DE102021123881A1 - Micro-invasive tool for a micro-invasive medical instrument - Google Patents

Abstract

A micro-invasive tool (30) for a micro-invasive medical instrument comprises a guide device (40) which is mechanically rigidly connected or can be connected to a distal end of a shaft (20) of the micro-invasive medical tool (10), a first jaw part (50) which is mechanically connected to the guide device (40), a second jaw part (60) and a guide pin (46) for the pivotable mechanical connection of the second jaw part (60) to the guide device (40). The guide pin (46) is either rigidly connected to the guide device (40) and slidably guided in a slot (76) in the second jaw part (60) or rigidly connected to the second jaw part (60) and guided in a slot (74) in the Guide device (40) slidably guided.

Description

The present invention relates to a micro-invasive tool for a micro-invasive medical instrument and to a micro-invasive medical instrument with such a micro-invasive tool, the tool being in particular a gripping, cutting, punching or squeezing tool.

Gripping, cutting, punching or squeezing tools for gripping, cutting, punching or squeezing tissue have several jaw parts or branches, usually two jaw parts. The jaw parts can be moved, in particular pivoted, relative to one another. In the case of tools that open easily, one jaw part is rigidly connected to the shaft of the microinvasive instrument, and the second jaw part can be pivoted about a predetermined pivot axis. Alternatively, both jaw parts can be pivoted about the same pivot axis or about two different pivot axes.

The mechanical control of the pivotable jaw part or parts is usually carried out by a pull rod, which is mounted in a shaft of the medical instrument so that it can move in its longitudinal direction. The drawbar connects a pivotable handle portion of a manipulation device at the proximal end of the instrument to the jaw portion of the tool at the distal end of the instrument. At its distal end, the tie rod acts in particular as a connecting rod for coupling a linear translational movement with a pivoting movement of a mail part. A simple articulated connection of the distal end of the pull rod to the pivotable jaw part results in bending deformation and/or displacement of the pull rod in the shaft in a direction orthogonal to its longitudinal extent when the jaw part is pivoted.

Various approaches try to avoid the displacement of the pull rod orthogonal to its longitudinal direction and/or the bending deformation of its distal end area during pivoting of the jaw part. One solution is to use an elongated hole at the distal end of the drawbar, another solution is to use a second joint proximal to the distal end of the drawbar. Both solutions have specific disadvantages, which become more apparent as the miniaturization of microinvasive instruments progresses. A bipolar design of the tool with the requirement for electrical insulation complicates the construction in addition.

An object of the present invention is to provide an improved micro-invasive tool for a micro-invasive medical instrument.

This object is solved by the subject matter of the independent claim.

Further embodiments are defined in the dependent claims.

A micro-invasive tool for a micro-invasive medical instrument comprises a guide device which is mechanically rigidly connected or connectable to a distal end of a shaft of the micro-invasive medical tool, a first jaw part which is mechanically connected to the guide device, a second jaw part and a guide pin for pivoting mechanical connection of the second jaw part to the guide device, with the guide pin either being rigidly connected to the guide device and movably guided in a slot in the second jaw part or rigidly connected to the second jaw part and movably guided in a slot in the guide device.

The micro-invasive tool is in particular a gripping, cutting, punching or squeezing tool for gripping, cutting, punching or squeezing tissue or other objects. The micro-invasive tool is intended and designed in particular for a micro-invasive medical instrument with a long, thin shaft and a handling device at the proximal end of the shaft. The micro-invasive tool, in particular the proximal end of the guide device, can be a fixed, ie permanent, part of a micro-invasive medical instrument. Alternatively, the micro-invasive tool can be provided and designed for a permanent mechanical connection to a distal end of a shaft and/or another component of a micro-invasive medical instrument. Alternatively, the micro-invasive tool can be provided and designed for non-destructively releasable mechanical connection to a distal end of a shaft or to another component of a micro-invasive medical instrument.

The guide device is designed in particular as a fork-shaped component or a component that is forked in one area with two or more bar-shaped areas arranged in parallel. Distal to a bifurcated area, the guide device can merge into the first jaw part. If the guide pin is arranged in a forked area of the guide device, in particular its two ends are fastened to or in a bar-shaped area of the guide device or are each mounted in a slot. The second jaw part is in the bifurcated area of the guiding device through the guiding pin with the guiding device articulated, namely pivotally connected about a pivot axis defined by the guide pin.

