Multifunctional intracardiac stimulation test device

Abstract

The present invention relates to the field of medical device technology, and is about a multifunctional intracardiac stimulation test device for experimental animals. The device and dual pacing electrodes arranged on the test target form a test system, realize the intracardiac induction and defibrillation function, and realize the test of transcardiac current during the external defibrillation process. The device comprises: a power supply module, an intracardiac induction / defibrillation module, a transcardiac voltage measurement module and an interface module; the power supply module is used to supply power to other modules in the device; the intracardiac induction / defibrillation module is used to output an induction waveform or a defibrillation waveform to the test target; the transcardiac voltage measurement module obtains the transcardiac current of the test target by measuring the voltage between the external dual pacing electrodes placed outside the target ventricle.

Description

Technical Field

[0001] The present application relates to the technical field of medical equipment, and in particular to a multifunctional intracardiac stimulation testing device. Background Art

[0002] Before a defibrillator is put on the market, in the absence of equivalence tests, it must complete a certain number of clinical animal experiments on various weights and gender ratios in accordance with treatment efficacy and statistical principles. In experiments, it is almost impossible to achieve a 100% first-time defibrillation success rate and a 100% rescue success rate.

[0003] In actual applications, the actual success rate of defibrillator equipment is only close to 10% in countries and regions with a high AED deployment rate. The wearable automatic external defibrillator (WCD), which is the most timely emergency defibrillator, does not even reach a 100% success rate.

[0004] Transcardiac current is an indicator directly related to the success rate of defibrillation. It is generally believed that only when the transcardiac current is greater than a certain threshold and for a certain duration can the myocardial cells be uniformly depolarized, thereby terminating ventricular fibrillation or ventricular tachycardia and some life-threatening atrial fibrillation.

[0005] At present, there is no effective and mature equipment or simple and practical method in the world to measure transcardiac current.

[0006] The common understanding of measuring transcardiac current is to bury a sensor for testing current in the heart and export the information to an external device for processing and display. However, this is an invasive method that requires open-chest surgery. For minimally invasive defibrillation tests, the difficulty of burying electrode sensors for transcardiac current testing is much greater than minimally invasive cannulation surgery in the jugular artery and vein, and the incision surgery on the heart will greatly affect the defibrillation effect. Therefore, this method is actually not worth the cost and is not advisable.

[0007] In order to test the performance of defibrillator equipment, animal clinical experiments must be conducted. At present, the general pre-experimental surgery is mainly to implant temporary pacing electrodes (floating catheters) into the ventricles of experimental animals, and fix the end of the catheter in place on the skin of the neck to prevent the electrode from shifting, so as to induce intracardiac fibrillation multiple times through the electrode. The temporary intracardiac stimulation electrode is a complex pipeline with a length of nearly 1 meter; its top contains more than two electrodes composed of exposed metal rings, each electrode is insulated, and each electrode is led out to the external end with an independent metal wire; multiple electrode wires are then wrapped by an outer insulating layer into a thin wire several millimeters thick. The external induction device applies a small current to the metal ring at the top of the catheter through the wires of each electrode. Since the ring-mounted electrode exists in the blood, and some metal rings are in contact with the inner wall of the ventricle, the blood and the ventricular arm are both conductive. Therefore, when the induction current is applied between the ring electrodes, the ventricular cells will be electrically stimulated to induce ventricular fibrillation.

[0008] During the animal experiment, it is necessary to set up dual pacing electrodes at the experimental site of the animal to induce defibrillation. If the external defibrillator being tested fails to defibrillate the test animal successfully for several consecutive times, it is necessary to quickly use other third-party qualified and clinically verified external defibrillator equipment to perform emergency defibrillation on the animal, quickly rescue the animal from cardiac arrest, and restore the normal sinus rhythm of the experimental animal in time to avoid accidental death of the animal due to untimely treatment, which affects the progress of the experiment and the cost of the experiment. However, in actual experiments, due to the delay in the defibrillation failure of the external defibrillator being tested and other factors, the use of third-party external defibrillator equipment cannot save the life of the animal. Especially in the early stage of the test of the experimental equipment, the mortality rate of the experimental animals is very high. At this time, accurate, timely and effective intracardiac defibrillator equipment is very necessary to defibrillate through temporary pacing electrodes and perform intracardiac defibrillation in time to save the experimental animals. But in fact, this condition is also difficult to meet.

