GB2038640A

GB2038640A - Cutting device

Info

Publication number: GB2038640A
Application number: GB7943712A
Authority: GB
Original assignee: Draegerwerk AG and Co KGaA
Current assignee: Draegerwerk AG and Co KGaA
Priority date: 1978-12-22
Filing date: 1979-12-19
Publication date: 1980-07-30
Also published as: DE2855655A1; FR2444454A1

Abstract

A cutting device suitable for human or animal tissue has a first member (1) with a first cutting edge (5) and a second member (3) with a second cutting edge (9), the second member (3) being mounted around the first member (1) for relative translational and rotational movement therewith. A mechanical coupling means (11) couples the two members (1) and (3) together. In use, with the first and second cutting edges (5) and (9) initially spaced apart both translationally and angularly and with a piece of tissue adjacent the first cutting edge (5), the second member can be displaced translationally and rotationally relative to the first member until the first and second cutting edges between them cut the tissue. <IMAGE>

Description

SPECIFICATION Cutting device for human or animal tissue This invention relates to a cutting device suitable for cutting human or animal tissue, for example tissue adhesions.

Cutting devices for severing tissue must allow cutting to be carried out in confined conditions whilst not affecting the surround tissue as fas as is possible. It should be possible to carry out the cutting operation in a controlled, swift and reliable manner in order that the patient is affected as little as possible.

A known medical apparatus described in German Patent Specification 2024961 for cutting tissue inside openings in a body comprises an instrument which has a heat exchanger, is capable of being cooled or heated in a selective manner, and has a hook for taking hold of the tissue to be cut or removed. The instrument is arranged inside a tubular shell such that it is capable of longitudinal movement, which tubular shell has a handle at its end and encloses at the other end the instrument as far as the hook. A seal between instrument and tubular shell is intended to prevent any moisture entering therebetween. The instrument and the tubular shell can be mutually displaced in a longitudinal direction against a spring by means of a toggle lever operated externally. A web of tissue to be severed is taken hold of by the hook and frozen by cooling.This web of tissue is then drawn by the hook into the tubular shell by operating the toggle lever. By this action, the front faces of the tubular shell in contact with the lateral faces of the hook cut off the web of tissue taken. The apparatus is then ready for further use by subsequently heating the instrument. This has the disadvantage that moisture penetrates between the instrument and the tubular shell from the hook side with the danger of the apparatus freezing fast, with the result that the parts cannot be moved relatively for severing the tissue to be removed. Also, owing to the fixed size of the hook and of the tubular shell, the size of the tissue cut off is fixed for every cut; any adaptation or variation is not possible.

In order to obtain an improved shearing effect, it is known to construct the apparatus with a specific cutting edge which slides along the hook. Such an apparatus is disclosed in German Patent Specification 22 013. The cutting edge is secured to a tube interposed concentrically between apparatus part and tubular shell. The hook has a point at its front end. Flat adhesions are perforated by the point prior to the actual severing process. This known apparatus does not constitute any decisive improvement in comparison to the previously mentioned apparatus.

According to the present invention there is provided a cutting device suitable for cutting human or animal tissue, the device comprising: a first member one end region of which is provided with a first cutting edge and with heating and cooling means for heating and cooling tissue adjacent the first cutting edge; a second member which is mounted around the first member for relative translational and rotational movement therewith, one end region of the second member being provided with a second cutting edge; and mechanical coupling means coupling the first and second members; the arrangement of the device being such that, with the first and second cutting edges initially spaced apart both translationally and angularly and with a piece of tissue adjacent the first cutting edge, the second member can be displaced translationally and rotationally relative to the first member until the first and second cutting edges between them cut the tissue. With the arrangement of the cutting edge on the circumference of the apparatus it is possible to reach and take hold of the tissue to beyservered in a simple manner. There is a thermal connection between the cutting edge of the first member and the heating and cooling means, thus allowing the cooling and also the subsequent heating of the tissue to be effected in a swift and uniform manner.As the second member is capable of translational and rotational displacement, the second member is located with its cutting edge in an area which is not affected by the cooling operation and remains movable. The rime produced by the cooling operation can be shaved off by the second member as the cutting edges are moved towards one another. The cutting action can be smooth and give vibration-free execution, and thus prevents the patient from being adversely affected.

