Heart mesh with electrodes

Abstract

The effect of pacing applied to the ventricles is improved in an electrode-carrying heart net. The electrode-carrying heart net (100) is formed by connecting a non-conductive portion (101, 103, 105, 107) formed by braiding non-conductive or conductive silk threads, a defibrillation electrode (102, 108) and a pacing electrode (104, 106). The defibrillation electrodes (102, 108) are electrodes used for defibrillation, and are formed in a manner that roughly horizontally covers the periphery of the heart and are arranged up and down. The pacing electrodes (104, 106) are electrodes used for sensing the work of the heart and pacing the ventricles, and are formed in a manner that roughly horizontally covers the periphery of the heart and covers the center of the spiral entry and are arranged between the defibrillation electrodes (102, 108). By doing so, it is possible to apply excitation stimulation to the heart from the periphery, and to effectively perform pacing.

Description

Technical Field

[0001] The present invention relates to an electrode-carrying cardiac net having electrodes which is mounted in a cardiac net of a heart as a treatment for a cardiac disease. Background Art

[0002] As a treatment for tachycardia, a pathologically accelerated heartbeat among heart diseases, an implantable defibrillator (ICD) is sometimes used. An implantable defibrillator is often used in a method in which electrodes are embedded in a predetermined position inside the heart through blood vessels, electrically connected to the implantable defibrillator body, and electricity is supplied from the implantable defibrillator body to the electrodes as needed to apply a defibrillation shock to the heart. As such, embedding electrodes inside the heart is highly invasive to the patient and imposes a greater burden on the patient, so a method of setting electrodes under the skin instead of inside the heart and a method of setting electrodes using a net mounted on the outside of the heart have also been proposed.

[0003] As a technique for disposing electrodes on the outside of the heart using a mesh or the like, for example, the following conventional techniques can be cited.

[0004] US Patent Publication No. US2002 / 10103511 discloses a technique in which a lead wire is braided into a mesh called an outer sheath for covering the heart and installed, and the wire is used as an electrode for receiving electrical pulses from an implantable defibrillator.

[0005] US Patent No. 6,076,013 discloses a technique in which electrodes are arranged on a mesh portion of a cardiac network and used for sensing the working state of the heart and pacing the ventricles.

[0006] Japanese Patent Laid-Open Publication No. 2009-536560 discloses a technique of disposing a flat-plate electrode on a cardiac sheath covering the heart and a technique of using a metal strand constituting the sheath by partially removing the covering thereof as an electrode.

[0007] Japanese Patent Laid-Open Publication No. 2016-537178 discloses a technique of providing electrodes on a mesh portion of a net attached to the heart.

[0008] Japanese Patent Laid-Open Publication No. 2011-56182 discloses a technique in which electrodes for defibrillation and electrodes for pacing are separately provided on a flat pad-shaped electrode assembly.

[0009] In addition, among heart diseases, there is also heart failure in which the function of the heart is reduced due to a hypertrophic phenomenon called cardiac remodeling. For such heart failure, it is known that covering the heart with an elastic heart mesh is effective in order to suppress cardiac remodeling. Summary of the invention

[0010] Problem that the invention aims to solve

[0011] As described above, electrodes are used for various purposes such as defibrillation to remove ventricular fibrillation generated in the heart, ventricular pacing to suppress ventricular tachycardia, and detection, i.e., sensing, of the working conditions of the heart. However, in biventricular pacing performed to suppress ventricular tachycardia, it can be said that there are still about 30% of cases where sufficient effects are not obtained. In these cases, it is also expected that the effects can be obtained if the electrodes are set in a more appropriate manner. Such problems are common in implantable defibrillators or implantable defibrillators with ventricular resynchronization therapy functions.

[0012] An object of the present invention is to solve such a problem and to provide a technique for improving the pacing effect in a method of providing electrodes on the outside of the heart via a mesh.

[0013] Solutions for solving problems

[0014] The present invention can be configured as an electrode-carrying cardiac mesh, which is formed by joining a pacing electrode connected to a main device consisting of an implantable cardioverter defibrillator (ICD) or an implantable cardioverter defibrillator with a ventricular resynchronization therapy function (CRT / D) and a non-conductive portion, and is assembled in a manner covering the outside of the heart, wherein the non-conductive portion is a stretchable mesh obtained from non-conductive silk threads, and the pacing electrode is arranged on the lower side compared to 1 / 2 the height of the ventricle for pacing, and has a band-like shape that roughly horizontally covers more than half the circumference of the ventricle.

[0015] In the prior art, the electrodes for pacing are only point or flat electrodes in any of the methods of setting them inside the heart, setting them under the skin, and setting them outside the heart via a net or the like. In the past, it was believed that the reason why pacing could not achieve a sufficient effect was that such point or flat electrodes took time to reach the myocardium for the purpose of excitation stimulation or caused deviation. In contrast, according to the present invention, the pacing electrodes are arranged to cover more than half a circumference of the ventricle. Therefore, excitation stimulation can be applied synchronously from approximately the entire circumference of the ventricle, thereby improving the pacing effect. This is particularly useful in pacing at high heart rate.

