Foreign body-recovering instrument for endoscope

[0002] The present disclosure relates to subject matter contained in Japanese Patent Application No. 10-164651 (filed on Jun. 12, 1998), which is expressly incorporated herein by reference in its entirety.

[0003] 1. Field of the Invention

[0004] The present invention relates to a foreign body-recovering instrument for an endoscope that is removably inserted into an instrument-inserting channel of an endoscope to recover a foreign body from a body cavity, for example, a swallowed dental crown.

[0005] 2. Description of the Prior Art

[0006] In general, a foreign body-recovering instrument for an endoscope has a plurality of foreign body-catching arms provided at the distal end of a flexible sheath that is removably inserted into an instrument-inserting channel of an endoscope. The foreign body-catching arms are opened or closed by remote control conducted at the proximal end of the sheath. Each foreign body-catching arm has a claw-like portion projecting from the inner side thereof. The claw-like portion is pressed against a foreign body when the foreign body-catching arms are closed to hold the foreign body.

[0007] In actual use of such a conventional foreign body-recovering instrument, a foreign body is caught by pinching it with the foreign body-catching arms from outside the foreign body.

[0008] As shown in FIGS. 22 to 24 by way of example, the foreign body to be recovered may be an object having a smooth surface such as a dental crown 101, or a thin metal piece such as a coin 102, or a tubular small article 103. In such a case, the foreign body is slippery and hence difficult to pinch with the foreign body-catching arms 50. Therefore, there are not a few cases where it is difficult to recover the foreign body.

[0009] In particular, when a foreign body 100 is lodged in a narrow tubular cavity such as a bronchial tube as shown in FIG. 25, it is difficult to open the foreign body-catching arms 50 in excess of the outer diameter of the foreign body 100 and hence impossible to pinch it. Accordingly, it is extremely difficult to recover the foreign body 100.

[0010] An object of the present invention is to provide a foreign body-recovering instrument for an endoscope whereby a foreign body that is difficult to catch and recover by pinching can be readily caught and recovered, depending upon the shape of the foreign body.

[0011] Other objects and advantages of the present invention will become apparent from the following detailed description of illustrated embodiments of the invention.

[0012] According to the present invention, there is provided a foreign body-recovering instrument for an endoscope in which a plurality of foreign body-catching arms are provided at the distal end of a flexible sheath so that the foreign body-catching arms are opened or closed by remote control from the proximal end of the heath. The foreign body-recovering instrument has engaging portions serving as hooks for catching a foreign body. The engaging portions are formed on the respective outer sides of the foreign body-catching arms.

[0013] The present invention may be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings, in which:

[0014] FIG. 1 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a first embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0015] FIG. 2 is a sectional side view of the distal end portion of the foreign body-recovering instrument according to the first embodiment of the present invention, showing a state where the foreign body-catching arms are closed;

[0016] FIG. 3 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a second embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0017] FIG. 4 is a sectional side view of the distal end portion of the foreign body-recovering instrument according to the second embodiment of the present invention, showing a state where the foreign body-catching arms are closed;

[0018] FIG. 5 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a third embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0019] FIG. 6 is a sectional side view of the distal end portion of the foreign body-recovering instrument according to the third embodiment of the present invention, showing a state where the foreign body-catching arms are closed;

[0020] FIG. 7 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a fourth embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0021] FIG. 8 is a sectional side view of the distal end portion of the foreign body-recovering instrument according to the fourth embodiment of the present invention, showing a state where the foreign body-catching arms are closed;

[0022] FIG. 9 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a fifth embodiment of the present invention, showing a state where foreign body-catching arms are closed;

[0023] FIG. 10 is a front view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a sixth embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0024] FIG. 11 is a sectional front view of the distal end portion of the foreign body-recovering instrument according to the sixth embodiment of the present invention, showing a state where the foreign body-catching arms are closed;

[0025] FIG. 12 is a front view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a seventh embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0026] FIG. 13 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to an eighth embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0027] FIG. 14 is a sectional side view of a distal end portion of a foreign body-recovering instrument for an endoscope according to a ninth embodiment of the present invention, showing a state where foreign body-catching arms are open;

