A cardiac wall thickness monitoring device

Abstract

The application provides a heart wall thickness monitoring device, which comprises a medical catheter in direct contact with a heart wall, an impedance measuring instrument and a computing processing device storing a calibration matrix, wherein the medical catheter is used for generating an electric signal and measuring a contact pressure value of the medical catheter in direct contact with the heart wall; the impedance measuring instrument is electrically connected with the medical catheter and is used for converting the electric signal into an impedance value; the computing processing device is electrically connected with the medical catheter and the impedance measuring instrument, receives the contact pressure value and the impedance value, and finds a data group closest to the contact pressure value and the impedance value in the calibration matrix, and the heart wall thickness in the data group is the monitored heart wall thickness. The application realizes the problem of low-cost real-time monitoring of the tissue thickness of a target ablation site in an ablation operation process, and based on the real-time monitored tissue thickness, the ablation energy and the ablation duration of the medical catheter in the ablation process can be determined, so that the operation safety and the ablation treatment effect are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical surgical instruments, in particular to a heart wall thickness monitoring device. BACKGROUND

[0002] Catheter radiofrequency ablation is the most commonly used minimally invasive intervention technique for treating arrhythmia. The cause of arrhythmia is that abnormal electrical signal transmission occurs in part of the heart tissue, which abnormally conducts the electrical signal of the heart to other adjacent tissues, thereby interrupting the normal heart cycle to cause arrhythmia. The basic principle of catheter radiofrequency ablation is that a radiofrequency medical catheter is sent to the target heart chamber through a catheter of different lengths, and under the guidance of three-dimensional mapping technology, the arrhythmia origin lesion is accurately positioned, the columnar ablation electrode at the head end of the catheter is contacted to the lesion tissue with effective contact pressure, and then radiofrequency current is emitted through the loop electrode attached to the patient's skin. The radiofrequency current flows through the lesion tissue under the electrode, and heat is generated in the tissue. When the temperature reaches the degree of coagulative necrosis, the tissue permanently loses electrophysiological activity, thereby cutting off the abnormal electrical signal transmission, restoring the normal heart cycle, and curing arrhythmia.

[0003] Currently, doctors cannot obtain the wall thickness of the target ablation site of the heart in advance when performing catheter radiofrequency ablation surgery on patients. Some parts of the heart with thin wall thickness are ablated, and when the operator controls the catheter to abut the columnar ablation electrode at the head end of the catheter against the target ablation site with effective contact pressure, it is easy to cause excessive force to cause heart perforation and other accidents, threatening the safety of the patient's surgery. When ablation is performed on the part of the patient's heart with thin wall thickness, if the ablation energy controlled by the operator is too large or the ablation time is too long, the target ablation site will be ablated excessively, causing local charring effect, coagulum or explosive steam burst, which endangers the patient's life. It may also cause the contraction of the part, affecting the normal beating of the heart. If the ablation site is near the blood vessel, it will cause the contraction of the blood vessel opening, causing insufficient blood supply to the human body and other surgical complications, affecting the quality of the surgery. When ablation is performed on the part of the patient's heart with thick wall thickness, if the ablation energy controlled by the operator is too small or the ablation time is too short, the part will not be ablated sufficiently, the side of the heart wall away from the head end of the medical catheter will not be ablated sufficiently, and the purpose of cutting off abnormal electrical signal transmission will not be achieved, affecting the quality of the surgery.

[0004] The prior art proposes a method of measuring tissue thickness using ultrasound measurements and force measurements, inserting a catheter having a distal section into a body of a subject and into contact with a wall of a heart chamber having an inner surface and an outer surface, the catheter distal section having a contact pressure sensor and an ultrasound transducer. The transducer is actuated to acquire ultrasound reflection data from the wall of the chamber, while the transducer is actuated, the catheter is reciprocated against the wall of the chamber and the contact pressure between the catheter and the wall of the chamber is measured, the reflection data is combined with the contact pressure, a set of reflection data having a highest correlation with the contact pressure is identified and a tissue thickness between the inner surface and the identified set of reflection data is determined from a time of flight between the inner surface and the identified set of reflection data.

