Outer sheathed endoscope

In an outer sheathed endoscope, an outer sheath (20) for shielding a flexible insertion portion (11, 12, 13) from the outside is disposed to detachably cover the flexible insertion portion (11, 12, 13). The basal end of the flexible insertion portion is connected to an operation portion (15). In the outer sheathed endoscope, A break prevention member (100) which is formed by an elastic material is disposed to surround a basal end part of the flexible insertion portion (11, 12, 13), and the outer sheath (20) is formed to cover continuously the flexible insertion portion (11, 12, 13) and the break prevention member (100).

BACKGROUND OF THE INVENTION

The present invention relates to an outer sheathed endoscope in which an outer sheath for preventing an insertion portion from directly contacting with the body wall of a patient is detachably disposed.

In an outer sheathed endoscope, generally, an outer sheath for shielding a flexible insertion portion of the endoscope from the outside is formed so as to detachably cover the flexible insertion portion. When the outer sheath is replaced with a new one for each use, it is possible to completely eliminate infection among patients through the endoscope.

Such an outer sheathed endoscope is configured so that a flexible insertion portion whose outer diameter is substantially constant is simply coupled to an operation portion, thereby enabling the flexible insertion portion to be completely covered with an outer sheath to the extent of reaching a coupling end with the operation portion.

In the configuration in which a flexible insertion portion is simply coupled to an operation portion as described above, however, when the flexible insertion portion is sharply bent in the vicinity of a coupling portion with the operation portion, the flexible insertion portion sometimes buckles or breaks in a relatively easy manner in both a used state where an outer sheath is attached, and a stored state where an outer sheath is not attached.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an outer sheathed endoscope which has excellent durability, and in which a flexible insertion portion does not easily buckle or break in the vicinity of a coupling portion with an operation portion in both a used state where an outer sheath is attached, and a stored state where an outer sheath is not attached.

In order to solve the aforesaid object, the invention is characterized by having the following arrangement.

An outer sheathed endoscope comprising:

an operation portion;

a flexible insertion portion, a basal end of which is connected to the operation portion;

a first break prevention member formed of an elastic material, which is disposed to surround a basal end portion of the flexible insertion portion and attached to the operation portion; and

an outer sheath for shielding the flexible insertion portion form an outside detachably covering the flexible insertion portion and at least a part of the first break prevention member.

The outer sheathed endoscope according to the aspect 1, wherein the outer sheath continuously covers the flexible insertion portion and the first break prevention member.

The outer sheathed endoscope according to the aspect 1, wherein the first break prevention member is formed into a tapered shape in which an outer diameter is gradually reduced, and the outer sheath is formed into a shape in which the outer sheath in the vicinity of the basal end is gradually spread as advancing toward an end part.

The outer sheathed endoscope according to the aspect 4, wherein the outer sheath covers whole of the first break prevention member.

The outer sheathed endoscope according to the aspect 1, wherein the first break prevention member a sheath mounting seat which is detachably engaged with an end of the outer sheath.

The outer sheathed endoscope according to the aspect 5, wherein the sheath mounting seat is one of a groove and a step formed on an outer peripheral face of a tip end part of the first break prevention member.

The outer sheathed endoscope according to the aspect 5, wherein the sheath mounting seat and the first break prevention member are integrally formed of same material.

The outer sheathed endoscope according to the aspect 1, wherein the outer sheath includes a second break prevention member.

The outer sheathed endoscope according to the aspect 8, wherein the second break prevention member surrounds the first break prevention member when the outer sheath is attached to the flexible insertion portion.

The outer sheathed endoscope according to the aspect 8, wherein one of the first and second break prevention member has a constant thickness, and the other of the first and second break prevention member has a thickness which is gradually decreases toward an end thereof.

The outer sheathed endoscope according to the aspect 1, wherein the outer sheathed and the first break prevention member are made of different material.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments according to the invention will be described with reference to the accompanying drawings.

First Embodiment

Referring toFIG. 1,10denotes an endoscope, and20denotes an outer sheath which detachably covers flexible insertion portions11,12and13of the endoscope10in order to insulate the flexible insertion portions11,12and13from the external environment in a used state.

The flexible insertion portions11,12, and13of the endoscope10are configured in the following manner. The bend portion12which can be bent by a remote operation is coupled to the tip end of the long flexible tube portion11. The tip end body portion13in which an observation window14and the like are placed in the tip end face is coupled to the tip end of the bend portion12.

Parts such as a bending operation knob16which remotely bends the bend portion12are placed in an operation portion15which is coupled to the basal end of the flexible tube portion11. When the bending operation knob16is rotated, the bend portion12is bent.

