The present invention relates to a tool for a distal end or on a distal end of a shaft of a medical instrument and to a medical instrument having such a tool.
Medical devices and medical personnel prefer medical instruments which can be used as variously as possible. The more variously the individual medical instrument can be used, the smaller the variety of instruments to be held in readiness. Variously usable medical instruments, consequently, can reduce the investment costs necessary in a medical setup even where unit costs are high. A small variety and a smaller number of medical instruments to be kept in readiness can also reduce costs for storage and logistics.
In the case of micro-invasive medical instruments or medical instruments for micro-invasive interventions, there is also the fact that during an intervention the less often instruments have to be changed, the more variously the individual instrument can be used.
An object of the present invention is to create an improved tool for a distal end or on a distal end of a medical instrument and an improved medical instrument. An object, in particular, is, in the case of a tool with a pivotable mouth part, to make possible an operating channel in which a scalpel or another acting element is able to be arranged and moved.
This object is achieved by the objects of the independent claims.
Further developments are provided in the dependent claims.
A tool for a distal end or on a distal end of a shaft of a medical instrument includes a basic body, a mouth part which is pivotable about a pivot axis in relation to the basic body, and a bearing which defines the pivot axis, wherein the bearing includes two axial pins which are spaced apart from one another, each with a radial surface which is rotationally symmetrical with respect to the pivot axis.
The tool is realized for (in particular detachable) mechanical coupling with the distal end of a shaft or is mechanically connected (in particular so as to be detachable without damage) to the distal end of a shaft. In this case, the shaft is a component part of a medical instrument or is provided for forming a medical instrument.
At the proximal end or in a proximal region, the basic body has a coupling for the detachable mechanical coupling with a distal end of a shaft. As an alternative to this, the basic body is mechanically connected to the distal end of a shaft in a permanent manner and so as to be detachable without damage. The tool can have a further mouth part which is not movable in relation to the basic body. Said further mouth part is connected in particular to the basic body in a rigid manner or is realized integrally with said basic body. As an alternative to this or in addition to it, the tool can have one or several further movable, in particular pivotable, mouth parts.
The bearing can include more than two axial pins which are spaced apart from one another, each having a radial surface which is rotationally symmetrical with respect to the pivot axis of the mouth part. Each individual axial pin is connected in a rigid manner either to the pivotable mouth part or to the basic body.
As described below and as is shown in detail by way of the exemplary embodiments, the two (or more) axial pins, which are spaced apart from one another, create new structural degrees of freedom.
A tool, as is described here, additionally includes, in particular, an operating channel in which a scalpel or another acting element can be displaced between a proximal and a distal position.
The scalpel is provided and realized, in particular, for cutting through tissue which is grasped by means of the tool. For example, the tool is realized for the monopolar or bipolar electro-cauterization of tissue grasped by means of the tool. A vessel or other tissue can be grasped, squeezed, scelerosed electro-surgically or HF-surgically by means of the tool and then cut through by means of the scalpel. The ability to carry out all of said procedure steps using one single tool can clearly reduce the time taken for a micro-surgical intervention. Instead of for a scalpel, the operating channel can be usable for other working elements which can be inserted with the tool in an open and/or a closed position.
In the case of a tool with an operating channel, as is described here, the operating channel is arranged, in particular, between the axial pins.
The operating channel extends, in particular, from a handling device along a shaft as far as up to the tool and to the active region of the pivotable mouth part. An arrangement of the operating channel between the axial pins means that the operating channel leads through between the axial pins or at least part of the lumen of the operating channel lies between the axial pins.
In the case of an almost arbitrary arrangement of the pivot axis of the pivotable mouth part, the bearing with two (or more) axial pins, which are spaced apart from one another, makes possible a large cross section or a large lumen of the operating channel, at least in the direction at right angles with respect to the longitudinal axis of the tool and at right angles with respect to the pivot axis. Comparable cross sections of the operating channel are possible in the case of a bearing with a continuous shaft at most where the shaft is arranged at a large spacing from the center of the cross section and there is a small spacing between the shaft and the outer edge of the cross section of the tool. However, said arrangement of the shaft is only possible with a circular cross section of the tool if the shaft is short, which results in other structural disadvantages.
In the case of a tool, as is described here, the basic body of the tool includes, in particular, two parallel walls, between which a portion of the operating channel is arranged, wherein each of the two parallel walls has a recess in which one of the two axial pins engages.
The two parallel walls are realized, in particular, as webs on a base plate.