[0005] In the above technical solution, the measurement is performed by an ultrasonic probe or the like, and such an instrument is often expensive, resulting in high surgical costs. SUMMARY

[0006] The present application aims to solve the problem of how to monitor the tissue thickness of the target ablation site in real time during the ablation procedure at a low cost. Meanwhile, based on the real-time monitored tissue thickness, the ablation energy and the ablation duration of the medical catheter during the ablation procedure are determined, and the contact pressure alarm threshold of the medical catheter and the target ablation site is set. After the above values are fed back to the operator through the display device, the operator can more accurately perform the ablation, thereby improving the safety of the operation and the ablation treatment effect.

[0007] The present application provides a heart wall thickness monitoring device, comprising a medical catheter in direct contact with a heart wall, an impedance measuring instrument and a computing processing device storing a calibration matrix. The medical catheter is in direct contact with the heart wall, used to generate an electrical signal and measure the contact pressure value of the medical catheter and the heart wall; the impedance measuring instrument is electrically connected with the medical catheter, used to convert the electrical signal into an impedance value; the computing processing device stores the calibration matrix, electrically connected with the medical catheter and the impedance measuring instrument, used to receive the contact pressure value and the impedance value, and find the data group closest to the contact pressure value and the impedance value in the calibration matrix, and the heart wall thickness in the data group is the monitored heart wall thickness.

[0008] According to the embodiment of the present application, the calibration matrix is generated by a calibration matrix generating device, which comprises a body environment simulation device, a simulation catheter, an impedance measuring instrument, a pressure measuring instrument, a motor control module and a computing processing device. The body environment simulation device comprises a cylinder, a deformation porous plate and a beaker. The cylinder stores first saline, and the bottom of the cylinder is provided with a grounding plate, and the grounding plate is provided with the deformation porous plate, and the experimental tissue is placed on the deformation porous plate for deformation with the experimental tissue. The beaker stores second saline, and the beaker is connected with the grounding plate through a catheter.

[0009] The simulation catheter has electrodes for generating a local electric field and forming an electric signal. The impedance measuring instrument is electrically connected with the simulation catheter, and converts the electric signal into an impedance value. The motor control module controls the simulation catheter to apply pressure to the experimental tissue. The pressure measuring instrument is used for measuring and displaying a contact pressure value of the applied pressure, and transmitting the contact pressure value to the computing processing device. The computing processing device is electrically connected with the impedance measuring instrument, the pressure measuring instrument and the motor control module, receives the contact pressure value, the impedance value, a type of the experimental tissue and a thickness value of the experimental tissue, and forms a calibration matrix.

[0010] According to the embodiment of the present application, the motor control module comprises a stepper motor, a control circuit electrically connected with the stepper motor and controlling the stepper motor to move, and a fixed rod fixedly connecting the stepper motor and the simulation catheter, so that the simulation catheter is parallel to the stepper motor and moves.

[0011] According to the embodiment of the present application, the generating device of the calibration matrix further comprises a circulating pump, which controls the temperature and flow speed of the first saline to simulate the human blood.

[0012] According to the embodiment of the present application, the medical catheter has electrodes, which comprise a first electrode and a second electrode. The first electrode is arranged at the head end of the medical catheter to generate a local electric field. The second electrode is adjacent to the first electrode to convert the local electric field into an electric signal.

[0013] According to the embodiment of the present application, the medical catheter has a pressure sensor for measuring a contact pressure value of the medical catheter and the heart wall.

[0014] According to the embodiment of the present application, the computing processing device comprises an ablation calculation module, which determines an ablation energy and an ablation time length based on the heart wall thickness monitored in real time.

[0015] According to the embodiment of the present application, the computing processing device comprises a pressure alarm module, which sets a pressure alarm threshold of the medical catheter and the target ablation site based on the heart wall thickness monitored, and sends an alarm when the pressure generated by the medical catheter on the target ablation site exceeds the pressure alarm threshold.

[0016] According to the embodiment of the present application, the medical catheter is an ablation catheter.

[0017] According to the embodiment of the present application, the heart wall thickness monitoring device further comprises an ablation generator electrically connected with the ablation catheter and providing the ablation catheter with an ablation energy.