A break prevention member100which is formed by an elastic material into a tapered tubular shape in which the outer diameter is gradually reduced is attached so as to surround a basal end part of the flexible tube portion11. The reference numeral101denotes an attachment socket which is made of a metal, and which is formed integrally with the break prevention member100.

As shown in detail inFIG. 3which will be described later, the break prevention member100is formed into a shape in which the thickness is gradually reduced as advancing toward the tip end. As indicated by the two-dot chain line inFIG. 1, even when the flexible tube portion11is bent in a stored state of the endoscope10, the break prevention member100functions so as not to cause the coupling portion with the operation portion15to be sharply bent, thereby preventing the flexible tube portion11from buckling or breaking.

A guide conduit17which is formed by, for example, a flexible polyethylene resin tube is placed so as to elongate from the interiors of the flexible insertion portions11,12, and13to the interior of the operation portion15. A tip end opening17aof the guide conduit17is formed in the tip end face of the tip end body portion13.

A forceps port member30is placed at a position which is opposed to a basal end opening of the guide conduit17and is placed in the operation portion15. A forceps plug32is attached to an insertion port of the forceps port member30.

In the outer sheath20, a cover tube21which is formed into a thin cylindrical shape by an elastic material, such as a silicone rubber tube, is disposed so as to detachably cover the flexible tube portion11and the bend portion12of the endoscope10. An end cap22which is formed by a transparent member, and which is to cover the tip end body portion13is watertightly attached to the tip end of the tube.

A coupling ring24fixed to the basal end of the cover tube21is detachably engageable with a coupling portion19between the operation portion15of the endoscope10and the flexible tube portion11. A fixing mechanism25can be arbitrarily engaged with a circumferential groove19awhich is formed in the coupling portion19.

As shown in detail also inFIG. 3which will be described later, a basal end neighboring portion21aof the cover tube21which is coupled to the coupling ring24is formed into a shape in which the diameter is gradually spread as advancing toward the end in conformity with the shape of the break prevention member100.

A flexible channel tube23(in the embodiment, a treatment tool insertion channel) which is formed by, for example, a flexible tetrafluoroethylene resin tube is passed through the whole length of the cover tube21.

The tip end of the flexible channel tube23is fixed to the end cap22so as to be opened to the outer face in the end face of the end cap22. A basal end part23aof the flexible channel tube23elongates rearward with passing through the coupling ring24.

The flexible channel tube23is insertable and extractable over the whole length of the guide conduit17of the endoscope10. As indicated by the arrow of the long-short dash line, the basal end part23aof the flexible channel tube23can be inserted into the tip end opening17aof the guide conduit17and can be pulled out from the basal end opening.

FIG. 2shows the used state where the outer sheath20covers the flexible insertion portions11,12, and13of the endoscope10so that the end cap22abuts against the tip end face of the tip end body portion13.

In this state, as described above, the coupling ring24of the outer sheath20is fixed to the coupling portion19of the endoscope10, and the basal end neighboring portion21aof the cover tube21covers the break prevention member100, thereby forming a state where the flexible insertion portions11,12, and13and the break prevention member100are continuously covered with the outer sheath20.

FIG. 3shows in detail the vicinity of the break prevention member100in the used state. The incorporated articles such as the flexible channel tube23are not shown in the figure. In the flexible tube portion11, a basal end socket11ais fixed to a frame15aof the operation part15by a pressing ring9which is screwed to an end portion of the frame15a.

The attachment socket101which is integrated with the break prevention member100is screwed to and fixed to the frame15aof the operation portion15. When the screw fixation is loosed, the break prevention member100can be detached from the flexible tube portion11.

The fixing mechanism25has a configuration in which an engagement pin25ato be engaged with the circumferential groove19aof the coupling portion19is inwardly urged by a compression coil spring25b. When a knob25cwhich outwardly protrudes is pulled up by fingers, the engagement pin25acan be disengaged from the circumferential groove19a.

Since the basal end neighboring portion21aof the cover tube21is formed into the shape in which the diameter is gradually spread as advancing toward the end in conformity with the shape of the break prevention member100, the flexible tube portion11and the break prevention member100are covered smoothly and continuously by the cover tube21. According to the configuration, in the used state of the endoscope, not only the surface of the flexible tube portion11but also the break prevention member100is insulated from a contaminated area.

As indicated by the tow-dot chain line inFIG. 2, even when the flexible tube portion11of the endoscope10is bent in the used state, the break prevention member100functions so as not to cause the coupling portion with the operation portion15to be sharply bent, thereby preventing the flexible tube portion11from buckling or breaking.

