WO2012053531A1 - Internal diameter examination device, electrical measurement sensor, and production method for electrical measurement sensor - Google Patents

Abstract

[Problem] To provide an internal diameter examination device which can with a comparatively simple configuration simply and rapidly examine the status of a space to be examined, an electrical measurement sensor, and a production method for the electrical measurement sensor. [Solution] An internal diameter examination device comprising: an electrical measurement sensor inserted into a space to be examined that is filled with a conductive solution; a current supply source; and a voltage detection means. The electrical measurement sensor has: an insulating case with at least a surface thereof that comprises an insulating material and is substantially cylindrical; two current electrodes formed at a position separated from the axial direction of the cylindrical shape of the surface of the insulating case; three or more voltage detection electrodes formed between the two current electrodes on the surface of the insulating case; a conductive cable connected to the two current electrodes and the three or more voltage electrodes and which conducts to the outside; and a sheath that encloses the cable. The current supply source and the voltage detection means detect the current between the two current electrodes and the two or more voltages generated at the three or more voltage detection electrodes, via the conductive cable.

Description

Inner diameter inspection device, electric measurement sensor, and method of manufacturing electric measurement sensor

The present invention relates to an inner diameter inspection device, an electric measurement sensor, and a method for manufacturing the electric measurement sensor.

Cerebral infarction or ischemic myocardial infarction is caused by a decrease in blood flow due to a vascular stenosis in an artery, cerebral blood vessel, or coronary artery. The blood vessel stenosis is formed by the adhesion of a thrombus inside the blood vessel or the growth of plaque on the blood vessel wall. Plaque growth in the artery causes arteriosclerosis. As a method for diagnosing thrombus or plaque, there is an angiography test. This is a test in which a thin tube (catheter) is inserted into a blood vessel and the state of the contrast medium injected through this catheter is observed. The catheter is usually inserted into the blood vessel near the base of the patient's foot. After feeding the catheter until the tip of the catheter reaches the target site, the contrast medium is injected into the target site via the catheter. Since the contrast agent has an X-ray shielding effect, a shadow of a blood vessel at a target site is grasped as an image in an image obtained by X-ray imaging. From this image, a stenosis portion of a blood vessel is detected as a narrow portion of a blood flow channel.

When a stenosis is detected, a stent is attached as one of the treatment means. The stent is a tube having a metal network structure. The diameter of the stent can be changed. The stent is attached to the balloon catheter with its diameter reduced, and is sent to the stenosis portion together with the balloon catheter. Then, the diameter of the stent is expanded by inflating the balloon at the narrowed portion. As a result, the blood vessel is expanded and supported by the stent so as to maintain the state. In this case, it is necessary to attach the stent to a place where the stenosis of the blood vessel exists. After the stent mounting operation is completed, an angiographic examination is performed again, and the obtained blood vessel image is compared with the blood vessel image obtained before the operation to confirm whether or not the stent has been correctly mounted. That is, the blood flow channel of the stenosis before surgery has recovered to the same channel width as the blood flow channels of other blood vessels, so that the stent has been mounted normally and the blood flow state is Check that it has recovered normally.

Examples of the blood vessel contrast agent include a nonionic water-soluble iodine contrast agent, a water-soluble iodine contrast agent, and a low osmotic water-soluble iodine contrast agent. These contrast agents may be a burden on the patient's body. The causes of this burden are roughly divided into four categories: (1) physical properties of contrast agents, (2) chemical toxicity of contrast agents, (3) anaphylaxis-like reactions, and (4) psychological factors. (1) and (2) are dose-dependent reactions involving the hyperosmolarity, non-hydrophilicity, and ion loading of contrast agents. (3) is a non-dose-dependent allergic reaction such as release of chemical mediators and activating effects such as antigen-antibody reaction. (3) is particularly a burden that adversely affects kidney function. Each symptom of side effects that occur during treatment is a combination of various factors. For example, sneezing, rash (urticaria), heat sensation, vascular pain, vomiting, cold sweat, facial pallor, hypotension, or dyspnea may occur. Due to these side effects, the amount of angiographic contrast agent that can be used in one operation and the time of use are limited. As a result, it may be difficult to sufficiently confirm the completion of stent mounting from the detection of the vascular stenosis. This causes the need to reinsert the stent later.

On the other hand, X-ray projection is always performed when checking for the presence or absence of a stenosis and when confirming the completion of stent placement. Therefore, during that time, both the doctor and the patient may be exposed to X-rays.

In addition, the blood vessel images obtained by angiography examinations show a clear position of the vascular stenosis due to the continuous change of the blood vessel position due to the heartbeat, blurring of the image due to non-focus diffraction, loss of transport of the contrast agent in the blood vessel, etc. Confirmation is difficult. Also, for the same reasons, it is difficult to correctly determine the position of the attached stent. Under such circumstances, it is very difficult to mount an appropriate stent, and there are many cases in which a subsequent stent is reinserted. However, once a stent is mounted, it is difficult to remove it, so the number of treatments with the stent is limited.

Also, as a case other than the constricted portion of the blood vessel, the piping may be clogged due to, for example, calcium deposition in the plastic water piping or deposition of residues in the drainage in the sewer piping. Such clogging cannot use X-rays or X-ray contrast media depending on the location of the piping, and it is extremely difficult to detect the site.

As a technique for detecting plaque and thrombus without using angiographic examination, Patent Document 1 discloses a position and posture sensor using an electromagnetic pulse (EMP) and an intravascular ultrasonic examination (IVUS: intravascular ultrasound). And a medical system that combines optical coherence tomography (OCT: Optical Coherence Tomography) has been proposed. Details of the position and orientation sensors used in Patent Document 1 are disclosed in Patent Document 2. However, the sensor described in Patent Document 2 needs to generate a three-dimensional electromagnetic field, and also requires image processing. In addition, the apparatus described in Patent Document 1 in which IVUS or OCT is combined with such a sensor requires considerable calculation processing even with image processing alone, takes time for judgment, and says that confirmation of stent attachment cannot be performed quickly. There is also a problem. Therefore, a simple inner diameter inspection device has been desired for detecting clogging of piping.

JP 2006-346468 A US Pat. No. 6,233,476

The present invention has been made in consideration of the above circumstances, and can quickly make an inspection decision without using X-rays, and can inspect the state of the inspection object space with a relatively simple configuration. An object is to provide an inner diameter inspection device, an electric measurement sensor, and a method for manufacturing the electric measurement sensor.

According to the first aspect of the present invention, an electrical measurement sensor that is inserted into a space to be inspected filled with a conductive solution, a current supply source that supplies current to the electrical measurement sensor, and a voltage of the electrical measurement sensor are detected. An electrical measurement sensor at least at a surface made of an insulating material and having a substantially cylindrical shape, and a cylindrical shape on the surface of the insulation housing at a position separated in the axial direction. It is connected to two formed current electrodes, three or more voltage detection electrodes formed between two current electrodes on the surface of the insulating housing, two current electrodes and three or more voltage detection electrodes. A conductive cable led out of the inspection target space and a sheath enclosing the conductive cable, the current supply source is connected between the two current electrodes via the conductive cable, and the voltage detection means is connected to the inspection target space. Depending on the inner diameter of An inner diameter inspection characterized by being connected to three or more voltage detection electrodes via a cable so as to detect two or more voltages generated between three or more voltage detection electrodes. An apparatus is provided.

The voltage detection means may include a voltage measuring device that measures a voltage for each electrode set including two adjacent electrodes among the voltage detection electrodes. Alternatively, the voltage detection means may include a voltage measuring device that measures the voltage of an electrode set in which one electrode is shared for every two adjacent electrodes among the voltage detection electrodes.

The current supply source is an alternating current source, and the voltage detection means includes a transformer that receives two or more voltages and performs electrical insulation and voltage conversion, a voltage amplifier that amplifies the output voltage of the transformer, and the voltage amplifier And a detector for detecting the output of. In this configuration, it is desirable that a capacitor that cuts off low-frequency noise is inserted between the voltage detection electrode that is a voltage detection target when viewed from the voltage detection means and the transformer.

Corresponds to two or more voltage values from the current measuring means for measuring the current supplied from the current supply source to the current electrode, the two or more voltage values obtained by the voltage detecting means and the current value obtained by the current measuring means. It is desirable to further include a calculation unit that calculates two or more apparent resistance values and an image generation unit that generates an image in which the two or more apparent resistance values are arranged.

The image generating means generates a resistance comparison image that can compare the magnitude relationship between two or more apparent resistance values in correspondence with the positions of three or more voltage detection electrodes, and the embolized portion that occurs in the space area to be inspected. This can be shown by the resistance comparison image.

When the image generating means processes the two apparent resistance values calculated by the calculating means, two apparent resistances for two electrode sets that give two apparent resistance values among three or more voltage detection electrodes. The electrical measurement sensor moves in the direction of the electrode set that gives a relatively large resistance value, and after the apparent resistance value of the electrode set reaches the maximum value, the two apparent resistance values become equal. Sometimes, a resistance comparison image can be generated assuming that a constriction exists at the midpoint between the two electrode sets. Separately from this, when the image generating means processes three apparent resistance values calculated by the calculating means, three electrode sets that give three apparent resistance values among four or more voltage detection electrodes. After the electric measurement sensor moves in the direction of the electrode set that gives a relatively large resistance value among the three apparent resistance values, and the apparent resistance value of the electrode set reaches the maximum value, the three electrode sets When the apparent resistance value required for the central electrode group is the maximum, a resistance value comparison image can be generated assuming that a constriction exists at the midpoint of the central electrode group.

The insulating housing of the electrical measurement sensor is provided with a balloon that is inflated or deflated by a gas or liquid supplied through a pipe, and the image generating means displays a resistance value comparison image of the embolized portion generated in the space to be inspected. By indicating by, it is possible to indicate the position where the balloon should be inflated or deflated.

The stent is attached to the balloon which can be expanded beyond the elastic limit by inflating the balloon. The image generating means shows the position of the embolized portion of the blood vessel to which the stent is to be attached by showing the embolized portion generated in the space area to be examined by the resistance value comparison image in a state where the electrical measurement sensor is inserted into the blood vessel. Can show.

The voltage value of 2 or more changes according to the influence of the conductivity of the space to be inspected, and the image generation unit associates the magnitude relationship of the apparent resistance values of 2 or more with the position of the voltage detection electrode of 3 or more. It is also possible to generate a resistance value comparison image that can be compared, and to show a portion having a different conductivity from the other portion of the inspection target space by the resistance value comparison image.

When the space to be inspected is a blood vessel having a stent mounted therein, the image generation means, when processing two apparent resistance values calculated by the calculation means, two of the three or more voltage detection electrodes are used. With respect to two electrode sets that give an apparent resistance value, the electric measurement sensor moves in the direction of the electrode set that gives a relatively small resistance value out of the two apparent resistance values, and the apparent resistance value of the electrode set is minimum. When the two apparent resistance values become equal after reaching the value, the resistance value comparison image can be generated assuming that a stent exists at the midpoint between the two electrode sets.

