catheter model B 常规1 =20KΩ, R 常规2 =10KΩ, R 热敏 =10KΩ; where R of Model A and Model B 热敏 Same, at the same temperature R 热敏 Assume that the power supply voltage of the monitor is 1V, that is, U 14 The voltage is 1V, and according to the above formula, it can be calculated that the preset voltage value corresponding to model A is 0.2, and the preset voltage value corresponding to model B is 0.4. In this way, the corresponding relationship between the preset voltage value and the thermal dilution catheter model can be obtained.

[0044] like Figure 1 As shown, the identification method specifically includes the following steps S101-S105:

[0045] Step S101: connect the third pin to the second pin to connect the first resistor and the third resistor in parallel.

[0046] Step S102: supply power to the first pin and / or the fourth pin, so that a voltage difference is formed between the first pin and the fourth pin.

[0047] It should be noted that the voltage difference between the first pin and the fourth pin, namely, U14 It can be the power supply voltage of the monitor.

[0048] Step S103, obtaining resistance values ​​of the first resistor, the second resistor, and the third resistor.

[0049] It should be noted that the resistance values ​​of the first resistor and the second resistor are different in different thermodilution catheter models. For example, the resistance value of the first resistor in thermodilution catheter model A is different from the resistance value of the first resistor in thermodilution catheter model B; the resistance value of the second resistor in thermodilution catheter model A is different from the resistance value of the second resistor in thermodilution catheter model B.

[0050] Illustratively, the resistance value of the third resistor in the thermal dilution catheter model A may be the same as or different from the resistance value of the third resistor in the thermal dilution catheter model B.

[0051] In the embodiment of the present application, when obtaining the resistance value of the third resistor, the resistance value of the thermistor may be detected.

[0052] It should be noted that thermistors can include positive temperature coefficient thermistors and negative temperature coefficient thermistors. Among them, the resistance value of the positive temperature coefficient thermistor increases with the increase of temperature. The resistance value of the negative temperature coefficient thermistor decreases with the increase of temperature. The temperature coefficient range of common NTC thermistors is -2% to -6.5%, which can be widely used in temperature measurement, temperature compensation, surge current suppression and other occasions.

[0053] Step S104: Based on the resistance values ​​of the first resistor, the second resistor and the third resistor, and the voltage difference between the first pin and the fourth pin, a target voltage value of the first resistor and the third resistor in parallel is calculated.

[0054] In the embodiment of the present application, when calculating the target voltage value of the first resistor and the third resistor in parallel, the target voltage value can be calculated based on the above formula.

[0055] It should be noted that the target voltage value may represent a voltage value corresponding to the second pin, or may represent a voltage value corresponding to the third pin.

[0056] In the embodiment of the present application, the blood temperature at the femoral artery after thermal dilution can be obtained according to the resistance value of the thermistor. This is because the resistance value of the thermistor changes with the change of temperature. Therefore, when the blood temperature at the femoral artery changes after thermal dilution, the resistance value of the thermistor will also change accordingly. In this way, the corresponding blood temperature can be obtained according to the resistance value of the thermistor.

[0057] Step S105 : Identify the model of the thermodilution catheter based on the corresponding relationship between the target voltage value and the preset voltage value and the model of the thermodilution catheter.

[0058] In an embodiment of the present application, when identifying the model of the thermal dilution catheter, the target voltage value may be compared with a preset voltage value; when the target voltage value matches the preset voltage value, the thermal dilution catheter model corresponding to the matching preset voltage value is determined as the thermal dilution catheter model corresponding to the target voltage value.

[0059] It should be noted that the target voltage value matches the preset voltage value and can be the same as the preset voltage value. In this case, the thermodilution catheter model corresponding to the preset voltage value is also the thermodilution catheter model corresponding to the target voltage value. In this way, the model corresponding to the thermodilution catheter can be accurately identified.

