JP4819040B2 - Sensor guide wire assembly - Google Patents

Description

  The present invention relates to a sensor / guidewire assembly in which a physiological sensor in a living body is measured in a blood vessel, and a sensor element is attached to the tip of a guidewire, and more particularly to a sensor element attachment structure. More specifically, the present invention relates to a jacket in which a sensor element is disposed.

  A sensor guide wire assembly in which a sensor is attached to the tip of a guide wire is known. An example of such a sensor guide wire assembly is disclosed in Patent Document 1 which is a patent assigned to the assignee of the present invention. The sensor guide assembly includes a sensor element, an electronic unit, a signal transmission cable connecting the sensor element to the electronic unit, a flexible tube in which the cable and the sensor element are disposed, and a metal wire. And a coil attached to the tip of the metal wire. The sensor element is composed of a pressure sensitive device, for example a thin film on which a piezoresistive element connected in a Wheatstone bridge type array is mounted.

  For example, as disclosed in Patent Document 2 which is also a patent assigned to the assignee of the present invention, the sensor element is disposed inside a short tube (or also called a sleeve or a jacket). The short tube protects the sensor element and provides an opening for the pressure sensitive device to contact the surrounding medium. Further, Patent Document 2 shows a case where the first coil is attached to the front end of the jacket, and the same second coil is attached to the base end of the jacket. A metal wire (usually called a core wire by those skilled in the art) extends from the inside of the jacket, and this metal wire provides a diameter expansion suitable for mounting the sensor element. Yes. The first and second coils are fixed to the respective ends of the jacket by bonding or soldering. Adhesive or solder is also used to fix the jacket and core wire.

  A fundamentally different way of securing the coil to the sleeve, which provides a place for housing the sensor element, is disclosed in US Pat. No. 6,056,097 assigned to Cardiometrics, Inc. In this patent, a spiral groove is formed on the outer surface of the sleeve, and the coil is screwed onto the sleeve surface by the spiral groove. Then, if necessary, the coil is bonded or soldered to the jacket portion of the sleeve.

US Reissue Patent No. 35,648 US Pat. No. 6,167,763 US Pat. No. 5,715,827

  Although it has been found that sensor guidewire assemblies having jackets designed according to the above-described techniques actually work well, the design and mounting functionality of such jackets has been improved, particularly from a manufacturing standpoint. It can be done.

  The sensor guide wire assembly has an essentially rectangular rectangular tip to which a film-like pressure sensitive element made of polysilicon is attached. This sensor chip is arranged inside a jacket, and this jacket similarly accommodates a part of the core wire and at least one electric wire connected to the pressure sensitive element in addition to the sensor chip. . A first coil can be attached to the tip of the jacket, and a second coil can be attached to the proximal end of the jacket. The first and second coils can be attached to each end of the jacket by bonding or soldering. In the prior art, the jacket had an inner diameter and an outer diameter that were uniform over its entire length, but for the purposes of the present invention it should be noted that the inner diameter of the jacket The dimensions and the outer diameter are the same before and after the assembly portion of the sensor guide wire assembly having the jacket as an element.

  What is now clear is that the coil has a spiral shape, so that the contact area between the end face of the jacket and the opposed end faces of the first and second coils is very small. The small contact area means that the corresponding mounting area for the adhesive (or solder) between the jacket and the coil is also small, so that the strength of the connection does not reach the maximum possible strength. It implies that. Another problem is that it is difficult to align the jacket and the first and second coils with respect to smooth transmission between the end of the jacket and the end of the opposing coil. There are cases.

  Moreover, it is now clear that the manufacturing process, including manual bonding to a portion of the core wire of the jacket, is a relatively time consuming technique, and the resulting connection strength will change over time, and One operator and another operator will be different. Similar disadvantages may occur in the corresponding soldering.

  It is an object of the present invention to remedy at least some of the problems caused by prior art jackets.

  The object is achieved by using a jacket having a mechanical attribute that at least one end thereof is externally crimped to the core wire. Reliable fixing is achieved without using an adhesive or solder by one end of the jacket being externally crimped to the core wire. The outer diameter of the end portion of the jacket after the fitting and pressing is preferably adjusted to the inner diameter of the coil so that the coil is fixed to the jacket. Therefore, the coil is fitted into the fitting crimping end of the jacket, and as a result, the contact area between the coil and the jacket is increased. The coil is then preferably glued or soldered to the mating crimp end and the area of the fixed part is increased so that a very reliable bond is achieved.

