CN115040230A - Pulsed electric field ablation system and electronic equipment - Google Patents

Abstract

The application discloses pulsed electric field melts system and electronic equipment, and the technical field who belongs to is the pipe ablation technique, and pulsed electric field melts the system and includes: the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter; the electrical stimulation device is used for electrically stimulating the nerve of the target part through the electrical stimulation catheter so as to block local conduction of the nerve; wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part. The muscle twitch that the pulsed electric field ablation operation arouses can be reduced on the basis of improving operation safety and efficiency to this application.

Description

Pulsed electric field ablation system and electronic equipment

Technical Field

The application relates to the technical field of catheter ablation, in particular to a pulsed electric field ablation system and electronic equipment.

Background

Pulsed electric fields are currently used in the fields of tumor, cardiac ablation, etc. because of their safety and rapidity. However, as a side effect of this technique, the pulsed electric field requires a large instantaneous current (of the order of 10A) to be applied to the body tissue, and the neuronal cells in the tissue are excited by the current and are transmitted down to the body through the nerve fibers, resulting in muscle twitching in the abdomen, limbs, and even the whole body. Such muscle twitches may further cause problems such as displacement of the patient's body, displacement of the catheter from the treatment site, perforation of the catheter, displacement of the heart chamber model on the three-dimensional system, etc., and may also psychologically cause panic and startle of the patient.

In order to reduce the phenomenon of muscle twitching during pulsed electric field ablation, it is common in the related art to subject the patient to general anesthesia or to inject muscle relaxants into the patient prior to ablation. However, after general anesthesia, the patient is completely unconscious and cannot subjectively alert the physician. If the muscle relaxant is injected in parallel, the patient loses his own breath due to the drug being a systemic nerve transmission blocker, and thus relies on an external ventilator to provide the oxygen needed for production, which may risk the ventilator to malfunction, resulting in the patient dying. Furthermore, general anesthesia is performed by a doctor licensed by an anesthesiologist, a cardiologist who performs ablation of atrial fibrillation usually has no related qualification, and the ablation of atrial fibrillation under general anesthesia can be performed in the presence of a doctor in an anesthesia department of a hospital. The patient after general anesthesia also needs several hours of process of reviving after the postoperative, and this process needs medical personnel's control, has reduced operation efficiency.

Therefore, how to reduce the muscle twitching caused by the pulsed electric field ablation operation on the basis of improving the safety and efficiency of the operation is a technical problem to be solved by the technical personnel in the field at present.

Disclosure of Invention

The utility model aims at providing a pulsed electric field ablation system and an electronic equipment can reduce the muscle twitch that pulsed electric field ablation operation arouses on the basis of improving operation safety and efficiency.

In order to solve the above technical problem, the present application provides a pulsed electric field ablation system, including:

the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter;

the electrical stimulation device is used for electrically stimulating the nerve of the target part through the electrical stimulation catheter so as to block local conduction of the nerve;

wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

Optionally, a communication connection exists between the pulse ablator and the electrical stimulation device;

the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter at a preset moment; wherein the preset time is later than or equal to the time of the electrical stimulation device for electrical stimulation.

Optionally, the pulsed electric field ablation system further comprises a three-dimensional mapping navigation device;

the three-dimensional mapping navigation device is connected with the pulse ablation instrument and is used for displaying the position of the ablation catheter;

and/or the three-dimensional mapping navigation device is connected with the electrical stimulation equipment, and the three-dimensional mapping navigation device is used for displaying the position of the electrical stimulation catheter.

Optionally, the electrical stimulation device comprises a stimulation signal controller and a stimulation signal generator;

the stimulation signal controller is used for controlling the signal output sequence and the signal waveform of the stimulation signal generator;

the stimulation signal generator is used for inputting an electrical stimulation signal to the electrical stimulation catheter according to a control instruction of the stimulation signal controller.

Optionally, the stimulation signal generator includes a direct current stimulation signal generator and an alternating current stimulation signal generator.

Optionally, the electrical stimulation catheter comprises a plurality of electrodes thereon;

the electrical stimulation equipment is further used for selecting an electrode closest to the target part as a target electrode so as to output the same electrical stimulation signal through the target electrode at the same time to electrically stimulate the nerve of the target part.

Optionally, the process of controlling the direct current stimulation signal generator and the alternating current stimulation signal generator by the stimulation signal controller to input the electrical stimulation signal to the target electrode of the electrical stimulation catheter includes:

controlling the direct current stimulation signal generator to input continuously increased cathodal electrical stimulation signals;

when the target part forms a direct current block, controlling the alternating current stimulation signal generator to input an alternating current stimulation signal, and controlling the direct current stimulation signal generator to keep the input cathodal electrical stimulation signal unchanged within a preset time period;

and controlling the direct current stimulation signal generator to reduce the input cathode electrical stimulation signal so that the direct current stimulation signal generator inputs an anode electrical stimulation signal according to a preset rule until the anode electrical stimulation signal and the cathode electrical stimulation signal reach charge balance.

Optionally, the electrical stimulation catheter comprises a plurality of electrodes thereon;

the electrical stimulation equipment is also used for selecting 2 electrodes closest to the target part as a direct current discharge electrode and an alternating current discharge electrode so as to output a direct current electrical stimulation signal through the direct current discharge electrode to electrically stimulate the nerve of the target part and output an alternating current electrical stimulation signal through the alternating current discharge electrode to electrically stimulate the nerve of the target part.

Optionally, the alternating current stimulation signal generator is configured to generate an alternating current stimulation signal with a sine wave shape.

The application also provides an electronic device, which is connected with the pulse ablation instrument and the electrical stimulation device respectively, and comprises a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program in the memory to realize the following steps:

controlling the pulse ablation instrument to perform pulse electric field ablation operation on a part to be ablated through an ablation catheter;

controlling the electrical stimulation device to electrically stimulate nerves at the target site through the electrical stimulation catheter so as to block local conduction of the nerves;

wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

The present application further provides a storage medium having stored thereon a computer program which, when executed, performs the steps performed by the pulsed electric field ablation method described above.

