Patent Publication Number: US-2019183356-A1

Title: Pressure Measurement Device, Guide Wire Connector, Guide Wire, and Method for Manufacturing Guide Wire

Description:
TECHNICAL FIELD 
     The present invention relates to a pressure measurement device which is inserted into a lumen of a living body to measure the pressure of a fluid in the lumen. The present invention also relates to a guide wire connector with a sensor to be inserted into a blood vessel. The present invention also relates to a guide wire to be inserted into a blood vessel and a method for manufacturing a guide wire. 
     BACKGROUND ART 
     As a method for measuring the pressure of a fluid in a lumen of a living body, e.g., blood pressure in coronary arteries, a method including inserting a guide wire having a pressure sensor into a blood vessel is known. Patent Document 1 discloses a guide wire with a sensor in which a pressure detecting sensor chip is disposed inside a housing provided in a tip portion of the guide wire. 
     The above-described sensor chip is provided with a diaphragm containing a wafer and a piezoelectric resistance element provided in the diaphragm. To the diaphragm of the guide wire inserted into a blood vessel, blood pressure is applied. When the diaphragm is deflected by the blood pressure, the electrical resistance value of the piezoelectric resistance element varies. By the application of a current to the piezoelectric resistance element, the amount of a current flowing through the piezoelectric resistance element varies according to the blood pressure. The blood pressure is calculated based on the variation in the current amount. 
     In order to detect various kinds of physical quantities in a blood vessel, for example, blood pressure and blood temperature, a guide wire having a sensor is inserted into the blood vessel. The guide wire is inserted into a vein from a lower portion of the collarbone or the thigh, and is sent out so as to reach coronary arteries, for example. 
     In order to calculate the physical quantities, such as blood pressure and blood temperature, in a calculation device based on data obtained by the sensor, the guide wire is electrically communicatively connected to the calculation device through a connector. On the end of the guide wire, a contact is provided and the connector is provided with terminals. The shape of the contact is generally a cylindrical shape. In a connector described in Patent Document 2, terminals are a pair of plate springs disposed facing each other. In a state where the guide wire is inserted into the connector, the contact of the cylindrical shape is held between the pair of plate springs. Thus, the contact of the guide wire is electrically connected to the terminals of the connector. 
     In order to detect various kinds of physical quantities in a blood vessel, e.g., blood pressure and blood temperature, a guide wire having a sensor is inserted into a blood vessel. The guide wire is inserted into a vein from a lower portion of the collarbone or the thigh, and then the tip thereof is sent to coronary arteries, for example. Then, the blood pressure in the coronary arteries is measured by the sensor provided on the tip of the guide wire. 
     Based on an electric signal output from the sensor, the physical quantities, such as blood pressure and blood temperature, are calculated in the calculation device. Therefore, the guide wire is connected to the calculation device so as to be able to communicate the electric signal through a female type connector and a cable. Power is supplied to the sensor from the calculation device. A male type connector which can be inserted into the female type connector is provided at the proximal end of the guide wire. The male type connector is provided with a plurality of electrodes, for example. The electrodes and the sensor are connected by conductive wires which are inserted into and passed through the internal space of the guide wire (see Patent Document 3). In each of the conductive wires, the electric signal output from the sensor is transmitted or power is supplied to the sensor. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2010-540114 
     Patent Document 2: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2001-516938 
     Patent Document 3: Japanese Unexamined Patent Application Publication No. 2003-225312 
     SUMMARY OF INVENTION 
     Technical Problem 
     In order to increase the blood pressure measurement accuracy, the gain (input/output ratio of voltage or current) of the sensor is desirably large. On the other hand, it is not desirable to increase the size of the sensor for an increase of the gain. 
     When the guide wire is moved forward and backward within a blood vessel, the guide wire is rotated. By rotating the guide wire, the tip of the guide wire which is configured to be easy to curve rotates. The direction of the tip of the curved guide wire is changed around the axis of the guide wire. This makes it easy to advance the tip of the guide wire into a target blood vessel in a branch portion of a blood vessel, for example. 
     In the connector described in Patent Document 2, the terminals are the pair of plate springs disposed facing each other as described above. The guide wire held by the pair of plate springs can move in the radial direction with respect to the central axis of the guide wire while rotating with the rotation of the guide wire. 
     In a direction where the pair of plate springs faces each other, even when the guide wire moves, the pair of plate springs moves following the movement of the guide wire. However, in a direction orthogonal to the direction where the pair of plate springs faces each other, the pair of plate springs does not follow the movement of the guide wire. Therefore, when the guide wire also moves in the direction orthogonal to the direction where the pair of plate springs faces each other, the electrical connection between the contact and the terminal is momentarily cut or a contact portion between the contact and the terminal shifts. As a result, a jump or a drift may arise in the electric signal transmitted to the calculation device from a sensor. 
     In general, the outer diameter of the guide wire is sufficiently smaller than 1 mm, and therefore the inner diameter of the internal space of the guide wire which the conductive wire is inserted into and passed through is similarly small. On the other hand, it is desirable that the conductive wires are not exposed to the outside from the guide wire from the viewpoint of preventing the breakage of the conductive wires. Therefore, the conductive wires and the electrodes are connected in the internal space of the male type connector of the guide wire but the connection operation tends to be complicated. 
     The present invention has been made in view of the above-described circumstances. It is an object of the present invention to provide a pressure measurement device capable of achieving an increase of the gain of a sensor. 
     It is another object of the present invention to provide a guide wire connector in which the electrical connection between a contact and a terminal is hard to be cut. 
     It is still another object of the present invention to provide a guide wire in which a conductive wire inserted into and passed through the internal space of the guide wire and an electrode of a connector are easily electrical connected and a method for manufacturing the guide wire. 
     Solution to Problem 
     (1) A guide wire connector according to the present invention is provided with a holding portion holding a guide wire, a support portion supporting the holding portion rotatably around an axis line of the guide wire held by the holding portion, a terminal electrically connected to a contact of the guide wire held by the holding portion, and a guide portion rotatable around the axis line of the guide wire with respect to the support portion. The holding portion is provided with a body having an insertion hole for the guide wire and a holding piece extending along an axis line of the insertion hole from the body and capable of being elastically deformed inward in a radial direction with respect to the axis line. The guide portion has a guide surface guiding the holding piece inward in the radial direction. The holding portion is slid along the axis line of the insertion hole with respect to the guide portion, whereby the holding piece abuts on the guide surface to be elastically deformed inward in the radial direction. 
     According to the above-described configuration, the holding portion is slid along the axis line of the insertion hole with respect to the guide portion, whereby the holding piece abuts on the guide surface to be elastically deformed inward in the radial direction. As a result, the guide wire is held by the holding piece. When slid in the opposite direction, the holding piece is separated from the guide surface, so that the hold of the guide wire is released. Therefore, the guide wire is held or the hold is released by sliding the holding portion. 
     (2) Preferably, the support portion is provided with a lock portion locking the slide of the holding portion at a position where the holding piece abuts on the guide surface and enabling the holding piece to rotate around the axis line of the guide wire, the holding portion is provided with a hook portion integrally molded with the body and capable of being elastically deformed inward in the radial direction, recessed portion is formed in a proximal end portion of the hook portion, and the recessed portion can be engaged with the lock portion. 
     According to the above-described configuration, the recessed portion is engaged with the lock portion of the support portion, whereby the relative movement of a holding component along the axis line with respect to the connector body is regulated. 
     (3) Preferably, the holding portion is provided with a fitting portion abutting on the guide portion to be fitted thereto at the position where the holding piece abuts on the guide surface and the guide portion is provided with a fitting target portion to be fitted to the fitting portion. 
     According to the above-described configuration, when the holding piece abuts on the guide surface, the fitting portion is fitted to a fitting target portion to abut thereon even in a state where the lock portion is not engaged with the recessed portions, so that the movement of the holding component to the proximal side of a support component. 
     (4) Preferably, the terminal has at least three terminal portions disposed around the axis line of the guide wire held by the holding portion and the three terminal portions individually abut on the contact while being elastically displaced outward in a radial direction of the guide wire held by the holding portion. 
     (5) Preferably, an angle θ around the axis line of the guide wire between two adjacent terminal portions satisfies a relationship of 90°&lt;θ&lt;180°. 
     According to the above-described configuration, with respect to the angle θ around the axis line of the guide wire between the two adjacent terminal portions, the at least three terminal portions disposed around the axis line of the guide wire are provided. Therefore, even when the contact moves in the radial direction so that the axis line of the guide wire shifts, each of the terminal portions follows the movement of the contact by the elastic deformation of the terminal portions. Therefore, a trouble that the electrical connection between the contact and the terminal is momentarily cut is hard to occur. Preferably, the angle θ satisfies the relationship of 90°&lt;θ&lt;180°. 
     (6) More preferably, the angle θ satisfies the relationship of θ=120°. 
     According to the above-described configuration, the angle θ satisfies the relationship of θ=120°, and therefore the three terminal portions are disposed at equal intervals. Therefore, even when the guide wire moves in any direction of the radial directions, each of the terminal portions follows the contact. Therefore, the trouble that the electrical connection between the contact and the terminal is momentarily cut is more difficult to occur. 
     (7) Preferably, each of the terminal portions has a contact surface facing the contact of the guide wire and the contact surface has a cross section along the axis line of the guide wire held by the holding portion of a curved shape protruding inward in the radial direction of the guide wire. 
     According to the above-described configuration, each of the terminal portions point-contacts the contact along the axis line of the guide wire. Therefore, when the guide wire moves along the axis line, each of the terminal portions easily retreats in a direction of separating from the axis line. Therefore, the guide wire can be easily inserted into and removed from the connector. 
     (8) Preferably, each of terminal portions is a plate spring and the terminal has a shape in which each of both ends in a direction along the axis line of the guide wire in each of the plate springs integrally continues in a cylindrical shape along the circumferential direction. 
     (9) Preferably, the terminal is provided with a body in which one end in a direction along the axis line of the guide wire in each of the plate springs integrally continues in a cylindrical shape along the circumferential direction and a converging tube externally fitted to the other end of each of the plate springs and capable of being elastically deformed so as to enlarge the diameter. 
     According to the above-described configuration, the converging tube is externally fitted to the other end of each of the plate springs and capable of being elastically deformed so as to enlarge the diameter. The plate spring which is the terminal portion is subject to not only the energization force of the plate spring itself but the energization force caused by a tubular spring. Therefore, the energization force of the terminal portions is easily adjusted. 
     (10) A guide wire according to the present invention has a tubular body, a conductive wire which is inserted into and passed through the internal space of the body to be extended from a proximal end portion of the body, and a connector having a tubular shape and having an electrode ring exposed to the outer peripheral surface of the tubular shape and an electrode pin connected to the electrode ring and extended from a distal end portion through the internal space of the tubular shape to be connected to the conductive wire in the distal end portion. 
     According to the above-described configuration, a distal end portion of the electrode pin and the conductive wire are easily connected even when the electrode ring and the electrode pin are assemblies beforehand. 
     (11) Preferably, the guide wire has two or more of the conductive wires, two or more of the electrode rings located apart from each other in an axial direction, and two or more of the electrode pins connected to the two or more of the electrode rings, in which the conductive wires and the electrode pins are connected in one-to-one correspondence. 
     (12) Preferably, the electrode pins are disposed at different positions in the circumferential direction in the internal space of a connector. 
     The strength of the connector is held due to the fact that the electrode pins are bundled in the internal space of the electrode rings. 
     (13) Preferably, distal end portions of the electrode pins are disposed at different positions in the axial direction in the internal space of the connection tube. 
     According to the above-described configuration, the connection relationship between each of the electrode pins and each of the electrode rings can be grasped based on the positions of the distal end portions. 
     (14) Preferably, the electrode pins each have an insulation coated outer periphery and conduction portions not having the insulation coat at the distal end portion and a position corresponding to the electrode ring to be connected, in which the electrode pins are individually connected to the conductive wires and the electrode rings in the conduction portions and the conduction portions of the electrode pins do not overlap in the axial direction. 
     According to the above-described configuration, a short circuit between the conduction portions of the electrode pin can be suppressed. 
     (15) Preferably, the guide wire further has a connection tube covering the conductive wires and the electrode pins and connecting the proximal end portion of the body and the distal end portion of the connector. 
     The connection tube covering connection portions of the conductive wires and the electrode pins is configured as a separate body from the body and the connector. Therefore, there is no member covering the connection portions of the conductive wires and the electrode pins in a state where the connection tube is not connected to the body and the connector, and thus the workability is good. 
     (16) Preferably, the body has a tapered portion in which the outer diameter decreases toward the proximal end and a small-diameter portion extended from the tapered portion to the proximal end, in which the connection tube is movable in the axial direction with respect to the small-diameter portion in a state of being externally fitted to the small-diameter portion. 
     By the movement of the connection tube in the axial direction with respect to the small-diameter portion, the connection portions between the conductive wires and the electrode pins are exposed to the outside or covered. Moreover, due to the fact that the connection tube is externally fitted to the small-diameter portion, the outer diameter of the connection tube can be made small. 
     (17) Preferably, the connection tube contains a conductive material and is electrically connected to the body. 
     According to the above-described configuration, the body can be easily grounded through the connection tube. 
     (18) Preferably, the guide wire further has an electronic component which is located in a distal end portion of the body to be connected to the conductive wires and outputs an electric signal according to the physical quantity of a fluid. 
     (19) A method for manufacturing a guide wire according to the present invention includes a first process of electrically connecting a conductive wire inserted into and passed through the internal space of a tubular body to be extended from a proximal end portion of the body and an electrode pin connected to an electrode ring provided in a tubular connector and extended from a distal end portion through the internal space of the connector and a second process of connecting a connection tube to the proximal end portion of the body and the distal end portion of the connector while covering the conductive wire and the electrode pin. 
     According to the above description, in a state where the connection tube is not connected to the body and the connector, there is no member covering a connection portion of the conductive wire and the electrode pin, and thus the workability is good. 
     (20) Preferably, in the first process, the connection tube is brought into an externally fitted state of being externally fitted to the body or the connector, and then the conductive wire and the electrode pin are electrically connected and, in the second process, the connection tube in the externally fitted state is moved in a direction of projecting in an axial direction from the proximal end portion of the body or a direction of projecting in the axial direction from the distal end portion of the connector. 
