Endoscopic instrument

An endoscopic instrument includes a rigid hollow shank (2) and a tool (8) at the distal instrument end. The tool (8) is driven in rotation via a drive shaft (14), which is guided within the hollow shank (2). At the distal end of the hollow shank (2), the tool (8) projects out of the hollow shank (2), where it may be angled with respect to the distal end of the hollow shank (2).

BACKGROUND OF THE INVENTION

The invention relates to an endoscopic instrument for removing material, tissue and the like, and having a rigid hollow shank and a tool at the distal instrument end, the tool being driven in rotation via a drive shaft led into the hollow shank.

Instruments are known from the field of medicine, which may be introduced into body cavities via natural or artificially created access channels, in order to remove tissue there with these instruments. Such instruments usually comprise a hollow shank, which may be introduced through the access channel into the body cavity, at whose distal end a rotating tool for removing tissue is arranged in the extension of the hollow shank. Particularly with narrow access channels these instruments come up against limitations, when the tissue to be removed is located laterally of an access axis defined by the access channel.

Instruments are known in which the distal end region, with a tool located thereon, is designed in a rigidly angled manner. Such instruments are described, for example, in U.S. Pat. Nos. 1,677,337 and 4,646,738, as well as German published patent application DE 43 23 756 A1. These instruments with a rigidly angled hollow shank end and tool, however, are not suitable for endoscopic application, since they may not be led through a straight working channel of an endoscope.

Instruments which are basically suitable for this are described in U.S. Pat. Nos. 5,669,926; 5,851,212 and 6,464,711. These instruments have a straight hollow shank, which may be led through the straight working channel of an endoscope. The hollow shanks, with the tool arranged thereon, may be curved transversely away from their original longitudinal axis, for removing body tissue situated laterally of the hollow shank. However, the bending radius of the hollow shanks with these instruments is relatively large, so that the tools arranged at the distal end of the hollow shank may lie outside the scope of endoscopic optics, and an operative operation carried out with these instruments must, as a rule, be observed with additional optical means. A further disadvantage of these instruments lies in the fact that on application of a tool operated in a rotating manner, a drive shaft led through the hollow shank must likewise be bendable, i.e., must be designed in a flexible manner, whereby only relatively small torques at simultaneously low rotation speeds may be transmitted with these drive shafts. For this reason, these instruments are not suitable for removal of hard tissue, such as bone material.

BRIEF SUMMARY OF THE INVENTION

Against this background, it is an object of the invention to provide an endoscopic instrument for removing material, tissue and the like, which may be carried out by a straight working channel of an endoscope. It should also be simultaneously suitable for the removal of hard material and tissue, which may also be arranged laterally of an extension of the working channel of the endoscope.

According to the invention, this object is achieved by an endoscopic instrument, as described above, in which a tool projecting out at the distal end of the hollow shank may be angled with respect to the distal end of the hollow shank.

The endoscopic instrument according to the invention comprises a rigid hollow shank and a tool at the distal instrument end. The tool may be rotatably driven via a drive shaft guided within the hollow shank. According to the invention, the tool at the distal end of the hollow shank projects out of the hollow shank, where it may be angled with respect to the distal end of the hollow shank.

That is, the tool may be angled from a first tool position, in which it forms a straight-line extension of the hollow shank, transverse to its longitudinal axis or rotation axis, into at least one second tool position. Designed in such a manner, the endoscopic instrument according to this embodiment of the invention, on the one hand, may be guided in a first tool position through the working channel of an endoscope to its working region within the cavity, and on the other hand, with this tool it is possible in an angled tool position, to remove material or tissue in a region which is located laterally of an extension of the longitudinal axis of the hollow shank or working channel of the endoscope. With the tool only being angled, and not regions of the hollow shank, the tool is located within the field of view of the optics of the endoscope, even in the angled tool position, so that the tool may be positioned exactly to or on the material or tissue to be removed.

The tool, via suitable coupling means, is coupled in movement to the drive shaft, advantageously in a manner such that it may be driven by the drive shaft in the first as well as the second tool position. With regard to the tool, it may be, for example, a milling tool or a drilling tool or a so-called shaver.

An endoscopic instrument in the context of one embodiment of the present invention may also be a technoscope for technical machining tasks for material removal in otherwise difficulty accessible cavities of machines, motors and the like. Preferably, with regard to the instrument according to the invention, however, it is an endoscopic instrument used in a medical manner, which may be introduced via the working channel of an endoscope for the removal of tissue, in particular bone material in a human or animal body.