[0060] The embodiment of the present application provides a method for identifying the model of a thermodilution catheter, which is applied to the thermodilution catheter, wherein the thermodilution catheter includes a first resistor, a second resistor, a third resistor, a first pin, a second pin, a third pin and a fourth pin, wherein the first pin is connected to one end of the first resistor and one end of the third resistor, the other end of the first resistor is connected to the third pin, the other end of the third resistor is connected to one end of the second resistor and the second pin, and the other end of the second resistor is connected to the fourth pin. The identification method includes: connecting the third pin to the second pin so that the first resistor and the third resistor are connected in parallel; supplying power to the first pin and / or the fourth pin so that a voltage difference is formed between the first pin and the fourth pin; obtaining the resistance values ​​of the first resistor, the second resistor and the third resistor; based on the resistance values ​​of the first resistor, the second resistor and the third resistor, and the voltage difference between the first pin and the fourth pin, calculating the target voltage value of the first resistor and the third resistor in parallel; and identifying the model of the thermodilution catheter based on the corresponding relationship between the target voltage value and the preset voltage value and the model of the thermodilution catheter. The present application connects the first resistor and the third resistor of the thermodilution catheter in parallel, and forms a voltage difference between the first pin and the fourth pin of the thermodilution catheter, thereby calculating the target voltage value of the first resistor and the third resistor in parallel based on the resistance values ​​of the first resistor, the second resistor, and the third resistor of the thermodilution catheter and the voltage difference between the first pin and the fourth pin, and confirms the model corresponding to the thermodilution catheter according to whether the target voltage value matches the preset voltage value. In this way, the efficiency and accuracy of identifying the thermodilution catheter model are improved, and the possibility of medical staff's operating errors is reduced.

[0061] Embodiment 2:

[0062] Please refer to Figure 5 , Figure 5 is a structural block diagram of a system for measuring hemodynamic parameters provided by this embodiment, such as Figure 5As shown, the system includes: a monitor 101 , a syringe 102 , an injection liquid temperature sensor 103 , a central venous pressure sensor 104 , an arterial pressure sensor 105 , a central venous catheter 106 and a thermal dilution catheter 107 .

[0063] In the embodiment of the present application, the injection liquid temperature sensor 103 is used to detect the temperature of the liquid output by the syringe 102 and output the detected temperature to the monitor 101 .

[0064] In the embodiment of the present application, the arterial pressure sensor 105 is used to detect the arterial blood pressure after the thermal dilution catheter 107 inputs liquid into the patient's body, and outputs the arterial blood pressure to the monitor 101.

[0065] In the embodiment of the present application, the central venous pressure sensor 104 is used to detect the central venous pressure after the central venous catheter 106 is inserted into the patient's body, and output the central venous pressure to the monitor 101.

[0066] It should be noted that the monitor 101 can autonomously identify the model of the thermal dilution catheter 107 .

[0067] In the embodiment of the present application, the monitor 101 is used to calculate hemodynamic parameters based on temperature, arterial blood pressure and central venous pressure.

[0068] It should be noted that the hemodynamic parameters include but are not limited to systolic blood pressure, diastolic blood pressure, heart rate, central venous pressure, stroke volume, cardiac output, cardiac output index, stroke volume index, stroke volume variation, global end-diastolic volume, global end-diastolic index, peripheral vascular resistance, peripheral vascular resistance index, global ejection fraction, and cardiac function index.

[0069] In the embodiment of the present application, the thermal dilution conduit 107 includes a first resistor R 常规1 , the second resistor R 常规2 , the third resistor R 热敏 , the first pin, the second pin, the third pin and the fourth pin, the first pin is connected to the first resistor R 常规1 One end and the third resistor R 热敏 One end of the first resistor R 常规1 The other end is connected to the third pin, the third resistor R 热敏 The other end is connected to the second resistor R 常规2 One end and the second pin, the second resistor R 常规2 The other end of the first resistor R 常规1 and the third resistor R 热敏 in parallel.

[0070] In the embodiment of the present application, the target voltage value of the first resistor and the third resistor in parallel can be calculated based on the resistance values ​​of the first resistor, the second resistor and the third resistor, and the voltage difference between the first pin and the fourth pin; then, based on the correspondence between the target voltage value and the preset voltage value and the model of the thermal dilution catheter, the model of the thermal dilution catheter can be identified.

[0071] In the embodiment of the present application, the first resistor and the second resistor include fixed resistors and / or adjustable resistors; the third resistor includes a thermistor.

[0072] In the embodiment of the present application, the resistance values ​​of the first resistor and the second resistor may be the same or different.

[0073] It should be noted that the resistance values ​​of the first resistor and the second resistor are different in different thermodilution catheter models. For example, the resistance value of the first resistor in thermodilution catheter model A is different from the resistance value of the first resistor in thermodilution catheter model B; the resistance value of the second resistor in thermodilution catheter model A is different from the resistance value of the second resistor in thermodilution catheter model B.

[0074] Illustratively, the resistance value of the third resistor in the thermal dilution catheter model A may be the same as or different from the resistance value of the third resistor in the thermal dilution catheter model B.

