Soft bipolar forceps

A soft bipolar forceps includes a long narrow flexible tube; paired forceps pieces that are formed extending in the axial direction, and are mutually insulated and disposed opposite one another; and a support that is disposed to the distal end of the flexible tube and supports the paired forceps pieces to permit relatively free opening and closing thereof; characterized in that a first electrode is disposed to one of the paired forceps pieces, a second electrode is disposed to the other of the paired forceps pieces opposite the first electrode, and a guide part that extends to permits elastic deformation is disposed to the distal end of the first electrode.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a soft bipolar forceps.

Priority is claimed on Japanese Patent Application No. 2006-113401, filed Apr. 17, 2006, the content of which is incorporated herein by reference.

2. Description of Related Art

Endoscopic procedures are being used increasingly in the treatment of diseases of the digestive and pancreatobiliary systems. Procedures performed on the pancreatobiliary system that employ conventional endoscopes include therapeutic procedures, such as the retrieval of choleoliths present in biliary ducts using a balloon or grasping tool, as well as diagnostic procedures for endoscopic visualization of the pancreatic or biliary ducts.

When performing such endoscopic procedures on the pancreatic, biliary, or hepatic ducts, the distal end of the inserted portion of the endoscope is inserted as far as the proximity of the duodenal papilla. From this point, the guide wire disposed in the contrast catheter is employed as a guide to insert a papillotomy knife into either the pancreatic or biliary duct selectively under fluoroscopy, and a duodenal papillotomy for opening the duodenal papilla is carried out. (See, for example: Japanese Patent Application, First Publication No. Hei 11-033033, Japanese Patent Application, First Publication No. Hei 11-128240).

In addition, in place of a papillotomy knife, it is also possible to employ a high-frequency forceps that is able to incise the subject tissue only when the paired forceps pieces are closed, each of these paired pieces having a cutting electrode and a recovery electrode disposed respectively therein (for example, see: Japanese Patent Application, First Publication No. Hei 05-253241).

SUMMARY OF THE INVENTION

The present invention was conceived in view of the above-described circumstances and employs the following means.

The soft bipolar forceps according to the present invention is provided with a long narrow flexible tube; a pair of forceps pieces that are formed extending in the axial direction, and are mutually insulated and disposed opposite one another; and a support that is disposed to the distal end of the flexible tube and supports the paired forceps pieces to permit relatively free opening and closing thereof; characterized in that a first electrode is disposed to one of the paired forceps pieces, a second electrode is disposed to the other of the paired forceps pieces opposite the first electrode, and a guide part that extends in the axial direction and permits elastic deformation is disposed to the distal end of the first electrode.

The soft bipolar forceps according to the present invention is further characterized in that a through hole is provided in the axial direction of the guide part in the above-described soft bipolar forceps.

The soft bipolar forceps according to the present invention is further characterized in that, in the soft bipolar forceps as described above, the guide part is provided with conductive properties.

The soft bipolar forceps according to the present invention is further characterized in that, in the soft bipolar forceps as described above, the first electrode is formed in a unitary manner with the guide part in a manner that enables elastic deformation.

The soft bipolar forceps according to the present invention is further characterized in that, in the soft bipolar forceps as described above, an insulating part for electrically insulating between the paired forceps pieces is disposed to the aforementioned support.

The soft bipolar forceps according to the present invention are further characterized in that, in the soft bipolar forceps as described above, the insulating part which electrically insulates between the paired forceps pieces is disposed to the respective base ends of the paired forceps pieces.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of the present invention will now be explained with reference toFIGS. 1 through 4.

As shown in theFIG. 1, in the soft bipolar forceps1according to this embodiment, a long narrow flexible tube3, into which a pair of operating wires2A,2B have been inserted, and a pair of forceps pieces5,6, which are formed extending in the axial direction and are mutually insulated and disposed opposite one another, are connected to the distal end of flexible tube3via a connecting member7. Soft bipolar forceps1is further provided with a tip cover (support)8for supporting the paired forceps pieces5,6to permit relatively free opening or closing thereof, and an operator10for advancing or retracting the paired operating wires2A,2B with respect to flexible tube3.

A first electrode11which is formed of stainless steel and is in the shape of a straight tube is disposed to the forceps piece5. As shown inFIGS. 2 and 3, the first electrode11is formed to permit engagement at its distal end with the outer peripheral surface of the forceps piece5. The forceps piece5is provided with a first arm12, a first connector13and a guide part15. The first arm12extends along the center axis C of the forceps piece5. The first connector13moves away from the center axis C in the cross direction with respect to the first arm12and bends. After moving a set distance away from the center axis C, this first connector13bends again to extend along the center axis C direction. The guide part15extends in the axial direction and is designed to enable elastic deformation at the distal end of the first electrode11. A first through hole13ais formed in the approximate center of the first connector13to permit passage through the first connector13in the cross direction. A conductive part13bis provided to the base end of the first connector13, and the operating wire2A is connected thereto.