When the examination target space is a blood vessel having a stent mounted therein, the display processing means, when processing the three apparent resistance values calculated by the calculation means, three of the four or more voltage detection electrodes are used. For the three electrode sets that give an apparent resistance value, the electric measurement sensor moves in the direction of the electrode set that gives a relatively small resistance value among the three apparent resistance values, and the apparent resistance value of the electrode set is minimum. When the apparent resistance value required for the center electrode group of the three electrode sets becomes the minimum after the value is reached, it is assumed that the stent is attached to the middle point of the center electrode group. A comparison image can be generated.

According to the second aspect of the present invention, at least the surface is made of an insulating material and has a substantially cylindrical shape, and the surface of the insulating case is formed at a position separated from the cylindrical shape in the axial direction. Current is supplied between two current electrodes, three or more voltage detection electrodes formed between the two current electrodes on the surface of the insulating housing, and two current electrodes from the outside, and three or more voltages are supplied. An electrical measurement sensor is provided, comprising: a conductive cable that extracts two or more voltages generated between the detection electrodes to the outside; and a sheath that encloses the conductive cable.

One of the two current electrodes can be configured to be formed at the tip of the insulating casing opposite to the side where the conductive cable of the insulating casing is attached. Further, a plurality of electrode groups including two current electrodes and three or more voltage detection electrodes may be formed in the axial direction of the insulating housing. Further, in addition to the two current electrodes, a configuration in which a third current electrode is formed between the two current electrodes and at a position between each of the two current electrodes and sandwiching the voltage detection electrode, You can also

The at least part of the two current electrodes and the three or more voltage detection electrodes may be formed of a metal electrode member. In this case, the metal electrode member may be embedded in the insulating casing to form a surface that is substantially the same as the surface of the insulating casing.

At least a part of the two current electrodes and the three or more voltage detection electrodes may be formed by winding a conductive wire constituting the conductive cable around the surface of the insulating housing. In this case, the conductive wires forming at least a part of the two current electrodes and the three or more voltage detection electrodes are embedded in the insulating casing to form a surface substantially the same as the surface of the insulating casing. It can be configured.

At least a part of the two current electrodes and the three or more voltage detection electrodes can be configured such that the end surfaces of the conductive wires constituting the conductive cable are exposed on the surface of the insulating housing.

It can be configured that the sheath is integrated with the insulating housing. Further, the insulating casing can be configured such that the inside is filled with an insulating material different from that of the insulating casing. The insulating casing may be provided with a balloon that is inflated or deflated by a gas or liquid supplied via a pipe.

According to the third aspect of the present invention, as a method of manufacturing the above-described electrical measurement sensor, the insulating casing is heat-softening resinous, and is positioned at a position away from one electrode in the axial direction of the insulating casing. A first step of providing the first and second holes, and a corresponding conductive wire of the conductive cable is drawn out from the first hole to the outside, and the drawn conductive wire is insulated to the position where the second hole is blocked. A second step of winding a portion of the body around the body, and a third step of fixing the conductive wire after securing the electrical connection with the conductive wire by inserting a conductive first fixing means into the first opening. A step of connecting the conductive second fixing means to the end of the conductive wire wound in the second step and fixing the conductive wire in a tensioned state; and a first fixing The conductive wire is insulated by passing an electric current between the means and the second fixing means to heat the conductive wire therebetween. A fifth step of embedding, and a sixth step of removing the side to which the second fixing means of the conductive wire is connected from the second fixing means and inserting it into the second opening. A method for manufacturing an electrical measurement sensor is provided.

According to the present invention, it is possible to inspect the state of the inspection object space with a relatively simple configuration. For example, when examining a blood vessel, plaque, thrombus, or stent can be detected without using a tube contrast examination. Further, even when the inspection target is a water pipe or a sewer pipe, there is no mechanism portion and the handling is easy, and a clogged portion of these pipes can be easily detected.

It is a figure which shows the structure of the internal diameter test | inspection apparatus which concerns on embodiment of this invention, and while showing the structure and usage form of an electric measurement sensor simplified, it is a block structure of the electric measuring device which measures using this electric measurement sensor Indicates. It is a figure which shows the structural example of the well-known electrical conductivity sensor which measures the electrical conduction of the solution which has electroconductivity. FIG. 3 is a diagram for briefly explaining the principle of measurement of electrical conductivity by the electrical conductivity sensor shown in FIG. 2, showing a simplified cross-sectional view of the electrical conductivity sensor, and an electrical measuring unit connected to the electrical conductivity sensor A simple configuration example is shown. FIG. 4 is a diagram for quantitatively explaining in detail the measurement principle by the electrical conductivity sensor shown in FIGS. 2 and 3. It is explanatory drawing for carrying out quantitative examination, and shows one model structure of an electric measurement sensor. It is a figure explaining the electrical phenomenon in the model shown in FIG. 5, and is a figure explaining the spatial distribution of the current line between current electrodes. It is a figure explaining the electrical phenomenon in the model shown in FIG. 5, and is a figure explaining the spatial distribution of the current line between current electrodes. It is a figure which shows the behavior of the change of the apparent resistance value in a model analysis result. It is a figure which shows the behavior of the change of the apparent resistance value in a model analysis result. It is a figure explaining the structural example of the electric caliper used as an electric measurement sensor in the internal diameter measuring apparatus shown in FIG. It is a figure which shows the electric caliper of a structure different from the electric caliper shown in FIG. It is a figure explaining the structure of the electric caliper which is a modification of the electric caliper shown in FIG. It is a figure explaining the connection form of each electrode of the electric caliper each shown in FIGS. 10-12, and the electrical measurement part in the internal diameter test | inspection apparatus shown in FIG. It is a figure explaining the connection form of each electrode and the electric measurement part in the internal diameter test | inspection apparatus shown in FIG. 1 about the electric caliper from which the number of voltage detection electrodes differs from what is shown in FIGS. It is a figure explaining the connection form of each electrode and the electric measurement part in the internal diameter test | inspection apparatus shown in FIG. 1 about the electric caliper from which the number of voltage detection electrodes differs from what is shown in FIGS. It is a figure explaining the connection form of each electrode and the electrical measurement part in the internal diameter test | inspection apparatus shown in FIG. 1 about the electric caliper from which a voltage detection electrode differs further. It is a figure explaining the connection form of each electrode and the electrical measurement part in the internal diameter test | inspection apparatus shown in FIG. 1 about the electric caliper from which a voltage detection electrode differs further. It is a figure explaining the structure of the electric caliper of a structure further different from what was shown in FIG. It is a figure explaining the spatial distribution of the electric current produced | generated by the electric caliper shown in FIG. It is a figure explaining the structure and each electrode of an electric caliper of a structure further different from the electric caliper shown in FIG. 10 thru | or FIG. It is a figure explaining the connection form of each electrode of the electric caliper shown in FIG. 20, and the electric measurement part in the internal diameter test | inspection apparatus shown in FIG. It is a figure explaining the structure of what becomes a modification of the electric caliper shown in FIG. 20 and FIG. It is a figure explaining the connection form of each electrode of the electric caliper shown in FIG. 22, and the electric measurement part in the internal diameter test | inspection apparatus shown in FIG. It is a figure which shows the structural example of the current power supply circuit used as a current power supply. It is a figure which shows the structural example of the voltage measuring device circuit used as a voltage measuring device. It is a figure which shows the structural example of another voltage measuring device circuit used as a voltage measuring device. It is a figure which shows the structural example of the circuit used as a detector in the voltage measuring device circuit of FIG. It is a figure which shows an example of the resistance value comparison image by two apparent resistance values. It is a figure which shows an example of the resistance value comparison image by three apparent resistance values. It is a figure which shows an example of the resistance value comparison image by two apparent resistance values. It is a figure which shows an example of the resistance value comparison image by three apparent resistance values. It is a figure explaining the structural example of the electric caliper balloon catheter used as an electric measurement sensor in the internal diameter measuring apparatus shown in FIG. It is a figure which shows an example of the electrode structure in an electric caliper or an electric caliper balloon catheter. It is a figure which shows the manufacturing method of a buried electrode electric caliper. It is a figure which shows the manufacturing method of a buried electrode electric caliper, and demonstrates the process following the process shown in FIG. It is a figure which shows the electrode structure in a buried electrode electric caliper.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[overall structure]
FIG. 1 is a diagram showing a configuration of an inner diameter inspection apparatus according to an embodiment of the present invention. The structure and usage of an electric measurement sensor 1010 are simplified and measurement is performed using the electric measurement sensor 1010. The block structure of the electric measurement part 1020 is shown. FIG. 1 also shows a display device 1030 connected to the electrical measurement unit 1020.

This inner diameter inspection apparatus includes an electric measurement sensor 1010 inserted into an inspection target space 1000 (for example, inside a blood vessel) filled with a conductive solution, and an electric measurement unit 1020 connected to the electric measurement sensor 1010. A display device 1030 is connected to the electrical measurement unit 1020.

The electrical measurement sensor 1010 includes an insulating housing 1011 having at least a surface made of an insulating material and having a substantially cylindrical shape. Two current electrodes 1012 and 1013 are formed at positions on the surface of the insulating housing 1011 that are separated from each other in the cylindrical axial direction. Between the two current electrodes 1012 and 1013 on the surface of the insulating edge housing 1011, three or more (three in FIG. 1) voltage detection electrodes 1014, 1015 and 1016 are formed. The electrical measurement sensor 1010 also includes a conductive wire 1017 that connects the current electrodes 1012 and 1013 and the voltage detection electrodes 1014, 1015, and 1016 to the electrical measurement unit outside the inspection target space 1000, and an external lead-out cable 1019 that bundles them together. Prepare. External lead-out cable 1019 is enclosed in external lead-out cable sheath 1018.

The electrical measurement unit 1020 includes a current supply source 1021 that supplies current to the electrical measurement sensor 1010 and a voltage detection unit 1022 that detects the voltage of the electrical measurement sensor 1010. The current supply source 1021 is connected to the two current electrodes 1012 and 1013 via the external lead-out cable 1019. The voltage detection unit 1022 is a voltage that changes according to the size of the inner diameter of the space to be inspected 1000 and the electrical characteristics, and is generated between three or more voltage detection electrodes 1014, 1015, 1016 (2 in this case). Are connected to three or more voltage detection electrodes 1014, 1015, 1016 via an external lead-out cable 1019.

The electrical measurement unit 1020 also includes a digital / analog converter (A / D) 1023, an arithmetic processing unit 1024, and an image generation processing unit 1025. The current supply source 1021 has current measuring means (not shown) for measuring the current supplied to the current electrodes 1012 and 1013, and the digital / analog converter (A / D) 1023 is obtained by the voltage detection unit stage 1022. The two or more analog voltage values obtained and the analog current value obtained by the current measuring means are each converted into a digital signal. The arithmetic processing unit 1024 outputs two or more apparent values corresponding to two or more voltage values V1, V2,..., Vm (m = 2 in the example of FIG. 1) from the output of the digital / analog converter (A / D) 1023. , Rm (m = 2 in the example of FIG. 1). The image generation processing unit 1025 generates an image in which two or more apparent resistance values R1, R2,. This image is displayed on the display device 1030.