[0009] In clinical animal experiments, in addition to the functions of inducing cardiac fibrillation and defibrillation, two other objectives need to be studied:

[0010] 1. Is the reason for unsuccessful defibrillation related to insufficient transcardiac current? 2. What is the minimum threshold of transcardiac current for successful defibrillation? Both of these goals are related to transcardiac current measurement and intracardiac defibrillation. However, for a long time, due to the lack of available transcardiac current measurement equipment, it has been impossible to verify whether the defibrillation function of experimental equipment such as defibrillators is effective based on the size of the ECG current. Summary of the invention

[0011] In order to overcome the problems existing in the related art, the present application provides a multifunctional intracardiac stimulation test device having multiple functions such as transcardiac current measurement, intracardiac defibrillation, and intracardiac induced fibrillation.

[0012] To achieve the above object, the present invention adopts the following technical solution:

[0013] The first aspect of the present application provides a multifunctional intracardiac stimulation test device, which can form a test system with dual pacing electrodes arranged on a test target. It can realize the intracardiac induction function, and after the defibrillation of the tested external defibrillator fails, the system can be used to accurately and timely rescue the experimental animal and effectively avoid the death of the experimental animal.

[0014] The device comprises: a power supply module, an intracardiac fibrillation / defibrillation module, a transcardiac voltage measurement module and an interface module;

[0015] The power supply module is used for supplying power; the output end of the power supply module is respectively connected to the power supply input end of the intracardiac fibrillation / defibrillation module and the power supply input end of the transcardiac voltage measurement module;

[0016] The intracardiac fibrillation induction / defibrillation module is used to output a fibrillation induction waveform or a defibrillation waveform to the test target; a first output end of the intracardiac fibrillation induction / defibrillation module is connected to a first end of the dual pacing electrodes via a first single-pole double-throw switch of a first terminal of the interface module, and a second output end of the intracardiac fibrillation induction / defibrillation module is connected to a second end of the dual pacing electrodes via a second single-pole double-throw switch of a second terminal of the interface module;

[0017] The intracardiac fibrillation / defibrillation module comprises an inter-electrode bioimpedance measurement unit for measuring the bioimpedance of the intracardiac tissue of the test target;

[0018] The transcardiac voltage measurement module is used to measure the transcardiac voltage generated during the defibrillation process of an external defibrillator; and to obtain the transcardiac current of the test target based on the measured bioimpedance measured by the intracardiac fibrillation / defibrillation module; the first end of the transcardiac voltage measurement module is connected to the first end of the dual pacing electrode through the first terminal of the interface module, and the second end of the transcardiac voltage measurement module is connected to the second end of the dual pacing electrode through the second terminal of the interface module.

[0019] In some embodiments, the intracardiac fibrillation / defibrillation module includes a fibrillation / defibrillation waveform generation unit and a signal amplitude and power drive output unit;

[0020] The inducing / defibrillating waveform generating unit is used for generating inducing waveforms and defibrillating waveforms, and the inducing waveforms are output to the signal amplitude and power driving output unit;

[0021] The signal amplitude and power drive output unit is used to adjust the amplitude and amplify the current of the signal output by the inducing fibrillation / defibrillation waveform generating unit according to the selected inducing fibrillation signal strength to form an inducing fibrillation signal.

[0022] In some embodiments, the inducing fibrillation waveform generating module in the inducing fibrillation / defibrillation waveform generating unit is always in operation, outputting a power frequency sine wave, a triangle wave or a pulse wave.

[0023] In some embodiments, the interface module includes a tremor induction button and its corresponding intensity knob.

[0024] In some embodiments, the intensity knob includes at least five stimulation intensities: 5mV, 10mV, 15mV, 20mV, and 25mV.

[0025] In some embodiments, the interface module includes a defibrillation button and its corresponding energy knob.

[0026] In some embodiments, the energy knob includes at least five defibrillation energy levels of 5J, 10J, 15J, 20J, and 30J.

[0027] In some embodiments, the power module uses an AC power source for external power supply; the internal AC-DC unit converts the power into a DC power source to power the internal modules of the device, and at the same time charges the internal rechargeable battery; when the AC adapter is not used for power supply, the device is powered by the internal rechargeable battery.

[0028] In some embodiments, the transcardiac voltage measurement module specifically includes: a signal input protection unit, a multi-range signal processing unit, a transcardiac voltage digitization unit, a transcardiac voltage visualization unit, a transcardiac voltage storage unit and a remote communication unit connected in sequence;

[0029] The multi-range signal processing unit is used to amplify or attenuate the input signal to a set range.

[0030] In some embodiments, the multi-range signal processing unit includes at least four filtering circuits and one driving circuit.