  A further advantage of the jacket according to the present invention is that the outer diameter of the jacket and the inner diameter of the coil after fitting and crimping are matched, so that the coil and the jacket are automatically aligned with each other, greatly simplifying the manufacturing procedure. And a sensor guide wire assembly that is free of radial protrusions (also caused by non-bonding between the jacket and a coil connected thereto). In order to make the outer surface of the sensor guide wire assembly smooth, the outer diameter of the central portion not involved in the crimping of the jacket must match the outer diameter of the coil. As a result, a circumferential end surface is formed at the end portion of the jacket surface after the jacket is fitted and attached, and this circumferential end surface is the coil at the fitting crimping end. It becomes a natural locking part for stopping the coil after external fitting. This locking portion further simplifies the manufacture of the sensor / guidewire assembly.

  The present invention also relates to an improved method for manufacturing a sensor guidewire assembly having a jacket in which a core wire is housed and at least one end of a coil is secured. According to one aspect of the present invention, the manufacturing procedure includes the steps of passing a core wire through the jacket, applying a first end portion of the jacket, and then a second end portion of the jacket to the core wire. A step of fitting a coil to the first fitting crimping end, and then fitting a second coil to the second fitting crimping end; and the first coil to the first fitting Bonded to the crimping end (or fixed by soldering or other fixing means), and then bonded the second coil to the second mating crimping end (or fixed by soldering or other fixing means) ).

  To better understand the situation in which the present invention is used, FIG. 1 shows a conventional sensor guidewire assembly 1. The sensor guide wire assembly 1 includes a hollow rod 2, a core wire 3, a first coil 4, a second coil 5, a jacket in other words, a sleeve 6, a dome-shaped tip 7, and a sensor element in other words, a sensor chip 8. , And one or a plurality of electric wires 9. The proximal end of the first coil 4 is fixed to the distal end of the hollow rod 2, and the distal end of the first coil is fixed to the proximal end of the jacket 6. The base end of the second coil 5 is connected to the tip of the jacket 6, and the dome-shaped tip 7 is attached to the tip of the second coil. At least a part of the core wire 3 is disposed in the hollow rod 2, and a tip portion of the core wire 3 extends out of the hollow rod 2 and is inserted into the second coil 5. The sensor element 8 is attached to the core wire 3 in the jacket 6 and is connected to an electronic unit (not shown) through the electric wire 9. The sensor element 8 has a film-like pressure-sensitive device (not shown in the figure), and contacts a medium such as blood surrounding the tip of the sensor guide wire assembly 1 through the opening 10 of the jacket 6. .

  In FIG. 1, it should be noted that the jacket 6 has a uniform tubular shape, and the first and second coils 4 and 5 are merely in contact with each end of the jacket 6. is there. Knowing that the typical diameter of the sensor guidewire assembly 1 is only 0.35 mm, geometrically possible between the end of the jacket and the end of the coil that touches it. You notice that the contact area is very small. And the actual contact area becomes smaller. This is because the coil has a helical shape, so that in practice, a smaller part of the end of the coil will come into contact with the end of the jacket. Normally, the coil is connected to the end of the jacket by bonding or soldering, but the strength of this connection is far inferior to its maximum possible strength for the reasons described above.

  The assembly of a sensor guidewire assembly such as that shown in FIG. 1 is basically manual. Thus, it can be seen that the tubular coil has no means for positioning the coil on the jacket. This means that there may be a radial step from the coil to the jacket after assembly, in other words, the surface of the sensor guidewire assembly is not smooth enough ( , Which is unfavorable).

  FIG. 2 shows a cross-sectional structure of the sensor guide wire assembly 21 according to the present invention. The sensor / guidewire assembly 21 includes a core wire 22 and a first (in other words, proximal end) coil 23, and the first coil 23 is fixed to a proximal end of a jacket (in other words, a sleeve) 24. A second (in other words, tip) coil 25 is fixed to the tip of the jacket 24, and the core wire 22 penetrates and extends through the second coil 25. The sensor / guidewire assembly 21 further includes a sensor element (in other words, a sensor chip) 26. The sensor element 26 is attached to the core wire 22 in the jacket 24, and one sensor element 26 is provided. Alternatively, it is connected to an electronic unit (not shown) via a plurality of electric wires (not shown). The sensor element 26 has a film-like (not visible) pressure-sensitive device, and is a medium such as blood that covers the illustrated portion of the sensor guide wire assembly 21 through the opening 27 of the jacket 24. To touch.

