JP2017156085A - Pressure-sensitive sensor module, guide wire for measuring pressure, and pressure measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure measuring device that measures pressures of papilla constrictor and the like with a guide wire for measuring pressure equipped with a pressure-sensitive sensor module.SOLUTION: In a pressure measuring device, a pressure-sensitive sensor module 200 so holds the two ends of each of paired strain sensors 220 and 230 in parallel to and opposing each other, each having a strain gauge on a rectangular base plate on the circumferential face of a hollow pipe-shaped frame 210 having a through-hole in the lengthwise direction. A guide wire 100 is passed through the through-hole in the frame 210 of this pressure-sensitive sensor module 200 and fixed in a random position. A measurement calculating device 300 measures pressure by converting the resistance components arising in the strain gauge of each of the paired strain sensors 220 and 230 into voltages and synthesized the converted voltages.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a pressure-sensitive sensor module, a pressure measurement guide wire, and a pressure measurement device that are applied to, for example, an endoscope guide wire.

  In the medical field, for example, for endoscopic diagnosis of dysfunction in the duodenal papillary sphincter (hereinafter referred to as SOD), a 4Fr. (Φ1.35mm) to 8Fr. (Φ2.7mm) catheter is inserted into the bile duct and pancreatic duct. To measure the pressure. However, since there is no simple, safe and practical pressure measurement catheter that can be used for endoscopic diagnosis of SOD, the incidence of pancreatitis after the examination is high, and it is not common.

  On the other hand, when a SOD pressure measurement was performed under endoscopic retrograde cholangiopancreatography (ERCP) using a coronary pressure measurement guidewire (see Non-Patent Document 1), good results were obtained. There is a report. The coronary pressure measurement guidewire is φ0.035 inch (φ0.89 mm), and it was found that this diameter is effective.

  However, the pressure-sensitive sensor module used for measuring the pressure in the coronary arteries only measures the internal pressure of blood in the coronary arteries, and is not structurally suitable for measuring muscle strength like the papillary sphincter. Therefore, a pressure-sensitive sensor module that can be used for SOD diagnosis by entering the diameter of the guide wire of the coronary artery and a pressure measuring device that can measure pressure with high accuracy from the sensor output are desired.

"Functional evaluation of coronary artery stenosis using pressure wire", Hitoshi Matsuo, Sachiro Watanabe, Coronary Disease Journal 2006, 12: 128-134

  The present embodiment is intended to provide a pressure-sensitive sensor module, a pressure measuring guide wire, and a pressure measuring device that are small and suitable for measuring muscle strength such as a papillary sphincter.

  The pressure-sensitive sensor module of the present embodiment is a pair of strain sensors each formed by forming a strain gauge on a rectangular substrate and a hollow pipe formed by forming a through hole in the longitudinal direction, and the pair of sensors on the peripheral surface. A frame that holds both ends of the strain sensor in parallel and opposite to each other in the longitudinal direction, and the frame has a guide wire inserted through the through hole and is positioned at an arbitrary position of the guide wire. It is fixed.

  The pressure measurement guide wire of the present embodiment includes a pair of strain sensors each having a strain gauge formed on a rectangular substrate on the peripheral surface of a hollow pipe-shaped frame formed with a through hole in the longitudinal direction. A pressure-sensitive sensor module that holds both ends of the pressure-sensitive sensor module parallel to the longitudinal direction and facing each other is inserted into the through-hole of the frame, and the pressure-sensitive sensor module is fixed at an arbitrary position. Yes.

  The pressure measuring device according to the present embodiment includes a pair of strain sensors each having a strain gauge formed on a rectangular substrate on the peripheral surface of a hollow pipe-shaped frame formed with through holes in the longitudinal direction. The pressure measurement sensor module includes pressure-sensitive sensor modules that hold both ends of the frame in parallel with each other, and is inserted into the through-hole of the frame, and the pressure-sensitive sensor module is fixed at an arbitrary position. And a measurement calculation means for measuring the pressure by converting the resistance components generated in the strain gauges of the pair of strain sensors into voltage values and combining them.