The guide part15extends linearly from the first electrode11in the axial direction, and has a through hole15a. This guide part15is designed to be in the form of a stainless steel coil that is elastically deformable, and can engage with the inner peripheral surface of the distal end side of the first electrode11. An end tip16in which a hole16ais provided that communicates with the through hole15ais disposed at the end of the guide part15.

A second electrode17is disposed opposite the first electrode11and serves as a different terminal than the first electrode11. This second electrode17is approximately the same length as the first electrode11and is formed to have a roughly triangular shape in cross-section such that the width gradually narrows in the direction of the forceps piece5side. In other words, when the pair of forceps pieces5,6are closed, the first electrode11and the second electrode17are designed to form a linear connection.

The forceps piece6is further provided with a second arm18that extends further than the first arm12, and a second connector20bends in a direction away from the first arm12, from the center axis C in the cross direction with respect to the second arm18. After moving a set distance away from the center axis C, this second connector20bends again to extend along the center axis C direction. The second electrode17is disposed to the second arm18. A second through hole20ais formed in the approximate center of the second connector20to permit passage through the second connector20in the cross direction. A conductive part20bis provided to the base end of the second connector20, and the operating wire2B is connected thereto.

Tip cover8consists of an insulated member formed of a ceramic such as zirconia, alumina or the like, or a resin such as polyetherether ketone (PEEK), polytetrafluoroethylene (PTFE), or polysulfone. Alternatively, tip cover8may consist of a member in which an insulating coating is applied to a stainless surface. The tip cover8is provided with a projecting part8A that extends along the center axis C direction, and a base part8B which is connected to the connecting member7. A third through hole8awhich communicates with the first through hole13aand the second through hole20ais provided in the cross direction in the center of projecting part8A. Further, the first connector13and the second connector20which are disposed on either side of projecting part8A are connected in a freely rotating manner about a pivot support pin21.

Stop pin22which is projecting out in the cross direction is provided to the first connector13. The first connector13is engaged by the stop pin22in an engaging hole23formed in the projecting part8A. As a result, relative movement of forceps piece5and tip cover8is restricted even if operating wire2A is advanced or retracted. On the other hand, the second connector20rotates around the pivot support pin21by advancing or retracting the operating wire2B, so that the second arm18can be opened or closed with respect to the first arm12.

The first connector13, the pivot support pin21, the projecting part8A and the second connector20are electrically insulated by an insulating spacer (insulating part)25. In other words, the first electrode11and the second electrode17are electrically insulated by the insulating spacer25.

The operator10is provided with a long, narrow operator main body26and a slider27which is disposed in a freely advancing and retracting manner with respect to the operator main body26. A ring28for hooking the finger is provided to the base end of the operator main body26. A slit30is provided further toward the front of the operator main body26than the ring28. A pair of operating wires2A,2B are inserted into the operator main body26. A pair of electrical terminals32A,32B to which a power source cord31is connected are embedded in the slider27. The base end side of the operating wire2A enters a state of connection with electrical terminal32A by means of the advance and retraction of the slider27, while the base end of the operating wire2B is in a fixed connection with electrical terminal32B.

Next, using a duodenal papillotomy as an example, an operation using the soft bipolar forceps1according to this embodiment will be explained.

First, the inserted part35of the endoscope33is inserted into the body cavity and disposed near the duodenal papilla36. Then, the soft bipolar forceps1is inserted into the instrument insertion channel37that is provided in the inserted part35, and is made to project out from the distal end of the inserted part35in the direction of the biliary duct39. At this point, the guide wire38, previously inserted into the instrument insertion channel37by a specific method, is inserted into the forceps piece5and made to project out. Power source cord31is connected to a high frequency power source not shown in the figures. Here, operating wire2A is the positive electrode and operating wire2B is the negative electrode.

When carrying out a procedure, the finger is suspended in the slider27and the ring28of the operator main body26, the slider27is advanced, and the operating wire2B is advanced with respect to the flexible tube3. At this time, the base end of the forceps piece6is pushed in the forward direction of the operator main body26by the operating wire2B, causing the forceps piece6to rotate about the pivot support pin21in a direction away from the forceps piece5.

In this state, the inserted part35and the entirety of the soft bipolar forceps1is advanced, and the guide part15is inserted into the biliary duct39, to enter the state shown inFIG. 4. In this case, since the guide part15is elastically deformable, it undergoes bending and can be inserted smoothly into the biliary duct39. Once the forceps pieces5has been inserted to a position that enables gripping of the diseased area between the first electrode11and the second electrode17, the slider27is retracted with respect to the operator main body26. The operating wire2B is retracted at this time, and the forceps piece6is rotated about the pivot support pin21so that the second arm18approaches the first arm12, and a specific diseased area such as the papilla36that is to be incised is held between the first electrode11and the second electrode17.

By activating the high frequency power source, electrical energy is supplied to the first electrode11and the second electrode17via the paired operating wires2A,2B, and current is passed through the diseased area to incise it. Once the procedure is done, supply from the high-frequency power source is stopped. Slider27is retracted and the grip on the diseased area is released by rotating the forceps piece6around the pivot support pin21in the direction away from the forceps piece5, and the flexible bipolar forceps1is withdrawn from the body together with the inserted part35.

