JP2020065843A - In vivo potential measuring instrument, in vivo potential measuring method, and in vivo potential measuring system - Google Patents

Abstract

To provide an in vivo potential measuring instrument capable of accurately measuring a potential of a cautery site when the periphery of an inner wall surface of an organ is cauterized in an ablation treatment, etc.SOLUTION: An in vivo potential measuring instrument which is inserted into an organ of a living body for measuring a potential of a predetermined site on an inner wall surface of the organ includes: a hollow bag-like insulating member; and a hollow tubular member connected to a first electrode disposed in the hollow part of the insulating member and the insulating member. A conductive fluid is injected into the hollow part of the insulating member through the hollow tubular member, and in the state that the outer peripheral surface of the insulating member is brought into contact with the inner wall surface of the organ, a potential of the site in contact is measured by the first electrode. A second electrode electrically connected to the fluid that exists inside the hollow tubular member is disposed in the hollow tubular member, and the second electrode adjusts a potential of the fluid.SELECTED DRAWING: Figure 5

Description

  The present invention is provided with an in-vivo potential measuring instrument that is inserted into an organ of a living body and measures the potential of a predetermined site on the inner wall surface of the organ, an in-vivo potential measuring method, and an in-vivo potential measuring instrument. The present invention relates to an in-vivo potential measuring system.

  BACKGROUND ART A catheter is inserted into an organ such as a blood vessel to inspect or treat a lesion.

  One of the treatments using a catheter is catheter ablation treatment with a balloon. This treatment involves attaching a balloon to the tip of a catheter, inflating the balloon by injecting a liquid into the balloon, and then warming the liquid in the balloon with a high-frequency current to cauterize the organ in contact with the surface of the balloon. For example, it is applied to the treatment of atrial fibrillation.

  According to this treatment, since the balloon has a flexible spherical shape, the outer peripheral surface of the inflated balloon is formed into a ring shape on the inner wall surface in the vicinity of the junction between the left atrium and the pulmonary vein, which is the treatment site for atrial fibrillation. Because they can be contacted, they can cauterize around the pulmonary veins at once.

  On the other hand, after cauterizing an organ by ablation treatment, the potential of the organ in the vicinity of cautery is measured in order to confirm the cauterizing effect. For example, in Patent Document 1, a catheter having a plurality of electrodes for measuring potential at the tip is inserted into an organ, each electrode is brought into contact with an organ in the vicinity of cauterization, and the potential of a portion where each electrode is in contact is determined. The method of measurement is described.

Japanese Patent No. 5870694

  11 (a) to 11 (c) show a method of measuring the potential of an organ in the vicinity of cauterization by using a conventional electrode for potential measurement after cauterizing the organ in contact with the balloon using a catheter with a balloon. It is the figure which showed. In addition, here, the vicinity of the junction between the left atrium and the pulmonary vein, which is a treatment site for atrial fibrillation, will be described as an example of the ablation site.

  As shown in FIG. 11A, the catheter 10 having the balloon 30 attached to the tip thereof is inserted near the junction between the left atrium 50 and the pulmonary vein 51. Then, by injecting the liquid 21 into the balloon 30, the balloon 30 is inflated and the outer peripheral surface of the balloon 30 is brought into contact with the inner peripheral surface of the organ 52 in a ring shape. Reference numeral 60 indicates an abnormal electrical signal source that is the origin of atrial fibrillation.

  Next, as shown in FIG. 11B, a high-frequency current is passed through the first electrode 20 to warm the liquid 21 in the balloon 30, thereby cauterizing the organ 52 in contact with the surface of the balloon 30. . As a result, a cauterized site (cauterization site) 61 is formed at the site of the organ with which the balloon 30 is in contact.

  Next, as shown in FIG. 11C, the catheter 10 with a balloon is pulled out, and the catheter 100 having a plurality of electrodes (Lasso electrodes) 110 for measuring potential at the tip is inserted up to the vicinity of the ablation site 61. Then, the plurality of electrodes 110 are brought into contact with the organ 52, and the potential of the contacted portion is measured.

  However, when the ring-shaped electrode 110 as shown in FIG. 11C is used, the potential of the site where the plurality of electrodes 110 contact is measured intermittently, so the potential of the site between the electrodes is not measured. .

  On the other hand, the conduction path of the abnormal electric signal in atrial fibrillation extends around the pulmonary vein 51. Therefore, in order to cut off the conduction path of the abnormal electric signal, all the sites where the surface of the balloon 30 contacts in a ring shape. Needs to be cauterized. Therefore, even if there is a site that cannot be cauterized (uncauterized site), if the plurality of electrodes 110 are not in contact with the uncauterized site, the potential of the site that is not in contact is not measured. As a result, there is a risk of overlooking the presence of an uncauterized region, and thus the cauterizing effect cannot be accurately confirmed.