[0075] In practical applications, it is assumed that R 常规1 =10KΩ, R 常规2 =20KΩ, R 热敏 =10KΩ; Assuming R in thermodilution catheter model B 常规1 =20KΩ, R 常规2 =10KΩ, R 热敏 =10KΩ; where R of Model A and Model B 热敏 Same, at the same temperature R 热敏 Assume that the power supply voltage of the monitor is 1V, that is, U 14 The voltage is 1V, and according to the above formula, it can be calculated that the preset voltage value corresponding to model A is 0.2, and the preset voltage value corresponding to model B is 0.4. In this way, the corresponding relationship between the preset voltage value and the thermal dilution catheter model can be obtained.

[0076] It should be noted that thermistors can include positive temperature coefficient thermistors and negative temperature coefficient thermistors. Among them, the resistance value of the positive temperature coefficient thermistor increases with the increase of temperature. The resistance value of the negative temperature coefficient thermistor decreases with the increase of temperature. The temperature coefficient range of common NTC thermistors is -2% to -6.5%, which can be widely used in temperature measurement, temperature compensation, surge current suppression and other occasions.

[0077] In the embodiment of the present application, when calculating the target voltage value of the first resistor and the third resistor in parallel, the target voltage value can be calculated based on the above formula.

[0078] It should be noted that the target voltage value may represent a voltage value corresponding to the second pin, or may represent a voltage value corresponding to the third pin.

[0079] In the embodiment of the present application, the blood temperature at the femoral artery after thermal dilution can be obtained according to the resistance value of the thermistor. This is because the resistance value of the thermistor changes with the change of temperature. Therefore, when the blood temperature at the femoral artery changes after thermal dilution, the resistance value of the thermistor will also change accordingly. In this way, the corresponding blood temperature can be obtained according to the resistance value of the thermistor.

[0080] In an embodiment of the present application, when identifying the model of the thermal dilution catheter, the target voltage value may be compared with a preset voltage value; when the target voltage value matches the preset voltage value, the thermal dilution catheter model corresponding to the matching preset voltage value is determined as the thermal dilution catheter model corresponding to the target voltage value.

[0081] It should be noted that the target voltage value matches the preset voltage value and can be the same as the preset voltage value. In this case, the thermodilution catheter model corresponding to the preset voltage value is also the thermodilution catheter model corresponding to the target voltage value. In this way, the model corresponding to the thermodilution catheter can be accurately identified.

[0082] Exemplarily, the system for measuring hemodynamic parameters works as follows:

[0083] The medical staff draws 15 ml of iced saline with a temperature below 8°C through the syringe 102, and pushes the iced saline through the injection temperature sensor 103, and then through the central venous catheter 106 connected to the three-way valve, the iced saline reaches the patient's central vein, flows through the right atrium, right ventricle, lung, left atrium, left ventricle, and finally reaches the femoral artery. One end of the temperature interface cable is connected to the injection temperature sensor connection cable and the artery connection cable, and the other end is connected to the temperature port of the monitor 101. The monitor 101 measures the initial temperature of the iced saline and the blood temperature at the femoral artery after thermal dilution.

[0084] Thermodilution catheter 107 connects arterial pressure sensor 105 to the arterial pressure port of monitor 101, and is used to measure the systolic pressure, diastolic pressure, and heart rate of the patient; central venous catheter 106 connects central venous pressure sensor 104 to the central venous pressure port of monitor 101, and is used to measure central venous pressure. The system measures cardiac output using two modes, namely transpulmonary thermodilution method and pulse contour analysis method.

[0085] It should be noted that transpulmonary thermodilution is a technique used to measure cardiac index, preload and extravascular lung water in intensive care units. Specifically, transpulmonary thermodilution is based on the principle of thermodilution. A certain amount of ice saline (usually 15 ml, with a temperature below 8°C) is injected into the patient's vein. The injected ice saline passes through the right atrium, right ventricle, lungs, left atrium, left ventricle, and finally reaches the femoral artery. The cardiac output is calculated by measuring the temperature change of the liquid of known temperature and volume injected into the body in a certain period of time in the arterial blood.

[0086] It should be noted that pulse contour analysis is a method based on invasive measurement of peripheral arterial pulse waveforms to calculate cardiac output. Pulse contour analysis obtains information such as systolic pressure, diastolic pressure and mean arterial pressure by analyzing continuous arterial pressure signals. The area under the systolic pressure curve directly reflects the stroke volume (SV), that is, the amount of blood in milliliters discharged by the left ventricle during each heartbeat.