Operation is also possible without the freezing process.

Preferably, the first member is cylindrical and the second member is tubular; and the first member is further provided with a first curved edge one end region of which meets the first cutting edge to define therewith an acute angle, andlor the second member is further provided with a second curved edge one end region of which meets the second cutting edge to define therewith an acute angle.

Preferably the mechanical coupling means comprises: a pivot member pivotally mounted with respect to the first member about a first pivot axis which is perpendicular to the axes of the first and second members; and a connecting member one end of which is pivotally mounted with respect to the pivot member about a second pivot axis which is perpendicular to and optionally displaced from the first pivot axis, and the other end of which is connected to the second member by a ball and socket or like joint; the arrangement being such that, with the second pivot axes initially parallel to axes of the first and second members, the first and second cutting edges are spaced apart both translationally and angularly from one another, and with the pivot member then being rotated about the first pivot axis, the second member is displaced translationally and rotationally to cause the first and second cutting edges to approach each other.

Such construction of the mechanical coupling means allows the second member to effect a movement whose rotational portion increases as the movement progresses, with the result that, after an initially time-saving, rapidtranslational movement, the cutting edges are closed by a movement which is mainly rotational so that the cutting edges are urged towards one another. The apparatus can be such that dismantling for cleaning and disinfecting pur poses is straight forward.

The device can also include means for applying a torque to the pivot member to rotate the pivot member about the first pivot axis. The means for applying a torque can comprise a first handle associated with the first member and a second handle integral with or fixed to the pivot member.

Alternatively the means for applying the torque comprises a projection of the pivot member perpendicular to the first pivot axis.

Preferably a free end region of the projection remote from the first pivot axis is acted upon by an axially displaceable sleeve slidably located around the first member.

The mechanical coupling means in a second embodiment comprises a projection extending radially from the first member, which projection engages a curved slot in the second member.

Preferably the mechanical coupling means is such that, while the second member is being displaced from a position in which the first and second cutting edges are spaced apart, the movement of the second member is initially mainly translational with relatively little rotational movement, but as the first and second cutting edges approach one another the movement of the second member becomes mainly or wholly rotational with relatively little or no translational movement.

The first and second cutting edges can be straight and parallel and parallel to the axes of the first and second members. In a variant embodiment, one or both of the first and second cutting edges can be concave. In a further variant embodiment both of the first and second cutting edges are straight and are such that, when one end of the first cutting edge is adjacent a corresponding end of the second cutting edge, an acute angle is included between the two cutting edges.

For a better understanding of the present invention and to show more clearly how the same may be carried into effect, reference will now be, by way of example, to the accompanying drawings in which: Figure 1 shows a perspective view of a cutting device according to the present invention; Figure 2 shows an end of the device of Figure 1 with the cutting edges in a cutting position; Figure 3 shows an axial section through the end of a first member of the device; Figure 4 shows an alternative embodiment of the mechanical coupling means of the device; Figure 5 shows a further embodiment of the mechanical coupling means; Figure 6 shows a first variant embodiment of the cutting edges; and Figure 7 shows a second variant embodiment of the cutting edges.

The device shown in Figure 1 comprises a first member 1 having a cylindrical shape, which is provided with a handle 2, and a second member 3 which is tubular and surrounds a portion of the first member 1 such that the first and second members 1 and 3 are capable of rotational and axial movement relative to one another. An end 4 of the first member 1 1 is provided with a cutting edge 5 extending parallel to the main axis 7 of the device. A curved edge 6, which is at least partially helicoidal, connects the two ends of the cutting edge 5.The distal end region 6A of the curved edge 6 defines with the cutting edge 5 an acute angle, The second member3 is similarly provided with a cutting edge 9 at its end 8, which edge 9 is intended to co-operate with the cutting edge 5 of the first member 1 and also extends para llel to the main axis 7 of the device, A curved edge 10 of the second member 3 is at least partially helicoidal and connects the ends of the cutting edge 9. The distal end region 1 OA of the curved edge 10 defines with the cutting edge 9 an acute angle. A mechanical coupling means generally indicated by the reference' numeral 11 couples the two members 1 and 3 togehter.

The mechanical coupling means 11 comprises two pivot joints 12 and 16 and a ball and socket joint 20.

