WO2006040562A1

WO2006040562A1 - Laparoscopic sewing device

Info

Publication number: WO2006040562A1
Application number: PCT/GB2005/003943
Authority: WO
Inventors: John Dalton Griffith
Original assignee: John Dalton Griffith
Priority date: 2004-10-13
Filing date: 2005-10-13
Publication date: 2006-04-20
Also published as: GB0422714D0

Abstract

A laparoscopic sewing device arranged to produce chain stitches, the device including a rigid elongate support body, a sewing head mounted to longitudinally project from one end of the support body and a sewing head operating mechanism located at the opposite longitudinal end of the support body, the sewing head having a needle arm carrying a sewing needle adapted to be threaded with suturing yarn, an anvil having an aperture through which the sewing needle may pass and through which, in use, said suturing yarn passes and a looper, the needle arm being pivotally movable relative to the anvil between a fully raised position whereat said needle is spaced above the anvil and a fully lowered position whereat said needle has penetrated through the aperture in the anvil, the needle arm also being movable axially relative to the support body between a fully retracted position and a fully advanced position, the anvil being axially movable relative to the support body in a direction toward said opposite longitudinal end of the support body when said needle arm is at its fully raised position so that, in use, the anvil is able to engage yarn passing through said aperture for axially advancing the support body during sewing and/or for tightening of sewn stitches.

Description

LAPAROSCOPIC SEWING DEVICE

The present invention relates, in particular, to a laparoscopic sewing device.

According to one aspect of the invention there is provided a laparoscopic sewing device arranged to produce chain stitches, the device including a rigid elongate support body, a sewing head mounted to longitudinally project from one end of the support body and a sewing head operating mechanism located at the opposite longitudinal end of the support body, the sewing head having a needle arm carrying a sewing needle adapted to be threaded with suturing yarn, an anvil having an aperture through which the sewing needle may pass and through which, in use, said suturing yarn passes and a looper, the needle arm being pivotally movable relative to the anvil between a fully raised position whereat said needle is spaced above the anvil and a fully lowered position whereat said needle has penetrated through the aperture in the anvil, the needle arm also being movable axially relative to the support body between a fully retracted position and a fully advanced position, the anvil being axially movable relative to the support body in a direction toward said opposite longitudinal end of the support body when said needle arm is at its fully raised position so that, in use, the anvil is able to engage yarn passing through said aperture for axially advancing the support body during sewing and/or for tightening of sewn stitches.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which:-

Figure 1 is a side view of a sewing device according to a preferred embodiment of the invention;

Figure 2 is a part side view of a sewing head according to an embodiment of the present invention;

Figure 3 is a plan view, from below, of the sewing head as shown in Figure 2; Figures 4 and 5 are each a similar view to Figure 2 showing the sewing head in a different mode for creating a stitch;

Figure 6 is a plan view, from beneath, of the sewing head as shown in Figure 5; Figure 7 is a part side view similar to Figure 5 illustrating drawing of yarn under low tension for forming the next loop;

Figure 8 is a part side view similar to Figure 5 illustrating drawing of yarn under high tension for forming the next loop; Figure 9 is a part side view of the sewing head of Figure 2 illustrating severing of yarn at completion of a series of sewn stitches;

Figure 10 is a part perspective view of the sewing head shown in Figure 1;

Figure 11 is an axial section through the sewing head of Figure 1 illustrated with the needle arm of the sewing head raised; Figure 12 is a similar view to Figure 11 with the needle yarn shown in a lowered position;

Figure 13 is an axial section along line XIII-XIII in Figure 11;

Figure 14 is an end view of the sewing head as shown in Figure 2;

Figure 15 is a part side view of the operating mechanism as shown in Figure 1 but shown in a different mode of operation;

Figure 16 is a part perspective view of the operating mechanism as shown in Figure 1.

Referring initially to Figure 1, there is shown a laparoscopic sewing device 10 according to a preferred embodiment of the invention.

The device includes an elongate support body 30 which is preferably in the form of a tube. The support body 30 is preferably rigid and is formed from a suitable rigid material such as a metal or rigid plastics.

Projecting from one longitudinal end of the support body 30 is a sewing head 80 and an operating mechanism 81 is located at the opposite longitudinal end of the support body 30.

As more clearly seen with reference to Figures 10 to 12, the sewing head 80 includes a looper L, an anvil 4, a needle arm 20 and a sewing needle 1. Preferably the needle arm 20 is pivotally attached to a carrier body 23 via a pivot pin 22. The carrier body 23 is slidably received within the tube defining body 30 for axial movement relative thereto.