  Further, the ring-shaped electrodes 110 are not sufficiently flexible, or are too flexible and excessively deformed, so that it is difficult to bring all the electrodes 110 into contact with the organ 52. If some of the electrodes 110 are not in contact with the organ 52, the potential of the part that is not in contact is not measured, and there is a risk of missing the existence of an uncauterized part.

  Further, as shown in FIG. 11C, the position where the ring-shaped electrode 110 is in contact may be displaced from the ablation site 61. In this case, since the ring-shaped electrode 110 measures the potential of the portion deviated from the cauterization portion 61, the cauterization effect cannot be accurately confirmed.

  In addition, after cauterizing with the balloon 30, it is necessary to temporarily remove the catheter 10 with the balloon 30 and insert a new catheter 100 equipped with the ring-shaped electrode 110, so it takes a long time to confirm the cauterizing effect. I need it. In addition, the risk of air mixing in the organ increases due to the insertion and removal of the catheters 10 and 110.

  The present invention has been made in view of the above problems, and its main purpose is, for example, in ablation treatment, the potential of the cauterization site when cauterizing the periphery of the inner wall surface of the organ, and in vivo that can be accurately measured. To provide an electric potential measuring device.

  The in-vivo potential measuring device according to the present invention is an in-vivo potential measuring device which is inserted into an organ of a living body to measure the potential of a predetermined portion on the inner wall surface of the organ, and which has a hollow bag-shaped insulating member. A hollow portion of the insulating member, the first electrode being arranged in the hollow portion of the insulating member, and a hollow tubular member coupled to the insulating member. In the state where the conductive fluid is injected into the inner surface of the insulative member and the inner wall surface of the organ is contacted, the potential of the contacted portion is measured by the first electrode, and the hollow tubular member is Is arranged with a second electrode electrically connected to the fluid existing inside the hollow tubular member, and the second electrode adjusts the potential of the fluid. .

  According to the present invention, it is possible to provide an in-vivo potential measuring device capable of accurately measuring the potential of the ablation site when the periphery of the inner wall surface of the organ is ablated by ablation treatment or the like.

It is the figure which showed typically the structure of the in-vivo electric potential measuring device in a reference form. It is the figure which showed typically the state where the outer peripheral surface of the insulating member contacted the inner wall surface of the organ. FIG. 6 is an equivalent circuit diagram showing a method of measuring the potential of a portion where the outer peripheral surface of the insulating member contacts the inner wall surface of the organ in the reference mode, using an electrode arranged in the insulating member. In a reference form, it is a graph which showed the waveform of the voltage measured with the amplifier after cauterization. It is the figure which showed typically the structure of the in-vivo electric potential measuring device which concerns on embodiment. FIG. 6 is an equivalent circuit diagram showing a method of measuring the potential of a portion where the outer peripheral surface of the insulating member contacts the inner wall surface of the organ in the embodiment, with an electrode arranged in the insulating member. 6 is a graph showing a waveform of a voltage measured by an amplifier after cauterization in the embodiment. (A) ~ (c), after cauterizing the inner wall surface of the organ using the insulating member, the outer peripheral surface of the insulating member is in contact with the inner wall surface of the organ, the potential of the contacted portion FIG. 5 is a diagram illustrating a method of measuring with electrodes arranged in an insulating member. It is the figure which showed typically the structure of the in-vivo electric potential measuring device which concerns on another embodiment. FIG. 8 is an equivalent circuit diagram showing a method of measuring the potential of a portion where the outer peripheral surface of the insulating member is in contact with the inner wall surface of the organ in another embodiment, with an electrode arranged in the insulating member. (A)-(c) shows the method of measuring the electric potential of the organ in the vicinity of cauterization using the electrode for conventional electric potential measurement after cauterizing the organ which contacted the balloon using the catheter with a balloon. It is a figure. It is the figure which showed typically the structure of the in-vivo electric potential measuring device which concerns on other embodiment. It is the figure which showed typically the structure of the in-vivo electric potential measuring device which concerns on another embodiment.

  Before explaining the present invention, a background of how the inventors arrived at the present invention will be described. As one means for solving the above-mentioned problem, instead of the conventional electrode for measuring potential as shown in FIG. 11 (c), an electrode is arranged inside the balloon so that the balloon comes into contact with an organ of a living body. The inventor has found out that the electric potential of the contacting portion is measured by the electrode inside the balloon in the state of being operated. Therefore, it is considered possible to accurately measure the potential of the ablation site when the periphery of the inner wall surface of the organ is ablated by ablation treatment or the like.

(Reference form)
FIG. 1 is a diagram schematically showing the configuration of the above-mentioned in-vivo potential measuring device devised by the inventor. Hereinafter, the in-vivo potential measuring device of the reference embodiment is referred to. In the following drawings, including the embodiments, components having substantially the same functions are denoted by the same reference numerals for simplification of description. Incidentally, this in-vivo potential measuring device is to be inserted into an organ of a living body to measure the potential of a predetermined site on the inner wall surface of the organ. Here, in the catheter ablation treatment of atrial fibrillation, it is cauterized. The case of measuring the electric potential at the subsequent cauterization site will be described as an example.