  Compared to the jacket 6 shown in FIG. 1, the jacket 24 shown in FIG. 2 is not uniform in shape along the length direction, but has a first end portion, ie, a base end portion 24 a, The end portion 24b has a distal end portion 24b and a central portion 24c. The end portions 24a and 24b are reduced in diameter as compared with the central portion 24c, and the outer diameter of the central portion 24c is the first and second coils 23, 25 is almost the same. The first and second end portions 24a and 24b of the jacket 24 are externally fitted to the core wire 22. Therefore, in this portion, the inner diameter of one end portion 24a (or 24b) and the diameter of the core wire 22 are set. Are the same. If the core wire 22 has a different diameter outside the central portion 24c, the first and second end portions 24a and 24b may have different diameters. By fast fitting and crimping the end portion of the jacket to the core wire, it is possible to provide a quick and reliable fixing method for fixing the jacket to the core wire. A suitable pliers can be used for this fitting crimping. As a special structure of the sensor guide wire assembly, only one end portion of the jacket may be externally fitted to the core wire, and the other end portion may be fixed by a conventional technique such as adhesion or soldering.

  As shown in FIG. 2, after crimping, the diameter of the base end portion 24a of the jacket 24 is basically the same as the inner diameter of the base end coil 23, and the diameter of the front end portion 24b is the inner diameter of the front end coil 25. Is basically the same. In assembling the sensor guide wire assembly 21, the proximal coil 23 is fitted onto the proximal part 24a, and the distal coil 25 is fitted onto the distal part 24b. Accordingly, the outer crimping portion of the jacket serves as a guide portion, facilitates assembly of the sensor guide wire assembly, and ensures positioning and centering of the coil with respect to the jacket. Compared to prior art sensor guidewire assemblies, the present invention provides a larger contact area between the coil and the jacket and makes the connection between the two elements more reliable. The difference is that it provides a jacket with a crimped end portion. What should be emphasized here is that even if the outer diameter of the crimping end portion does not completely match the inner diameter of the connecting coil, the narrow portion from the central portion of the jacket to the crimping portion is It is always to provide a contact area that is larger than the contact area when the coil (as shown in FIG. 1) is connected to the very end face of the jacket. The requirement to match the diameter of the crimped end portion with the inner diameter of the connecting coils is therefore not essential in the practice of the invention. Furthermore, when the outer diameter of the crimping end portion is only slightly smaller than the inner diameter of the coil connected thereto, the gap between the two elements may be filled with a fixing agent such as an adhesive or solder. .

  As can be understood from the foregoing, the method for assembling the sensor guide wire assembly includes the following steps. That is, (a) a step of arranging a jacket on the core wire and fitting and crimping the first end portion of the jacket to the core wire; and (a ′) fitting and crimping the second end portion of the jacket to the core wire. (B) a step of fitting a part of the first coil to the first crimping end portion of the jacket, and (b ′) fitting a second coil to the second crimping end portion of the jacket. (C) adhering (or soldering or otherwise fixing) a part of the first coil to the first crimping end portion of the jacket on which the coil is fitted; and c ′) a step of adhering (or soldering or otherwise fixing) a part of the second coil to the second crimping end portion of the jacket on which the coil is fitted. Steps (a '), (b') and (c ') are optional steps and can be omitted without departing from the scope of the present invention.

  In the embodiment disclosed in FIG. 2, the core wire 22 is expanded in diameter at the position where the sensor chip 26 is attached. That is, the sensor chip 26 is mounted in the recess of the diameter-enlarged portion of the core wire. The base end portion 24a of the jacket 24 is externally fitted and crimped to the base end of the enlarged portion of the core wire, and the distal end portion 24b is fitted and crimped to the distal end of the enlarged portion of the core wire. In other words, the proximal and distal end portions 24a, b are crimped from a relatively large diameter to a relatively small diameter. If the jacket is excessively crimped, the strength of the jacket may be reduced, and two different embodiments of the present invention for solving the problem caused by such load force are shown in FIGS. 3 and 4, respectively.