     By the movement of the connection tube from the externally fitted state with respect to the body or the connector, the connection portion between the conductive wire and the electrode pin is exposed to the outside or covered 
     (21) A pressure measurement device according to the present invention is provided with a guide wire having flexibility and capable of being inserted into a lumen of a living body and a sensor provided in the guide wire, in which the guide wire has a cylindrical housing accommodating the sensor and the sensor has a sensor body having a distal end surface facing the distal side in an axial direction of the guide wire, a diaphragm disposed on the distal end surface, abridge circuit disposed on the distal end surface and surrounding the diaphragm, and four conductive wires connected to the bridge circuit. The bridge circuit is provided with four resistors which are fixed to an outer peripheral portion of the diaphragm and in which an electrical resistance value varies with elastic deformation of the diaphragm and four terminals connected to the four resistors and the four conductive wires. 
     According to the above-described configuration, the four resistors are fixed to the outer peripheral portion of the diaphragm. Therefore, when the diaphragm is elastically deformed by the pressure of a fluid in a lumen, the electrical resistance values of the four resistors individually vary. Therefore, the gain of the sensor increases. 
     (22) Preferably, space is formed on the distal side relative to the distal end surface of the sensor. 
     According to the above-described configuration, a vibration caused by the contact between a distal end portion of the guide wire and the wall surface in a lumen is difficult to be transmitted to the sensor, and therefore the detection accuracy of the sensor becomes high. Furthermore, due to the fact that a tip guide portion, a spiral body, and the like are provided on the distal side relative to the space, the contact with the wall surface in the lumen is further buffered and the vibration is difficult to be transmitted to the sensor, and therefore the detection accuracy of the sensor becomes higher. 
     (23) Preferably, the shape of the diaphragm is a disk shape. 
     According to the above-described configuration, the shape of the diaphragm is the disk shape. Therefore, when the diaphragm is elastically deformed, the deformation amount of an outer peripheral portion of the diaphragm is uniform irrespective of positions in the circumferential direction. The variation amount of the electrical resistance value of the resistor is proportional to the deformation amount of the diaphragm at the position where the resistor is fixed. Therefore, even when the position of the resistor with respect to the diaphragm somewhat shifts due to variations in manufacturing and the like, for example, the resistance variation characteristics of the resistors, i.e., the variation amount of the electrical resistance value to pressure variation, do not sharply fluctuate. In the four resistors, the resistance variation characteristics are kept uniform, and therefore a fluctuation of the gain of the sensor due to the variations in manufacturing is small. 
     (24) Each of the terminals is disposed between two adjacent resistors among the four resistors. 
     According to the above-described configuration, each terminal is disposed between the two adjacent resistors. Therefore, the path length of the bridge circuit is shortened as compared with a case where each terminal is disposed at a position deviated from the position between the two resistors. Thus, a small reduction of the sensor is achieved. 
     (25) The sensor body has a proximal end surface facing the proximal side in the axial direction, four through-holes opened to the distal end surface and the proximal end surface and formed along the axial direction, and four electroconductive layers individually laminated around an opening of each of the four through-holes of the distal end surface, in which the terminals are the electroconductive layers. 
     According to the above-described configuration, each of the conductive wires is connected to a portion laminated on the distal end surface of the sensor body of each electroconductive layer. Therefore, no conductive wires are disposed on the outer peripheral surface of the sensor body. 
     (26) Preferably, the sensor is provided with a coating member partially covering the four electroconductive layers and the four conductive wires and covering at least connection portions between the electroconductive layer and the conductive wires. 
     According to the above-described configuration, a fluid in a lumen does not contact the connection portion. Therefore, a degradation of the connection portion is suppressed and the connection portion is waterproofed and insulated. 
     (27) Preferably, the guide wire is provided with a core wire and a tapered pin fixed to a distal end portion of the core wire, in which the tapered pin is connected to the coating member. 
     Advantageous Effects of Invention 
     The pressure measurement device of the present invention can achieve an increase in the gain of the sensor. 
     Moreover, according to the present invention, a trouble that the electrical connection between the contact and the terminal is momentarily cut is difficult to occur. 
     Moreover, the present invention facilitates the electrical connection between the conductive wire inserted into and passed through the internal space of the guide wire and the electrode of the connector. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view of a pressure measurement device according to a first embodiment of the present invention. 
         FIG. 2  is an enlarged cross sectional view along the cut line II-II of  FIG. 1 . 
         FIG. 3  is an enlarged cross sectional view along the cue line III-III of  FIG. 1 . 
         FIG. 4  is a perspective view of a pressure sensor. 
         FIG. 5  illustrates cross-sectional views along the cut line V-V of  FIG. 4 . 
         FIG. 6  is a view as viewed from a direction indicated by the arrow VI of  FIG. 4 . 
         FIG. 7  is a circuit view of a bridge circuit according to the first embodiment of the present invention. 
         FIG. 8  is a schematic view of a guide wire system according to a second embodiment of the present invention. 
         FIG. 9  is a view illustrating a guide wire according to the second embodiment of the present invention. 
         FIG. 10  is a perspective view of a pressure sensor. 
         FIG. 11  is a perspective view of a connector according to the second embodiment of the present invention. 
         FIG. 12  is an exploded perspective view of the connector according to the second embodiment of the present invention. 
         FIG. 13  are cross-sectional views of the connector according to the second embodiment of the present invention in a non-lock state and particularly  FIG. 13(A)  is a cross-sectional view along the cut line VIA-VIA of  FIG. 4  and  FIG. 13(B)  is a cross-sectional view along the cut line VIB-VIB. 
         FIG. 14  are cross-sectional views of the connector according to the second embodiment of the present invention in a lock state and particularly  FIG. 14(A)  is a cross-sectional view along the cut line VIA-VIA of  FIG. 11  and  FIG. 14(B)  is a cross-sectional view along the cut line VIB-VIB. 
         FIG. 15  is a cross-sectional perspective view of a terminal case according to the second embodiment of the present invention along the cut line VIA-VIA of  FIG. 11 . 
         FIG. 16  is a perspective view of a terminal of the connector according to the second embodiment of the present invention. 
         FIG. 17  are views of the terminal of the connector according to the second embodiment of the present invention and particularly  FIG. 17(A)  is a front view,  FIG. 17(B)  is a top view,  FIG. 17(C)  is a side view, and  FIG. 17(D)  is a developed view. 
         FIG. 18  are cross-sectional view along the cut line XI-XI of  FIG. 16  and particularly  FIG. 18(A)  is a cross-sectional view of the terminal of the connector according to the second embodiment of the present invention and  FIG. 18(B)  and  FIG. 18(C)  are cross-sectional views of a contact between the terminal of the connector and a guide wire according to the second embodiment of the present invention. 
         FIG. 19  is a perspective view of a terminal of a connector according to a third embodiment of the present invention. 
         FIG. 20  is a front view of the terminal of the connector according to the third embodiment of the present invention. 
         FIG. 21  illustrates contact stability data of Amplifier input (V)-Time (S) according to the second embodiment of the present invention. 
         FIG. 22  illustrates contact stability data of Amplifier input (V)-Time (S) about Combowire of Volcano as a comparative article. 
         FIG. 23  illustrates contact stability data of Amplifier input (V)-Time (S) about Certus of St Jude Medical as a comparative article. 
         FIG. 24  is a schematic view of a guide wire system  310 . 
         FIG. 25  is a view illustrating a guide wire  330 . 
         FIG. 26  is a perspective view of a pressure sensor  311 . 
         FIG. 27  is an exploded view of a male type connector  339 . 
         FIG. 28  is a view illustrating each of the electrode pins  345 . 
         FIG. 29  is a cross-sectional view along the cut line VI-VI of  FIG. 27 . 
         FIG. 30  is a view illustrating the guide wire  330  when a connection tube  336  is in an externally fitted state. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, preferable embodiments of the present invention are described. It is a matter of course that the embodiments are merely exemplary of the present invention and the embodiments can be altered in the range where the gist of the present invention is not altered. 
     [Configuration of First Embodiment] 
     &lt;Pressure Measuring Device  10 &gt; 
     As illustrated in  FIG. 1 , a pressure measurement device  10  according to a first embodiment is provided with a guide wire  30  and a pressure sensor  11  provided in the guide wire  30 . To one end of the guide wire  30 , a calculation control portion  40  is electrically connected. In  FIG. 1 , a fixed end (end connected to the calculation control portion  40 ) is a proximal end (right side in  FIG. 1 ) of both ends of the guide wire  30  and a free end (tip when inserted into a blood vessel) thereof is a distal end (left side in  FIG. 1 ). Hereinafter, in the guide wire  30 , the side where the proximal end is present is defined as a proximal side and the side where the distal end is present is defined as a distal side. 
     The guide wire  30  is a long and narrow cable and can be inserted into blood vessels (example of the lumen of a living body), such as coronary arteries. The pressure sensor  11  is provided in an end portion on the distal side of the guide wire  30 . The calculation control portion  40  calculates the blood pressure (example of the pressure of the fluid in a lumen) based on electric information (voltage value) to be output from the pressure sensor  11 . More specifically, the pressure measurement device  10  is used for the measurement of the blood pressure. 
       FIG. 1  to  FIG. 3  illustrate an axial center line  30 L of the guide wire  30 . In this specification, directions relating to components configuring the guide wire  30 , i.e., an axial direction  30 A, a radial direction  30 R, and a circumferential direction  30 C, are defined as follows. The axial direction  30 A, the radial direction  30 R, and the circumferential direction  30 C are defined based on the axial center line  30 L in a state where the guide wire  30  is in a straight state without being deflected or curved, i.e., the axial center line  30 L which is a straight line. The axial direction  30 A is a direction parallel to the axial center line  30 L and including both the distal direction and the proximal direction. The radial direction  30 R includes all directions orthogonal to the axial center line  30 L. The circumferential direction  30 C is a direction around the axial center line  30 L. 
     &lt;Guide Wire  30 &gt; 
     As illustrated in  FIG. 1 , the guide wire  30  is provided with a core wire  31 , a tip guide portion  32 , a first spiral body  33 , a housing  34 , a second spiral body  35 , and a guide tube  38 . As illustrated in  FIG. 2 , the guide wire  30  is provided with a tapered pin  39 . As illustrated in  FIG. 3 , the guide wire  30  is provided with a connection wall  36  and a tip wire  37 . 
     As illustrated in  FIG. 1 , the core wire  31  is a member configuring the skeleton of the guide wire  30 . The core wire  31  gives fixed mechanical strength to the curving of the guide wire  30  so that the guide wire  30  can be inserted into a blood vessel without being crooked. The core wire  31  is a cylindrical wire rod and extends from the proximal end to the distal side. The material of the core wire  31  is medical stainless steel, for example. The axial center line of the core wire  31  is parallel to the axial center line  30 L. 
     In the core wire  31 , the distal side is easier to deflect than the proximal side. The core wire  31  has a small-diameter portion  31   a  located on the distal side, a large-diameter portion  31   b  located on the proximal side, and a tapered portion  31   c  connecting the small-diameter portion  31   a  and the large-diameter portion  31   b . The small-diameter portion  31   a  and the large-diameter portion  31   b  each have a fixed outer diameter. The outer diameter of the large-diameter portion  31   b  is larger than the outer diameter of the small-diameter portion  31   a . The outer diameter of the tapered portion  31   c  is equal to the outer diameter of the large-diameter portion  31   b  in the proximal end, gradually decreases toward the distal end from the proximal end, and is equal to the outer diameter of the small-diameter portion  31   a  in the distal end. Due to the fact that the outer diameter of the core wire  31  gradually decreases toward the distal side, the rigidity of the core wire  31  decreases in order of the large-diameter portion  31   b , the tapered portion  31   c , and the small-diameter portion  31   a.    
     As illustrated in  FIG. 2 , the tapered pin  39  is disposed from a distal end portion of the core wire  31  on the distal side. The tapered pin  39  is also a member configuring the skeleton of the guide wire  30  as with the core wire  31  and gives fixed mechanical strength to the curving of the guide wire  30 . 
     The tapered pin  39  is provided with a shaft portion  39   a  located on the proximal side and a tapered portion  39   b  extending from the shaft portion  39   a  to the distal side. The outer diameter of the shaft portion  39   a  is constant. The shaft portion  39   a  is inserted into the small-diameter portion  31   a  of the core wire  31 . The shaft portion  39   a  is fixed to the small-diameter portion  31   a  by laser welding or an adhesive, for example. The outer diameter of the tapered portion  39   b  is formed to be tapered toward the distal side. Therefore, the rigidity of the tapered portion  39   b  gradually decreases toward the distal side. A distal end portion of the guide wire  30  where the tapered pin  39  is disposed is easy to bend, and therefore the guide wire  30  is easily guided along a blood vessel. Moreover, a slot  39   c  opened to the outer peripheral surface of the tapered pin  39  is formed in parallel to the axial direction  30 A from the proximal end of the tapered pin  39  to a proximal side portion of the tapered portion  39   b . Four conductive wires  15  (described later) of the pressure sensor  11  pass through the inside of the core wire  31  via the slot  39   c  to be connected to the calculation control portion  40 . 
     As illustrated in  FIG. 1  and  FIG. 2 , the guide tube  38  is located on the outside in the radial direction  30 R of the small-diameter portion  31   a  of the core wire  31  and covers a proximal side portion of the small-diameter portion  31   a . The shape of the guide tube  38  is a cylindrical shape. The axial center line of the guide tube  38  is parallel to the axial center line  30 L. 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  contains medical synthetic resin, for example, and is thermally fused to the outer peripheral surface of the core wire  31 , for example. 
     As illustrated in  FIG. 1  and  FIG. 3 , the tip guide portion  32  is disposed at the distal end of the guide wire  30 . The tip guide portion  32  is a portion abutting on a blood vessel wall when the guide wire  30  is inserted into a blood vessel to thereby guide the movement direction of the guide wire  30  along the blood vessel. The tip guide portion  32  is provided with a hemispherical portion  32   a  located on the distal side and a columnar portion  32   b  extending from the hemispherical portion  32   a  to the proximal side. The hemispherical portion  32   a  has a hemispherical shape projecting to the distal side so as not to damage the blood vessel wall. The outer diameter of the hemispherical portion  32   a  is almost equivalent to the outer diameter of the second spiral body  35 . The columnar portion  32   b  has a cylindrical shape projecting from the hemispherical portion  32   a  to the proximal side and having an outer diameter smaller than the outer diameter of the hemispherical portion  32   a . The columnar portion  32   b  is inserted into the second spiral body  35 , whereby the tip guide portion  32  is positioned with respect to the second spiral body  35 , so that the outer surfaces of the hemispherical portion  32   a  and the second spiral body  35  smoothly continue without a level difference. The material of the tip guide portion  32  is medical stainless steel, for example. 