The perspective view which shows schematic structure of the pressure measuring device which concerns on 1st Embodiment. The disassembled perspective view which shows the structure of the pressure sensitive sensor module shown in FIG. The top view which shows the structure of the distortion sensor shown in FIG. The top view which shows the structure of the flame | frame shown in FIG. 2, a front view, and a side view. The block diagram which shows the structure of the measurement calculating apparatus shown in FIG. FIG. 6 is a circuit diagram showing a configuration of a bridge circuit of the measurement arithmetic device shown in FIG. 5. The figure for demonstrating the pressure measurement calculation process of the measurement calculation apparatus shown in FIG. The perspective view which shows schematic structure of the pressure measuring device which concerns on 2nd Embodiment. FIG. 9 is an overall view and an exploded perspective view showing the structure of the pressure-sensitive sensor module shown in FIG. 8.

  Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  1A is a plan view showing a schematic configuration of the pressure measuring device according to the first embodiment, and FIG. 1B is an enlarged perspective view showing a pressure-sensitive sensor module portion of FIG. In FIG. 1, the pressure measurement device attaches a pressure-sensitive sensor module 200 to a predetermined position from the tip of the guide wire 100, and connects a lead wire drawn from the pressure-sensitive sensor module 200 to the measurement arithmetic device 300. Then, the measurement arithmetic device 300 calculates the pressure at the sensor installation point from the strain detection output of the pressure-sensitive sensor module 200. A coil 800 (Pt, Au) is wound around the guide wire 100, and a hydrophilic coating is applied thereon.

  FIG. 2 is an exploded perspective view showing the structure of the pressure-sensitive sensor module 200 shown in FIG. In FIG. 2, reference numeral 210 denotes a frame through which the guide wire 100 is inserted and fixed at a predetermined position from the tip thereof. The frame 210 has a hollow pipe shape, and a first strain sensor 220 and a second strain sensor 230 are arranged opposite to each other in parallel on the peripheral surface thereof.

  FIG. 3 is a plan view showing a specific configuration of the first and second strain sensors 220 and 230. Since the second strain sensor 230 has the same configuration as the first strain sensor 220, the configuration will be described using the first strain sensor 220 here. In addition, the code | symbol in parenthesis has shown the code | symbol of the 2nd distortion sensor 230. FIG.

  In the first strain sensor 220 (230) shown in FIG. 3, the substrate 221 (231) has, for example, a rectangular shape, and is made of, for example, a ceramic substrate, a metal substrate coated with an insulating film, or a glass substrate. The substrate 221 (231) needs to be rigid in the width direction and displaceable in the thickness direction.

  As the ceramic substrate, for example, zirconia, aluminum oxide, or aluminum nitride is applicable. The ceramic substrate itself has an insulating property, and in particular, zirconia is a material strong against brittle fracture. Therefore, in this embodiment, it is desirable to use zirconia as the substrate 221 (230).

  As the metal substrate on which the insulating film is applied, for example, iron or stainless steel is applicable. As the insulating film, for example, silicate glass, aluminum oxide, aluminum nitride, polyimide, or the like is applicable. A metal substrate coated with an insulating film has a feature that the metal substrate itself as a base material is a material strong against brittle fracture.

  As the glass substrate, heat-resistant tempered glass such as Pyrex (registered trademark), Tempax (registered trademark), or the like is applicable. The glass substrate is characterized in that the substrate itself has insulating properties and is inexpensive.

  On one surface of the substrate 221 (231), a strain gauge 222 (232) as a strain sensitive resistance film is formed, for example, by a thin film pattern, for example, at a substantially central portion in the longitudinal direction.

  The strain gauge 222 (232) functions as a strain sensitive resistance film having a high gauge factor, for example, on the substrate 221 (231), and a metal material or a semiconductor material is formed by using, for example, sputtering and etching. It is. The strain gauge 222 (232) is intended to improve sensitivity by diffracting the thin film pattern a plurality of times in a direction orthogonal to the longitudinal direction of the substrate 221 (231).

  Electrode pads 223 and 224 (233 and 234) are arranged on both ends of the substrate 221 (231), and both ends of the strain gauge 222 (232) are arranged on the electrode pads 223 and 224 (233 and 234) by pattern wiring. It is connected to the. The electrode pads 223 and 224 (233 and 234) are connected to the end portions of the lead wires 225 and 226 (235 and 236) along the longitudinal direction, for example, by soldering. The lead wire 225 (235) is pulled out in the same direction as the lead wire 226 (236) is pulled out, traces the guide wire 100, and is connected to the signal input terminal of the measurement arithmetic device 300.

  The formation position of the strain gauge 222 (232) is not limited to the central portion of the substrate 221 (231), but may be arranged near the end of the substrate 221 (231). In other words, it may be a position where stress is sufficiently applied to the strain gauge 222 (232) due to the deformation of the substrate 221 (231).