[0031] In some embodiments, the transcardiac voltage digitization unit includes an independent ADC chip, which performs round-robin sampling on the signals input by four filtering circuits and one driving circuit, and records the collected data in a transcardiac voltage storage unit. The transcardiac voltage digitization unit can automatically calculate the average transcardiac voltage of each channel.

[0032] In some embodiments, the inter-electrode bioimpedance measurement unit is used to calculate the bioimpedance of the test target based on the current and voltage output to the dual pacing electrodes.

[0033] The second aspect of the present application provides a testing method, by using the bioimpedance between the dual pacing electrodes measured during induction of fibrillation using the system of the present invention, and measuring the transcardiac voltage applied between the dual pacing electrodes during defibrillation by an external defibrillator, thereby obtaining the transcardiac current waveform and value of the external defibrillation process, which is used to study and evaluate the defibrillation efficacy of the external defibrillator.

[0034] The present application also provides a method for testing a transcentric current, the method comprising:

[0035] Recording the current and voltage output by the test device to the dual pacing electrodes after the induction button is pressed, and calculating the bioimpedance of the test target based on the recorded current and voltage;

[0036] When the external defibrillator performs discharge therapy, the transcardiac current of the test target is calculated based on the voltages of the dual pacing electrodes and the bioimpedance.

[0037] The technical solution provided by this application may have the following beneficial effects:

[0038] The present invention and the dual pacing electrodes arranged on the test target form a test system, the intracardiac induction / defibrillation module includes an inter-electrode bioimpedance measurement unit to measure the bioimpedance of the intracardiac tissue of the test target; the transcardiac voltage measurement module obtains the transcardiac current of the test target based on the transcardiac voltage generated during the defibrillation process of the external defibrillator between the dual pacing electrodes and the bioimpedance. In addition to the general intracardiac induction function, a device with an intracardiac defibrillation first aid function, an intracardiac transcardiac voltage, impedance, and transcardiac current measurement function is also provided, which can measure the transcardiac current, and then verify whether the defibrillation function of experimental equipment such as a defibrillator is effective according to the size of the electrocardiac current.

[0039] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0041] Figure 1 is a schematic diagram of the system functional structure of a multifunctional intracardiac stimulation device provided in an embodiment of the present application;

[0042] Figure 2 is a schematic diagram of a transcardiac voltage waveform displayed by a display module in an embodiment of the present application;

[0043] Figure 3It is a flow chart of a method for testing a transcardial current provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0045] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0046] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0047] The present application provides a multifunctional intracardiac stimulation test device, which not only has the intracardiac induction function, but also has the intracardiac defibrillation function, and can also provide effective data support of transcardiac current to determine whether the defibrillation function of the external defibrillator is effective. It turns a very simple and common intracardiac induction device into an intracardiac defibrillator that can also perform first aid; intracardiac defibrillator equipment costs hundreds of thousands, while an intracardiac induction device does not exceed 3,000 yuan. The present application can extract the intracardiac defibrillation function of the expensive defibrillator and integrate it into the invented device, thereby improving the convenience of the test and the timeliness of the treatment.

[0048] See also Figure 1 , Figure 1 It is a schematic diagram of the system functional structure of a multifunctional intracardiac stimulation device provided in this application.

[0049] The present application provides a multifunctional intracardiac stimulation test device 10, comprising dual pacing electrodes 140 disposed on a test target.

[0050] In the prior art, before conducting an experiment, the test target is usually provided with dual pacing electrodes. For example, a temporary pacing electrode (floating catheter) is implanted in the ventricle of an experimental animal, and the end of the catheter in a straight position is fixed on the skin of the neck to prevent the electrode from shifting, so that multiple intracardiac pacing or fibrillation induction can be performed through the electrode. In actual experiments, the temporary intracardiac stimulation electrode is a complex pipeline with a length of nearly 1 meter; its top contains electrodes composed of more than two exposed metal rings, each electrode is insulated, and each electrode is led out to the external end with an independent metal wire; multiple electrode wires are then wrapped by an outer insulating layer into a thin wire several millimeters thick. The external fibrillator applies a small current to the metal ring at the top of the catheter through the wires of each electrode. Since the ring-mounted electrode exists in the blood, and some metal rings are in contact with the inner wall of the ventricle, the ventricular cells will be electrically stimulated to induce ventricular fibrillation.

[0051] Based on the dual pacing electrodes that have been set up in the prior art, the embodiment of the present application is further provided with a power supply module 100, an intracardiac fibrillation / defibrillation module 120, a transcardiac voltage measurement module 130, and an interface module 110. Through the connection with the dual pacing electrodes 140, the functions of intracardiac fibrillation, intracardiac defibrillation, and ECG current detection of the test target are realized.