[0018] Before ablation surgery, the operator cannot obtain the heart cavity wall thickness of the target ablation site of the patient, and cannot accurately control the ablation energy and ablation time sent by the medical catheter, and the traditional heart wall thickness measuring device is measured by sensors and ultrasonic probes and other tools, such that such instruments are often expensive and the cost of surgery is too high. The present application can measure the heart wall thickness by using a conventional pressure catheter, thereby reducing the cost of surgery. The present application sets a pressure alarm threshold, ablation energy and ablation time based on the tissue wall thickness, so that the surgical process is safer and more efficient. At the same time, the calibration matrix generation device provided by the present application establishes a calibration matrix of the contact pressure value and impedance value of the catheter and the target tissue of different tissue types and different tissue thicknesses. Through the calibration matrix, the computing processing device compares the contact pressure and impedance value of the medical catheter to the tissue during the ablation process with the data in the calibration matrix, and the wall thickness displayed by the closest set of data is the thickness of the tissue at the catheter contact site. No additional ultrasonic equipment is needed, which greatly reduces the cost of surgery. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of a heart wall thickness real-time monitoring device according to an embodiment of the present application;

[0020] Figure 2 It is a schematic diagram of local electric field distortion caused by movement of a medical catheter according to an embodiment of the present application;

[0021] Figure 3 It is a schematic diagram of a calibration matrix generation device according to an embodiment of the present application;

[0022] Figure 4 It is a schematic diagram of a simulated catheter applying pressure to experimental tissue according to an embodiment of the present application.

[0023] Reference signs

[0024] Medical catheter 110, first electrode 111, second electrode 112, pressure sensor 113, impedance measuring instrument 120, ablation generator 130, computing processing device 140, electrode patch 150,

[0025] Calibration matrix generation device 200,

[0026] Simulated catheter 210, third electrode 211, fourth electrode 212,

[0027] Cylinder 220, grounding plate 221, deformed porous plate 222, gasket 223, first saline 224,

[0028] Beaker 230, second saline 231,

[0029] Stepping motor 241, head 2411, rod 2412, motor control circuit 242, fixed rod 243,

[0030] Circulating pump 250,

[0031] Pressure measuring instrument 260,

[0032] Experimental tissue 300. DETAILED DESCRIPTION

[0033] In order to further illustrate the technical means and effects taken by the utility model to achieve the predetermined purpose and the effects, the utility model will be described in detail below in combination with the drawings and preferred embodiments as follows.

[0034] As Figure 1 shown, the heart wall thickness real-time monitoring device provided by the application comprises a medical catheter 110, an impedance measuring instrument 120 and a computing processing device 140.

[0035] The medical catheter 110 is in direct contact with the heart wall, is used for generating an electrical signal and measuring a contact pressure value of the medical catheter 110 in direct contact with the heart wall, and the impedance measuring instrument 120 is electrically connected with the medical catheter 110, converts the electrical signal into an impedance value. The impedance measuring instrument 120 comprises a conventional filter (a band-pass filter) to prevent signals of no interest from passing through, but allows signals of appropriate frequency such as an excitation frequency to pass through, and also comprises conventional signal processing software to obtain the impedance R of the measured signal.

[0036] The computing processing device 140 stores a calibration matrix, is electrically connected with the medical catheter 110 and the impedance measuring instrument 120, receives the contact pressure value and the impedance value, and finds a data group closest to the contact pressure value and the impedance value in the calibration matrix, and the heart wall thickness in the data group is the monitored heart wall thickness.

[0037] According to the embodiment of the application, the calibration matrix is generated by a calibration matrix generating device 200, and the calibration matrix generating device 200 comprises a body environment simulation device, a simulation catheter 210, an impedance measuring instrument 120, a pressure measuring instrument 260, a motor control module and a computing processing device 140.

