JP2018009812A - Pressure measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure measuring device capable of measuring the pressure of a fluid in a lumen while suppressing cost increase. A pressure measuring device 110 includes a guide wire 30 that is flexible and can be inserted into the lumen of a living body. The pressure measuring device 110 is provided on the guide wire 30 and includes a support 114 having a recess 113. The pressure measuring device 110 includes a conductive rubber member 115 that is fixed to the support 114, covers at least a part of the opening of the recess 113, and changes its electric resistance value by elastic deformation. The pressure measuring device 110 includes a first electrode 121 and a second electrode 122 that are fixed to the support 114 and electrically connected to the conductive rubber member 115. [Selection diagram] FIG. 8

Description

  The present invention relates to a pressure measuring device that is inserted into a lumen of a living body and measures the pressure of a fluid in the lumen.

  As a method for measuring the pressure of fluid in the lumen of a living body, for example, blood pressure in a coronary artery, a method of inserting a guide wire having a pressure sensor into a blood vessel is known. Patent Document 1 discloses a sensor-equipped guide wire in which a sensor chip for pressure detection is arranged inside a housing provided at the distal end portion of the guide wire.

  The above-described sensor chip includes a diaphragm formed of a wafer and a piezoresistive element provided on the diaphragm. Blood pressure is applied to the diaphragm of the guide wire inserted into the blood vessel. When the diaphragm bends due to blood pressure, the electrical resistance value of the piezoresistive element changes. Here, current flows through the piezoresistive element, and the amount of current flowing through the piezoresistive element changes according to blood pressure. Based on this amount of current, the blood pressure can be calculated. In this way, blood pressure is measured by the method of inserting the guide wire into the blood vessel.

Special table 2010-540114 gazette

  The diaphragm needs to be sized to be mountable on the guide wire. On the other hand, in order to measure blood pressure with high accuracy, the diaphragm needs to be easily distorted by blood pressure. That is, the diaphragm made of a wafer needs to be formed large and thin. Therefore, the possible shape of the diaphragm and the mounting posture of the diaphragm in the guide wire are greatly limited. Therefore, the degree of freedom in designing the pressure measuring device including the diaphragm has been impaired.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to perform pressure measurement in which the degree of design freedom is ensured while enabling the pressure of the fluid in the lumen to be measured with high accuracy. Is to provide a device.

  (1) A pressure measuring device according to the present invention has a flexible guide wire that can be inserted into a lumen of a living body, a support body that is provided in the guide wire and has a recess, and the support device. A conductive rubber member that is fixed to the body, covers at least a part of the opening of the recess, and changes its electrical resistance value by elastic deformation, and is fixed to the support, and is electrically connected to the conductive rubber member. A first electrode and a second electrode connected to each other.

  According to the above configuration, when the pressure of the fluid in the lumen is applied to the conductive rubber member, the conductive rubber member is elastically deformed. Thereby, the electrical resistance value of the conductive rubber member changes. Here, the conductive rubber member can be easily elastically deformed by the pressure of the fluid in the lumen regardless of its shape. Therefore, it can prevent that the freedom degree of design of a pressure measuring device is restrict | limited by the shape of a conductive rubber member. In addition, since the first electrode and the second electrode are electrically connected to the conductive rubber member, a voltage is applied between the first electrode and the second electrode to cope with the amount of change in the electrical resistance value of the conductive rubber member. The amount of current to be obtained can be acquired via the first electrode and the second electrode. Based on this amount of current, the pressure of the fluid in the lumen can be calculated. Therefore, the pressure measuring device according to the present invention can ensure the degree of freedom of design while making it possible to measure the pressure of the fluid in the lumen with high accuracy.

  (2) Preferably, the support has a cylindrical shape and has an internal space, the axial direction of the cylindrical shape is parallel to the axial direction of the guide wire, and the concave portion is a part of the internal space. And it opens in the said axial direction, and the said electrically-conductive rubber member is arrange | positioned at the one end part of the said axial direction of the said support body.

  According to the said structure, the electrically conductive rubber member is provided in the one end part of the axial direction of a support body. Since the conductive rubber member and the support are aligned in the axial direction of the guide wire, the installation space for the conductive rubber member and the support can be prevented from expanding in the radial direction of the guide wire. Therefore, the pressure measuring device according to the present invention can realize downsizing of the pressure measuring device.

  (3) Preferably, the first electrode is electrically connected to the conductive rubber member through an internal space of the support, and the second electrode is provided on a side wall of the support to provide the conductive rubber. It is electrically connected to the member.

  (4) Preferably, the support has a cylindrical shape having a through hole in a side wall, the axial direction of the cylindrical shape is parallel to the axial direction of the guide wire, and the concave portion is the through hole, The conductive rubber member is provided outside the support in the radial direction.

  According to the said structure, the electrically conductive rubber member is provided in the radial direction outer side of the support body. Since the position where the conductive rubber member is disposed can be changed along the axial direction and the circumferential direction of the support, there is a degree of freedom in the position where the conductive rubber member is disposed. It is also possible to arrange a plurality of conductive rubber members along the axial direction of the support. Therefore, the pressure measuring device according to the present invention can increase the degree of design freedom.

  (5) Preferably, the first electrode is electrically connected to the conductive rubber member through the through hole of the support, and the second electrode is provided on a side wall of the support so as to be electrically conductive. It is electrically connected to the rubber member.

  (6) Preferably, the support includes a flat substrate.

  (7) Preferably, the guide wire has an internal space and a through hole communicating with the internal space and the outside, and the conductive rubber member is disposed in the internal space of the guide wire.

  According to the above configuration, the conductive rubber member is disposed in the internal space of the guide wire. Since the conductive rubber member does not contact the wall surface of the lumen, it is possible to prevent the conductive rubber member from being elastically deformed by contact with the wall surface. That is, it is possible to prevent a problem that contact with the wall surface is detected as a pressure change. Therefore, the pressure measuring device according to the present invention can prevent the detection accuracy of the pressure change of the fluid in the lumen from being lowered.

  ADVANTAGE OF THE INVENTION According to this invention, the pressure measuring device with which the freedom degree of design was ensured, enabling it to measure the pressure of the fluid in a lumen with high precision can be provided.

FIG. 1 is a schematic diagram of a pressure measuring device 10 according to the first embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a perspective view of the pressure sensor 11 in the pressure measuring device 10 according to the first embodiment. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is a diagram of the substrate 16 viewed from the plate thickness direction 16T. FIG. 6 is a longitudinal sectional view of a distal portion of the pressure measuring device 110 according to the second embodiment. FIG. 7 is a perspective view of the pressure sensor 11 in the pressure measuring device 10 according to the second embodiment. 8 is a sectional view taken along line VIII-VIII in FIG. FIG. 9 is a longitudinal sectional view of a distal portion of the pressure measuring device 210 according to the third embodiment. FIG. 10 is a perspective view of the pressure sensor 11 in the pressure measuring device 10 according to the third embodiment. 11 is a cross-sectional view taken along line XI-XI in FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG.