[0052] Specifically, the functions of each part are as follows:

[0053] The power module 100 is used for supplying power; the output end of the power module 100 is respectively connected to the power input end of the intracardiac fibrillation / defibrillation module 120 and the power input end of the transcardiac voltage measurement module 130.

[0054] The intracardiac fibrillation / defibrillation module 120 is used to output a fibrillation waveform or a defibrillation waveform to the test target; the first output end of the intracardiac fibrillation / defibrillation module 120 is connected to the first end of the dual pacing electrode 140 through a first single-pole double-throw switch of the first terminal 111 of the interface module 110, and the second output end of the intracardiac fibrillation / defibrillation module 120 is connected to the second end of the dual pacing electrode 140 through a second single-pole double-throw switch of the second terminal 112 of the interface module 110.

[0055] The intracardiac fibrillation / defibrillation module includes an inter-electrode bioimpedance measurement unit for measuring the bioimpedance of the intracardiac tissue of the test target; specifically, when the device's fibrillation induction button 113 is pressed, the intracardiac fibrillation / defibrillation module 120 outputs the fibrillation induction waveform and current while measuring the actual output voltage and the defibrillation circuit current, thereby calculating the bioimpedance between the two ring electrodes of the dual pacing electrodes for subsequent transcardiac current measurement.

[0056] The transcardiac voltage measurement module 130 is used to test the transcardiac current of the test target based on the voltage between the dual pacing electrodes 140; the first end of the transcardiac voltage measurement module 130 is connected to the first end of the dual pacing electrodes 140 through the first terminal 111 of the interface module 110, and the second end of the transcardiac voltage measurement module 130 is connected to the second end of the dual pacing electrodes 140 through the second terminal 112 of the interface module 110.

[0057] In the embodiment of the present application, the interface module 110 includes a tremor inducing button 113 and a corresponding intensity knob 114. The intensity knob 114 includes at least five scales of 5mV, 10mV, 15mV, 20mV, and 25mV. Each scale can correspond to a current intensity when tremor is induced.

[0058] In the embodiment of the present application, the interface module 110 includes a defibrillation button 115 and a corresponding energy knob 116. The energy knob 116 includes at least five scales of 5J, 10J, 15J, 20J, and 30J. Each scale corresponds to an energy value during defibrillation.

[0059] In the embodiment of the present application, the power module 100 includes a DC power unit and an AC power unit. The DC power unit includes a rechargeable battery 103, and the AC power unit is connected to an AC adapter 101.

[0060] In the embodiment of the present application, the transcardiac voltage measurement module specifically includes: a signal input protection unit 131, a multi-range signal processing unit 132, a transcardiac voltage digitization unit 133, a transcardiac voltage visualization unit 134, a transcardiac voltage storage unit 135 and a remote communication unit 136, which are connected in sequence. The transcardiac voltage digitization unit 133 includes an independent ADC chip.

[0061] The function of the signal input protection unit 131 is that after the signal is input, since the circuit has a voltage of thousands of volts, due to the existence of the signal input protection unit 131, there is no contact with the outside world, and the anti-defibrillation circuit will not damage the device. Specifically, this embodiment can use a lightning strike tube, which is a normal double-electric tube, such as a TPS tube; it can prevent lightning strikes from striking the circuit, prevent instantaneous high voltage, and play an overvoltage protection role.

[0062] The function of the multi-range signal processing unit 312 is: due to the different digital signals, the regular data range is 30-40V, and it is just a few volts when not active. Large signals are attenuated and small signals are amplified. For multiple amplification or attenuation circuits, saturation is determined based on the digital signal.

[0063] The voltage digitization unit 133 is used for digital sampling. After digitization, the multi-range signal processing unit 132 is used. Usually five channels are used, and the sampling voltage does not exceed 3V.

[0064] The transcardiac voltage visualization unit 134 is used for screen display, such as conventional parameter display.

[0065] The transcardial voltage storage unit 135 stores parameters such as defibrillation time, waveform, current, etc. after testing.

[0066] The specific functions and operating principles of each module in the device of the present application are described in detail below.

[0067] In the embodiment of the present application, the power module 100 of the device is responsible for the power supply of the device. When the AC adapter 101 is used as the external power input, the AC 101 converts the 220V / 110V AC point into a DC 12V output voltage through the AC-DC circuit to power the device. The input 12V DC power charges the rechargeable battery 103 through the charging management circuit 102, and at the same time, the DC input is converted into multiple 3.3V, ±5V, ±12V and other voltages through the power conversion circuit 104 for the transcardiac voltage measurement module 130 and the intracardiac fibrillation / defibrillation module 120 to work; when only the internal rechargeable battery 103 is used for power supply, the voltage output of the rechargeable battery 103 is converted into multiple 3.3V, ±5V, ±12V and other voltages through the power conversion circuit 104 for the transcardiac voltage measurement module 130 and the intracardiac fibrillation / defibrillation module 120 to work.