In the used state of the endoscope10, at the same time when the outer sheath20covers the flexible insertion portions11,12, and13, the flexible channel tube23is passed through the guide conduit17.FIG. 4shows the vicinity of the basal end of the guide conduit17in this sate.

A forward portion of the forceps port member30is fittingly inserted in an advanceable and retractable manner into a cylinder hole18which is formed as a deep countersunk hole in the basal end opening portion of the guide conduit17. The basal end part23aof the flexible channel tube23is fixed to the forceps port member30in an insertable and extractable manner. The reference numeral31denotes a forceps passage which is formed in the forceps port member30.

An O-ring33for the purposes of sealing and click attachment is attached to the forceps port member30into which the basal end part23aof the flexible channel tube23is inserted. The O-ring33is engaged with a circumferential groove which is formed in the outer peripheral face of the basal end part23aof the flexible channel tube23, thereby fixing the basal end part23aof the flexible channel tube23to the forceps port member30.

The flexible channel tube23is axially advanceable and retractable over the whole length of the guide conduit17. The forceps port member30is always outwardly (leftward inFIG. 4) urged by a compression coil spring40placed in the cylinder hole18. As a result, there arises a state where the flexible channel tube23is always pulled toward the forceps port member30by the urging force of the compression coil spring40.

According to the configuration, when the bend portion12is bent by operating the bending operation knob16to exert an axial compression force on the flexible channel tube23, the forceps port member30is moved along a direction in which the member outwardly protrudes from the cylinder hole18to absorb the compression force acting on the flexible channel tube23.

By contrast, when an axial pulling force acts on the flexible channel tube23, the forceps port member30is moved along a direction in which the member enters the cylinder hole18to absorb the pulling force acting on the flexible channel tube23. As a result, an excessive force does not act on the flexible tube portion11, the bend portion12, etc.

In the case where a so-called multi-lumen tube is used as the flexible channel tube23, as shown inFIG. 5, the basal end part may be further elongated to the outside with being fixed to the forceps port member30, and then connected to a gas and water feeding apparatus or the like which is not shown.

The reference numeral34denotes an engageable locking O-ring which restricts the guide conduit17from slipping off from the forceps port member30,23bdenotes a side hole which is formed in the flexible channel tube23to communicate a forceps insertion hole (serving also as a suction port) of the flexible channel tube23with the forceps passage31,23sdenotes a closing plug which closes an end of a lumen that is used for suction, and50denotes a suction tube.

According to the invention, a break prevention member which is formed by an elastic material is disposed to surround a basal end part of a flexible insertion portion, and an outer sheath is formed to cover continuously the flexible insertion portion and the break prevention member. In both a used state where the outer sheath is attached, and a stored state where the outer sheath is not attached, therefore, the flexible insertion portion does not easily buckle or break in the vicinity of a coupling portion with an operation portion, and excellent durability can be obtained.

Second Embodiment

FIGS. 6to9show a second embodiment of the invention. The components identical with those of the first embodiment are denoted by the same reference numerals, and their description is omitted.

The second embodiment is different from the first embodiment in the configurations of the outer sheath and the break prevention member. Therefore, the second embodiment will be described with placing emphasis on the differences.

A break prevention member attachment socket101made of a metal is disposed in a basal end part of the break prevention member100. A sheath mounting seat102is molded integrally with a tip end part of the break prevention member100.

A coupling ring224is fixed to the basal end of the cover tube21. The coupling ring224is detachably engageable with the sheath mounting seat102. An engagement protrusion225which protrudes from the inner face of the coupling ring224can be arbitrarily engaged and disengaged with the sheath mounting seat102having a circumferential groove-like shape.

FIG. 7shows the used state where the outer sheath20covers the flexible insertion portions11,12, and13of the endoscope10so that the end cap22abuts against the tip end face of the tip end body portion13.

In this state, the coupling ring224disposed on the basal end of the outer sheath20is engaged with the sheath mounting seat102formed in the tip end part of the break prevention member100of the endoscope10.

The break prevention member attachment socket101is integrated with the break prevention member100, and screwed and fixed to the frame15aof the operation portion15. When the screw fixation is loosed, the break prevention member100can be detached.

In the embodiment, the sheath mounting seat102is the circumferential groove which has a V-like section shape, and which is formed in the outer peripheral face of the tip end part of the break prevention member100, and the engagement protrusion225which is formed on the inner face of the coupling ring224is detachably engaged with the mounting seat. An operation of engaging or disengaging the engagement protrusion225with the sheath mounting seat102is performed by elastically deforming both or one of the coupling ring224and the sheath mounting seat102.

In this way, the engagement protrusion225of the coupling ring224is engaged with the sheath mounting seat102, whereby the flexible insertion portions11,12, and13of the endoscope10are fixed in the state where the portions are covered with the outer sheath20, to be insulated from a contaminated area in a used state.

