JP2015020035A - Treatment method for treating foreign material in organism with treatment tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of quickly and highly accurately measuring the change in pressure generated due to contact between an electrode 41 and foreign material in an organism when treating the foreign material in the organism by inserting a treatment tool such as a catheter having the electrode 41 (detection/treatment means) 41 on the tip into the organism.SOLUTION: A pressure vibration body 1 including a piezoelectric vibrator 10 and a contact piece which has a swollen part 21 brought into contact with the piezoelectric vibrator 10 on one surface and a measurement object contact surface 22 on the surface opposite to the swollen part 21, the swollen part 21 being formed of an organic polymeric elastic material having a physical property indicating the change in a contact area between the swollen part and the piezoelectric vibrator when pressure is applied to the measurement object contact surface 22, is placed so that the measurement object contact surface 22 is brought into contact with an electrode (detection/treatment means) 41. The change in pressure generated due to contact between the electrode 41 and the foreign material is calculated from the change in impedance of the piezoelectric vibrator 10 of the pressure vibration body 1.

Description

  The present invention relates to a treatment method for treating a foreign substance in a living body with a treatment tool, and more particularly to a method for measuring a pressure generated by contact between a treatment means of a treatment tool and a foreign substance when the treatment method is performed. The present invention also relates to a pressure vibrator and a therapeutic device that can be advantageously used in the implementation of the method.

  As a method for treating tachyarrhythmia, there is known a method using a flexible tube and a catheter provided with an electrode (detection / treatment means) at the distal end of the flexible tube (ablation therapy). . Specifically, the ablation treatment is performed as follows. The catheter is passed through the patient's blood vessel and the tip electrode is inserted into the heart. Next, an electrode is brought into contact with the inner wall of the heart, and an electrocardiogram is measured to detect an abnormal site. Then, with the electrode in contact with the myocardium at the abnormal site, a high frequency (RF wave) current is generated from the electrode, and the high frequency current is irradiated to the abnormal site to cauterize the abnormal site. In this ablation treatment, it is necessary not to cauterize the normal part of the myocardium. Therefore, a pressure measuring means for measuring the pressure change caused by the contact between the electrode and the foreign substance in the flexible tube is attached to the catheter, and the electrode and the abnormal site are detected by the pressure measuring means. Measure the pressure generated by the contact of the electrode, irradiate the abnormal part with high frequency current while confirming the contact state between the electrode and the abnormal part, or calculate the ablation volume from the pressure, that is, the volume of the abnormal part. It has been studied to optimize the amount of high-frequency current applied to the site.

  Patent Document 1 discloses a flexible insertion tube for insertion into a living body, a distal tip (tip provided with an electrode), an elastic member that connects the distal tip to the flexible insertion tube, and a position. The use of a catheter with pressure measuring means with a sensor is described for measuring the pressure generated by the engagement of the distal tip with tissue. According to this document, in the catheter with pressure measuring means, the elastic member is deformed according to the pressure applied to the distal tip when the distal tip comes into contact with the tissue in the living body, and the position sensor is inserted flexibly. It is said that pressure can be measured by detecting the position of the distal tip relative to the distal end of the tube. In this document, as a method of detecting the position of the distal tip with respect to the distal end of the flexible insertion tube, a magnetic field generator is arranged at the distal tip, and at the distal end of the flexible insertion tube, A method of positioning a position sensor that generates a signal indicative of the position of the distal tip in response to a magnetic field is described.

  Patent Document 2 describes that a pressure generated by contact of a distal tip with a foreign object is measured, and an ablation volume is calculated based on the pressure. Note that, in the catheter with the pressure sensor described in this document, the position sensor detects the position of the distal tip with respect to the distal end of the flexible insertion tube in the same manner as the catheter with the measuring means described in Patent Document 1. Thus, the pressure is measured.

  On the other hand, Patent Literature 3 describes a gas pressure gauge that measures the pressure of a gas in a container from the impedance (AC resistance value) of a piezoelectric vibrator provided in the pressure container. According to this document, since the impedance of a piezoelectric vibrator that is placed in a pressure vessel and vibrates flexibly changes according to the pressure, a change in the pressure of the gas in the pressure vessel is detected by measuring the impedance of the piezoelectric vibrator. It is supposed to be possible. However, this document does not describe a method for measuring pressure generated by contact between a solid object and a piezoelectric vibrator.

