A blood-heating ECMO circulation kit and its control method

Abstract

The present invention relates to the field of ECMO technology and provides a blood-heating ECMO circulation kit and a control method thereof. The kit comprises a first blood delivery tube, a blood pump, a second blood delivery tube, a membrane lung oxygenator, a third blood delivery tube, and a human body cannula, which are sequentially connected to form a blood circulation loop; the electrothermal conductive coatings and / or metal wires at the head and tail ends of the first blood delivery tube, the second blood delivery tube, and the third blood delivery tube are all connected to sensors via sensor connectors; the electrothermal conductive coatings and / or metal wires of the first blood delivery tube, the second blood delivery tube, and the third blood delivery tube are connected together and connected to an intelligent heating controller and a plurality of terminators; the intelligent heating controller outputs three-level voltages, and realizes heating, charging, and data acquisition functions through different voltage controls, which is beneficial for observing thrombi and gas emboli in the blood circuit.

Description

Technical Field

[0001] The present invention relates to the field of ECMO technology, and in particular to a blood-heating ECMO circulation bag and a control method thereof. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] Extracorporeal membrane oxygenation (ECMO) is an important technology for providing life support to critically ill patients who have lost their cardiopulmonary function.

[0004] The extracorporeal circulation pipelines of existing ECMO dissipate heat quickly and have poor thermal insulation effect, resulting in the temperature of the blood input into the human body being lower than the body temperature, causing the patient to suffer from hypothermia, especially when the extracorporeal circulation supports ECMO for a long time.

[0005] Currently, there are two main methods to achieve blood heating:

[0006] (1) Hot water jacket heating: A constant temperature hot water machine is required, and the water jacket makes the pipe diameter thicker, which is not convenient for surgical implementation; and the water jacket is integrated with the blood transfusion tube, which makes it difficult to operate during blood handling. For example, temporary hemostasis only requires clamping the blood transfusion tube with hemostatic forceps, but this solution is obviously more difficult;

[0007] (2) Electric heating solution: Its disadvantage is that it requires many layers and has a complex structure. Summary of the Invention

[0008] In order to address the deficiencies of the prior art, the present invention provides a blood-heating ECMO circulation bag and a control method thereof. Through the three-level voltage control of the intelligent heating controller, it is only necessary to set two mutually insulated, transparent or translucent electrothermal conductive coatings between the inner insulating layer and the outer insulating layer, or a mutually insulated, transparent or translucent electrothermal conductive coating and a metal wire, to realize the blood heating function, sensor charging function, data acquisition and transmission function, which greatly simplifies the blood delivery tube structure and is conducive to the observation of thrombus and air embolism in the blood pipeline.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A first aspect of the present invention provides a blood-heating ECMO circulation kit.

[0011] A blood-heating ECMO circulation kit includes a first blood delivery tube, a blood pump, a second blood delivery tube, a membrane lung oxygenator, a third blood delivery tube, and a human cannula connected in sequence to form a blood circulation loop;

[0012] The first, second, and third blood delivery tubes each include an inner insulating layer and an outer insulating layer; two mutually insulated, transparent or translucent electrothermal conductive coatings are disposed between the inner and outer insulating layers, or a mutually insulated, transparent or translucent electrothermal conductive coating and a metal conductor are disposed between the inner and outer insulating layers; the electrothermal conductive coatings and / or metal conductors at the head and tail ends of the first, second, and third blood delivery tubes are connected to sensors via sensor connectors; the electrothermal conductive coatings and / or metal conductors of the first, second, and third blood delivery tubes are connected together and connected to an intelligent heating controller and several terminators. The intelligent heating controller outputs three levels of voltage: the first level of voltage drives the relay in the terminator to close, forming a closed circuit and causing the electrothermal conductive coating to generate heat; at the second level of voltage, the sensor switches to charging mode; and at the third level of voltage, the sensor performs data acquisition and communicates with the intelligent heating controller.

[0013] Furthermore, the two electroheating conductive coatings are two C-shaped electroheating conductive coatings arranged opposite to each other.

[0014] Furthermore, the two electrothermal conductive coatings are two sleeved tubular electrothermal conductive coatings, and a middle insulating layer is provided between the two tubular electrothermal conductive coatings.

[0015] Furthermore, the electroheating conductive coating is tubular, and the metal wire is arranged in the outer insulating layer.

[0016] Furthermore, the three-level voltage has different values ​​at different ambient temperatures.

[0017] Furthermore, a first temperature sensor is provided at the head end of the first blood delivery tube; a second temperature sensor and a first pressure sensor are provided at the tail end of the first blood delivery tube; a second pressure sensor is provided at the head end of the second blood delivery tube; a third temperature sensor is provided at the tail end of the second blood delivery tube; a fourth temperature sensor and a third pressure sensor are provided at the head end of the third blood delivery tube; and a fifth temperature sensor is provided at the tail end of the third blood delivery tube.