  As shown in FIG. 1, the in-vivo potential measuring device according to the reference embodiment includes an insulating member 30 whose outer peripheral surface is deformable or expandable, and a first electrode 20 arranged in the insulating member 30. I have it. As the insulating member 30, for example, a hollow bag-shaped balloon can be used. Further, in the reference embodiment, a balloon-attached catheter in which the flexible hollow catheter 10 is coupled to the insulating member 30 is used.

  FIG. 1 shows that by injecting a conductive fluid 21 into the insulating member 30, the outer peripheral surface of the insulating member 30 is divided into the left atrium 50 and the pulmonary vein 51, which are treatment sites for atrial fibrillation. It shows a state in which the inner wall surface of the organ 52 near the junction is contacted in a ring shape. Here, the conductive fluid 21 can be injected from the outside via the catheter 10 using the pump 120. The pump 120 and the catheter 10 are connected by a liquid passage tube 130. A portion indicated by reference numeral 11 is a part of the catheter 10 and is a liquid passage tube connecting portion 11. Further, as the conductive fluid 21, for example, physiological saline or the like can be used.

  The in-vivo potential measuring device according to the reference mode, as shown in FIG. 1, in a state where the outer peripheral surface of the insulating member 30 is in contact with the inner wall surface of the organ 52 in a ring shape, the potential of the contacted portion is The measurement is performed by the first electrode 20 arranged in the insulating member 30.

  As for the potential of the portion where the insulating member 30 contacts, as shown in FIG. 1, the ground electrode 71 serving as a reference is attached to the surface 72 of the living body, and the first electrode is placed inside the insulating member 30. The voltage between the electrode 20 and the ground electrode 71 can be measured by amplifying the voltage with the amplifier 70 arranged outside the living body. The ground electrode 71 is connected to the amplifier 70 by the third energization line 156.

  In addition, the insulating member 30 has a first energization line 152 connected to the first electrode 20 arranged in the insulating member 30 in a state where the outer peripheral surface of the insulating member 30 is in contact with the inner wall surface of the organ. A high-frequency current 200 may be applied to the first electrode 20 to heat the fluid 21 to thereby cauterize the portion in contact with the insulating member (ablation function). The generator 140 generates a high frequency current. The high-frequency current 200 flows from the generator 140 to the first energization line 152 through the second energization line 154. When the fluid 21 is heated, the fluid 21 is caused to flow inside the insulating member 30 by using the pump 120 so that a temperature difference is not generated inside the insulating member 30 (convection inside is indicated by an arrow 210. Shown). As a result, the fluid 21 is agitated inside the insulating member 30, and the temperature inside the insulating member 30 becomes uniform.

  Next, the principle of measuring the potential inside the living body by the measuring instrument according to the reference embodiment shown in FIG. 1 will be described with reference to FIGS. 2 and 3.

  FIG. 2 is a diagram schematically showing a state where the outer peripheral surface of the insulating member 30 is in contact with the inner wall surface of the organ 52. Here, since the fluid 21 injected into the insulating member 30 has conductivity, the potential of the inner peripheral surface of the insulating member 30 in contact with the fluid 21 is equal to that of the insulating member 30. It is considered to be substantially the same as the potential of the first electrode 20 disposed within 30. Therefore, as shown in FIG. 2, the first electrode 20 and the inner wall surface of the organ 52 constitute the capacitive coupling type electrode 80 with the insulating member 30 sandwiched therebetween.

  FIG. 3 is an equivalent circuit showing a method of measuring the potential of a portion where the outer peripheral surface of the insulating member 30 contacts the inner wall surface of the organ 52, with the first electrode 20 arranged in the insulating member 30. It is a figure. Here, Vb is a potential measured at the site where the insulating member 30 contacts the inner wall surface of the organ 52, and Ce represents the capacitance between the first electrode 20 and the organ 52. It should be noted that Vb is measured at the contact site by transmitting the barycentric potentials of a plurality of potentials around the organ 52. Further, a ground electrode 71 serving as a reference is attached to the surface 72 of the living body, and the voltage between the first electrode 20 and the ground electrode 71 is amplified by the amplifier 70 and measured as the output voltage Vout. To be done. Cin is the input capacitance of the amplifier 70, and Rin is the input resistance of the amplifier 70.

In the equivalent circuit shown in FIG. 3, the following equation (1) is established from Kirchhoff's second law.

  Here, Zce is the impedance of the electrostatic capacitance between the electrode and the organ, and Zcin is the impedance of the input capacitance of the amplifier.

Further, in the closed loop circuit of the amplifier 70, the following equation (2) is established according to Kirchhoff's first law.