The guide pin, also referred to as the main rivet, extends in particular in a direction orthogonal to the main extension directions of the jaw parts and optionally orthogonal to a longitudinal axis of a distal end area of a shank connected to the tool. The guide pin may have a circular or other cross-section. The cross section of the guide pin can be constant or can vary in the longitudinal direction of the guide pin. The guide device and the guide pin reduce the number of degrees of freedom of the second jaw part in particular to two, namely a rotary degree of freedom about the pivot axis defined by the guide pin and a translatory degree of freedom along a path defined by the slot or slots.

A microinvasive tool, as described here, also includes in particular a force transmission device with a distal end area and a force transmission joint between the distal end area of the force transmission device and the second jaw part, the distal end area of the force transmission device being guided in the guide device with little play and little friction in order to to force movement of the transmission joint along a straight path.

A proximal end of the force transmission device is mechanically coupled or can be coupled to a pivotable handle part of a handling device on a proximal end of the microinvasive medical instrument. The force transmission device is in particular a pull rod, with a movement of the pull rod in the proximal direction causing the jaw parts to close, namely the second jaw part to pivot towards the first jaw part. In this case, the distal end area of the force transmission device is also referred to as a pulling attachment. Alternatively, the force transmission device can be coupled to the second jaw part or to both jaw parts in such a way that a distal movement of the force transmission device is accompanied by a closing of the jaw parts, namely a pivoting of the second jaw part towards the first jaw part.

In particular, the power transmission joint has precisely one degree of freedom. The power transmission joint is formed, for example, by a pin or bolt, which is also referred to as a plug-in rivet. The pin or bolt can be mechanically rigidly connected to the distal end area of the force transmission device and guided in a recess in the second jaw part with little play and little friction. Alternatively, the pin or bolt can be mechanically rigidly connected to the second jaw part and guided in a recess in the distal end area of the force transmission device with little play and little friction.

The low-backlash and low-friction guidance of the distal end region of the force transmission device in the guide device allows movement of the power transmission joint only along a straight path, which is defined by the low-backlash and low-friction guidance of the force transmission device in the guide device. In particular, the path is parallel to the longitudinal axis of the power transmission device.

With the displaceability of the second jaw part relative to the guide device along the path defined by the slot or slots and the guidance of the force transmission joint along a straight path, part of the second jaw part can be prevented from escaping from a contour of the guide device during pivoting. At the same time, the force transmission device can be made mechanically more robust and the force transmission joint can be made smaller.

In the case of a micro-invasive tool, as is described here, the distal end area of the force transmission device is designed to be mechanically rigid, in particular.

A mechanically rigid design is a design in which the forces occurring during the intended use do not cause any significant elastic or plastic deformation of the distal end region. In particular, the distal end portion is deformed in a direction orthogonal to the longitudinal axis of the power transmission device by no more than one twentieth, no more than one fiftieth, or no more than one hundredth the diameter of the tool in its closed configuration.

In a micro-invasive tool as described here, the elongated hole extends, in particular at least in a closed configuration of the tool, essentially in a direction orthogonal to a direction of movement of the force transmission device.

The elongated hole extends essentially orthogonally to a direction of movement of the force transmission device when the angle between the path defined by the elongated hole along which the guide pin is movable in the elongated hole and the direction of movement of the force transmission device is at least 60°. If the slot is provided in the guide device hen, this angle is constant, ie independent of the pivoting position of the second jaw part. If the elongated hole is provided in the second jaw part, the direction in which it extends depends on the pivoting position of the second jaw part. The elongated hole may be formed so that it extends orthogonally or substantially orthogonally to the direction of movement of the power transmission device only in the closed configuration. Alternatively, the elongated hole can be designed in such a way that the direction in which it extends always encloses an angle of at least 60° with the direction of movement of the force transmission device.

In a micro-invasive tool as described here, the first jaw part has, in particular, a first electrically conductive surface area, the second jaw part has a second electrically conductive surface area, and the first electrically conductive surface area on the first jaw part differs from the second electrically conductive one Surface area is electrically isolated on the second jaw part.

Each of the two jaw parts can be made entirely of an electrically conductive material, in particular surgical stainless steel and/or one or more other metals. Alternatively, each of the two jaw parts can be partially formed from plastic or another electrically insulating material. The electrically conductive surface areas of the jaw parts can be used as electrodes and enable the micro-invasive tool to be used as a bipolar electrosurgical tool. In this case, for example, a first electrical potential is applied to the first jaw part via the shaft and a second electrical potential is applied to the second jaw part via the pull rod.

The mechanically simple connection of the force transmission device to the second jaw part via the force transmission joint can avoid contact problems and enable reliable supply of the electrical potential to the second jaw part.

In the case of a micro-invasive tool, as is described here, the first jaw part is connected to the guide device in a particularly mechanically rigid manner.