[0018] Furthermore, the intelligent heating controller includes an electronic switch, a microprocessor, an RS485 communication unit, a current monitoring unit, a constant voltage power supply unit and a voltage control unit; the electronic switch is connected to the sensor connector through two wires, and is respectively connected to the constant voltage power supply unit and the RS485 communication unit through two wires; the microprocessor is connected to the voltage control unit, the current monitoring unit, the electronic switch and the RS485 communication unit, and the voltage control unit is connected to the constant voltage power supply unit, one end of the current monitoring unit is connected to the connection line between the constant voltage power supply unit and the electronic switch, and the other end is connected to the microprocessor.

[0019] Furthermore, the sensor connector includes a single-chip microcomputer system, an energy storage capacitor, a voltage-stabilized power supply, a voltage monitoring unit, an electronic switch and an RS485 interface; the electronic switch is connected to the electrothermal conductive coating and / or the metal wire through two wires, and is respectively connected to the voltage-stabilized power supply and the RS485 interface through two wires, the single-chip microcomputer system is respectively connected to the energy storage capacitor, the sensor probe and the RS485 interface, and the voltage monitoring unit is connected to the electronic switch and the connection line between the electronic switch and the voltage-stabilized power supply.

[0020] Furthermore, the terminator includes a voltage monitoring unit, a delay switch circuit, a relay and a delay switch circuit; a wire is connected to each end of the delay switch circuit, the relay and the voltage monitoring unit, and both wires at the two ends are connected to the electroheating conductive coating and / or the metal wire; the capacitor is connected to the delay switch circuit, and the voltage monitoring unit, the delay switch circuit and the relay are connected in sequence.

[0021] A second aspect of the present invention provides a method for controlling a blood-heating ECMO circulation bag.

[0022] A method for controlling a blood-heating ECMO circulation kit according to the first aspect comprises the following steps:

[0023] The intelligent heating controller outputs the first-level voltage, the relay in the terminator is closed, forming a closed loop, and the electrothermal conductive coating generates heat;

[0024] The intelligent heating controller outputs the second level voltage and the sensor switches to charging mode;

[0025] The intelligent heating controller outputs a third-level voltage, and the sensor collects data and communicates with the intelligent heating controller.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The blood-heating ECMO circulation kit described in the present invention is controlled by the three-level voltage of the intelligent heating controller. It only needs to set two mutually insulated, transparent or translucent electrothermal conductive coatings between the inner insulating layer and the outer insulating layer, or a mutually insulated, transparent or translucent electrothermal conductive coating and a metal wire to achieve blood heating function, sensor charging function, data acquisition and transmission function, which greatly simplifies the structure of the blood delivery tube and is conducive to the observation of thrombus and gas embolism in the blood pipeline.

[0028] The blood-heating ECMO circulation kit described in the present invention has multiple temperature sensors and pressure sensors installed at different positions of the first blood delivery tube and the second blood delivery tube, which can comprehensively monitor the blood temperature and pressure at different positions such as the blood pump outlet, the membrane oxygenator inlet and outlet, and the head end of the human cannula.

[0029] The blood-heating ECMO circulation kit described in the present invention has three levels of voltage with different values ​​at different ambient temperatures. The heating power can be flexibly adjusted according to the actual environment to adapt to different working conditions and ensure the stability of blood temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0031] Figure 1 This is an overall structural diagram of a blood-heating ECMO circulation kit provided by an embodiment of the present invention;

[0032] Figure 2 A first structural diagram of a blood delivery tube provided by an embodiment of the present invention;

[0033] Figure 3 A second structural diagram of a blood delivery tube provided in an embodiment of the present invention;

[0034] Figure 4 A third structural diagram of a blood delivery tube provided in an embodiment of the present invention;

[0035] Figure 5 This is a diagram showing the overall structure of a blood heating ECMO circulation kit with an oxygenator water circulation heater provided in an embodiment of the present invention;

[0036] Figure 6 A diagram showing the internal structure of an oxygenator water circulation heater provided in an embodiment of the present invention;

[0037] Figure 7 A first circuit diagram of a blood-heating ECMO circulation kit provided in an embodiment of the present invention;

[0038] Figure 8 A second circuit diagram of a blood-heating ECMO circulation kit provided in an embodiment of the present invention;

[0039] Figure 9 A circuit diagram of an intelligent heating controller provided in an embodiment of the present invention;

[0040] Figure 10 A circuit diagram of a temperature sensor connector provided by an embodiment of the present invention;

[0041] Figure 11 A circuit diagram of a blood oxygen sensor connector provided by an embodiment of the present invention;