The present application provides a pulsed electric field ablation system comprising: the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter; the electrical stimulation device is used for electrically stimulating the nerve of the target part through the electrical stimulation catheter so as to block local conduction of the nerve; wherein the output current of the electrical stimulation device is smaller than the output current of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

The pulsed electric field ablation system provided by the application comprises a pulsed ablation instrument and an electrical stimulation device, wherein the pulsed ablation instrument is used for executing pulsed electric field ablation operation on a part to be ablated, and muscle twitches can be caused due to the fact that the current of the pulsed electric field ablation operation is large. The present application uses an electrical stimulation device to electrically stimulate a target site between a site to be ablated and a site of muscle twitch such that nerve conduction at the target site is blocked. The scheme can reduce the muscle twitch condition caused by the pulse electric field ablation operation by using the electrical stimulation equipment without performing general anesthesia and injecting muscle relaxant on a patient, and can reduce the muscle twitch caused by the pulse electric field ablation operation on the basis of improving the safety and efficiency of the operation. This application still provides an electronic equipment simultaneously, has above-mentioned beneficial effect, no longer gives unnecessary details here.

Drawings

In order to more clearly illustrate the embodiments of the present application, the drawings needed for the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is a schematic structural diagram of a pulsed electric field ablation system according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a pulsed electric field ablation system for reducing muscle twitches according to an embodiment of the present application;

FIG. 3 is a schematic diagram illustrating the blocking effect of high frequency stimulation provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of the blocking effect of low frequency stimulation;

FIG. 5 is a schematic diagram of the blocking effect of DC + high frequency different electrode input stimulation;

FIG. 6 is a schematic diagram of waveform parameter setting inputted by the same DC + high frequency electrodes;

FIG. 7 is a characteristic diagram of the blocking effect of the DC + high frequency same electrode input stimulation;

FIG. 8 is a schematic view of a straight ablation catheter configuration;

FIG. 9 is a schematic view of a ring ablation catheter configuration;

fig. 10 is a schematic view of a helical ablation catheter configuration.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a pulsed electric field ablation system according to an embodiment of the present application, where the pulsed electric field ablation system includes:

apulse ablation instrument 100, configured to perform a pulsed electric field ablation operation on a to-be-ablated region through an ablation catheter (also called a pulse ablation catheter) 101;

anelectrical stimulation apparatus 200 for electrically stimulating nerves at a target site through anelectrical stimulation catheter 201 so as to block local conduction of the nerves;

wherein the output current of theelectrical stimulation device 200 is smaller than the output current of thepulse ablator 100, and the target part is between the part to be ablated and the muscle twitch part. As a possible embodiment, the current range for pulsed electric field ablation operations is typically 1A to 10A; the output current range of the electrical stimulation is usually 1 mA-20 mA, so when the electrical stimulation device is used for electrically stimulating the target part, the muscle twitch of a patient is not caused.

The reason why the pulsed electric field ablation causes muscle twitching is that the instantaneous large current generated by the pulsed electric field ablation reaches peripheral nerves (such as phrenic nerves around the heart) of a part to be ablated, and the peripheral nerves are stimulated by the current output by the ablation, start to be excited autonomously after reaching an excitation threshold value and are transmitted to the abdomen and even four limbs through nerve fibers to finally form the systemic muscle twitching. To eliminate muscle twitches, it is necessary to temporarily block the down-transmission of phrenic neuron excitation. The muscle relaxants injected in the traditional solutions are in fact substances that antagonize the neurotransmitters required for the descent of the neural excitation. This example employs electrical stimulation of nerves involved in muscle twitching to arrest local conduction of the nerves.

The principle of blocking nerve local conduction by electrical stimulation is as follows: the neuroreflex has the characteristics of absolute refractory period and relative refractory period, i.e. it cannot respond/incompletely responds to another external stimulus within a period of time (usually 1-10ms) after one excitation, i.e. it cannot form a new excitation/form an excitation which is much weakened. The reason for this is that nerve signal conduction is blocked, and the mechanism can be divided into two major categories, complete block (absolute refractory period) formed by axon action potential conduction block and incomplete block (relative refractory period) formed by synaptic fatigue.

The mechanism for the rapid formation of axonal action potential block is as follows: in mammals, the concentration of sodium ions is far higher than that of potassium ions, the stimulation of a cathode electrode causes depolarization current to be generated on an axon stimulation area to form cathode block, a sodium ion channel is inactivated, or the stimulation of an anode electrode generates hyperpolarization current, but due to the current conservation, the depolarization current can be generated in a range of a few millimeters at two sides of the hyperpolarization current generation, so that virtual cathode block is formed. The retardation delay generation mechanism is that potassium ions flow from the inside of the membrane to the outside of the membrane after one stimulus, causing potassium ions to accumulate outside, to be lost inside, and this tendency is maintained for a long period of time. Due to long-term depolarization transitions of the membrane potential, the driving force for sodium ion influx is reduced, eventually resulting in complete block. The mechanism of formation of synaptic fatigue is based on the transient plasticity of neurons, a phenomenon of change in which the efficiency of synaptic transmission continues to increase or decrease, generally lasting from tens of milliseconds to several minutes. Repeated activation of the presynaptic membrane terminal during presynaptic membrane inhibition reduces neurotransmitter release in the synaptic cleft and thus fails to respond to high frequency triggers. During presynaptic membrane promotion, it is necessary to increase the concentration of calcium ions in the presynaptic membrane so that the amount of neurotransmitter release increases in response to the high frequency trigger. For the postsynaptic membrane, receptors on the postsynaptic membrane transition to a desensitized state during massive neurotransmitter exposure and are unresponsive to subsequent stimulation; at the same time, the neurotransmitter repeatedly activates receptors on the postsynaptic membrane to saturate it, which makes fewer receptors available for the neurotransmitter to bind in subsequent stimuli, resulting in a decrease in synaptic response amplitude. In addition, the transmission of neuronal excitation depends on the delivery of components such as neurotransmitters, which are stored in a limited amount and require a certain time (usually several minutes) for the human body to replenish them. High frequency stimulation can transiently deplete neurotransmitters, and the external stimulation frequency required to induce synaptic fatigue is approximately in the range of 0.1Hz-1kHz, with higher frequencies accelerating the depletion process. Thus, by applying an external stimulus, which consumes the neurotransmitter reserve in the local nerve for a short period of time, a window period can be created in which the neural signal cannot be transmitted.