The first jaw part is in particular designed in one piece with the guide device.

In the case of a micro-invasive tool, as is described here, the first jaw part is mechanically connected to the guide device, in particular so that it can pivot about a predetermined axis.

In this case, therefore, both jaw parts can be pivoted about the same axis or about two, in particular parallel, axes. Both jaw parts are in particular coupled to the same force transmission device in such a way that they can be moved synchronously in opposite directions. Alternatively, several power transmission devices can be provided, which are each coupled to a jaw part in order to control them independently.

In a micro-invasive tool as described here, in particular either the first jaw part is mechanically pivotably connected to the guide device by the guide pin or the first jaw part is mechanically pivotably connected to the guide device or to the second jaw part by a further guide pin.

As mentioned, in particular, both jaw parts are coupled to the same force transmission device, namely in an articulated manner, in order to move both jaw parts synchronously.

A micro-invasive medical instrument includes a micro-invasive tool as described herein.

character list

• 1 eine schematische Darstellung eines mikroinvasiven medizinischen Instruments;
• 2 eine schematische Darstellung eines Schnitts durch ein Werkzeug am distalen Ende des mikroinvasiven Instruments aus 1;
• 3 eine schematische Darstellung eines weiteren Schnitts durch das Werkzeug aus 2;
• 4 eine schematische Darstellung eines weiteren Schnitts durch das Werkzeug aus den 2 und 3;
• 5 eine schematische Darstellung eines weiteren Werkzeugs;
• 6 eine weitere schematische Darstellung des Werkzeugs aus 5;
• 7 eine schematische Darstellung eines weiteren Werkzeugs.

Embodiments are explained in more detail below with reference to the attached figures. Show it:

• 1 a schematic representation of a microinvasive medical instrument;
• 2 a schematic representation of a section through a tool at the distal end of the microinvasive instrument 1 ;
• 3 a schematic representation of a further section through the tool 2 ;
• 4 a schematic representation of a further section through the tool from the 2 and 3 ;
• 5 a schematic representation of another tool;
• 6 Another schematic representation of the tool 5 ;
• 7 a schematic representation of another tool.

Description of the embodiments

1 12 shows a schematic representation of a micro-invasive medical instrument 10. A proximal end 12 of the micro-invasive medical instrument 10 is formed by a handling device 14. FIG. With the one shown For example, the handling device 14 has a stationary handle part and a movable handle part 16, which can be pivoted with the thumb, for example.

The handling device 14 at the proximal end 12 is connected to a distal end 18 of the microinvasive medical instrument 10 by a shaft 20 . In the example shown, the shank is straight and rigid. Deviating from this, the shaft 20 can be partially or completely curved and/or partially or completely flexible.

The distal end 23 of the shaft 20 is mechanically rigidly connected to a tool 30, the design of which is described below with reference to the other figures. The tool 30 can be connected to the distal end 23 of the shank 20 permanently, ie not detachably connected non-destructively, for example by a welded or adhesive connection. Alternatively, the tool 30 can be connected to the distal end 23 of the shaft 20 in a non-destructively detachable manner, for example by means of a bayonet connection (often also referred to as a bayonet connection) or a screw connection.

2 shows a schematic and significantly enlarged representation of a section through an embodiment of the tool 30 at the distal end 23 of the shank 20 based on FIG 1 illustrated microinvasive medical instrument. The cutting plane of 2 is parallel to the plane of the drawing 1 and contains the longitudinal and symmetry axis 28 of the shaft 20 at its distal end 23.

The tool 30 includes a bifurcated guide assembly 40 having a coupling assembly 42 at the proximal end thereof. In the example shown, the coupling device 42 is through in the sectional plane 2 lying and outwardly projecting lugs are formed, which engage in corresponding L-shaped grooves on the inside of the distal end 23 of the shaft 20 .

A bifurcated area 44 of the guide device 40 is formed by two parallel and bar-shaped sections with approximately circular segment-shaped cross-sections, of which one in front of and one behind the cutting plane of the 2 lies. A guide pin 46 extends in the direction orthogonal to the sectional plane of the 2 . One end of the guide pin 46 is mechanically rigidly connected to one of the two beams that form the forked area 44 of the guide device 40 . In the example shown, the guide pin 46 has a circular cross-section.

The tool 30 has a first jaw part 50 which, in the example shown, is rigidly connected to the guide device 40, namely is designed in one piece and is connected distally to the forked area 44. The guide device 40 and the first jaw part 50 are made of metal and are therefore electrically conductive. Therefore, the gripping surface of the first jaw part 52 in particular forms an electrically conductive surface area 52 of the first jaw part 50.