  Hereinafter, preferred embodiments of the present invention will be described. Each embodiment is only one embodiment of the present invention, and it is needless to say that the embodiment can be changed without changing the gist of the present invention.

[First Embodiment]
<Pressure measuring device 10>
As shown in FIG. 1, the pressure measuring device 10 according to the first embodiment includes a guide wire 30 and a pressure sensor 11 provided on the guide wire 30. An arithmetic control unit 40 is connected to one end of the guide wire 30. In FIG. 1, the fixed end (the end connected to the calculation control unit 40) is the proximal end (the right side in FIG. 1) and the free end is the distal end (the left side in FIG. 1). It is. Hereinafter, in the guide wire 30, the side with the proximal end is defined as the proximal side, and the side with the distal end is defined as the distal side.

  The guide wire 30 has a linear shape and can be inserted into a blood vessel (an example of a living body lumen) such as a coronary artery. The pressure sensor 11 is provided at the distal end of the guide wire 30. The calculation control unit 40 calculates blood pressure (an example of the pressure of fluid in the lumen) based on the electrical information (current value) output from the pressure sensor 11. That is, the pressure measuring device 10 is used for blood pressure measurement.

  1 and 2 show an axial center line 30L of the guide wire 30. FIG. In the present specification, directions relating to components constituting the guide wire 30, that is, an axial direction 30A, a radial direction 30R, and a circumferential direction 30C are defined as follows. The axial direction 30A, the radial direction 30R, and the circumferential direction 30C are defined based on the axial center line 30L that is straight, that is, the guide wire 30 is not bent or curved, that is, the axial center line 30L that is a straight line. ing. The axial direction 30A is a direction parallel to the axial center line 30L and includes both a distal direction and a proximal direction. The radial direction 30R is all directions orthogonal to the axial center line 30L. The circumferential direction 30C is a direction around the axial center line 30L.

<Guide wire 30>
As shown in FIGS. 1 and 2, the guide wire 30 includes a core wire 31, a tip guide portion 32, a first spiral body 33, a housing 34, a second spiral body 35, a connection wall 36, and a tip wire 37. And a guide tube 38.

  The core wire 31 is a member that constitutes the skeleton of the guide wire 30. The core wire 31 provides a certain mechanical strength against the bending of the guide wire 30 so that the guide wire 30 can be inserted into the blood vessel without bending. The core wire 31 is a cylindrical wire and extends from the proximal end to the distal side. The material of the core wire 31 is, for example, a medical stainless steel rope. The axis line of the core wire 31 is parallel to the axis line 30L.

  The core wire 31 is more flexible at the distal side than at the proximal side. The form of the core wire 31 is not particularly limited. For example, the small-diameter portion 31a located on the distal side, the large-diameter portion 31b located on the proximal side, and the tapered portion 31c connecting the small-diameter portion 31a and the large-diameter portion 31b. Have The small diameter part 31a and the large diameter part 31b each have a constant outer diameter, and the outer diameter of the large diameter part 31b is larger than the outer diameter of the small diameter part 31a. The outer diameter of the tapered portion 31c is equal to the outer diameter of the large diameter portion 31b at the proximal end, gradually decreases from the proximal end toward the distal end, and equal to the outer diameter of the small diameter portion 31a at the distal end. As the outer diameter of the core wire 31 gradually decreases toward the distal side, the rigidity of the core wire 31 decreases in the order of the large diameter portion 31b, the tapered portion 31c, and the small diameter portion 31a.

  The tip guide portion 32 is disposed at the distal end of the guide wire 30. The distal end guide portion 32 is a portion that guides the traveling direction of the guide wire 30 along the blood vessel by contacting the blood vessel wall when the guide wire 30 is inserted into the blood vessel. The tip guide part 32 includes, for example, a hemispherical part 32a located on the distal side and a cylindrical part 32b extending proximally from the hemispherical part 32a, although the form thereof is not particularly limited. The hemispherical portion 32a has a hemispherical shape protruding distally so as not to damage the blood vessel wall. The outer diameter of the hemispherical portion 32 a is substantially equal to the outer diameter of the second spiral body 35. The cylindrical portion 32b protrudes proximally from the hemispherical portion 32a and has a cylindrical shape with an outer diameter smaller than the outer diameter of the hemispherical portion 32a. By inserting the cylindrical portion 32b into the second spiral body 35, the tip guide portion 32 is positioned with respect to the second spiral body 35, and the outer surfaces of the hemispherical portion 32a and the second spiral body 35 are smoothly continuous without a step. The material of the distal end guide portion 32 is, for example, medical stainless steel.

  Although the form is not particularly limited on the distal side of the guide wire 30, for example, a first spiral body 33 and a second spiral body 35 are provided. The first spiral body 33 and the second spiral body 35 are weaker in bending rigidity than the core wire 31, that is, easily bent. The first spiral body 33 is configured by a wire wound in a spiral shape. The material of the first spiral 33 is, for example, a medical stainless steel rope. The axial center line of the first spiral body 33 is parallel to the axial center line 30L. The small diameter portion 31 a of the core wire 31 is inserted into the first spiral body 33. The first spiral 33 has a proximal end 33a and a distal end 33b. The proximal end portion 33a is fixed to the outer peripheral surface of the small diameter portion 31a of the core wire 31 by, for example, laser welding or an adhesive. Thereby, the bending rigidity of the first spiral body 33 is reinforced by the core wire 31.

  The housing 34 is a housing that houses the pressure sensor 11 in the internal space 34S. The housing 34 has a cylindrical shape and has the internal space 34S. The material of the housing 34 is, for example, a medical stainless steel rope. The axis line of the housing 34 is parallel to the axis line 30L. The small diameter portion 31 a of the core wire 31 is inserted into the proximal end portion of the housing 34. A distal end portion 33b of the first spiral body 33 is fixed to the proximal end portion of the housing 34 by, for example, laser welding or an adhesive.

  The housing 34 has a plurality of through holes 34a. In the present embodiment, the housing 34 has two through holes 34a. The through hole 34a passes through the cylindrical wall of the housing 34 along the radial direction 30R. The internal space 34S of the housing 34 communicates with the outside through the through hole 34a. The two through holes 34a are arranged along the circumferential direction 30C of the guide wire 30 with an interval of 180 degrees around the axis 30L.