As the arithmetic processing unit 1024 and the image generation processing unit 1025, for example, a personal computer can be used. That is, by using a personal computer equipped with hardware such as a CPU, RAM, ROM, hard disk, and various interfaces, and installing a computer program that operates under a predetermined operating system, the arithmetic processing unit 1024 and the image generation processing unit 1025 functions can be realized.

[Explanation of measurement principle]
2. Description of the Related Art Conventionally, an electrical conductivity sensor used in a conductivity meter is well known as a sensor for measuring the electrical conductivity of a conductive solution. This electrical conductivity sensor includes a pair of current electrodes provided on the surface of an insulating casing in a protective pipe and a pair of voltage detection electrodes (generally used) formed between the current electrodes. Are also referred to as “voltage electrodes”). Based on the measurement principle of the electrical conductivity sensor having such a structure, the measurement principle using the electrical measurement sensor 1010 shown in FIG. 1 will be described.

FIG. 2 is a diagram showing a configuration example of a known electrical conductivity sensor 100 that measures the electrical conductivity of a conductive solution.

The electrical conductivity sensor 100 includes an insulating housing 1 having at least a surface made of an insulating material or entirely made of an insulating material, and surrounds the outer periphery of the insulating housing 1 to have an electrically insulating protective pipe 2. Is provided. The protective pipe 2 is attached to the insulating housing 1 via the engaging portion 3. The insulating housing 1 is provided with a pair of current electrodes 5 and 6, and a pair of voltage detection electrodes 7 and 8 are provided between the pair of current electrodes 5 and 6. The protective pipe 2 is provided with an opening 9 that eliminates air bubbles and allows an external solution to freely enter and exit. External lead-out cables (not shown) connected to the current electrodes 5 and 6 and the voltage detection electrodes 7 and 8 are sealed in the external lead-out cable sheath 4 from the insulating housing 1 and are connected to the external electrical measuring unit 30 ( (See FIG. 3).

FIG. 3 is a diagram for briefly explaining the principle of measurement of electrical conductivity by the electrical conductivity sensor 100 shown in FIG. 2, and a simplified cross-sectional view of the electrical conductivity sensor 100 is shown. The simple structural example of the electric measurement part 30 connected to is shown.

The electrical measuring unit 30 includes a current power source 31 and a voltage measuring device 32. A current power source 31 is connected to the pair of current electrodes 5 and 6 of the electrical conductivity sensor 100. A voltage measuring device 32 is provided on the voltage detection electrodes 7 and 8. A current I (ampere) is supplied from the current power supply 31, and a potential difference V (volt) between the voltage detection electrodes 7 and 8 appears in the voltage measuring device 32 connected to the voltage detection electrode. The electric conductivity ρ of the solution 11 in the protective pipe 2 to be measured by the electric conductivity sensor 100 is obtained by the following equation.

Here, S is a spatial factor called a cell constant, which is a coefficient corresponding to a value obtained by dividing the current distribution in the solution, that is, the cross-sectional area through which the current flows by the distance through which the current flows. If the physical shape of the electrical conductivity sensor 100 is determined and the cell constant is determined, the electrical conductivity of the solution 11 is determined from the current I (ampere) and the potential difference V (volt) between the voltage detection electrodes 7 and 8. it can. This is the principle of the known electrical conductivity sensor 100.

FIG. 4 is a diagram for quantitatively explaining in detail the measurement principle by the electric conductivity sensor 100 shown in FIGS.

Suppose that the radius of the insulating housing 1 is r0. The insulating casing 1 having the radius r0 is provided with current electrodes 5 and 6 and voltage detection electrodes 7 and 8 whose surfaces have the same radius. A current power source 31 is connected to the current electrodes 5 and 6 via a conductive cable 21. A current I flows through the conductive cable 21. A current flows between the current electrodes 5 and 6 via the solution 11. The current density is J. A voltage measuring device 32 is connected to the voltage detection electrodes 7 and 8 via a conductive cable 23.

At this time, a potential difference Vm is generated between the voltage detection electrodes 7 and 8 due to the current flowing through the solution 11 in the protective pipe 2 (its current density is J) and the electrical conductivity of the solution 11. The voltage measuring device 32 detects the potential difference Vm between the voltage detection electrodes 7 and 8. At this time, the spatial average current density is

It becomes. Here, re is the radius of the effective spatial distribution (distance from the center line of the insulating housing 1) where the current obtained when the distribution of the current J is assumed to be uniform. In this case, the effective potential difference Vm between the voltage detection electrodes 7 and 8 depends on the spatial average current density given by the equation (2).

Given in. Here, d is the distance between the voltage detection electrodes. Then, the apparent resistance Ra is

It becomes. The cell constant S is

It becomes. Therefore, when the apparent resistance Ra is expressed using the cell constant S,

It becomes.

From the equation (6), it can be seen that the apparent resistance depends on the cell constant S. On the other hand, the cell constant S depends on the spatial distribution of current. Therefore, when the insulating housing 1, the current electrodes 5, 6 and the voltage detection electrodes 7, 8 are placed in a cylindrical space narrower than the effective spatial distribution in the protective pipe 2, for example, from the center line of the insulating housing 1 The apparent resistance Rn when the radius rn of the cylinder of r0 <rn <re is

It becomes. That is, when the insulating casing 1, the current electrodes 5 and 6, and the voltage detection electrodes 7 and 8 are placed in a cylindrical space narrower than the protective pipe 2, the resistance between the voltage detection electrodes 7 and 8 increases. .

As described above, the known electrical conductivity sensor 100 shown in FIGS. 2 to 4 includes the insulating housing 1, the current electrodes 5 and 6, and the voltage detection electrodes 7 and 8 in the protective pipe 2. The electrical conductivity of the solution 11 in the protective pipe 2 can be measured. In other words, the electrical conductivity cannot be measured unless it is in a fixed space called the protective pipe 2. On the other hand, the electrical measurement sensor 1010 according to the present invention shown in FIG. 1 is fundamentally different in that the protective pipe 2 in the electrical conductivity sensor 100 shown in FIGS. 2 to 3 is not provided. It has a structure, and the effect that the apparent resistance value depends on the surrounding space is utilized from the structure. The electric measurement sensor 1010 is hereinafter also referred to as “electric caliper” in the sense of measuring the inner diameter of the inspection target space. Hereinafter, the spatial dependence of the apparent resistance value in the electric measurement sensor 1010 will be quantitatively described.

FIG. 5 is an explanatory diagram for conducting a quantitative study, and shows one model structure of the electric measurement sensor 1010. The insulating housing 1011 of the electric measurement sensor 1010 has at least a surface made of an insulating material or entirely made of an insulating material and has a cylindrical shape, and current electrodes 1012 and 1013 are formed on the surface. Since the purpose is to explain the principle and effect, the voltage detection electrodes 1014, 1015, 1016, the conductive wires 1017, the external lead-out cable sheath 1018, the external lead-out cable and 1019 are omitted in FIG.

An electric measuring sensor 1010 is placed in an outer insulating wall 12 having a cylindrical shape and made of an electrically insulating material, and the inside of the outer insulating wall 12 is filled with a conductive solution 11. Consider the model that is. The outer insulating wall 12 is partially narrowed, and the solution region in that portion is referred to as “region“ 2 ””. The portion of the solution that is not narrowed is referred to as “region“ 1 ””. A transition area from the area “1” to the area “2” is defined as “area“ 3 ””. The radius of the insulating housing 1011 is r0, and the radii of the external insulating walls of the region “1” and the region “2” are rb and rt, respectively. The radius of the outer insulating wall of the region “3” is given by rd (x).

In such a model, in order to obtain the potential difference between the voltage detection electrodes 1014, 1015 and 1016 placed between the current electrodes 1012 and 1013, the current density in the space filled with the solution 11 is J.

The distribution of the current density J satisfying the above is obtained, and thereafter, the potential difference Vm between the voltage detection electrodes 1014, 1015, 1016 is obtained from the equation (3). Here, A represents the surface area of the current electrodes 1012 and 1013.

For the current density J of Equation (8), a general analytical solution cannot be obtained for the general space shape parameter based on the shape of FIG. Therefore, in order to make a quantitative examination, the current density in the direction along the longitudinal direction of the insulating housing 1011 is approximated as follows.

This approximation is applied to the current density at a position away from the current electrodes 1012 and 1013.

6 and 7 are diagrams for explaining the validity of the model shown in FIG. 5 and for explaining the spatial distribution of current lines between the current electrodes 1012 and 1013. FIG.

In the vicinity of the current electrode 1012 or 1013, as shown in FIG. 6, the radial component Jr is quite large and cannot be ignored.

On the other hand, in a place away from the current electrodes 1012 and 1013, as shown in FIGS. 6 and 7, the longitudinal component Jx from one current electrode 1012 or 1013 to the other current electrode 1013 or 1012 is dominant as the current density. To do. The radial component of the electric field when the cylindrical charge is placed in free space shows a radial dependence of r−1 by Gauss's electric field continuity principle. In this model, the radial electric field is caused by the external insulating wall 12. Is restricted by the law of conservation. That is, when the radial dependence of the electric field is rn, the radial dependence coefficient n is in a range smaller than 1, which is a value in the free section, that is, 0 <n <1. From this Gauss's law and the electric field conservation law, equation (9) is a reasonable approximation.

Next, specifically, the spatial current density Jx along the insulating casing 1011 is obtained by approximation based on Expression (9). Assuming that the current densities in the regions “1”, “2”, and “3” are J1 (x, r), J2 (x, r), and J3 (x, r), the current densities in the respective regions are as described above. By approximation, it can be essentially expressed as:

Here, J1, J2, and J30 (x) are amounts that determine the absolute value of the current density. Based on the current continuity principle and the current conservation law, the current density of region "1" and region "2"

It becomes. Than this

Is obtained. Here, rd indicates the radius of the outer insulating wall 12 from the central axis of the insulating casing 1011 with respect to the position in the longitudinal direction of the insulating casing 1011 in the region “3”.

Next, two voltage detection electrodes in each of the regions “1”, “2”, and “3” (not shown in FIG. 5 and any two electrodes of voltage detection electrodes 1014 to 1016 in FIG. 1 are assumed) Consider the magnitude of potential differences Vm1, Vm2, and Vm3 that occur between them. Here, d is an electrical separation distance between the two voltage detection electrodes. The result is

It becomes. Vm3 cannot be expressed explicitly using a primary function for a real number n. However, for an integer of n = 0, 1, it is obtained as follows.

In equation (13c), approximate calculation was performed using d << ld. Here, x0 represents the distance from the boundary position with the region “2” in the region “3”. Therefore, the value is in the range of 0 ≦ x0 ≦ ld−d.

In the measurement of the potential differences Vm1, Vm2, and Vm3, all voltage values depend on the current I supplied from the current electrodes 1012 and 1013. Therefore, at this point, the potential differences Vm1, Vm2, and Vm3 are mutually dependent. Therefore, not the potential differences Vm1, Vm2, and Vm3, but apparent resistance values obtained by dividing these by the current value I correspond to the diameters of the respective regions. Therefore, actual measurement evaluation is performed based on the apparent resistance values Rm1, Rm2, and Rm3. Each value is calculated from the equations (13a), (13b), and (13c).