[0038] The body environment simulation device comprises a cylinder 220, a deformation porous plate 222 and a beaker 230. The cylinder stores first saline 224, the bottom of the cylinder is provided with a grounding plate 221, the grounding plate 221 is provided with the deformation porous plate 222, the experimental tissue is placed on the deformation porous plate 222, and the deformation porous plate 222 is used for deforming with the experimental tissue. The beaker 230 stores second saline, and is connected with the grounding plate 221 through a wire. Specifically, as Figure 3As shown, the cylinder 220 contains a first saline 224 for simulating blood, and the bottom of the cylinder 220 is provided with a grounding plate 221 connected to a beaker 230 for acting as a series resistor through a wire, and the beaker 230 contains a second saline 231, the resistivity of the second saline 231 can be controlled by the liquid level in the beaker 230 and the salinity of the saline, so that the entire circuit has an impedance similar to that of the human body. The deformed porous plate 222 supported by the gasket 223 is provided on the grounding plate 221, and the experimental tissue 300 to be tested is placed on the deformed porous plate 222, and the deformed porous plate 222 can be deformed synchronously with the experimental tissue 300.

[0039] The simulation catheter 210 has electrodes for generating a local electric field and forming an electrical signal. The impedance measuring instrument 120 is electrically connected to the simulation catheter 210 to convert the electrical signal into an impedance value. The impedance measuring instrument 120 is connected to the beaker 230 to complete the current return path. As the simulation catheter 210 contacts the experimental tissue 300 and continuously applies pressure downward to make the experimental tissue 300 concave, the local electric field generated by the third electrode 211 of the simulation catheter 210 also changes, and the fourth electrode 212 of the simulation catheter 210 senses the change in the local electric field, and the impedance measuring instrument 120 converts the electrical signal obtained by the fourth electrode 212 into an impedance value, which changes with the change in the local electric field.

[0040] The motor control module controls the simulation catheter 210 to apply pressure to the experimental tissue.

[0041] The pressure measuring instrument 260 is used to measure and display the contact pressure value of the applied pressure, and transmit the contact pressure value to the computing processing device. Figure 3 In particular, the pressure measuring instrument 260 records and displays the contact pressure value, and the digital scale is in grams.

[0042] The computing processing device 140 is electrically connected to the impedance measuring instrument 120, the pressure measuring instrument 260, and the motor control module, receives the contact pressure value, the impedance value, the type of experimental tissue, and the thickness value of the experimental tissue, and forms a calibration matrix.

[0043] According to the embodiment of the present application, the motor control module comprises: a stepper motor 241; a motor control circuit 242 electrically connected to the stepper motor 241 and controlling the stepper motor 241 to move; and a fixed rod 243 fixedly connected to the stepper motor 241 and the simulation catheter 210, so that the simulation catheter 210 is parallel to and moves with the stepper motor 241. Figure 3As shown, the operator sends instructions to the computing processing device 140, the computing processing device 140 transmits the instructions to the motor control circuit 242, the motor control circuit 242 is connected with the stepping motor 241 through a cable, controls the up and down movement of the stepping motor 241, and the stepping motor 241 is connected with the simulation catheter 210 through the fixed rod 243, so as to control the simulation catheter 210 to move up and down in the millimeter range. The distance of the downward movement of the simulation catheter 210 is recorded by the stepping motor 241 control circuit and transmitted to the computing processing device 140.

[0044] The stepping motor 241 includes a head part 2411 and a rod part 2412, and the rod part 2412 is threadedly connected with an inner thread provided at one end of the fixed rod 243 through an outer thread. The motor control circuit 242 controls the operation of the stepping motor 241, the rod part 2412 of the stepping motor rotates, drives the fixed rod 243 threadedly connected with the rod part 2412 to move upward or downward as a whole, and the simulation catheter 210 also moves up and down.

[0045] The stepping motor 241 control circuit transmits the downward displacement ΔX of the simulation catheter 210 to the computing processing device 140 in mm unit every time the simulation catheter 210 moves downward. The computing processing device 140 also records and stores the contact pressure value F and the impedance value R transmitted by the impedance measuring instrument 120, and stores them into the calibration matrix. The simulation catheter 210 moves downward every time, and a corresponding set of displacement ΔX, impedance value R and force value F is obtained. The recorded information of each set of test is stored in the calibration matrix together with the known thickness of the experimental tissue 300. The operation is repeated for different types of experimental tissue 300 and different thicknesses of experimental tissue 300, and the force value and impedance value R are collected by the repeated operation, so as to form a calibration matrix composed of the type of experimental tissue 300, the thickness of experimental tissue 300, the displacement, the force value and the impedance value. Generally, the calibration matrix includes at least three elements of impedance value (displacement value), force value and corresponding tissue thickness value, and the value of each element can be stored in interval value when stored, for example, the values of the three elements can be stored in the form of {[a1, a2], [b1, b2], [c1, c2]} or in the form of {[a1, ±Δa0], [b1, ±Δb0], [c1, ±Δc0]} when stored in the calibration matrix.