[0042] Figure 12 A circuit diagram of a pressure sensor connector provided by an embodiment of the present invention;

[0043] Figure 13 A circuit diagram of a universal sensor connector provided by an embodiment of the present invention;

[0044] Figure 14 A circuit diagram of a multi-sensor connector provided by an embodiment of the present invention;

[0045] Figure 15 A circuit diagram of a terminator provided in an embodiment of the present invention;

[0046] Figure 16 A schematic diagram of a thermal insulation cover provided in an embodiment of the present invention;

[0047] Figure 17 A flow chart of a control method for a blood-heating ECMO circulation kit provided in an embodiment of the present invention;

[0048] Figure 18 This is a flow chart of a method for formulating heating parameters provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0050] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention, and should not be understood as limiting the present invention.

[0053] In the present invention, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in the present invention based on specific circumstances, and they should not be construed as limitations of the present invention.

[0054] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0055] Example 1

[0056] Embodiment 1 of the present invention provides a blood-heating ECMO circulation kit.

[0057] In this embodiment, the head end and the tail end are defined according to the direction of blood flow. The head end of a section of pipeline refers to the head end of the blood flow direction in the section of pipeline.

[0058] A blood-heating ECMO circulation kit provided in Example 1 of the present invention includes a first blood delivery tube 1, a second blood delivery tube 2, a third blood delivery tube 3, a human cannula 4, a medical plug 5, a blood pump 6, a membrane lung oxygenator 15, several temperature sensors, several pressure sensors, an intelligent heating controller and a terminal.

[0059] like Figure 1 As shown, a first blood delivery tube 1, a blood pump 6, a second blood delivery tube 2, a membrane oxygenator 15, a third blood delivery tube 3, and a human cannula 4 are sequentially connected to form a blood circulation loop. Specifically, the first blood delivery tube 1, the second blood delivery tube 2, the third blood delivery tube 3, and the human cannula 4 constitute a blood circuit.

[0060] The blood circulation loop is wrapped with an insulation cover, which can withstand low-temperature environments such as outdoor transportation. The insulation material can be insulation sponge or aerogel material to achieve better insulation effect.

[0061] As an embodiment, the insulation cover is prefabricated according to the shape of each component and provided with hook and loop fasteners, such as Figure 16 shown.

[0062] As a first implementation method, Figure 2 As shown, the first blood delivery tube 1, the second blood delivery tube 2, and the third blood delivery tube 3 each comprise three layers, from inside to outside: an inner insulating layer 7, an intermediate electrothermal conductive coating 8, and an outer insulating layer 9. The intermediate electrothermal conductive coating 8 comprises two C-shaped, mutually insulated, transparent or translucent electrothermal conductive coatings.

[0063] As a second implementation method, Figure 3 As shown, the first blood delivery tube 1, the second blood delivery tube 2, and the third blood delivery tube 3 each comprise four layers, from inside to outside: an inner insulating layer 7, an inner electroheating conductive coating 10, a middle insulating layer 11, an outer electroheating conductive coating 12, and an outer insulating layer 9. The inner electroheating conductive coating 10 and the outer electroheating conductive coating 12 are both tubular, transparent or translucent electroheating conductive coatings.

[0064] As a third embodiment, Figure 4 As shown, the first blood delivery tube 1, the second blood delivery tube 2, and the third blood delivery tube 3 each comprise three layers: from inside to outside: an inner insulating layer 7, an intermediate electrothermal conductive coating 8, and an outer insulating layer 9. The intermediate electrothermal conductive coating 8 is a tubular, transparent or translucent electrothermal conductive coating; an extremely thin, flat metal wire 16 is embedded within the outer insulating layer 9.

[0065] The inner insulating layer 7 , the middle insulating layer 11 and the outer insulating layer 9 are all transparent or semi-transparent.

[0066] Among them, the electrothermal conductive coating uses a conductive polymer such as PEDOT:PSS or a graphene film layer.

[0067] The channel inside the inner insulating layer 7 is a blood channel.

[0068] like Figure 1 As shown, the electroheating conductive coating and / or metal wire 16 between the first blood delivery tube 1 and the second blood delivery tube 2 is connected via a cross-blood pump bridge jumper. The electroheating conductive coating and / or metal wire 16 between the second blood delivery tube 2 and the third blood delivery tube 3 is connected via a cross-oxygenator bridge jumper.

[0069] like Figure 1 As shown, the first end and the tail end of the first blood delivery tube 1 , the second blood delivery tube 2 and the third blood delivery tube 3 are all provided with sensor connectors 13 .

[0070] Preferably, there are five temperature sensors and three pressure sensors.