It becomes.

8 and 9 show the behavior of changes in the apparent resistance values Rm1, Rm2, and Rm3 in the above model analysis results. That is, FIG. 8 shows how the apparent resistance values Rm1, Rm2, and Rm3 change in the range of rt from r0 to rb with respect to n = 1. FIG. 9 shows how the apparent resistance values Rm1, Rm2, and Rm3 change in the range of rt from r0 to rb with respect to n = 0.

The apparent resistance value Rm1 is obtained from the potential difference with respect to the radius rb of the constant external insulating wall 12. In this example, since rt is different and rb is constant, the apparent resistance value Rm1 is different from rt. It is the same. The apparent resistance value Rm2 is a value in the narrowed region “2” of the outer insulating wall 12, and the radius of the outer insulating wall 12 is rt. Therefore, when the radius rt is different, the apparent resistance value Rm2 changes greatly. The apparent resistance value Rm3 is a value in a transition region between the region “1” of the external insulating wall 12 having a constant radius and the region “2” of the external insulating wall 12 having a narrow radius. As a matter of course, the apparent resistance value Rm3 shows an intermediate change between the apparent resistance value Rm1 and the apparent resistance value Rm2. Changes in the actual apparent resistance values Rm1, Rm2, and Rm3 with respect to changes in the radius rt indicate intermediate changes between n = 0 and n = 1. In any case, it can be seen that the apparent resistance value Rm2 greatly changes with the change in the radius rt. The apparent relationship between the resistance values Rm1, Rm2, and Rm3 is always

It becomes.

Based on this relationship, at least two sets of voltage detection electrodes 1014, 1015, 1015, and 1016 are provided in the insulating housing 1011, and a potential difference detected between the voltage detection electrodes of each set is measured, thereby obtaining an apparent resistance value. In comparison, it can be determined that the higher the apparent resistance value, the smaller the inner diameter of the external insulating wall 12.

In the above theoretical analysis, the electrical measurement sensor 1010 is analyzed as a model when surrounded by the external insulating wall 12. However, instead of the external insulating wall 12, even if it is a conductive wall, if the electrical conductivity is lower than the electrical conductivity of the solution 11, the apparent resistance values Rm 1, Rm 2, and Rm 3 are relative to each other. FIG. 8 and FIG. 9 have the same relationship.

Since the apparent resistance value corresponds to the diameter of the external insulating wall 12, when two or more voltage detection electrode sets are provided, the diameter of the external insulating wall at the position of the voltage detection electrode group having the larger apparent resistance value. Can be determined to be smaller than the diameter of the external insulating wall at the position of the voltage detection electrode set having the smaller apparent resistance value. Therefore, by moving the electrical measurement sensor 1010 provided with a plurality of voltage detection electrode sets and comparing the measured apparent resistance values, a portion where the outer insulating wall is constricted (that is, the inner radius of the outer insulating wall). Can be easily found. Further, the value of the diameter of the insulating pipe or the like can be determined from the resistance value by the formula (14a), the formula (14b), and the formula (14c).

Furthermore, in the quantitative analysis described above, a model using the external insulating wall 12 as an external pipe has been studied, but it may not be electrically insulative. That is, if the electric conductivity of the solution 11 is somewhat lower than that of the solution 11 and the electric conductivity has several times the contrast, it is possible to find a site where the constriction has advanced. For example, taking blood vessels as an example, the electrical conductivity of blood is about 0.6 S / m, and thrombus and plaque are about 0.1 to 0.07 S / m. Therefore, a site where the blood vessel is narrowed by a thrombus or plaque can be found using the electric measurement sensor 1010.

Furthermore, when a stent is attached to the inner wall of the blood vessel, when the stent is metallic, the apparent resistance value of the portion decreases. Therefore, it is possible to find the position where the place having the lowest apparent resistance value locally is the site where the stent is mounted.

In any case, the position specified as the stenosis or the stent attachment site can be specified with respect to the insertion distance at which the electrical measurement sensor 1010 is inserted into the pipe or blood vessel from the outside.

According to the above-described embodiment, in an insulating pipe filled with a solution, a pipe having some conductivity, and a blood vessel, a site where stenosis has advanced due to thrombus, plaque, etc. can be easily performed without angiographic examination. Can be found. Therefore, the burden on the patient due to the angiographic examination is eliminated. Moreover, according to the above embodiment, it is possible to detect a stent and determine a staying site where a stent is attached with an enlarged radius in a blood vessel.

[Embodiment of electrical measurement sensor]
1 includes two or more voltage detection electrodes 1014, 1015, 1015, and 1016 (in this case, two sets) in an intermediate portion where one set of current electrodes 1012 and 1013 is arranged. (Hereinafter referred to as “electric caliper”). By comparing these two or more sets of voltage detection electrodes 1014, 1015 and 1015, 1016, the potential difference (or the apparent resistance value obtained by dividing the potential difference by the current value supplied via the current electrodes 1012 and 1013) is large. The position of the stenosis site can be specified by utilizing the fact that the set of corresponding voltage detection electrodes is at a position where the inner diameter of the external insulating wall is small. In the following, a specific embodiment of an electric caliper that can be used as the electric measurement sensor 1010 in the inner diameter measuring apparatus shown in FIG. 1 will be described using the reference numerals corresponding to the reference numerals shown in FIG.

FIG. 10 is a diagram illustrating a configuration example of the electric caliper 201 used as the electric measurement sensor 1010 in the inner diameter measuring apparatus shown in FIG. In the following, considering the similarities in structure, the reference numerals used in the electrical conductivity sensor 100 shown in FIG.

The electric caliper 201 shown in FIG. 10 includes an insulating casing 1 (corresponding to the insulating casing 1011 in FIG. 1) having at least a surface made of an insulating material and having a substantially cylindrical shape. Two current electrodes 5 and 6 (corresponding to the current electrodes 1012 and 1013 in FIG. 1) are formed at positions on the surface of the insulating housing 1 that are separated from each other in the cylindrical axial direction. Between the two current electrodes 5 and 6 on the surface of the insulating housing 1, three or more (four in this example) voltage detection electrodes 71, 81, 72, and 82 ( voltage detection electrodes 1014, 1015 in FIG. 1). 1016). In the electric caliper 201, a current is supplied from the outside between the current electrodes 5 and 6, and a conductive cable for taking out the voltage generated between the voltage detection electrodes 71 and 81 and between the voltage detection electrodes 72 and 82 to the outside (see FIG. The conductive cable is enclosed in the external lead-out cable sheath 4 (corresponding to the external lead-out cable sheath 1018 in FIG. 1). Each electrode of the electric caliper 201 and the surface of the insulating housing 1 form substantially the same cylindrical surface. This is to prevent edge effects at the edges of the electrodes.

The external lead-out cable sheath 4 in which the conductive cable is encapsulated is not formed by a member independent of the insulating casing 1 but can be formed by extending the insulating casing 1. By making the insulating housing 1 and the outer lead-out cable sheath 4 as an integral member, the electric caliper 201 can be used as a form of a catheter (ie, an electric caliper catheter) for the purpose of finding a stenosis in a blood vessel. This is particularly effective when This is because, since the external lead-out cable sheath 4 is not an independent member, the shielding effect of the insulating housing 1 becomes good, and bacterial infection in the blood vessel can be drastically reduced.

The insulating housing 1 includes a conductive cable or individual conductive wires of the conductive cable. Further, a filler made of an insulating material different from that of the insulating housing 1 is sealed in the insulating housing 1. By stopping, the bending of the insulating housing 1 can be increased. In particular, when an electric caliper catheter is constituted by the electric caliper 201, this has a remarkable effect that the risk of damage to the inner wall of the blood vessel is reduced and the electric caliper catheter can be operated safely.

FIG. 11 shows an electric caliper 202 having a configuration different from that of the electric caliper 201 shown in FIG.

In the electric caliper 201 shown in FIG. 10, at least a part, preferably all, of the current electrodes 5 and 6 and the voltage detection electrodes 71, 81, 72, and 82 are formed by independent metal electrode members. The individual conductive wires of the conductive cable enclosed in the external lead-out cable sheath 4 are connected to each other.

On the other hand, in the electric caliper 202 shown in FIG. 11, the voltage detection electrodes 71, 81, 72, and 82 are not members independent of the conductive cable, and the end surfaces of the conductive wires constituting the conductive cable are the surface of the insulating housing 1. It is exposed and formed. Although independent metal electrode members are used for the current electrodes 5 and 6, the current electrodes 5 and 6 can have the same configuration depending on the conditions of the current flowing around the electric caliper 202.

FIG. 12 is a diagram for explaining the configuration of an electric caliper 203 which is a modification of the electric caliper 202 shown in FIG. The electric caliper 203 is provided with three sets of voltage detection electrodes 71a, 81a, 72a, and 82a that are 120 degrees apart from each other on the rotation plane about the longitudinal axis of the insulating casing 1. For this reason, the presence / absence of the stenosis can be examined in the examination target space in three directions within the plane of rotation. These electrodes are formed such that the end surfaces of the conductive wires constituting the conductive cable are exposed on the surface of the insulating housing 1.

Here, the case where the number of voltage detection electrodes is four has been described, but this number may be any number as long as it is three or more. The structure in that case is essentially equivalent to any of the structures shown in FIGS. In this case, only the number of detection electrodes and the number of conductive cables connected to the detection electrodes or conductive cables whose end faces serve as voltage detection electrodes are increased. The details are omitted.

FIGS. 13 and 14 are diagrams for explaining a connection form between each electrode of the electric calipers 201 to 203 shown in FIGS. 10 to 12 and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG. The reference number of the electric caliper 203 is shown in parentheses. In the electric caliper 2003, the voltage measuring device 32 and the group of voltage detection electrodes 71a, 81a, 72a, 82a and the like shown in FIGS. 10 to 12 are provided in three sets corresponding to the respective inspection target spaces in the three directions. Yes.

In the electrical connection shown in FIG. 13, the current electrodes 5 and 6 are connected to the current power supply 31 provided in the current supply source 1021 built in the electrical measuring unit 1020 shown in FIG. . A voltage measuring device 32 provided in the voltage detecting unit 1022 in the electric measuring unit 1020 is connected to each of the voltage detecting electrodes 71 and 81 (71a and 81a) and 72 and 82 (72a and 82a). Note that the physical positions and sizes of the electrical measurement unit 1020, the current supply source 1021, and the voltage detection unit 1022 are conceptually displayed in order to clarify the electrical connection form. The voltage measuring device 32 is provided for each electrode set composed of two adjacent electrodes among the voltage detection electrodes 71, 81, 72, 82 (71a, 81a, 72a, 82a), that is, the voltage detection electrodes 71, 81 (71a). , 81a) and the electrode set consisting of the voltage detection electrodes 72, 82 (72a, 82a) are measured for voltage. With the two sets of voltage detection electrodes, a potential difference (and therefore a resistance value) corresponding to the internal diameter of a blood vessel or the like can be obtained.