[0028] FIG. 15 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0029] FIG. 16 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0030] FIG. 17 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0031] FIG. 18 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0032] FIG. 19 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0033] FIG. 20 is a schematic view showing an example of use of the foreign body-recovering instrument for an endoscope according to the present invention;

[0034] FIG. 21 is a sectional side view of a foreign body-recovering instrument for an endoscope that has a single foreign body-catching arm;

[0035] FIG. 22 is a schematic view showing an example of use of a conventional foreign body-recovering instrument for an endoscope;

[0036] FIG. 23 is a schematic view showing an example of use of the conventional foreign body-recovering instrument;

[0037] FIG. 24 is a schematic view showing an example of use of the conventional foreign body-recovering instrument; and

[0038] FIG. 25 is a schematic view showing an example of use of the conventional foreign body-recovering instrument.

[0039] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0040] FIGS. 1 and 2 show a distal end portion of a foreign body-recovering instrument for an endoscope according to a first embodiment of the present invention. A flexible sheath 1 is removably inserted into an instrument-inserting channel of an endoscope (not shown). A coil pipe is used as the sheath 1. The coil pipe is formed by close-winding a stainless steel wire with a uniform diameter. The sheath 1 has a diameter of the order of from 1.5 millimeters to 2 millimeters and a length of the order of from 1.5 meters to 2 meters.

[0041] A support frame 2 is rigidly secured to the distal end of the sheath 1. The support frame 2 is provided with a slit 3. A pantograph-shaped link mechanism 4 is placed in the slit 3. A pair of foreign body-catching arms 5 are connected to the link mechanism 4. The foreign body-catching arms 5 are rotatably supported by a pivot shaft 6 in the vicinity of the distal end of the support frame 2. The foreign body-catching arms 5 project forward.

[0042] A wire-connecting shaft 7 is connected to the rear end of the link mechanism 4. The distal end of a control wire 8 is connected and secured to the wire-connecting shaft 7. The control wire 8 is axially movably inserted in the sheath 1. The movement of the control wire 8 is controlled at a control part (not shown) that is connected to the proximal end of the sheath 1.

[0043] By virtue of the above-described arrangement, the link mechanism 4 is operated by axially moving the control wire 8 from the proximal end of the sheath 1, thereby enabling the foreign body-catching arms 5 to be opened or closed in a beaklike manner about the pivot shaft 6. It should be noted that FIG. 1 shows a state where the foreign body-catching arms 5 are opened by pushing the control wire 8 toward the distal end of the sheath 1. FIG. 2 shows a state where the foreign body-catching arms 5 are closed by pulling the control wire 8 toward the proximal end of the sheath 1.

[0044] The pair of foreign body-catching arms 5 are each formed in an elongate rod-like shape. Each foreign body-catching arm 5 has an engaging portion 10 at the distal end thereof. The engaging portion 10 projects outward from the outer side of each foreign body-catching arm 5 as viewed in the direction in which the foreign body-catching arm 5 is opened or closed. The engaging portion 10 is formed in the shape of an L that is bent at an acute angle to serve as a hook for catching a foreign body that is to be recovered from a body cavity. The way in which the foreign body-catching arms 5 are used will be described later.

[0045] FIGS. 3 and 4 show a distal end portion of a foreign body-recovering instrument for an endoscope according to a second embodiment of the present invention. FIG. 3 shows a state where the distal end portion of the foreign body-recovering instrument is open. FIG. 4 shows a state where the distal end portion of the foreign body-recovering instrument is closed. A pair of foreign body-catching arms 5 each have an engaging portion 10 that acts as a hook for catching a foreign body that is to be recovered from a body cavity. The engaging portion 10 comprises serrate unevenness (notches) formed on the outer surface of each foreign body-catching arm 5 as viewed in the open-close direction of the foreign body-catching arm 5. The arrangement of the rest of this embodiment is the same as in the first embodiment.

[0046] FIGS. 5 and 6 show a distal end portion of a foreign body-recovering instrument for an endoscope according to a third embodiment of the present invention. FIG. 5 shows a state where the distal end portion of the foreign body-recovering instrument is open. FIG. 6 shows a state where the distal end portion of the foreign body-recovering instrument is closed. In this embodiment, a flexible tube, e.g. a tetrafluoroethylene resin tube, is used as the sheath 1.