The two (or more) parallel walls are arranged, in particular, parallel with respect to the longitudinal axis of the tool or of a shaft which is connected to the tool or is to be connected to the tool and at right angles with respect to the pivot axis of the pivotable mouth part. The two parallel walls define, in particular, the operating channel on two opposite sides such that the operating channel is defined at least in portions by the two opposite walls. Each recess is formed, in particular, by a blind hole in one of the two parallel walls. As an alternative to this, the two recesses are formed by one single through-bore which penetrates the two parallel walls.
In the case of a tool, as is described here, the bearing includes additionally, in particular, recesses which correspond to the axial pins, wherein the axial pins engage in the recesses from the outside.
As already mentioned for the embodiment with two parallel walls, in other cases the recesses which correspond to the axial pins can also be formed by one single through-bore, the axial pins engaging in the two opposite ends of the through-bore. The term engage from the outside refers to an engagement from two opposite directions where the axial pins project toward one another.
In the case of a tool, as is described here, the bearing additionally, in particular, includes recesses which correspond to the axial pins, wherein the axial pins engage in the recesses from the inside.
The phrase the axial pins engage in the recesses from the inside refers to the axial pins projecting in two opposite directions facing away from one another.
In the case of a tool, as is described here, the mouth part includes, in particular, two axial pin components each with one of the axial pins.
Each axial pin component is produced, in particular, in one piece. At the proximal end thereof, each axial pin component includes, in particular, the associated axial pin and an arm or bar which extends substantially at right angles with respect to the pivot axis of the pivotable mouth part. If the axial pin components are component parts of the pivotable mouth part, the arms or bars are connected, in particular, to the pivotable mouth part, are arranged in said mouth part or form the pivotable mouth part.
As an alternative to this, the arms or bars are connected in a rigid manner to the basic body of the tool, and the axial pins engage in recesses which are provided on the pivotable mouth part.
In the case of a tool with two axial pin components, as is described here, the axial pin components have been connected together in a rigid manner once the axial pins have been inserted into the corresponding recesses.
In particular, once the axial pins have been inserted in the corresponding recesses, the already mentioned arms or bars have been joined together directly or indirectly in order to form, for example, the pivotable mouth part.
In the case of a tool with axial pin components which have been connected together in a rigid manner once the axial pins have been inserted in the corresponding recesses, the axial pin components are connected together in a rigid manner, in particular, by means of a basic body of the pivotable mouth part.
In particular, the mentioned arms or bars of the axial pin components are inserted into bores or grooves in the basic body of the pivotable mouth part and are joined.
A tool, as is described here, includes additionally, in particular, a transferring device for transferring a force to the tool, wherein the transferring device and the pivotable mouth part have curved sliding faces which abut against one another and are realized for the purpose of coupling a translation movement of the transferring device with a pivoting movement of the pivotable mouth part, wherein a center of curvature of the curved sliding faces lies outside the tool.
The transferring device is slidable, in particular, lengthwise of a shaft which is couplable to the tool or is connected in a permanent manner. The transferring device can be coupled in such a manner with the mouth part by means of the curved sliding faces, which abut against one another, that a movement of the transferring device in the proximal direction brings about a closing pivoting movement of the mouth part or, as an alternative to this, in a reverse manner brings about an opening movement of the mouth part. The transferring device, in this case, is guided, in particular, inside the tool or inside a shaft which is couplable with the tool or is permanently connected to the tool, such that it is slidable along a substantially straight or slightly curved path.
The sliding faces of the transferring device and of the pivotable mouth part, in each case abutting against one another in pairs, have, in particular, a common center of curvature or are rotationally symmetrical with respect to an axis. Said substantially arcuate development of the sliding faces enables flat contact which can be suitable for transferring large forces.
As an alternative to this, the sliding faces can have several centers of curvature or a varying curvature or a development which is not rotationally symmetrical with respect to an axis. With said resultant non-arcuate development of the sliding faces, a varying transformation ratio can be realized between the movement of the transferring device and the pivoting movement of the pivotable mouth part.
The arrangement of the center of curvature of the curved sliding faces makes possible a large transformation ratio where a translation movement of the transferring device along a relatively long path is necessary for a predetermined pivoting movement of the pivotable mouth part.
In the case of a tool with curved sliding faces, abutting against one another, on the transferring device and the pivotable mouth part, as is described here, in particular the curved sliding faces on the mouth part are parallel faces on a curved groove and the curved sliding faces on the transferring device are parallel faces on a curved web. As an alternative to this, the curved sliding faces on the mouth part can be parallel faces on a curved web and the curved sliding faces on the transferring device can be parallel faces on a curved groove. As an alternative to this, the curved sliding faces can be non-parallel.