FIG. 14 shows the connection configuration between each electrode and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG. 1 for the electric caliper 204 having three voltage detection electrodes and different from those shown in FIGS. It is a figure explaining. Regarding the electric caliper shown in FIG. 14 and the subsequent drawings, the same parts and structures as those shown in FIGS. 10 to 12 can be determined by deduction from the above description, and thus detailed description thereof is omitted. To do.

In the example shown in FIG. 13, the voltage is measured for each electrode set including two electrodes adjacent to each other. On the other hand, in the example of FIG. 14, among the voltage detection electrodes 701, 702, and 703, two electrode pairs adjacent to each other share one electrode, that is, a set of voltage detection electrodes 701 and 702. The voltage is measured by the voltage measuring device 32 for each set of the voltage detection electrodes 702 and 703. By using the voltage detection electrode 702 as a common electrode, the number of electrodes can be reduced. This is because the resistance value corresponding to the diameter of the blood vessel or the like may be a potential difference appearing at the two voltage detection electrodes, so that the object can be achieved without using two independent voltage detection electrodes.

FIG. 15 is a diagram for explaining a connection form between each electrode and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG. 1 for the electric caliper 205 having a different number of voltage detection electrodes from those shown in FIGS. 10 to 13. is there.

The electric caliper 205 has three sets of voltage detection electrodes 71 and 81, 72 and 82, 73 and 83 as voltage detection electrodes. With these electrode sets, resistance values corresponding to the diameters of blood vessels and the like at three different positions are measured. Thereby, as will be described later, it becomes easy to determine the site of the stenosis.

FIG. 16 is a diagram for explaining a connection form between each electrode and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG. 1 for the electric caliper 206 having a different number of voltage detection electrodes.

The electric caliper 206 has voltage detection electrodes 701 to 704, and among these, two voltage detection electrodes 702 and 703 are used as shared electrodes. As a result, the same measurement as when three sets of voltage detection electrodes are provided is possible while reducing the number of electrodes. This is based on the same concept as the example shown in FIG.

FIG. 17 is a diagram for explaining a connection form between each electrode and the electric measurement unit 1020 in the inner diameter inspection apparatus shown in FIG. 1 for the electric caliper 207 having a different number of voltage detection electrodes.

The electric caliper 207 has voltage detection electrodes 701 to 705, of which three voltage detection electrodes 702 to 704 are used as common electrodes, respectively. This makes it possible to perform the same measurement as when four sets of voltage detection electrodes are provided while reducing the number of electrodes.

FIG. 18 and FIG. 19 are diagrams for explaining an electric caliper 208 having a different configuration from that described above (for example, the electric caliper shown in FIG. 10). FIG. 18 shows the structure of the electric caliper 208, and FIG. 19 shows the spatial distribution of current generated by the electric caliper 208.

The electric caliper 208 includes two current electrodes 50 and 60 as current electrodes, one of which is the side opposite to the side where the conductive cable of the insulating housing 1 and the external lead-out cable sheath 4 are attached. The insulating casing 1 is formed at the front end portion. By disposing the current electrode 50 in this way, as shown in FIG. 19, the current from the current electrode 50 is diffused and released in almost all directions, so that the current distribution is the surface of the insulating casing 1 at the voltage detection electrode. It becomes difficult to localize. That is, the current spatial distribution does not depend much on the radial direction of the insulating casing 1, and the radial direction dependence coefficient n is close to zero. Therefore, as can be seen from the equation (14b) and FIG. 9, the influence of the resistance value on the change of the constriction portion is strong. Therefore, it becomes easy to detect the constriction.

In the above description, the maximum number of voltage detection electrode groups of the electric caliper is four, but the number of voltage detection electrode groups may be five or more. In addition, regarding the configuration in which one of the current electrodes (current electrode 50) is disposed at the distal end portion of the insulating housing 1, the arrangement of the voltage detection electrodes may be different from that shown in FIGS.

20 and 21 are diagrams for explaining an electric caliper 209 having a different configuration from the electric caliper shown in FIGS. 10 to 19 described above. FIG. 20 shows a structure of the electric caliper 209, and FIG. 21 is a diagram for explaining a connection form between each electrode and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG.

In the electric caliper 209, two electrode groups including two current electrodes and three or more voltage detection electrodes are formed in the axial direction of the insulating housing 1. That is, the electric caliper 209 has two current electrode sets 51, 61, 52, 62, and the voltage detection electrodes 71, 81, 72, 82 and 73, 83, 74, 84 are provided between the sets. Is arranged. The current electrodes 51, 61 and 52, 62 are connected to different current power sources 31 provided in the current supply source 1021 in the electric measuring unit 1020. A voltage measuring device 32 provided in the voltage detecting unit 1022 in the electric measuring unit 1020 is connected to the voltage detecting electrodes 71 and 81, 72 and 82, 73 and 83, 74 and 84, respectively.

In the example shown up to FIG. 19, there is one set of current electrodes. In this case, if an extremely narrowed portion is located between the current electrodes, the entire current flowing in the solution 11 is reduced by the narrowed portion, and the voltage of the potential difference detected by the voltage detection electrode is reduced. In particular, since the potential difference at a portion other than the constricted portion is small, the voltage is small, and measurement may be difficult. On the other hand, in the electric caliper 209 shown in FIGS. 20 and 21, the external constriction can be detected independently by the current electrodes 51 and 61 and the current electrodes 52 and 62. As a result, the voltage detection electrode arranged between one set of current electrodes is in the vicinity of the constriction, so that the potential difference between the voltage detection electrodes detected there, particularly at a position outside the constriction, is reduced. Since the potential difference detected by the voltage detection electrode arranged between the other sets of current electrodes does not become small, the voltage other than the constriction can be normally measured by the latter set of current electrodes.

22 and 23 are diagrams showing an electric caliper 210 that is a modification of the electric caliper 209 shown in FIGS. 20 and 21. FIG. FIG. 22 shows the structure of the electric caliper 209, and FIG. 23 is a diagram for explaining the connection form between each electrode and the electric measuring unit 1020 in the inner diameter inspection apparatus shown in FIG.

In addition to the two current electrodes 5, 6, the electric caliper 210 is between the two current electrodes 5, 6 and is paired with each of the two current electrodes 5, 6. A third current electrode 56 is formed at a position sandwiching 72 and 82. That is, two sets of voltage detection electrodes 71, 81 and 72, 82 are arranged between the pair of current electrodes 5, 6, and are common between the two sets of voltage detection electrodes 71, 81 and 72, 82. A current electrode 56 is provided. Since the current flowing between one set of current electrodes 5 and 56 is independent of the current flowing between the other set of current electrodes 6 and 56, the constricted portion is located in one set of voltage detection electrodes. Even so, the voltage of the other set of voltage detection electrodes is generated by the current flowing between the different sets of current electrodes, so it does not become small and can therefore be measured normally.

[Configuration of electrical measurement unit]
As the current power source 31 used for the current supply source 1012 in the electric measuring unit 1020 and the voltage measuring device 32 used for the voltage detection unit 1022, either a DC circuit or an AC circuit can be used. On the other hand, when a direct current is passed from the current electrode to the solution 11 or blood, these energized media may be electrolyzed. In this case, an AC circuit is used. Such a configuration will be described below.

FIG. 24 shows a configuration example of the current power supply circuit 310 used as the current power supply 31.

The current power supply circuit 310 is an AC power supply circuit, and the output of the AC signal generator 311 is input to the first voltage converter 312, and the AC current that appears on the secondary side of the voltage converter 312 is the current electrode 5, 6. Has been supplied to. In order to monitor the AC current on the secondary side, the AC current is input to the current-voltage conversion circuit including the operational amplifier 315 and the resistor 316 via the second voltage converter 313. The output of the current-voltage conversion circuit is input to a detector 317 (its detailed circuit is the same in configuration as the detector 325 shown in FIG. 25), and the current supplied to the current electrodes 5 and 6 is converted into a voltage. Further, it is detected as a DC voltage by the detector 317.

FIG. 25 shows a configuration example of a voltage measuring circuit 320 used as the voltage measuring device 32.

The voltage measuring circuit 320 converts the voltage of the potential difference that appears on the voltage detection electrode into an AC voltage that appears on the secondary side via a voltage converter 321 as a transformer that performs electrical insulation and voltage conversion. The voltage is input to a voltage conversion circuit including an operational amplifier 323 and a resistor 324 through a resistor 322. The output of this voltage conversion circuit is input to the detector 325. In the detector 325, the output of the voltage conversion circuit is input to the synchronous detector 327 that is synchronously controlled by the synchronous signal generator 326, and the output is output as a DC voltage output V 1 or V 2 or the like via the filter 328. .

FIG. 26 shows a configuration example of another voltage measuring device circuit 330 used as the voltage measuring device 32. This voltage measuring device circuit 330 is used for voltage measurement of the electric calipers 204, 206, and 207 that detect a voltage for each electrode set that shares a part of the voltage detection electrode. Here, the electric caliper 206 shown in FIG. 16 will be described as an example.

The voltage detection electrodes 701, 702, 703, and 704 of the electric caliper 206 are connected to voltage converters 337 to 339 via capacitors 331 to 336, respectively. More specifically, the voltage detection electrode 701 is connected to the voltage converter 337 via the capacitor 331. The voltage detection electrode 702 that is a common electrode is branched and connected to the voltage converter 337 via the capacitor 332 and to the voltage converter 338 via the capacitor 333. A voltage detection electrode 703 which is also a common electrode is branched and connected to the voltage converter 338 via the capacitor 334 and to the voltage converter 339 via the capacitor 335. The voltage detection electrode 704 is connected to the voltage converter 339 via the capacitor 336. The DC path is blocked by passing through the capacitors 331 to 336. The output of the voltage converter 337 is input to a voltage amplifier circuit composed of an operational amplifier 343 and resistors 340 and 344. The output of the voltage converter 338 is input to a voltage amplifier circuit including an operational amplifier 345 and resistors 341 and 346. The output of the voltage converter 339 is input to a voltage amplification circuit including an operational amplifier 347 and resistors 342 and 348. The outputs of these voltage amplification circuits are detected by detectors 349 to 351, and become voltage outputs V1, V2, and V3. A configuration example of a circuit used as the detectors 349 to 351 is shown in FIG.

27 includes a rectifier circuit 420 and a low-pass circuit 421. The rectifier circuit 420 includes an operational amplifier 418, a diode 417, resistors 410 and 411, and a capacitor 414. The operational amplifier 418 outputs only the negative voltage portion of the AC signal from the diode 417. The amplification degree is determined by the ratio of the resistors 411 and 410. The capacitor 414 suppresses the negative voltage pulsating component. The low-pass circuit 421 is a secondary Butterworth circuit including an operational amplifier 419, resistors 412 and 413, and capacitors 415 and 416. The signal having the pulsating current component that is the output of the rectifier circuit 420 is effectively allowed to pass a direct current component. With the circuit shown in FIG. 27, after the AC voltage detected by the voltage detection electrodes 701, 702, 703, and 704 is passed through the voltage amplification circuit, a DC voltage proportional to the magnitude of the AC voltage can be obtained.