[0047] Four foreign body-catching arms 5 are provided at intervals of about 90 degrees as viewed from the front side (from the bottom of the figures). Each foreign body-catching arm 5 is formed from a resilient stainless steel wire or the like that is smoothly curved so as to expand outward.

[0048] It should be noted that the number of foreign body-catching arms 5 is not necessarily limited to four. For example, three foreign body-catching arms 5 may be disposed at intervals of about 120 degrees. Alternatively, two foreign body-catching arms 5 may be spaced at an angle of about 180 degrees. It is also possible to adopt other arrangements of foreign body-catching arms 5. The same is true in the following embodiments.

[0049] A plurality of foreign body-catching arms 5 are bundled together at the proximal ends and inserted into a connecting pipe 9 and secured therein. The connecting pipe 9 is secured to the distal end of the control wire 8 in the sheath 1. Thus, the foreign body-catching arms S are connected to the control wire 8 through the connecting pipe 9.

[0050] Accordingly, when the control wire 8 is pushed in the sheath 1 from the proximal end thereof, the foreign body-catching arms 5 expand in a petal-like shape by their own elasticity, as shown in FIG. 5. When the control wire 8 is pulled toward the proximal end of the sheath 1, the foreign body-catching arms 5 are withdrawn into the distal end of the sheath 1 and elastically deformed to be folded, as shown in FIG. 6.

[0051] Each foreign body-catching arm 5, arranged as stated above, has an engaging portion 10 at the distal end thereof for engagement with a foreign body that is to be recovered from a body cavity. The engaging portion 10 is bent outward in the open-close direction of the foreign body-catching arm 5 to form a U-shaped hook. When the foreign body-catching arms 5 are withdrawn into the sheath 1, as shown in FIG. 6, the engaging portions 10 lie adjacent to the distal end surface of the sheath 1.

[0052] FIGS. 7 and 8 show a distal end portion of a foreign body-recovering instrument for an endoscope according to a fourth embodiment of the present invention. FIG. 7 shows a state where the distal end portion of the foreign body-recovering instrument is open. FIG. 8 shows a state where the distal end portion of the foreign body-recovering instrument is closed. In this embodiment, foreign body-catching arms 5 are each formed from a resilient wire. The distal end of each foreign body-catching arm 5 is bent outward at approximately right angles to form a hook-shaped engaging portion 10.

[0053] As shown in FIG. 7, the distal end half of the intermediate portion of each foreign body-catching arm 5 is bent to deflect slightly inward so that the distal end of the hook-shaped engaging portion 10 lies inside the extension A of the outer wall surface of the foreign body-catching arm 5.

[0054] Consequently, as shown in FIG. 8, the foreign body-catching arms 5 can be withdrawn into the sheath 1 completely so that the engaging portions 10 at the distal ends of the foreign body-catching arms 5 are also withdrawn into the sheath 1. The arrangement of the rest of this embodiment is the same as in the third embodiment.

[0055] FIG. 9 shows a distal end portion of a foreign body-recovering instrument for an endoscope according to a fifth embodiment of the present invention in a state where the distal end portion is closed. This embodiment is the same as the fourth embodiment except that a plurality of foreign body-catching arms 5 have slightly different lengths. Because of the different lengths of the foreign body-catching arms 5, the engaging portions 10 will not interfere with each other in the sheath 1. Therefore, the engaging portions 10 can be received into the sheath 1 even more easily.

[0056] FIG. 10 shows a distal end portion of a foreign body-recovering instrument for an endoscope according to a sixth embodiment of the present invention in a state where the distal end portion is open. This embodiment differs from the fourth embodiment, which is shown in FIGS. 7 and 8, only in the direction in which the engaging portions 10 project from the respective foreign body-catching arms 5.

[0057] In this embodiment, each engaging portion 10 is bent not directly outward in the open-close direction of the foreign body-catching arm 5 but obliquely outward, i.e. in a direction that is halfway between outward and sideward directions.

[0058] By virtue of the above-described arrangement, when the foreign body-catching arms 5 are withdrawn into the sheath 1, the engaging portions 10 can be received in the sheath 1 without interfering with each other, as shown in FIG. 11. It should be noted that each engaging portion 10 may be bent sideward with respect to the open-close direction of the foreign body-catching arm 5 as in a seventh embodiment shown in FIG. 12.