JP 2009-90114 A JP 2011-134061 A JP-A-60-201225

  In the catheter with the pressure sensor described in Patent Documents 1 and 2, even when the distal tip is not in contact with the inside of the organ, or when the distal tip is bent along the curved blood vessel, the flexible insertion is possible. The position of the distal tip with respect to the distal end of the tube changes, and the amount of change in the position is detected as pressure. For this reason, when the distal tip is bent and contacts the inside of the organ, it is difficult to measure a change in pressure generated by contacting the distal tip and the inside of the organ.

  Accordingly, an object of the present invention is to develop a pressure measuring method that can detect a change in pressure with a fast response speed and can easily adjust the dynamic range of the measurable pressure according to the target object of the pressure. A method of measuring a pressure generated by contact between a treatment means such as an electrode and a foreign substance quickly and with high accuracy when a treatment tool such as a catheter is inserted into a living body to treat the foreign substance in an organ. An object of the present invention is to provide an apparatus that can be advantageously used for carrying out the method.

  The inventor has a piezoelectric vibrator comprising a plate-like piezoelectric body and electrodes provided on both sides of the piezoelectric body, and a bulging portion on one surface, the bulging portion being the piezoelectric vibration. Pressure vibrating body including a disk-shaped contact element arranged in contact with the surface of one electrode of the child, provided that the bulging part of the contact of the pressure vibrating body is provided with the bulging part of the contactor When the surface on the opposite side of the measured surface (hereinafter also referred to as the measurement object contact surface) is placed in contact with the surface of the object that causes a pressure change, the contact is made according to the change in the pressure of the object. It was made of an organic polymer elastic material having a physical property in which the contact area between the bulge portion of the child and the piezoelectric vibrator changes. Then, this pressure vibrator is placed on the surface of the human body with the contact surface of the object to be measured in contact with the contact of the pressure vibrator, so that the piezoelectric vibrator of the pressure vibrator has a resonance inherent to the piezoelectric vibrator. By applying an alternating voltage with a frequency corresponding to the frequency, the piezoelectric vibrator is brought into a vibration state, a current is taken out from the piezoelectric vibrator in the vibration state, and the change in the current value of the current and the alternating current applied to the piezoelectric vibrator The change in impedance of the piezoelectric vibrator was calculated from the voltage value of the voltage. As a result, it has been found that the pressure fluctuation due to human respiration applied to the measurement object contact surface of the pressure vibrator appears as the impedance fluctuation of the piezoelectric vibrator at a fast response speed. Further, the present inventor has found that the amount of fluctuation of the impedance of the piezoelectric vibrator with respect to the change of the pressure applied to the contact varies depending on the configuration of the material and shape of the contact of the pressure vibrator. Then, the present inventor arranges the contact of the above-described pressure vibration body so that the contact surface of the contact of the object to be measured contacts the surface of the detection / treatment means treatment, and the contact between the detection / treatment means and the foreign matter Is applied to the contact surface of the measurement object in contact with the contact detection / treatment means, and the bulging portion of the contact member of the pressure vibrating body is placed on the measurement object contact surface. By measuring the pressure vibration body of the treatment tool by forming it from an organic polymer elastic material with the physical property that the contact area between the bulge part of the contact and the piezoelectric vibrator changes according to the applied pressure change. The present invention has been reached because it can be used as a means.

Therefore, the present invention detects the physical or chemical foreign matter generated in the living body provided at the distal end of the flexible tube and the flexible tube, and detects the foreign matter in a state in contact with the foreign matter. A treatment instrument comprising: a pressure measuring means for measuring a pressure change caused by contact between the detection / treatment means and a foreign object in contact with the detection / treatment means in the flexible tube Prepare and insert the tip of the treatment device into the living body, detect foreign matter in the living body by the detection / treatment means, and then measure the pressure change caused by the contact between the detection / treatment means and the foreign matter by the pressure measurement means Then, a treatment method for treating the foreign substance by a treatment means,
The pressure measuring means includes a piezoelectric vibrator composed of a plate-like piezoelectric body and electrodes provided on both surfaces of the piezoelectric body, and a bulging portion on one surface, the bulging portion being the piezoelectric vibration. A disk-shaped contact element arranged in a state in which the surface opposite to the surface provided with the bulging portion is in contact with the surface of the detection / treatment means treatment while being in contact with the surface of one electrode of the child The bulging portion of the contact of the pressure vibrating body is generated by contact between the detection / treatment means and a foreign object, and is applied to the surface of the contact that contacts the detection / treatment means. Including a pressure vibrating body formed of an organic polymer elastic material having a physical property in which the contact area between the bulge portion of the contact and the piezoelectric vibrator changes in accordance with a change in pressure,
A method of measuring a pressure change generated by contact between a detection / treatment means and a foreign substance by an operation including the following steps.
Applying an alternating voltage having a frequency corresponding to the resonance frequency inherent to the piezoelectric vibrator to the piezoelectric vibrator of the pressure vibrator to bring the piezoelectric vibrator into a vibration state; a current from the piezoelectric vibrator in the vibration state From the change of the current value of the current generated according to the pressure change applied to the surface of the contactor in contact with the detection / treatment means and the voltage value of the AC voltage applied to the piezoelectric vibrator. Calculating a change in impedance of the vibrator; and converting the change in impedance into a change in pressure.