The needle arm 20 is preferably provided with cam means for causing movement of the arm 20 about pivot pin 22 on axial displacement of the carrier body 23. Preferably the cam means comprises a cranked slot 31 formed in the needle arm 20 and a guide pin 21 passing through the slot 31, the pin 21 being secured to body 30. The cranked slot 31 includes a first slot portion 31a which extends generally parallel to the longitudinal axis of the body 30 and a second slot portion 31b which is inclined to the longitudinal axis of body 30. Accordingly, the sides of the slot 31 define a cam surface and the pin 21 defines a cam follower such that an axial displacement of the carrier body 23 to the right (in Figures 10 to 12) causes the pin 21 to enter the second slot portion 31b and so cause the arm 21 to rise away from anvil 4 to a fully raised position (as shown in Figure 11) whereat the pin 21 is located at the terminal end of slot portion 3 Ib.

Movement of the carrier body 23 in the left direction (from the position shown in Figure 11) causes the arm 20 to be lowered toward anvil 4 until it reaches a fully lowered position as shown in Figure 12; this position preferably corresponds with the pin 21 residing at the juncture between the first and second slot portions 31a, 31b respectively.

Continued movement of the carrier body 23 in the left direction from the position shown in Figure 12 causes the pin 21 to ride along the first slot portion 31a towards its terminal end and in so doing maintain the arm 20 at its fully lowered position. During this movement of carrier body 23, the needle arm 20 is advanced in an axial direction; this movement of arm 20 is hereinafter referred to as the 'clearing stroke' of arm 20.

Preferably the looper L is fixedly secured to the support body 30 so as to be immovable relative thereto. Preferably the looper L is formed by a pair of arms 2, 3 extending longitudinally of the support body 30; the arms 2, 3 being secured to body 30 via a support plate 27.

The arms 2₅ 3 are arranged side by side and each have a terminal head portion 90, 91 which includes a forwardly projecting terminal nose 92 defining an underlying shoulder 93 for retaining a loop of yarn. In other words the noses 92 act together to define a hook for retaining a stitch loop on the looper L. As seen in Figure 10 the axial extent of each nose 93 may be the same, or alternatively as seen in Figure 3, one nose 93 may project axially beyond the other.

Preferably as seen in Figures 2, 3, 10 and 12 when the pin 21 is located at the juncture between slot portions 31a, 31b the arm 20 is axially positioned such that the needle 1 has penetrated between the head portions 90, 91 at an axial position behind the terminal noses 92.

Preferably at least one of arms 2, 3 (more preferably both) are formed of a resilient material, such as a spring metal strip, so as to be capable of being laterally deflected on penetration of the needle 1 therebetween. This enables the head portions 90, 91 to be closely spaced whilst enabling a needle 1 of larger widthwise dimensions than the normal spacing between the head portions 90, 91 to pass inbetween the head portions 90, 91.

Preferably the depth of one or preferably both head portions 90, 91 is such that, together they act to shield the needle 1 from surrounding tissue as it penetrates downwardly beyond anvil 4. Preferably the depth of the or each head portion 90, 91 (i.e. its dimension in the direction of axial movement of the needle 1) is such that when the needle 1 resides at its fully inserted position (which corresponds to arm 20 being at its lowermost position), the needle tip only projects slightly or not at all beyond the lower edge of either head portion 90, 91.

As indicated by Figures 2 to 5, in order to form the next stitch S₁ within a series of chain stitches S, the needle 1 is lowered to its fully inserted position (Figures 2 and 3). At this position, the pin 22 is at the juncture between slot portions 31a, 31b. Also at this position, the needle 1 has penetrated between the head portions

90, 91 at a position behind bottom loop 10 held on the looper L.

The needle 1 is then advanced (in the longitudinal direction of body 30) by moving arm 20 along its clearing stroke. This causes the needle 1 to engage the side of the held loop 10 and clear it off the noses 93. Once released, the cleared loop 10' rides up the needle 1 to reside on the underside of the tissue 7 being sutured.