In the case of a tool, as is described here, the pivot axis about which the pivotably mounted mouth part is pivotable lies in particular inside the tool.
An arrangement of the pivot axis inside the tool refers to the fact that the pivot axis intersects or penetrates the volume assumed by the tool. In other words, a portion of the pivot axis lies inside the contour of the tool.
In the case of a tool, as is described here, a groove is provided inside a circular cylindrical region of space, in particular, on at least one of the two axial pins, wherein the radial surface of the axial pins lies on a radial surface of the circular cylindrical region of space.
Side walls of the groove lying opposite one another form, in particular, the mentioned curved sliding faces on the pivotable mouth part. In particular, a web on the mentioned transferring device engages in the groove.
A medical instrument includes a tool, as is described here.
Embodiments are explained below by way of the accompanying figures, in which, in detail:
Two parts of the handling device 15 are movable in relation to one another. One of the two parts is connected in a rigid manner to the tool 40 by means of the shaft 20, the other part of the handling device 15 is coupled with a pivotable mouth part 42 of the tool 40 by means of a transferring device (in particular a transferring rod) which is arranged in the shaft 20. A manually activated relative movement of the two parts of the handling device 15 results in a corresponding relative movement of the pivotable mouth part 42 in relation to a fixed mouth part 41 of the tool 40.
The tool 40 is coupled mechanically with the distal end 22 of a shaft 20 so as to be detachable or is permanently connected thereto. The tool 40 includes a fixed mouth part 41 and a pivotable mouth part 42. The fixed mouth part 41 is arranged in a rigid manner in relation to the shaft 20. The pivotable mouth part 42 is pivotable in relation to the fixed mouth part 41 about a pivot axis 48 at right angles with respect to the drawing plane of
A first axial pin component 60 and a second axial pin component 70 are realized in a mirror symmetrical manner with respect to one another and are connected to the basic body 50 so as to be pivotable. Features of the bearing arrangement of the axial pin components 60, 70 on the basic body 50 are described in more detail below with reference to
A transferring device 30 extends in the shaft 20 (cf.
A sleeve 45 is arranged on the proximal end of the basic body 50. The sleeve 45, in the example shown, has cross section which varies in a step-shaped manner. The sleeve 45 surrounds the transferring device 30 or the bars 33, 34 thereof in a ring-shaped manner. A coupling for the detachable mechanical coupling of the tool 40 with a distal end 22 of a shaft 20 (cf.
Each bar 33, 34 has a curved web which engages in a curved groove on one of the axial pin components 60, 70. Said webs on the bars 33, 34 and the grooves on the axial pin components 60, 70 cannot be seen in
The axial pins 63, 73 can be inserted into the recess 53 on the basic body 50 by means of insertion movements 61, 71, indicated by means of arrows, parallel to the pivot axis 48. The recess 53 has a circular cross section which is tuned in such a manner to the radial surfaces 64, 74 of the axial pins 63, 73 that the axial pins 63, 73, once they have been inserted 61, 71 into the recess 53, are guided on the basic body low in play and friction. The recess 53 in the basic body 50 and the axial pins 63, 73 engaging in the recess 53 form the joint or bearing 43 which has already been indicated in
A curved groove 65 can be seen in the first axial pin component 60 in
A curved web 35 with a first sliding face 36 and a second sliding face 37 can be seen on the second bar 34 on the distal end of the transferring device 30. The first bar 33 has a web which is curved in a mirror-symmetrical manner to the curved web 35 on the second bar 34. The widths and the curvatures of the curved grooves 65 on the axial pin components 60, 70 and the widths and the curvatures of the webs 35 on the bars 33, 34 of the transferring device 30 correspond to one another such that the webs 35 on the bars 33, 34 are guided low in play and friction in the grooves 65 on the axial pin components 60, 70 when the distal end of the transferring device 30 is inserted into the basic body 50 and the axial pin components 60, 70.
After inserting the axial pins 63, 73 into the recess 53 in the basic body 50 and coupling the bars 33, 34 with the axial pin components 60, 70 by inserting the curved web 35 into the curved groove 65, the bars 62, 72 of the axial pin components 60, 70 are connected together by a basic body (not shown in
The cutting planes of
The design of the basic body 50 with the base plate 51 arranged horizontally in
In addition, it can be seen how the axial pins 63, 73 engage in the longitudinal webs 56, 57 of the basic body 50. In this case,
In addition, the basic body 46, already mentioned in the description of
Number | Date | Country | Kind |
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10 2012 007 647.9 | Apr 2012 | DE | national |