  The second spiral body 35 is configured by a wire wound in a spiral shape. The material of the second spiral body 35 is, for example, a medical stainless steel rope. The axial center line of the second helical body 35 is parallel to the axial center line 30L. The second spiral 35 has a proximal end 35a and a distal end 35b. The proximal end portion 35 a of the second spiral body 35 is fixed to the distal end portion of the housing 34. The second spiral body 35 and the housing 34 are fixed by, for example, laser welding or an adhesive. The cylindrical portion 32 b of the tip guide portion 32 is inserted into the distal end portion 35 b of the second spiral body 35. The distal end portion 35b is fixed to the outer peripheral surface of the cylindrical portion 32b. The second spiral body 35 and the tip guide portion 32 are fixed by, for example, laser welding or an adhesive.

  The connecting wall 36 is a member for connecting the tip wire 37 to the housing 34. The connecting wall 36 is fixed to the distal end of the housing 34. The connecting wall 36 is made of, for example, a metal solder material.

  The tip wire 37 reinforces the bending rigidity of the second spiral body 35. The tip wire 37 is, for example, a medical stainless steel wire. The axial center line of the tip wire 37 is parallel to the axial center line 30L. The proximal end of the tip wire 37 is fixed to the connecting wall 36. The distal end portion of the tip wire 37 is fixed to the cylindrical portion 32b of the tip guide portion 32 by, for example, laser welding or an adhesive.

  The guide tube 38 has a cylindrical shape. The guide tube 38 is located outside the radial direction 30R of the small diameter portion 31a of the core wire 31, and covers the proximal side portion of the small diameter portion 31a. The axial center line of the guide tube 38 is parallel to the axial center line 30L. The guide tube 38 is fixed to the outer peripheral surface of the small diameter portion 31 a of the core wire 31. The guide tube 38 has flexibility. The guide tube 38 is, for example, a medical synthetic resin, and is thermally welded to the outer peripheral surface of the core wire 31, for example.

  With the above-described configuration, the core wire 31 and the tip guide portion 32 are connected via the first spiral body 33, the housing 34, and the second spiral body 35. The housing 34 and the tip guide portion 32 are connected via a tip wire 37. Since the core wire 31 is inserted into the first spiral body 33 and the housing 34, the first spiral body 33 and the housing 34 are supported by the core wire 31. On the other hand, the tip guide portion 32 is fixed to a tip wire 37 fixed to the housing 34, so that the tip guide portion 32 is supported by the housing 34. That is, the tip guide portion 32 is supported by the core wire 31 via the housing 34 and the tip wire 37. In this way, the guide wire 30 itself (excluding the core wire 31) is supported by the core wire 31 and is given mechanical strength.

  With such a configuration, when an operation of feeding the guide wire 30 to the blood vessel is performed at the proximal end, the guide wire 30 advances in the blood vessel without bending, following this operation. Further, when the distal end guide portion 32 comes into contact with the blood vessel wall, the guide wire 30 is bent along the blood vessel wall.

<Pressure sensor 11>
As shown in FIG. 2, the pressure sensor 11 is disposed in the internal space 34 </ b> S of the housing 34.

  As shown in FIGS. 2 to 5, the pressure sensor 11 includes a support 14 having a recess 13, a conductive rubber member 15 provided on the support 14, a first electrode 21 provided on the support 14, and A second electrode 22.

  The support 14 includes a flat plate-shaped substrate 16 and a columnar connection member 17 fixed to the substrate 16.

  As shown in FIGS. 3 and 4, the substrate 16 has a pair of main surfaces (first main surfaces 16a) positioned on opposite sides in the thickness direction 16T of the substrate 16 (direction perpendicular to the paper surface in FIG. 5). And a second main surface 16b). The plate thickness direction 16T is one of the radial directions 30R of the guide wire 30. FIG. 5 shows the substrate 16, and as shown in FIG. 5, the first main surface 16a and the second main surface 16b have a rectangular outer shape when viewed from the thickness direction. The longitudinal directions of the first main surface 16a and the second main surface 16b are parallel to the axial center line 30L.

  As shown in FIGS. 3 and 4, the connection member 17 includes a cylindrical tube 71 and a closing wall 72 that closes the opening at the distal end of the tube 71. The axial line of the cylinder 71 is parallel to the axial line 30L. A proximal portion of the substrate 16 is disposed inside the cylinder 71. The closing wall 72 fills the space between the substrate 71 and the cylinder 71 disposed inside the connection member 17 at the distal end of the cylinder 71. In the present embodiment, the closing wall 72 fills the entire inside of the cylindrical body 71. The closing wall 72 prevents blood in the blood vessel from flowing into the connecting member 17 from the through hole 34 a of the housing 34. The substrate 16 is fixed to the connection member 17 through the closing wall 72. The connecting member 17 is inserted into the small diameter portion 31 a of the core wire 31. The cylindrical body 71 is fixed to the small diameter portion 31 a using, for example, an adhesive so that the connecting member 17 does not move with respect to the core wire 31. An adhesive or other filler is filled between the outer peripheral surface of the cylindrical body 71 and the inner peripheral surface of the small diameter portion 31 a of the core wire 31, and the space between the connecting member 17 and the core wire 31 is sealed.

  As shown in FIGS. 4 and 5, the substrate 16 has a recess 13 that opens to the first major surface 16 a. The recess 13 has a rectangular opening edge viewed from the thickness direction 16T of the substrate 16. The recess 13 has a certain depth in the thickness direction 16T of the substrate 16.

  As shown in FIGS. 2 to 5, the conductive rubber member 15 is fixed to the first main surface 16 a of the substrate 16 using, for example, an adhesive. In the first embodiment, the conductive rubber member 15 has a rectangular parallelepiped shape. As shown in FIG. 5, the outer dimensions (rectangular vertical dimension and horizontal dimension) of the conductive rubber member 15 viewed from the thickness direction 16T of the substrate 16 are the outer dimensions of the recess 13 (vertical dimension and horizontal dimension of the opening). Bigger than. Therefore, the conductive rubber member 15 covers the opening of the recess 13.