[0071] Specifically, the first temperature sensor is connected to the sensor connector 13 at the head end of the first blood delivery tube 1, and is used to detect the blood temperature at the blood outlet; the second temperature sensor is connected to the sensor connector 13 at the tail end of the first blood delivery tube 1, and is used to detect the blood temperature before the pump; the third temperature sensor is connected to the sensor connector 13 at the tail end of the second blood delivery tube 2, and is used to detect the blood temperature before the membrane lung; the fourth temperature sensor is connected to the sensor connector 13 at the head end of the third blood delivery tube 3, and is used to detect the blood temperature after the membrane lung; the fifth temperature sensor is connected to the sensor connector 13 at the tail end of the third blood delivery tube 3, and is used to detect the blood temperature at the blood inlet.

[0072] Specifically, the first pressure sensor is connected to the sensor connector 13 at the tail end of the first blood delivery tube 1 for detecting the blood pressure before the pump; the second pressure sensor is connected to the sensor connector 13 at the head end or tail end of the second blood delivery tube 2 for detecting the blood pressure after the pump (i.e., before the membrane lung); the third pressure sensor is connected to the sensor connector 13 at the head end of the third blood delivery tube 3 for detecting the blood pressure after the membrane lung.

[0073] As an embodiment, the sensor connector 13 at the tail end of the second blood delivery tube 2 is also connected to a blood oxygen sensor for detecting blood oxygen before the membrane lung; the sensor connector 13 at the head end of the third blood delivery tube 3 is also connected to a blood oxygen sensor for detecting blood oxygen after the membrane lung.

[0074] In addition, as needed, the sensor connectors 13 at the head and tail ends of the first blood delivery tube 1 , the second blood delivery tube 2 , and the third blood delivery tube 3 may also be connected to other sensors.

[0075] like Figure 2 and Figure 3 As shown, the sensor connector 13 is electrically connected to the electroheating conductive coating and / or the metal wire 16 via a conductive patch 14. Specifically, a conductive patch is fixedly mounted on one C-shaped electroheating conductive coating or the inner electroheating conductive coating, and is connected to the sensor connector 13 via a wire. A conductive patch is also fixedly mounted on the other C-shaped electroheating conductive coating or the outer electroheating conductive coating or the metal wire 16, and is connected to the sensor connector 13 via a wire.

[0076] In this embodiment, if Figure 5As shown, the membrane oxygenator 15 has an independent oxygenator water circulation heater.

[0077] As a first implementation method, Figure 7 As shown, the oxygenator water circulation heater has an independent electrical socket for power supply, and a medical plug 5 is provided at the head end of the first blood delivery tube 1, the medical plug 5 is connected to the pipeline electrical socket on the intelligent heating controller, and the terminator is provided at the tail end of the third blood delivery tube 3 to form an electrical circuit.

[0078] As a second implementation method, Figure 8 As shown, the pipeline electrical socket and the oxygenator electrical socket are combined into one, and the intelligent heating controller is connected to the oxygenator water circulation heater and the blood delivery tube via a main cable. Specifically, the intelligent heating controller is provided with a pipeline electrical socket and an oxygenator electrical socket. The pipeline electrical socket is connected to the cross-oxygenator bridge jumper via the main cable, and the oxygenator electrical socket is connected to the oxygenator water circulation heater via the main cable. At the same time, a terminator is provided at the head end of the first blood delivery tube 1 and the tail end of the third blood delivery tube 3, forming two electrical circuits.

[0079] like Figure 6 As shown, the oxygenator water circulation heater comprises an oxygenator heat exchanger, a circulating water pump, and an electric heating tube connected in sequence, forming a circulating water loop. The electric heating tube heats the circulating water through electrothermal heating, similar to an electric kettle. By using the circulating water as a heat transfer medium, the temperature rise of the oxygenator heat exchanger within the membrane oxygenator 15 is relatively gradual, without changing the existing physical structure of the membrane oxygenator 15.

[0080] The flow rate of the circulating water is 10 L / min. For different models of membrane oxygenators 15 , the flow rate may deviate due to differences in water flow resistance of the heat exchanger.

[0081] The oxygenator's water circulation heater is equipped with three temperature sensors: a temperature sensor in the middle of the electric heating tube, measuring value T1; a temperature sensor at the water outlet, measuring value T2 (hot water outlet temperature, equivalent to blood outlet temperature); and a temperature sensor at the water inlet, measuring value T3. To accurately measure water temperature, a temperature sensor with a measurement range of 0 to 50 degrees Celsius and an accuracy of at least 0.3 degrees Celsius is required. Decisions and actions are made based on the values ​​of these three sensors, as shown in Table 1.

[0082] Table 1. Judgment and processing based on the values ​​of three sensors

[0083]

[0084] Among them, the maximum heating power of the oxygenator water circulation heater is 200W, and the heating controller uses constant voltage PWM modulation to control the heating power.