  FIG. 4 shows a specific configuration of the frame 210 shown in FIG. 2, wherein (a) is a plan view, (b) is a front view, and (c) is a side view. The frame 210 includes a first substrate housing portion 211 that houses the first strain sensor 220 and the second strain sensor 230 in parallel with each other in the longitudinal direction so that the front surface or the back surface is opposed to each other. A second substrate housing part 212 is provided.

  The first substrate accommodating portion 211 is a shelf that supports both ends of the substrate 221 and floats the central portion of the substrate so that the substrate 221 bends inward when pressure is applied to the accommodated substrate 221. Sections 211a and 211b. Similarly, the second substrate housing portion 212 includes shelves 212a and 212b.

  The frame 210 is formed with guide grooves 211c and 211d for guiding the lead wires 225 and 226 of the first strain sensor 220 in the longitudinal direction from both ends of the first substrate housing 211, and the second substrate. Guide grooves 212c and 212d for guiding the lead wires 235 and 236 of the second strain sensor 230 in the longitudinal direction from both ends of the housing portion 212 are formed. Further, a step 213 for guiding the lead wires 225 and 235 guided by the guide grooves 211c and 212c along the peripheral surface is formed around one end surface of the frame 210. Guide grooves 214 and 215 are formed for guiding the lead wires 225 and 235 guided by the step 213 on the end surface to the other surface side of the other. Thereby, the lead wires 225, 226, 235, 236 of the first and second strain sensors 220, 230 accommodated in the first and second substrate accommodating portions 211, 212 are both pulled out from one end of the frame 210, The measurement arithmetic device 300 can be connected along the guide wire 100.

  FIG. 5 is a block diagram showing a configuration of the measurement arithmetic device 300 shown in FIG. In FIG. 5, the measurement calculation device 300 includes first and second bridge circuits 310 and 320, an A / D (analog / digital) conversion unit 330, a calculation unit 340, and a display unit 350.

  The first bridge circuit 310 and the second bridge circuit 320 connect the first and second strain sensors 220 and 230 as resistances to be measured, respectively, and change resistance values corresponding to the amount of strain applied to the sensors. Detect as voltage value.

  FIG. 6 shows an example of the first and second bridge circuits 310 and 320. Since the first and second bridge circuits 310 and 320 are the same circuit, only the first bridge circuit 310 will be described.

  The first bridge circuit 310 shown in FIG. 6 is a so-called Wheatstone bridge circuit. Since the operating principle of the Wheatstone bridge circuit is well known, description thereof is omitted. In this bridge circuit 310, a first strain sensor (resistance value Rg) 220 and a resistor 311 are connected in series between the power supply terminal V and the ground, and further, resistors 312 and 313 are connected in series between the power supply terminal V and the ground. Yes. These resistors 311, 312, and 313 are temperature compensated resistors, and their resistance values are set to “R”. The voltage Vout is output from the potential difference between the connection node between the first strain sensor 220 and the resistor 311 and the connection node between the resistors 312 and 313. When stress is applied to the first strain sensor 220, the resistance value Rg of the first strain sensor 220 changes and the output voltage Vout changes.

  The second bridge circuit 320 is connected to a second strain sensor 230 instead of the first strain sensor 220 shown in FIG.

  In FIG. 5, output voltages Vx1 and Vx2 of the first and second bridge circuits 310 and 320 are digitized by an analog / digital (A / D) conversion unit 330 and then supplied to the calculation unit 340. The calculation unit 340 calculates a pressure value applied to the pressure-sensitive sensor 200 based on the digitized output voltages of the first and second bridge circuits 310 and 320 supplied from the A / D conversion unit 330. The calculation result is displayed on the display unit 350.

  The calculation of the pressure value of the calculation unit 340 will be described with reference to FIG.

First, as shown in FIG. 7A, the length between the longitudinal fulcrums of the substrates 221 and 231 of the first and second strain sensors 220 and 230 is L, the width is W, and the thickness is h. The positions of the sensors 222 and 232 are Ls, the position where the load P is applied at the center of the substrate is L / 2, and the displacement in the normal state is δ. As an example, L = 8.0 mm, W = 0.4 mm, h = 0.1 mm, Ls = 3.0 mm, P = 0.53N (≈5.4 gf), and δ = about 0.1 mm. When calculating the surface strain ε at this time (bending at three points at both ends and the center),
ε = −702.7 × 10 ⁻⁶
It becomes.