  The conductive rubber member 15 is a rubber member configured such that the electric resistance value changes according to the deformation amount. In the conductive rubber member 15, conductive particles (carbon, metal powder, metal deposition powder, etc.) are dispersed substantially uniformly in a highly insulating rubber material such as silicon rubber so as to have a predetermined density. . In such a configuration, since most of the conductive particles are not in contact with each other in the non-pressurized state, the conductive particles are not electrically connected to each other, and no conduction path is formed in the conductive rubber member 15. Therefore, the electrical resistance value of the conductive rubber member 15 is kept very high. On the other hand, when the conductive rubber member 15 is deformed by being pressurized, some of the conductive particles come into contact with each other, and a conduction path is formed in the conductive rubber member 15. As the applied pressure increases (that is, the amount of deformation increases), the number of conductive particles that come into contact with each other increases, and when the number or thickness of the conduction paths increases, the electrical resistance value decreases in proportion to the amount of deformation. . On the other hand, when the external force is released and the conductive rubber member 15 returns to the non-pressurized state elastically, most of the conductive particles return to the non-contact state, and the electric resistance value becomes high again. In summary, the deformation amount of the conductive rubber member 15 increases and decreases in proportion to the increase and decrease of the pressure applied to the conductive rubber member 15, thereby decreasing and increasing the electrical resistance value of the conductive rubber member 15.

  As shown in FIG. 5, the first electrode 21 and the second electrode 22 are fixed to the first major surface 16a. In the first embodiment, the first electrode 21 and the second electrode 22 are formed on the first main surface 16a as a conductor pattern by printing. The first electrode 21 and the second electrode 22 are electrically connected to the conductive rubber member 15. As shown in FIG. 4, the first electrode 21 and the second electrode 22 are located between the conductive rubber member 15 and the substrate 16. The first electrode 21 and the second electrode 22 are electrically connected to each other through the conductive rubber member 15.

  2 and 4, the surface of the conductive rubber member 15 includes an exposed surface 15a exposed in the internal space 34S of the housing 34 and a non-exposed surface 15b that faces the substrate 16 and is not exposed in the internal space 34S. Have

  As shown in FIG. 2, the internal space 34 </ b> S of the housing 34 communicates with the outside of the guide wire 30 through the through hole 34 a of the housing 34. When the guide wire 30 is inserted into the blood vessel, blood in the blood vessel flows into the internal space 34S. At this time, the blood pressure in the internal space 34 </ b> S of the housing 34 is applied to the exposed surface 15 a of the conductive rubber member 15. In the present specification, when the atmospheric pressure is set to the reference pressure and only the atmospheric pressure is applied to the exposed surface 15a of the conductive rubber member 15, the state of the conductive rubber member 15 is in a non-pressurized state. On the other hand, when the guide wire 30 is inserted into the blood vessel, blood pressure is applied to the exposed surface 15a, and the conductive rubber member 15 is in a pressurized state.

  When blood pressure is applied to the exposed surface 15a, the conductive rubber member 15 is elastically deformed thereby. In this elastic deformation, a part of the conductive rubber member 15 contracts, and a part of the conductive rubber member 15 including the non-exposed surface 15 b enters the recess 13. As a result of such deformation, as described above, the electrical resistance value of the conductive rubber member 15 decreases and increases as the deformation amount of the conductive rubber member 15 increases and decreases. From this, the pressure acting on the conductive rubber member 15 can be obtained based on the electric resistance value of the conductive rubber member 15.

<Calculation control unit 40>
As shown in FIG. 1, the arithmetic control unit 40 includes a first conductive line 18 and a second conductive line 19 that are electrically connected to the pressure sensor 11, a power supply unit 41 that supplies current to the pressure sensor 11, It has the calculating part 42 which arithmetically processes the electrical information output from the pressure sensor 11, and the connector 43 connected to the 1st conductive wire 18 and the 2nd conductive line 19.

  As shown in FIGS. 3 to 5, the first conductive line 18 is electrically connected to the first electrode 21. The second conductive line 19 is electrically connected to the second electrode 22.

  As shown in FIG. 1, the power supply unit 41 is configured to cause a current to flow through the pressure sensor 11 through the connector 43, the first conductive line 18, and the second conductive line 19.

  The computing unit 42 acquires electrical information output from the pressure sensor 11, that is, a change in the amount of current flowing through the pressure sensor 11 through the first conductive line 18, the second conductive line 19, and the connector 43. The calculator 42 calculates the blood pressure acting on the pressure sensor 11 based on the acquired change in the amount of current. The calculation unit 42 includes a bridge circuit unit 42a and a memory 42b. More specifically, the calculation unit 42 calculates the blood pressure as follows.

  Since the change in the amount of current due to the change in the electrical resistance value is minute, this change in the current value is converted into a change in the voltage value (hereinafter, output voltage value) output from the Wheatstone bridge circuit, and the change in the voltage value The blood pressure is calculated based on the above. The bridge circuit unit 42 a of the calculation unit 42 forms a Wheatstone bridge circuit together with the conductive rubber member 15. In the Wheatstone bridge circuit, the ratio of the output voltage to the input voltage increases as the change in the electric resistance value of one resistor constituting the Wheatstone bridge circuit increases. If the input voltage is constant, the output voltage will increase. Therefore, the output voltage value increases and decreases as the electrical resistance value of the conductive rubber member 15 increases and decreases.

  The memory 42b stores the correspondence relationship between the above-described output voltage value and blood pressure as, for example, one-to-one correspondence data. Therefore, when the output voltage value is obtained, the calculation unit 42 can specify the blood pressure corresponding to the output voltage value based on the correspondence relationship stored in the memory 42b. In this way, the calculation unit 42 can calculate the blood pressure acting on the pressure sensor 11 based on the electrical information output from the pressure sensor 11.

  The pressure sensor 11 outputs electrical information corresponding to the blood pressure change in the blood vessel acting on the pressure sensor 11. As shown in FIG. 2, the pressure sensor 11 includes a first conductive line 18 and a second conductive line 19 that are electrically connected to the calculation control unit 40. The electrical information output from the pressure sensor 11 is transmitted to the arithmetic control unit 40 via the first conductive line 18 and the second conductive line 19.

<Usage example of pressure measuring device 10>
The pressure measuring device 10 is used for measuring blood pressure in a coronary artery, for example. The guide wire 30 is inserted into the coronary artery with the distal end provided with the tip guide portion 32 as the head in the direction of insertion into the blood vessel. The position of the guide wire 30 in the coronary artery is grasped based on the position of the distal end guide portion 32 displayed on the X-ray fluoroscopic image of the blood vessel.

  When the pressure sensor 11 reaches the blood pressure measurement position in the coronary artery, the insertion of the guide wire 30 is interrupted. In such a state, a constant current is supplied from the power supply unit 41 to the conductive rubber member 15 through the first conductive line 18 and the second conductive line 19 by a user operation.

  In the blood vessel, blood flows into the internal space 34S of the housing 34, and blood pressure acts on the surface of the conductive rubber member 15. Thereby, the conductive rubber member 15 is elastically deformed.