Preferred embodiments of the treatment method of the present invention are as follows.
(1) The measurement of the pressure change caused by the contact between the detection / treatment means and the foreign substance by the pressure measurement means is continued until the treatment of the foreign substance by the treatment means is completed.
(2) A step of calculating the volume of the foreign matter from the pressure change generated by the contact between the detection / treatment means and the foreign matter by the pressure measuring means.
(3) An abnormal site where a foreign object is formed in the myocardium.
(4) The detection means and the treatment means are composed of the same electrode.
(5) The piezoelectric body has a disk shape.
(6) The contact has a disk shape in which a bulge is formed on one surface.
(7) The contactor has a diameter to thickness ratio in the range of 1: 1 to 1: 1/5. However, the thickness of a contact means the thickness from the front-end | tip of a bulging part to the surface on the opposite side to the surface provided with the bulging part.
(8) The bulging part of the contactor is hemispherical. (9) The entire contactor is made of an organic polymer elastic material.

  The present invention also provides a flexible tube, a physical / chemical foreign matter generated in the living body provided at the tip of the flexible tube, and a detection / treatment for treating the foreign matter in contact with the foreign matter. Treatment means, a piezoelectric vibrator comprising a plate-like piezoelectric body and electrodes provided on both sides of the piezoelectric body, and a bulging portion on one surface, the bulging portion of the piezoelectric vibrator It includes a disk-like contactor disposed in contact with the surface of one of the electrodes and in a state where the surface opposite to the surface provided with the bulging portion is in contact with the surface of the detection / treatment means treatment The pressure vibrating body, but the bulging portion of the contact of the pressure vibrating body is generated by the contact between the detection / treatment means and a foreign object, and the pressure change applied to the surface of the contact that contacts the detection / treatment means Depending on the physical properties, the contact area between the bulge of the contact and the piezoelectric vibrator changes. By applying an alternating voltage having a frequency corresponding to the resonance frequency inherent to the piezoelectric vibrator to the piezoelectric vibrator of the pressure vibrator made of an organic polymer elastic material, the piezoelectric vibrator is brought into a vibration state. Means for extracting a current from a piezoelectric vibrator in a vibrating state; means for calculating a change in impedance of the piezoelectric vibrator from a change in current value of the current and a voltage value of an alternating voltage applied to the piezoelectric vibrator; and There is also a treatment device including means for converting the change in impedance into a change in pressure.

  By using the treatment method of the present invention, it is possible to quickly and accurately measure a pressure change generated by contact between a treatment / treatment means treatment of a treatment tool such as a catheter and a foreign body. By quickly and accurately measuring a pressure change caused by contact between the detection / treatment unit of the treatment tool and the foreign object, it is possible to quickly and accurately determine whether the detection / treatment unit and the foreign object are in contact with each other. Or the amount of high-frequency current applied to the foreign matter can be optimized with high accuracy. Moreover, the treatment method of the present invention can be advantageously carried out by utilizing the treatment tool of the present invention.

1 is a cross-sectional view of an example of a treatment tool according to the present invention. It is a partial exploded perspective view of the pressure measurement means with which the treatment tool of Drawing 1 was equipped. It is sectional drawing which shows the state which made the electrode with which the treatment tool of FIG. 1 was made to contact the surface of the biological heart. It is sectional drawing of another example of the pressure vibrating body which can be used for the treatment tool according to this invention. It is sectional drawing which shows the deformation | transformation state of a contact when a pressure is provided to the contact of the pressure vibrating body of FIG. 4, (a) is a state before giving a pressure to a contact, (b) is a contact. The state after applying pressure to is shown. It is a block diagram of the pressure measurement circuit which can be used advantageously for the measurement of the pressure change in the treatment method of this invention. It is a graph which shows the time-dependent change of the impedance of a piezoelectric vibrator measured by making the pressure vibration body of the structure which can be used for the treatment method of this invention contact the abdominal surface of a biological body. It is a graph which shows the relationship between the pressure provided to the contact of the pressure vibrating body of the structure which can be used for the treatment method of this invention, and the impedance of a piezoelectric vibrator.