When the nerve at the target site is electrically stimulated, the synaptic fatigue is usually triggered to form an incomplete block, and then a complete block mechanism is triggered. The higher the frequency of the electrical signal, the faster the complete block mechanism is triggered.

The pulsed electric field ablation system provided by the embodiment comprises a pulsed ablation instrument and an electrical stimulation device, wherein the pulsed ablation instrument is used for performing pulsed electric field ablation operation on a part to be ablated, and muscle twitches can be caused due to the large current of the pulsed electric field ablation operation. The present embodiment electrically stimulates the target site between the site of ablation and the site of muscle twitch using an electrical stimulation device such that nerve conduction at the target site is blocked. The scheme can reduce the muscle twitch condition caused by the pulse electric field ablation operation by using the electrical stimulation equipment without performing general anesthesia and injecting muscle relaxant on a patient, and can reduce the muscle twitch caused by the pulse electric field ablation operation on the basis of improving the safety and efficiency of the operation.

As a further introduction to the corresponding embodiment of fig. 1, there is a communication link between the pulse ablator and the electrical stimulation device, based on which the timing of the pulsed electric field ablation operation and the electrical stimulation operation can be determined. Correspondingly, the pulse ablation instrument can perform pulse electric field ablation operation on the part to be ablated through the ablation catheter at a preset moment; wherein the preset time is later than or equal to the time of the electrical stimulation device for electrical stimulation.

As a further introduction to the corresponding embodiment of fig. 1, the pulsed electric field ablation system may further include a three-dimensional mapping navigation device, which may be connected with the pulsed ablator and/or the electrical stimulation apparatus. Specifically, when the three-dimensional mapping navigation device is connected with the pulse ablation instrument, the three-dimensional mapping navigation device can display the position of the ablation catheter; when the three-dimensional mapping navigation device is connected with the electrical stimulation equipment, the three-dimensional mapping navigation device is used for displaying the position of the electrical stimulation catheter.

As a further introduction to the corresponding embodiment of fig. 1, the electrical stimulation apparatus includes a stimulation signal controller and a stimulation signal generator; the stimulation signal controller is used for controlling the signal output sequence and the signal waveform of the stimulation signal generator; the stimulation signal generator is used for inputting an electrical stimulation signal to the electrical stimulation catheter according to a control instruction of the stimulation signal controller. The control command comprises a signal output sequence and a signal waveform.

The electrical stimulation device should be capable of delivering electrical stimulation signals on demand and provide an adjustment interface for adjusting the pattern, dosage, timing, etc. of the stimulation output. The electrical stimulation device may also have the basic functions of an intracardiac stimulation device such as defibrillation prevention, low leakage current, etc. The electrical stimulation device can communicate with the pulse ablator to synchronize stimulation timing and parameters. As a possible embodiment, a set of stimulation signal generators may be included in the electro-stimulation device. As another possible embodiment, the electrical stimulation apparatus may comprise two or more sets of stimulation signal generators, each generating a different stimulation signal, for example, a first set of stimulation signal generator generates an ac stimulation signal (e.g. a high-frequency ac stimulation signal with a frequency of 10-40 kHz), and a second set of stimulation signal generator generates a dc stimulation signal. Through the control module, the two sets of stimulation signal generators can output electrical stimulation signals simultaneously or sequentially.

The signal waveform of the electro-stimulation device may be a square wave, a sine wave or a triangle wave. The blocking threshold of the square wave is the lowest, the blocking threshold of the sine wave is the next highest, and the blocking threshold of the triangular wave is the highest, but the blocking effects of the square wave and the sine wave are not obviously different. In addition, the square wave generates burrs in the actual output process, and in order to avoid unexpected interference caused by the burrs in the stimulation process, nerve block can be interrupted, or crosstalk occurs in a direct current and high frequency combined blocking mode. Therefore, the electrical stimulation signal may be a sine wave, that is: the alternating current stimulation signal generator is used for generating an alternating current stimulation signal with a sine wave shape. For other signal characteristics, there may be differences in the waveforms because of the blocking pattern.

Further, the stimulation signal generator may include a direct current stimulation signal generator and an alternating current stimulation signal generator. The electrical stimulation catheter comprises a plurality of electrodes; the electrical stimulation equipment is further used for selecting an electrode closest to the target part as a target electrode so as to output the same electrical stimulation signal through the target electrode at the same time to electrically stimulate the nerve of the target part. The same electrode can be used to output the DC stimulation signal and the AC stimulation signal in the above way. Specifically, the process of controlling the direct current stimulation signal generator and the alternating current stimulation signal generator by the stimulation signal controller to input the electrical stimulation signal to the target electrode of the electrical stimulation catheter includes: controlling the direct current stimulation signal generator to input continuously increased cathodal electrical stimulation signals; when the target part forms a direct current block, controlling the alternating current stimulation signal generator to input an alternating current stimulation signal, and controlling the direct current stimulation signal generator to keep the input cathodal electrical stimulation signal unchanged within a preset time period; and controlling the direct current stimulation signal generator to reduce the input cathode electrical stimulation signal so that the direct current stimulation signal generator inputs an anode electrical stimulation signal according to a preset rule until the anode electrical stimulation signal and the cathode electrical stimulation signal reach charge balance.