  In the blood flow, pulsations in which blood pressure rises and falls repeatedly due to the movement of the heart are generated. The conductive rubber member 15 is elastically deformed following the blood flow pulsation. Thereby, the electrical resistance value of the deformed portion of the conductive rubber member 15 changes corresponding to the blood pressure of the pulsating blood flow.

  The calculation unit 42 of the calculation control unit 40 acquires electrical information output from the pressure sensor 11 through the first conductive line 18 and the second conductive line 19. As described above, the calculation unit 42 calculates the blood pressure acting on the pressure sensor 11 based on this electrical information.

<Operational effects of the first embodiment>
According to the pressure measuring device 10 according to the first embodiment, when the pressure of the fluid (blood) in the lumen (blood vessel) is applied to the conductive rubber member 15, the conductive rubber member 15 is elastically deformed. As a result, the electric resistance value of the conductive rubber member 15 changes. Here, the conductive rubber member 15 can be easily elastically deformed by the pressure of the fluid in the lumen regardless of its shape. Therefore, it is possible to prevent the degree of freedom in designing the pressure measuring device 10 from being limited by the shape of the conductive rubber member 15. In addition, since the first electrode 21 and the second electrode 22 are electrically connected to the conductive rubber member 15, the electric resistance of the conductive rubber member 15 can be obtained by applying a voltage between the first electrode 21 and the second electrode 22. The amount of current corresponding to the amount of change in value can be acquired via the first electrode 21 and the second electrode 22. Based on this amount of current, the pressure of the fluid in the lumen can be calculated. Therefore, the pressure measuring device 10 can ensure the degree of design freedom while enabling the pressure of the fluid in the lumen to be measured with high accuracy.

  According to the pressure measuring device 10, the conductive rubber member 15 covers the opening of the recess 13. Therefore, when pressure is applied, the conductive rubber member 15 is elastically deformed so that a part of the conductive rubber member 15 enters the recess 13. Since the recess 13 exists, the conductive rubber member 15 is easily elastically deformed. The change in the electric resistance value due to the pressure change becomes large. Therefore, in the pressure measuring device 10, the measurement accuracy of the pressure change is improved.

  According to the pressure measuring device 10, the conductive rubber member 15 is disposed in the internal space 34 </ b> S of the housing 34 (internal space of the guide wire 30). Since the conductive rubber member 15 does not contact the wall surface of the lumen, it is possible to prevent the conductive rubber member 15 from being elastically deformed by contact with the wall surface. That is, it is possible to prevent a problem that contact with the wall surface is detected as a pressure change. Therefore, the pressure measuring device 10 can prevent the detection accuracy of the pressure change of the fluid in the lumen from being lowered.

[Second Embodiment]
<Pressure measuring device 110>
A pressure measurement device 110 according to the second embodiment will be described with reference to FIGS. 6 to 8. The pressure measurement device 110 according to the second embodiment is different from the pressure measurement device 10 according to the first embodiment in the configuration of the pressure sensor 111. In other respects, the second embodiment is the same as the first embodiment. Below, the structure of the pressure sensor 111 which concerns on 2nd Embodiment is demonstrated.

  As shown in FIG. 6, the pressure sensor 111 is disposed in the internal space 34 </ b> S of the housing 34.

  As shown in FIGS. 6 and 7, the pressure sensor 111 is provided at the sensor body 112, the conductive rubber member 115 provided at the distal end portion of the sensor body 112, and the proximal end portion of the sensor body 112. And a first electrode 121 provided in the internal space 112S of the sensor body 112 and extending proximally.

  As shown in FIGS. 6 to 8, the sensor body 112 has a cylindrical shape. The axial center line of the sensor body 112 is parallel to the axial center line 30L. A proximal portion of the sensor body 112 is inserted into the small diameter portion 31 a of the core wire 31. The sensor body 112 is fixed to the small diameter portion 31a by using, for example, laser welding or an adhesive so that the sensor body 112 does not move with respect to the core wire 31. Between the outer peripheral surface of the sensor main body 112 and the inner peripheral surface of the small-diameter portion 31a of the core wire 31, an adhesive or other filler used for the above-described fixing is filled, and the gap between the sensor main body 112 and the core wire 31 is filled. It is sealed.

  As shown in FIG. 8, the sensor body 112 has an internal space 112S. The internal space 112 </ b> S includes a recess 113 that opens to the distal end of the sensor body 112, and an axial space 116 that extends from the recess 113 to the proximal side and opens to the proximal end of the sensor body 112. The length of the axial space 116 in the axial direction 30A is longer than the length of the recess 113 in the axial direction 30A.

  The sensor body 112 includes a first inner peripheral surface 118 located at the distal end portion and a second inner peripheral surface 119 located more proximal than the first inner peripheral surface 118. In the sensor main body 112, the inner diameter of the position corresponding to the first inner peripheral surface 118 (recess 113) is larger than the inner diameter of the position corresponding to the second inner peripheral surface 119 (axial space 116). The inner diameter in the recess 113 is constant, and the inner diameter in the axial space 116 is constant. The sensor body 112 includes a first distal end surface 125 located at the distal end, and a second distal end surface 126 connecting the first inner peripheral surface 118 and the second inner peripheral surface 119. The recess 113 is defined by the first inner peripheral surface 118 and the second distal end surface 126. The axial space 116 is defined by the second inner peripheral surface 119.

  As shown in FIG. 8, the sensor main body 112 includes a cylindrical support body 114 and a layered second electrode 122 fixed to a part of the surface of the support body 114. The surface of the sensor body 112 excluding the second inner peripheral surface 119 is constituted by the surface of the second electrode 122. The second inner peripheral surface 119 is configured by the surface of the support body 114. The second electrode 122 is formed on the support 114 by, for example, electroforming. The material of the support 114 is, for example, cobalt (Co), and the material of the second electrode 122 is, for example, gold (Au). As shown in FIGS. 6 to 8, the second electrode 122 is electrically connected to the second conductive line 19.

  The conductive rubber member 115 is fixed to the sensor main body 112 using, for example, a conductive adhesive.

  The conductive rubber member 115 includes an exposed portion 151 located on the distal side and a protruding portion 152 extending from the exposed portion 151 to the proximal side. The exposed portion 151 is exposed in the internal space 34 </ b> S of the housing 34. The exposed portion 151 covers the opening to the distal side of the recess 113. The shape of the exposed portion 151 is a hemispherical shape protruding to the distal side. The outer diameter of the exposed portion 151 is substantially equal to the outer diameter of the sensor body 112. The protruding portion 152 protrudes proximally from the exposed portion 151 and has a cylindrical shape with an outer diameter smaller than the outer diameter of the exposed portion 151.