By solving for i ₂ using the equations (1) and (2), the following equation (3) is obtained.

Further, the following equation (4) is established from Ohm's law.

By substituting the equation (3) into the equation (4), the following equation (5) is obtained.

The first and second terms of the denominator of equation (5) are expressed as equations (6) and (7), respectively.

  By substituting the equations (6) and (7) into the equation (5), the following equation (8) is obtained.

Here, when the input capacitance Cin of the amplifier 70 is sufficiently small and the input resistance Rin is sufficiently large, that is, when the following equations (9) and (10) are satisfied, the equation (8) becomes the following equation. It is expressed as (11).

  That is, the voltage Vout measured by the amplifier 70 matches the potential Vb of the site where the insulating member 30 contacts the inner wall surface of the organ 52. As a result, the potential Vb at the site where the insulating member 30 contacts the inner wall surface of the organ 52 can be easily measured by the amplifier 70.

By the way, the capacitance Ce between the electrode and the organ shown in FIG. 2 is represented by the following formula (12), where S is the contact area between the insulating member 30 and the organ and d is the thickness of the insulating member 30. Represented by.

Here, ε ₀ is the dielectric constant of vacuum (8.855 × 10 ⁻¹² [F / m]), and ε _r is the relative dielectric constant of the insulating member 30.

  Therefore, when the potential Vb of the site where the insulating member 30 contacts the inner wall surface of the organ 52 is obtained using the formula (11), the thickness d of the insulating member 30 is set so that the formula (9) is satisfied. It is preferable.

For example, assuming that the input capacitance Cin of the amplifier 70 is 10 pF, the contact area S between the insulating member 30 and the organ is 1000 mm ² , and the relative dielectric constant ε _r of the insulating member 30 is 5 (for example, in the case of polyurethane), the expression ( From 9), d <45 μm. Therefore, the thickness d of the insulating member 30 is typically 40 μm or less, and more preferably 10 μm or less.

  Further, in order to obtain the potential Vb of the site where the insulating member 30 contacts the inner wall surface of the organ 52 using the equation (11), the input resistance Rin of the amplifier 70 is set so that the equation (10) is satisfied. Preferably.

  For example, the input capacitance Cin of the amplifier 70 is 10 pF, the electrostatic capacitance Ce between the electrode and the organ is 1000 pF (Cin / Ce = 0.01), and the potential band f at the site where the insulating member 30 contacts the inner wall surface of the organ 52. When (jw = 2πf) is 100 Hz, Rin> 0.2 GΩ is obtained from the equation (10). Therefore, the input resistance Rin of the amplifier 70 is typically preferably 1 GΩ or more.

  Next, with reference to FIGS. 8A to 8C, after cauterizing the inner wall surface of the organ using the insulating member 30 according to the present embodiment, the outer peripheral surface of the insulating member 30 is placed inside the organ. A method of measuring the potential of the contacted portion with the first electrode 20 arranged in the insulating member 30 in the state of being in contact with the wall surface will be described. In addition, here, the vicinity of the junction between the left atrium and the pulmonary vein, which is a treatment site for atrial fibrillation, will be described as an example of the ablation site.

  First, as shown in FIG. 8A, a flexible member (catheter) 10 having an insulating member (balloon) 30 attached to its tip is inserted near the junction between the left atrium 50 and the pulmonary vein 51. Then, by injecting the conductive fluid 21 into the insulating member 30 using the pump 120, the insulating member 30 is inflated so that the outer peripheral surface of the insulating member 30 is the inner peripheral surface of the organ 52. Make a ring-shaped contact. Reference numeral 60 indicates an abnormal electrical signal source that is the origin of atrial fibrillation.

  In FIGS. 8B and 8C, a high-frequency current is passed through the first electrode 20 to heat the fluid 21 in the insulating member 30 to contact the surface of the insulating member 30. The state after cauterizing the organ 52 is shown. Here, FIG. 8B shows a state in which sufficient cauterization has not been performed over the periphery of the organ 52, and a part that has not been cauterized (an uncauterized part) remains. On the other hand, FIG. 8C shows a state in which sufficient cauterization is performed around the periphery of the organ 52, and a cauterized part (cauterizing part) 61 is formed.

  In the state shown in FIG. 8B, when the potential of the portion where the outer peripheral surface of the insulating member 30 contacts is measured by the first electrode 20 arranged in the insulating member 30, it contacts in a ring shape. Since the electric potentials of all parts are superposed, the electric potentials of the uncauterized parts are measured. Therefore, in this case, it can be confirmed that the ablation by the ablation treatment was insufficient.

  On the other hand, in the state shown in FIG. 8C, when the potential of the portion where the outer peripheral surface of the insulating member 30 contacts is measured by the first electrode 20 arranged in the insulating member 30, the unburned portion The electric potential at is not measured by being superimposed. Therefore, in this case, it can be confirmed that the ablation by the ablation treatment was sufficient.