In the configuration of the voltage measuring circuit 330 shown in FIG. 26, if the capacitors 331 to 336 are not provided, the impedance of the primary windings of the voltage transformers 337 to 339 increases, and low-frequency noise such as heartbeat is The voltage is input to the current-voltage conversion circuit and the subsequent detectors 349 to 351 through the transformers 337 to 339. As a result, this low frequency noise other than the signal of the current supply source is mixed in the output after detection. By inserting capacitors 331 to 336 on the primary side and increasing the input impedance of the voltage converters 337 to 339, such low frequency noise can be cut off.

Here, the case where the voltage is measured by the voltage detection electrodes 701, 702, 703, and 704 of the electric caliper 206 has been described as an example. However, by increasing or decreasing the number of detection circuits composed of operational amplification and resistors and detectors, It can be applied to the configuration of the voltage detection electrode of the electric caliper and the configuration of many more voltage detection electrodes.

[Usage form]
Next, as a utilization form of the present invention, a measurement system used for finding a stenosis, its display method, and a method for finding a stenosis will be described. An electrical measurement sensor (particularly referred to as “electric caliper balloon catheter”) capable of attaching a stent to a vascular stenosis will also be described.

</ RTI> By using the inner diameter inspection apparatus of the present invention, at least two voltages or apparent resistance values are compared to determine the site of stenosis. The determination is quick and simple to make visually. Next, a specific method will be described.

As the electric measurement sensor 1010 described with reference to FIG. 1, one of the electric calipers 201 to 210 or an electric caliper equivalent thereto is used. The current value supplied to the current electrode of the electric caliper is output as the current value A (which may be two of A1 and A2) of the digital signal via the analog / digital converter 1023. The signal of each voltage detection electrode of the electric caliper is connected to the voltage detection unit 1022 in the electric measurement unit 1020 via an external lead cable 1019 connected to each electrode. The signal is output as voltage values V1, V2,..., Vm of the digital signal via the analog / digital converter 1023. The arithmetic processing unit 1024 calculates apparent resistance values R1 to Rm by dividing these signals by the corresponding current. Thereafter, the image generation processing unit 1025 detects the apparent resistance values R1, R2,..., Rm in the order of the voltage detection electrodes arranged in the electric caliper, and detects the voltages corresponding to the resistance values R1, R2,. A resistance comparison image in which the positions of the electrodes are arranged in the horizontal axis direction is displayed on the display device 1030 as a diagram.

[Stenosis determination method]
In order to find a stenosis part such as a blood vessel, the image generation processing part 1025 compares the magnitude relationship between two or more apparent resistance values R1, R2,..., Rm in correspondence with the positions of three or more voltage detection electrodes. A resistance comparison image that can be generated is generated, and the embolized portion generated in the space area to be inspected is indicated by the resistance comparison image.

[Judgment based on two apparent resistance values]
A method for determining a stenosis based on two apparent resistance values will be described. At this time, the image generation processing unit 1025 processes the two apparent resistance values calculated by the calculation processing unit 1024. Of the three or more voltage detection electrodes, the two electrode sets that give two apparent resistance values move the electric measurement sensor in the direction of the electrode set that gives a relatively large resistance value among the two apparent resistance values. When the two apparent resistance values become equal after the apparent resistance value of the electrode set becomes the maximum value, it is assumed that a constriction exists at the midpoint of the two electrode sets, and the resistance value comparison Generate an image. This resistance value comparison image is displayed on the display device 1030.

The operator who operates the electric caliper
1) Compare the relative magnitudes of two apparent resistance values in the diagram (resistance value comparison image) displayed on the display device 1030.
2) Move the electric caliper in the direction of the voltage detection electrode corresponding to the higher one of these apparent resistance values.
3) Thereafter, the electric caliper is further moved in the same direction, and it is confirmed that the apparent resistance value shows the maximum value and then decreases and the other apparent resistance value increases.
4) Then, gradually move the electric caliper in the same direction, and confirm that the apparent resistance value and the other apparent resistance value are equal.
5) At this position, it is determined that a constriction exists at the midpoint between the two voltage detection electrodes of the electric caliper.

In this method, the norm of the principle operation is based on comparing the resistance values adjacent to each other so that the portion between the voltage detection electrodes having a larger resistance value is a portion where a stenosis occurs in the pipe or blood vessel.

FIG. 28 shows an example of a resistance value comparison image using two apparent resistance values R1 and R2. In the electric calipers 201, 202, and 204 that can measure two voltages, as shown in FIG. 28, the apparent resistance values R1 and R2 are displayed on the display device 1030 by a straight line connecting the two apparent resistance values R1 and R2. When displayed, it is possible to easily determine between the voltage detection electrodes close to constriction by the inclination of the straight line. When the apparent resistance values of R1 and R2 are equal, that is, when the slope of the straight line becomes zero, it can be determined that the constriction is located between the two voltage detection electrodes. At this time, it is also possible to assist the operator's judgment based on a sound, a change in color of the screen, or the like.

[Judgment based on three apparent resistance values]
A method for determining a stenosis based on three apparent resistance values will be described. At this time, the image generation processing unit 1025 processes the three apparent resistance values calculated by the arithmetic processing unit 1024, and for three electrode sets that give three apparent resistance values among the three or more voltage detection electrodes, After the electric capacity moves in the direction of the electrode set that gives a relatively large resistance value among the three apparent resistance values, and the apparent resistance value of the electrode set reaches the maximum value, the center of the three electrode sets When the apparent resistance value required for the electrode group is maximized, a resistance value comparison image is generated assuming that a constriction exists at the midpoint of the center electrode group.

The operator who operates the electric caliper
1) In the diagram (resistance value comparison image) displayed on the display device 1030, the relative magnitudes of the three apparent resistance values are compared.
2) The electric caliper is moved in the direction of the voltage detection electrode corresponding to the larger one of these apparent resistance values.
3) After that, when the electric caliper is further moved in the same direction, and the apparent resistance value having the larger resistance value shows the maximum value, three sets of voltages of the electric caliper at the position corresponding to the middle voltage detection electrode It is determined that a constriction exists at the midpoint of the voltage detection electrode in the middle of the detection electrode.

Even in this determination method, the principle of the principle operation is that the portion between the voltage detection electrodes having the largest resistance value is a portion where a stenosis is caused in the blood vessel or pipe by comparing adjacent resistance values. by.

FIG. 29 shows an example of a resistance value comparison image using three apparent resistance values R1, R2, and R3. For example, the three apparent resistance values R1, R2 and R3 can be obtained by using the electric calipers 205 and 206 capable of measuring three voltages. The image generation processing unit 1025 generates the three apparent resistance values R1, R2, and R3 as a resistance comparison image together with the connecting straight lines, and displays the resistance comparison image on the display device 1030. Thereby, as shown in FIG. 29, the difference between the resistance values R1, R2, and R3 is displayed as two straight lines.

The upper diagram of FIG. 29 shows that the gap between the electrodes corresponding to the apparent resistance value R3 is close to the constricted portion, and the middle diagram is the electrode between the electrodes corresponding to the apparent resistance value R2 and the electrode corresponding to the apparent resistance value R3. It can be seen that there is a stenosis between them. In the figure below, the apparent resistance value R2 indicates the maximum value of the apparent resistance value, and it can be determined that the portion is most narrowed. In particular, when three apparent resistance values R1, R2, and R3 are used, the portion where the apparent resistance value R2 positioned therein is the maximum compared to the other apparent resistance values R1 and R3 is the constriction. Can be judged. For this reason, this determination method is a user-friendly visualization method that facilitates determination of a stenosis.

The above judgment method is to judge and determine the stenosis part by comparing adjacent apparent resistance values, and between the voltage detection electrodes having the larger resistance value causes stenosis in the blood vessel or the water pipe or the sewer pipe. This is based on the fact that it is a part.

[Identification of stent position]
By utilizing the inner diameter inspection apparatus of the present invention, it is possible to find the site of the stent attached to the inner wall of the blood vessel and specify its position. The method of determination and determination of the stent mounting part is based on the principle of operation of the principle, by comparing adjacent resistance values, the portion between the voltage detection electrodes having the smaller resistance values is the site where the stent is mounted in the blood vessel. It is in line with that. Therefore, in the method for determining and determining the stenosis, the place where the resistance value is large is used as an indicator for determination. However, in the case where the stent is attached and determined, the place where the resistance value is small is used as an indicator for determination. .

In this case, two or more voltage values detected by the voltage detection electrode change according to the influence of the conductivity of the inspection target space, and the image generation processing unit 1025 shows the magnitude relationship between the two or more apparent resistance values. A resistance value comparison image that can be compared in correspondence with the position of three or more voltage detection electrodes is generated, and a portion (specifically, the position of the stent) in which the conductivity is different from other portions in the inspection target space This is shown in the display device 1030.
[Judgment based on two apparent resistance values]
A method of determining a stent site based on two apparent resistance values will be described. At this time, the image generation processing unit 1025 processes the two apparent resistance values calculated by the arithmetic processing unit 1024, and for two electrode sets that give two apparent resistance values among three or more voltage detection electrodes, The two apparent resistance values after the electrical measurement sensor moves in the direction of the electrode set that gives a relatively small resistance value out of the two apparent resistance values, and the apparent resistance value of the electrode set becomes the minimum value. When the two values become equal, a resistance comparison image is generated assuming that a stent exists at the midpoint between the two electrode sets. This resistance value comparison image is displayed on the display device 1030.

FIG. 30 shows an example of a resistance value comparison image based on two apparent resistance values R1 and R2. In the electric calipers 201, 202, and 204 that can measure two voltages, as shown in FIG. 30, the apparent resistance values R1 and R2 are displayed on the display device 1030 by a straight line connecting the two apparent resistance values R1 and R2. When displayed, it is possible to easily determine between the voltage detection electrodes near the portions having different conductivities by the inclination of the straight line. When the apparent resistance values of R1 and R2 are equal, that is, when the slope of the straight line becomes zero, it can be determined that the site where the stent is mounted is located between the two voltage detection electrodes. At this time, it is also possible to assist the operator's judgment based on a sound, a color change of the screen, or the like.

The operator who operates the electric caliper
1) Compare the relative magnitudes of two apparent resistance values in the diagram (resistance value comparison image) displayed on the display device 1030.
2) Move the electric caliper in the direction of the voltage detection electrode corresponding to the smaller of these apparent resistance values,
3) Thereafter, the electric caliper is further moved in the same direction, and it is confirmed that the apparent resistance value shows the minimum value, then increases and then the other apparent resistance value decreases.
4) After that, gradually move the electric caliper in the same direction, and confirm that the apparent resistance value and the other apparent resistance value are equal.
5) At this position, it is determined that a stent is present at the midpoint between the two voltage detection electrodes of the electric caliper.

[Judgment based on three apparent resistance values]
A method for determining the site of the stent based on the three apparent resistance values will be described. At this time, the image generation processing unit 1025 processes the three apparent resistance values calculated by the arithmetic processing unit 1024, and for three electrode sets that give three apparent resistance values among the three or more voltage detection electrodes, After the electric caliper moves in the direction of the electrode set that gives a relatively small resistance value among the three apparent resistance values, and the apparent resistance value of the electrode set becomes the minimum value, the center of the three electrode sets When the apparent resistance value required for the electrode group is minimized, a resistance value comparison image is generated assuming that the stent is mounted at the midpoint of the center electrode group.