  The exposed portion 151 has a hemispherical exposed surface 151a and an annular non-exposed surface 151b. The exposed surface 151a is located on the distal side in the axial direction 30A, and the unexposed surface 151b is located on the proximal side. The entire exposed surface 151 a is exposed in the internal space 34 </ b> S of the housing 34. A conductive adhesive or other conductive filler is filled between the non-exposed surface 151b and the first distal end surface 125, and the gap between the conductive rubber member 115 and the sensor body 112 is sealed. ing. The non-exposed surface 151b is mechanically connected to the first distal end surface 125 via a conductive adhesive or other conductive filler. Since the first distal end surface 125 of the sensor body 112 is the surface of the second electrode 122, the exposed portion 151 is electrically connected to the second electrode 122.

  The protrusion 152 is in contact with the first inner peripheral surface 118 and the second distal end surface 126 in the recess 113. Since the first inner peripheral surface 118 and the second distal end surface 126 of the sensor body 112 are surfaces of the second electrode 122, the protrusion 152 is electrically connected to the second electrode 122. The protrusion 152 has a concave surface 152a that is recessed distally at a portion that intersects the axial center line 30L on the proximal end surface.

  The first electrode 121 includes an electrode body 127 and an insulating cylinder 128 that covers the electrode body 127. The electrode body 127 has an elongated cylindrical shape. The axis of the electrode body 127 is parallel to the axis 30L. The material of the electrode body 127 is a conductive material, for example, copper (Cu). The insulating cylinder 128 has a cylindrical shape, and the axis of the insulating cylinder 128 is parallel to the axis 30L. The material of the insulating cylinder 128 is a resin material having electrical insulation, for example, polyimide. The insulating cylinder 128 covers the outer peripheral surface of the electrode body 127 except for both end portions in the axial direction 30A. The insulating cylinder 128 is fixed to the electrode body 127 by, for example, heat welding.

  The insulating cylinder 128 is disposed in the axial space 116 and extends more proximally than the sensor body 112. The outer peripheral surface of the insulating cylinder 128 is in contact with the second inner peripheral surface 119 of the sensor main body 112. Since the electrode body 127 and the sensor body 112 are separated by the insulating cylinder 128, they are electrically insulated from each other. The distal end of the electrode main body 127 is electrically connected to the concave surface 152 a of the conductive rubber member 115. As shown in FIGS. 6 to 8, the electrode body 127 is electrically connected to the first conductive line 18.

  As shown in FIGS. 6 and 8, the fixing wall 124 covers the proximal end surface of the sensor body 112 and a part of the outer peripheral surface of the insulating cylinder 128 projecting proximally from the sensor body 112. ing. The shape of the fixed wall 124 is a hemispherical shape protruding to the proximal side. The insulating cylinder 128 is fixed to the sensor body 112 (support 114) by the fixed wall 124. The fixed wall 124 seals between the insulating cylinder 128 and the sensor main body 112. The fixed wall 124 is made of, for example, an adhesive.

<Usage example of pressure measuring device 110>
The pressure measurement device 110 according to the second embodiment is used to measure blood pressure in a coronary artery, for example, similarly to the pressure measurement device 10 according to the first embodiment. In a state where the guide wire 30 is inserted into the coronary artery, a constant current is supplied to the conductive rubber member 115 from the power source 41 through the first conductive line 18 and the second conductive line 19 by a user operation.

  In the blood vessel, blood flows into the internal space 34S of the housing 34, and blood pressure acts on the exposed surface 151a of the conductive rubber member 115. Thereby, the conductive rubber member 115 contracts and elastically deforms. As a result of such elastic deformation, the electrical resistance value of the conductive rubber member 115 changes as described above. Corresponding to the blood pressure of the pulsating blood flow, the electrical resistance value of the conductive rubber member 115 changes.

  The calculation unit 42 of the calculation control unit 40 acquires electrical information output from the pressure sensor 111 through the first conductive line 18 and the second conductive line 19. As described above, the calculation unit 42 calculates the blood pressure acting on the pressure sensor 111 based on this electrical information.

<Effects of Second Embodiment>
Also in the pressure measurement device 110 according to the second embodiment, as in the first embodiment, when the pressure of the fluid (blood) in the lumen (blood vessel) is applied to the conductive rubber member 115, the conductive rubber member 115 is elastically deformed. To do. Regardless of its shape, the conductive rubber member 115 can be easily elastically deformed by the pressure of the fluid in the lumen. Therefore, the pressure measuring device 110 according to the second embodiment can ensure the degree of design freedom while enabling the pressure of the fluid in the lumen to be measured with high accuracy, as in the first embodiment.

  According to the pressure measuring device 110, the conductive rubber member 115 is provided at one end portion (distal end portion) of the support body 114 in the axial direction. Since the conductive rubber member 115 and the support body 114 are arranged in the axial direction 30A of the guide wire 30, it is possible to prevent the installation space for the conductive rubber member 115 and the support body 114 from expanding in the radial direction 30R of the guide wire 30. Therefore, the pressure measuring device 110 can realize a compact size of the pressure measuring device 110.

  According to the pressure measuring device 110, the conductive rubber member 115 is disposed in the internal space 34S of the housing 34 (the internal space of the guide wire 30). Therefore, the pressure measuring device 110 can prevent the detection accuracy of the pressure change of the fluid in the lumen from being lowered, as in the first embodiment.

[Third Embodiment]
<Pressure measuring device 210>
With reference to FIGS. 9 to 12, a pressure measuring apparatus 210 according to the third embodiment will be described. The pressure measurement device 210 according to the third embodiment is different from the pressure measurement device 10 according to the first embodiment in the configuration of the pressure sensor 211. In other respects, the third embodiment is the same as the first embodiment. Below, the structure of the pressure sensor 211 which concerns on 3rd Embodiment is demonstrated.

  As shown in FIG. 9, the pressure sensor 211 is disposed in the internal space 34 </ b> S of the housing 34.

  As shown in FIGS. 9 and 10, the pressure sensor 211 includes a sensor main body 212, a closing wall 227 provided at the distal end of the sensor main body 212, and a conductive rubber provided on the outer peripheral surface of the sensor main body 212. A member 215 and a first electrode 221 provided in the internal space 212S of the sensor body 212 and extending proximally are provided.

  As shown in FIGS. 9 to 12, the sensor body 212 has a cylindrical shape. The axial center line of the sensor body 212 is parallel to the axial center line 30L. A proximal portion of the sensor body 212 is inserted into the small diameter portion 31 a of the core wire 31. The sensor body 212 is fixed to the small-diameter portion 31a using, for example, laser welding or an adhesive so that the sensor body 212 does not move relative to the core wire 31. Between the outer peripheral surface of the sensor main body 212 and the inner peripheral surface of the small diameter portion 31 a of the core wire 31, an adhesive or other filler used for the above-described fixing is filled, and the gap between the sensor main body 212 and the core wire 31 is filled. It is sealed.