[0016] Furthermore, in the present invention, the pacing electrode is disposed below the 1 / 2 height of the ventricle, and therefore is effective in contracting the ventricle so as to pump blood out of the heart.

[0017] Furthermore, the non-conductive part of the present invention is formed by a retractable net, so it also has the advantage of being able to stably configure the electrode in the heart as a whole. As the non-conductive thread, various fibers can be used if it is a living body compatible material. For example, it can be set to polyester, polytetrafluoroethylene, etc. The non-conductive thread can be a single fiber or a thread twisted together. In addition, although various weaving methods can be used, as an example, Indian weaving, mesh weaving, etc. can be applied. It can be constructed using other methods. Methods other than Indian weaving can also be used.

[0018] In the present invention, "half circumference or more of the ventricle" can be defined as a central angle of 180 degrees or more when connecting the center of gravity of a cross-sectional view of a ventricle cut substantially horizontally to both ends of the pacing electrode.

[0019] "Approximately horizontal" does not mean strictly horizontal, but does not matter even if it is tilted to some extent. When considering the movement of the ventricles that pump blood from the heart, it means the direction in which the pacing electrodes are arranged in a region of approximately synchronous contraction.

[0020] The pacing electrode is not only used for pacing, but also has a sensing function for detecting the working condition of the heart.

[0021] In the present invention, the pacing electrode can be in various forms such as a metal wire or a plate, but the pacing electrode can also be a stretchable net made of conductive wires.

[0022] According to the above method, due to the elasticity of the mesh, it is possible to stably arrange the pacing electrode along the heart. As for the mesh, as with the non-conductive part, it can be formed by various weaving methods such as Indian weaving and mesh weaving. As the conductive thread, various materials can be applied, but for example, tungsten, stainless steel, platinum, platinum-iridium alloy, nickel-titanium alloys such as nitinol, carbon nanotubes (CNT: Carbon Nano Tube), resin materials filled with conductive fillers, etc. can be used. Regarding the material used, it can be selected by considering conductivity, compatibility with living bodies, ease of forming the mesh, i.e. weaving properties and strength, cost, etc. The conductive thread can be a single fiber or a twisted wire.

[0023] It is known that the heart net is useful as a treatment for heart failure in which the function of the heart is reduced due to a hypertrophic phenomenon called cardiac remodeling. As a heart net for such a purpose, a heart net that applies a moderate sense of pressure to the heart is preferred. The sense of pressure can be obtained by a pre-simulation to obtain a suitable value range. By making the electrode-carrying heart net of the present invention also have elasticity that can apply the sense of pressure obtained in this way, it is also possible to form a heart net that also has a compression function to suppress cardiac remodeling.

[0024] However, due to the following reasons, the electrode-carrying heart net of the present invention may be configured to not necessarily have a compression function for cardiac remodeling. Not all patients who use implantable defibrillators or implantable defibrillators with ventricular resynchronization therapy function are accompanied by cardiac remodeling and thus do not necessarily need a compression function. In addition, for patients who need a compression function, a method of further assembling a heart net with a compression function on top of the electrode-carrying heart net of the present invention is also considered. When considering this, by configuring the electrode-carrying heart net of the present invention to have a structure that does not necessarily have a compression function, the electrode-carrying heart net of the present invention does not need to change the weaving method depending on whether the compression function is needed or not, and can be applied to both patients. In addition, there is an advantage that the difficulty of weaving a heart net that applies a desired sense of compression using two materials, non-conductive silk thread and conductive silk thread, can be avoided.

[0025] In the present invention, the pacing electrode may be configured to cover the entire circumference of the ventricle.

[0026] By doing so, excitation stimulation can be applied from all around the ventricle, which can further enhance the pacing effect.

[0027] In the present invention, as the pacing electrode, a first pacing electrode and a second pacing electrode connected in parallel to the main device may be arranged one above the other.

[0028] The above method is a method with two pacing electrodes. When the main device composed of an implantable defibrillator or an implantable defibrillator with ventricular resynchronization therapy function is used for unipolar electrodes, the first pacing electrode and the second pacing electrode are respectively formed into one strip electrode. When the main device is used for bipolar electrodes, the first pacing electrode and the second pacing electrode are respectively formed of two strip electrodes constituting a positive electrode and a negative electrode.

[0029] When two pacing electrodes are arranged up and down like this, it becomes possible to further improve the pacing effect by utilizing various utilization methods shown below. As a first utilization method, it is possible to apply an excitation stimulus synchronized with the contraction movement of the heart to deliver blood by flowing an electric current with a time difference from the electrode on the lower side and the electrode on the upper side of the heart. In addition, as a second utilization method, it is possible to synchronize the refractory period of the myocardium relatively widely between the two electrodes by flowing an electric current simultaneously in the first electrode and the second electrode, so that it can function as a blocking line for blocking the abnormal transmission of excitation signals such as the spiral entry that causes ventricular fibrillation. Utilizing these effects, the above-mentioned method becomes possible to further improve the pacing effect. In particular, it is highly useful as pacing for tachycardia.