In addition, in this embodiment, different electrodes may be used to output the direct current stimulation signal and the alternating current stimulation signal, the electrical stimulation catheter includes a plurality of electrodes, and the electrical stimulation device is further configured to select 2 electrodes closest to the target site as a direct current discharge electrode and an alternating current discharge electrode, so that the direct current stimulation signal is output through the direct current discharge electrode to electrically stimulate the nerve of the target site, and the alternating current stimulation signal is output through the alternating current discharge electrode to electrically stimulate the nerve of the target site.

The flow described in the above embodiment is explained below by an embodiment in practical use.

Atrial fibrillation is a rapid arrhythmia, and the incidence rate of atrial fibrillation increases with age, and reaches 10% in people over 75 years old. The atrial excitation frequency during atrial fibrillation reaches 300-600 times/minute, the ventricular rate is often fast and irregular and sometimes can reach 100-160 times/minute, the heartbeat is much faster than that of a normal person, the heart beat is absolutely irregular, and the atrium loses effective contraction function. The incidence of atrial fibrillation is also closely related to coronary heart disease, hypertension, heart failure and other diseases.

The treatment modalities of atrial fibrillation include drug therapy and non-drug therapy, and drug therapy can be classified into sodium channel blockers, beta receptor antagonists, action potential duration-extending agents, and calcium channel blockers according to the mechanism of action. Although drug therapy is generally the preferred treatment option, it controls heart rhythm only to a certain extent, requires long-term administration, and is associated with side effects. For arrhythmia patients who cannot be controlled by drugs, non-drug treatment modes such as catheter ablation, pacemaker implantation, surgical intervention and the like can help patients to carry out heart rhythm control to improve symptoms. Catheter ablation, a branch of cardiovascular intervention, is a common procedure: the diagnosis and mapping catheter is inserted into a heart cavity through femoral vein puncture, an ablation target point is searched and treated, the catheter is withdrawn from the body after treatment (the duration is usually 1-3 hours), and hemostasis treatment is carried out on a puncture part. Compared with drug therapy, implantation therapy and surgical intervention, the catheter ablation operation has the advantages of quick effect, small wound, low subsequent risk (no implant) and the like.

Pulmonary vein electrical isolation is a recognized strategy for catheter ablation atrial fibrillation treatment. The operator would insert an ablation catheter into the left atrium to perform annular ablation of the myocardium at the ostium/vestibular region of the pulmonary vein. Conventional surgery uses a straight catheter with a single ablation electrode for point-to-point ablation. In this mode, only the tip electrode of the ablation catheter can output ablation energy, and the other electrodes on the catheter body can only be used for recording intracardiac electrical signals. However, this type of ablation is inefficient, time consuming, and prone to discontinuities between ablation points. Aiming at the problem, the multi-electrode ablation catheter can output energy simultaneously in the field, so that the myocardium can be ablated for one circle, and the continuity of treatment ablation and injury is improved.

In addition, the existing catheter ablation technology (radio frequency, freezing and the like) has no tissue selectivity, so that the myocardial ablation and the related tissues such as the phrenic nerve and the esophagus which are close to the heart can be affected, and serious complications such as phrenic nerve paralysis and esophageal fistula can be caused. Wherein the fatality rate of the esophageal fistula is as high as 50-60%. Surgeons are often forced to use lower energy for ablation due to the aforementioned complications. This is also a potential factor in the recurrence of atrial fibrillation, which leads to incomplete ablation. Unlike radio frequency or cryoablation techniques, the pulsed electric field technique of this project functions on the principle: a short-transient, high-intensity applied electric field is applied to the myocardial cells to tear the phospholipid double layer of the cell membrane and form irreversible pores (i.e., irreversible electroporation). The irreversible pores can cause the mixing of intracellular and extracellular fluids, and further induce apoptosis or necrosis of cells. Since the single discharge time of the pulsed electric field technique is extremely short (1-10ms), it is not enough to cause significant temperature changes (i.e., thermal damage) to the myocardial tissue. On the other hand, the electric field strength required to promote irreversible electroporation of different tissues also varies significantly. Specifically, an electric field strength of 400V/cm is sufficient to cause irreversible damage to the myocardium, whereas to damage vascular smooth muscle, electric field strengths of at least 1750V/cm and 3800V/cm are required for each nerve. Therefore, by reasonably controlling the electrode configuration of the catheter and the output electric field intensity, the related tissues such as blood vessels and nerves can be preserved while the cardiac muscle is selectively ablated.

In the case where conventional pulsed electric field ablation causes a patient to experience a whole body muscle twitch, the present embodiment is directed to a scheme for reducing or eliminating the muscle twitch induced by pulsed electric field ablation by applying external nerve stimulation.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a pulsed electric field ablation system for reducing muscle twitches according to an embodiment of the present application, the system including: the device comprises an electric stimulation catheter, an electric stimulation device, a pulse ablation catheter, a pulse ablation instrument and a communication end. RPN (Right Phrenic nerve) represents the right Phrenic nerve, SVC (superior Vena Cava) represents the superior Vena cava, RAA (Right Atrial application) represents the right auricle, IVC (Imperior Vena Cava) represents the inferior Vena cava, HV + (High Voltage +) represents the High Voltage output anode, and HV- (High Voltage-) represents the High Voltage output cathode. The pulse ablation instrument comprises a power socket, a high-voltage power supply, a pulse generating circuit, an output electrode switching array, an ammeter, a voltmeter, a pulse controller and an ablation energy output end. The electrical stimulation device comprises a stimulation signal controller, a stimulation signal generator 1, a stimulation signal generator 2, a power supply port and a stimulation signal output end.

The electrical stimulation catheter is connected with the electrical stimulation device and conducts the stimulation signals output by the electrical stimulation device to the vicinity of the nerve to be blocked. In this embodiment, the electrical stimulation catheter is placed within the heart chamber at a location near the phrenic nerve and downstream of nerve conduction from the pulse ablation site. The pulse ablation catheter is connected with a pulse ablation instrument and transmits an output signal of the pulse ablation instrument to an ablated object, namely, a tissue to be treated. The pulse ablation catheter can also return recorded information such as intracardiac potential, electrode contact impedance, head end pressure value and the like to the pulse ablation instrument to assist in smooth treatment. The pulse ablation instrument and the electrical stimulation equipment can be communicated with each other, so that the timing synchronization of electrical stimulation and the sending of pulse ablation signals is realized. The pulse ablator and/or the electrostimulation device can be further connected with a three-dimensional mapping navigation system, and the position of the pulse ablation catheter and/or the electrostimulation catheter and the associated information in treatment are displayed on the interface of the navigation system.