[0046] As shown in Figure 4 The same force F is applied orthogonally to two experimental tissues 300 with different thicknesses, the thickness of the experimental tissue 300 with thinner wall thickness is t1, and the displacement ΔX1 is generated, the thickness of the experimental tissue 300 with thicker wall thickness is t2, and the displacement ΔX2 is generated, ΔX1>ΔX2, and the two different displacements will result in different impedance values.

[0047] The derivation of the displacement ΔX and impedance value generated by the medical catheter 110 against the target tissue is as follows. In the myocardium and blood, the distribution of current is not simple because of the relationship of the geometry and many materials (such as myocardium, blood, bone, and skin). This problem can be illustrated by a metal sphere with a radius of r1, which is surrounded by several other spherical shells, each of which represents a different material. The thickness of each shell is r1, and there are a total of N-1 shells. Therefore, the total resistance from the metal sphere to the outermost surface is given by Equation 1

[0048]

[0049] where p n is the resistivity of the nth ring. If p n are all equal to p, which means the same material, the above equation simplifies to Equation 2 ：

[0050]

[0051] Since the resistivity of blood is less than that of myocardium, when the medical catheter 110 penetrates the myocardium, the near potential field around the tip electrode is greatly distorted, and more areas of the tip electrode are surrounded by myocardium with higher resistivity. Because, when the tip electrode penetrates the target tissue, the impedance increases rapidly. Monitoring the impedance Z of the medical catheter 110 electrode can give a prediction of the displacement of the tip electrode into the target tissue. However, in order to predict the penetration of the medical catheter 110 in the target tissue, some assumptions can be made that the current flows through the ground rod to the ground, the above equation becomes Equation 3:

[0052]

[0053] x is the depth of penetration of the tip electrode, r c is the diameter of the tip electrode. The value of r c comes from the specification of the medical catheter 110.

[0054] From the above equation, the calculation relationship between the displacement ΔX and impedance generated by the medical catheter 110 against the target tissue can be derived, and the displacement ΔX generated by the medical catheter 110 against the target tissue is inversely proportional to the impedance value.

[0055] During the surgery, the surgeon can appropriately touch the target tissue using the medical catheter 110, and transmit the signal sensed by the second electrode 112 back to the impedance measuring instrument 120 to convert the signal into an impedance value. The force F applied by the medical catheter 110 to the target tissue can be directly measured by the pressure sensor 113 of the medical catheter 110. The calculation and processing device 140 can automatically match the obtained impedance value and the force F applied by the medical catheter 110 to the target tissue in the calibration matrix, and obtain the tissue thickness in the set of data that is closest to the impedance value and the force F applied by the medical catheter 110 to the target tissue. This tissue thickness is the thickness of the target tissue.

[0056] According to an embodiment of the present invention, the calibration matrix generation device 200 further includes a circulation pump 250, which controls the temperature and flow rate of the first saline solution 224 to simulate human blood.

[0057] According to an embodiment of the present invention, a medical catheter has electrodes, including a first electrode 111 and a second electrode 112. The first electrode 111 is disposed at the tip of the medical catheter and generates a local electric field; the second electrode 112 is adjacent to the first electrode 111 and converts the local electric field into an electrical signal. As the medical catheter 110 approaches and presses against the target tissue with a certain contact pressure, due to the different resistivity of blood and target tissue, the local electric field generated by the first electrode 111 at the tip of the medical catheter 110 changes with the movement of the medical catheter 110. The local electric field is distorted due to the contact between the medical catheter 110 and the high resistivity myocardium, such as... Figure 2 As shown, when the medical catheter 110 is not in contact with the target tissue, the local electric field is E1; when the medical catheter 110 contacts the target tissue, the local electric field is E2. The second electrode 112 senses the above-mentioned electric field change and transmits it back to the computing and processing device 140, while the impedance measuring instrument 120 converts the sensed electrical signal into impedance and sends the impedance to the computing and processing device 140.