[0030] The above-mentioned aspects are not intended to limit the present invention to the invention including two pacing electrodes, and the invention may include only one pacing electrode or may include three or more pacing electrodes.

[0031] In the present invention, the pacing electrode may be configured to cover the center of the spiral entry that induces ventricular fibrillation.

[0032] In normal cases, the signal conveying excitement in the heart is transmitted from the atrium to the ventricle in a one-way manner, but in abnormal cases, a loop in which the signal circulates in the ventricle is sometimes formed, which is called a spiral entry. Moreover, it is known that this spiral entry is one of the causes of ventricular tachycardia. Based on this reason, it is expected that the ventricular tachycardia can be effectively suppressed by covering the center of the spiral entry with a pacing electrode.

[0033] The position of the spiral entry can be determined for each patient by using a pre-simulation, test, etc. In addition, the position of the spiral entry is not strictly determined as one position, but there are many cases where it converges to a certain range even if it changes. In addition, the pacing electrode is not completely ineffective when it is slightly deviated from the center of the spiral entry. Therefore, if the pacing electrode is configured in a manner covering the center of the spiral entry determined by simulation, etc., it is expected that the effect of suppressing ventricular tachycardia can be fully achieved even if the position where the spiral entry occurs changes slightly.

[0034] In the present invention, a defibrillation electrode may be further provided which is constituted by a stretchable net made of conductive threads and is connected to the main device and used for defibrillation of the heart.

[0035] According to the above method, the electrodes for defibrillation can be arranged in a wide range outside the heart, so compared with the method of embedding electrodes inside the heart, defibrillation can be effectively performed with low power. In addition, the defibrillation electrodes are also composed of a mesh of conductive threads, so they have the advantage of being able to be arranged relatively stably along the heart at an appropriate position of the heart.

[0036] In addition, the above-mentioned method has the following advantages. Generally, the electric power used for defibrillation of the heart is larger than the electric power used for ventricular pacing. Therefore, it has the following advantages: by separating the defibrillation electrode for defibrillation that handles relatively large electric power from the pacing electrode for ventricular pacing that handles relatively small electric power and current, it is easy to form electrodes suitable for each purpose.

[0037] Furthermore, in order to perform defibrillation, it is important to accurately detect whether ventricular fibrillation has occurred. However, in the above-mentioned method, if the pacing electrode is also used for the sensing function, there is also the following advantage: even if no dedicated sensing electrode is provided, detection can be performed with high accuracy.

[0038] In the case of a method in which a pacing electrode and a defibrillation electrode are provided, the defibrillation electrodes are arranged above and below the heart, and the pacing electrode may be arranged between the defibrillation electrodes arranged above and below.

[0039] When confirming the defibrillation effect in various configurations of the electrodes around the heart, up and down, left and right, and front and back of the heart, it was found that the effect can be achieved with the minimum power in the configuration of up and down. Therefore, according to this result, it is preferred to configure the defibrillation electrodes up and down. In addition, if the pacing electrode is arranged between the defibrillation electrodes, the degree of freedom of the arrangement is improved, so it can be arranged at a position suitable for ventricular pacing.

[0040] The defibrillation electrode can be arranged to cover more than half of the heart in a substantially horizontal manner similarly to the pacing electrode. In addition, the electrode can be formed into a pad shape.

[0041] In the case of providing a pacing electrode and a defibrillation electrode, the area of ​​the defibrillation electrode may be set larger than the area of ​​the pacing electrode.

[0042] The electric power used for defibrillation is usually greater than the electric power used for ventricular pacing. Therefore, by setting the areas of the defibrillation electrode and the pacing electrode as described above, it is possible to process the respective electric powers without waste.

[0043] The sizes of both can be set arbitrarily based on power and the like.

[0044] In the various aspects described above, the non-conductive portion may be formed of an absorbent thread.

[0045] By doing so, the risk of the non-conductive portion causing infection or the like in the body can be reduced.

[0046] In the case where the electrode-carrying heart net of the present invention is a structure that does not apply a sense of pressure to the heart for suppressing heart remodeling, the non-conductive part only plays the role of holding the electrode. Therefore, after being mounted on the heart, depending on the shape of the electrode, there may be a situation where it is not necessary to hold it by the non-conductive part. The above method is particularly useful in the case where the non-conductive part does not have the function of applying a sense of pressure to the heart.

[0047] In addition, when the non-conductive part is composed of absorbent threads, it is necessary to keep the electrode in a proper position even after the non-conductive part is absorbed. From such a viewpoint, it is preferred that the electrode is set in a shape surrounding the heart. In this way, the electrode can be kept in a proper position on the heart by its elastic force.

[0048] The present invention further comprises a connector having a socket for inserting a standardized lead wire for connecting to the main device, and the lead wires from the electrodes of the electrode-carrying cardiac network can be connected to the socket.

[0049] By doing so, it is possible to connect the electrode-carrying heart net and the main device relatively easily, and it is also possible to suppress accidental disconnection. Generally, various standardized leads are already present between the main device consisting of an implantable defibrillator or an implantable defibrillator with a ventricular resynchronization therapy function and the electrodes of the heart. Therefore, it is preferable to connect the electrode-carrying heart net and the main device using these leads in terms of convenience and reliability.