In this embodiment, the electrical stimulation catheter is not limited, and the tip of the electrical stimulation catheter is provided with at least one stimulation electrode. The stimulating electrode may deliver a stimulating current between the back plate (monopolar) or between two stimulating electrodes (bipolar). To reduce the stimulation energy, bipolar stimulation electrodes may be chosen.

The tip morphology of the electrical stimulation catheter may be: linear, curved, circular, spiral, etc. When the shape of the electric stimulation catheter is annular or spiral, an operator can more conveniently place the electric stimulation catheter in the inferior vena cava or the superior vena cava. The right phrenic nerve runs roughly parallel to the superior vena cava and the inferior vena cava of a human body, and the far end of the superior/inferior vena cava is not provided with a myocardial sleeve, so that the right phrenic nerve is the optimal position for carrying out nerve block. When the head end of the electric stimulation catheter is in a ring shape or a spiral shape, the diameter of the head end of the electric stimulation catheter is slightly larger than or equal to the inner diameter of the superior vena cava/inferior vena cava of a patient, the head end of the electric stimulation catheter can be stably attached to the superior vena cava/inferior vena cava. When the annular or spiral front end of the electrical stimulation catheter is provided with a plurality of electrodes (for example, more than 4), an operator can firstly find out the electrode pair which is anatomically closest to the phrenic nerve by means of nerve pacing and the like, and then sends out a nerve blocking signal from the electrode pair. In other embodiments, the electrical stimulation catheter is in the form of a circular arc having a circumference of 1/3-2/3 and a radius of curvature that is equal to or slightly greater than the superior/inferior vena cava radius. Such a catheter can achieve a good fit to the inside of the vein while not interfering with the operation of other catheters that enter the heart cavity via the inferior vena cava. When the arc-shaped electric stimulation catheter covers a range without the phrenic nerve, the electrode can be close to the phrenic nerve by rotating the position of the catheter.

The electro-stimulation device may output the electro-stimulation signal in at least three modes:

mode 1: high frequency stimulation mode

The high frequency stimulation frequency is typically in the range of 1kHz to 50kHz and the amplitude is typically no more than 10mA or 10V. For high-frequency stimulation, the basic characteristics are shown in fig. 3, fig. 3 is a schematic diagram of the blocking effect of high-frequency stimulation provided by the embodiment of the present application, an upper curve of fig. 3 is a variation curve of a muscle contraction extension force signal, force (n) represents muscle contraction extension force, time(s) represents time, a lower line of fig. 3 is a high-frequency stimulation signal, voltage (v) represents stimulation signal voltage, and time(s) represents time.

High frequency stimulation signals (sine wave, frequency 10-40kHz, amplitude 2-10.5V) stimulate the median nerve fibers, wherein the proximal stimulation (monophasic square wave, pulse width 50-300 mus, 1Hz, 2.0mA) induces the flexor muscles of the fingers to produce tension. The high-frequency stimulation signal is an alternating current stimulation signal. Initially, at times 0-3s, the nerve is stimulated at low frequency proximally and induces distal flexor twitches, the ordinate of which is the tension at which the muscle twitches. At 3s, the high frequency stimulation started the intervention and the nerves initiated a response. The initial response is usually accompanied by severe muscle twitches, which may cause pain. The initial reaction has three indicators of evaluation, peak force, decay time, and initial reaction integral. The peak force is the maximum tension induced by the muscle twitch during the initial response, the decay time is the time taken for the tension of the muscle twitch induced by the initial response to decay by 5% of the tension of the muscle twitch induced by the proximal stimulation, and the initial response integral is the integral of the tension of the muscle twitch during the initial response over time. The initial reaction is usually divided into two phases, stage one being the initial phase of peak force production, which is usually accompanied by strong muscle twitches; stage two is after stage one to full or partial blocking during which the tensile force continues to decay. The initial response is related to the stimulation frequency and amplitude, and also to the electrode settings. In which, no matter how to adjust the stimulation waveform parameters and the electrode settings, the initial reaction stage one will exist, but the stage two can greatly shorten the duration time and even eliminate it. Generally, when the stimulation frequency exceeds 100Hz, the frequency increases, the peak force decreases, and the decay time decreases. In addition, when the high frequency stimulus is removed, a response similar to the initial response is triggered, but which causes muscle twitches that are much smaller than the initial response. After removal of the high frequency stimulation, the recovery time is affected by the stimulation duration. The stimulation time is usually less than 15 minutes, and the pre-stimulation level can be recovered within 1 second; the stimulation time is longer than 15 minutes, and the recovery can be realized within 3 minutes; the stimulation period exceeded 40 minutes and recovery was slow, perhaps up to 2 hours. The high-frequency stimulation mode is characterized in that: the nerve block has the advantages of quick response, safety, stability, quick short-term stimulation recovery, complete block for different types of nerves, severe muscle twitch caused by initial reaction, and pain feeling.