Preferably, the tool is arranged in a head part for mounting the tool. This head part is articulated on the distal end of the hollow shank. The head part forms a receiver for the tool at the outer side of the distal end of the hollow shank. The tool is mounted and fastened in a preferably rotatably movable manner in this receiver. The head part, in the region of the distal end of the hollow shank, is preferably pivotable about an axis aligned transversely to the longitudinal axis of the hollow shank. The head part may be moved from a position, in which the tool mounted in the head part is arranged in the extension of the longitudinal axis of the hollow shank, into a position, in which the tool is angled with respect to the longitudinal axis of the hollow shank.

Advantageously, a universal joint is provided in order to be able to actively connect the tool to the drive shaft guided in the hollow shank, also in this position, which is angled with respect to the hollow shank. The universal joint couples the tool in movement to the drive shaft in a direct or indirect manner. The universal joint permits the tool to be angled with respect to the drive shaft led into the hollow shank. Thus, the drive shaft and the tool may be arranged in an axially equal manner in a first position, while the rotation axis of the tool in a second position may be angled with respect to the rotation axis of the drive shaft. The universal joint, on account of its great stiffness in the rotation direction, permits the transmission of relatively large torques in both positions, even at large rotation speeds, which permits the removal of hard material or tissue, in particular the removal of bone tissue.

The tool may be coupled directly to the universal joint. Preferably, however, the drive shaft is divided into at least two parts, wherein the universal joint is arranged between two drive shaft parts. With this design the universal joint connects a proximal-end drive shaft part, actively connected to a drive motor, to a distal-end drive shaft part which is coupled in movement to the tool.

Usefully, a grip part is provided at the proximal end of the instrument according to one embodiment of the invention. The drive shaft may be coupled in movement to the drive motor in this grip part. In order to be able to ensure a cleaning of the endoscopic instrument according to hygienic demands, the drive shaft may also be designed such that it may be divided on the distal end of the grip part and on the proximal end of the universal joint part. Here, a shaft part on the grip part side and at least one shaft part on the hollow shank side may be provided, wherein these two drive shaft parts are preferably designed such that they may be connected to one another with a positive fit.

In order to be able to move the tool into a position which is angled with respect to the distal end of the hollow shank, the head part is usefully coupled in movement via a joint part to an actuation rod, which is movable in the hollow shank in the axial direction. The joint part is preferably articulated on the distal end of the actuation rod and on the head part, wherein on the head part it is usefully also displaceable in a direction transversely to the longitudinal axis of the head part. With this design, having only one device consisting of the actuation rod and the joint part, it is advantageously possible by displacing the actuation rod in the axial direction of the hollow shank, to pivot the head part with the tool arranged therein, into a position which is angled to the distal end of the hollow shank, as well as back into a position which is flush with the hollow shank.

The instrument according to one embodiment of the invention advantageously comprises on the proximal side a handle which is coupled in movement to the actuation rod, for displacing the actuation rod in the hollow shank. This handle is preferably provided on a grip part, which is arranged on the proximal side of the instrument and is coupled in movement to the actuation rod. With regard to the handle, it may be, for example, an actuation lever or actuation slider, by which the head part, with the tool mounted therein, may be moved into a position which is angled with respect to the end of the hollow shank, as well as into a position which is flush with the distal end of the hollow shank. Preferably, the handle is designed as a lever.

In particular, if the endoscopic instrument according to the invention is envisaged for the medical field, a channel may advantageously be designed within the hollow shank, by which tissue particles separated in an operation area may be sucked away, or by which rinsing fluid may be supplied to the operation area. This channel usefully runs out in the region of the distal end of the hollow shank. Its proximal end is usefully conductingly connected to suction means or means for supplying a rinsing fluid. In a preferred design, the drive shaft arranged within the hollow shank forms the channel for supplying and/or leading away rinsing fluid. That is, with this design, the drive shaft is designed as a hollow shank.

In a further preferred design, the actuation rod forms a channel for supplying and/or leading away rinsing fluid. Accordingly, the actuation rod in this case is preferably designed as a tube.

DETAILED DESCRIPTION OF THE INVENTION

The endoscopic instrument represented in the figures comprises a rigid hollow shank2. This hollow shank2is arranged on the distal end of a grip part4. The hollow shank2forms the part of the endoscopic instrument via which the working channel of an endoscope, which is not shown, is introduced into the inside of a body. A head part6is arranged outside the distal end of the hollow shank2, and a tool in the form of a miller head8is mounted in this head part. The head part6at its distal end comprises a closure element10with which the miller head8may be releasably fastened in the head part6. For this, a clamping device is provided in the closure element10, with which device the miller head8may be firmly clamped with a non-positive fit.