  In the treatment method and treatment tool of the present invention, the physical or chemical foreign matter generated in the living body means an object that is physically or chemically different from normal tissues in the living body. An example of a foreign body is an abnormal site formed in the myocardium that causes tachyarrhythmia. The treatment method and treatment tool of the present invention will be described by taking an ablation treatment method using a catheter for treating an abnormal site formed in the myocardium as an example. FIG. 1 is a cross-sectional view of an example of a treatment tool according to the present invention, FIG. 2 is a partially exploded perspective view of pressure measuring means of the treatment tool of FIG. 1, and FIG. It is sectional drawing which shows a state when it is made to contact the inner surface of an organ.

  1 to 3, the treatment tool is provided in a state where it is in contact with the abnormal tube and the detection means provided at the distal end of the flexible tube 40 for detecting an abnormal region formed in the myocardium. An electrode 41 (detection / treatment means) that is a treatment means for treating an abnormal site, and a contact with the electrode 41 in the flexible tube 40 to measure a pressure change caused by the contact between the electrode 41 and a foreign object The pressure vibration body 1 which is a pressure measuring means is included. The electrode 41 is connected to a power cable 42 that passes through the center of the flexible tube 40. The outer diameter of the flexible tube 40 is generally in the range of 1.5 to 3.0 mm.

  The pressure vibrating body 1 includes a piezoelectric vibrator 10 and a contact 20. The piezoelectric vibrator 10 includes a plate-like piezoelectric body 11 and electrodes 12 and 13 provided on both side surfaces of the piezoelectric body 11. The piezoelectric vibrator 10 is preferably disk-shaped. The size of the piezoelectric vibrator is generally in the range of 0.1 to 0.5 mm in diameter. Examples of the material of the plate-like piezoelectric body 11 include ferroelectric ceramics such as lead zirconate titanate (PZT) and barium titanate. The electrodes 12 and 13 of the piezoelectric vibrator 10 are connected to lead wires 15a and 15b, respectively.

  The contact 20 is formed of a disk-like body having a bulging portion 21 on one surface. The contact 20 has a bulging portion 21 in contact with the surface of the electrode 12 on the distal end side of the piezoelectric vibrator 10 and a measurement object contact surface that is a surface opposite to the surface on which the bulging portion 21 is provided. 22 is arranged in contact with the surface of the electrode 41. A flange portion 23 is formed around the bulging portion 21 of the contact 20. The contact 20 is preferably disk-shaped. The diameter / thickness ratio of the contact 20 is preferably in the range of 1: 1 to 1: 1/5. The thickness of the contact 20 means the thickness from the tip of the bulging part 21 to the surface (measurement object contact surface 22) opposite to the surface provided with the bulging part. The bulging portion 21 of the contact is preferably hemispherical. The hemispherical shape means a shape obtained by cutting a sphere in a plane, but does not need to be a strict hemispherical shape. When the piezoelectric vibrator 10 has a disc shape, the contact 20 is preferably arranged so that the tip of the bulging portion 21 is in contact with the center of the piezoelectric vibrator 10.

  The bulging portion 21 of the contactor 20 bulges the contactor 20 in response to a pressure change generated by the contact between the electrode 41 and the abnormal part, which is applied to the measurement object contact surface 22 that contacts the electrode 41. The contact area between the portion 21 and the piezoelectric vibrator 10 is formed from an organic polymer elastic material having physical properties that change. The contact 20 may be formed of the same organic polymer elastic material as a whole. Further, the measurement object contact surface 22 may be formed of a hard organic polymer elastic material or metal that is harder than the material of the bulging portion 21. Examples of metals include aluminum, iron, and stainless steel. The organic polymer elastic material is preferably one of rubber, a thermoplastic resin and a thermoplastic elastomer, and particularly preferably rubber. Examples of rubber include natural rubber, silicone rubber, urethane rubber, polybutadiene rubber, isoprene rubber, styrene butadiene rubber, nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber, acrylic rubber, epichlorohydrin rubber, chloroprene rubber and acrylonitrile butadiene. Mention may be made of rubber. Examples of the thermoplastic resin include polyacetal resin, polyethylene resin, polyamide resin, and polyester resin.