[0068] In the embodiment of the present application, the interface module 110 of the device includes two terminals, namely a first terminal 111 and a second terminal 112 , an induction button 113 , an intensity knob 114 , a defibrillation button 115 and an energy knob 116 .

[0069] The first terminal 111 and the second terminal 112 are externally connected to two metal guide wires of the dual pacing electrode 140, and have three functions:

[0070] 1) During the experiment, the output of the inducing fibrillation signal is to induce ventricular fibrillation in the test target, such as the heart of the experimental animal;

[0071] 2) After induction of defibrillation, the experimental equipment cannot effectively defibrillate and emergency treatment is required to avoid intracardiac defibrillation, such as death of the experimental animal;

[0072] 3) During defibrillation treatment by the external defibrillation experimental device, the transcardiac voltage on the two annular metal electrodes at the front end of the intracardiac catheter is transmitted to the transcardiac voltage measurement module 130 of the device.

[0073] When the experimenter presses the induction button 113, the first terminal 111 and the second terminal 112 are connected to the induction signal output module inside the device, and the induction signal is transmitted to the two annular metal electrodes at the front end of the catheter via the metal guide wire through the connector at the end of the catheter. As long as the amplitude of the induction signal is large enough and the button is pressed for a long enough time, multiple myocardial tissues on the heart receive unexpected stimulation and are in a high-frequency self-contraction and relaxation state, the heart of the experimental subject can be inducing fibrillation. Thus, the induction of fibrillation is successful.

[0074] When the experimenter needs to perform emergency treatment on the clinical animal to get out of the ventricular fibrillation state, he presses the defibrillation button 115 for intracardiac defibrillation treatment, and the intracardiac defibrillation / defibrillation module 120 outputs a triangular square wave or a biphasic square wave for intracardiac defibrillation. After being driven, the defibrillation waveform passes through the first terminal 111 and the second terminal 112, and is applied to the front end of the catheter in the heart via the guide wire to perform intracardiac defibrillation on the heart, thereby achieving the purpose of timely treatment of the experimental animals.

[0075] The signal strengths that can be selected by the intensity knob 114 are: 5, 10, 15, 20, 25mV, a total of 5 scales; and the energy values ​​that can be selected by the energy knob are: 5J, 10J, 15J, 20J, 30J, etc.

[0076] It should be noted that the intracardiac fibrillation / defibrillation module 120 and the transcardiac voltage measurement module 130 are two independent modules and will not work at the same time.

[0077] The intracardiac induction / defibrillation module 120 has two functions: intracardiac induction and intracardiac defibrillation, which is composed of an induction / defibrillation waveform generating unit 121 and a signal amplitude and power drive output unit 122. The functions of the induction / defibrillation waveform generating unit 121 are divided into induction waveform generation and defibrillation waveform generation, wherein the induction waveform generating module is always in operation, outputting a 50Hz industrial frequency sine wave, a triangle wave or a pulse wave similar to nerve conduction, and the induction waveform is output to the signal amplitude and power drive output unit 122, which adjusts the amplitude and amplifies the current of the signal output by the induction / defibrillation waveform generating unit 121 according to the intensity of the induction signal selected by the intensity knob 114 on the panel, to form an induction signal with a certain driving power, and when the induction button is pressed, the signal is loaded on the end ring electrode of the catheter in the ventricle to cause the experimental animal to vibrate.

[0078] When the intracardiac defibrillator button 115 is pressed, the defibrillator waveform generating unit 121 reads out a solidified defibrillator waveform according to the waveform category selected by the system setting, such as a biphasic square wave, a biphasic triangular square wave or a sine wave which are very mature in the industry, and outputs it to the amplification and power drive output unit 122. The power drive output unit 122 amplifies the voltage and current of the output waveform according to the defibrillator energy set by the energy knob 116 and the internal setting of the device, and then applies it to the ventricular pacing electrode at the front end of the intracardiac catheter through the first terminal 111 and the second terminal 112 through the first single-pole double-throw switch and the second single-pole double-throw switch respectively. The defibrillator current passes through the intraventricular blood or the ventricular muscle next to the metal electrode, and transmits the electrical stimulation to the entire ventricular cells in ventricular fibrillation, forcing them to depolarize synchronously, thereby relieving the irregular state of autonomous contraction and relaxation of the myocardium of each ventricular module, and achieving the purpose of defibrillation.