[0050] In this case, various methods are considered for connecting the standardized lead wire to the electrode-carrying heart net. For example, a method is considered in which the lead wires are connected to the electrodes of the electrode-carrying heart net after the plug at the front end of the lead wire is removed to expose the lead wires in the lead wire. However, in such a method, when a disconnection occurs in the connection portion with any electrode, the entire implantable defibrillator including the electrode-carrying heart net and the main device must be replaced. In addition, there is a risk that the reliability of the lead wire is reduced at the time when the lead wire at the front end of the standardized lead wire is exposed.

[0051] In contrast, in the above-mentioned method, by using a connector, it is possible to connect the electrode heart net and the main device using a standardized lead wire as is. Furthermore, after the electrode heart net and the main device are individually assembled or arranged in the body, the two can be connected by a lead wire, so the workability during assembly can be improved. In addition, as long as the two can be configured in a manner that the relative position of the connector relative to the electrode heart net is stable, it is possible to suppress the external force from acting on the wire connected to the electrode of the electrode heart net, so that the disconnection in this part can be suppressed. Furthermore, it also has the following advantages: even if a failure of the main device occurs, the electrode heart net is kept assembled as it is and only the main body can be replaced.

[0052] The lead wires to the electrodes can be connected in various ways. For example, a part of the conductive wire constituting the electrode can be directly extended to the outside and used as the lead wire.

[0053] Furthermore, the conductive wire may be woven into a mesh constituting each electrode.

[0054] By doing so, the lead wire can be connected with a relatively simple structure. In addition, there is an advantage that the manufacturing can be simplified compared with extending a part of the conductive wire constituting the electrode.

[0055] The conductive wire can be woven in various ways, but as an example, the conductive wire may be woven so as to form a loop in a mesh constituting each electrode.

[0056] By doing so, the conductive wire itself can be given elasticity, so that disconnection can be further suppressed. In addition, the contact area between the conductive wire and the electrode can be increased, and conductivity can be ensured.

[0057] The lead wire can be installed in various ways, for example, multiple lead wires can be installed for each electrode. By doing so, even when a part of the lead wire is disconnected, it is not necessary to exchange the electrode heart net but to utilize other lead wires to be connected to the main device.

[0058] The present invention does not necessarily need to include all of the various features described above, and some of them may be omitted or combined as appropriate.

[0059] Furthermore, the present invention can be configured in various forms other than the form of the electrode-carrying cardiac mesh.

[0060] For example, the present invention may be configured as an implantable defibrillator device, which uses a wire to connect any of the above-mentioned electrode-carrying cardiac networks to a main device consisting of an implantable defibrillator or an implantable defibrillator with a ventricular resynchronization therapy function.

[0061] In addition, it can also be set as a design method of a heart network with electrodes, which is a design method of a heart network with electrodes using a computer, and includes the following steps executed by the computer: a step of determining the position of the patient's spiral entry through simulation; and a step of determining the configuration of the electrodes in a manner covering the determined center. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is an explanatory diagram showing the overall structure of an implantable defibrillator.

[0063] Figure 2 It is a line graph showing the success rate of defibrillation corresponding to the arrangement of defibrillation electrodes.

[0064] Figure 3 : is an explanatory diagram showing a configuration example of electrodes.

[0065] Figure 4 1 is a flow chart showing the manufacturing process of the electrode-carrying cardiac mesh. DETAILED DESCRIPTION

[0066] Figure 1 1 is an explanatory diagram showing the overall structure of an implantable defibrillator. The implantable defibrillator in the embodiment is configured such that an implantable defibrillator body 200 and an electrode-carrying cardiac network 100 are connected by a lead wire 130 .

[0067] The implantable defibrillator body 200 can utilize various existing devices, and may be any of an implantable defibrillator (ICD: Implanted Cardioverter Defibrillator) or an implantable defibrillator with ventricular resynchronization therapy function (CRT / D: Cardiac Resynchronization Therapy Defibrillator). In this embodiment, a defibrillator having the functions of detecting, i.e. sensing, cardiac operation, and ventricular pacing and defibrillation is utilized. Either a unipolar or bipolar device may be used.

[0068] Lead wires 130 are standardized for connection with implantable defibrillator body 200. Examples of the standard include DF1, DF4, and IF1.

[0069] The electrode-carrying heart net 100 is a net installed in a manner of covering the heart from the lower side. The electrode-carrying heart net 100 is formed by connecting non-conductive parts 101, 103, 105, 107, defibrillation electrodes 102, 108 and pacing electrodes 104, 106. The non-conductive parts 101, 103, 105, 107 are elastic nets formed by weaving non-conductive threads using methods such as Indian weaving. As the non-conductive threads, polyester, polytetrafluoroethylene, etc. can be used. As the non-conductive threads, absorbent threads can also be used.

[0070] In this embodiment, the pacing electrodes 104 and 106 are also used to sense the working state of the heart.