  When the measurement was performed using the measuring instrument shown in FIG. 1 based on the above principle, a potential as shown in FIG. 4 was measured. However, upon detailed examination, it was found that noise was superimposed on the portion N in FIG. 4, and an accurate potential could not be measured. The present inventors have come to the present invention as a result of various investigations in order to measure an accurate potential.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments below. Further, appropriate changes can be made without departing from the scope of the effect of the present invention.

(Embodiment 1)
The configuration of the in-vivo potential measuring device according to the first embodiment is schematically shown in FIG. In the in-vivo potential measuring device according to the present embodiment, the second electrode 73 is arranged in the liquid-passing tube 130 that is a hollow tube. The second electrode 73 is electrically connected to the conductive fluid 21 existing inside the liquid passage tube 130, and the second electrode 73 adjusts the potential of the fluid 21. This is different from the in-vivo potential measuring device according to the reference embodiment shown in FIG. In other respects, this embodiment has almost the same configuration as the reference embodiment. The liquid passing tube 130 and the catheter 10 are collectively referred to as a hollow tubular member.

  As shown in FIG. 5, the in-vivo potential measuring device according to the present embodiment is arranged in a hollow bag-shaped insulating member 30 whose outer peripheral surface is deformable or expandable, and a hollow portion of the insulating member 30. And the first electrode 20 is formed. In addition, in the present embodiment, a catheter with a balloon in which the flexible and hollow tubular catheter 10 is coupled to the insulating member 30 is used.

  In FIG. 5, by injecting the conductive fluid 21 into the insulating member 30, the outer peripheral surface of the insulating member 30 is joined to the left atrium 50 and the pulmonary vein 51, which are the treatment sites for atrial fibrillation. It shows a state in which the inner wall surface of the organ 52 in the vicinity is contacted in a ring shape. Here, the conductive fluid 21 can be injected from the outside via the catheter 10 using the pump 120. The pump 120 and the catheter 10 are connected by a liquid passage tube 130. Further, as the conductive fluid 21, for example, physiological saline or the like can be used.

  The liquid passage tube 130 is provided with an electrode connection member 132, and by inserting the second electrode 73 therein, the second electrode comes into contact with the fluid 21. The electrode connecting member 132 is in a hermetically sealed state even when the second electrode 73 is inserted or when the second electrode 73 is pulled out, and leaks the fluid 21 to the outside. Without a role as a part of the liquid passage tube 130.

  In the present embodiment as well, as in the measuring instrument according to the reference embodiment, the potential of the contacted portion is measured in the insulating member 30 while the outer peripheral surface of the edging member 30 is in contact with the inner wall surface of the organ 52 in a ring shape. The measurement is performed by the first electrode 20 arranged at.

  The potential of the portion where the insulating member 30 comes into contact is between the first electrode 20 disposed inside the insulating member 30 and the ground electrode 71 by attaching the reference ground electrode 71 to the surface 72 of the living body. The voltage is measured by amplifying the voltage of (1) with an amplifier 70 arranged outside the living body. At this time, the ground electrode 71 is connected to the amplifier 70 by the third energization line 156, and the second electrode 73 is also connected to the ground electrode 71 and the amplifier 70 by the fourth energization line 158. As described above, the second electrode 73 is connected to the ground electrode 71 and the amplifier 70, so that the potential inside the fluid 21 is adjusted.

  The insulating member 30 also has a function of cauterizing a portion where the insulating member contacts (ablation function). The contact portion is cauterized by heating the fluid 21 by applying a high-frequency current 200 to the first electrode 20 while the outer peripheral surface of the insulating member 30 is in contact with the inner wall surface of the organ. The high frequency current 200 is generated by the generator 140 and supplied via the first energization line 152. The first energization line 152 is connected to the first electrode 20, and the high-frequency current 200 flows through the second energization line 154 to the first energization line 152, and then is supplied to the first electrode 20.

  Here, when the high-frequency current 200 is supplied to the first electrode 20 and the fluid 21 is heated by the heat generation of the first electrode 20, the heated fluid 21 moves upward, so that inside the insulating member 30. In, the temperature of the upper side becomes high and the temperature of the lower side becomes low. When a temperature difference occurs inside the insulating member 30 as described above, even if the insulating member 30 is in contact with the entire inner wall surface periphery of the organ 52 in the same manner, cauterization is performed in the high temperature portion but cauterization is performed in the low temperature portion. If not, or even if it is cauterized over the entire circumference, the degree of cauterization in the high temperature portion will be too great and cauterization will occur more than necessary. Therefore, the fluid 21 is made to flow inside the insulating member 30 using the pump 120 so that such a temperature difference (temperature distribution) does not occur inside the insulating member 30 (convection inside is shown by an arrow 210). ). As a result, the fluid 21 is stirred inside the insulating member 30, and the temperature inside the insulating member 30 becomes uniform.