Now, as shown in FIG. 7B, when a load P is applied as pressure to the center of the sensor, the thin film gauge factor is Kg, the bridge supply voltage is V,
Kg ≒ 12, V = 5.0V
Then, the strain detection voltage Vout generated in each strain sensor 220, 230 is
Vout = (1/4) × Kg × V × ε ≒ −10.5mV
It becomes. In this case, since the output voltages of the strain sensors 220 and 230 are both of the same polarity, the output voltage is approximately doubled by combining the two, and it is possible to measure with higher accuracy.

  On the other hand, when the load P is applied as a bending stress to the sensor end as shown in FIG. 7C under the above conditions, the strain detection voltages Vout generated in the first and second strain sensors 220 and 230 are the same. It becomes voltage, but the polarity is reversed. For this reason, by combining the two, the bending stress component is canceled and does not affect the measurement of the pressure.

  As described above, the pressure-sensitive sensor module 200 according to the first embodiment can be realized as a size that can be incorporated into φ0.035 inch (φ0.89 mm) that can be attached to the guidewire 100 for measuring the papillary sphincter. .

  In particular, since the pressure-sensitive sensor module 200 has a hollow pipe structure that allows the core wire of the guide wire 100 to pass therethrough, the pressure-sensitive sensor module 200 can be easily manufactured separately from the guide wire 100. Assembly can be facilitated.

  Further, since two strain sensors 220 and 230 are attached to the frame 210 so that the front surface or the back surface are opposed to each other, the bending force acting on the pressure-sensitive sensor module 200 is canceled in the measurement arithmetic device 300, and the papillary sphincter Only the tightening force can be measured, and the pressure can be measured with higher accuracy.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS.

  8A is a perspective view showing a schematic configuration of a pressure measuring device according to the second embodiment, and FIG. 8B is an enlarged perspective view showing a pressure-sensitive sensor module portion of FIG. The pressure measurement device shown in FIG. 8 includes an insertion guide 700, a pressure sensor module 500, and a measurement calculation device 600. Since the measurement arithmetic device 600 is the same as the measurement arithmetic device 300 of the first embodiment, description thereof is omitted here.

  A pressure-sensitive sensor module 500 is attached to the distal end portion of the guide wire 401 drawn from the measurement arithmetic device 600 via an elastic deformation coupling portion 501, and another pressure-sensitive sensor module 500 is attached to the other end portion. A distal end core shaft 702 that is elastically deformable and narrows toward the distal end is attached via an elastic deformation coupling portion 502, and a coil (not shown) is wound around the distal end, and a hydrophilic coating is formed thereon. It has been subjected. The coil is the same as the coil 800 shown in FIG. 1 of the first embodiment. A lead wire (not shown) drawn from the pressure-sensitive sensor module 500 is connected to the measurement arithmetic device 600. Then, the measurement calculation device 600 calculates the pressure at the sensor installation point from the strain detection output of the pressure-sensitive sensor module 500.

  FIGS. 9A and 9B are an overall perspective view and an exploded perspective view showing the structure of the pressure-sensitive sensor module 500 shown in FIG. In FIG. 9, reference numeral 510 denotes a frame whose both ends are coupled to the end portion of the non-insertion side guide wire 401, the end portion of the distal end core shaft 702, and the elastic deformation members 501 and 502. The frame 510 has a columnar shape, and is held in a state where the first strain sensor 520 and the second strain sensor 530 are arranged in parallel on the circumferential surface so that the front surface or the back surface is opposed to each other.

  The strain sensors 520 and 530 have the same configuration as the strain sensors 220 and 230 of the first embodiment shown in FIG. Therefore, description of the strain sensor itself is omitted here. Also, since the lead wire has the same configuration as the strain sensors 220 and 230 of the first embodiment, the description and illustration of the formation of the wiring path in the frame 510 and the like are omitted.

  The frame 510 includes a first substrate housing portion 511 and a first substrate housing portion 511 for housing the first strain sensor 520 and the second strain sensor 530 in parallel along the longitudinal direction so that the front surface or the back surface is opposed to each other. 2 substrate housings (not shown).

  When the pressure is applied to the substrate of the stored strain sensor 520, the first substrate housing portion 511 supports the both end portions of the substrate and floats the central portion of the substrate so that the substrate bends inward. Shelves 511a and 511b. Similarly, the second substrate housing portion also includes a shelf portion.