The tool 30 also includes a second jaw part 60. The second jaw part 60 is also made of metal and is therefore electrically conductive. The gripping surface of the second jaw part 60 forms an electrically conductive surface area 62 of the second jaw part 60. Near the proximal end of the second jaw part 60 there is a slot 76 in which the guide pin 46 is arranged. The cross section (in the example shown: circular) of the guide pin 46 and the cross section of the slot 76 correspond in such a way that the guide pin 46 is guided in the slot 76 with little play and little friction. Together with the guidance of the second jaw part 60 between the beams forming the forked area 44 of the guide device 40, two degrees of freedom of the relative movement remain. The second jaw part 60 can be pivoted relative to the guide device 40 about the guide pin 46 - more precisely: about the axis of symmetry of its rotational symmetry - and can be displaced along a path which is defined by the cross sections of the elongated hole 76 in the second jaw part 60 and of the guide pin 46.

A pull rod 80 as a force transmission device extends in the shaft 20 from the proximal end 12 of the microinvasive medical instrument 10 (cf. 1 ) to the tool 30. A distal end region 84 of the pull rod 80 is connected in an articulated manner to the second jaw part 60 by a force transmission joint 86. The power transmission joint 86 is formed, for example, by a pin, also referred to as a plug-in rivet, which is mechanically rigidly connected to the second jaw part 60 and guided with little play and friction in a corresponding bore in the distal end region 84 of the pull rod 80 or vice versa. The power transmission joint 86 allows pivoting of the second jaw part 60 relative to the distal end portion 84 of the pull rod 80 to the cutting plane of the 2 orthogonal axis.

The pull rod 80 and its distal end area 84 are guided in a corresponding bore in the guide device 40 with little play and little friction. The pull rod 80 and its distal end portion 84 are therefore relative to the guide device 40 only in a direction parallel to the longitudinal and symmetrical axis 28 of the shaft 20, the is at the same time the longitudinal axis of the power transmission device 80, movable. The distal end area 84 of the pull rod 80 is designed to be mechanically stiff, so that the force-transmission joint 86 can only be moved along a straight path 96 . A translation of the force transmission device 80 is therefore not only associated with a pivoting movement of the second jaw part 60 but also with a translation of the guide pin 46 within the elongated hole 76 .

3 shows another schematic representation of the tool 2 . The type of representation, in particular the cutting plane of the 3 corresponds to that of 2 .

In 3 is one of the in 2 shown configuration deviating configuration shown. Opposite the in 2 configuration shown are - in particular by a manual pivoting of the movable grip part 16 at the proximal end 12 of the micro-invasive medical instrument 10 (cf. 1 ) the force transmission device 80 is displaced proximally and the second jaw part 60 is pivoted toward the first jaw part 50. in the in 3 In the configuration shown, the guide pin 46 assumes a different position within the elongated hole 76 in the second jaw part 60 .

4 shows a schematic representation of a section through the tool from FIGS 2 and 3 in another configuration. The type of representation, in particular the section plane corresponds to that of 2 and 3 .

In 4 another, closed configuration is shown. The force transmission device 80 assumes an extremely proximal position, the jaw parts 50, 60 rest against one another. The guide pin 46 again assumes a different position within the elongated hole 76 in the second jaw part 60 .

5 FIG. 12 shows a schematic representation of an alternative embodiment of the tool 30 of the microinvasive medical instrument 10. FIG 1 . In the 5 The embodiment shown is similar in some features, properties and functions based on the 2 until 4 illustrated embodiment. In particular, the features, properties and functions of the in 5 shown embodiment, in which these differ from the basis of 2 until 4 shown embodiment is different, described. The character level of 5 is parallel to the plane of the drawing 1 and the cutting planes of 2 until 4 . However, the tool is 30 in 5 not shown in section. Components which are arranged inside the tool 30 or the shaft 20 and are therefore not visible per se are shown in dashed lines.

This in 5 Tool 30 shown differs from that based on FIG 2 until 4 Tool shown in particular in that the guide pin 46 is mechanically rigidly connected to the second jaw part 60. The ends of the guide pin 46 are each guided in a slot 74 in each of the two parallel bars that form the forked area 44 . The guide pin 46 can therefore be displaced relative to the guide device 40 together with the second jaw part 60 .

5 shows a first configuration, which is based on the 2 configuration shown. The guide pin 46 assumes a first position within the elongated holes 74 .

6 FIG. 12 shows a schematic representation of another configuration of the tool 30 from FIG 5 . The type of representation, in particular the character level of the 6 corresponds to that of 5 .