FIG. 6 shows a method of measuring the potential of a portion where the outer peripheral surface of the insulating member 30 of the present embodiment is in contact with the inner wall surface of the organ 52, with the first electrode 20 arranged in the insulating member 30. The equivalent circuit diagram is shown below. By connecting the second electrode 73 to the ground electrode 71, the currents i _1A and i _2A and the output voltage VoutA differ from the equivalent circuit diagram of the reference embodiment shown in FIG.

  Next, FIG. 7 shows the in-vivo potential measured by the first electrode 20 in the present embodiment. It can be seen from the comparison with FIG. 4 that the noise is removed from the portion S. As a result of examining the cause of this noise, the inventor of the present application has found that the noise is a change in electric potential caused by friction between the fluid 21 and the inner wall of the hollow tubular member when the fluid 21 moves inside the hollow tubular member. I found him. That is, in order to prevent a temperature difference (temperature distribution) inside the insulating member 30, the pump 120 is used to repeat the inflow and outflow of the fluid 21 into the insulating member 30. The fluid 21 is being agitated at, and the change in the potential of the fluid 21 due to the inflow and outflow causes noise.

  In the present embodiment, the second electrode 73 is electrically connected to the fluid 21 in the electrode connecting member 132 of the liquid passage tube 130 which is a part of the hollow tubular member. Since the second electrode 73 is also connected to the ground electrode 71, it is possible to eliminate the fluctuation of the potential generated in the fluid 21. The second electrode 73 thus adjusts the electric potential of the fluid 21.

  According to the present embodiment, after the organ 52 is cauterized by ablation treatment, when measuring the potential of the organ in the vicinity of the cautery, the outer peripheral surface of the insulating member 30 is brought into contact with the inner wall surface of the organ 52 in a ring shape. Then, since the potential of the contacted portion is measured by the first electrode 20 arranged in the insulating member 30, the potential of the organ 52 near the cautery can be reliably measured over the surroundings. As a result, when there is an unburned portion, it can be measured as a potential on which the potential of the unburned portion is superimposed. As a result, the presence of an uncauterized part is not overlooked, so that the cauterizing effect can be surely confirmed.

  In addition, since the outer peripheral surface of the insulating member 30 is made of a material that is deformable or expandable, the outer peripheral surface of the insulating member 30 can be easily formed on the inner wall surface of the organ 52 according to the shape of the organ 52. Can be contacted in a ring shape. As a result, the potential of the organ 52 near the cautery can be reliably measured over the circumference. As a result, when there is an uncauterized portion, the cauterizing effect can be surely confirmed without overlooking its existence.

  In addition, the insulating member 30 has a function of cauterizing a portion where the insulating member 30 contacts by applying a high-frequency current to the first electrode 20, so that an organ in the vicinity of the cauterization at the same position as the cauterized portion. Since the potential of 52 can be measured, the cauterizing effect can be confirmed accurately.

  In addition, the potential of the organ 52 near the cautery is measured by a capacitance coupling type electrode formed by sandwiching the insulating member 30 between the first electrode 20 and the organ 52, and thus the potential across the circumference at once. Can be measured.

  Moreover, since the insulating member 30 is formed of a hollow bag-shaped balloon, the film thickness of the insulating member 30 becomes constant, so that the potential around the organ 52 can be measured without variation.

  Further, when measuring the potential of the organ 52 in the vicinity of cauterization, it is not necessary to insert and remove the insulating member 30, so that the cauterizing effect can be confirmed in a short time. Further, it is possible to reduce the risk of air being mixed into the organ 52 due to the insertion / removal of the insulating member 30.

  Since the second electrode 73 is electrically connected to the fluid 21, the potential change (noise) generated in the fluid 21 can be removed, and the potential in the living body can be measured more accurately. You can In addition, noise that is superimposed on the potential inside the living body can be removed with a simple configuration in which the second electrode 73 is electrically connected to the fluid 21.

  When the second electrode 73 is extracted from the electrode connecting member 132, the amplifier 70 can measure noise.

  In addition, in the present embodiment, the in-vivo potential measuring device that measures the potential at a predetermined site on the inner wall surface of the organ has a simple structure in which the electrodes are arranged in the insulating member, thereby improving biocompatibility and safety. It is possible to realize an excellent in-vivo potential measuring device.

  The in-vivo potential measuring method in the present embodiment is a in-vivo potential measuring method for measuring the potential of a predetermined site on the inner wall surface of an organ of a living body, and includes the following steps (A) to (C), and measures the potential. Is performed by measuring the voltage between the first electrode and a ground electrode serving as a reference, and the second electrode electrically connected to the fluid inside the hollow tubular member is the ground electrode. Connected with.