The needle 1 is then moved longitudinally in a rearwards direction to return the needle 1 to its longitudinal location corresponding to that shown in Figure 2. This motion of the needle 1 causes the U-shaped length of yarn LN guided by the needle 1 (see Figure 14) to be positioned on the outside of the head portions 90, 91 so that when needle 1 is then subsequently retracted, the length of yarn LN is caught by noses 93 to form the next held loop 10. Preferably as seen in Figure 14, the needle 1 is shaped to provide a recess 43 to facilitate penetration of noses 93 on arms 2 and 3. Preferably recess 43 is preferably defined by forming the needle 1 with a bent portion 41 so that the needle 1 produces a hole in the tissue 7 of minimum size.

Preferably the anvil 4 is arranged to move longitudinally of body 30. Preferably during the clearing stroke of arm 20, the anvil 4 moves longitudinally in the advance direction in synchronism with the needle arm 20 and similarly moves in synchronism with the needle arm 20 during its return stroke.

This movement of the anvil 4 is preferably achieved by biasing the anvil 4 in the left longitudinal direction and abutting the anvil 4 against the arm 20 at position 32 when the arm 20 is in its lowermost position such that longitudinal movement of the arm 20 causes movement of the anvil 4 with its bias in the left direction and against its bias in the right longitudinal direction. This can be conveniently achieved by connecting anvil 4 to a push rod 26 and providing a shoulder 32' on the push rod 26 which abuts the arm 20. By moving the anvil 4 in synchronism with the arm 20 during the stitch formation cycle, (i.e. the longitudinal movements of arm 20 whilst in its lowermost position), the opening 8 in anvil 4 through which the needle 1 passes need only be of a size and shape big enough to permit passage of the needle 1. This is advantageous as it enables an opening 8 of minimum size to be adopted and so assist in controlling penetration of the needle 1 through tissue 7 by providing maximum support to the tissue 7 surrounding the point of penetration.

Preferably, the anvil 4 is also movable rearwardly independently of the arm 20 when the arm 20 is in its raised position (see Figures 7 and 8). In this respect, as illustrated in Figures 7 and 8 the anvil 4 is arranged to be movable in a rearwards direction from the position shown in Figure 5.

This rearwards movement can be utilised to advance the sewing device to the next position for penetration of the needle 1 (Figure 7) and may also be used to tighten the last formed stitch Sx (Figure 8).

With regards to advancement of the sewing device to its next penetration position, as illustrated in Figure 7, on moving the anvil 4 in a rearwards direction, additional yarn is drawn from the needle 1 by virtue of the opening 8 engaging the yarn passing therethrough. As the relative longitudinal movement occurs between the anvil 4 and looper L, yarn is held by the previous stitch and so more yarn is pulled from the needle 1. In effect, as seen in Figure 7, anvil 4 creates a pulling action and looper L creates a pushing action for drawing fresh yarn. Accordingly, the looper L is able to advance in the direction of the series of chain stitches with the anvil 4 staying substantially in the same longitudinal position relative to the previously formed stitch.

With the arrangement shown in relation to Figure 7, it is assumed that tension applied to the yarn downstream of the needle 1 (i.e. on the supply side of the needle 1) is low so that yarn is drawn from the supply is preference to being drawn from the previously formed stitch. However, as illustrated in Figure 8, it is envisaged that increasing the tension in the yarn on the supply side of the needle 1 it is possible to draw yarn also from the previously formed stitch and so thereby tighten the stitch so as to more tightly grip the sutured tissue 7 and provide a fluid tight suture. The degree of tightness of the previously formed stitch can be controlled by suitably controlling the tension applied on the supply side of the needle 1 and also the extent of relative displacement between the anvil 4 and looper L.

Preferably movement of the anvil 4 and needle arm 20 are manually performed by operating mechanism 81. The operating mechanism 81 preferably includes a main body 65 which is fixedly secured to the support body 30.

The main body 65 has mounted thereon a first operating lever 53 which is pivotally connected to body 65 via a pivotal connection P₁. The lever 53 is also pivotally connected to a link block 51 which is in turn fixedly connected to one end of a push rod 25. The push rod 25 passes along the support body 30 and its opposite end is connected to the carrier body 23.

Lever 53 is biased, preferably by a resilient spring 55 to a retracted position such that carrier body 23 is biased to a retracted position whereat the pin 21 is located in contact with the terminal end of slot portion 31b. Accordingly, in the biased position of lever 53, the needle arm 20 is located in the position as illustrated in Figure 11.