[0071] The defibrillation electrodes 102, 108 and the pacing electrodes 104, 106 are respectively elastic nets formed by weaving conductive threads by methods such as Indian weaving. As the conductive threads, various materials can be applied, and for example, tungsten, stainless steel, platinum, platinum-iridium alloy, nickel-titanium alloys such as nitinol, carbon nanotubes (CNT: Carbon Nano Tube), resin materials filled with conductive fillers, etc. can be used. The thickness of the thin wire can be determined arbitrarily, but for example, it can be set to about 20 to 30 microns.

[0072] In the present embodiment, different materials are used in the defibrillation electrodes 102, 108 and the pacing electrodes 104, 106. Fibers composed of CNT monomers are used in the pacing electrodes 104, 106. On the other hand, platinum thin wires are used in the defibrillation electrodes. Generally, a large current flows in a relatively short period of time in defibrillation, while pacing is used in the form of a continuous flow of a small current. Therefore, the impedance of the defibrillation electrode is set to about 0.5 to 2 ohms, while the impedance of the pacing electrode is set to about 150 ohms. By doing so, the current flowing in the pacing electrode can be suppressed, making the battery durable. In addition, by using different materials in the defibrillation electrode and the pacing electrode, it is possible to form electrodes corresponding to the different power consumption in each.

[0073] The connection of the non-conductive parts 101, 103, 105, 107, the defibrillation electrodes 102, 108 and the pacing electrodes 104, 106 can be realized by switching between non-conductive threads and conductive threads according to the parts when weaving the cardiac mesh 100 with electrodes from the lower end, i.e., the defibrillation electrode 108, or from the upper end, i.e., the non-conductive part 101. In addition, the parts can be connected to each other after being individually woven.

[0074] The defibrillation electrodes 102 and 108 are electrodes for defibrillation. The pacing electrodes 104 and 106 are electrodes for sensing the operation of the heart and ventricular pacing. In the present embodiment, the defibrillation electrodes 102 and 108 are respectively formed to cover the periphery of the heart approximately horizontally and are arranged vertically. The pacing electrodes 104 and 106 are also formed in a belt shape so as to cover the periphery of the heart approximately horizontally and are arranged between the defibrillation electrodes 102 and 108.

[0075] In this embodiment, the width of the defibrillation electrodes 102 and 108 is wider than that of the pacing electrodes 104 and 106, and as a result, the area of ​​the electrodes 102 and 108 is larger than that of the pacing electrodes 104 and 106. Generally, the power used for cardiac defibrillation is larger than the power used for ventricular pacing. The defibrillation electrodes 102 and 108 are electrodes for cardiac defibrillation, and the pacing electrodes 104 and 106 are electrodes for cardiac defibrillation. Therefore, by setting the area corresponding to the power supplied to both, the power corresponding to the respective functions can be effectively used.

[0076] Figure 1 The shapes and configurations shown are merely examples. The shapes, areas, and locations of the defibrillation electrodes 102, 108 and the pacing electrodes 104, 106 may be arbitrarily determined in consideration of their respective functions. For example, the defibrillation electrodes do not necessarily need to be arranged in a manner surrounding the heart, and may also be pad-shaped electrodes.

[0077] The defibrillation electrodes 102, 108 and the pacing electrodes 104, 106 are connected to the connector 120 via the wires 110, 111, 112, 113. The wires 111 to 113 are installed in a manner of being woven into the respective electrodes. In the figure, an enlarged view of the connection area A of the defibrillation electrode 108 and the wire 113 is shown at the lower right. As shown in the figure, a wire thread 108h is woven into the defibrillation electrode 108. The example in the figure is a crocheted braid.

[0078] The conductor 113 is installed by being woven into the eye of the braided needle. In the example in the figure, the conductor 113 is woven while forming a loop suitable for a knot. By doing so, the conductor 113 can also be expanded and contracted in coordination with the expansion and contraction of the electrode-carrying cardiac network 100, and breakage can be suppressed. In addition, the contact area between the conductor 113 and the electrode can be increased, and conductivity can be ensured. In addition, various weaving methods such as a method of weaving in a straight line and a method of weaving in a zigzag shape can be applied to the conductor 113. In addition, when using a twisted wire as the conductor 113, it can be made so that each single wire constituting the twisted wire is woven in after the front end is spread out. The conductors 110 to 112 are also woven into their respective electrodes in the same manner.

[0079] A socket 121 adapted to fit a plug provided at the front end of the lead wire 130 is mounted on the connector 120. The lead wires 110 to 113 are electrically connected to the socket 121 in such a manner as to realize the functions of defibrillation, sensing, and ventricular pacing. In this way, the electrode-carrying cardiac network 100 and the implantable defibrillator body 200 can be electrically connected by the lead wire 130.

[0080] When the implantable defibrillator is installed in the body, after the implantable defibrillator body 200 and the electrode-carrying cardiac network 100 are assembled, the lead wire 130 is connected to the connector 120. By using the connector 120 in this way, the workability of installing the implantable defibrillator can be improved. In addition, by using the connector 120, it is possible to suppress the external force from acting on the wires 110 to 113, and it is possible to suppress the wires 110 to 113 from falling off.