(A) A step of inserting a hollow bag-shaped insulating member into an organ of a living body by using a hollow tubular member bonded to the insulating member. (B) Inside the insulating member, through the hollow tubular member, Step of injecting a conductive fluid to bring the outer peripheral surface of the insulating member into contact with the inner wall surface of the organ (C) Step of measuring the potential of the contacted portion with the first electrode In vivo in the present embodiment The potential measuring system includes the in-vivo potential measuring device shown in FIG. 5 and an amplifier 70 that amplifies the potential detected by the first electrode 20.

(Embodiment 2)
The configuration of the in-vivo potential measuring device according to the second embodiment is schematically shown in FIG. The second embodiment is different from the first embodiment in that a coil 90, which is a noise removing circuit, is connected to the second electrode 73, and other points are the same as those in the first embodiment. Differences from the above will be described below.

  In the present embodiment, the coil 90 is provided on the fourth energization line 158 connected to the second electrode 73. By this coil 90, noise generated for some reason inside the balloon catheter or in the measurement circuit, or noise caused by the outside can be removed.

FIG. 10 shows a method of measuring the potential of a portion where the outer peripheral surface of the insulating member 30 of the present embodiment is in contact with the inner wall surface of the organ 52 with the first electrode 20 arranged in the insulating member 30. It is the equivalent circuit diagram shown. By connecting the second electrode 73 to the ground electrode 71, the currents i _1B and i _2B and the output voltage VoutB differ from the equivalent circuit diagram of the reference embodiment shown in FIG.

  In the present embodiment, in addition to the effects of the first embodiment, since the coil 90 is arranged, the in-vivo electric potential can be measured more accurately.

(Embodiment 3)
The configuration of the in-vivo potential measuring device according to the third embodiment is schematically shown in FIG. In the third embodiment, in the electrode connection member 132 of the liquid passage tube 130 which is a part of the hollow tubular member, the second A electrode 74 and the second B electrode 75 are used as the second electrodes electrically connected to the fluid 21. It is equipped with two. Further, a noise canceling circuit 77 to which the second A electrode 74 and the second B electrode 75 are connected is provided. These points are different from the first embodiment, and the other points are the same as the first embodiment. Therefore, the points different from the first embodiment will be described below.

  In the present embodiment, the potential of the fluid 21 is captured by the second B electrode 75, the fluctuation of the potential is measured by the noise canceling circuit 77, and a signal in which the phase of the fluctuation is inverted is generated and sent to the second A electrode 74. The potential fluctuation of the fluid 21 is canceled. The second B electrode 75 that captures the potential of the fluid 21 is located closer to the pump 120 that causes the potential fluctuation than the second A electrode 74. With this configuration, the potential fluctuation caused by the flow of the fluid 21 can be canceled by the noise canceling circuit 77, and the potential of the living organ can be measured more accurately than in the first embodiment.

(Embodiment 4)
The configuration of the in-vivo potential measuring device according to the fourth embodiment is schematically shown in FIG. The fourth embodiment is different from the third embodiment in that the coils 90 and 91 which are the noise removing circuits are connected to the second A electrode 74 and the second B electrode 75, respectively, and the other points are the same as the third embodiment. Since they are the same, the points different from the third embodiment will be described below.

  In the present embodiment, coils 90 and 91 are provided between the second A electrode 74 and the second B electrode 75 and the noise canceling circuit 79, respectively. With the coils 90 and 91, noise generated for some reason inside the balloon catheter or in the measurement circuit, or noise caused by the outside can be removed. Therefore, the electric potential of the living organ can be measured more accurately than in the third embodiment.

(Other embodiments)
Although the present invention has been described above with reference to the preferred embodiment, such description is not a limitation and, of course, various modifications can be made. For example, although the hollow bag-shaped balloon is described as an example of the insulating member 30 in the above-described embodiment, the insulating member 30 is not limited to this, and the first electrode 20 for potential measurement is covered with the insulating member 30. May be Alternatively, the first electrode 20 for measuring the potential may be covered with the insulating member 30 via the conductive fluid 21.

  The second electrode 73 is arranged near the outlet of the pump 120, but it may be arranged anywhere on any part of the hollow tubular member. The noise removal circuit 90 removes high-frequency noise generated in the ground electrode 72, the third energization line 156, and the fourth energization line 158 due to the operation of devices placed around the in-vivo potential measuring device according to the second embodiment. The structure is not particularly limited as long as it is a coil or a capacitor that can be formed.

  Further, in the above embodiment, the example of measuring the potential of the organ in the vicinity of the ablation after the ablation of the organ by the ablation treatment has been described, but before the ablation treatment, in order to diagnose the state of the lesion, the vicinity of the lesion It can also be applied when measuring the electric potential of the organ. In addition, the potential of the organ in the vicinity of the ablation may be measured in order to monitor the state of the ablation while the ablation treatment is being performed. In this case, the energization of the high-frequency current to the first electrode 20 and the measurement of the potential using the first electrode 20 may be alternately performed in a time division manner.