[0087] During thermodilution, the blood temperature changes relative to the baseline temperature of 37°C as follows: Figure 6 As shown by Figure 6 It can be seen that when the patient's central vein is injected with ice saline, the temperature change is not immediately measured in the femoral artery. Instead, after a period of time, the temperature rises and then falls. When the ice saline is diluted, the temperature returns to normal. From this, the area under the thermodilution curve can be obtained. In this way, the patient's cardiac output can be calculated using the Stewart Hamilton formula.

[0088] like Figure 7 As shown in the figure, the area under the curve of the femoral artery pulse pressure systolic pressure measured by the pressure end of the thermodilution catheter is the stroke volume. By multiplying the stroke volume by the heart rate, the continuous cardiac output can be obtained. An accurate calibration factor is required between the cardiac output measured by the pulse contour analysis method and the true cardiac output. The transpulmonary thermodilution method can be used as the calibration factor required by the pulse contour analysis method.

[0089] It should be noted that when injecting ice saline based on the transpulmonary thermodilution method, the injection process cannot be automatically timed. At this time, two medical staff are required to operate together, that is, one medical staff injects the ice saline and the other medical staff counts down. However, the result obtained in this way will have certain errors.

[0090] In the embodiments of the present application, Figure 8-10As shown, the injection liquid temperature sensor 20 includes a first shell 201 and a second shell 202; a magnet 203 and a spring 204 are sequentially arranged in the inner cavity of the first shell 201; the magnet 203 and the spring 204 are arranged in contact; the spring 204 is close to the second shell 202; the second shell 202 is fixedly connected to the first shell 201; a Hall sensor 205 is arranged on the outside of the injection liquid temperature sensor 20, and the Hall sensor 205 is used to sense the magnet 203.

[0091] It should be noted that the injection liquid temperature sensor 20 is used to automatically measure the temperature of the injection liquid.

[0092] It should be noted that the Hall sensor 205 is used to detect the position of the magnet 203. Specifically, when the magnet 203 is close to the Hall sensor 205, the magnetic field generated by it will change the movement direction of the charges inside the Hall sensor 205, thereby causing a change in the potential difference. By measuring this potential difference, the Hall sensor 205 can accurately obtain information such as the position and direction of the magnet 203.

[0093] It should be noted that the magnet 203 can be any type of magnet. For example, the magnet 203 can be a ferrite magnet; the distance between the injection temperature sensor 20 and the magnet 203 can be any value. For example, the distance between the injection temperature sensor 20 and the magnet 203 can be any value between 8 mm and 10 mm.

[0094] In the embodiment of the present application, when the syringe does not output liquid to the injection liquid temperature sensor, the Hall sensor senses the magnet, thereby outputting a first signal to the monitor; when the syringe outputs liquid to the injection liquid temperature sensor, the Hall sensor does not sense the magnet, thereby outputting a second signal to the monitor; the monitor records the duration of the second signal and uses the duration as the infusion duration of the syringe. In this way, the monitor can realize automatic timing of the ice saline injection process.

[0095] In actual applications, there are magnets and springs inside the injection liquid temperature sensor, and a Hall sensor inside the injection liquid temperature sensor cable. The injection liquid temperature sensor is connected to the injection liquid temperature sensor cable. When the injection liquid temperature sensor is in the closed state, the Hall sensor senses the magnet and outputs a "0" level to the outside; when the injection liquid temperature sensor is in the connected state, the magnet moves away from the Hall sensor due to the thrust of the liquid, and the Hall sensor outputs a "1" level to the outside. The matching monitor receives the signal from the Hall sensor and can obtain the time when the injection liquid temperature sensor is connected and closed according to the duration of the signal state.

[0096] An embodiment of the present application provides a system for measuring hemodynamic parameters, the system comprising: a monitor, a syringe, an injection liquid temperature sensor, a central venous pressure sensor, an arterial pressure sensor, a central venous catheter, and a thermal dilution catheter. The injection liquid temperature sensor is used to detect the temperature of the liquid output by the syringe, and output the detected temperature to the monitor. The arterial pressure sensor is used to detect the arterial blood pressure after the thermal dilution catheter inputs the liquid into the patient's body, and outputs the arterial blood pressure to the monitor. The central venous pressure sensor is used to detect the central venous pressure after the central venous catheter is inserted into the patient's body, and outputs the central venous pressure to the monitor. The monitor can autonomously identify the efficiency and accuracy of the thermal dilution catheter model, thereby reducing the possibility of operational errors by medical staff. At the same time, the monitor can also realize automatic timing of the ice saline injection process.