Mode 2: low frequency stimulation mode

The low frequency stimulation frequency range is lower than 100Hz, the ultralow frequency stimulation frequency is lower than 0.1Hz, the waveform can be a square wave or a peak clipping sine wave, and the amplitude is usually not more than 1.5 mA. For low-frequency or ultra-low-frequency stimulation, the basic characteristics are shown in fig. 4, fig. 4 is a schematic diagram of the blocking effect of the low-frequency stimulation, Spikes/s in the upper part of fig. 4 represents the number of peaks of the nerve signal emitted by the autonomic nerve fibers per second, and the line in the lower part of fig. 4 represents the low-frequency stimulation signal. Fig. 4 shows that an ultra-low frequency stimulation signal (a peak clipping sine wave with a frequency less than 0.1Hz and an amplitude of 1.2mA) stimulates two spontaneous nerve fibers with a pulse spike of 5Hz before the intervention of low frequency stimulation. When the low frequency stimulus intervenes, conduction is blocked at the cathodic and anodic peaks, while at the switching phase, signal conduction occurs. As the stimulation time is extended, the signal conduction at the time of phase inversion disappears, and complete block is achieved. When the low frequency stimulus is removed, the block remains for a period of time, and then the spontaneous nerve fiber signaling begins to recover, and after a few minutes it is completely recovered.

The low-frequency stimulation mode has the characteristics of no initial response, safety, no pain, capability of serving as a treatment means for relieving pain, long stimulation duration, relatively slow response and recovery and obvious difference on different types of fiber blocking effects. Complete retardation is easier to realize for large diameter fibers, and complete retardation is not easy to realize for C-type fibers.

Mode 3: DC + high frequency stimulation mode

Since the high frequency stimulation induces an initial response, the initial response induced by the high frequency stimulation can be cancelled when the direct current stimulation is introduced. The DC + high frequency combined stimulation mode can be divided into two modes, wherein one mode is that DC + high frequency stimulation input is completed by different electrodes, and the other mode is that DC + high frequency stimulation input is completed by the same electrode.

The basic characteristics of the direct current + high frequency stimulation mode input by different electrodes are shown in fig. 5, fig. 5 is a schematic diagram of stimulation blocking effects of direct current + high frequency different electrode input, force (N) in fig. 5 represents muscle contraction stretching force, high frequency stimulation represents high frequency alternating current stimulation signals, direct current represents direct current stimulation signals, plateau represents an anode alternating current peak value, and plateau represents a cathode direct current peak value, and the absolute values of the two are equal. When the stimulation is started, cathode direct current with continuously increased current intensity is introduced to cancel the initial reaction induced by the direct current. Subsequently, the current intensity is increased to the DC peak value and kept constant, and meanwhile, the high-frequency AC stimulation intervenes, the initial reaction induced by the high-frequency stimulation is eliminated, and the continuous nerve conduction block is realized. Then the direct current intensity continuously decreases, the current intensity increases after the phase (current direction) is switched, and the nerve block is prevented from being interrupted by too high intensity. The current intensity then remains constant, continuing until the charge input by the cathode current is balanced. The high frequency signal is described above as a high frequency stimulus, in which case the time for the initial response induced by the high frequency signal can be shortened as much as possible, typically within 5s (higher frequency implementation is required, 20kHz, with an amplitude of 1.25 times the 20kHz blocking threshold amplitude). The direct current signal needs to ensure charge balance to ensure the nerve safety, and the cathode direct current intensity absolute value needs to reach a high-frequency alternating current intensity absolute value when the cathode current input time is too long (the cathode direct current stimulation time can be prolonged by using an electrode with higher capacitance). The subject of fig. 5 is the sciatic nerve connected to the gastrocnemius muscle, and when the sciatic nerve is stimulated by an electrical signal, the signal is transmitted to the gastrocnemius muscle, causing the gastrocnemius muscle to contract and generate a stretching force. The ordinate is the tensile force of the gastrocnemius muscle. The 1Hz electric signal is always kept to stimulate the nerve at the end of the sciatic nerve far away from the gastrocnemius muscle, so that the force of gastrocnemius muscle contraction is obtained. With the intervention of direct current and high frequency alternating current signals, the stretching force generated by the contraction of gastrocnemius muscles is reduced and even disappears because nerve conduction is completely blocked. The waveform characteristics of the direct current + high frequency input by the same electrode are shown in fig. 6, fig. 6 is a schematic diagram of the waveform parameter setting of the direct current + high frequency input by the same electrode, current (ma) in fig. 6 represents current, direct current represents a direct current stimulation signal, direct current + high frequency represents a direct current carrier and high frequency alternating current combined stimulation signal, and the first, second, … … and sixth represent stages. The continuously increased cathode current is input in the first stage, and the initial reaction induced by the direct current is eliminated. And after the current intensity is increased to the intensity required by the high-frequency alternating current block, the second stage is carried out, the direct current signal intensity is maintained, and the high-frequency alternating current signal intervenes to eliminate the initial reaction induced by the high-frequency stimulation. Subsequently, in a third phase, the absolute value of the current intensity decreases. In the fourth stage, the current phase change is that the anode current is gradually increased, and the intensity is not suitable to be too high. Then, in the fifth stage, the current intensity is kept constant to balance the charge of the cathode current input. In the sixth stage, after the charge tends to be balanced, the anode current decreases and tends to zero.

The basic characteristics of the above-mentioned stimulation blocking effect are shown in fig. 7, and fig. 7 is a characteristic diagram of the stimulation blocking effect inputted by the same electrode with direct current and high frequency. The upper line of fig. 7 is the muscle contraction stretching force signal generated by the muscle twitch induced after nerve stimulation, and the lower line is the direct current high frequency combined stimulation signal. In fig. 7, the cathodic current intensity is gradually increased, the cathodic direct-current stimulation time is increased, and the current intensity is rapidly increased before the intervention of the high-frequency stimulation, so that the initial responses respectively induced by the direct-current stimulation and the high-frequency stimulation are almost completely eliminated.

The ablation catheter of the embodiment comprises an ablation electrode, an electric wire, an electrode end tube, a catheter tube body, a handle and a connecting cable. The ablation electrode is fixed on the outer wall of the electrode end tube, the proximal end of the electrode end tube is connected with the distal end of the catheter body, and the proximal end of the catheter body is connected into the handle. The handle comprises a mechanical structure for controlling the radial size and the bending shape of the head end of the catheter, and an electric connector or an electric cable connected with equipment is fixed at the tail end of the handle. The electric wire passes through the electrode end tube and is electrically connected with the inside of the ablation electrode, the connection part is insulated, and the electric wire finally enters the handle through the catheter tube body and is connected with the electric connector at the tail end of the handle.