  As shown in FIG. 11, the sensor body 212 has an internal space 212S. The internal space 212S includes an axial space 216 that opens to the distal end and the proximal end of the sensor body 112, and a through hole 213 that penetrates the side wall of the sensor body 212 in the radial direction 30R. The through hole 213 is a recess formed in the side wall of the sensor main body 212 (support 214).

  As shown in FIG. 11, the sensor main body 212 includes a cylindrical support body 214 and a layered second electrode 222 fixed to the outer peripheral surface of the support body 214. The second electrode 222 is formed on the support 214 by, for example, electroforming. The material of the support 214 is, for example, polyimide, and the material of the second electrode 222 is, for example, gold (Au). As shown in FIGS. 9 to 12, the second electrode 222 is electrically connected to the second conductive line 19.

  As shown in FIGS. 11 and 12, the conductive rubber member 215 is provided at a position corresponding to the through hole 213, that is, at a position closing the through hole 213. The conductive rubber member 215 is disposed at the center of the sensor body 212 in the axial direction 30A.

  The conductive rubber member 215 includes a cylindrical exposed portion 251 and a columnar protruding portion 252 that protrudes from the exposed portion 251 into the through hole 213. The exposed portion 251 covers the opening of the through hole 213 to the outside in the radial direction 30R.

  The conductive rubber member 215 is fixed to the outer peripheral surface of the sensor main body 212. In the third embodiment, a conductive rubber member 215 is formed on the outer peripheral surface of the sensor body 212 by dipping a conductive rubber material.

  As shown in FIG. 9, the exposed portion 251 is exposed in the internal space 34 </ b> S of the housing 34. As shown in FIGS. 11 and 12, the exposed portion 251 has an exposed surface 251a and a non-exposed surface 251b. The exposed surface 251a is a surface exposed to the internal space 34S of the housing 34 in the exposed portion 251. The exposed surface 251a is the outer peripheral surface of the exposed portion 251 and both end surfaces in the axial direction 30A. On the other hand, the non-exposed surface 251b is an inner peripheral surface of the exposed portion 251. The non-exposed surface 251b is in contact with the outer peripheral surface of the sensor main body 212. Since the outer peripheral surface of the sensor body 212 is the outer peripheral surface of the second electrode 222, the exposed portion 251 is electrically connected to the second electrode 222.

  As shown in FIGS. 10 to 12, the shape of the first electrode 221 is a cylindrical shape. The axis of the first electrode 221 is parallel to the axis 30L. The outer peripheral surface of the first electrode 221 is in contact with the inner peripheral surface of the support 214. The first electrode 221 is fixed to the support 214 using, for example, laser welding or an adhesive.

  As shown in FIG. 11, the protruding portion 252 of the conductive rubber member 215 is in contact with the outer peripheral surface of the first electrode 221. Therefore, the first electrode 221 is electrically connected to the conductive rubber member 215. The first electrode 221 is electrically connected to the first conductive line 18.

  As shown in FIGS. 9 and 11, the closing wall 227 covers the distal end surface of the sensor body 212 and the distal end surface of the first electrode 221. A conductive adhesive or other filler is filled between the closing wall 227 and the sensor body 212, and the space between the closing wall 227 and the sensor body 212 is sealed. By the closing wall 227, the internal space 212S of the sensor body 212 is closed from the distal side. The closing wall 227 is made of, for example, an adhesive.

<Usage example of pressure measuring device 210>
Similar to the pressure measurement device 10 according to the first embodiment, the pressure measurement device 210 according to the third embodiment is used, for example, to measure blood pressure in a coronary artery. In a state where the guide wire 30 is inserted into the coronary artery, a constant current is supplied to the conductive rubber member 215 from the power source 41 through the first conductive line 18 and the second conductive line 19 by a user operation.

  In the blood vessel, blood flows into the internal space 34S of the housing 34, and blood pressure acts on the exposed surface 251a of the conductive rubber member 215. As a result, the conductive rubber member 215 contracts and elastically deforms. As a result of such elastic deformation, the electrical resistance value of the conductive rubber member 215 changes as described above. Corresponding to the blood pressure of the pulsating blood flow, the electrical resistance value of the conductive rubber member 215 changes.

  The calculation unit 42 of the calculation control unit 40 acquires electrical information output from the pressure sensor 211 through the first conductive line 18 and the second conductive line 19. As described above, the calculation unit 42 calculates the blood pressure acting on the pressure sensor 211 based on this electrical information.

<Operational effects of the third embodiment>
Also in the pressure measurement device 210 according to the third embodiment, as in the first embodiment, when the pressure of the fluid (blood) in the lumen (blood vessel) is applied to the conductive rubber member 215, the conductive rubber member 215 is elastically deformed. To do. Regardless of its shape, the conductive rubber member 215 can be easily elastically deformed by the pressure of the fluid in the lumen. Therefore, the pressure measuring device 210 according to the third embodiment can ensure the degree of freedom of design while enabling the pressure of the fluid in the lumen to be measured with high accuracy, as in the first embodiment.

  According to the pressure measuring device 210, the conductive rubber member 215 is provided outside the support body 214 in the radial direction 30 </ b> R. Since the position where the conductive rubber member 215 is disposed can be changed along the axial direction 30A and the circumferential direction 30C of the support 214, there is a degree of freedom in the position where the conductive rubber member 215 is disposed. It is also possible to arrange the plurality of conductive rubber members 215 along the axial direction 30 </ b> A of the support body 214. Therefore, the pressure measuring device 210 can increase the degree of design freedom.

  According to the pressure measuring device 210, the conductive rubber member 215 is disposed in the internal space 34S of the housing 34 (the internal space of the guide wire 30). Therefore, the pressure measuring device 210 can prevent the detection accuracy of the pressure change of the fluid in the lumen from being lowered, as in the first and second embodiments.

[Modification]
As mentioned above, although embodiment of this invention has been described in detail, the above description is only illustration of this invention in all the points. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. Regarding each component of the pressure measuring devices 10, 110, and 210 according to the first to third embodiments, the component may be omitted, replaced, and added as appropriate according to the embodiment. In addition, the shape and size of each component of the pressure measuring devices 10, 110, and 210 may be set as appropriate according to the embodiment. For example, the following changes can be made.