[0085] The heating power of the oxygenator water circulation heater is related to the blood flow rate, and its derivation formula is:

[0086] (1) Constants:

[0087] The flow rate of the heat medium (circulating water) is 10 liters / minute and the density is about 1000 kg / m 3 , so the heat medium mass flow rate is 10kg / min or 0.167kg / s;

[0088] The specific heat capacity of the heat medium takes the standard value ch=4200J / (kg·℃);

[0089] The blood flow rate is L liters / minute, and the density is close to that of water, so the blood mass flow rate is L×0.0167 kg / s;

[0090] The specific heat capacity of blood is cb = 3550 J / (kg·℃);

[0091] The blood flow rate is generally 0.5 to 8 L / min, which is lower than the heat medium flow rate. Generally speaking, the heat exchanger efficiency loss of the oxygenator can be considered negligible.

[0092] (2) Analysis:

[0093] The system is in steady state, and the electric heating power P is completely used to compensate for the heat transferred to the blood by the heat medium through the heat exchanger, and other heat losses are ignored; the temperature sensor measures the temperature of the heat medium before and after the heat exchanger, T2 is the temperature of the heat medium when it enters the heat exchanger, and T3 is the temperature of the heat medium when it leaves the heat exchanger.

[0094] (3) Calculation:

[0095] Based on the law of conservation of energy, the electric heating power P is equal to the heat absorbed by the blood and also equal to the heat released by the heat medium:

[0096] P = cb × L × 0.0167 × blood temperature rise = ch × 0.167 × heat medium temperature drop;

[0097] Right now:

[0098] P = 3550 × L × 0.0167 × blood temperature rise = 4200 × 0.167 × (T3–T2);

[0099] Where: P: electric heating power, unit W; L: blood flow, unit liter / minute; T3-T2: temperature drop of heat medium, unit °C;

[0100] The above formula can be rearranged to: P = 4200 × 0.167 × (T3 – T2); that is, after 1 to 2 seconds of operation, the heating power can be calculated by the temperature difference between T3 and T2.

[0101] If the temperature fluctuations are large, a disc filter or a Kalman filter can be used to smooth them.

[0102] Generally speaking, since the blood flow rate is lower than the heat medium flow rate and the heat medium pipelines of the heat exchanger of the oxygenator are dense, it can be considered that the heat exchange is sufficient and the blood outlet temperature is equal to the heat medium outlet temperature, that is, Tblood_out=T3.

[0103] According to the above formula: 3550×L×0.0167×(Tblood_out-Tblood_in)=4200×0.167×(T3–T2); since L is known (the flow parameter is obtained from the ECMO host), the temperature of the blood entering the oxygenator can be deduced as: Tblood_in=T3–11.83×(T3–T2) / L. This temperature can also be compared with the value of the temperature sensor on the blood delivery pipeline to detect potential failures or malfunctions.

[0104] In this embodiment, all temperature sensors, pressure sensors, blood oxygen sensors and other sensors are collectively referred to as sensors.

[0105] like Figure 9 As shown, the intelligent heating controller includes: an electronic switch, a microprocessor, an RS485 communication unit, a current monitoring unit, a constant voltage power supply unit, a voltage control unit, a main power supply, and a regulated power supply. The electronic switch is connected to the pipeline electrical socket via two wires, and is also connected to the constant voltage power supply unit and the RS485 communication unit via two wires respectively; the microprocessor is connected to the voltage control unit, the current monitoring unit, the electronic switch, and the RS485 communication unit, and the voltage control unit is connected to the constant voltage power supply unit. One end of the current monitoring unit is connected to the connection line between the constant voltage power supply unit and the electronic switch, and the other end is connected to the microprocessor; the main power supply is connected to the constant voltage power supply unit and the regulated power supply respectively; the regulated power supply and the microprocessor are connected to the oxygenator electrical socket.

[0106] The intelligent heating controller obtains data from all sensors (including the temperature values ​​of five temperature sensors and the pressure values ​​of three pressure sensors) through time-sharing multiplexing communication. The entire circuit is connected to the intelligent heating controller with only one two-wire plug.

[0107] Microprocessor: As the core component, it analyzes and determines based on the set logic, and then issues control instructions. Voltage Control Unit and Constant Voltage Power Supply Unit: The voltage control unit works with the constant voltage power supply unit to ensure stable power supply and provide appropriate voltage for the normal operation of each component. Current Monitoring Unit: Monitors the circuit current in real time and provides feedback to the microprocessor. Electronic Switch: Controlled by the microprocessor, it switches the circuit on and off. RS485 Communication Unit: Enables communication between the intelligent heating controller and external devices (sensors), facilitating remote monitoring and data transmission.

[0108] Among them, RS485 is a differential signal half-duplex communication mode, and the voltage difference between the two signal lines is 5V.