  The contact 20 of the pressure vibrating body 1 is supported by the contact holding plate 43 in a state where the bulging portion 21 can be deformed by applying pressure to the measurement object contact surface 22. The contact holding plate 43 has one power cable hole 44 in the center, and around the power cable hole 44, four contact holes 45 are arranged at equal intervals. The contact 20 is inserted into each of the four contact holes 45 so that the contact 20 does not fall out of the contact hole 45 due to contact between the contact flange portion 23 and the contact holding plate 43. It is supported by. The piezoelectric vibrator 10 of the pressure vibrator 1 is fixed to the vibrator holding plate 46. The vibrator holding plate 46 has one power cable hole 47 in the center, and four vibrator holes 48 and lead wire holes 49 are arranged around the hole 47. The piezoelectric vibrators 10 are inserted into the four vibrator holes 48, respectively. The piezoelectric vibrator 10 is fixed to the vibrator hole 48 with an adhesive or the like. The lead wire 15a connected to the electrode 12 on the distal end side of the piezoelectric vibrator 10 is led out through the lead wire hole 49 to the rear side. By arranging four pressure vibrating bodies 1 around the power cable 42 passing through the center of the flexible tube 40 and measuring the change in pressure from the change in impedance of the piezoelectric vibrator 10 of each pressure vibrating body 1 The change in pressure and the inclination of the electrode 41 when the electrode 41 is brought into contact with the surface of the myocardium 2 can be detected. For example, as shown in FIG. 3, when the electrode 41 of the treatment instrument is tilted, the contact 20 a in the tilted direction of the electrode 41 is applied with a stronger pressure than the contact 20 b in the opposite direction. The contact area between the bulging part 21 of the contact 20a and the piezoelectric vibrator 10a is larger than the contact area between the bulging part 21 of the contact 10b and the piezoelectric vibrator 10b. For this reason, the change in the impedance of the piezoelectric vibrator 10a is larger than the change in the impedance of the piezoelectric vibrator 10b.

When performing the ablation treatment using the above-described treatment tool, an abnormal site is detected using the electrode 41 of the treatment tool. Then, the pressure generated by the contact between the electrode 41 and the abnormal part is converted into a change in pressure of a change in impedance of the piezoelectric vibrator 10 of the pressure vibrating body 1. Then, after confirming that the electrode 41 and the abnormal part are in contact with each other by the pressure change, a high-frequency current is generated from the electrode 41, and the abnormal part is irradiated with the high-frequency current to cauterize the abnormal part. The measurement of the pressure change caused by the contact between the electrode 41 and the abnormal part by the pressure vibrating body 1 may be continuously performed until the treatment of the abnormal part by the electrode 41 is completed. Further, the volume of the abnormal part may be calculated in advance from the pressure change measured by the pressure vibrating body 1, and the amount of the high-frequency current applied to the abnormal part may be adjusted according to the volume of the abnormal part.
In the treatment tool shown in FIGS. 1 to 3, the detection / treatment unit is provided on one electrode, but the detection unit and the treatment unit may be physically separated. When the detection means and the treatment means are separated, the pressure measurement means is preferably brought into contact with both the detection means and the treatment means or only the treatment means.

Next, another configuration of the pressure vibrator that can be used in the treatment device according to the present invention will be described.
FIG. 4 is a cross-sectional view of another example of a pressure vibrator that can be used in the treatment device according to the present invention. FIG. 5 is a cross-sectional view showing a deformed state of the contact when pressure is applied to the contact of the pressure vibrating body in FIG. 4, and (a) shows a state before pressure is applied to the contact (b) ) Shows a state after pressure is applied to the contact.

  In FIG. 4, the piezoelectric vibrator 10 has an upper surface electrode 12 attached to a vibrator case 14 via an adhesive (not shown). The electrode 12 on the upper surface of the piezoelectric vibrator 10 is extended to the lower surface of the piezoelectric body 11 by a folded electrode 12a. Lead wires 15a and 15b are connected to the folded electrode 12a and the lower electrode 13 respectively. The vibrator case 14 is preferably formed of a material that can vibrate together with the piezoelectric vibrator. Examples of the material of the vibrator case include a hard organic polymer elastic material that is harder than the metal and the material of the bulging portion 21 of the contactor 20. Examples of the metal material include aluminum and stainless steel. The contact 20 is preferably arranged so that the tip of the bulging portion 21 contacts the center of the vibrator case 14.

  As shown in FIG. 5, when pressure is applied to the measurement object contact surface 22, the pressure vibrating body 1 is crushed at the surface of the transducer case 14 by the tip of the bulging portion 21, and the bulging portion 21. And the contact area S between the vibrator case 14 and the vibrator case 14 are increased. In a state where the piezoelectric vibrator 10 is vibrated by applying a resonance frequency voltage to the piezoelectric vibrator 10 of the pressure vibrating body 1, the contact area between the bulging portion 21 and the piezoelectric vibrator 10 (the bulge of the contact 20). When the portion 21 and the electrode 12 of the piezoelectric vibrator 10 are in contact with each other via the vibrator case 14, when the contact area between the bulging portion 21 of the contact 20 and the vibrator case 14 changes, the piezoelectric vibration The impedance of the child 10 changes. The reason why the impedance of the piezoelectric vibrator 10 changes is that vibration energy of the piezoelectric vibrator 10 (vibration energy of the vibrator case 14 when the piezoelectric vibrator 10 is housed in the vibrator case 14) This is considered to be because the vibration energy of the piezoelectric vibrator 10 is reduced by propagating to the contact 20 through 21. Normally, the impedance of the piezoelectric vibrator 10 increases as the contact area between the piezoelectric vibrator 10 and the bulging portion 21 increases.