FIG. 31 shows an example of a resistance value comparison image using three apparent resistance values R1, R2, and R3.
For example, the three apparent resistance values R1, R2 and R3 can be obtained by using the electric calipers 205 and 206 capable of measuring three voltages. The image generation processing unit 1025 generates the three apparent resistance values R1, R2, and R3 as a resistance comparison image together with the connecting straight lines, and displays the resistance comparison image on the display device 1030. Thereby, as shown in FIG. 31, the difference of resistance value R1, R2, R3 is displayed as two straight lines.

The upper diagram in FIG. 31 shows that the distance between the electrodes corresponding to the apparent resistance value R3 is close to the site where the stent is mounted. In the middle diagram, the distance between the electrodes corresponding to the apparent resistance value R2 and the apparent resistance value R3 are shown. It can be seen that there is a site where a stent is mounted between corresponding electrodes. And in the following figure, although the apparent resistance value R2 shows the minimum value of the apparent resistance value, it can be determined that the portion is in the middle of the site where the stent is mounted.

In this case, the operator who operates the electric caliper
1) In the diagram (resistance value comparison image) displayed on the display device 1030, the relative magnitudes of the three apparent resistance values are compared.
2) Move the electric caliper in the direction of the voltage detection electrode corresponding to the smaller of these apparent resistance values,
3) After that, when the electric caliper is further moved in the same direction, and the apparent resistance value having the smaller resistance value indicates the minimum, three sets of voltage detection of the electric caliper are performed at the position corresponding to the middle voltage detection electrode. It is determined that there is a site where a stent is attached to the voltage detection electrode located in the middle of the electrode.

In the above determination method as well, the principle of the principle operation is that the adjacent resistance value is compared, and the portion between the voltage detection electrodes having the smaller resistance value is the site where the stent is mounted in the blood vessel. In particular, when three apparent resistance values R1, R2, and R3 are used, the portion where the apparent resistance value R2 positioned therein is minimum compared to the other apparent resistance values R1 and R3 is the site where the stent is mounted. Can be determined. For this reason, this determination method is a user-friendly visualization method in which it is easy to determine the site where the stent is attached.

FIG. 32 is a diagram illustrating a configuration example of the electric caliper balloon catheter 211 used as the electric measurement sensor 1010 in the inner diameter measuring apparatus shown in FIG. As described above, the electric caliper according to the present invention has the ability to detect and determine the location of thrombus or plaque in the blood vessel, so that the stent is correctly attached to the site of the blood vessel constriction due to the thrombus or plaque. It can be applied to a balloon catheter that can be used. FIG. 32 shows such an example.

The electric caliper balloon catheter 211 shown in FIG. 32 is inflated or deflated by a gas or liquid supplied via a pipe (not shown) to the distal end portion of the insulating casing 1 of the electric caliper 201 shown in FIG. Is provided. A stent 95 that is expanded beyond the elastic limit by inflating the balloon 90 is attached to the balloon 90. A pipe for supplying a gas or liquid to the balloon 90 is extended inside the insulating housing 1 via the external lead-out cable sheath 4.

More specifically, the insulating casing 1 is provided with a pair of current electrodes 5 and 6, and two sets of voltage detection electrodes 71, 81 and 72, 82 are provided therebetween. A balloon 90 is provided in a portion from the current electrode 5 to one end portion of the insulating housing 1. When the electric caliper balloon catheter 211 is used, a stent 95 to be mounted in the blood vessel is inserted on the surface of the balloon 90. An external lead-out cable 1019 (see FIG. 1) connected to the electrical measurement unit 1020 (see FIG. 1) is sealed in the external lead-out cable sheath 4 from the other end of the insulating housing 1. A pipe for supplying and supplying a gas or liquid for the balloon is enclosed in the outer lead-out cable sheath 4 and also in the insulating housing 1. The pipe may be enclosed in a sheath different from the external lead-out cable. Each electrode and the surface of the insulating housing 1 form substantially the same cylindrical surface. This is to prevent an edge effect at the edge of the electrode. Further, in order to smoothly introduce the electric caliper balloon catheter 211 into the blood vessel, the balloon 90 forms a cylindrical surface that is substantially the same as the surface of the insulating housing 1 when contracted.

32. To use the electric caliper balloon catheter 211 shown in FIG. 32, first, a stenosis site is specified by the method described above. Then, the electric caliper balloon catheter 211 at that location is pulled out of the blood vessel region by a distance determined by the midpoint between the voltage detection electrodes 81 and 72 and the midpoint in the longitudinal direction of the stent 95. Next, the balloon 90 is inflated by pressurizing and injecting balloon inflation gas or liquid, and the stent 95 is expanded at the narrowed portion. Thereafter, the balloon gas or liquid is discharged under reduced pressure to reduce the balloon 90, and the expanded stent 95 is placed in the stenosis. After the stent 95 is stopped, the electric caliper balloon catheter 211 is moved again to the stent side, and the stent attachment site is determined by the method described above. It is confirmed by the introduction distance in the blood vessel of the electric caliper balloon catheter 211 that the identified stent mounting site matches the original stenosis site.

When using such an electric caliper catheter 211, since the angiographic agent is unnecessary or the minimum amount, the burden on the patient is small, and the diagrams shown in FIGS. 28 to 31 are used. Can continuously find, judge, and determine the stenosis, as well as confirm the stent attachment site. With this continuous real-time property, convenience and patient safety can be significantly improved.

FIG. 33 shows an electric caliper 212 showing an example of an electrode structure formed by windings. A similar electrode structure can be adopted even for an electric caliper catheter.

In the electric caliper or the electric caliper balloon catheter according to the present invention, when the diameter of the insulating casing 1 is reduced, it is difficult to form and electrically connect two members, the electrode and the external lead-out cable independently. In the electrode structure shown in FIG. 33, the electrode and the conductive wire constituting the external lead-out cable are integrated, and all are formed by the external lead-out cable.

That is, the insulating housing 1 has a cylindrical shape, and small openings 501, 502, 711, 712, 811, 812, 721, 722, 821, 822 are formed on the surface thereof. Using one adjacent opening, one single-wire conductive wire of a conductive wire bundle 41 configured by bundling single-wire conductive wires having a plurality of insulating coatings is drawn out from one of the openings, and the insulating housing 1 The surface is densely wound by one layer, and the surface forms an electrode. For example, the current electrode 5 is formed by drawing one single-wire conductive wire in the conductive wire bundle 41 from the opening 502 and winding it around the surface of the insulating housing 1, and inserting the end of the single-wire conductive wire into the opening 501. . Thereafter, the insulating coating on the surface of the single-wire conductive wire is completed by removing with a polishing or stripping agent.

However, in such a structure, the electrode has a shape protruding from the surface of the insulating housing 1 by the diameter of the single-wire conductive wire. As a result, the edge effect of the electrode increases, so-called surface current flowing near the surface of the insulating housing 1 increases, and the response of the voltage detected by the voltage detection electrode to the diameter of the constricted portion becomes worse. In order to solve this problem, an electric caliper or electric caliper balloon catheter having a structure in which a single conductive wire to be an electrode is embedded in an insulating housing 1 (hereinafter referred to as an embedded electrode electric caliper or an embedded electrode electric caliper balloon). Called a catheter).

34 and 35 show a method of manufacturing the embedded electrode electric caliper 213. FIG. 36 shows an electrode structure in the embedded electrode electric caliper 213.

In the manufacturing method shown in FIG. 34, the insulating housing base material 1a is made of a heat-softening resin. One single-wire conductive wire 511 forming the conductive wire bundle 41 is inserted from one end of the insulating housing 1a and taken out from the opening 502 to the outside. A portion of the insulating coating that goes out from the opening 502 of the single wire conductive wire is peeled off by a chemical method or left as it is. Thereafter, the single-wire conductive line 511 is wound further on the insulating casing 1a to a position where the other opening is blocked. Thereafter, the electrode 250 having a sharp tip is inserted into the opening 502. At this time, the electrode 250 is electrically connected to the single wire conductive line 511 by the pressing pressure. Even if the insulating coating is applied to the single-wire conductive wire 511, electrical continuity is ensured. On the other hand, the other end of the single wire conductive line 511 is held by the electric grip 251. Conductive cables 252 and 253 are connected to the electrode 250 and the electric grip 251, and a current flows through each of them. Then, the single wire conductive line 511 generates heat due to its electric resistance. At this time, when the single-wire conductive wire 511 is further pulled by the electric grip 251, the single-wire conductive wire 511 is embedded in the outer skin of the insulating housing 1 a as shown in FIG. 35 while the insulating housing 1 a is softened by heat. So buried. Thereafter, the single conductive wire 511 on the electric grip 251 side is cut, and the cut end portion is pushed into the opening 501. Thereafter, the tip end portion 1b is attached to the insulating housing base material 1a to complete the embedded electrode electric caliper 213.

Although the electric caliper has been described as an example here, an embedded electrode electric caliper balloon catheter (not shown) can be manufactured by providing a balloon outside the electric electrodes 5 and 6 of the embedded electrode electric caliper 213 facing each other. . The manufacturing method is essentially the same as that of the embedded electrode electric caliper 213.

In addition, as for the insulating housing 1a, at the initial stage of manufacture, the tip portion is formed in a cut shape in order to ensure workability, but the tip portion 1b may be formed.

In the implanted electrode electric caliper and the implanted electrode electric caliper balloon catheter manufactured as described above, the electrode is formed from the conductive wire constituting the external lead-out cable. Therefore, the process of connecting the electrode and the external lead-out cable is unnecessary, and the present invention About such an electric caliper and an electrode electric caliper balloon catheter, a thin one can be easily realized.