In some embodiments, the electrode-tip tube is straight, with all of the electrodes aligned along the long axis of the electrode-tip tube. In some embodiments, the electrode tip tube is annular or spiral in shape, and all of the electrodes are arranged in a circumferential direction of the electrode tip tube. In some embodiments, the catheter may include a plurality of electrode tip tubes that, in a natural state, assume the shape of a basket, a bifurcation of radiation, or the like.

Referring to fig. 8, 9 and 10, fig. 8 is a structural schematic view of a straight ablation catheter, fig. 9 is a structural schematic view of a ring ablation catheter, and fig. 10 is a structural schematic view of a spiral ablation catheter. In fig. 8, a1 is the tip, a2 is the tube body, A3 is the handle, a4 is the connection cable, a5 is the photoelectric plug, a is the tip electrode length, D is the electrode spacing length, H is the straight electrode length, L is the catheter length, Φ is the catheter outer diameter. In fig. 9, B1 is an ablation electrode, B2 is an annular end tube, B3 is a positioning electrode on a catheter tube body, B4 is a catheter tube body, B5 is a handle, B6 is a connector, D is the diameter of an annular ablation catheter, H is the length of an annular electrode, D is the length of an electrode space, L is the length of a catheter, and θ is the diameter of the catheter. In fig. 10, C1 is an ablation electrode, C2 is a ring-shaped end tube, C3 is a positioning electrode on the catheter tube body, C4 is the catheter tube body, C5 is a handle, and C6 is a connector.

In this embodiment, a plurality of ablation electrodes can output pulsed electric field signals simultaneously, or optionally more than two of the ablation electrodes can be controlled according to the program of the device to output pulsed electric field signals. In some embodiments of the invention, a back plate may be added to contact the patient's body surface, and the electrodes of either conduit may communicate with the back plate.

The pulse ablation instrument comprises a high-voltage power supply, a pulse generator, a pulse controller, a pulse output switching array and a pressure detection module. The pressure detection module is responsible for analyzing pressure information from the catheter tip and transmitting the information to the pulse controller. The pulse controller determines the pulse sending time according to the preset judgment condition. The pulse ablation instrument canoutput 30 electrodes at the maximum and can output pulse ablation signals of more than 500V. The device may also include a user interface or may be associated with other external equipment, such as a three-dimensional location mapping system. The foregoing discharge determination condition may be set through a user interface or an external device.

In this example, the method of use of the nerve block is as follows:

the stimulation site of the neural stimulation described in the present invention should be located between the ablation site and the site of muscle twitch, and specifically should be located downstream of the neurons excited by the neural stimulation in the nerve conduction channel (downstream of the neurons excited by the pulsed electric field output) and upstream of the ganglia that control the muscle activity at the site of muscle twitch. Stimulation may be performed in vivo, intravascularly, or in vitro at a site proximal to a nerve. Stimulation may continue until the end of the procedure or a paragraph before the start of the pulse ablation; alternatively, the ablation pulse signal may be synchronized to end at the same time as the ablation pulse signal, slightly before the ablation pulse signal is delivered. The amplitude and energy of the stimulation signal should be moderate, so that the stimulation signal can not only cause nerve excitation, but also cannot cause obvious side effects such as temperature rise, electrochemical action and the like which can cause nerve injury at the stimulation part. In this embodiment, the output electrode or a portion of the output electrode of the electrical stimulation catheter should be placed immediately downstream of the phrenic nerve before pulse ablation; starting electrical stimulation, and starting pulse ablation after confirming that the phrenic nerve of the patient is captured by the electrical stimulation (for example, the abdomen enters a tetanic state); after the pulse ablation finishes the set treatment content, the electric stimulation is stopped. The part of the electrical stimulation can be placed at the part without the myocardial muscle sleeve, so that the condition that the electrical stimulation signal is transmitted into the heart to interfere the normal conduction of the electrical stimulation of the myocardium to cause unexpected arrhythmia is avoided.

The present embodiment solves the problem of muscle twitch by electrical nerve stimulation, a commonly used means in the field of cardiac electrophysiology. Avoid general anesthesia and/or injection of muscle relaxant to the patient, reduce the surgical risk and the medical burden.

The application also provides an electronic device, the electronic device is respectively connected with the pulse ablation instrument and the electrical stimulation device, the electronic device comprises a memory and a processor, a computer program is stored in the memory, and the steps realized when the processor calls the computer program in the memory comprise:

controlling the pulse ablation instrument to perform pulse electric field ablation operation on a part to be ablated through an ablation catheter;

controlling the electrical stimulation device to electrically stimulate nerves of the target site through an electrical stimulation catheter so as to block local conduction of the nerves;

wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

The pulsed electric field ablation system provided by the embodiment comprises a pulsed ablation instrument and an electrical stimulation device, wherein the pulsed ablation instrument is used for performing pulsed electric field ablation operation on a part to be ablated, and muscle twitches can be caused due to the large current of the pulsed electric field ablation operation. The present embodiment electrically stimulates the target site between the site to be ablated and the site of muscle twitch using an electrical stimulation device such that nerve conduction at the target site is blocked. The scheme can reduce the muscle twitch condition caused by the pulse electric field ablation operation by using the electrical stimulation equipment without performing general anesthesia and injecting muscle relaxant on a patient, and can reduce the muscle twitch caused by the pulse electric field ablation operation on the basis of improving the safety and efficiency of the operation.

Further, the control of the pulse ablation instrument to perform the pulse electric field ablation operation on the to-be-ablated part through the ablation catheter comprises:

performing pulsed electric field ablation operation on a part to be ablated through an ablation catheter at a preset moment; wherein the preset time is later than or equal to the time of the electrical stimulation device for electrical stimulation.

Further, the method also comprises the following steps: displaying the position of the ablation catheter by using the three-dimensional mapping navigation device;

and/or displaying the position of the electric stimulation catheter by using a three-dimensional mapping navigation device.