  That is, in the pressure measuring device having the above-described configuration, the pressure-sensitive sensor module 500 is provided in the vicinity of the distal end portion of the guide wire 401 via the elastic deformation coupling portion 501, and elastic deformation is performed from the module 500 via the elastic deformation coupling portion 502. Since the tip core shaft 702 having a shape that can be narrowed toward the tip is extended and the tip chip coil 703 is attached to the tip, the pressure sensor part can be easily inserted to the affected part such as the sphincter sphincter. Can do.

  Further, in the pressure-sensitive sensor module 500, the pair of strain sensors 520 and 530 are held in a substantially parallel state so that the front and back surfaces thereof face each other, so that the measurement arithmetic device 600 is the same as in the first embodiment. In this case, the bending force acting on the pressure-sensitive sensor module 500 can be canceled and only the tightening force of the nipple sphincter can be measured, and the pressure can be measured with higher accuracy.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 100, 401 ... Guide wire, 200, 500 ... Pressure-sensitive sensor module, 210, 510 ... Frame, 211, 511 ... 1st board | substrate accommodation part, 212 ... 2nd board | substrate accommodation part, 211a, 211b, 212a, 212b, 511a, 511b ... shelf, 211c, 211d, 212c, 212d, 214, 215 ... guide groove, 213 ... step, 220, 520 ... first strain sensor, 221 ... substrate, 222 ... strain gauge, 223, 224 ... electrode Pads, 225, 226 ... lead wires, 230 ... second strain sensor, 231 ... substrate, 232 ... strain gauge, 233, 234 ... electrode pads, 235, 236 ... lead wires, 300 ... measurement arithmetic unit, 310 ... first Bridge circuit, 311, 312, 313 ... resistor, 320 ... second bridge circuit, 330 ... A / D (analog) / Digital) conversion unit 340 ... arithmetic unit, 350 ... display unit, 700 ... insertion guide portion, 702 ... tip core shaft, 703 ... tip coil

Claims (8)

A pair of strain sensors each formed by forming a strain gauge on a rectangular substrate;
A frame formed on the peripheral surface with a pair of accommodating portions that hold both ends of the pair of strain sensors in parallel with each other along the longitudinal direction and with the front or back surfaces facing each other;
The frame is a pressure-sensitive sensor module fixed to an arbitrary position of a guide wire.   2. The pressure sensitive device according to claim 1, wherein the frame has a hollow pipe shape in which a through hole is formed in a longitudinal direction, and is fixed to an arbitrary position of the guide wire in a state where the guide wire is inserted into the through hole. Sensor module. The frame is columnar,
The pressure-sensitive sensor module according to claim 1, wherein an elastic deformation coupling portion is provided at both ends of the frame so as to be elastically deformable with the guide wire.   A pair of strain sensors each formed by forming a strain gauge on a rectangular substrate is housed in a pair of housing portions formed on the peripheral surface of the frame, and the pair of strain sensors are parallel to the longitudinal direction on the surface. Alternatively, a pressure-measuring guide wire in which a pressure-sensitive sensor module in which both ends are held with the back surfaces facing each other is arranged at an arbitrary position on the guide wire.   The pressure according to claim 4, wherein the frame has a hollow pipe shape in which a through hole is formed in a longitudinal direction, and is fixed to an arbitrary position of the guide wire in a state where the guide wire is inserted into the through hole. Guide wire for measurement. The frame is columnar,
The pressure measurement guide wire according to claim 4, wherein an elastic deformation coupling portion is provided at both ends of the frame so as to be elastically deformable with the guide wire. A pair of strain sensors each formed by forming a strain gauge on a rectangular substrate is housed in a pair of housing portions formed on the peripheral surface of the frame, and the pair of strain sensors are parallel to the longitudinal direction on the surface. Alternatively, a pressure-measuring guide wire in which a pressure-sensitive sensor module in which both ends are held in a state where the back surfaces face each other is arranged at an arbitrary position of the guide wire, and
A pressure measurement apparatus comprising: a measurement calculation unit that measures a pressure by converting a resistance component generated in a strain gauge of each of the pair of strain sensors into a voltage value and combining them. The measurement calculation means includes
A pair of bridge circuits that connect the pair of strain sensors as resistances to be measured and detect a change in resistance value corresponding to the amount of strain applied to each sensor as a voltage value;
The pressure measuring apparatus according to claim 7, further comprising a combining unit that combines the output voltages of the pair of bridge circuits based on respective polarities.

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