In the 6 configuration shown corresponds to that in 3 shown configuration. Opposite the in 5 Configuration shown are those in 6 force transmission device shown in dashed lines is shifted proximally and the second jaw part 60 is pivoted toward the first jaw part 50 . The guide pin 46 assumes a different position within the slot 74 in the guide device 40 .

7 shows a schematic representation of a section through a further embodiment of the tool from the 2 until 4 . The type of representation corresponds to that of 2 until 4 .

In the 7 shown embodiment differs from the basis of 2 until 4 illustrated embodiment in particular by a different arrangement of the force transmission joint 86 relative to the slot 76 in the second jaw part 60 and by a slightly different orientation of the slot 76. The tool 30 is in the basis of 4 configuration shown.

In this configuration, the guide pin 46 is arranged in the second jaw part 60 at the end of the elongated hole 76 facing the force transmission joint 86 . The second jaw part 60 can therefore not be displaced away from the first jaw part 50 by an elastic restoring force of tissue squeezed between the jaw parts 50, 60.

Reference List

10

microinvasive medical instrument

12

proximal end of the microinvasive instrument 10

14

Handling device at the proximal end 12 of the microinvasive instrument 10

16

movable handle part of the handling device 14

18

distal end of the microinvasive instrument 10

20

Shaft of the microinvasive medical instrument 10

23

distal end of shaft 20

28

Longitudinal and symmetrical axis of the shaft 20 at its distal end 23

30

tool at the distal end 23 of the shaft 20

40

Guide device of the tool 30

42

Coupling device for non-destructively releasable mechanical connection to the distal end 23 of the shaft 20

44

bifurcated area of the guiding device 40

46

Guide pin for the pivotable mechanical connection of the second jaw part 60 to the forked area 44 of the guide device 40

50

first jaw part of the tool 30

52

first electrically conductive surface area on the first jaw part 50

60

second jaw part of the tool 30

62

second electrically conductive surface area on the second jaw part 60

74

Slot in the guide device 40

76

Slot in the second jaw part 60

80

Drawbar as power transmission device

84

distal end area of the pull rod 80

86

Power transmission joint between the pull rod 80 and the second jaw part 60

96

Transmission joint path 86

Claims (9)

Micro-invasive tool (30) for a micro-invasive medical instrument (10), with: a guide device (40) which is mechanically rigidly connected or can be connected to a distal end of a shaft (20) of the microinvasive medical tool (10); a first jaw part (50) which is mechanically connected to the guide device (40); a second jaw part (60); a guide pin (46) for the pivotable mechanical connection of the second jaw part (60) to the guide device (40), wherein the guide pin (46) is either rigidly connected to the guide device (40) and guided displaceably in a slot (76) in the second jaw part (60) or rigidly connected to the second jaw part (60) and guided in a slot (74) in the Guide device (40) is slidably guided. A microinvasive tool (30) according to the preceding claim, further comprising: a power transmission device (80) having a distal end portion (84); a force transmission joint (86) between the distal end area (84) of the force transmission device (80) and the second jaw part (60), wherein the distal end area (84) of the force transmission device (80) is guided in the guide device (40) with little play and friction in order to force a movement of the force transmission joint (86) along a straight path (96). Micro-invasive tool (30) according to the preceding claim, in which the distal end region (84) of the force transmission device (80) is mechanically rigid. Micro-invasive tool (30) according to one of claims 2 and 3 , in which the elongated hole (74, 76) extends substantially in a direction orthogonal to a direction of movement (28) of the force transmission device (80), at least in a closed configuration of the tool (30). Micro-invasive tool (30) according to any one of the preceding claims, wherein the first jaw part (50) has a first electrically conductive surface area (52), the second jaw part (60) has a second electrically conductive surface area (62), the first electrically conductive surface area (52) on the first jaw part (50) is electrically insulated from the second electrically conductive surface area (62) on the second jaw part (60). Micro-invasive tool (30) according to one of the preceding claims, in which the first jaw part (50) is mechanically rigidly connected to the guide device (40). Micro-invasive tool (30) according to one of Claims 1 until 5 In which the first jaw part (50) is mechanically connected to the guide device (40) so that it can be pivoted about a predetermined axis. Microinvasive tool (30) according to the preceding claim, in which either the first jaw part is pivotably connected mechanically to the guide device (40) by the guide pin (46). or the first jaw part is pivotably mechanically connected to the guide device (40) or to the second jaw part (60) by a further guide pin. Micro-invasive medical instrument (10) with a micro-invasive tool (30) according to one of the preceding claims.

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