[0081] Figure 2 : is a line graph showing the success rate of defibrillation corresponding to the configuration of defibrillation electrodes. Defibrillation electrodes are electrodes used for defibrillation. Figure 1 Various configurations are possible other than the positions shown. Therefore, the electrodes were configured at various positions and their effects on defibrillation were confirmed. Figure 2 The upper side of schematically shows the configuration of electrodes corresponding to each case. Respectively, Figure 2 Line graph L1 shows the results of the case where the electrodes are arranged up and down, line graph L2 shows the results of the case where the electrodes are arranged in a manner opposite to each other on the left and right sides of the heart, line graph L3 shows the results of the case where the electrodes are arranged in a manner opposite to each other on the front and back sides of the heart, and line graph L4 shows the results of the case where the electrodes are arranged in a manner that includes the entire heart. As shown in the figure, it is understood that for the same defibrillation energy, in the case where the electrodes are arranged up and down (line graph L1), the success rate of defibrillation is higher than in any other case. That is, it is considered preferable to arrange the electrodes up and down for defibrillation. Based on such results, Figure 1 The defibrillation electrodes 102 and 108 in the present embodiment shown are arranged above and below the heart. However, such experimental results do not negate arrangements other than above and below with respect to the arrangement of defibrillation electrodes.

[0082] Next, we will explain in detail Figure 1 The electrode configuration is shown in .

[0083] Figure 3: is an explanatory diagram showing an example of electrode configuration. In this example, the shape, area and configuration of the pacing electrode 106 are set to cover the center of the spiral entry formed in the ventricle. The curve S in the figure represents the spiral entry, and the point C represents its center. The spiral entry means that the exciting signal that should be transmitted from the atrium to the ventricle in a one-way manner forms a circling loop as shown in the figure due to some abnormality. It can be said that the spiral entry causes ventricular tachycardia. Therefore, in the manner shown in the figure, the pacing electrode 106 is configured in a manner covering the center of the spiral entry, that is, point C. By doing so, electrical stimulation can be directly applied to the spiral entry that causes ventricular tachycardia, which can improve the effect of suppressing ventricular tachycardia.

[0084] The position where the spiral entry occurs can be determined by simulation, testing, etc. However, the position of the spiral entry is not limited to a strictly fixed position, and errors may occur in its determination. Therefore, it is preferable to consider the error and variation of point C and determine the shape and area of ​​the pacing electrode 106 in a manner that can cover them.

[0085] In this embodiment, the pacing electrode 106 is a band-shaped electrode that covers the periphery of the ventricle approximately horizontally, and is arranged on the lower side compared to half (H / 2) of the height H of the ventricle. By doing so, it is possible to effectively apply excitation stimulation in a manner consistent with the heart activity of pumping blood. In the case of the implantable defibrillator body 200 of the unipolar type, the pacing electrode 106 is a single band, and in the case of the bipolar type, the pacing electrode 106 can be arranged in a manner of two bands, a positive band and a negative band, arranged vertically.

[0086] Furthermore, in the present embodiment, the pacing electrode 104 is provided on the upper side of the pacing electrode 106. The pacing electrode 104 is also a band-shaped electrode that covers the periphery of the ventricle substantially horizontally, similarly to the pacing electrode 106. Furthermore, when the implantable defibrillator body 200 is a unipolar type, the pacing electrode 104 is a single band, and when it is a bipolar type, the pacing electrode 104 can be provided in a manner in which two bands, a positive band and a negative band, are arranged vertically.

[0087] The position of the pacing electrode 104 can be arbitrarily set. The pacing electrode 104 does not necessarily need to be located below half the height of the ventricle (H / 2).

[0088] The width of the pacing electrodes 104 and 106 in the height direction can be set arbitrarily, but is preferably less than about 10 cm, more preferably less than 5 cm, and further preferably about 2 cm. In the present embodiment, it is set to about 2 cm. It is preferred that the pacing electrodes 104 and 106 be set to achieve an impedance of about 150 ohms so that power consumption can be suppressed.

[0089] By configuring the pacing electrodes 104 and 106 up and down, various utilization methods are possible. As a first utilization method, by flowing current from the electrode on the lower side of the heart and the electrode on the upper side with a time difference, it is possible to apply an excitation stimulus synchronized with the contraction movement of the heart to pump blood. In addition, as a second utilization method, by flowing current simultaneously in the first electrode and the second electrode, it is possible to synchronize the refractory period of the myocardium between the two electrodes to a relatively wide extent, so that it can act as a blocking line for blocking the abnormal transmission of excitation signals such as the spiral entry that causes ventricular fibrillation. Utilizing these effects, the above-mentioned method can further improve the pacing effect. In particular, it is highly useful as pacing for tachycardia.

[0090] However, it is also possible to adopt a method in which only the pacing electrode 106 is provided or a method in which three or more pacing electrodes are provided.

[0091] The horizontal cross section of the heart is shown at the lower side of the figure. The right ventricle RV, the left ventricle LV and the wall of the heart around them are schematically shown. As shown in the figure, the pacing electrode 106 is configured to cover the entire circumference of the heart. When current flows in the pacing electrode 106, excitation stimulation is synchronously applied to the heart from the surroundings as shown by the arrows in the figure. Therefore, the heart can be effectively contracted to deliver blood. In addition, by covering the two ventricles, the activities of the two ventricles can be synchronized.