     As illustrated in  FIG. 1  and  FIG. 3 , the first spiral body  33  and the second spiral body  35  are provided on the distal side of the guide wire  30 . The first spiral body  33  and the second spiral body  35  have bending rigidity lower than that of the tapered pin  39 , i.e., easy to bend. The first spiral body  33  is configured by a spirally wound wire rod. The material of the first spiral body  33  is medical stainless steel, for example. The axial center line of the first spiral body  33  is parallel to the axial center line  30 L. As illustrated in  FIG. 2 , the tapered portion  39   b  of the tapered pin  39  is inserted into the first spiral body  33 . The first spiral body  33  has a proximal end portion  33   a  ( FIG. 2 ) and a distal end portion  33   b  ( FIG. 3 ). As illustrated in  FIG. 2 , the proximal end portion  33   a  is fixed to the outer peripheral surface of the tapered portion  39   b  of the tapered pin  39  by laser welding or an adhesive, for example. Thus, the bending rigidity of the first spiral body  33  is reinforced with the tapered pin  39 . 
     As illustrated in  FIG. 1  and  FIG. 3 , the housing  34  is a casing accommodating the pressure sensor  11  in an internal space  34 S thereof. The housing  34  has a cylindrical shape and has the internal space  34 S. The material of the housing  34  is medical stainless steel, for example. The axial center line of the housing  34  is parallel to the axial centerline  30 L. In a proximal end portion of the housing  34 , the distal end portion  33   b  of the first spiral body  33  is fixed by laser welding or an adhesive, for example. 
     The housing  34  has a plurality of through-holes  34   a . In the first embodiment, the housing  34  has two through-holes  34   a . The through-holes  34   a  penetrate a cylindrical wall of the housing  34  along the radial direction  30 R. The internal space  34 S of the housing  34  and the outside communicate with each other through the through-holes  34   a . The two through-holes  34   a  are disposed along the circumferential direction  30 C of the guide wire  30  at a 180° interval around the axial center line  30 L. 
     The second spiral body  35  is configured by a spirally wound wire rod. The material of the second spiral body  35  is medical stainless steel, for example. The axial center line of the second spiral body  35  is parallel to the axial center line  30 L. The second spiral body  35  has a proximal end portion  35   a  and a distal end portion  35   b . The proximal end portion  35   a  of the second spiral body  35  is fixed to a distal end portion of the housing  34 . The second spiral body  35  and the housing  34  are fixed by laser welding or an adhesive, for example. The columnar 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  35   b  is fixed to the outer peripheral surface of the columnar portion  32   b . The second spiral body  35  and the tip guide portion  32  are fixed by laser welding or an adhesive, for example. 
     The connection wall  36  is a member for connecting the tip wire  37  to the housing  34 . The connection wall  36  is fixed to the distal end portion of the housing  34 . The connection wall  36  is configured by a metal soldering material, for example. 
     The tip wire  37  reinforces the bending rigidity of the second spiral body  35 . The tip wire  37  is a wire rod containing medical stainless steel, for example. The axial center line of the tip wire  37  is parallel to the axial center line  30 L. A proximal end portion of the tip wire  37  is fixed to the connection wall  36 . A distal end portion of the tip wire  37  is fixed to the columnar portion  32   b  of the tip guide portion  32  by laser welding or an adhesive, for example. 
     According to the configuration described above, the tapered pin  39  and the tip guide portion  32  are connected through 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 through the tip wire  37 . The tapered pin  39  is fixed to the core wire  31 . Thus, the guide wire (except the core wire  31 )  30  itself is supported by the core wire  31  and mechanical strength is given thereto. 
     According to such a configuration, when an operation of sending out the guide wire  30  to a blood vessel in the proximal end is performed, the guide wire  30  progresses in the blood vessel without being crooked following the operation. When the tip guide portion  32  contacts the blood vessel wall, the guide wire  30  is curved along the blood vessel wall. 
     &lt;Pressure Sensor  11 &gt; 
     As illustrated in  FIG. 3 , the pressure sensor  11  is disposed in the internal space  34 S of the housing  34 . A proximal side portion of the internal space  34 S is almost filled with the pressure sensor  11 . On the other hand, the internal space  34 S located on the distal side of the internal space  34 S, i.e., on a distal side of the pressure sensor  11 , is present as the space. The through-holes  34   a  of the housing  34  are opened in the distal side portion of the internal space  34 S. 
     As illustrated in  FIG. 3  to  FIG. 6 , the pressure sensor  11  is provided with a sensor body  12 , a diaphragm  13 , a bridge circuit  14 , four conductive wires  15 , and a coating member  16 . 
     As illustrated in  FIG. 4 , the shape of the sensor body  12  is a cylindrical shape. To the sensor body  12 , the diaphragm  13 , the bridge circuit  14 , and the four conductive wires  15  are attached. The axial center line of the sensor body  12  is parallel to the axial center line  30 L. The sensor body  12  has a distal end surface  12   a  facing the distal side, a proximal end surface  12   b  facing the proximal side, and an outer peripheral surface  12   c  facing the radial direction  30 R. 
     As illustrated in  FIG. 5 , the sensor body  12  has a recessed portion  21 . The recessed portion  21  is provided in the sensor body  12  so as to enable the diaphragm  13  to be easily deformed by the pressure of a fluid in a lumen. The recessed portion  21  is opened to the distal end surface  12   a . The shape of the recessed portion  21  is a circular shape as viewed from the distal side of the sensor body  12 . The depth of the recessed portion  21  in the axial direction  30 A is constant. The axial center line of the recessed portion  21  is in agreement with the axial center line of the sensor body  12 . 
     As illustrated in  FIG. 4  to  FIG. 6 , the sensor body  12  has four through-holes  22 . The four through-holes  22  are formed in the sensor body  12  in order to provide four terminals  18  described later in the sensor body  12 . The four through-holes  22  are disposed along the circumferential direction  30 C at 90° intervals around the axial center line of the sensor body  12 . Each through-hole  22  extends along the axial direction  30 A and is opened to both the distal end surface  12   a  and the proximal end surface  12   b  of the sensor body  12 . The shape of the through-hole  22  is a circular shape as viewed from the axial direction  30 A. 
     As illustrated in  FIG. 4  to  FIG. 6 , the diaphragm  13  is disposed on and fixed onto the distal end surface  12   a  of the sensor body  12 . The shape of the diaphragm  13  is a disk shape. More specifically, the shape of the diaphragm  13  is a circular shape as viewed from the axial direction  30 A and is a rectangular shape as viewed from the radial direction  30 R. The axial center line of the diaphragm  13  and the axial center line of the sensor body  12  are in agreement with each other. The distal end surface  12   a , the diaphragm  13 , and the recessed portion  21  are coaxially disposed. The outer diameter of the diaphragm  13  is larger than the diameter of the inner peripheral surface of the recessed portion  21 . The diaphragm  13  covers the entire opening of the recessed portion  21 . 
     As illustrated in  FIG. 4 ,  FIG. 6 , and  FIG. 7 , the bridge circuit  14  is provided with four resistors  17  ( 17 A,  17 B), four terminals  18  ( 18 A,  18 B,  18 C,  18 D), and four connection bodies  19 . The bridge circuit  14  surrounds the diaphragm  13 . 
     The bridge circuit  14  is a full bridge circuit in which the four resistors  17  all function as a distortion gauge for measurement. Therefore, the four resistors  17  contain two kinds of resistors different in the resistance variation characteristic. The two kinds of resistors are a first resistor  17 A and a second resistor  17 B. In this specification, when the first resistors  17 A and the second resistors  17 B do not need to be distinguished from each other, the first resistors  17 A and the second resistors  17 B are referred to as the resistors  17 . 
     The four resistors  17  are fixed to the surface on the distal side of the diaphragm  13 . The four resistors  17  are fixed to an outer peripheral portion of the diaphragm  13  as viewed from the axial direction  30 A. The four resistors  17  are disposed along the circumferential direction  30 C at 90° intervals around the axial center line of the sensor body  12 . Herein, the first resistors  17 A and the second resistors  17 B are alternately arranged along the circumferential direction  30 C. 
     Both the first resistors  17 A and the second resistors  17 B are semiconductors utilizing a piezoelectric resistance effect. The resistors  17  are fixed to the diaphragm  13 , and therefore elastically deformed with the elastic deformation of the diaphragm  13 . When the resistor  17  is elastically deformed, electrical resistance values of the resistor  17  vary. 
     The shapes of the first resistors  17 A and the second resistors  17 B are different from each other. The attitudes of the first resistors  17 A and the second resistors  17 B to the diaphragm  13  are also different from each other. Due to the differences in the shape and the attitude, the difference in the resistance variation characteristic described above is brought about between the first resistor  17 A and the second resistor  17 B. 
     The shape of the first resistor  17 A is a square U-shape as viewed from the axial direction  30 A. The first resistor  17 A is provided with a circumferential direction component  51  and two radial direction components  52  in the attitude to the diaphragm  13 . The circumferential direction component  51  extends substantially along the circumferential direction of the diaphragm  13 . The radial direction components  52  extend substantially along the radial direction of the diaphragm  13 . The first resistors  17 A are configured so that the electrical resistance value increases with the deformation of the diaphragm  13  in pressurization. 
     The shape of the second resistor  17 B is a rectangular shape as viewed from the axial direction  30 A. The second resistor  17 B is configured by a circumferential direction component extending substantially along the circumferential direction of the diaphragm  13  in the attitude to the diaphragm  13 . The second resistor  17 B is configured so that the electrical resistance value decreases with the deformation of the diaphragm  13  in pressurization. 
     As illustrated in  FIG. 6  and  FIG. 7 , the four terminals  18  are two input terminals  18 A and  18 C and two output terminals  18 B and  18 D in the bridge circuit  14 . In this specification, when the input terminals  18 A and  18 C and the two output terminals  18 B and  18 D do not need to be distinguished from each other, the input terminals  18 A and  18 C and the two output terminals  18 B and  18 D are referred to as the terminals  18 . As illustrated in  FIG. 5 , the four terminals  18  are four electroconductive layers individually provided corresponding to the four through-holes  22  of the sensor body  12 . The electroconductive layer contains a distal electroconductive layer  24  laminated around an opening of each through-hole  22  in the distal end surface  12   a.    
     As illustrated in  FIG. 4  and  FIG. 6 , the four terminals  18  are disposed on the outside of the diaphragm  13  in the radial direction  30 R. The four terminals  18  are disposed along the circumferential direction  30 C at 90° intervals around the axial center line of the sensor body  12 . The four terminals  18  and the four resistors  17  are alternately arranged in the circumferential direction  30 C. Each terminal  18  is disposed between the two adjacent resistors  17  among the four resistors  17 . 
     As illustrated in  FIG. 4  to  FIG. 6 , the four connection bodies  19  are individually provided corresponding to the four terminals  18 . Each connection body  19  is the electroconductive layer laminated around the opening of each through-hole  22  in the distal end surface  12   a . Each connection body  19  electrically connects the two adjacent resistors  17  and the terminal  18  located between the two adjacent resistors  17 . Thus, the four resistors  17  and the four terminals  18  are alternately electrically connected. 
     As illustrated in  FIG. 6 , in the bridge circuit  14 , the two input terminals  18 A and  18 C are disposed at a 180° interval from each other and the two output terminals  18 B and  18 D are disposed at a 180° interval from each other. As illustrated in  FIG. 6  and  FIG. 7 , the bridge circuit  14  has two paths, one path  27  and the other path  28 , from one input terminal  18 A toward the other input terminal  18 C. The one path  27  is a path passing through the first resistor  17 A, one output terminal  18 B, and the second resistor  17 B. The other path  28  is a path passing through the second resistor  17 B, the other output terminal  18 D, and the first resistor  17 A. Herein, the one input terminal  18 A is a high-pressure side and the other input terminal  18 C is a low-pressure side. 
     In a state where a voltage is applied between the two input terminals  18 A and  18 C, a voltage drop occurs in order of the first resistor  17 A and the second resistor  17 B in the one path  27  and a voltage drop occurs in order of the second resistor  17 B and the first resistor  17 A in the other path  28 . 
     In a state where the diaphragm  13  is not pressurized, the first resistors  17 A and the second resistors  17 B are not deformed. At this time, the electrical resistance values of the first resistor  17 A and the second resistor  17 B are the same. Therefore, a potential difference is not generated between the two output terminals  18 B and  18 D. 
     On the other hand, in a state where the diaphragm  13  is pressurized, the first resistors  17 A and the second resistors  17 B are deformed. As described above, the electrical resistance value of the first resistors  17 A increases and the electrical resistance value of the second resistors  17 B decreases in pressurization. More specifically, the voltage drop amount in the first resistors  17 A is larger than the voltage drop amount in the second resistors  17 B. Therefore, a potential difference is generated between the two output terminals  18 B and  18 D. 
     In a state where the guide wire  30  is inserted into a blood vessel, so that blood pressure is applied to the pressure sensor  11 , a potential difference is generated between the two output terminals  18 B and  18 D according to the blood pressure. The magnitude of the blood pressure can be specified based on the potential difference. 
     As illustrated in  FIG. 5 , the four conductive wires  15  are individually electrically connected to the four terminals  18 . The terminal  18  has the distal electroconductive layer  24  laminated on the distal end surface  12   a  as described above. To the distal electroconductive layer  24 , the conductive wire  15  is connected. The conductive wire  15  has a conductive wire body  15   a  containing a conductor and an insulation cover  15   b  containing an insulator. The insulation cover  15   b  covers the conductive wire body  15   a  except both end portions of the conductive wire body  15   a . In a distal end portion of the conductive wire  15 , the conductive wire body  15   a  is electrically and mechanically connected to the distal electroconductive layer  24  by soldering. By the solder, the connection portion  26  is formed between the conductive wire body  15   a  and the distal electroconductive layer  24 . 
     As illustrated in  FIG. 3  to  FIG. 5 , the coating member  16  is provided on the proximal side of the sensor body  12 . The coating member  16  contains an adhesive in the first embodiment. The coating member  16  is fixed to the proximal end surface  12   b  of the sensor body  12  and projects from the proximal end surface  12   b  to the proximal side. The coating member  16  partially proceeds into the four through-holes  22  of the sensor body  12  to close the openings of the four through-holes  22  in the proximal end surface  12   b . Distal side end portions of the four conductive wires  15  and the four connection portions  26  are covered with the coating member  16  and fixed to the coating member  16 . Herein, the entire conductive wire bodies  15   a  exposed from the insulation covers  15   b  are covered with the coating member  16 . 
     As illustrated in  FIG. 4  and  FIG. 6 , the four conductive wire bodies  15   a  and the four connection portions  26  are covered with the coating member  16  and fixed to the coating member  16  but the coating member  16  is omitted in  FIG. 4  and  FIG. 6  for explanation. The configuration of the coating member  16  is not limited to an adhesive and may be a solder, a solder paste, or the like. 