[0079] Only when the induction button 113 or the defibrillation button 115 is pressed, the first terminal 111 and the second terminal 112 in the interface module 110 are connected to the power drive output unit 122 by the internal isolation switch, such as the first single-pole double-throw switch and the second single-pole double-throw switch. At other times, the first terminal 111 and the second terminal 112 are switched to the signal input protection unit 131 of the transcardiac voltage measurement module 130 by the internal isolation switch.

[0080] The transcardiac voltage measurement module 130 mainly includes functions of a signal input protection unit 131, a multi-range signal processing unit 132, a transcardiac voltage digitization unit 133, a transcardiac voltage visualization unit 134, a transcardiac voltage storage unit 135 and a remote communication unit 136.

[0081] The transcardiac voltage between two ring-shaped metal electrodes measured by a temporary intracardiac pacing catheter ranges from 10mV to 50V. In mature products such as pacemakers and AED devices, the maximum value measured when the biphasic square wave pediatric mode outputs 85J of defibrillation energy is 25V, and the maximum voltage between the electrodes measured when the adult mode outputs 200J of defibrillation energy is no more than 35V; if a biphasic exponential cutoff wave of 360J discharge defibrillation is used, the maximum transcardiac voltage between the two electrodes may reach 50V. If the electrode patch is offset so that the discharge path does not completely pass through the heart or deviates from the heart, the voltage measured between the two ring-shaped metal electrodes in the ventricle is at the millivolt level, several millivolts or even tens of millivolts.

[0082] It can be seen that in order to meet the needs of product testing, the range of the transverse voltage to be measured in the device should be 10mV to 50V. In order to process the input signal with a large dynamic range as above, the small signal must be amplified to 1V-2V and the large signal must be attenuated to 1V-2V. This is because when displaying, it is usually based on the display method of the oscilloscope, and the oscilloscope is usually displayed in millivolts, for example, divided into 1 / 2 / 5 / 10 / 20 / 50 / 100 / 200 / 500 / 1000 / 2000 / 5000 / 10000mV for better display. Therefore, the above setting can prevent the small signal from being displayed as a straight line and the large signal from being incompletely displayed. However, detecting the maximum value of the signal during the display process and then adjusting the amplification or attenuation coefficient will cause signal loss.

[0083] Therefore, the device in the present application adopts multi-speed parallel processing to achieve the effect of automatic range processing of the signal. Combined with the amplitude characteristics of the signal, four parallel signal processing circuits of 100mV, 500mV, 2000mV, and 10000mV are determined, and the amplification factor is fixed according to 20 / 4 / 1 / (0.2|0.02); for signals with excessive amplitudes of about 50V, an attenuation of 0.2 is not enough, so the signal output is attenuated at 0.2, and then a simple resistance attenuation method is used to output another attenuation coefficient of 0.02 to meet the large amplitude signal of about 50V. These four parallel signal filtering and driving circuits and five signal outputs constitute a multi-range signal processing unit 132. That is, the multi-range signal processing unit includes at least four filtering circuits and one driving circuit.

[0084] The transcardiac voltage digitization module 133 uses an independent ADC chip to sample the five signals input by the five circuits using relevant mature technology, and records the collected data in the ring memory of the controller. The transcardiac voltage digitization unit can automatically calculate the average transcardiac voltage of each channel within 0.5-1 milliseconds.

[0085] In actual use, detection starts from the first channel of the 100mV range. If the average data is saturated, the next channel with a larger range is detected until an unsaturated signal is found. This signal is used as the signal to be displayed later, and the signal with the best sampling value is passed to the core voltage storage unit 135 for storage.

[0086] The transcardiac voltage visualization unit 134 automatically generates an amplitude scale suitable for optimal display according to the finally selected channel on a display module such as a screen, and displays the complete transcardiac voltage waveform together with the data.

[0087] refer to Figure 2 , Figure 2It is the transcardiac voltage waveform diagram displayed by the display module in the embodiment of the present application. By measuring and displaying the waveform and change trend of transcardiac voltage and transcardiac current, and according to the actual effect of success or failure of external defibrillation, the optimal / minimum threshold of effective defibrillation energy of the defibrillation target, the effective threshold of transcardiac current, and the relationship between clinical statistics of optimal defibrillation waveform and energy size and age, weight, gender, etc., as well as the differences and causes of different defibrillation waveforms, and other basic principles that are currently unknown.