In addition, this invention is not limited to the above-mentioned embodiment, In the implementation stage, it can embody by modifying a component in the range which does not deviate from the summary. Various embodiments can be made by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 Insulating housing 1a Insulating housing base material 1b Tip 2 Protection pipe 2
3 Engagement section 4 External lead-out cable sheaths 5, 6, 1012 and 1013 Current electrodes 7 and 8 Voltage detection electrode 9 Opening 11 Solution 12 External insulating wall 30 Electrical measurement section 31 Current power supply 32 Voltage measuring instrument 41 Conductive wire bundles 50 and 51, 52, 56, 60, 61, 62 Current electrodes 71, 72, 73, 74, 81, 82, 83, 84, 71a, 72a, 81a, 82a, 702, 703, 704, 1014, 1015, 1016 Voltage detection electrode 90 Balloon 95 Stent 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 212 Electric caliper 211 Electric caliper balloon catheter 213 Implanted electrode Electric caliper 250 Electrode 251 Electric grip 252 253 Conductive cable 310 Current power supply circuit 311 AC signal generation 312, 313, 321 Voltage converters 316, 322, 324, 340, 341, 342, 344, 346, 348, 410, 411 Resistors 315, 323, 343, 345, 347, 418, 419 operational amplifiers 317, 325 349, 350, 351 Detector 320 Voltage measuring circuit 326 Synchronous signal generator 327 Synchronous detector 328 Filter 330 Voltage measuring circuit 331, 332, 333, 334, 335, 336, 414, 415, 416 Capacitors 337, 338, 339 Voltage converter 417 Diode 421 Low-pass circuit 501, 502, 711, 712, 811, 812, 721, 722, 821, 822 Opening 511 Single wire conductive wire 1000 Inspection object space 1010 Electrical measurement sensor 1011 Insulating housing 1017 Conductive wire 1 018 External cable sheath 1019 External cable 1020 Electrical measurement unit 1023 Analog / digital converter 1030 Display device 1022 Voltage detection unit 1023 Analog / digital converter 1024 Arithmetic processing unit 1025 Image generation processing unit

Claims (27)

1. An electrical measurement sensor inserted into a space to be inspected filled with a conductive solution;
   A current supply source for supplying a current to the electrical measurement sensor;
   Voltage detection means for detecting the voltage of the electrical measurement sensor;
   With
   The electric measurement sensor includes an insulating housing having at least a surface made of an insulating material and having a substantially cylindrical shape, and two cylindrical electrodes formed on the surface of the insulating housing at positions separated in the axial direction of the cylindrical shape. A current electrode; three or more voltage detection electrodes formed between the two current electrodes on the surface of the insulating casing; and the inspection connected to the two current electrodes and the three or more voltage detection electrodes. A conductive cable led out of the target space, and a sheath enclosing the conductive cable;
   The current supply source is connected between the two current electrodes via the conductive cable,
   The voltage detection means is connected via the conductive cable so as to detect two or more voltages generated according to the influence of the inner diameter of the inspection target space and occurring between the three or more voltage detection electrodes. The inner diameter inspection apparatus is connected to the three or more voltage detection electrodes.
2. The inner diameter inspection apparatus according to claim 1,
   The internal diameter inspection apparatus, wherein the voltage detection unit includes a voltage measuring device that measures a voltage for each electrode set including two adjacent electrodes among the voltage detection electrodes.
3. The inner diameter inspection apparatus according to claim 1,
   The voltage detecting means includes a voltage measuring device that measures a voltage of an electrode set in which one electrode is shared for every two adjacent electrodes among the voltage detecting electrodes.
4. The inner diameter inspection apparatus according to claim 1,
   The current supply source is an alternating current source;
   The voltage detecting means includes a transformer that receives the two or more voltages and performs electrical insulation and voltage conversion, a voltage amplifier that amplifies the output voltage of the transformer, and a detector that detects the output of the voltage amplifier; An inner diameter inspection apparatus characterized by comprising:
5. The inner diameter inspection apparatus according to claim 1,
   An inner diameter inspection apparatus, wherein a capacitor for blocking low-frequency noise is inserted between a voltage detection electrode to be a voltage detection target and the transformer.
6. The inner diameter inspection apparatus according to claim 1,
   Current measuring means for measuring a current supplied from the current supply source to the current electrode;
   A computing means for computing two or more apparent resistance values corresponding to the two or more voltage values from two or more voltage values obtained by the voltage detecting means and a current value obtained by the current measuring means;
   Image generating means for generating an image in which the two or more apparent resistance values are arranged;
   An inner diameter inspection apparatus further comprising:
7. The inner diameter inspection apparatus according to claim 6,
   The image generation means generates a resistance comparison image that can compare the magnitude relationship between the two or more apparent resistance values in correspondence with the positions of the three or more voltage detection electrodes, and is generated in the inspection target space region. An inner diameter inspection device characterized by showing the embolus portion by the resistance comparison image.
8. The inner diameter inspection device according to claim 7,
   The image generating means includes
   Processing two apparent resistance values computed by the computing means;
   Among the three or more voltage detection electrodes, for the two electrode sets that give the two apparent resistance values, the electric measurement sensor in the direction of the electrode set that gives a relatively large resistance value among the two apparent resistance values Moves, and when the apparent resistance value of the electrode set becomes the maximum value and the values of the two apparent resistance values become equal, a constriction is present at the midpoint of the two electrode sets. As an inner diameter inspection device, the resistance value comparison image is generated.
9. The inner diameter inspection device according to claim 7,
   The image generating means includes
   Processing three apparent resistance values computed by the computing means;
   Among the three or more voltage detection electrodes, for the three electrode sets that give the three apparent resistance values, the electric measurement sensor in the direction of the electrode set that gives a relatively large resistance value among the three apparent resistance values When the apparent resistance value required for the central electrode set of the three electrode sets becomes the maximum after the apparent resistance value of the electrode set reaches the maximum value, the central electrode The resistance value comparison image is generated assuming that a stenosis exists at the midpoint of the set.
10. The inner diameter inspection device according to claim 7,
    The insulating housing of the electrical measurement sensor is provided with a balloon that expands or contracts by gas or liquid supplied through a pipe,
    The inner diameter inspection apparatus characterized in that the image generating means indicates a position where the balloon should be inflated or deflated by showing the embolus portion generated in the inspection target space region by the resistance value comparison image.
11. The inner diameter inspection apparatus according to claim 10,
    The balloon is attached with a stent that is expanded beyond the elastic limit by inflating the balloon,
    The image generation means indicates the embolized portion generated in the examination target space region with the resistance comparison image in a state where the electrical measurement sensor is inserted into the blood vessel, so that the blood vessel to which the stent is to be attached is displayed. Indicate position
12. The inner diameter inspection apparatus according to claim 6,
    The two or more voltage values change according to the influence of the conductivity of the inspection object space,
    The image generation means generates a resistance value comparison image that can compare the magnitude relationship of the two or more apparent resistance values in correspondence with the positions of the three or more voltage detection electrodes, An inner diameter inspection apparatus characterized in that a portion having conductivity different from that of the portion is indicated by the resistance value comparison image.
13. The inner diameter inspection device according to claim 12,
    The space to be examined is a blood vessel in which a stent is mounted,
    The image generating means includes
    Processing two apparent resistance values calculated by the calculation means;
    Among the three or more voltage detection electrodes, for the two electrode sets that give the two apparent resistance values, the electric measurement sensor in the direction of the electrode set that gives a relatively small resistance value among the two apparent resistance values Is moved, and when the apparent resistance value of the electrode set becomes the minimum value and the values of the two apparent resistance values become equal, a stent is present at the midpoint of the two electrode sets. The resistance value comparison image is generated.
14. The inner diameter inspection device according to claim 12,
    The space to be examined is a blood vessel in which a stent is mounted,
    The display processing means includes
    Processing three apparent resistance values computed by the computing means;
    Among the three or more voltage detection electrodes, for the three electrode sets that give the three apparent resistance values, the electric measurement sensor in the direction of the electrode set that gives a relatively small resistance value among the three apparent resistance values When the apparent resistance value required for the central electrode set of the three electrode sets becomes the minimum after the apparent resistance value of the electrode set reaches the minimum value, the central electrode The resistance comparison image is generated on the assumption that a stent is mounted at the midpoint of the set.
15. An insulating housing having at least a surface made of an insulating material and having a substantially cylindrical shape;
    Two current electrodes formed at positions separated from each other in the cylindrical axial direction on the surface of the insulating housing;
    Three or more voltage detection electrodes formed between the two current electrodes on the surface of the insulating housing;
    A conductive cable for supplying a current between the two current electrodes from the outside and taking out two or more voltages generated between the three or more voltage detection electrodes;
    A sheath enclosing the conductive cable;
    An electrical measurement sensor comprising:
16. In the electric measurement sensor according to claim 1 and claim 15,
    One of the two current electrodes is formed at the tip of the insulating casing opposite to the side where the conductive cable is attached to the insulating casing. Measuring sensor.
17. In the electric measurement sensor according to claim 1 and claim 15,
    An inner diameter inspection apparatus and an electrical measurement sensor, each comprising a plurality of electrode groups each including the two current electrodes and the three or more voltage detection electrodes in the axial direction.
18. In the electric measurement sensor according to claim 1 and claim 15,
    In addition to the two current electrodes, a third current electrode is formed between the two current electrodes at a position between each of the two current electrodes and sandwiching the voltage detection electrode. An inner diameter inspection device and an electric measurement sensor respectively characterized by the above.
19. In the electric measurement sensor according to claim 1 and claim 15,
    At least a part of the two current electrodes and the three or more voltage detection electrodes are formed of a metal electrode member.
20. In the inner diameter inspection apparatus and electrical measurement sensor according to claim 19,
    The electrical measurement sensor is
    An inner diameter inspection apparatus and an electric measurement, wherein the metal electrode member is an electric measurement sensor embedded in the insulating casing to form a surface substantially the same as the surface of the insulating casing. Sensor.
21. In the electric measurement sensor according to claim 1 and claim 15,
    At least a part of the two current electrodes and the three or more voltage detection electrodes are formed by winding a conductive wire constituting the conductive cable around the surface of the insulating casing. Inspection device and electrical measurement sensor.
22. In the inner diameter inspection apparatus and electrical measurement sensor according to claim 21,
    The electrical measurement sensor is
    The conductive wires forming at least a part of the two current electrodes and the three or more voltage detection electrodes are embedded in the insulating casing to form a surface substantially the same as the surface of the insulating casing. An inner diameter inspection device and an electric measurement sensor, each characterized by being an electric measurement sensor.
23. In the electric measurement sensor according to claim 1 and claim 15,
    At least a part of the two current electrodes and the three or more voltage detection electrodes are formed such that end surfaces of conductive wires constituting the conductive cable are exposed on the surface of the insulating housing. Inner diameter inspection device and electrical measurement sensor.
24. In the electric measurement sensor according to claim 1 and claim 15,
    An inner diameter inspection device and an electric measurement sensor, wherein the sheath is integrated with the insulating casing.
25. In the electric measurement sensor according to claim 1 and claim 15,
    The inner casing is filled with an insulating material different from that of the insulating casing. An inner diameter inspection device and an electric measurement sensor, respectively.
26. In the electric measurement sensor according to claim 1 and claim 15,
    An inner diameter inspection device and an electrical measurement sensor, respectively, characterized in that the insulating casing is provided with a balloon that is inflated or contracted by a gas or a liquid supplied via a pipe.
27. In the method for manufacturing an inner diameter inspection apparatus and an electric measurement sensor according to claim 22,
    The insulating casing is heat-softening resinous,
    A first step of providing first and second apertures at positions spaced apart in the axial direction of the insulating housing with respect to one electrode;
    A second step of drawing a corresponding conductive wire of the conductive cable from the first opening to the outside and winding the drawn conductive wire one layer around the insulating casing to a position where the second opening is blocked. When,
    A third step of fixing the conductive wire after inserting a conductive first fixing means into the first opening to ensure electrical connection with the conductive wire;
    A fourth step of connecting a conductive second fixing means to the end of the conductive wire wound in the second step and fixing the conductive wire in a tensioned state;
    A fifth step of embedding the conductive wire in the insulating housing by flowing a current between the first fixing unit and the second fixing unit to heat the conductive wire therebetween;
    A sixth step of removing the side of the conductive wire to which the second fixing means is connected from the second fixing means and inserting it into the second opening;
    A method for manufacturing an inner diameter inspection device and an electric measurement sensor, respectively.

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