     As illustrated in  FIG. 4 , the tapered pin  39  is connected to the coating member  16  and fixed to the tapered pin  39 . Thus, the sensor body  12  is fixed to the tapered pin  39 . 
     &lt;Calculation Control Portion  40 &gt; 
     As illustrated in  FIG. 1 , the calculation control portion  40  has the four conductive wires  15  electrically connected to the pressure sensor  11 , a power supply portion  41  supplying a current to the pressure sensor  11 , a calculation portion  42  performs calculation processing of electric information to be output from the pressure sensor  11 , and a connector  43  connected to the four conductive wires  15 . 
     As illustrated in  FIG. 1 , the power supply portion  41  is configured so as to apply a voltage to the bridge circuit  14  of the pressure sensor  11  through the two conductive wires  15  connected to the two input terminals  18 A and  18 C. 
     The calculation portion  42  acquires a voltage value to be output from the bridge circuit  14  of the pressure sensor  11  through the two conductive wires  15  connected to the two output terminals  18 B and  18 D. The calculation portion  42  calculates the blood pressure acting on the pressure sensor  11  based on a variation in the acquired output voltage value. The calculation portion  42  is provided with a memory  42   a . More specifically, the calculation portion  42  calculates the blood pressure as follows. 
     The memory  42   a  stores the correspondence relationship between the output voltage value and the blood pressure as described above as data in one to one correspondence, for example. Therefore, when the output voltage value is acquired, the calculation portion  42  can specify the blood pressure corresponding to the output voltage value based on the correspondence relationship stored in the memory  42   a . Thus, the calculation portion  42  can calculate the blood pressure acting on the pressure sensor  11  based on the voltage value to be output from the pressure sensor  11 . 
     &lt;Use Example of Pressure Measurement Device  10 &gt; 
     The pressure measurement device  10  is used in order to measure the blood pressure in coronary arteries, for example. The guide wire  30  is inserted into the coronary arteries with the distal end where the tip guide portion  32  is provided as the head in the insertion direction into a blood vessel. The position of the guide wire  30  in the coronary arteries is grasped based on the position of the tip guide portion  32  projected on an X-ray fluoroscopic image of the blood vessel. 
     When the pressure sensor  11  reaches the measurement position of the blood pressure in the coronary arteries, the insertion of the guide wire  30  is interrupted. In such a state, a fixed voltage is supplied to the pressure sensor  11  from the power supply portion  41  by an operation of a user. 
     In the blood vessel, blood flows into the internal space  34 S of the housing  34 , and the blood pressure acts on the surface of the diaphragm  13  of the pressure sensor  11 . Thus, the diaphragm  13  is elastically deformed, and then the electrical resistance values of the four resistors  17  accordingly vary. 
     In the blood flow, pulsation occurs in which an increase and a decrease of the blood pressure are repeated by the motion of the heart. The four resistors  17  are elastically deformed following the pulsation of the blood flow. Thus, the electrical resistance values of the four resistors  17  vary corresponding to the pulsing blood pressure of the blood flow. 
     The calculation portion  42  of the calculation control portion  40  acquires the electric information to be output from the pressure sensor  11 . The calculation portion  42  calculates the blood pressure acting on the pressure sensor  11  based on the electric information as described above. 
     &lt;Operational Effects of First Embodiment&gt; 
     According to the pressure measurement device  10  of the first embodiment, the four resistors  17  are fixed to the outer peripheral portion of the diaphragm  13 . Therefore, when the diaphragm is elastically deformed by the pressure (blood pressure) of a fluid in a lumen (blood vessel), the electrical resistance values of the four resistors  17  individually vary. Therefore, the gain of the sensor  11  increases. 
     The shape of the diaphragm  13  is a disk shape, and therefore, when the diaphragm  13  is elastically deformed, the deformation amount of the outer peripheral portion of the diaphragm  13  is uniform irrespective of the position in the circumferential direction. The variation amount of the electrical resistance values of the resistors  17  is proportional to the deformation amount of the diaphragm  13  at the positions where the resistors  17  are fixed. Therefore, even when the positions of the resistors  17  to the diaphragm  13  somewhat shift due to variations in manufacturing and the like, for example, the resistance variation characteristic of the resistors  17 , i.e., the variation amount of the electrical resistance value to the pressure, does not sharply fluctuate. The resistance variation characteristic is kept uniform in the four resistors  17 , and therefore a fluctuation of the gain of the sensor  11  due to variations in manufacturing is small. 
     Each terminal  18  is disposed between the two adjacent resistors  17 , and therefore the path length of the bridge circuit  14  is shortened as compared with a case where each terminal  18  is disposed at a position deviated from the position between the two resistors  17 . Thus, the size reduction in the sensor  11  is achieved. 
     Each of the conductive wires  15  is connected to a portion (distal electroconductive layer  24 ) laminated on the distal end surface  12   a  of the sensor body  12 . Therefore, the conductive wires  15  are not disposed on the outer peripheral surface  12   c  of the sensor body  12 . 
     A fluid in a lumen does not contact the connection portion  26 , and therefore a degradation of the connection portion  26  is suppressed and the connection portion  26  is waterproofed and insulated. 
     The vibration caused by the contact between the distal end portion (tip guide portion  32 ) of the guide wire  30  and the wall surface in a lumen is difficult to be transmitted to the sensor  11 , and therefore the detection accuracy of the sensor  11  increases. 
     [Modification of First Embodiment] 
     As described above, although the embodiment of the present invention is described in detail, the description above is merely exemplary of the present invention in all points. It is a matter of course that various improvements or modifications can be performed without deviating from the scope of the present invention. With respect to the constituent components of the pressure measurement device  10  according to the first embodiment, constituent components may be omitted, replaced, and added as appropriate according to embodiments. Moreover, the shapes and the sizes of the constituent components of the pressure measurement device  10  may also be set as appropriate according to embodiments. For example, the following alternations can be performed. 
     In the first embodiment, the shape of the sensor body  12  is a cylindrical shape and the distal end surface  12   a  is vertical to the axial direction  30 A of the guide wire  30 . The sensor body  12  may have the distal end surface  12   a  facing the distal side and the shape of the sensor body  12  and the angle of the distal end surface  12   a  with respect to the axial direction  30 A are not limited. The shape of the sensor body  12  may be a square columnar shape, for example, and the distal end surface  12   a  may be inclined with respect to the axial direction  30 A. 
     In the first embodiment, the shape of the diaphragm  13  is a disk shape. The shape of the diaphragm  13  is not limited insofar as the shape allows the diaphragm  13  to be elastically deformed according to a variation in the pressure applied to the diaphragm  13 . The diaphragm  13  may be a plate-like member and the shape when the plate-like member is viewed from the axial direction  30 A may be an arbitrary shape. The arbitrary shape is a polygonal shape and includes a square shape, a hexagonal shape, an octagonal shape, and the like, for example. 
     In the first embodiment, the coating member  16  contains an adhesive but the present invention is not limited thereto. The coating member  16  may be a rigid component and may be a component to be fixed to the proximal end surface  12   b  of the sensor body  12 , for example. 
     In the first embodiment, the coating member  16  not only covers the connection portion  26  but fixes the pressure sensor  11  to the tapered pin  39 . The coating member  16  may only cover the connection portion  26 . In this case, the pressure sensor  11  is fixed to the tapered pin  39  by another member. 
     In the first embodiment, the four resistors  17  are disposed at 90° intervals around the axial center line of the sensor body  12 . The arrangement of the four resistors  17  is not limited insofar as the four resistors  17  are disposed along the circumferential direction  30 C in the outer peripheral portion of the diaphragm  13 . The four resistors  17  may be disposed around the axial center line of the sensor body  12  at uneven intervals, such as intervals of 120°, 60°, 120°, and 60° or intervals of 60°, 90°, 30°, and 180°, for example. 
     In the first embodiment, the four through-holes  22  for providing the four terminals  18  are disposed at 90° intervals around the axial center line of the sensor body  12 . The arrangement of the four through-holes  22  is not limited insofar as each through-hole  22  is disposed between the two adjacent resistors  17  along the circumferential direction  30 C. The four through-holes  22  may be disposed around the axial center line of the sensor body  12  at uneven intervals, such as intervals of 120°, 60°, 120°, and 60° or intervals of 60°, 90°, 30°, and 180°, as with the four resistors  17 . Moreover, in the first embodiment, the shape of the through-holes  22  as viewed from the axial direction  30 A is a circular shape. The shape of the through-holes  22  as viewed from the axial direction  30 A may be a polygonal shape, for example, and is not limited. 
     In the first embodiment, it is desirable that waterproofing and insulation coating is performed to the entire or a part of the outer surface of the body of sensor  12  to such an extent that the movement of the diaphragm  13  of the sensor body  12  is not hindered. In particular, Parylene (Registered Trademark) coating is desirable but the coating method is not particularly limited. 
     Second Embodiment 
     &lt;Guide Wire System  110 &gt; 
     As illustrated in  FIG. 8 , a guide wire system  110  according to a second embodiment is provided with a guide wire  130 , a calculation device  120 , and a connector  140  connecting the guide wire  130  and the calculation device  120 . The guide wire  130  is a long and narrow cable and can be inserted into blood vessels, such as coronary arteries. The guide wire  130  is provided with a pressure sensor  111  ( FIG. 10 ) outputting electric information according to the pressure in a blood vessel. 
     The calculation device  120  is provided with a power supply portion  121  supplying a current to the pressure sensor  111  of the guide wire  130 , a calculation portion  122  performing calculation processing of the electric information to be output from the pressure sensor  111 , and a memory  123  storing information required for the calculation processing. The electric information to be output from the pressure sensor  111  is transmitted to the calculation portion  122  from the guide wire  130  via the connector  140 . The calculation portion  122  calculates the blood pressure based on the electric information to be output from the pressure sensor  111 . More specifically, the guide wire system  110  is used for the blood pressure measurement. 
     In  FIG. 8 , a fixed end (end connected to the calculation control device  120 ) is a proximal end (lower left end in  FIG. 8 ) of both ends of the guide wire  30  and a free end (tip when inserted into a blood vessel) thereof is a distal end (upper left end in  FIG. 8 ). Hereinafter, in the guide wire  130 , the side where the proximal end is present is referred to as a proximal side and the side where the distal end is present is referred to as a distal side. 
     &lt;Guide Wire  130 &gt; 
       FIG. 9  illustrates the guide wire  130 . In  FIG. 9 , the left side is the distal side of the guide wire  130  and the right side is the proximal side of the guide wire  130 . The guide wire  130  is provided with a tip guide portion  132 , a first spiral body  133 , a housing  134 , a second spiral body  135 , an electrode pipe  136 , four contacts  137 , a tapered pin  138 , and a tip guide pin  139 . A core wire  131  extends from the proximal end to the distal side. The tip guide portion  132  is disposed at the distal end. The first spiral body  133 , the housing  134 , the second spiral body  135 , and the electrode pipe  136  are disposed in order toward the proximal end from the tip guide portion  132  at the distal end. The four contacts  137  are disposed on the outer periphery side of the electrode pipe  136  and are arranged along an axis line  130 A of the guide wire  130 . The axis line  130 A refers to the axis line of the guide wire  130  when the guide wire  130  is in a straight state without being deflected or curved. 
     The core wire  131  is a member configuring the skeleton of the guide wire  130 . The tip guide portion  132  is a hemispherical member which is disposed at the distal end and protrudes to the distal side and which abuts on a blood vessel wall to thereby guide the movement direction of the guide wire  130  along the blood vessel. The first spiral body  133  and the second spiral body  135  are spirally wound wire rods and configured so as to be easier to bend than the core wire  131  so that a distal end portion of the guide wire  130  is easy to conform to a blood vessel. The housing  134  is a casing accommodating the pressure sensor  111  in the internal space. The housing  134  has two through-holes  134   a . Blood can contact the pressure sensor  111  ( FIG. 10 ) disposed inside the housing  134  through the through-holes  134   a . The electrode pipe  136  is a cylindrical member accommodating four conductive wires  115  ( FIG. 10 ) extending from the pressure sensor  111  and is fixed to a proximal end portion of the core wire  131 . The four contacts  137  are individually connected to the four conductive wires  115  ( FIG. 10 ) and fixed to the outer peripheral surface of the electrode pipe  136 . The shape of the contact  137  is an annular shape ( FIG. 18 ). The tapered pin  138  is a member reinforcing the bending rigidity of the second spiral body  135 , fixed to a distal end portion of the core wire  131 , and extends from the core wire  131  to the housing  134 . The tip guide pin  139  is a member reinforcing the bending rigidity of the first spiral body  133  and is fixed to the housing  134  and the tip guide portion  132 . 
     As illustrated in  FIG. 10 , the pressure sensor  111  is provided with a sensor body  112 , a diaphragm  113 , a bridge circuit  114 , four conductive wires  115 , and a connection portion  116 , for example. The sensor body  112  is fixed to a tapered pin  138  fixed to the core wire  131  by the connection portion  116  containing an adhesive, for example. To the sensor body  112 , the diaphragm  113 , the bridge circuit  114 , and the four conductive wires  115  are attached. The bridge circuit  114  is a full bridge circuit in which four resistors  117  all function as a distortion gauge for measurement. The bridge circuit  114  is provided with the four resistors  117 , four terminals  118 A and  118 B, and four connection bodies  119 . The four resistors  117  are fixed to the diaphragm  113 . The four terminals  118 A and  118 B contain two input terminals  118 A and two output terminals  118 B. Each connection body  119  electrically connects each of the resistors  117  to each of the terminals  118 A and  118 B. Each of the conductive wires  115  is electrically connected to each of the terminals  118 A and  118 B. 
     In a state where the guide wire  130  is inserted into a blood vessel, so that blood pressure is applied to the pressure sensor  111 , the diaphragm  113  is elastically deformed according to the blood pressure. The four resistors  117  are elastically deformed with the elastic deformation of the diaphragm  113 , so that the electrical resistance values of the four resistors  117  vary. When a voltage is applied between the two input terminals  118 A in this state, a potential difference is generated between the two output terminals  118 B. Based on the potential difference, the magnitude of the blood pressure can be specified in the calculation device  120  ( FIG. 8 ). 
     &lt;Connector  140 &gt; 
     As illustrated in  FIG. 11 , the connector  140  is provided with a holding component (example of the holding portion)  141  holding the guide wire  130  and a connector body  142  to which the holding component  141  is attached. The connector body  142  is provided with a cable  143  electrically connected to the four conductive wires  115 . The cable  143  is electrically connected to the calculation device  120  ( FIG. 8 ). 