[0109] The control logic of the intelligent heating controller is: if the electroheating conductive coating is to be driven to generate heat, the microprocessor controls the constant voltage power supply unit through the voltage control unit to output a voltage of more than 7V (generally 7-36V); if the sensor is to be charged, the microprocessor controls the constant voltage power supply unit through the voltage control unit to output a voltage higher than 6V but lower than 7V, so that the electroheating conductive coating will not form a loop; if RS485 communication is to be performed, the microprocessor controls the constant voltage power supply unit through the voltage control unit to output a voltage lower than 6V (e.g., 5V), so that the electroheating conductive coating will not form a closed-loop current.

[0110] The sensor connector 13 may be a temperature sensor connector, a blood oxygen sensor connector, a pressure sensor connector, a universal sensor connector, or a multi-sensor connector. Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 and Figure 14 As shown, the internal structure of the sensor connector 13 is the same, but the connected sensors (probes) are different, so the names are different.

[0111] like Figure 10 As shown, the sensor connector 13 includes a DC / DC, a single-chip microcomputer system, an energy storage capacitor, a voltage-stabilized power supply, a voltage monitoring unit, an electronic switch, and an RS485 interface. The electronic switch is electrically connected to the electroheating conductive coating and / or metal wire 16 via two wires in the form of a conductive patch 14. It is also connected to the voltage-stabilized power supply and the RS485 interface via two wires. The single-chip microcomputer system is connected to the energy storage capacitor, the probe, and the RS485 interface respectively. The voltage monitoring unit is connected to the electronic switch and the connection line between the electronic switch and the voltage-stabilized power supply. The energy storage capacitor is connected to the probe via the DC / DC to provide external power.

[0112] For the temperature sensor connector, the temperature probe of the connected probe is replaced; for the pressure sensor connector, the probe is replaced with a liquid pressure sensor, which is set in the manifold of the blood pipeline; for the blood oxygen sensor connector, the probe is replaced with a blood oxygen probe and an optical window; the universal sensor connector is similar to it, except that the probe is replaced with other sensors; for the multi-sensor connector, there are multiple probes.

[0113] The control logic of the sensor is: when the voltage monitoring unit detects that the voltage on the two wires is higher than 6V, the electronic switch switches to charging mode, and the voltage on the two wires is reduced to 5V through a voltage-stabilized power supply to avoid damaging the internal circuit of the sensor, and to charge the energy storage capacitor; when the voltage on the two wires is lower than 6V, the electronic switch switches to the RS485 interface. At this time, the power in the energy storage capacitor can maintain the operation of the microcontroller for about 0.5 seconds. The microcontroller system must complete temperature or pressure acquisition and communication within 0.5 seconds.

[0114] Since the microcontroller executes instructions in nanoseconds, the slowest bottleneck is the RS485 communication. If a baud rate of 9600 is used, under normal circumstances, the task of uploading temperature or pressure signals (data packets usually do not exceed 10 bytes; if the data volume is larger, the baud rate can be increased) should be completed within 0.01 seconds.

[0115] The terminator does not use a single chip microcomputer, but is composed of a voltage comparator and a NE555 time base circuit. Figure 15 As shown, the terminator includes a voltage monitoring unit, a time-delay switch circuit, a relay, and the time-delay switch circuit. A wire is connected to each end of the time-delay switch circuit, the relay, and the voltage monitoring unit. Both wires at the ends are connected to the electroheating conductive coating and / or metal wire. A capacitor is connected to the time-delay switch circuit. The voltage monitoring unit, the time-delay switch circuit, and the relay are also connected in sequence.

[0116] The control logic of the terminal is as follows: when a voltage greater than 7V appears on the two pins (i.e., the two wires of sensor connector 13), the delay switch is activated (the delay time is controlled by a capacitor), causing the relay to close. The relay short-circuit the two pins, forming a closed circuit between the intelligent heating controller and the electrothermal conductive coating, which generates heat, forming a heating closed loop. Approximately 2 seconds after the relay is closed, the delay switch circuit expires, the relay opens, and the open circuit state is restored. In this open circuit state, the intelligent heating controller can detect when the loop current has returned to zero. It can then use the two open electrothermal conductive coatings (equivalent to wires) to communicate with the three fully charged pressure sensors and four temperature sensors via RS485, obtaining their pressure and temperature information.

[0117] Since signals like pressure and temperature are simple numerical values, the communication burden is minimal, allowing communication tasks to be completed before the sensor capacitor is depleted. If you plan to add more sensors, you can also use a batch reading method. After reading two or three sensors, you can re-enter the charging process to replenish the sensor capacitor before reading the values ​​of the next batch of sensors.

[0118] The blood-heating ECMO circulation kit provided in this embodiment does not affect the observation of thrombus and gas embolism and does not change the existing surgical operation method.