[0088] The remote communication unit 136 is responsible for exporting the time point and waveform type, signal strength / output energy and other information of the recorded induced fibrillation / defibrillation events, as well as the stored transcardial voltage information, to a mobile storage medium, and, when the WIFI / 4G network is unobstructed, transmitting this information to a remote data center for storage for later big data processing and analysis.

[0089] In actual use, the normal working order of the equipment is:

[0090] 1) After intubation, turn on the device. If the battery is low, plug in the AC power to charge the device and power on the device.

[0091] 2) Check the induction knob 113 and select the appropriate signal strength (usually 5mV is selected first); press the induction button 113 and hold for 0.5 to 1 second, and release the induction button if the subject's electrocardiogram is in ventricular fibrillation rhythm; if the subject's heart rhythm returns to normal after induction, select the next level of induction signal strength until the selected strength can successfully induce fibrillation every time the button is pressed;

[0092] 3) Wait for external defibrillator to perform discharge therapy, and observe the transcardiac current waveform on the device screen after discharge, as well as some important parameters calculated, such as the first item average voltage, calculated transcardiac current, etc.

[0093] During the experiment, if defibrillation is unsuccessful, the magnitude of the transcardiac voltage can be monitored to determine whether the defibrillation current has passed through the test target, such as the heart of the experimental pig. If the transcardiac voltage is large but defibrillation is not successful, cardiac physiological first aid and blood pressure and blood gas first aid should be performed; if the transcardiac voltage is low, it means that the impedance is large, check whether the electrode is well pasted, whether the electrode is in good contact, or the defibrillation electrode is not pasted in an unreasonable position, resulting in the defibrillation current path not covering or partially covering the heart; successful defibrillation is related to the magnitude and duration of the defibrillation current. As long as the voltage applied to the myocardial cells is greater than a certain threshold and lasts for a certain period of time, the entire ventricular myocardial cells will be depolarized and maintained until all cells begin to repolarize uniformly, thereby achieving the effect of restoring the heart to normal physiological rhythm.

[0094] Therefore, the optimal defibrillation waveform and defibrillation current are measured by finding the transcardiac current threshold and duration threshold, or output power. Of course, different waveforms, such as the most commonly used biphasic square wave, biphasic exponential cutoff wave, and biphasic multi-pulse wave, have different transcardiac current thresholds, duration thresholds, and output energy thresholds.

[0095] However, through the device described in this application, the intracardiac impedance is measured by inducing defibrillation, and the transcardiac current is measured by the transcardiac voltage. Through these parameters, the effectiveness of the experimental equipment can be more deeply evaluated and studied, and a means of studying and optimizing existing defibrillation waveforms and discharge processes is provided.

[0096] This embodiment can have the following beneficial effects:

[0097] 1. Through the core current measurement method, measure the display storage system.

[0098] 2. The intracardiac defibrillation function is added to the intracardiac defibrillation output part, so that the intracardiac defibrillation treatment can be carried out in time when the external defibrillator fails to defibrillate, thus avoiding the death of experimental animals.

[0099] 3. Complete testing equipment for experiments with functions of intracardiac induction, intracardiac defibrillation, and transcardiac voltage measurement; as well as calculation of intracardiac defibrillation impedance, calculation of transcardiac current, and display and storage.

[0100] It can be seen that the embodiments of the present application can measure the electrocardiographic current, and then verify whether the defibrillation function of experimental equipment such as a defibrillator device is effective according to the size of the electrocardiographic current.

[0101] Based on the above device, Figure 3 As shown, the present application also provides a method for testing a transcentric current, the testing method comprising:

[0102] S100, recording the current and voltage output by the test device to the dual pacing electrodes after the induction button 113 is pressed, and calculating the bioimpedance of the test target based on the recorded current and voltage;

[0103] S200. When an external defibrillator performs discharge therapy, the transcardiac current of the test target is calculated based on the voltage of the dual pacing electrodes and the bioimpedance.

[0104] Based on the above-mentioned device of the present application, when inducing defibrillation, the output voltage and the output current are measured, and the bioimpedance between the two ring-shaped metal electrodes can be calculated; during discharge therapy, the measured transcardiac voltage is the divided voltage of the external defibrillation voltage on the biological tissue between the ring electrodes inside the heart; therefore, according to Ohm's law, using this voltage and the bioimpedance measured when inducing defibrillation, the transcardiac current on the biological tissue (blood or ventricular myocardial tissue) between the ring metal electrodes inside the ventricle can be calculated.