[0097] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the idea of ​​the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A method for identifying a thermodilution catheter model, applied to a thermodilution catheter, characterized in that: The thermal dilution catheter comprises a first resistor, a second resistor, a third resistor, a first pin, a second pin, a third pin and a fourth pin, wherein the first pin is connected to one end of the first resistor and one end of the third resistor, the other end of the first resistor is connected to the third pin, the other end of the third resistor is connected to one end of the second resistor and the second pin, and the other end of the second resistor is connected to the fourth pin; the identification method comprises: Connecting the third pin to the second pin so that the first resistor and the third resistor are connected in parallel; supplying power to the first pin and / or the fourth pin so that a voltage difference is formed between the first pin and the fourth pin; Obtaining resistance values ​​of the first resistor, the second resistor, and the third resistor; Based on the resistance values ​​of the first resistor, the second resistor and the third resistor, and the voltage difference between the first pin and the fourth pin, a target voltage value of the first resistor and the third resistor in parallel is calculated; Based on the correspondence between the target voltage value and the preset voltage value and the model of the thermal dilution catheter, the model of the thermal dilution catheter is identified.

2. The identification method according to claim 1, characterized in that: The first resistor and the second resistor include fixed resistors and / or adjustable resistors; The third resistor includes a thermistor.

3. The identification method according to claim 1, characterized in that: The step of calculating a target voltage value of the first resistor and the third resistor in parallel based on the resistance values ​​of the first resistor, the second resistor, and the third resistor, and the voltage difference between the first pin and the fourth pin, comprises: The target voltage value U2 is calculated based on the following formula: Among them, U 14 is the voltage difference between the first pin and the fourth pin, R 常规1 is the resistance value of the first resistor, R 常规2 is the resistance value of the second resistor, R 热敏 is the resistance value of the third resistor.

4. The identification method according to any one of claims 1 to 3, characterized in that: The resistance values ​​of the first resistor and the second resistor are the same or different.

5. The identification method according to claim 3, characterized in that: The identifying the model of the thermal dilution catheter based on the correspondence between the target voltage value and the preset voltage value and the thermal dilution catheter model includes: Comparing the target voltage value with the preset voltage value; In a case where the target voltage value matches the preset voltage value, the thermal dilution catheter model corresponding to the matched preset voltage value is determined as the thermal dilution catheter model corresponding to the target voltage value.

6. The method according to claim 2, characterized in that The obtaining the resistance value of the third resistor comprises: detecting the resistance value of the thermistor; The method further comprises: The temperature of the blood at the femoral artery after thermal dilution is obtained according to the resistance value of the thermistor.

7. A system for measuring hemodynamic parameters, characterized in that: The system comprises: Monitors, syringes, injection temperature sensors, central venous pressure sensors, arterial pressure sensors, central venous catheters, and thermodilution catheters; The injection liquid temperature sensor is used to detect the temperature of the liquid output by the syringe, and output the detected temperature to the monitor; The arterial pressure sensor is used to detect the arterial blood pressure after the thermodilution catheter inputs the liquid into the patient's body, and output the arterial blood pressure to the monitor; The central venous pressure sensor is used to detect the central venous pressure after the central venous catheter is inserted into the patient's body, and output the central venous pressure to the monitor; The monitor is used to calculate hemodynamic parameters based on the temperature, the arterial blood pressure and the central venous pressure.

8. The system according to claim 7, characterized in that The thermal dilution catheter comprises a first resistor, a second resistor, a third resistor, a first pin, a second pin, a third pin and a fourth pin, wherein the first pin is connected to one end of the first resistor and one end of the third resistor, the other end of the first resistor is connected to the third pin, the other end of the third resistor is connected to one end of the second resistor and the second pin, and the other end of the second resistor is connected to the fourth pin; After the third pin is connected to the second pin, the first resistor and the third resistor are connected in parallel.

9. The system according to claim 7, characterized in that The injection liquid temperature sensor comprises a first housing and a second housing; The inner cavity of the first shell is provided with a magnet and a spring in sequence; the magnet and the spring are arranged in contact; the spring is close to the first shell; the second shell is fixedly connected to the first shell; A Hall sensor is arranged outside the injection liquid temperature sensor, and the Hall sensor is used for sensing the magnet.

10. The system according to claim 9, characterized in that When the syringe does not output liquid to the injection liquid temperature sensor, the Hall sensor senses the magnet, thereby outputting a first signal to the monitor; when the syringe outputs liquid to the injection liquid temperature sensor, the Hall sensor does not sense the magnet, thereby outputting a second signal to the monitor; The monitor records the duration of the second signal and uses the duration as the infusion duration of the syringe.

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