[0119] The present embodiment provides a blood-heating ECMO circulation bag, which adopts a design in which the insulation cover is separated from the blood transfusion tube. The insulation cover has a simple design and is easy to operate. It can be quickly wrapped for insulation in extremely low temperature environments to ensure that the blood does not coagulate.

[0120] This embodiment provides a blood-heating ECMO circulation kit with an intelligent heating controller that can adopt different heating parameters based on pre-calculated sensor parameter curves and in combination with different usage scenarios.

[0121] Example 2

[0122] This embodiment provides a control method for a blood-heating ECMO circulation kit as described in Example 1.

[0123] This embodiment provides a control method for a blood heating ECMO circulation kit as described in Example 1, such as Figure 17 As shown, specifically including:

[0124] The microprocessor in the intelligent heating controller controls the constant voltage power supply unit to output a voltage of 7V or higher through the voltage control unit. When a voltage higher than 7V appears on the two pins of the terminal, the delay switch is triggered (the delay time is controlled by the capacitor), and the relay is turned on. The relay short-circuits the two pins, forming a closed loop between the intelligent heating controller and the electrothermal conductive coating, causing the electrothermal conductive coating (heating element) to heat up. At the same time, the intelligent heating controller is supplied with a constant voltage, and the current monitoring unit in the intelligent heating controller continuously monitors the current.

[0125] The time base circuit is started and the timing is 2 seconds. When the timing is up, the relay is disconnected and the open circuit state is restored. The intelligent heating controller detects that the loop current has returned to zero, switches the mode, and enters the process of communicating with the sensor. The communication voltage is lower than 6V, that is, the microprocessor controls the output voltage of the constant voltage power supply unit to be lower than 6V (e.g., 5V) through the voltage control unit, which will not trigger the terminal to work. At this time, after the voltage monitoring unit of the sensor detects that the voltage on the two wires is lower than 6V, the electronic switch switches to the RS485 interface. At this time, the power in the energy storage capacitor can maintain the operation of the single-chip microcomputer for about 0.5 seconds. The single-chip microcomputer system must complete the temperature or pressure acquisition and communication work within 0.5 seconds, and communicate with the intelligent heating controller via RS485. The intelligent heating controller collects all sensor values ​​in RS485 mode.

[0126] If the sensor is charged, the microprocessor controls the constant voltage power supply unit through the voltage control unit to output a voltage higher than 6V and lower than 7V, so that the electrothermal conductive coating will not form a circuit; at this time, when the voltage monitoring unit of the sensor detects that the voltage on the two wires is higher than 6V, the electronic switch switches to charging mode, and the voltage on the two wires is reduced to 5V through the voltage-stabilized power supply, and the energy storage capacitor is charged.

[0127] In this embodiment, the heating parameters (voltage) are formulated as follows: experiments are conducted in a laboratory using a substitute for blood (physiological saline, or a liquid with a specific heat capacity equal to that of blood), different ambient temperatures and flow rates are set, and different voltages are used to supply power in order to maximize the temperature of the fifth temperature sensor's proximity to the temperature of the first temperature sensor, while ensuring that the temperatures of the second temperature sensor, the third temperature sensor, and the fourth temperature sensor do not exceed 38° C. under any circumstances.

[0128] In the laboratory, water was used instead of blood to conduct experiments. Different ambient temperatures and flow rates were set. Different power supply voltages were used to make the temperature of the fifth temperature sensor as close as possible to that of the first temperature sensor. It was also ensured that the temperatures of the second temperature sensor, the third temperature sensor, and the fourth temperature sensor would not exceed 38°C under any circumstances.

[0129] Because blood has a lower specific heat capacity than water (3550 J / kg·°C vs. 4220 J / kg·°C), when heated using the same parameters, blood heats up faster than water. To maintain a constant temperature rise, the blood flow rate should be greater than the water flow rate. The calculation process is as follows:

[0130] Blood density (ρ-blood) × blood flow (Q-blood) × blood specific heat (C-blood) × ΔT = ρ-water × Q-water × C-water × ΔT;

[0131] Among them, ρ-blood is 1050g / cm 3 , C-blood is 3550 J / kg·℃, ρ-water is 1000 g / cm 3 , C-water is 4200J J / kg·℃.

[0132] The above formula can be simplified to:

[0133] Blood flow (Q-blood) = water flow (Q-water) × 1.127.

[0134] Specifically, if Figure 18 As shown, the test table shown in Table 2 is stored in the intelligent heating controller. The intelligent heating controller collects the ambient temperature and the temperature of each temperature sensor, uses fuzzy mathematics methods to generate a fuzzy membership function (triangle membership function), calculates the most appropriate power supply voltage parameters, and prompts the user whether to install the insulation cover.