  In the first embodiment, the support 14 includes a cylindrical cylinder 71. In the second embodiment, the support 114 has a cylindrical shape. In the third embodiment, the support 214 has a cylindrical shape. In the first to third embodiments, at least a part of the shape of the support is configured in a columnar shape or a cylindrical shape so that the support can be inserted into the core wire 31. The support body should just be fixable to the core wire 31 directly or indirectly, and the shape of a support body is not limited. The shape of the support may be a plate shape or other shapes.

  In the first embodiment, the conductive rubber member 15 covers the entire opening of the recess 13. In the second embodiment, the conductive rubber member 115 covers the entire opening of the recess 113. In the third embodiment, the conductive rubber member 215 covers the entire opening of the recess (through hole 213). The conductive rubber member does not need to cover the entire opening of the concave portion, and may cover at least a part of the opening of the concave portion.

  In the first embodiment, the shape of the conductive rubber member 15 is a rectangular parallelepiped shape. In the second embodiment, the conductive rubber member 115 includes a hemispherical exposed portion 151 and a columnar protruding portion 152. In the third embodiment, the conductive rubber member 215 has a cylindrical shape. As long as the conductive rubber member covers the opening of the recess, the shape of the conductive rubber member is not limited. In particular, in the third embodiment, the conductive rubber member 215 may be disposed outside the radial direction 30R of the support body 214, and the shape of the conductive rubber member 215 is not limited. The shape of the conductive rubber member 215 may be, for example, a disk shape or a plate shape.

  In the first embodiment, the conductive rubber member 15 is directly fixed to the support 14. In the second embodiment, the conductive rubber member 115 is indirectly fixed to the support body 114 via the second electrode 122. Similarly, in the third embodiment, the conductive rubber member 215 is indirectly fixed to the support body 214 via the second electrode 122. The conductive rubber member may be directly fixed to the support or indirectly fixed.

  In the first embodiment, the first electrode 21 and the second electrode 22 are directly fixed to the substrate 16 (support 14). In the second embodiment, the first electrode 121 and the second electrode 122 are directly fixed to the sensor body 112. In the third embodiment, the first electrode 221 and the second electrode 222 are directly fixed to the sensor body 212. The first electrode and the second electrode may be directly fixed to the support or may be indirectly fixed.

  In the second embodiment, the sensor main body 112 (support 114) has a cylindrical shape, and the conductive rubber member 115 is disposed at one end (distal end) of the sensor main body 112 in the axial direction 30A. The conductive rubber member 115 only needs to be disposed at one end of the support 114 in the axial direction 30A. Therefore, the shape of the support body 114 is not limited to the cylindrical shape as long as it extends along the axial center line 30L of the guide wire 30, and may be, for example, a cylindrical shape or a prismatic shape. When the shape of the support body 114 is a columnar shape or a prism shape, and the support body 114 does not have an internal space, both the first electrode 121 and the second electrode 122 are fixed on the outer surface of the support body 114, for example. The The conductive rubber member 115 may be disposed at the proximal end of the support 114 as long as it is one end of the support 114.

  In the third embodiment, the sensor main body 212 (support 214) has a cylindrical shape, and the conductive rubber member 215 is disposed outside the sensor main body 212 in the radial direction 30R. The shape of the support 214 is not limited to a cylindrical shape as long as it extends along the axis 30L of the guide wire 30, and may be, for example, a cylindrical shape or a prismatic shape. When the shape of the support 214 is a columnar shape or a prism shape and the support 214 does not have an internal space, both the first electrode 221 and the second electrode 222 are fixed on the outer surface of the support 214, for example. The

  In the third embodiment, the cylindrical conductive rubber member 215 is provided at one location of the cylindrical sensor body 212 (support 214). A plurality of conductive rubber members 215 may be provided at different positions of the sensor main body 212 (support 214) along the axial direction 30A. In the third embodiment, the through hole 213 is provided to electrically connect the conductive rubber member 215 to the first electrode 221 disposed in the internal space (axial space 216) of the support 214. . Therefore, a plurality of through holes 213 may be formed on the side wall of the support body 214 along the axial direction 30 </ b> A corresponding to the plurality of conductive rubber members 215. A plurality of through holes 213 may be provided along the circumferential direction 30 </ b> C with respect to one cylindrical conductive rubber member 215. Further, the shape of the conductive rubber member 215 is not limited to the cylindrical shape surrounding the support 214. The length of the conductive rubber member 215 in the circumferential direction 30 </ b> C may be a multiple of the outer peripheral length of the support 214. In this case, the plurality of conductive rubber members 215 may be arranged along the circumferential direction 30 </ b> C of the support body 214. Correspondingly, the plurality of through holes 213 may be arranged along the circumferential direction 30 </ b> C of the support body 214.

10, 110, 210 ... Pressure measuring devices 11, 111, 211 ... Pressure sensors 13, 113 ... Recesses 14, 114, 214 ... Supports 15, 115, 215 ... Conductive rubber member 21 , 121, 221... First electrode 22, 122, 222... Second electrode 30... Guide wire 30A... Axial direction 30R. 112S ... internal space 213 (of support) ... through hole (concave)

Claims (7)

A guide wire that is flexible and can be inserted into the lumen of a living body;
A support provided on the guide wire, having a recess;
A conductive rubber member fixed to the support, covering at least a part of the opening of the recess, and elastically deforming to change an electric resistance value;
A pressure measuring device comprising: a first electrode and a second electrode fixed to the support and electrically connected to the conductive rubber member. The support has a cylindrical shape and has an internal space, and the axial direction of the cylindrical shape is parallel to the axial direction of the guide wire,
The concave portion is a part of the internal space and opens in the axial direction,
The pressure measuring device according to claim 1, wherein the conductive rubber member is disposed at one end of the support in the axial direction. The first electrode is electrically connected to the conductive rubber member through the internal space of the support,
The pressure measuring apparatus according to claim 2, wherein the second electrode is provided on a side wall of the support and is electrically connected to the conductive rubber member. The support has a cylindrical shape having a through hole in a side wall, and the axial direction of the cylindrical shape is parallel to the axial direction of the guide wire,
The recess is the through hole,
The pressure measuring apparatus according to claim 1, wherein the conductive rubber member is provided outside in a radial direction of the support. The first electrode is electrically connected to the conductive rubber member through the through hole of the support,
The pressure measuring apparatus according to claim 4, wherein the second electrode is provided on a side wall of the support and is electrically connected to the conductive rubber member.   The pressure measuring apparatus according to claim 1, wherein the support includes a flat plate-shaped substrate. The guide wire has an internal space and a through hole that communicates the internal space and the outside.
The pressure measuring device according to any one of claims 1 to 6, wherein the conductive rubber member is disposed in an internal space of the guide wire.

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