A pivot shaft 14 of the first pivot joint 12 is secured to the first member 1. The first axis of the first pivot joint 12 is perpendicular to the main axis 7, and also to a second axis 17 of the second pivot joint 16. The pivot joints 12 and 16 are provided partially by a pivot member 13 comprising two bushes 15 and 18.

The pivot shaft 14 is located in a first bore in the bush 15. A connecting member 19 connects the second pivot joint 16to the ball and socket joint 20. One end of the connecting member 19 pivots in a second bore in the bush 18 and the other end of the connecting member 19 bears the socket of the joint 20. The ball of the joint 20 is connected to a flange 21 secured to the third member 3. A spring (not shown) is provided between the first member 1 and the bush 15; the spring urges the bush 15 clockwise so that the device is maintained in a rest position in which the cutting edges 5 and 9 are spaced apart from one another. An operating element 22 in the form of a second handle is secured to the pivot member 13. If the operating element 22 is moved anti-clockwise, joint 20 describes the line of motion 23.In this connection the second member 3 executes a helicoidal movement relative to the first member 1, at the end of which movement the cutting edge 9 arrives at the cutting edges, as shown in Figure 2. The movement of the second member 3 commenceswith a mainly longitudinal ortranslational displacement with relatively little rotational movemebt, but as the first and second cutting edges 5 and 9 approach one another the movement of the second member 3 becomes mainly rotational with relatively little translational movement.

The interior of the end 4 of the first member 1 is shown in Figure 3. Liquid coolant is supplied to an evaporation chamber25 through a supply tube 26.

The evaporated coolant is then drawn off again through the annular space 27 between the outlet tube 28 and the supply tube 26. A heating unit 29 is arranged inside the evaporation chamber 25; its sup- ply lines are not shown. The heating unit 29 is sup plied either with electricity or a hot fluid. An annular space 30 provides insulation and thereby prevents heat transfer into the interior and also undesirable cooling of the surface of the device except at the end 4.

In use, the end 4 of the device is brought to the place at which tissue is to be severed and the surface of the tissue brought against the cutting edge 5. A portion of the tissue then lies above the cutting edge 5. In this position that tissue is frozen by supplying coolant to the evaporation chamber 25. During the freezing process the first member 3 is disposed with the cutting edge 9 at rest in the non-cooled zone of the first member 1, as shown in Figure 1; any freezing fast is thereby prevented. To cut the tissue, the second member 3 and the cutting edge 9 are moved by manipulating the operating element 22 to urge the cutting edges 5 and 9 together.During the generally helicoidal movement of the cutting edge 9, the edge 9 shaves off the rime produced around the cooled end 4, thereby ensuring that the movement of the second member 3 continues unhindered.

When the movement of the second member 3 is concluded, the tissue taken hold of is severed. After the supply of coolant has been switched off, any adhesions occurring between the frozen pieces of tissue and the still frozen apparatus can be detached by heating the apparatus with the heating unit 29 without causing the patient any pain.

The operating element 22 determines the position of the cutting edges 5 and 9, hence the tissue location to be treated, relative to the hand holding the device.

In the embodiment of Figure 4, the mechanical coupling means 11 includes all the features of the Figure 1 embodiment except for the operating ele- ment 22. In the Figure 4 embodiment, the absence of the operating element 22 enables the whole device to be rotated by as much as 3600 about its own axis relative to a hand of an operator, whilst still leaving the device equally easy to operate regardless of the angular position it adopts. The pivot member 13 is provided with a projection or lever 31 which is moved in the direction of the arrow 33 by a sleeve 32 which is slidably mounted on the first member 1 and is capable of being displaced axially in the direction of the arrow 34. Following a thrust by the sleeve 32, a spring (not shown) pulls back the lever 31 and consequently also the second member 3 into the rest position.The sleeve 32 can have pressure applied over its entire circumference in the direction of the arrow 34 and can thus be displaced axially.

Figure 5 shows a device having a further embodiment of the mechanical coupling means which is generally denoted by the reference numeral 35. The first member 1 has a radially extending projection 37. The second member 3 has a curved slot 38 in which the projection 37 is located. A spring (not shown) between the first member 1 and the second member3 urges the second member3 into the rest position shown. A sleeve 39 abuts a flange 41 of the second member 3. In order to effect a cutting operation the sleeve 39 is urged in the direction of the arrow 40. This action causes the second member 3 to describe a path determined by the shape of the slot 38 until the cutting operation is completed.