     In  FIG. 11 , a first direction  124  and a second direction  125  are directions orthogonal to the axis line  130 A. The first direction  124  and the second direction  125  are orthogonal to each other. Hereinafter, the attitude of the connector  140  is described using the first direction  124  and the second direction  125 .  FIG. 13(A)  and  FIG. 14(A)  are cross-sectional views cut by the plane including the axis line  130 A and in parallel to the first direction  124 .  FIG. 13(B)  and  FIG. 14(B)  are cross-sectional views cut by the plane including the axis line  130 A and in parallel to the second direction  125 . 
       FIG. 12  is an exploded perspective view of the connector  140 . The connector body  142  is provided with a tubular cover  145 , a terminal case  146 , a guide component (example of the guide portion)  147 , and a support component (example of the support portion)  148 . 
     The holding component  141  is illustrated in  FIG. 12  to  FIG. 14 . As illustrated in  FIG. 12 , the holding component  141  is provided with a body  150 , two holding pieces  151 , and two hook portions  152 . The holding component  141  is molded by a resin material. Therefore, the body  150 , the two holding pieces  151 , and the two hook portions  152  are integrally molded. 
     The shape of the body  150  is schematically a tubular shape in which an insertion hole  150   a  which is the internal space extends along the axis line  130 A. The guide wire  130  can be inserted into and passed through the insertion hole  150   a . The body  150  is provided with a fitting portion  153  in a proximal end portion. The shape of the fitting portion  153  is a disk shape with the axis line  130 A as the axis and projects outward in the radial direction. The fitting portion  153  is fitted to the guide component  147  by being combined with the connector body  142  as the holding component  141  and regulates the movement of the holding component  141  in a direction of being inserted into the connector body  142 . Moreover, the fitting portion  153  abuts on a lock portion  169  of the support component  148  to thereby prevent the holding component  141  which is inserted into the connector body  142  once from easily falling off from the connector body  142 . 
     The two holding pieces  151  extend along the axis line  130 A from the proximal end (left side of  FIG. 12 , right side of  FIG. 13 ) of the body  150 . The two holding pieces  151  face each other in the second direction  125 . The shape of each of the two holding pieces  151  is a semicylindrical shape extending along the axis line  130 A. When the two holding pieces  151  approach each other to abut on each other, a substantially cylindrical shape is formed. The two holding pieces  151  are apart from each other in the second direction  125  in a state where no external force is given. In the holding pieces  151 , the proximal end sides can be elastically deformed in a direction of approaching each other with the connection position between each of the holding pieces  151  and the body  150 , i.e., distal end of each of the holding pieces  151 , as a fulcrum. The guide wire  130  is inserted into and passed through the holding component  141  through space serving as the internal space when the two holding pieces  151  form the cylindrical shape. Due to the fact that a proximal end portion of each of the holding pieces  151  abuts on the guide component  147 , the two holding pieces  151  are elastically deformed so as to approach each other. Thus, the guide wire  130  is held by the two holding pieces  151 . 
     The two hook portions  152  extend along the axis line  130 A toward the proximal side (left side of  FIG. 12 , right side of  FIG. 13 ) from the distal end (left side of  FIG. 12 , right side of  FIG. 13 ) of the body  150 . In the second direction  125 , the body  150  is located between the two hook portions  152 . In the hook portions  152 , the proximal end sides can be elastically deformed inward in the radial direction with respect to the axis line  130 A with the connection position between each of the hook portions  152  and the body  150 , i.e., distal end of each of the hook portions  152 , as a fulcrum. Recessed portions  152   a  are formed in a proximal end portion of each of the hook portions  152 . Each recessed portion  152   a  is recessed inward in the radial direction with respect to the axis line  130 A in each of the hook portions  152 . Each recessed portion  152   a  can be engaged with the lock portion  169  of the support component  148 . Due to the fact that each recessed portion  152   a  is engaged with the lock portion  169  of the support component  148 , the relative movement of the holding component  141  along the axis line  130 A with respect to the connector body  142  is regulated. 
     The tubular cover  145  is illustrated in  FIG. 12  to  FIG. 14 . The tubular cover  145  accommodates the terminal case  146  accommodating terminals  144 , the guide component  147 , and the support component  148  which are disposed in order from the proximal side (lower left side of  FIG. 12 ) toward the distal side (upper right side of  FIG. 12 ). The terminal case  146 , the guide component  147 , and the support component  148  accommodated in the tubular cover  145  are assembled to each other to be integrated. 
     The shape of the tubular cover  145  is schematically a tubular shape extending along the axis line  130 A. The outer shape of the proximal end side of the tubular cover  145  is a rectangular tubular shape. The proximal end of the tubular cover  145  is sealed and a cable hole  145   a  penetrated along the axis line  130 A is formed. The cable  143  is extended from the inside of the tubular cover  145  to the outside through the cable holes  145   a . The distal end side of the tubular cover  145  has a cylindrical shape. Around the distal end of the peripheral wall of the tubular cover  145 , two engagement holes  145   b  penetrated in the radial direction with respect to the axis line  130 A are formed. The two engagement holes  145   b  face each other in the first direction  124 . A convex portion  168  of the support component  148  is engaged with each engagement hole  145   b . The distal end of the tubular cover  145  is opened. 
     As illustrated in  FIG. 12  to  FIG. 15 , the terminal case  146  is provided with the four terminals  144  ( FIG. 13  to  FIG. 18 ) individually electrically connected to the four contacts  137  of the guide wire  130 . As illustrated in  FIG. 15 , the terminal case  146  is provided with an inner case  154  accommodating the four terminals  144 , a connection plate  155  to which the cable  143  is fixed, an outer case  156  accommodating the inner case  154  and the connection plate  155 , and a wire guide component  157 . 
     As illustrated in  FIG. 15 , the cable  143  has four conductive wires  126  and a protective coating film  127  covering the four conductive wires  126 . The four conductive wires  126  are individually electrically connected to the four terminals  144  in the terminal case  146 . 
     The inner case  154  is a long and narrow rectangular parallelepiped configured by combining a first case piece  158  and a second case piece  159 . The first case piece  158  and the second case piece  159  face each other in the first direction  124  and long and narrowly extends along the axis line  130 A. Between the first case piece  158  and the second case piece  159 , space  160  extending along the axis line  130 A is formed. In the space  160 , the four terminals  144  are arranged side by side along the axis line  130 A. The distal end of the inner case  154  is opened and the space  160  is continuous to the outside through the opening. 
     The connection plate  155  is a plate facing the first case piece  158  and the second case piece  159  in the first direction  124 . The second case piece  159  is adjacent to the connection plate  155 . In the second case piece  159 , four terminal holes  154   a  are formed along the first direction  124 . In the connection plate  155 , four terminals holes  151   a  are provided along the first direction  124 . Each terminal hole  151   a  of the connection plate  155  is continuous to each terminal hole  154   a  of the second case piece  159 . A connection portion  170  of the terminal  144  is inserted into and passed through one pair of the terminal hole  154   a  and the terminal hole  151   a.    
     Between the connection plate  155  and the outer case  156 , spaces  161  and  162  along the axis line  130 A are formed on both sides in the first direction  124 . In the space  161 , the inner case  154  and a distal end portion of the protective coating film  127  of the cable  143  are disposed. In the space  162 , the four connection portions  170  of the four terminals  144  project, the four conductive wires  126  of the cable  143  are disposed, and each of the connection portions  170  is electrically connected to each of the conductive wires  126  by soldering. Some conductive wires  126  are illustrated in a broken state for convenience of illustration. 
     The outer case  156  has a substantially square tubular shape. In a distal end portion of the outer case  156 , a first recessed portion  156   a  and a second recessed portion  156   b  of a cylindrical shape opened to the distal side are formed. The internal space of the first recessed portion  156   a  is continuous to the internal space of the inner case  154  accommodated in the outer case  156 . The first recessed portion  156   a  and the second recessed portion  156   b  each have internal space along the axis line  130 A. The wire guide component  157  is fitted to the first recessed portion  156   a . A first tube portion  164  of the guide component  147  is fitted to the second recessed portion  156   b.    
     The wire guide component  157  is a component positioning the guide wire  130  inserted into the connector  140  along the axis line  130 A. The wire guide component  157  has a through-hole having a cylindrical shape and penetrated along the axis line  130 A. The inner surface of the through-hole has two tapered surfaces  157   a  which are individually disposed on the distal side and the proximal side and the diameter of which individually decreases toward the center and a circumferential surface  157   b  connecting the two tapered surfaces  157   a . The inner diameter of the circumferential surface  157   b  is somewhat larger than the outer diameter of the guide wire  130 . The minimum diameter of the tapered surface  157   a  is equal to the inner diameter of the circumferential surface  157   b  and the maximum diameter of the tapered surfaces  157   a  is larger than the inner diameter of the circumferential surface  157   b . Each tapered surface  157   a  is tapered toward the circumferential surface  157   b . Therefore, the guide wire  130  inserted into the wire guide component  157  is guided so as to be coaxial with the axis line  130 A by the circumferential surface  157   b.    
     The guide component  147  is illustrated in  FIG. 12  to FIG.  14 . The guide component  147  is a component guiding the holding component  141  so that distal portions of the two holding pieces  151  of the holding component  141  are elastically deformed when the holding component  141  is slid along the axis line  130 A. 
     As illustrated in  FIG. 12 , the guide component  147  is provided with a first tube portion  164 , a guide portion  165 , and a second tube portion  166  (example of the fitting target portion) disposed in order from the proximal side (lower left side of  FIG. 12 ) toward the distal side (upper right side of  FIG. 12 ). The first tube portion  164 , the guide portion  165 , and the second tube portion  166  are integrally molded. The shape of the first tube portion  164  is a bottomed cylindrical shape and the first tube portion  164  has a through-hole  164   a  along the axis line  130 A. The guide wire  130  is inserted into and passed through the through-hole  164   a . The first tube portion  164  is fitted to the second recessed portion  156   b  of the terminal case  146  from the outside so as to be rotatable around the axis line  130 A. The guide portion  165  is rotatable with respect to the terminal case  146 . 
     As illustrated in  FIG. 12 , the shape of the guide portion  165  is a tubular shape with a tapered inner surface. As illustrated in  FIG. 13  and  FIG. 14 , the inner surface of the guide portion  165  is a guide surface  165   a  formed along the axis line  130 A. The guide surface  165   a  is a tapered surface tapered toward the proximal side (right side of  FIG. 13  and  FIG. 14 ). 
     As illustrated in  FIG. 12  to  FIG. 14 , the shape of the second tube portion  166  is a schematically cylindrical shape. The inner diameter and the outer diameter of the second tube portion  166  are gradually vary in three steps so that the second tube portion  166  expands toward the distal side along the axis line  130 A. To the distal side of the second tube portion  166 , the support component  148  is fitted. To the internal space of the second tube portion  166 , the fitting portion  153  of the body  150  is fitted 
     The support component  148  is illustrated in  FIG. 12  to  FIG. 14 . The support component  148  is a component supporting the holding component  141  rotatably around the axis line  130 A. The support component  148  is provided with a body  167 , two convex portions  168 , and a lock portion  169 . The shape of the body  167  is a cylindrical shape having internal space extending along the axis line  130 A. Each convex portion  168  projects outward in the radial direction with respect to the axis line  130 A from the outer peripheral surface of the body  167 . The two convex portions  168  are disposed facing each other in the first direction  124  corresponding to the two engagement holes  145   b  of the tubular cover  145 . The lock portion  169  projects inward in the radial direction with respect to the axis line  130 A from the inner peripheral surface of the body  167 . The lock portion  169  is a protrusion continuously extending around the axis line  130 A. In a state where the recessed portions  152   a  of the hook portion  152  of the holding component  141  are engaged with the lock portion  169 , the movement along the axis line  130 A of the holding component  141  is regulated by the lock portion  169  and the holding component  141  is guided by the lock portion  169  to be rotatable around the axis line  130 A. 
     With reference to  FIG. 13  and  FIG. 14 , the connector  140  in a non-lock state and in a lock state is described.  FIG. 13  illustrates the connector  140  in the non-lock state.  FIG. 14  illustrates the connector  140  in the lock state. 
     The connector body  142  can be disassembled as illustrated in  FIG. 12  and the terminal case  146 , the guide component  147 , and the support component  148  are accommodated in the tubular cover  145  and assembled to each other to be integrated. The holding component  141  is attachable to and detachable from the connector body  142 . 
     When the removed holding component  141  is attached to the connector body  142 , the holding component  141  is inserted with the holding pieces  151  as the insertion front side from the distal side (left side of  FIG. 13 ) toward the proximal side (right side of  FIG. 13 ) of the connector body  142 . The outer diameter of the fitting portion  153  is somewhat larger than the outer diameter of the lock portion  169 . However, the fitting portion  153  is formed of a resin material, and therefore can be elastically deformed. Therefore, external force is applied so that the holding component  141  is pressed into the connector body  142 , whereby the fitting portion  153  can move to the proximal side over the lock portion  169 . When the fitting portion  153  is located on the proximal side of the lock portion  169 , the fitting portion  153  abuts on the lock portion  169 , whereby the holding component  141  is prevented from falling off from the connector body  142 . Moreover, external force is applied so that the holding component  141  is pulled out from the connector body  142 , whereby the fitting portion  153  moves to the distal side over the lock portion  169 , so that the holding component  141  is removed from the connector body  142 . 
     When the fitting portion  153  is located on the proximal side of the lock portion  169 , the non-lock state and the lock state of the connector  140  can be switched. When the fitting portion  153  is not fitted to the second tube portion  166  of the guide component  147 , the connector  140  is in the non-lock state ( FIG. 13 ). When the fitting portion  153  is fitted to the second tube portion  166  of the guide component  147 , the connector  140  is in the lock state ( FIG. 14 ). In the non-lock state, the guide wire  130  is not locked to the connector  140 . In the non-lock state, the holding pieces  151  are located in the guide portion  165  but do not abut on to the guide surface  165   a . The two holding pieces  151  are kept in a separated state, and therefore, even when the guide wire  130  is inserted into the connector  140 , the two holding pieces  151  do not hold the guide wire  130 . 
     External force is applied so as to sandwich the two hook portions  152 , whereby the two hook portions  152  are elastically deformed to move inward in the radial direction. Thus, the proximal ends of the hook portions  152  are located inside in the radial direction relative to the lock portion  169 , so that the proximal ends of the hook portions  152  can move to the proximal end side of the connector body  142  relative to the lock portion  169 . When the holding component  141  further moves to the proximal side, the fitting portion  153  is fitted to the second tube portion  166  to abut on the same, so that the holding component  141  is inhibited from further moving to the proximal side of the connector body  142 . In the state where the fitting portion  153  is fitted to the second tube portion  166 , the recessed portions  152   a  of the hook portion  152  face the lock portion  169 . When the external force applied to the two hook portions  152  is released, the hook portion  152  which is elastically restored move outward in the radial direction, so that the recessed portions  152   a  and the lock portion  169  are engaged with each other. As a result, the connector  140  is brought into the lock state illustrated in  FIG. 14 . In the lock state, the holding component  141  cannot relatively move in a direction along the axis line  130 A with respect to the connector body  142  but the holding component  141  is rotatable around the axis line  130 A with respect to the connector body  142 . 