[0058] According to an embodiment of the present invention, the medical catheter 110 has a pressure sensor 113 for measuring the contact pressure value between the medical catheter 110 and the heart wall.

[0059] According to an embodiment of the present invention, the computational processing device includes an ablation calculation module that determines the ablation energy and ablation duration based on the monitored cardiac wall thickness. The ablation calculation module automatically generates the required ablation energy and duration for each location based on the wall thickness. For locations with thicker cardiac walls, the ablation energy is increased, and a longer ablation time is provided; for locations with thinner cardiac walls, the ablation energy is decreased, and the ablation time is shortened to prevent over-ablation leading to tissue contraction and surgical complications, or insufficient ablation affecting the surgical outcome. After the ablation time and intensity are displayed on the display system, the surgeon can perform ablation more precisely, thereby improving surgical safety and the effectiveness of the ablation treatment.

[0060] The difficulty in using RF energy to ablate target tissue is to control the local heating of the target tissue, which requires a trade-off between forming a large enough ablation lesion to effectively ablate the abnormal target tissue focus or block the abnormal conduction pattern and the adverse effects of excessive local heating: if the RF device forms too small an ablation lesion, the treatment process can be less effective, or can take a long time to cut off the transmission of abnormal electrical signals, if the target tissue is overheated, it can cause local carbonization effects, coagulum or explosive steam burst; if the RF device forms too large an ablation lesion, it can inadvertently ablate adjacent target tissue, and in some cases, a perforation of the heart wall can occur. The present application is based on the determination of the ablation energy and the ablation time based on the real-time monitored heart wall thickness value to achieve the purpose of both sufficient ablation to cut off the transmission of abnormal electrical signals and not to ablate too much to cause the site to contract and affect the normal function of the heart.

[0061] According to an embodiment of the present application, the computing processing device 140 comprises a pressure alarm module, which sets a pressure alarm threshold for the medical catheter 110 and the target ablation site based on the monitored heart wall thickness value. When the pressure generated by the medical catheter 110 on the target ablation site exceeds the pressure alarm threshold, the computing processing device 140 issues an alarm. The pressure alarm module sets different pressure alarm thresholds based on different wall thicknesses, and sets a lower pressure alarm threshold when the heart wall is thinner, and sets a higher pressure alarm threshold when the heart wall is thicker, so that the operator can apply a larger contact pressure against the heart cavity wall at the thicker part of the heart cavity wall for sufficient ablation, and when the pressure generated by the catheter on the heart exceeds the pressure alarm threshold at this part, the system will issue an alarm to prompt the operator that the pressure is too large, effectively controlling the risk of the operation and preventing heart perforation.

[0062] Specifically, as Figure 1As shown, in the ablation process, the electrode patch 150 attached on the body acts as a ground wire to complete the current reflux of the system, the signal generator generates a low amplitude signal to stimulate the first electrode 111 at the head end of the medical catheter 110, thereby generating a local electric field at the head end of the medical catheter 110, the second electrode 112 is used to sense the local electric field generated by the first electrode 111 and transmit the sensed electric signal to the impedance measuring instrument 120 through the appropriate wire, and convert the electric signal sensed by the second electrode 112 into an impedance value, which is transmitted to the computing processing device 140 through the wire, the computing processing device 140 includes an electronic control unit, a CPU (central processing unit) and a display system, wherein the CPU compares the impedance value input from the impedance measuring instrument 120, the contact pressure value obtained from the pressure sensor 113 with the calibration matrix stored in the CPU, and the tissue wall thickness in the group of data closest to the above-mentioned obtained contact pressure value and impedance value in the calibration matrix is the wall thickness value closest to the target tissue contacted by the medical catheter 110, and the CPU finally stores the data in the internal memory and transmits it to the display system, and the operator obtains the wall thickness value of the target tissue at the catheter abutting part from the display system.

[0063] According to the embodiment of the present application, the medical catheter 110 of the present application is an ablation catheter. In the ablation process, the ablation operation is directly performed without replacing the catheter, making the operation process more simple.