The invention is not restricted to the embodiments described above. For example, as shown inFIG. 9, the break prevention member100may have a cylindrical shape of a constant thickness, or another shape. The sheath mounting seat102may be a step or the like with which the engagement protrusion225formed on the coupling ring224can be detachably engaged. The break prevention member attachment socket101may be configured with being separated from the break prevention member100.

According to the invention, a sheath mounting seat with which the basal end of an outer sheath is to be detachably engaged is formed on a tip end part of a break prevention member which is disposed to surround a basal end part of a flexible insertion portion. In both a used state where the outer sheath is attached, and a stored state where the outer sheath is not attached, the flexible insertion portion does not easily buckle or break in the vicinity of a coupling portion with an operation portion, and excellent durability can be obtained.

Third Embodiment

FIGS. 10to13show a third embodiment of the invention. The components identical with those of the first embodiment are denoted by the same reference numerals, and their description is omitted.

The third embodiment is different from the first embodiment in the configurations of the outer sheath and the break prevention member. Therefore, the third embodiment will be described with placing emphasis on the differences.

A first break prevention member11A which is made of an elastic material and has a cylindrical shape is attached to surround a basal end part of the flexible tube portion11. The reference numeral319denotes a fixing ring which fixes the first break prevention member11A to the operation portion15.

As shown in detail inFIG. 12which will be described later, the first break prevention member11A is formed into a cylindrical shape in which the thickness is substantially constant as a whole. As indicated by the two-dot chain line inFIG. 10, even when the flexible tube portion11is bent in a stored state of the endoscope10, because of the presence of the first break prevention member11A, the first break prevention member11A functions so as not to cause the coupling portion with the operation portion15to be sharply bent, thereby preventing the flexible tube portion11from buckling or breaking.

FIG. 11shows the used state where the outer sheath20covers the flexible insertion portions11,12, and13of the endoscope10so that the end cap22abuts against the tip end face of the tip end body portion13.

In this state, an attachment socket324aof the outer sheath20is fixed to the fixing ring319of the endoscope10, and a second break prevention member324of the cover tube21surrounds the first break prevention member11A.

FIG. 12shows in detail the vicinity of the first and second break prevention members11A and324in this state. The incorporated articles such as the flexible channel tube23are not shown in the figure. In the flexible tube portion11, the basal end socket11ais fixed to the frame15aof the operation portion15by the pressing ring9which is screwed to an end part of the frame15a.

In the first break prevention member11A, a collar portion which protrudes in a flange-like manner from the basal end is pressingly fixed to the frame15aby the fixing ring319which is screwed with the frame15aof the operation portion15. The attachment socket324aof the second break prevention member324is fixed to the fixing ring319by fastening a manual fixing screw25toward the outer peripheral face of the fixing ring319. As a result, during a used state of the endoscope, not only the surface of the flexible tube portion11but also the first break prevention member11A is insulated from a contaminated area.

In this state, the second break prevention member324is set to a position where it surrounds the first break prevention member11A. As a result, as indicated by the two-dot chain line inFIG. 11, even when the flexible tube portion11of the endoscope10in a used state is bent, the first break prevention member11A and the second break prevention member324function so as not to cause the coupling portion with the operation portion15to be sharply bent, thereby preventing the flexible tube portion11from buckling or breaking.

Since the first break prevention member11A and the second break prevention member324are formed so as to radially overlap each other, the length can be shortened. Therefore, the root part of the operation portion15which is hardly bent is not much long, and hence excellent operability can be ensured.

The invention is not restricted to the embodiments described above. For example, as shown inFIG. 13, the first break prevention member11A may be formed into a tapered shape in which the thickness is gradually reduced as advancing toward the tip end, and the second break prevention member324may be formed so as to have a constant thickness. Alternatively, both the members may be formed into a shape in which the thickness is gradually reduced as advancing toward the tip end.

Alternatively, each of the first break prevention member11A and the second break prevention member324may be formed so as to have a constant thickness while setting the material of a part on the side the tip end to be softer than that of a part on the side of the basal end.

According to the invention, a first break prevention member made of an elastic material is disposed to surround a basal end part of a flexible insertion portion, and a second break prevention member made of an elastic material is disposed in an outer sheath to surround the first break prevention member in a state where the outer sheath is attached to the flexible insertion portion. Therefore, a root part of an operation portion which is hardly bent is not required to be made very long, and, in both a used state where the outer sheath is attached, and a stored state where the outer sheath is not attached, the flexible insertion portion does not easily buckle or break in the vicinity of a coupling portion with an operation portion, and excellent durability and operability can be obtained.