     The guide wire  130  is inserted into the connector  140  in the non-lock state. The guide wire  130  is inserted from the insertion hole  150   a  of the holding component  141  through a gap between the two holding pieces  151  and the wire guide component  157  until the proximal end of the guide wire  130  abuts on the inner wall of the proximal end of the inner case  154 . At this time, the four contacts  137  of the guide wire  130  individually contact the four terminals  144  in the space  160 . 
     By the movement of the holding component  141  to the proximal side with respect to the connector body  142 , the connector  140  is brought into the lock state from the non-lock state. At this time, by the movement of the proximal end portions of the holding pieces  151  to the proximal side while abutting on the guide surface  165   a , the proximal end portions of the two holding pieces  151  are elastically deformed so as to mutually move inward in the radial direction. Thus, the guide wire  130  inserted into the connector  140  is held so as to be held between the two holding pieces  151 . Thus, the guide wire  130  is held so as not to be pulled out from the connector  140  depending on the external force applied to the guide wire  130  in a usual operation. Moreover, the guide wire  130  rotates integrally with the holding component  141 , and therefore, when the holding component  141  relatively rotates around the axis line  130 A with respect to the connector body  142 , the guide wire  130  also relatively rotates around the axis line  130 A with respect to the connector body  142  together with the holding component  141 . Herein, the holding pieces  151  abut on the guide surface  165   a , and therefore the guide component  147  also rotates together with the holding component  141 . 
     In the connector  140  in the lock state, the two hook portions  152  are moved inward in the radial direction by external force, whereby the recessed portions  152   a  of the hook portion  152  are separated from the lock portion  169 , so that the holding component  141  becomes movable along the axis line  130 A. In this state, the holding component  141  is moved to the distal side with respect to the connector body  142 , whereby the connector  140  is brought into the non-lock state from the lock state. 
     &lt;Terminal  144 &gt; 
     The terminal  144  is described with reference to  FIG. 16  to  FIG. 18 . As illustrated in  FIG. 16  and  FIG. 17 , the terminal  144  is provided with the connection portion  170 , a first connection portion  171 , three terminal portions  172 , and a second connection portion  173 . The material of the terminal  144  is metal which has conductivity and can be subjected to bending processing and is preferably spring steel. The connection portion  170 , the first connection portion  171 , the three terminal portions  172 , and the second connection portion  173  are integrally formed by performing punching and bending processing of a metal plate. 
     The connection portion  170  is a portion electrically connected to the conductive wire  126  of the cable  143 . The connection portion  170  has a long and narrow flat plate shape bent into an L shape. The first connection portion  171  and the second connection portion  173  individually connect both ends in the axis line  130 A of the three terminal portions  172 . The first connection portion  171  and the second connection portion  173  each have a substantially cylindrical shape. 
     The three terminal portions  172  are disposed around the axis line  130 A. The terminal portions  172  have the same shape and individually have a long and narrow plate shape along the axis line  130 A, and the center in a direction along the axis line  130 A is curved so as to swell inward in the radial direction. The angle θ serving as the pitch (interval) around the axis line  130 A in the adjacent terminal portions  172  is 120° ( FIG. 18(A) ). In other words, the center or one edge of a surface directed in the axis line  130 A in each of the terminal portions  172  is individually different in phase by 120°. 
     The inner surface of the terminal portions  172  is a contact surface  172   a  facing the contact  137  of the guide wire  130 . As illustrated in  FIG. 16  and  FIG. 17(C) , the cross section of the contact surface  172   a  cut along the plane including the axis line  130 A is curved so as to protrude inward in the radial direction with respect to the axis line  130 A. Moreover, as illustrated in  FIG. 16  and  FIG. 17(A) , the contact surface  172   a  in the cutting plane orthogonal to the axis line  130 A is a straight line. When the guide wire  130  is held by the connector  140 , each of the contact surfaces  172   a  contacts the contact  137  in a portion closest to the axis line  130 A. The contact  137  is a circumferential surface, and therefore the contact between the contact surface  172   a  and the contact  137  is a so-called point contact. 
     The terminal portions  172  have elasticity as a plate spring by the curved shape. In a state where each of the contacts  137  of the guide wire  130  abuts on each of the terminal portions  172 , each of the terminal portions  172  is elastically deformed outward in the radial direction. 
     Changes in the positions of the three terminal portions  172  are described with reference to  FIG. 18 . Each view of FIG.  18  illustrates the cross section of the terminal  144  at the position closest to the axis line  130 A in the terminal portions  172 . 
       FIG. 18(A)  illustrates the positions of the terminal portions  172  in a natural state, i.e., a state where the contact  137  of the guide wire  130  does not abut on the terminal  144 . 
       FIG. 18(B)  illustrates the positions of the terminal portions  172  in a state where the contact  137  of the guide wire  130  abuts on the terminal  144 . The radius of the outer peripheral surface of the contact  137  is larger than the shortest distance from the axis line  130 A to the contact surfaces  172   a  of the terminal portions  172 . Therefore, each of the terminal portions  172  is elastically deformed outward in the radial direction by abutting on the contact  137 . Thus, each of the contact surfaces  172   a  move outward in the radial direction from the natural state. The axis line of the guide wire  130  in  FIG. 18(B)  is in agreement with the axis line  130 A in the connector  140 . Therefore, the contact surface  172   a  of each of the terminal portions  172  is located at a position apart from the axis line  130 A corresponding to a distance equal to the radius of the outer peripheral surface of the contact  137 . Each of the terminal portions  172  is elastically deformed, and therefore each of the terminal portions  172  is energized toward the contact  137  by the restoring force. Thus, each of the terminal portions  172  pressure-contacts the contact  137 , so that the electrical connection between the terminal  144  and the contact  137  is maintained. 
       FIG. 18(C)  also illustrates the positions of the terminal portions  172  in the state where the contact  137  of the guide wire  130  abuts on the terminal  144 . An axis line  130 B of the guide wire  130  in  FIG. 18(C)  is located at a position deviated from the axis line  130 A of the connector  140 . Such a state occurs by performing an operation of rotating the guide wire  130  or the like by a user. The operation of the guide wire  130  is performed when moving the guide wire  130  forward and backward within a blood vessel, for example. For example, when the guide wire  130  rotates, the holding component  141  holding the guide wire  130  also rotates together. The holding component  141  is rotatably supported by the support component  148 . Therefore, the guide wire  130  rotates relatively to the connector body  142  laid on a desk, for example. The rotation of the connector body  142  is suppressed by abutting of an outer shape portion of a rectangular shape of the tubular cover  145  on the placement surface of the desk, for example. 
     When the guide wire  130  rotates relatively to the connector body  142 , the contact  137  of the guide wire  130  rotates relatively to the terminals  144  of the connector  140 . The holding component  141  holding the guide wire  130  rotates relatively to the connector body  142 , and therefore a tolerance or a backlash is present therebetween. By a rotation torque of the guide wire, the holding component  141  rattles with respect to the connector body  142 . As a result, the contact  137  moves in the radial direction, so that the axis line  130 B of the guide wire  130  is deviated from the axis line  130 A of the connector  140 . Thus, even when the contact  137  moves in the radial direction, the three terminal portions  172  follow the movement of the contact  137  by the energization force generated by the elastic deformation of the three terminal portions  172 . Therefore, the electrical connection between the three terminal portions  172  and the contact  137  is maintained. In addition thereto, the contact  137  is returned to the position of the axis line  130 A by the balance of the energization force of the three terminal portions  172 , and therefore the position of the contact  137  is likely to return to the position of  FIG. 18(B)  from the position of  FIG. 18(C) . 
     &lt;Use Example of Guide Wire System  110 &gt; 
     The guide wire system  110  is used for measuring the blood pressure in coronary arteries, for example. The guide wire  130  is inserted into the coronary arteries with the distal end where the tip guide portion  132  is provided as the head in the insertion direction into a blood vessel. 
     When the pressure sensor  111  reaches the blood pressure measurement position in the coronary arteries, the insertion of the guide wire  130  is interrupted. In such a state, a fixed voltage is supplied to the pressure sensor  111  from the power supply portion  121  by an operation of a user. 
     In a blood vessel, blood flows into the internal space of the housing  134 , so that the blood pressure acts on the surface of the diaphragm  113  of the pressure sensor  111 . Thus, the diaphragm  113  is elastically deformed, and accordingly the electrical resistance values of the four resistors  117  vary. 
     In the blood flow, pulsation occurs in which an increase and a decrease of the blood pressure are repeated by the motion of the heart. The four resistors  117  are elastically deformed following the pulsation of the blood flow. Thus, the electrical resistance values of the four resistors  117  vary corresponding to the pulsing blood pressure of the blood flow. 
     The calculation portion  122  of the calculation control device  120  acquires the electric information to be output from the pressure sensor  111 . The calculation portion  122  calculates the blood pressure acting on the pressure sensor  111  based on the electric information as described above. 
     When the blood pressure measurement position is changed during the blood pressure measurement, an operation of, for example, rotating or sliding the guide wire  130 , is performed as necessary in order to change the position of the guide wire  130 . When the guide wire  130  is operated, the contact  137  of the guide wire  130  moves in the radial direction by a rotation torque, for example. Each of the terminal portions  172  of the terminals  144  provided in the connector  140  follows the movement in the radial direction of the contacts  137 . Therefore, the electrical connection between the contacts  137  and the terminals  144  is maintained also in the situation where a rotation torque has been applied. Therefore, a jump or a drift is difficult to occur in data to be transmitted to the calculation device  120  from the pressure sensor  111 . 
     &lt;Operational Effects of Second Embodiment&gt; 
     According to the connector  140  of the second embodiment, the holding component  141  is slid along the axis line  130 A of the insertion hole  150   a  with respect to the support component  148 , whereby the holding pieces  151  abut on the guide surface  165   a  to be elastically deformed inward in the radial direction. As a result, the guide wire  130  is held by the holding pieces  151 . When slid in the opposite direction, the holding pieces  151  are separated from the guide surface  165   a , so that the hold of the guide wire  130  is released. Therefore, the guide wire  130  is held or the hold is released by sliding the holding component  141 . 
     Due to the fact that each recessed portion  152   a  is engaged with the lock portion  169  of the support component  148 , the relative movement of the holding component  141  along the axis line  130 A with respect to the support component  148  is regulated. 
     In the case where the holding pieces  151  abut on the guide surface  165   a , even in the state where the lock portion  169  is not temporarily engaged with the recessed portions  152   a  by the elastic deformation of the hook portions  152 , the fitting portion  153  is fitted to the second tube portion  166  to abut on the same, so that the movement of the holding component  141  to the proximal side of the support component  148  is inhibited. 
     The angle θ around the axis line  130 A of the guide wire  130  between the two adjacent terminal portions  172  satisfies the relationship of 90°&lt;θ&lt;180°. Therefore, even when the contacts  137  move in the radial direction so that the axis lines  130 A and  130 B of the guide wire  130  shift, the terminal portions  172  follow the movement of the contacts  137  by the elastic deformation of the terminal portions  172 . Therefore, a trouble that the electrical connection between the contacts  137  and the terminals  144  is momentarily cut is difficult to occur. 
     The angle θ satisfies the relationship θ=120°, and therefore the three terminal portions  172  are disposed at equal intervals. Therefore, even when the guide wire  130  moves in any direction of the radial directions, each of the terminal portions  172  follows the contact  137 . Therefore, the trouble that the electrical connection between the contact  137  and the terminal  144  is momentarily cut is more difficult to occur. 
     The terminal portions  172  point-contact the contacts  137  along the axis line  130 A of the guide wire  130 . Therefore, when the guide wire  130  moves along the axis line  130 A, the terminal portions  172  easily retreat in a direction of separating from the axis line  130 A. Accordingly, the guide wire  130  can be easily inserted into and removed from the connector  140 . 
     The lock portion  169  locks the slide at the position where the holding pieces  151  abut on to the guide surface  165   a  and enables the guide component  147  to rotate around the axis line  130 A of the guide wire  130 . Therefore, when the connector body  142  is placed on a work desk in the state where the guide wire  130  is held by the holding component  141 , the tubular cover  145  itself does not rotate and the guide component  147  and the holding component  141  become rotatable. Accordingly, the connector body  142  itself does not rotate by the vibration in the operation of the guide wire, and therefore the trouble that the electrical connection is momentarily cut is difficult to occur. 
     &lt;Contact Stability Data&gt; 
     An experiment method for confirming the contact stability of the terminals  144  and experimental results are described with reference to  FIG. 21  to  FIG. 23 . 
     An experiment of evaluating the electric contact stability as a female terminal was performed for the connector  140  according to the second embodiment and comparative articles. As the comparative articles, Combowire of Volcano and Certus of St Jude Medical were used. The comparative articles have a configuration in which members equivalent to the holding component  141  and the connector body  142  in the connector  140  are fixed by a screw system and do not relatively rotate (for example, refer to Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2001-516938). In order to simulate a state where a guide wire terminal electrode is connected for the connector  140  and the comparative articles, a ϕ0.36 mm gold-plated SUS pin having a diameter equal to that of a 0.014 mm guide wire was used as the male terminal. A 100Ω simulation resistance was connected to the proximal end side of a male terminal by soldering. The tip side of the male terminal was inserted into the female terminal, and then the contact resistance between the male terminal base end and the female terminal was evaluated. 
     For the evaluation of the contact resistance, an amplifier circuit containing a Wheatstone bridge was used. One amplifying and outputting a difference between the resistance (about 100Ω) between the male terminal base end and the female terminal and a reference resistance of 100Ω was designed and used. For the offset adjustment, the reference resistance was slightly increased/reduced from 100Ω to be set so that the baseline was 3 V. In this amplifier circuit, a 1 V variation of an output voltage is equivalent to a 0.5Ω variation of the contact resistance. The output voltage from the amplifier circuit was recorded by a data logger (YOKOGAWA, DL850). In the above-described connection state, the movement of the guide wire assumed during an operation was simulated and a vibration and a rotation were applied to the male terminal, and then a fluctuation of amplifier circuit outputs at that time was confirmed. The results are illustrated in  FIG. 21  to  FIG. 23 . It was confirmed in the connector  140  ( FIG. 21 ) that the amplifier output variation (i.e., contact resistance variation) when the vibration and the rotation are given to the male terminal is further suppressed than that of the comparative articles ( FIG. 22 ,  FIG. 23 ). This shows a possibility of suppressing a poor contact resulting from the movement of the guide wire during an operation and a drift of sensor outputs caused by the poor contact. 