Next, a method for measuring pressure change in the treatment method of the present invention will be described.
In the treatment method of the present invention, a change in impedance of the piezoelectric vibrator 10 of the pressure vibrator 1 is calculated, and the change in impedance is converted into a change in pressure. This pressure change is a change in pressure applied to the measurement object contact surface 22 of the contact 20 of the pressure vibrating body 1. The measurement object contact surface 22 is in contact with the surface of the electrode 41 as described above. For this reason, a change in pressure applied to the measurement object contact surface 22 corresponds to a change in pressure generated by contact between the electrode 41 and the abnormal part. The change in pressure applied to the measurement object contact surface 22 is obtained by applying an AC voltage having a frequency corresponding to a resonance frequency unique to the piezoelectric vibrator to the piezoelectric vibrator 10 of the pressure vibrator 1. A step of taking a current from a piezoelectric vibrator in a vibration state; a change in a current value I of a current generated according to a pressure change applied to a measurement object contact surface 22 of the contact 20 and a piezoelectric It can be measured by a method including a step of calculating a change in impedance of the piezoelectric vibrator from a voltage value V of an alternating voltage applied to the vibrator; and a step of converting the change in impedance into a change in pressure. The current value I corresponds to the amount of electric energy flowing through the piezoelectric vibrator 10, and the voltage value V corresponds to the strength of the voltage applied to the piezoelectric vibrator 10.

FIG. 6 is a block diagram of a pressure measurement circuit that can be advantageously used to measure pressure changes in the treatment method of the present invention. The pressure measurement circuit 30 is inserted between a power source 31 that generates an AC voltage having a constant frequency, a voltmeter 32 for measuring a voltage value of a voltage generated between the lead wire 15a and the lead wire 15b, and the lead wire 15a. A resistor 33 (resistor: R), a voltmeter 34 for measuring the voltage value of the voltage generated at both ends of the resistor 33, and an arithmetic unit 35. The power source 31 generates an AC voltage having a frequency corresponding to the resonance frequency inherent in the pressure vibrating body 1 and applies the AC voltage to the piezoelectric vibrator via the lead wires 15a and 15b. When the piezoelectric vibrator has a disk shape, the resonance frequency is preferably a resonance frequency in the spread vibration mode. The frequency corresponding to the resonance frequency unique to the piezoelectric vibrator means a frequency in the range of resonance frequency ± 10%, preferably in the range of resonance frequency ± 5%. The frequency of the alternating voltage applied to the piezoelectric vibrator is generally in the range of 20 kHz to 10 MHz, preferably in the range of 20 kHz to 5 MHz, more preferably in the range of 20 kHz to 1 MHz, still more preferably in the range of 20 to 500 kHz, and particularly preferably 20. It is in the range of ~ 100 kHz. The voltage of the alternating voltage applied to the piezoelectric vibrator is generally 5 V or less, preferably 1 to 3 V in terms of effective value. The voltmeter 32 measures a voltage value of a voltage generated between the lead wire 15a and the lead wire 15b, that is, a voltage value V of a voltage applied to the piezoelectric vibrator. The voltmeter 34 measures the voltage value V ₂ of the voltage generated across the resistor 33. The arithmetic unit 35 calculates the current value I of the current from the formula: I = V ₂ / R. Then, from the obtained current value I and the voltage value V, the impedance Z of the piezoelectric vibrator is calculated from the formula: Z = V / I, and the change in the impedance Z is converted into the change in the pressure of the measurement target. . The period of pressure change of the measurement object can be converted from the period of impedance change. The period of the pressure change can be, for example, a time interval between adjacent peaks by detecting a plurality of impedance peaks that appear periodically on the graph when the impedance change is represented as a graph. The intensity of the pressure change of the measurement object can be converted from the height or depth of the impedance peak. The strength of the pressure change is, for example, when an impedance change is represented as a graph, an impedance peak periodically appearing on the graph is detected, and the difference in peak height or depth between adjacent peaks is detected. be able to. In addition, a calibration curve is prepared in advance by examining the relationship between the pressure value applied to the pressure vibrator and the impedance value of the piezoelectric vibrator when the pressure is applied, and the impedance of the piezoelectric vibrator and the calibration curve are From the above, the pressure applied to the pressure vibrating body may be calculated.