Referring to Figure 6, the first and second members 1 and 3 can be provided with respective concave cutting edges 42 and 43. The cutting process may thus commence from the outermost ends of the cutting edges 42 and 43. The concave cutting edges 42 and 43 also help to prevent tissue from slipping out from between the cutting edges. In Figure 7, the cutting edge 44 of the first member 1 and the cutting edge 45 of the second member 3, include an angle which opens towards the outermost end of the apparatus. The cutting action is thereby effected progressively towards the outermost ends of the cutting edges 44 and 45.

Claims

1. A cutting device suitable for cutting human or animal tissue, the device comprising; a first member one end region of which is provided with a first cutting edge and with heating and cooling means for heating and cooling tissue adjacent the first cutting edge; a second member which is mounted around the first member for relative translational and rotational movement therewith, one end region of the second member being provided with a second cutting edge; and mechanical coupling means coupling the first and second members; the arrangement of the device being such that, with the first and second cutting edges initially spaced apart both translationally and angularly and with a piece of tissue adjacent the first cutting edge, the second member can be displaced translationally and rotationally relative to the first member until the first and second cutting edges between them cut the tissue.

2. A device as claimed in claim 1, wherein the first member is cylindrical and the second member is tubular; and wherein the first member is further provided with a first curved edge one end region of which meets the first cutting edge to define therewith an acute angle, andlorthe second member is further provided with a second curved edge one end region of which meets the second cutting edge to define therewith an acute angle.

3. A device as claimed in claim 2, wherein the mechanical coupling means comprises: a pivot member pivotally mounted with respect to the first member about a first pivot axis which is perpendicular to the axes of the first and second members; and a connecting member one of which is pivotally mounted with respect to the pivot member about a second pivotaxiswhich is perpendicular to and optionally displaced from the first pivot axis, and the other end of which is connected to the second member by a ball and socket or like joint; the arrangement being such that, with the second pivot axis initially parallel to axes of the first and second members, the first and second cutting edges are spaced apart both translationally and angularly from one another, and with the pivot member then being rotated about the first pivot axis, the second member is displaced translationally and rotationally to cause the first and second cutting edges to approach each other.

4. A device as claimed in claim 3, which also includes means for applying a torque to the pivot member about the first pivot axis.

5. A device as claimed in claim 4, wherein the means for applying the torque comprises a first handle associated with the first member and a second handle integral with or fixed to the pivot member.

6. A device as claimed in claim 4, wherein the means for applying the torque comprises a projection of the pivot member, perpendicular to the first pivot axis.

7. A device as claimed in claim 6, wherein a free end region of the projection remotefrom the first pivot axis is acted upon by an axially displaceable sleeve slidably located around the first member.

8. A device as claimed in claim 1 or 2, wherein the mechanical coupling means comprises a projection extending radially from the first member, which projection engages a curved slot in the second member.

9. A device as claimed in any preceding claim, wherein the mechanical coupling means is such that, while the second member is being displaced from a position in which the first and second cutting edges are spaced apart, the movement of the second member is initially mainly translational with relatively little rotational movement, but as the first and second cutting edges approach one another the movement of the second member becomes mainly or wholly rotational with relatively little or no translational movement.

10. A device as claimed in any preceding claim, wherein the first and second cutting edges are straight and parallel to the axes of the first and second members.

11. A device as claimed in any one of claims 1 to 9, wherein one or both of the first and second cutting edges islare concave.

12. A device as claimed in any one of claims 1 to 9, wherein both of the first and second cutting edges are straight and are such that, when one end of the first cutting edge is adjacent a corresponding end of the second cutting edge, an acute angle is included between the two cutting edges.

13. A device as claimed in any one of claims 2 to 7, or in any one of claims 8 to 12 when appendant to claim 2, wherein the first and second cutting edges are helicoidal.

14. A device substantially as hereinbefore described with reference to, and as shown in Figure 1,4 or 5; optionally in conjunction with Figure 2,6 or 7; and optionally in conjunction with Figure 3 of the accompanying drawings.