  FIG. 3 shows a cross-sectional configuration of the main part of the sensor guide wire assembly 31 according to the present invention. The sensor guide wire assembly 31 includes a core wire 32 and a first (in other words, proximal end) coil 33, and the first coil 33 is fixed to a proximal end of a jacket (in other words, a sleeve) 34. The front end of the jacket 34 is fixed to a second (in other words, front end) coil 35, and the core wire 32 extends through the second coil 35. The sensor guide wire assembly 31 further includes a sensor element (in other words, a sensor chip) 36. The sensor element 36 is attached to the core wire 32 in the jacket 34, and one sensor element 36 is provided. Alternatively, it is connected to an electronic unit (not shown) via a plurality of electric wires (not shown). The sensor element 36 has a film-like (not shown) pressure-sensitive device, and is a medium such as blood that covers the illustrated portion of the sensor guide wire assembly 31 through the opening 37 of the jacket 34. To touch. As shown in FIG. 3, the core wire 32 has an enlarged diameter portion at a position where the sensor element 36 is attached. The jacket 34 has a first end portion or base end portion 34a, and a second end portion or front end portion 34b. Compared to the first embodiment shown in FIG. 2, the first and second end portions 34 a and b are externally fitted and pressure-bonded to a part of the enlarged diameter portion of the core wire 32. By externally crimping the jacket 34 to the enlarged diameter portion of the core wire 32, the actual crimping force of the jacket 34 is minimized, and at the same time, distortion generated in the material of the jacket 34 is greatly reduced to a minimum. The However, a possible disadvantage of this attachment technique is that the crimped end portion 34a (or 34b) of the jacket 34 cannot constitute a guide portion for guiding and securing the coil.

  FIG. 4 shows a third embodiment of the sensor guide wire assembly 41 according to the present invention. The sensor / guidewire assembly 41 includes a core wire 42 and a first (in other words, proximal end) coil 43, and the first coil 43 is fixed to a proximal end of a jacket (in other words, a sleeve) 44. The front end of the jacket 44 is fixed to a second (in other words, front end) coil 45, and the core wire 42 penetrates and extends through the second coil 45. The sensor / guidewire assembly 41 further includes a sensor element (in other words, a sensor chip) 46, and this sensor element 46 is attached to the core wire 42 in the jacket 44. Alternatively, it is connected to an electronic unit (not shown) via a plurality of electric wires (not shown). The sensor element 46 has a film-like (not visible) pressure-sensitive device, and is a medium such as blood that covers the illustrated portion of the sensor guide wire assembly 41 through the opening 47 of the jacket 44. To touch. Similar to the previous embodiment shown in FIGS. 2 and 3, the sensor element 46 is attached to the central portion 42c of the core wire 42 having an enlarged diameter portion. As shown in FIG. 4, compared to the previous embodiment, the core wire 42 similarly has a proximal end portion 42a and a distal end portion 42b. These proximal and distal ends 42a, b each have a diameter that is smaller than the diameter of the central portion 42c, but these diameters are larger than the diameter of the remaining portion of the core wire 42. The diameter of the proximal end portion 42a may or may not be the same as the diameter of the distal end portion 42b. The jacket 44 has a first end or base end portion 44a and a second end or top end portion 44b. As shown in FIG. 4, the base end portion 44 a is externally crimped to the base end portion 42 a of the core wire 42, and the distal end portion 44 b is externally crimped to the distal end portion 42 b of the core wire 42. This third embodiment of the present invention is a combination of the first and second embodiments described above, and the crimping proximal end portion and the crimping distal end portions 44a and 44b of the jacket 44 lead each coil. It serves as a guide portion for fixing, and the diameters of the proximal end and the distal end portions 42a and 42b of the core wire 42 are larger than the corresponding portions of the core wire in the previous embodiment. For this reason, the diameters of the base end and the tip end portions 44a and 44b of the jacket 44 are further reduced by the external fitting pressure bonding.

  The fitting crimping technique according to the present invention may be applied only to one side of the jacket. That is, the base end (or front end) part of the jacket is fitted and crimped, and the other front end (or base end) part is placed without fitting and crimped, or is attached to the core wire by conventional means such as adhesion or soldering. It may be fixed. Similarly, a sensor guidewire assembly may be designed by combining two of the three embodiments described above. That is, the proximal end portion of the jacket may be fitted and crimped according to one embodiment, and the distal end portion of the jacket may be fitted and crimped based on one of the remaining two embodiments.