The head part6is pivotably mounted about an axis C on a joint12at the distal end of the hollow shank2(seeFIG. 7). The axis C extends normally to a longitudinal axis D of the hollow shank2. The pivotability of the head part6permits the miller head8to be angled with respect to the distal end of the hollow shank2. In order to be able to angle the head part6with respect to the distal end of the hollow shank2, the distal end-side of the hollow shank2is partially beveled. Thus, a region13of the distal end of the hollow shank2is aligned normally to the longitudinal axis D of the hollow shank2, while a region15connecting thereto runs obliquely to this. If the head part6and the miller head8mounted therein are arranged in a direct extension of the hollow shank2, then the proximal end of the head part6bears on the region13. It comes to bear on the region15in the angled position of the head part6(seeFIG. 4).

The miller head8is actively connected to a drive motor arranged in the grip part4, by way of a hollow drive shaft14(seeFIG. 6). The drive shaft14is designed of several parts, wherein a distal drive shaft part16, into which the miller head8engages with a positive fit, is connected via a universal joint18to a drive shaft part20, which connects thereto on the proximal end and which is connected in drive to the drive motor arranged in the grip part4.

The drive shaft part16at its proximal end comprises a slot22running perpendicularly to the end-face there, and the drive shaft part20at its distal end comprises a slot24running perpendicular to the end-face there, for forming the universal joint18.

Apart from this, a dumbbell-shaped joint part is provided, with which a spherical body26is connected via a web28to a spherical body30. A pin32is led through the spherical body26in a manner such that the two ends of the pin32respectively project out of the spherical body26. The pin32is aligned transversely to the web28, which connects the spherical bodies26and30to one another. In a similar manner, a pin34is led through the spherical body30and the distal ends of the pin also respectively project from the spherical body30. The pin34is also aligned transversely to the web28, wherein however it is offset by essentially 90.degree. with respect to the pin32. The spherical body26engages into the proximal end of the hollow drive shaft part16for connecting the drive shaft parts16and20, wherein the ends of the pin32are guided in the slot22of the drive shaft part16. In a similar manner, the spherical body30engages into the distal end of the likewise hollow drive shaft part20, wherein the ends of the pin34are guided in the slot24designed on the drive shaft part20.

The drive shaft part20at its proximal end comprises a slot36running transversely over the entire end-face. This slot serves for coupling to a further grip-side drive shaft part, which is not represented and which at its distal end comprises a projection corresponding with the slot36and engaging into the slot36with a positive fit, in the form of a claw clutch, for coupling this drive shaft part to the drive shaft part20.

An actuation rod38(seeFIG. 7) is provided for bending the head part6with the miller head8mounted therein, at an angle. This actuation rod38is arranged within the hollow shank2between the drive shaft14and the inner wall of the hollow shank2. At the distal end, the actuation rod38comprises an end piece40, which widens to the outside in the radial direction of the hollow shank with respect to the actuation rod38, and which is guided in a longitudinal slot41provided at the distal end of the hollow shank2. A joint part42is articulated on the end-piece40of the actuation rod38. The joint part42is also articulated on the head part6on the end-piece40of the actuation rod, distanced to the articulation.

The actuation rod38is displaceably guided in the hollow shank2in the direction of the longitudinal axis D. The actuation rod38is actuated by way of a handle in the form of a lever44, which is arranged on the grip part4. The head part6, by a movement of the actuation rod38in the proximal direction, is brought into its angled position, in which it bears on the region15of the distal end of the hollow shank2. If the actuation rod38is moved in the distal direction, the head part6pivots back again into such a position, in which it is arranged in the direct extension of the hollow shank2.

The grip part4of the endoscopic instrument is designed in a dividable manner and comprises a proximal-side grip part46and a distal-side grip part48(seeFIG. 3). The drive motor of the instrument is arranged in the grip part46of this instrument. At the distal side, the hollow shank2, with the head part6and the miller head8, connects to the grip part48. Moreover, the lever44for actuating the actuation rod38is arranged on the grip part48. Coupling means50(seeFIG. 5) are provided on the grip part48for the releasable connection of the grip parts46and48, as well as for the releasable coupling of the drive shaft14to the drive motor.