Further, the electrical stimulation device comprises a stimulation signal controller and a stimulation signal generator;

the stimulation signal controller is used for controlling the signal output sequence and the signal waveform of the stimulation signal generator;

the stimulation signal generator is used for inputting an electrical stimulation signal to the electrical stimulation catheter according to a control instruction of the stimulation signal controller.

Further, the stimulation signal generator comprises a direct current stimulation signal generator and an alternating current stimulation signal generator.

Further, the method also comprises the following steps:

and selecting the electrode closest to the target part as a target electrode so as to output the same electrical stimulation signal through the target electrode at the same time to electrically stimulate the nerve of the target part.

Further, the process of controlling the direct current stimulation signal generator and the alternating current stimulation signal generator to input the electrical stimulation signal to the target electrode of the electrical stimulation catheter comprises:

controlling the direct current stimulation signal generator to input continuously increased cathodal electrical stimulation signals;

when the target part forms a direct current block, controlling the alternating current stimulation signal generator to input an alternating current stimulation signal, and controlling the direct current stimulation signal generator to keep the input cathode electrical stimulation signal unchanged within a preset time period;

and controlling the direct current stimulation signal generator to reduce the input cathode electrical stimulation signal so that the direct current stimulation signal generator inputs an anode electrical stimulation signal according to a preset rule until the anode electrical stimulation signal and the cathode electrical stimulation signal reach charge balance.

Further, the method also comprises the following steps:

and selecting 2 electrodes closest to the target part as a direct current discharge electrode and an alternating current discharge electrode so as to output a direct current electrical stimulation signal through the direct current discharge electrode to electrically stimulate the nerve of the target part and output an alternating current electrical stimulation signal through the alternating current discharge electrode to electrically stimulate the nerve of the target part.

Further, the alternating current stimulation signal generator is used for generating an alternating current stimulation signal with a sine wave shape.

The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description. It should be noted that, for those skilled in the art, without departing from the principle of the present application, the present application can also make several improvements and modifications, and those improvements and modifications also fall into the protection scope of the claims of the present application.

It should also be noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Claims (10)

1. A pulsed electric field ablation system, comprising:

the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter;

the electrical stimulation device is used for electrically stimulating the nerve of the target part through the electrical stimulation catheter so as to block local conduction of the nerve;

wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

2. The pulsed electric field ablation system of claim 1, wherein there is a communication link between the pulse ablator and the electrical stimulation device;

the pulse ablation instrument is used for executing pulse electric field ablation operation on a part to be ablated through the ablation catheter at a preset moment; wherein the preset time is later than or equal to the time of the electrical stimulation device for electrical stimulation.

3. The pulsed electric field ablation system of claim 1, further comprising a three-dimensional mapping navigation device;

the three-dimensional mapping navigation device is connected with the pulse ablation instrument and is used for displaying the position of the ablation catheter;

and/or the three-dimensional mapping navigation device is connected with the electrical stimulation equipment, and the three-dimensional mapping navigation device is used for displaying the position of the electrical stimulation catheter.

4. The pulsed electric field ablation system of claim 1, wherein the electrical stimulation device comprises a stimulation signal controller and a stimulation signal generator;

the stimulation signal controller is used for controlling the signal output sequence and the signal waveform of the stimulation signal generator;

the stimulation signal generator is used for inputting an electrical stimulation signal to the electrical stimulation catheter according to a control instruction of the stimulation signal controller.

5. The pulsed electric field ablation system of claim 4, wherein the stimulation signal generator comprises a direct current stimulation signal generator and an alternating current stimulation signal generator.

6. The pulsed electric field ablation system of claim 5, wherein the electrical stimulation catheter includes a plurality of electrodes thereon;

the electrical stimulation equipment is further used for selecting an electrode closest to the target part as a target electrode so as to output the same electrical stimulation signal through the target electrode at the same time to electrically stimulate the nerve of the target part.

7. The pulsed electric field ablation system of claim 6, wherein the process of the stimulation signal controller controlling the direct current stimulation signal generator and the alternating current stimulation signal generator to input the electrical stimulation signal to the target electrode of the electrical stimulation catheter comprises:

controlling the direct current stimulation signal generator to input continuously increased cathodal electrical stimulation signals;

when the target part forms a direct current block, controlling the alternating current stimulation signal generator to input an alternating current stimulation signal, and controlling the direct current stimulation signal generator to keep the input cathodal electrical stimulation signal unchanged within a preset time period;

and controlling the direct-current stimulation signal generator to reduce the input cathode electrical stimulation signal so that the direct-current stimulation signal generator inputs an anode electrical stimulation signal according to a preset rule until the anode electrical stimulation signal and the cathode electrical stimulation signal reach charge balance.

8. The pulsed electric field ablation system of claim 5, wherein the electrical stimulation catheter includes a plurality of electrodes thereon;

the electrical stimulation equipment is also used for selecting 2 electrodes closest to the target part as a direct current discharge electrode and an alternating current discharge electrode so as to output a direct current electrical stimulation signal through the direct current discharge electrode to electrically stimulate the nerve of the target part and output an alternating current electrical stimulation signal through the alternating current discharge electrode to electrically stimulate the nerve of the target part.

9. The pulsed electric field ablation system of claim 4, wherein the AC stimulation signal generator is configured to generate an AC stimulation signal having a sine wave waveform.

10. An electronic device, wherein the electronic device is connected with a pulse ablator and an electrical stimulation device, respectively, the electronic device comprises a memory and a processor, the memory stores a computer program, and the processor calls the computer program in the memory to realize the steps of:

controlling the pulse ablation instrument to perform pulse electric field ablation operation on a part to be ablated through an ablation catheter;

controlling the electrical stimulation device to electrically stimulate nerves of the target site through an electrical stimulation catheter so as to block local conduction of the nerves;

wherein the output current of the electrical stimulation device is smaller than that of the pulse ablation instrument, and the target part is positioned between the part to be ablated and the muscle twitch part.

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