     Third Embodiment 
     &lt;Terminal  244 &gt; 
     A terminal  244  according to a third embodiment is described with reference to  FIG. 19  and  FIG. 20 . A connector  140  according to the third embodiment is different from the connector  140  according to the second embodiment in the configuration of the terminal  244 . The third embodiment is the same as the second embodiment other than the point. Hereinafter, the configuration of the terminal  244  according to the third embodiment is described. The members common to those of the second embodiment are designated by the same reference numerals and a description of these members is omitted. 
     The terminal  244  is provided with a body  180  and a converging tube  181 . The body  180  is provided with the connection portion  170 , the first connection portion  171 , and three terminal portions  272 . The material of the body  180  is metal which has conductivity and can be subjected to bending processing and is preferably spring steel. The connection portion  170 , the first connection portion  171 , and the three terminal portions  272 , are integrally formed by performing punching and bending processing of a metal plate. 
     The terminal portions  272  are configured in the same manner as the terminal portions  172  according to the second embodiment except a point that one end in the axis line  130 A is opened. The inner surfaces of the terminal portions  272  are contact surfaces  272   a  facing the contact  137  of the guide wire  130  and the contact surfaces  272   a  are curved so as to protrude inward in the radial direction. 
     The converging tube  181  is externally fitted to one end in a direction along the axis line  130 A of the terminal portion  272 . The shape of the converging tube  181  is a cylindrical shape. The material of the converging tube  181  is a resin material. Therefore, the converging tube  181  can be elastically deformed so as to enlarge the diameter. 
     One end portion of each of the terminal portions  272  is supported by the first connection portion  171  and the other end portion is supported by the converging tube  181 . Therefore, the terminal portions  272  function as a plate spring when the contacts of the guide wire  130  are disposed inside the three terminal portions  272 . 
     &lt;Operational Effects of Third Embodiment&gt; 
     According to the connector  140  of the third embodiment, the converging tube  181  is externally fitted to the other end of each of the terminal portions  172  and can be elastically deformed so as to enlarge the diameter. The plate spring which is the terminal portion  172  is subject to not only the energization force the plate spring itself but the energization force caused by the first connection portion  171  which is a cylindrical spring. Therefore, the energization force of the terminal portions  172  can be easily adjusted. 
     [Modifications of Second Embodiment and Third Embodiment] 
     The embodiments of the present invention are described above in detail but the description above is merely exemplary of the present invention in all points. It is a matter of course that various improvements or modifications can be performed without deviating from the scope of the present invention. With respect to the constituent components of the connector  140  according to each embodiment, constituent components may be omitted, replaced, and added as appropriate according to embodiments. Moreover, the shapes and the sizes of the constituent components of the connector  140  may also be set as appropriate according to embodiments. For example, the following alternations can be performed. 
     In the second and third embodiments, although the terminals  144  and  244  are provided with the three terminal portions  172  and  272 , respectively, the present invention is not limited to the configuration. The terminals  144  and  244  may be provided with four or more of the terminal portions  172  and  272 , respectively. In this case, with respect to at least three terminal portions  172  and  272  of the four or more terminal portions  172  and  272 , respectively, the angle θ between the two adjacent terminal portions  172  and  272  satisfies the relationship of 90°&lt;θ&lt;180°. 
     In the second and third embodiments, although the angle θ between the two adjacent terminal portions  172  and  272  satisfies the relationship of θ=120°, the present invention is not limited to the configuration. The angle θ may be another angle insofar as the relationship of 90°&lt;θ&lt;180° is satisfied. The pitches (intervals) around the axis line  130 A may not be equal. 
     In the second and third embodiments, although the shapes of the contact surfaces  172   a  and  272   a  in the cross section along the axis line  130 A are curved shapes of protruding inward in the radial direction, the present invention is not limited to the configuration. The shapes of the contact surfaces  172   a  and  272   a  are not limited insofar as the shape allows the contact surfaces  172   a  and  272   a  to contact the contact  137 , i.e., a shape in which the distance between the contact surfaces  172   a  and  272   a  and the axis line  130 A is smaller than the radius of the contact  137  of the guide wire  130 . The shapes of the contact surfaces  172   a  and  272   a  may be curved surfaces or planes extending in parallel to the axis line  130 A. 
     In the second and third embodiments, although the shapes of the contact surfaces  172   a  and  272   a  in the cross section vertical to the axis line  130 A are linear shapes, the present invention is not limited to the configuration. The shapes of the contact surfaces  172   a  and  272   a  in this cross section may be a curve protruding to the axis line  130 A side or conversely a curve recessed to the axis line  130 A side. In the case of the curve recessed to the axis line  130 A, it is preferable that the curvature radii of the contact surfaces  172   a  and  272   a  are larger than the curvature radius of the outer surface of the contact  137  so as not to be resistance in the insertion/removal of the guide wire  130 . 
     In the second and third embodiments, although the connector  140  is provided with the four terminals  144  and  244 , the present invention is not limited to the configuration. The number of the terminals  144  and  244  may be the same as the number of the corresponding contacts  137  of the guide wire  130  and may be two, three, or five or more, for example. 
     In the second and third embodiments, although the proximal end side is elastically deformed inward in the radial direction with respect to the axis line  130 A to slide the holding component  141  to the guide component  147  with the distal end of each of the hook portions  152  as a fulcrum, the holding component  141  and the guide component  147  may be screw-fitted to each other, and the aspect is not particularly limited. Moreover, the number of the holding pieces  151  of the holding component  141  may be one or two or more and the body  150  and the holding pieces  151  of the holding component  141  may be separate members. 
     In the second and third embodiments, although the lock portion  169  is provided on the inner surface of the support component  148 , the support component  148  may be integrally formed with the tubular cover  145 , and then the lock portion  169  may be provided on the inner surface of the integrally molded tubular cover  145  itself. Moreover, the number of the lock portions  169  may correspond to the number of the corresponding recessed portions  152   a  of the holding component  141  and may be two, three, or five or more. 
     In the second and third embodiments, although the connector  140  is used for the pressure sensor  111 , the present invention is not limited to the pressure sensor and those capable of measuring the physical quantities of blood in a blood vessel may be acceptable. The measurement element may be a flow velocity sensor measuring the flow velocity of blood in a blood vessel, a flow volume sensor measuring the blood flow volume in a blood vessel, a temperature sensor measuring the temperature of blood, and the like, for example. 
     Fourth Embodiment 
     [Guide Wire System  310 ] 
     As illustrated in  FIG. 24 , a guide wire system  310  is provided with a guide wire  330 , a calculation device  320 , and a female type connector  340  connecting the guide wire  330  and the calculation device  320 . The guide wire  330  is a long and narrow cable and can be inserted into blood vessels, such as coronary arteries. The guide wire  330  is provided with a pressure sensor  311  (see  FIG. 26 , example of the sensor) outputting electric information according to pressure in a blood vessel in a distal end portion. 
     The calculation device  320  is provided with a power supply portion  321  supplying a current to the pressure sensor  311  of the guide wire  330 , a calculation portion  322  performing calculation processing of electric information to be output from the pressure sensor  311 , and a memory  323  storing information required for the calculation processing. The electric information to be output from the pressure sensor  311  is transmitted to the calculation portion  322  via the female type connector  340  and the cable  324  from the guide wire  330 . The calculation portion  322  calculates the blood pressure based on the electric information to be output from the pressure sensor  311 . More specifically, the guide wire system  310  is used for the blood pressure measurement. 
     In  FIG. 24 , a fixed end (end connected to the female type connector  340 ) is a proximal end (end on the lower left side in  FIG. 24 ) of both end portions of the guide wire  330  and a free end (tip when inserted in a blood vessel) thereof is a distal end (end on the upper left side in  FIG. 24 ). In this specification, in the guide wire  30 , the side on which the proximal end is present is defined as the proximal side and the side on which the distal end is present is defined as the distal side. 
     [Guide Wire  330 ] 
       FIG. 25  illustrates the guide wire  330 . In  FIG. 25 , the left side is the distal end side of the guide wire  330  and the right side is the proximal end surface of the guide wire  330 . The guide wire  330  is roughly divided into a tip portion  330 A (example of the distal end), a core wire  331  (example of the body), and a male type connector  339  (example of the connector). The tip portion  330 A has a tip guide portion  332 , a first spiral body  333 , a housing  334 , and a second spiral body  335 . The core wire  331  and the male type connector  339  are connected through a connection tube  336 . The tip portion  330 A, the core wire  331 , the connection tube  336 , and the male type connector  339  are linearly disposed along the axis line  350 . The axis line  350  refers to the axis line of the guide wire  330  in a state where the guide wire  330  is in a straight state without being bent or curved. 
     The core wire  331  is a cylindrical member configuring the skeleton of the guide wire  330  and is a stainless steel tube, for example. The tip guide portion  332  is a hemispherical member which is disposed at the distal end and protrudes to the distal end side and which abuts on a blood vessel wall to thereby guide the movement direction of the guide wire  330  along the blood vessel. The first spiral body  333  and the second spiral body  335  are spirally wound wire rods and configured so as to be easier to bend than the core wire  331  so that a distal end portion of the guide wire  330  easily moves along the blood vessel. 
     The housing  334  is a casing accommodating the pressure sensor  311  (example of the electronic component) in the internal space. The housing  334  has two through-holes  334   a . The two through-holes  334   a  are 180° symmetrically disposed with respect to the axis line  350 .  FIG. 24  illustrates only one through-hole  334   a . Blood enters the housing  334  through the through-holes  334   a  to contact a diaphragm  313  ( FIG. 26 ) of the pressure sensor  311 . 
     A tapered pin  338  extends in the internal space of the second spiral body  335  toward the housing  334  from the distal end of the core wire  331 . The tapered pin  338  is a member reinforcing the bending rigidity of the second spiral body  335 . The tapered pin  338  has a cylindrical shape and the outer diameter gradually decreases toward the housing  334  from the distal end of the core wire  331 . Although not illustrated in each figure, a tip guide pin extends in the internal space of the first spiral body  333  toward the tip guide portion  332  from the distal end of the housing  334 . The tip guide pin is a member having a cylindrical shape and reinforcing the bending rigidity of the first spiral body  333 . The tip guide pin is fixed to the housing  334  and the tip guide portion  332 . 
     As illustrated in  FIG. 26 , the pressure sensor  311  is provided with a sensor body  312 , the diaphragm  313 , a bridge circuit  314 , four conductive wires  315 , and a connection portion  316 . The sensor body  312  is fixed to the tapered pin  338  fixed to the core wire  331  by the connection portion  316  containing an adhesive, for example. To the sensor body  312 , the diaphragm  313 , the bridge circuit  314 , and the four conductive wires  315  are attached. The bridge circuit  314  is a full bridge circuit in which four resistors  317  all function as a distortion gauge for measurement. The bridge circuit  314  is provided with the four resistors  317 , four terminals  318 A and  318 B, and four connection bodies  319 . The four resistors  317  are fixed to the diaphragm  313 . The four terminals  318 A and  318 B contain two input terminals  318 A and two output terminals  318 B. Each of the connection bodies  319  electrically connects each of the resistors  317  to each of the terminals  318 A and the terminals  318 B. Each of the conductive wires  315  is electrically connected to each of the terminals  318 A and  318 B and extends toward the proximal end in the internal space of the core wire  331 . 
     In a state where the guide wire  330  is inserted into a blood vessel, so that blood pressure is applied to the pressure sensor  311 , the diaphragm  313  is elastically deformed according to the blood pressure. The four resistors  317  are elastically deformed with the elastic deformation of the diaphragm  313 , so that the electrical resistance values of the four resistors  317  vary. When a voltage is applied between the two input terminals  318 A in this state, a potential difference is generated between the two output terminals  318 B. Based on the potential difference, the blood pressure is calculated in the calculation device  320  ( FIG. 24 ). 
     As illustrated in  FIG. 27 , a tapered portion  341  in which the outer diameter decreases toward the proximal end and a small-diameter portion  342  extends from the tapered portion  341  to the proximal end are formed in a proximal end portion of the core wire  331 . The outer diameter of the small-diameter portion  342  is smaller than the outer diameter of the core wire  331  in the distal end relative to the tapered portion  341  and is a fixed outer diameter along the axis line  350 . The length along the axis line  350  of the small-diameter portion  342  is longer than the length along the axis line  350  of the connection tube  336 . The proximal end of the core wire  331  is opened and the four conductive wires  315  inserted into and passed through the internal space of the core wire  331  extend to the outside from the opening of the proximal end. 
     As illustrated in  FIGS. 25 and 27 , the connection tube  336  connects a proximal end portion of the core wire  331  and a distal end portion of the male type connector  339 . The connection tube  336  is a tube containing conductive materials, such as stainless steel, for example, and the proximal end and the distal end are individually opened. The outer diameter of the connection tube  336  is almost equal to the outer diameter on the distal end side relative to the tapered portion  341  of the core wire  331 . The inner diameter of the connection tube  336  is almost equal to the outer diameter of the small-diameter portion  342  of the core wire  331 . The inner surface of the connection tube  336  contacts the outer surface of the small-diameter portion  342 , whereby the connection tube  336  and the core wire  331  are electrically connected. In a state where the connection tube  336  is not fixed to the small-diameter portion  342  with an adhesive or the like, the connection tube  336  is movable along the axis line  350  with respect to the small-diameter portion  342 . In a state where the connection tube  336  is fixed to the small-diameter portion  342 , the connection tube  336  covers the four conductive wires  315  extending from the proximal end of the core wire  331 . 
     As illustrated in  FIGS. 25 and 27 , the male type connector  339  is obtained by inserting four electrode pins  345  into the internal space of a complex  344  of a cylindrical tube shape in which four electrode rings  337 A,  337 B,  337 C, and  337 D and five insulation rings  343  are alternately connected. 
     The electrode rings  337 A,  337 B,  337 C, and  337 D have a cylindrical shape and conductivity which allows the conduction between the inner surface and the outer surface. The electrode rings  337 A,  337 B,  337 C, and  337 D may be those formed of a conductive member, for example, or may be those obtained by plating the surface of a cylindrical member with a conductive member. The insulation rings  343  are those having a cylindrical shape and containing insulating materials, such as polyimide. The inner diameter and the outer diameter of the electrode rings  337 A,  337 B,  337 C, and  337 D and the inner diameter and the outer diameter of the insulation rings  343  are equal to each other, respectively. The complex  344  of the cylindrical tube shape is formed by individually disposing the electrode rings  337 A,  337 B,  337 C, and  337 D between the five insulation rings  343 , and then integrally fixing them. The length along the axis line  350  of each of the electrode rings  337 A,  337 B,  337 C, and  337 D and each of the insulation rings  343  may be the same or may be different from each other, for example. The outer diameter of the complex  344  is almost equal to the outer diameter of the connection tube  336 . 