[0092] However, the pacing electrode 106 does not necessarily need to cover the entire circumference. The pacing electrode 106A in the figure can be provided instead of the pacing electrode 106. The pacing electrode 106A covers the left ventricle LV side, but does not cover the right ventricle RV side. The center angle ANG connecting the two ends of the pacing electrode 106A to the center of gravity CG of the heart in the cross-sectional view is greater than 180 degrees. It is considered that if more than half of the circumference of the ventricle is covered in this way, the effect obtained by applying excitation stimulation from the periphery of the heart can be obtained.

[0093] In the example shown in the figure, the pacing electrode 106A covers the left ventricle LV side, but it may be arranged to cover the right ventricle RV side, or may be arranged to cover a part of both ventricles. Various arrangements are possible.

[0094] Alternatively, one of the pacing electrodes 106, 104 may cover the entire circumference while the other may cover a portion of the circumference.

[0095] The pacing electrode can be set at any position by considering the configuration of the pacing electrode and the positional relationship with the defibrillation electrode. Figure 1 The surrounding shape and up and down configuration shown can also take other configurations.

[0096] However, when ventricular tachycardia is detected, the implantable defibrillator is usually used in the following order: first, the pacing electrode is energized to attempt ventricular pacing, and when ventricular fibrillation does not stop despite this, defibrillation is performed using the defibrillation electrode. In this sense, defibrillation can be said to be a last resort to stop the abnormality of the heart, and is more important than ventricular pacing. Therefore, it is considered preferable to prioritize the defibrillation electrode over the pacing electrode to determine the shape, area, and position of the two.

[0097] Figure 4 This is a flowchart showing the manufacturing process of the electrode-carrying heart net. This is a diagram showing the sequence of manufacturing the electrode-carrying heart net, and does not mean that all steps are automatically performed by a computer. Of course, as long as it is possible, the use of a computer is not denied. Therefore, the subject of implementing this manufacturing process includes both a computer and a designer (human). In the following description, both are explained with the implementer as the subject.

[0098] In this manufacturing process, first, the implementer uses simulation, testing, etc. to determine point C as the center position of spiral entry (step S10). Regarding the simulation, various known methods can be adopted. When manufacturing a heart mesh with electrodes dedicated to a specific patient, it is sufficient to perform the simulation using the data of the target patient. When manufacturing a universal heart mesh with electrodes applicable to multiple patients, it is sufficient to perform the simulation using the data of multiple patients. It is sufficient to determine the center position with a high probability of spiral entry statistically.

[0099] After the position of the spiral entry is determined, the implementer then sets the position and shape of the defibrillation electrodes, namely the defibrillation electrodes 102 and 108 (step S11). The conditions for setting are shown in the figure. As condition 1, the pacing electrodes 104 and 106 are arranged above and below. The position of the pacing electrodes is set by the next step, so it is sufficient to arrange them up and down while leaving space for pacing electrodes. However, it is preferable to determine the position and shape of the spiral entry in a manner that does not cover the center of the spiral entry.

[0100] As condition 2, a shape that surrounds the heart roughly horizontally. As exemplified for the defibrillation electrodes 102 and 108. By doing so, electric shock can be applied from the periphery of the heart, and defibrillation can be performed effectively. In addition, as long as the defibrillation electrodes are formed in a form surrounding the heart, it is also possible to suppress the deviation of the position due to the movement of the heart, etc. In the case of forming the non-conductive portion using absorbent threads, the form surrounding the heart is particularly useful in the sense of stabilizing the position of the electrode.

[0101] In addition, as condition 3, a width corresponding to the power for defibrillation is set. In the present embodiment, since very thin conductive threads are used to form the electrodes, if the width of the electrodes is narrowed, the resistance tends to increase. The power for defibrillation supplied when using the electrode heart network of the present embodiment is extremely small compared to the power used in the conventional implantable defibrillator of the type in which electrodes are embedded inside the heart. However, in defibrillation, a larger power is generally used compared to cardiac pacing. Therefore, when setting the shape and position of the defibrillation electrodes 102, 108, it is preferable to set their widths so that defibrillation can be performed sufficiently and efficiently according to the power supplied thereto.

[0102] It is not necessary to satisfy all of the conditions 1 to 3 for setting the defibrillation electrode. For example, a part or all of the conditions 1 to 3 may be set in a relaxed manner in consideration of the position (point C) where the spiral enters.

[0103] When the positions and shapes of the defibrillation electrodes 102 and 108 are set in this way, the operator then sets the positions and shapes of the pacing electrodes 104 and 106 (step S12). The conditions for setting are shown in the figure. Condition 1 is a condition that the center position (point C) of the spiral is covered. By doing so, cardiac pacing can be performed effectively. Condition 2 is a condition that the center angle (reference Figure 3 The ANG) is set to 180 degrees or more. By doing so, the effect of cardiac pacing can be further improved. It is not necessary to fully satisfy the conditions 1 and 2 for setting the pacing electrodes 104 and 106. For example, a part or all of the conditions 1 and 2 may be set in a relaxed manner in consideration of the position of the defibrillation electrode, etc. In addition, only the pacing electrode 106 may be set, or three or more may be set.