Next, the effect of the pressure vibrating body will be described.
FIG. 7 is a graph showing the change over time in the impedance of the piezoelectric vibrator, which was measured by bringing a pressure vibrator having a configuration usable in the treatment method of the present invention into contact with the abdominal surface of a human (subject). The graph of FIG. 7 shows a contact made of a nitrile rubber (bulb radius of curvature: 50 mm, diameter: 14.5 mm, thickness) at the center of an aluminum vibrator case (diameter: 14 mm, thickness: 3 mm). A piezoelectric vibrator when a pressure vibrating body having a configuration in which the tip of the bulging part of 9.8 mm) is in contact is brought into contact with the abdomen surface of the subject and an AC voltage having a frequency of 320 kHz is applied to the piezoelectric vibrator. This is a change with time in the impedance of the vibrator. The subject had a normal breath for 70 seconds from the start of the measurement, and then took a deep breath. As shown in this graph, the period of the impedance peak of the piezoelectric vibrator was 6 seconds from the start of measurement to 60 seconds. The period of this peak coincided with the subject's breathing period. The peak of impedance when the subject took a deep breath was clearly higher than the peak during normal breathing. That is, it can be seen from this result that it is possible to measure a rapid pressure change such as that caused by breathing by using the pressure oscillator. Furthermore, it can be seen that a slight difference in pressure such as a pressure generated by normal breathing and a pressure generated by deep breathing can be detected by using the pressure vibrating body.

  FIG. 8 is a graph showing the relationship between the pressure applied to the contact of the pressure vibrator having a configuration usable in the treatment method of the present invention and the impedance of the piezoelectric vibrator. The graph of FIG. 8 shows a piezoelectric vibrator of a pressure vibrator having a configuration in which the tip of the bulge portion of the contact is in contact with the center of an aluminum vibrator case (diameter: 14 mm, thickness: 3 mm). In addition, a change in impedance of the piezoelectric vibrator when a predetermined pressure is applied to the contact while applying an AC voltage having a frequency of 320 kHz is shown. A to D in FIG. 8 are data of a pressure vibrating body using contacts A to D having a configuration described in Table 1 below as the contacts, respectively. As shown in this graph, the amount of change in impedance of the piezoelectric vibrator with respect to the pressure applied to the contact varies greatly depending on the material and shape of the contact. That is, it can be seen from this graph that the dynamic range of the pressure change measured as the change in impedance of the piezoelectric vibrator of the pressure vibrating body can be adjusted by changing the configuration of the material and shape of the contact of the pressure vibrating body. From the above graph, the pressure vibrator contact is placed so that the measurement object contact surface of the contact is in contact with the surface of the detection / treatment means treatment, and the pressure generated by the contact between the detection / treatment means and a foreign object Is applied to the contact surface of the measurement object that is in contact with the contact detection / treatment means, and the bulging portion of the contact of the pressure vibrator is applied to the contact surface of the measurement object. The pressure vibrating body can be used as a pressure measurement means for a therapeutic instrument by forming it from an organic polymer elastic material with the physical properties that the contact area between the bulge of the contact and the piezoelectric vibrator changes according to the change. I understand.

Table 1
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shape
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Object contact at the bulging part Contact material Spherical radius of curvature Spherical radius of curvature Diameter Thickness ──────────────────────────── ────────────
A NBR (hardness 40 degrees) 50mm 50mm 14.5mm 9.8mm
B NBR (hardness 40 degrees) 20mm 50mm 14.5mm 9.8mm
C NBR (hardness 70 degrees) 20mm 50mm 14.5mm 9.8mm
D POM 50mm 50mm 14.5mm 9.8mm
────────────────────────────────────────
NBR: Nitrile rubber butadiene rubber, ie nitrile rubber POM: Polyoxymethylene, ie polyacetal resin

1 Pressure vibrator 2 Living body (myocardium)
DESCRIPTION OF SYMBOLS 10 Piezoelectric vibrator 11 Piezoelectric body 12 Electrode 12a Folding electrode 13 Electrode 14 Vibrator case 15a, 15b Lead wire 20 Contact 21 Expansion part 22 Measuring object contact surface 23 Flange part 30 Pressure measurement circuit 31 Power supply 32 Voltmeter 33 Resistance 34 Voltmeter 35 Computing Device 40 Flexible Tube 41 Electrode (Detection / Treatment Means)
42 Power cable 43 Contact holding plate 44 Power cable hole 45 Contact hole 46 Piezoelectric vibrator holding plate 47 Power cable hole 48 Vibrator hole 49 Lead wire hole