In this soft bipolar forceps1, the guide part15is inserted into such as the hepatic duct39, and, in this state of insertion, the diseased area is gripped by the paired forceps pieces5,6. Current from the high-frequency power source is then passed between the first electrode11and the second electrode17. Accordingly, the diseased area can be incised in a stable manner using the soft bipolar forceps1of the present invention. Moreover, since the guide part15is elastically deformable, it can be inserted easily into the hepatic duct39. Accordingly, the duration of the procedure can be shortened.

Instruments such as the guide wire38, etc., required for the procedure can be inserted into the forceps5piece, and the soft bipolar forceps1can be moved using through hole15a. Since the guide part15also possesses conductivity, the guide part15and the first electrode11enter a state of conductivity, so that current can flow between the guide part15and the second electrode17as well.

Next, a second embodiment of the invention will be explained with reference toFIG. 5.

Note that compositional elements that are equivalent to those of the first embodiment have been assigned the same numeric symbols, and a description thereof is omitted.

The difference between the first and second embodiments is that the guide part41of the soft bipolar forceps40according to the second embodiment is a tube that has both conductive properties and pliability.

The guide part41has conductivity through the use of carbon, for example, and engages with the outer peripheral surface of the front end side of the first arm12of the forceps piece42. An end tip16is provided to the distal end of the guide part41.

Actions and effects equivalent to those of the first embodiment can be achieved using this soft bipolar forceps40. In particular, since a tube instead of a coil member is employed for the guide part41, the guide part41can be smoothly inserted into the papilla36.

Next, a third embodiment of the invention will be explained with reference toFIG. 6.

Note that compositional elements that are equivalent to those of the other embodiments have been assigned the same numeric symbols, and a description thereof is omitted.

The second and third embodiments differ from one another in that the guide part46of the soft bipolar forceps45according to this embodiment is a tube that possesses both insulating properties and pliability.

The guide part46consists of a resin, for example, and engages with the outer peripheral surface of the front end side of the first arm12of the forceps piece47in the same manner as in the second embodiment.

Next, the operation of the soft bipolar forceps45according to this embodiment will be explained.

First, as in the case of the first embodiment, the diseased area that is to be incised is gripped by the paired forceps pieces47,6.

Electrical energy is supplied to the first electrode11and the second electrode17via the paired operating wires2A,2B through the activation of the high-frequency power source, so that current flows through the diseased area held between the paired forceps pieces47,6, causing cutting. In contrast, current does not flow through the biological tissue that is in contact with the guide part46, so cutting does not occur.

This soft bipolar forceps45enables current to flow only though the part that is gripped between the first electrode11and the second electrode17.

Next, the fourth embodiment will be explained with reference toFIG. 7.

Note that compositional elements that are equivalent to those of the other embodiments have been assigned the same numeric symbols, and a description thereof is omitted.

The difference between the forth and first embodiments is that the first electrode52of the forceps piece51in the soft bipolar forceps50according to the forth embodiment is elastically deformable and is formed in a unitary manner with the guide part41according to the second embodiment.

Namely, the first electrode52forms the guide part and is disposed extending toward the front end of the forceps piece51.

In this soft bipolar forceps50, the diseased area can be incised in the same manner as in the preceding embodiments, by gripping the diseased area between the paired forceps pieces51,6. In particular, it is possible to insert only a pliable component since there is no rigid portion in the inserted part.

Note that the technical scope of the present invention is not limited to the above-described embodiments. Rather, various modifications are possible so long as they do not depart from the spirit of the invention.

For example, in the preceding embodiments, the paired forceps pieces are insulated by means of an insulating spacer25that is disposed to the tip cover8. However, instead of this insulating spacer25, it is also acceptable to provide an insulating coating to the base end of the paired forceps pieces as the insulating part. In this case, it is possible to have direct insulation between the forceps pieces.

Further, in the preceding embodiments, the guide part and the first electrode extend linearly, however it is also acceptable to form them in a curved shape with a pre-determined curving rate.

The present invention enables a target body tissue to be easily incised while being held stably between paired forceps pieces, and permits shortening of the procedure time. The incision of the subject tissue is performed by transmitting a current between the first electrode and the second electrode when the subject tissue is held between the paired forceps pieces. In this case, when the subject tissue is tubular for example, it is possible to position one of the forceps pieces with respect to the subject tissue by inserting the guide part into the subject tissue, and to grip the wall of the tube stably between the paired forceps pieces.

The present invention also enables the insertion of the instruments required for the procedure into the through hole, and enables movement of the instruments via the through hole. It is possible to further increase the axial length of the elastically deformable part, facilitating insertion into a tubular space.

Because there is a state of conductivity between the guide part and the first electrode, it is possible for current to flow between the guide part and the second electrode in the present invention. The present invention also enables the electrical insulation between the paired forceps pieces at the support to be suitably maintained by the insulating part. As a result, electrical insulation of both paired forceps pieces can be suitably maintained even if their base ends come into direct contact.