[0104] In this embodiment, the reason why the setting of the defibrillation electrodes 102 and 108 (step S11) is prioritized over the setting of the pacing electrodes 104 and 106 (step S12) is that the defibrillation electrodes 102 and 108 are considered to be more important as described above.

[0105] After the setting of the defibrillation electrodes and the pacing electrodes is completed in this way, the overall weaving is performed (step S13). If the shape and position of the defibrillation electrodes 102, 108 and the pacing electrodes 104, 106 are determined, the non-conductive parts 101, 103, 107 can be naturally shaped in a manner that connects them together. Regarding the overall weaving, either a) a method of appropriately switching the conductive thread and the non-conductive thread in the middle of weaving the electrode-carrying heart mesh to form the non-conductive part, the defibrillation electrode, and the pacing electrode; b) a method of connecting the non-conductive part, the defibrillation electrode, and the pacing electrode after individually weaving them can be adopted.

[0106] Finally, wires are inserted into each electrode (step S14). The wires are not shown in the figure. The front end of each wire can be connected to Figure 1 The connector 120 shown may also be connected directly to the lead 130 .

[0107] The electrode-carrying cardiac mesh can be manufactured through the above steps. Furthermore, if connected to the implantable defibrillator body 200 by the lead wire 130, the implantable defibrillator can be constructed as a whole.

[0108] According to the electrode-equipped cardiac network of the present embodiment and the implantable defibrillator using the same described above, the following various effects can be obtained.

[0109] First, in this embodiment, since the pacing electrode 106 is arranged to cover more than half of the circumference of the ventricle, Figure 3 As described in , pacing can be performed effectively.

[0110] In addition, in this embodiment, since each electrode and non-conductive part are formed by a stretchable net, the electrodes can be arranged along the heart, and the electrical contact with the heart is improved due to the stretchability. As a result, each function can be effectively exerted.

[0111] The present invention is not limited to the above-described embodiments, and various modifications can be made without changing the gist of the invention.

[0112] Industrial Applicability

[0113] The present invention can be used in an implantable defibrillator.

[0114] Explanation of symbols

[0115] 100, 100A Heart Net with Electrodes

[0116] 101, 103, 105, 107 Non-conductive parts

[0117] 102, 108 Defibrillation electrodes

[0118] 104, 106 Pacing Electrode

[0119] 108h Wire

[0120] 110~113 wire

[0121] 120 Connectors

[0122] 121 Socket

[0123] 130 Lead

[0124] 200 Implantable defibrillator body.

Claims

1. A cardiac network with electrodes, which is formed by joining a pacing electrode connected to a main device consisting of an implantable defibrillator or an implantable defibrillator with ventricular resynchronization therapy function and a non-conductive portion, and is assembled in a manner covering the outside of the heart, wherein: The non-conductive part is a retractable net made of non-conductive threads, The pacing electrode is disposed below half the height of the ventricle for pacing, and has a band-like shape that covers more than half the circumference of the ventricle in a substantially horizontal manner.

2. The electrode-carrying cardiac mesh according to claim 1, wherein: The pacing electrode is a stretchable mesh made of conductive wire.

3. The electrode-carrying cardiac mesh according to claim 1, wherein: The pacing electrodes cover the entire circumference of the ventricle.

4. The electrode-carrying cardiac mesh according to claim 1, wherein: As the pacing electrodes, a first pacing electrode and a second pacing electrode connected in parallel to the main device are arranged one above the other.

5. The electrode-carrying cardiac mesh according to claim 1, wherein: The pacing electrode is configured to cover the center of the spiral entry that induces ventricular fibrillation.

6. The electrode-carrying cardiac mesh according to claim 1, wherein: It further comprises a defibrillation electrode which is formed of a stretchable net made of conductive threads and is connected to the main device and is used for defibrillation of the heart.

7. The electrode-carrying cardiac mesh according to claim 6, wherein: The defibrillation electrodes are arranged above and below the heart. The pacing electrode is arranged between the defibrillation electrodes arranged one above the other.

8. The electrode-carrying cardiac mesh according to claim 6, wherein: The area of ​​the defibrillation electrode is larger than the area of ​​the pacing electrode.

9. The cardiac mesh with electrodes according to any one of claims 1 to 8, wherein: The non-conductive portion is formed of absorbent threads.

10. The cardiac mesh with electrodes according to any one of claims 1 to 8, wherein: further having a connector, The connector is provided with a socket for inserting a standardized lead wire for connecting to the main device. Lead wires from each electrode of the electrode-bearing cardiac mesh are connected to the sockets.

11. The electrode-carrying cardiac mesh according to claim 10, wherein: The conductive wires are woven into the mesh forming each electrode so as to form a loop.

12. An implantable defibrillator device, which uses a wire to connect the electrode-carrying cardiac network according to any one of claims 1 to 11 to a main device consisting of an implantable defibrillator or an implantable defibrillator with ventricular resynchronization therapy function.

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