[0105] The recording process may refer to the specific principles and working processes of each unit of the transcardiac voltage measurement module in the aforementioned embodiment, which will not be elaborated here.

[0106] It can be seen that through the method of the present invention, the intracardiac impedance is measured by inducing defibrillation, and the transcardiac current is measured by the transcardiac voltage. Through these parameters, the effectiveness of the experimental equipment can be more deeply evaluated and studied, and a means of studying and optimizing existing defibrillation waveforms and discharge processes is provided.

[0107] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of the various embodiments have their own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the specification are not necessarily required for the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0108] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A multifunctional intracardiac stimulation test device for experimental animals, the device being capable of forming a test system with dual pacing electrodes arranged on a test target, characterized in that: The device comprises: a power supply module, an intracardiac fibrillation / defibrillation module, a transcardiac voltage measurement module and an interface module; The power module is used for power supply; the output end of the power module is respectively connected to the power input end of the intracardiac fibrillation / defibrillation module and the power input end of the transcardiac voltage measurement module; The intracardiac fibrillation induction / defibrillation module is used to output a fibrillation induction waveform or a defibrillation waveform to the test target; a first output end of the intracardiac fibrillation induction / defibrillation module is connected to a first end of the dual pacing electrodes via a first single-pole double-throw switch of a first terminal of the interface module, and a second output end of the intracardiac fibrillation induction / defibrillation module is connected to a second end of the dual pacing electrodes via a second single-pole double-throw switch of a second terminal of the interface module; The intracardiac fibrillation / defibrillation module comprises an inter-electrode bioimpedance measurement unit for measuring the bioimpedance of the intracardiac tissue of the test target; The transcardiac voltage measurement module is used to measure the transcardiac voltage generated during the defibrillation process of the external defibrillator, and to obtain the transcardiac current of the test target based on the bioimpedance measured by the internal induction / defibrillator module; the first end of the transcardiac voltage measurement module is connected to the first end of the dual pacing electrode through the first terminal of the interface module, and the second end of the transcardiac voltage measurement module is connected to the second end of the dual pacing electrode through the second terminal of the interface module.

2. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The intracardiac fibrillation / defibrillation module comprises a fibrillation / defibrillation waveform generating unit and a signal amplitude and power driving output unit; The inducing / defibrillating waveform generating unit is used for generating inducing waveforms and defibrillating waveforms, and the inducing waveforms are output to the signal amplitude and power driving output unit; The signal amplitude and power drive output unit is used to adjust the amplitude and amplify the current of the signal output by the inducing fibrillation / defibrillation waveform generating unit according to the selected inducing fibrillation signal strength to form an inducing fibrillation signal.

3. The multifunctional intracardiac stimulation test device according to claim 2, characterized in that: The inducing fibrillation waveform generating module in the inducing fibrillation / defibrillation waveform generating unit is always in operation, outputting a power frequency sine wave, a triangle wave or a pulse wave.

4. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The interface module includes a tremor induction button and a corresponding intensity knob; the intensity knob includes at least five stimulation intensities of 5mV, 10mV, 15mV, 20mV, and 25mV.

5. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The interface module includes a defibrillation button and a corresponding energy knob; the energy knob includes at least five defibrillation energy levels of 5J, 10J, 15J, 20J and 30J.

6. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The power module uses an AC power supply for external power supply; the internal AC-DC unit converts the power into a DC power supply to power the internal modules of the device and charges the internal rechargeable battery at the same time; when the AC adapter is not used for power supply, the device is powered by the internal rechargeable battery.

7. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The transcardiac voltage measurement module specifically includes: a signal input protection unit, a multi-range signal processing unit, a transcardiac voltage digitization unit, a transcardiac voltage visualization unit, a transcardiac voltage storage unit and a remote communication unit connected in sequence; The multi-range signal processing unit is used to amplify or attenuate the input signal to a set range.

8. The multifunctional intracardiac stimulation test device according to claim 7, characterized in that: The multi-range signal processing unit includes at least four filtering circuits and one driving circuit.

9. The multifunctional intracardiac stimulation test device according to claim 8, characterized in that: The transcardiac voltage digitization unit includes an independent ADC chip, which samples the signals input by four filtering circuits and one driving circuit in a round-robin manner, and records the collected data in the transcardiac voltage storage unit. The transcardiac voltage digitization unit can automatically calculate the average transcardiac voltage of each channel.

10. The multifunctional intracardiac stimulation test device according to claim 1, characterized in that: The inter-electrode bioimpedance measurement unit is used to measure the current and voltage output to the dual pacing electrodes during induction of fibrillation, and calculate the bioimpedance of the test target based on the current and voltage.

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