[0135] Table 2, test table

[0136]

[0137] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A blood-heating ECMO circulation kit, characterized by: A blood circulation loop is formed by sequentially connecting a first blood delivery tube, a blood pump, a second blood delivery tube, a membrane lung oxygenator, a third blood delivery tube and a human body cannula; The first, second, and third blood delivery tubes each include an inner insulating layer and an outer insulating layer; two mutually insulated, transparent or translucent electrothermal conductive coatings are disposed between the inner and outer insulating layers, or a mutually insulated, transparent or translucent electrothermal conductive coating and a metal conductor are disposed between the inner and outer insulating layers; the electrothermal conductive coatings and / or metal conductors at the head and tail ends of the first, second, and third blood delivery tubes are connected to sensors via sensor connectors; the electrothermal conductive coatings and / or metal conductors of the first, second, and third blood delivery tubes are connected together and connected to an intelligent heating controller and several terminators. The intelligent heating controller outputs three levels of voltage: the first level of voltage drives the relay in the terminator to close, forming a closed circuit and causing the electrothermal conductive coating to generate heat; at the second level of voltage, the sensor switches to charging mode; and at the third level of voltage, the sensor performs data acquisition and communicates with the intelligent heating controller.

2. A blood-heating ECMO circulation kit according to claim 1, characterized in that: The two electroheating conductive coatings are two C-shaped electroheating conductive coatings arranged opposite to each other.

3. A blood-heating ECMO circulation kit according to claim 1, characterized in that: The two electrothermal conductive coatings are two sleeved tubular electrothermal conductive coatings, and a middle insulating layer is provided between the two tubular electrothermal conductive coatings.

4. A blood-heating ECMO circulation kit according to claim 1, characterized in that: The electrothermal conductive coating is tubular, and the metal wire is arranged in an outer insulating layer.

5. The blood-heating ECMO circulation kit according to claim 1, characterized in that: The three-level voltage has different values ​​at different ambient temperatures.

6. The blood-heating ECMO circulation kit according to claim 1, characterized in that: A first temperature sensor is provided at the head end of the first blood delivery tube; a second temperature sensor and a first pressure sensor are provided at the tail end of the first blood delivery tube; a second pressure sensor is provided at the head end of the second blood delivery tube; a third temperature sensor is provided at the tail end of the second blood delivery tube; a fourth temperature sensor and a third pressure sensor are provided at the head end of the third blood delivery tube; and a fifth temperature sensor is provided at the tail end of the third blood delivery tube.

7. The blood-heating ECMO circulation kit according to claim 1, characterized in that: The intelligent heating controller includes an electronic switch, a microprocessor, an RS485 communication unit, a current monitoring unit, a constant voltage power supply unit and a voltage control unit; the electronic switch is connected to the sensor connector through two wires, and is respectively connected to the constant voltage power supply unit and the RS485 communication unit through two wires; the microprocessor is connected to the voltage control unit, the current monitoring unit, the electronic switch and the RS485 communication unit, and the voltage control unit is connected to the constant voltage power supply unit; one end of the current monitoring unit is connected to the connection line between the constant voltage power supply unit and the electronic switch, and the other end is connected to the microprocessor.

8. The blood-heating ECMO circulation kit according to claim 1, characterized in that: The sensor connector includes a single-chip microcomputer system, an energy storage capacitor, a voltage-stabilized power supply, a voltage monitoring unit, an electronic switch and an RS485 interface; the electronic switch is connected to the electroheating conductive coating and / or the metal wire through two wires, and is respectively connected to the voltage-stabilized power supply and the RS485 interface through two wires; the single-chip microcomputer system is respectively connected to the energy storage capacitor, the sensor probe and the RS485 interface; the voltage monitoring unit is connected to the electronic switch and the connection line between the electronic switch and the voltage-stabilized power supply.

9. The blood-heating ECMO circulation kit according to claim 1, characterized in that: The terminator includes a voltage monitoring unit, a delay switch circuit, a relay and a delay switch circuit; a wire is connected to each end of the delay switch circuit, the relay and the voltage monitoring unit, and both wires at the two ends are connected to the electroheating conductive coating and / or the metal wire; the capacitor is connected to the delay switch circuit, and the voltage monitoring unit, the delay switch circuit and the relay are connected in sequence.

10. A method for controlling a blood-heating ECMO circulation kit according to any one of claims 1 to 9, characterized in that: The steps include: The intelligent heating controller outputs the first-level voltage, the relay in the terminator is closed, forming a closed loop, and the electrothermal conductive coating generates heat; The intelligent heating controller outputs the second level voltage and the sensor switches to charging mode; The intelligent heating controller outputs a third-level voltage, and the sensor collects data and communicates with the intelligent heating controller.

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