A second operating lever 57 is mounted on the main body 65 via a pivotal connection P₂. The second operating lever 57 is linked via a pivotal connection P₃ to a link block 58. The link block 58 is connected to push rod 26. Biasing means, preferably in the form of a spring 56 is provided for biasing the push rod 26 in a direction to ensure that shoulder 32' is maintained in abutment with arm 20 and thereby ensures that the anvil 4 moves in synchronism with arm 20 during its stitch forming strokes. Pressing lever 57 towards body 65 causes the anvil 4 to be retracted rearwardly for performing advancement and/or stitch tightening operations. The sewing thread 63 is supplied on a bobbin 61, and is guided to the needle down grooves on one side of the body 30. It is tensioned by a friction device on the bobbin.

The end of the thread from the seam is led back through another bobbin 60, where it is wedged onto the bobbin. Preferably the bobbin 60 has a torsion spring device such as a clock spring inside it, so that the thread 62 is always held tight. Alternatively bobbin 60 may be held by a friction device, and turned manually to take up the slack as sewing proceeds.

Preferably a cutter blade 5 is located inbetween the arms 2, 3 and is movable from a retracted position ( Figure 11) longitudinally of the body 30 to an extended position (Figure 9) whereat it engages a held loop 10 and severs it as the cutter blade 5 advances. This produces a yarn tail T₁ connected to the last formed stitch ST and a yarn tail T₂ attached to the needle 1. It is therefore possible to retract the sewing device with yarn tail T₂ leaving tail T₁ attached to the last formed stitch S_T.

Claims

1. A laparoscopic sewing device arranged to produce chain stitches, the device including a rigid elongate support body, a sewing head mounted to longitudinally project from one end of the support body and a sewing head operating mechanism located at the opposite longitudinal end of the support body, the sewing head having a needle arm carrying a sewing needle adapted to be threaded with suturing yarn, an anvil having an aperture through which the sewing needle may pass and through which, in use, said suturing yarn passes and a looper, the needle arm being pivotally movable relative to the anvil between a fully raised position whereat said needle is spaced above the anvil and a fully lowered position whereat said needle has penetrated through the aperture in the anvil, the needle arm also being movable axially relative to the support body between a fully retracted position and a fully advanced position, the anvil being axially movable relative to the support body in a direction toward said opposite longitudinal end of the support body when said needle arm is at its fully raised position so that, in use, the anvil is able to engage yarn passing through said aperture for axially advancing the support body during sewing and/or for tightening of sewn stitches.

2. A sewing device according to Claim 1 wherein the looper includes a pair of arms extending longitudinally from the support body, the arms being spaced apart to receive said needle therebetween when said needle is at its fully lowered position.

3. A sewing device according to Claim 2 wherein at least one of said arms is formed from a resilient material so as to enable said arms to move apart on insertion of said needle therebetween.

4. A sewing device according to Claim 2 or 3 wherein at least one of said arms has a depth which is sufficient to shield said needle, in use, from surrounding tissue being sutured.

5. A sewing device according to an}' of Claims 1 to 4 wherein said anvil is axially movable in synchronism with said needle arm as it moves between its fully retracted and fully advanced positions.

6. A sewing device according to any preceding claim wherein said anvil is slidably mounted on said body and is biased into abutment with said needle arm so as to follow movement of said needle arm between its fully retracted and fully advanced positions.

7. A sewing device according to any preceding claim wherein cam means are provided which operably cause the needle arm to be moved from its fully raised to its fully lowered positions on movement of the needle arm from its fully retracted to its fully extended positions respectively, and vice versa.

8. A sewing device according to Claim 7 wherein the needle arm includes a cranked slot, a guide pin which is mounted on the support body extending through the slot such that the slot and pin co-operate to define said cam means.

9. A sewing device according to any preceding claim wherein said sewing head operating mechanism is manually operable, the mechanism including a first lever pivotally mounted on the support body, the first lever being connected to the sewing arm such that deflection of said first lever causes the needle arm to be moved between its fully extended and fully retracted positions, and a second lever pivotally mounted on the support body, the second lever being connected to said anvil such that deflection of the second lever causes the anvil to move in said direction toward said opposite longitudinal end of the support body.

10. A sewing device according to Claim 9 wherein first and second yarn bobbins are mounted on the support body adjacent to said operating mechanism, a first of said bobbins having a supply of yarn which is fed along said support body to said needle and a second of said bobbins receiving yarn originating from the beginning of a sewn seam, the second bobbin being rotationally movable to maintain the yarn in a taut condition extending between the second bobbin and the sewn seam.