  In the above embodiment, the reference ground electrode 71 is arranged on the surface of the living body, but the ground electrode 71 may be arranged inside the living body. As a result, the potential of the organ can be measured in a state where noise is reduced due to the living body itself having a shielding effect. For example, the ground electrode 71 may be attached to the tip of the catheter. Further, a plurality of reference ground electrodes 71 may be arranged on the body surface or in the body, or a virtual ground electrode may be calculated from the plurality of ground electrodes.

  In addition, in the above-described embodiment, in a state where the outer peripheral surface of the insulating member 30 is in contact with the inner wall surface of the organ in a ring shape, the potential of the contacted portion is set to the first position in the insulating member 30. Although the example measured by the electrode 20 has been described, the present invention is not limited to this, and the first electrode 20 in which the insulating member 30 is pressed against a flat surface portion and the potential of the contacted portion is arranged in the insulating member 30. It may be measured by. For example, while the insulating member 30 is pressed against the planar inner wall surface of the organ and the insulating member 30 is deformed so as to follow the surface shape of the planar portion, the potential of the contacted portion is changed in the contact state. The measurement may be performed with the first electrode 20.

  Further, in the above embodiment, the in-vivo potential measuring device is described as an example in which it is applied to a scene of measuring the potential of an organ in the vicinity of ablation after ablation of the organ by ablation treatment, but the invention is not limited to this, and diagnosis and treatment are possible. Alternatively, in order to confirm the therapeutic effect, the insulating member 30 may be inserted into an organ of a living body and applied to any scene in which the potential of a predetermined portion on the inner wall surface of the organ is measured.

  Further, in the fourth embodiment, only one of the coils may be used.

10 catheter
20 First electrode
21 Conductive fluid
30 Insulating member (balloon)
52 organs
61 Cautery site
70 amplifier
71 Ground electrode
73 Second Electrode 74 Second A Electrode (Second Electrode)
75 Second B electrode (second electrode)
90 Noise removal circuit (coil)
91 Noise removal circuit (coil)
120 Stirring member (pump)

Claims (10)

An in-vivo potential measuring instrument which is inserted into an organ of a living body to measure an electric potential of a predetermined site on an inner wall surface of the organ,
A hollow bag-shaped insulating member,
A first electrode disposed in the hollow portion of the insulating member,
A hollow tubular member bonded to the insulating member,
Equipped with
Through the hollow tubular member, a conductive fluid is injected into the hollow portion of the insulating member,
In a state where the outer peripheral surface of the insulating member is in contact with the inner wall surface of the organ, the potential of the contacted portion is measured with the first electrode,
A second electrode electrically connected to the fluid existing inside the hollow tubular member is arranged in the hollow tubular member,
The second electrode is an in-vivo potential measuring device that adjusts the potential of the fluid.   The in-vivo potential measuring device according to claim 1, wherein the second electrode is connected to a reference ground electrode.   The in-vivo potential measuring device according to claim 1 or 2, further comprising a stirring member that stirs the fluid existing in the hollow portion of the insulating member via the hollow tubular member.   The in-vivo potential measuring device according to claim 1, wherein the insulating member and the hollow tubular member are balloon catheters.   5. The in-vivo potential according to claim 1, wherein the second electrode is connected to a circuit that inverts a phase of noise of potential of the fluid generated in the hollow tubular member. Measuring instrument.   The in-vivo potential measuring device according to claim 1, wherein the second electrode is further connected to a noise removing circuit that removes high frequency noise.   In the insulating member, the outer peripheral surface of the insulating member is in contact with the inner wall surface of the organ, a high-frequency current is passed through the electrode to heat the conductive fluid, thereby allowing the contact. The in-vivo potential measuring instrument according to any one of claims 1 to 6, which also has a function of cauterizing the formed portion. A method for measuring an electric potential in a living body, which measures an electric potential of a predetermined portion on an inner wall surface of an organ,
A step of inserting the hollow bag-shaped insulating member into the organ of the living body by using the hollow tubular member bonded to the insulating member;
In the insulating member, through the hollow tubular member, injecting a conductive fluid, the outer peripheral surface of the insulating member, to contact the inner wall surface of the organ,
A measuring step of measuring the potential of the contacted portion with a first electrode arranged in the insulating member,
The measurement of the potential of the contacted portion is performed by measuring the voltage between the first electrode and a reference ground electrode,
The in-vivo potential measuring method, wherein a second electrode electrically connected to the fluid existing inside the hollow tubular member is connected to the ground electrode.   The in-vivo potential measuring method according to claim 8, wherein, in the measuring step, the fluid in the insulating member is stirred by the stirring member via the hollow tubular member. An in-vivo potential measuring device according to any one of claims 1 to 7,
An in-vivo potential measuring system, comprising: an amplifier that amplifies a potential detected by the electrode.

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