     As illustrated in  FIG. 28 , the four electrode pins  345 A,  345 B,  345 C, and  345 D are columnar members different in the length along the axis line  350 . The four electrode pins  345 A,  345 B,  345 C, and  345 D are those containing conductive materials or those having a surface plated with a conductive member and those having an insulation-coated outermost surface. The outer diameters of the four electrode pins  345 A,  345 B,  345 C, and  345 D are equal to each other. In this specification, when a description is given while not particularly distinguishing the four electrode pins  345 A,  345 B,  345 C, and  345 D from each other, the four electrode pins  345 A,  345 B,  345 C, and  345 D are merely simply referred to as “electrode pins  345 ”. 
     As illustrated in  FIG. 28 , distal end portions of the four electrode pins  345 A,  345 B,  345 C, and  345 D are conduction portions  346  not having the insulation coat. The conduction portions  346  are connected to the conductive wires  315  in one-to-one correspondence. In the state where the four electrode pins  345 A,  345 B,  345 C, and  345 D are arranged while aligning the positions in a direction along the axis line  350  of the proximal end portions as illustrated in the figure, the positions in a direction along the axis line  350  of the conduction portions  346  of the distal end portions (conduction portions  346  located on the left side in  FIG. 28 ) do not overlap with each other. 
     The four electrode pins  345 A,  345 B,  345 C, and  345 D each have the two conduction portions  346 . The electrode pin  345 A with the shortest length along the axis line  350  among the four electrode pins has the conduction portion  346  not having the insulation coat at a position somewhat apart from a proximal end portion (end portion on the right side in  FIG. 28 ). The conduction portion  346  on the proximal end side of the electrode pin  345 A corresponds to a position in a direction along the axis line  350  of the electrode ring  337 A located on the most proximal end side in the complex  344 . 
     The electrode pin  345 B having the next shortest length has the conduction portion  346  at a position apart from the proximal end. The conduction portion  346  on the proximal end side of the electrode pin  345 B corresponds to a position in the direction along the axis line  350  of the second electrode ring  337 B from the proximal end in the complex  344 . In the state illustrated in  FIG. 28 , the positions in the direction along the axis line  350  (horizontal direction in  FIG. 28 ) of the conduction portion  346  on the proximal end side of the electrode pin  345 A and the conduction portion  346  on the proximal end side of the electrode pin  345 B do not overlap with each other. 
     Similarly, the conduction portion  346  on the proximal end side in the electrode pin  345 C having the third shortest length corresponds to the position in the direction along the axis line  350  of the third electrode ring  337 C from the proximal end in the complex  344 . The conduction portion  346  on the proximal end side in the longest electrode pin  345 D corresponds to the position in the direction along the axis line  350  of the fourth electrode ring  337 D from the proximal end in the complex  344 . In the state illustrated in  FIG. 28 , the positions in the direction along the axis line  350  of the conduction portions  346  of the four electrode pins  345 A,  345 B,  345 C, and  345 D do not overlap with the positions of the other conduction portions  346 . 
     As illustrated in  FIG. 27 , the four electrode pins  345 A,  345 B,  345 C, and  345 D are inserted into the internal space of the complex  344  in a state where the positions of the proximal ends are aligned with each other. The distal end portions of the four electrode pins  345 A,  345 B,  345 C, and  345 D extend to the outside from the distal end of the complex  344  and the conduction portions  346  on the distal end side are exposed to the outside. In the state where the four electrode pins  345 A,  345 B,  345 C, and  345 D are inserted into the internal space of the complex  344 , the positions in the direction along the axis line  350  of the distal ends are different from each other. 
     As illustrated in  FIG. 29 , the four electrode pins  345 A,  345 B,  345 C, and  345 D are disposed so as to be different in the position in the circumferential direction in the internal space of the complex  344 . More specifically, the four electrode pins  345 A,  345 B,  345 C, and  345 D are in a state of being bundled into one. The four electrode pins  345 A,  345 B,  345 C, and  345 D individually abut on the inner surface of the complex  344  and individually abut on the other two electrode pins  345 . Thus, the four electrode pins  345 A,  345 B,  345 C, and  345 D are stably disposed in the internal space of the complex  344 . Although not illustrated in the figure, a columnar shaped core material abutting on each of the four electrode pins  345 A,  345 B,  345 C, and  345 D may be disposed at the center (position of the axis line  350 ) of the complex  344 . 
     As illustrated in  FIG. 29 , the conduction portion  346  on the proximal end side of the third shortest electrode pin  345 C contacts the inner surface of the third electrode ring  337 C and is made electrically conductive by being fixed by soldering or the like in the third electrode ring  337 C from the proximal end in the complex  344 . The outer peripheral surfaces of the other electrode pins  345 A,  345 B, and  345 D are insulation-coated, and thus are insulated although abutting on the third electrode ring  337 C. Thus, the conduction portions  46  on the proximal end side of the four electrode pins  345 A,  345 B,  345 C, and  345 D are electrically connected to the electrode rings  337 A,  337 B,  337 C, and  337 D in one-to-one correspondence. 
     [Method for Manufacturing Guide Wire  330 ] 
     Hereinafter, a method for manufacturing the guide wire  330  and particularly a method for connecting the core wire  331  and the male type connector  339  are described. 
     The four conductive wires  315  extend from the proximal end of the core wire  331  to which the pressure sensor  311  and the like are assembled beforehand. The male type connector  339  is assembled in the state where the four electrode pins  345 A,  345 B,  345 C, and  345 D are inserted into the internal space of the complex  344  and the conduction portions  346  are individually connected to the electrode rings  337 A,  337 B,  337 C, and  337 D. 
     [First Process] 
     As illustrated in  FIG. 30 , an externally fitted state is formed in which the connection tube  336  is externally fitted to the small-diameter portion  342  of the core wire  331 , and then moved to the most distal end side. In the externally fitted state, the connection tube  336  does not project in the direction along the axis line  350  from the proximal end of the small-diameter portion  342  or, even when projecting, slightly projects. Moreover, in the externally fitted state, the four conductive wires  315  extend to the outside from the proximal end portion of the connection tube  336 . In the externally fitted state, the conductive wires  315  and the electrode pins  345  are electrically connected by soldering or the like. The conductive wires  315  can be distinguished from each other by classifying the insulation coats by color, for example. Moreover, the electrode rings  337 A,  337 B,  337 C, and  337 D to which the electrode pins  345  are connected can be distinguished from each other based on the positions of the distal ends projecting from the complex  344 . 
     [Second Process] 
     After the conductive wires  315  and the electrode pins  345  are electrically connected, the connection tube  336  in the externally fitted state is moved so as to project in the direction along the axis line  350  from the small-diameter portion  342  of the core wire  331 . Thus, connection portions between the conductive wires  315  and the conduction portions  346  of the electrode pins  345  are covered with the connection tube  336 , and a proximal end portion of the connection tube  336  contacts the male type connector  339  as illustrated in  FIG. 25 . Then, the connection tube  336  is connected by being fixed to the small-diameter portion  342  of the core wire  331  and the male type connector  339  by an adhesive or the like. 
     [Operational Effects of Fourth Embodiment] 
     According to the guide wire  330 , the conduction portions  346  of the electrode pins  345  project outward from the distal end of the complex  344  even when the male type connector  339  is an assembly article beforehand, and therefore the conduction portions  346  and the conductive wires  315  are easily connected. Moreover, even when a trouble arises in the connection process of the conduction portions  346  and the conductive wires  315 , only the male type connector  339  may be exchanged, and therefore the productivity is good. 
     Moreover, the electrode pins  345  are disposed at the different positions in the circumferential direction in the internal space of the complex  344 , and therefore the strength of the male type connector  339  is held due to the fact that the electrode pins  345  are bundled in the internal space of the complex  344 . 
     Moreover, the conduction portions  346  on the distal side end side of the electrode pins  345  accommodated in the internal space of the complex  344  are different in the position in the direction along the axis line  350 , and therefore the connection relationship between the electrode pins  345  and the electrode rings  337 A,  337 B,  337 C, and  337 D can be easily grasped based on the positions of the conduction portion  346 . 
     Moreover, the electrode pins  345  have the insulation coated outermost surfaces and have the conduction portions  346  in the distal end portions and at the positions individually corresponding to the electrode rings  337 A,  337 B,  337 C, and  337 D to be connected and the conduction portions  346  do not overlap in the direction along the axis line  350  in the male type connector  339 . Therefore, a short circuit between the conduction portions  346  of the electrode pins  345  can be suppressed. 
     Moreover, the connection tube  336  covering the connection portions between the conductive wires  315  and the electrode pins  345  is configured as a separate component from the core wire  331  and the male type connector  339 . Therefore, no member covers the conductive wires  315  and the conduction portions  346  of the electrode pins  345  in the state where the connection tube  336  is not connected to the core wire  331  and the male type connector  339 , and thus an operation of electrically connecting the conductive wires  315  and the conduction portions  346  of the electrode pins  345  is easily performed. 
     Moreover, the small-diameter portion  342  is provided in a distal end portion of the core wire  331  and the connection tube  336  is movable in the direction along the axis line  350  with respect to the small-diameter portion  342 . Therefore, the conductive wires  315  and the conduction portions  346  of the electrode pins  345  are easily exposed to the outside or covered by the movement of the connection tube  336 . Moreover, the outer diameter of the connection tube  336  and the outer diameter on the distal end side relative to the tapered portion  341  of the core wire  331  can be equalized to each other. 
     Moreover, the connection tube  336  is one containing a conductive material and is electrically connected to the core wire  331 , and therefore the core wire  331  can be easily grounded through the connection tube  336 . 
     According to the method for manufacturing the guide wire  330  in the fourth embodiment, the conductive wires  315  and the conduction portions  346  of the electrode pins  345  are connected in the state where the connection tube  336  is not connected to the core wire  331  and the male type connector  339 . Therefore, there is no member covering the conductive wires  315  and the conduction portions  346  of the electrode pins  345 , and thus the workability is good. 
     Moreover, by the movement of the connection tube  336  from the externally fitted state with respect to the small-diameter portion  342  of the core wire  331 , the conductive wires  315  and the conduction portions  346  of the electrode pins  345  are easily exposed to the outside or covered. 
     [Modification of Fourth Embodiment] 
     In the method for manufacturing the guide wire  330  in the fourth embodiment described above, although the connection tube  336  is externally fitted to the small-diameter portion  342  of the core wire  331  in the externally fitted state, a state where the connection tube  336  is externally fitted to the male type connector  339  in place of the small-diameter portion  342  may be an externally fitted state. In the case of the externally fitted state, the inner diameter of the connection tube  336  is almost equal to the outer diameter of the male type connector  339 . After the conductive wires  315  and the conduction portions  346  of the electrode pins  345  are connected, the connection tube  336  in the externally fitted state is moved so as to project in the direction along the axis line  350  from the male type connector  339 . 
     Moreover, in the method for manufacturing the guide wire  330  in the fourth embodiment described above, the conductive wires  315  and the conduction portions  346  of the electrode pins  345  may be connected in a state where the connection tube  336  is not brought into the externally fitted state and is not externally fitted to the guide wire  330  nor the male type connector  339 . Thereafter, the connection tube  336  may be moved to the distal end portion while being externally fitted to a proximal end portion of the male type connector  339 , for example, so that the connection tube  336  may be externally fitted to and connected to the small-diameter portion  342  of the core wire  331  and the male type connector  339 . 
     Moreover, the connection tube  336  is not an indispensable configuration in the guide wire  330  and the guide wire  330  which does not have the connection tube  336  may be configured. For example, the proximal end of the core wire  331  and the male type connector  339  may be directly connected. In that case, the conductive wires  315  extending from the proximal end of the core wire  331  are connected to the conduction portions  346  of the corresponding electrode pins  345 , so that the conductive wires  315  are accommodated in a deflected state in the internal space of the core wire  331 . 
     Moreover, the number of the conductive wires  315 , the number of the electrode rings  337 A,  337 B,  337 C, and  337 D, and the number of the electrode pins  345  in the fourth embodiment described above are merely exemplary and the number of the conductive wires  315 , the number of the electrode rings  337 A,  337 B,  337 C, and  337 D, and the number of the electrode pins  345  may be one or arbitrarily two or more. 
     Moreover, the pressure sensor  311  provided in the guide wire  330  is merely an example of the electronic component and the other sensors measuring the physical quantities (temperature, flow velocity, and the like) of blood or a blood vessel other than the pressure or electronic circuits may be provided. Moreover, the configuration of the distal side end of the guide wire  330  described in the fourth embodiment described above is merely an example. It is a matter of course that the configurations of the spiral body, the tapered pin, the housing, and the like may be altered as appropriate. 
     REFERENCE SIGNS LIST 
     
         
           10  pressure measuring device 
           11  pressure sensor 
           12  sensor body 
           12   a  distal end surface 
           12   b  proximal end surface 
           13  diaphragm 
           14  bridge circuit 
           15  conductive wire 
           16  coating member 
           17  resistor 
           17 A first resistor 
           17 B second resistor 
           18  terminal 
           18 A,  18 C input terminal 
           18 B,  18 D output terminal 
           22  through-hole 
           24  distal electroconductive layer (portion laminated on distal end surface of electroconductive layer) 
           26  connection portion 
           30  guide wire 
           30 A axial direction 
           31  core wire 
           34  housing 
           39  tapered pin 
           110  guide wire system 
           111  pressure sensor 
           130  guide wire 
           130 A axis line 
           135  second spiral body 
           137  contact 
           140  connector 
           141  holding component (example of holding portion) 
           142  connector body 
           143  cable 
           144 ,  244  terminal 
           147  guide component (example of guide portion) 
           148  support component (example of support portion) 
           150  body 
           150   a  insertion hole 
           151  holding piece 
           153  fitting portion 
           165   a  guide surface 
           169  lock portion 
           172 ,  272  terminal portion 
           172   a ,  272   a  contact surface 
           180  body 
           181  converging tube 
         θ angle 
           311  pressure sensor (electronic component) 
           315  conductive wire 
           330  guide wire 
           331  core wire (body) 
           336  connection tube 
           337 A,  337 B,  337 C,  337 D electrode ring 
           339  male type connector 
           341  tapered portion 
           342  small-diameter portion 
           345  electrode pin 
           346  conduction portion