Claims (10)

A flexible tube, a detection / treatment means for detecting a physical or chemical foreign matter generated in a living body, and treating the foreign matter in contact with the foreign matter, provided at the distal end of the flexible tube; and A treatment tool including a pressure measurement means for measuring a pressure change caused by contact between the detection / treatment means and a foreign object in a flexible tube is prepared, and the treatment tool is prepared. The tip of the body is inserted into the living body, the foreign matter in the living body is detected by the detection / treatment means, and then the pressure change caused by the contact between the detection / treatment means and the foreign matter is measured by the pressure measurement means, and then the treatment means A therapeutic method for treating the foreign body,
The pressure measuring means includes a piezoelectric vibrator composed of a plate-like piezoelectric body and electrodes provided on both surfaces of the piezoelectric body, and a bulging portion on one surface, the bulging portion being the piezoelectric vibration. A disk-shaped contact element arranged in a state in which the surface opposite to the surface provided with the bulging portion is in contact with the surface of the detection / treatment means treatment while being in contact with the surface of one electrode of the child The bulging portion of the contact of the pressure vibrating body is generated by contact between the detection / treatment means and a foreign object, and is applied to the surface of the contact that contacts the detection / treatment means. Including a pressure vibrating body formed of an organic polymer elastic material having a physical property in which the contact area between the bulge portion of the contact and the piezoelectric vibrator changes in accordance with a change in pressure,
A method for measuring a pressure change caused by contact between a detection / treatment means and a foreign substance by an operation including the following steps:
Applying an alternating voltage having a frequency corresponding to the resonance frequency inherent to the piezoelectric vibrator to the piezoelectric vibrator of the pressure vibrator to bring the piezoelectric vibrator into a vibration state; a current from the piezoelectric vibrator in the vibration state From the change of the current value of the current generated according to the pressure change applied to the surface of the contactor in contact with the detection / treatment means and the voltage value of the AC voltage applied to the piezoelectric vibrator. Calculating a change in impedance of the vibrator; and converting the change in impedance into a change in pressure.   The method according to claim 1, wherein measurement of a pressure change caused by contact between the detection / treatment unit and the foreign substance by the pressure measurement unit is continued until the treatment of the foreign substance by the treatment unit is completed.   The method according to claim 1, further comprising the step of calculating a volume of the foreign matter from a pressure change generated by contact between the detection / treatment means and the foreign matter by the pressure measuring means.   The method according to claim 1, wherein the foreign substance is an abnormal site formed in the myocardium.   The treatment method according to claim 1, wherein the piezoelectric body has a disk shape.   The method according to claim 1, wherein the contact has a disk shape in which a bulge is formed on one surface.   The contactor diameter / thickness ratio is in the range of 1: 5 to 1: 1/5, provided that the contactor thickness is opposite to the surface provided with the bulge from the tip of the bulge. 2. A method according to claim 1, which means the thickness to the side surface.   The method according to claim 1, wherein the bulging portion of the contact is hemispherical.   The method according to claim 1, wherein the entire contact is formed of an organic polymer elastic material.   Flexible tube, detection / treatment means for detecting a physical or chemical foreign matter generated in the living body and treating the foreign matter in contact with the foreign matter, provided at the tip of the flexible tube, a disk shape A piezoelectric vibrator comprising a piezoelectric body and electrodes provided on both surfaces of the piezoelectric body, and a bulge portion on one surface, the bulge section being a surface of one electrode of the piezoelectric vibrator A pressure oscillator including a disk-shaped contact element disposed in a state in which the surface opposite to the surface provided with the bulging portion is in contact with the surface of the detection / treatment means treatment, The bulging portion of the contact of the pressure vibrating body is generated by the contact between the detection / treatment means and the foreign matter, and the contact according to the pressure change applied to the surface of the contact that contacts the detection / treatment means. Organic polymers with physical properties that change the contact area between the swollen part of the ceramic and the piezoelectric vibrator Means for bringing a piezoelectric vibrator into a vibrating state by applying an AC voltage having a frequency corresponding to a resonance frequency unique to the piezoelectric vibrator to a piezoelectric vibrator of a pressure vibrator made of a conductive material; Means for extracting a current from a piezoelectric vibrator in a state; means for calculating a change in impedance of the piezoelectric vibrator from a change in the current value of the current and a voltage value of an AC voltage applied to the piezoelectric vibrator; and a change in the impedance A treatment tool including means for converting the pressure into a change in pressure.

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