  According to the present invention, the jacket adapted for fitting and crimping may have different thicknesses along its length direction. For example, the thickness of the proximal end or the distal end portion may be reduced as compared with the thickness of the central portion. Specifically, at least one portion of the jacket material may have a yield point lower than the yield point of the core wire material. Here, the most interesting part is the fitting crimping part of the jacket, the part where the jacket of the core wire is fitted and crimped, and the part where the jacket and the core wire are in contact with each other. Also, it is important to note that the jacket may be crimped by different methods. That is, in detail, the jacket may not be uniformly crimped to the periphery thereof, but instead may be crimped only to a part of the outer periphery thereof. For example, this is the case when the non-uniformly crimped jacket portion has a D-shaped cross section. Furthermore, a more localized crimping technique may be used. If the jacket is crimped non-uniformly as described above, the core wire will be placed in an off-center position within the jacket, and may still be.

  Although the present invention has been described with reference to particular embodiments and with reference to the accompanying drawings, those skilled in the art will recognize many variations within the scope of the present invention as defined by the specification and the claims. It is clear that changes can be made. Of particular note is that the improved characteristics of a sensor guidewire assembly having a jacket according to the present invention are not dependent on the design of the remaining parts of the sensor guidewire assembly. . For example, the core wire to which the jacket is fixed may extend over the entire length of the sensor / guide wire assembly, or may be provided only at the tip of the sensor / guide wire assembly.

1 schematically illustrates the general structure of a sensor guidewire assembly according to the prior art. FIG. FIG. 2 schematically illustrates a portion of a sensor guidewire assembly having a jacket according to the present invention. 1 shows a first embodiment of a sensor guidewire assembly with a jacket according to the present invention. FIG. FIG. 6 shows a second embodiment of a sensor guidewire assembly with a jacket according to the present invention.

Explanation of symbols

22, 32, 42 Core wire 23, 33, 43 First coil 24, 34, 44 Jacket 24a, 34a, 44a Jacket first end portion 24b, 34b, 44b Jacket second end portion 26, 36, 46 Sensor chip

Claims (10)

A sensor guidewire assembly for measuring at least one physiological change in a living body in a blood vessel,
And the core wire (22, 32 and 42),
Comprises a jacket first coil attached to the first end portion of the (24, 34, 44) (23, 33),
The jacket (24, 34, 44) externally fits a part of the core wire (22, 32, 42) and accommodates at least a part of the sensor chips (26, 36, 46).
Said first end portion (24a, 34a, 44a) is a sensor and guide wire assembly, characterized in that it is fitted crimped to the core wire. The sensor guidewire assembly according to claim 1, wherein a part of the first coil is fitted on the first end portion.   2. The sensor guide wire according to claim 1, wherein the material of the first end portion has a lower yield point than the material of the portion of the core wire that is fitted and crimped to the first end portion. ·assembly. The jacket further includes a second coil (25, 35, 45), the jacket further includes a second end portion (24b, 34b, 44b), and the second end portion is externally crimped to the core wire. 2. The sensor guide wire assembly according to claim 1, wherein the second coil is externally fitted to the external fitting crimp portion.   5. The sensor guide wire according to claim 4, wherein the material of the second end portion has a lower yield point than the material of the portion of the core wire that is fitted and crimped to the second end portion. ·assembly. 3. The sensor guide wire assembly according to claim 2 , wherein the first fitting crimping end portion of the jacket has an outer diameter suitable for attaching the outer fitting portion of the first coil. .   5. The sensor guide wire according to claim 4, wherein the second end portion of the jacket which is fitted and crimped has an outer diameter suitable for attaching the outer fitting portion of the second coil. ·assembly. A method of manufacturing a sensor guidewire assembly for measuring at least one physiological change in a living body in a blood vessel, comprising:
(A) placing the jacket (24, 34, 44) on the core wire (22, 32, 42), and externally crimping the first end portion (24a, 34a, 44a) of the jacket to the core wire;
(B) the first part of Ru step of attaching the coil to the first crimp end portion of the jacket,
(C) A method of manufacturing a sensor guide wire assembly, comprising a step of bonding or soldering a part of the first coil to a first crimping end portion of the jacket. 9. The sensor guide wire assembly manufacturing method according to claim 8, wherein the step (b) includes a step in which a part of the first coil crimps the first end portion of the jacket. Method. And (a ′) a step of externally crimping the second end portion of the jacket to the core wire,
(B ′) a step of externally fitting a second coil to a second crimping end portion of the jacket; and (c ′) a second of the jacket in which a part of the second coil is externally fitted by the coil. 10. The method of manufacturing a sensor guide wire assembly according to claim 8, further comprising a step of bonding or soldering to the crimping end portion of the sensor.

Images