[0059] FIG. 13 shows a distal end portion of a foreign body-recovering instrument for an endoscope according to an eighth embodiment of the present invention in a state where the distal end portion is open. This embodiment differs from the third embodiment, which is shown in FIGS. 5 and 6, only in the shape of the engaging portions 10. In this embodiment, the distal end portion of each foreign body-catching arm 5 is bent outward in a small ring shape to form an engaging portion 10.

[0060] It should be noted that, as shown in a ninth embodiment shown in FIG. 14, the ring-shaped engaging portions 10 may be formed to project both inward and outward from the distal ends of the foreign body-catching arms 5. With this arrangement, the foreign body-recovering instrument can also be used in the same way as in the case of the conventional foreign body-recovering instrument, which recovers a foreign body by pinching it inside the foreign body-catching arms.

[0061] FIGS. 15 to 20 show examples of use of the foreign body-recovering instrument for an endoscope according to the present invention. The foreign body-recovering instrument shown in each of FIGS. 15 to 20 is one of the above-described embodiments. Any of the foreign body-recovering instruments according to the embodiments may be used for each method of use. In any case, the foreign body-recovering instrument is inserted into an instrument-inserting channel of an endoscope.

[0062] FIG. 15 shows the way in which the foreign body-recovering instrument is used to recover a coin 102 with a hole in the center. The foreign body-catching arms 5 are passed through the hole of the coin 102 and then actuated to open. Consequently, the hook-shaped engaging portions 10 are engaged with the back of the coin 102. Therefore, the coin 102 can be readily recovered without dropping.

[0063] As shown in FIG. 16, to recover a coin 102 from a narrow tubular cavity in which the coin 102 cannot be carried in a transverse position, only one foreign body-catching arm 5 is passed through the hole of the coin 102, and the engaging portion 10 is engaged in the hole. In this state, the coin 102 is recovered.

[0064] As shown in FIG. 17, to recover a tubular small article 103 swallowed into a body cavity, the foreign body-catching arms 5 are passed through the tubular small article 103 and then actuated to open. Consequently, the hook-shaped engaging portions 10 are engaged with the end surface on the reverse side of the small article 103. Therefore, the small article 103 can be recovered without dropping.

[0065] To recover a dental crown 101, as shown in FIG. 18, the foreign body-catching arms 5 are inserted into the dental crown 101 and then expanded. Consequently, the engaging portions 10, which are formed on the outer surfaces of the foreign body-catching arms 5, are engaged with the inner peripheral surface of the dental crown 101. Therefore, the dental crown 101 can be recovered without dropping. Although the foreign body-recovering instrument according to the second embodiment, shown in FIGS. 3 and 4, is shown in FIG. 18, it should be noted that the foreign body-recovering instruments according to the other embodiments can also catch and recover the dental crown 101 in the same way as the above.

[0066] Thus, the foreign body-recovering instrument according to the present invention enables the foreign body-catching arms 5 to be engaged with a foreign body from inside it. Therefore, even when a foreign body 100 is lodged in a narrow tubular cavity such as a bronchial tube as shown in FIG. 19, the foreign body-catching arms 5 can be engaged with the foreign body 100. Thus, the foreign body 100 can be readily recovered from the narrow tubular cavity.

[0067] As shown in FIG. 20, a small foreign body 100 can be recovered by engaging only one of a plurality of foreign body-catching arms 5 with the foreign body 100. In the figure, reference numeral 30 denotes an endoscope, and reference numeral 31 denotes an instrument-inserting channel. When used in this way, the foreign body-recovering instrument may be arranged to have only one foreign body-catching arm 5 as shown in FIG. 21.

[0068] According to the present invention, the outer surfaces of a plurality of foreign body-catching arms are provided with engaging portions serving as hooks for catching a foreign body. Therefore, the foreign body-catching arms can be engaged with a foreign body from inside it. Accordingly, a foreign body that has heretofore been difficult to catch and recover by pinching can be readily caught and recovered, depending upon the shape of the foreign body.

[0069] While the invention has been described by reference to specific embodiments chosen for purposes of illustration, it should be apparent that numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.