[0064] According to the embodiment of the present application, the real-time cardiac wall thickness monitoring device of the present application further comprises an ablation generator 130 electrically connected with the ablation catheter to provide ablation energy for the ablation catheter. The ablation generator 130 can provide ablation energy for the first electrode 111 at the head end of the catheter, and in the ablation process, the ablation operation is directly performed without replacing the catheter, making the operation process more simple.

[0065] Through the description of the specific embodiments, the technical means and effects taken by the present application to achieve the predetermined purposes can be more deeply and specifically understood, however, the accompanying drawings are only provided for reference and illustration, and are not used to limit the present application.

Claims

1. A cardiac wall thickness monitoring device, characterized by, The medical catheter is in direct contact with the heart wall for generating an electrical signal and measuring a contact pressure value of the medical catheter in direct contact with the heart wall. The impedance measuring instrument is electrically connected with the medical catheter and converts the electrical signal into an impedance value. The computing processing device stores a calibration matrix, is electrically connected with the medical catheter and the impedance measuring instrument, receives the contact pressure value and the impedance value, and finds a data group closest to the contact pressure value and the impedance value in the calibration matrix, and the heart wall thickness in the data group is the monitored heart wall thickness. The calibration matrix is generated by a calibration matrix generating device, and the calibration matrix generating device comprises: A body environment simulation device comprising a cylinder, a deformation porous plate and a beaker, The cylinder is used for storing first saline, and the bottom of the cylinder is provided with a grounding plate, and the deformation porous plate is arranged on the grounding plate, The experimental tissue is placed on the deformation porous plate for deformation with the experimental tissue, The beaker stores second saline, and the beaker is connected with the grounding plate through a wire; The simulation catheter has an electrode for generating a local electric field and forming an electrical signal; The impedance measuring instrument is electrically connected with the simulation catheter and converts the electrical signal into an impedance value; The motor control module controls the simulation catheter to apply pressure to the experimental tissue; The pressure measuring instrument is used for measuring and displaying the contact pressure value of the applied pressure and transmitting the contact pressure value to the computing processing device; The computing processing device is electrically connected with the impedance measuring instrument, the pressure measuring instrument and the motor control module, receives the contact pressure value, the impedance value, the type of experimental tissue and the thickness value of experimental tissue, and forms a calibration matrix. The motor control module comprises:

2. The cardiac wall thickness monitoring apparatus of claim 1, wherein, A stepping motor; A control circuit electrically connected with the stepping motor and controlling the movement of the stepping motor; A fixed rod fixedly connecting the stepping motor and the simulation catheter, so that the simulation catheter is parallel to the stepping motor and moves. The calibration matrix generating device further comprises a circulating pump for controlling the temperature and flow speed of the first saline to simulate human blood.

3. The cardiac wall thickness monitoring apparatus of claim 1, wherein, The medical catheter has an electrode comprising a first electrode and a second electrode, the first electrode is arranged at the head end of the medical catheter for generating a local electric field, and the second electrode is adjacent to the first electrode for converting the local electric field into the electrical signal.

4. The cardiac wall thickness monitoring apparatus of claim 1, wherein, The medical catheter has a pressure sensor for measuring the contact pressure value of the medical catheter and the heart wall.

5. The cardiac wall thickness monitoring apparatus of claim 1, wherein, The computing processing device comprises an ablation calculation module for determining ablation energy and ablation time based on the monitored heart wall thickness.

6. The cardiac wall thickness monitoring apparatus of claim 1, wherein, The computing processing device comprises a pressure alarm module for determining a pressure alarm threshold of the medical catheter and a target ablation site based on the monitored heart wall thickness value, and the computing processing device issues an alarm when the pressure generated by the medical catheter on the target ablation site exceeds the pressure alarm threshold.

7. The cardiac wall thickness monitoring apparatus of claim 1, wherein, The medical catheter is an ablation catheter.

8. The cardiac wall thickness monitoring apparatus of any one of claims 1-7, wherein, ​ 9. The cardiac wall thickness monitoring apparatus of claim 8 wherein, The cardiac wall thickness monitoring device further comprises an ablation generator electrically connected with the ablation catheter for providing ablation energy to the ablation catheter.

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