AU672060B2 - Improvements in laparoscopic instruments - Google Patents

Description

6720 0 p00031I Reialo 2.2 AU$ TRALIA P?3tents Act, !990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Original TO BE COMPLETED BY THE APPLICANT NAME OP APPLICANT: AOTTJAL INVENTOR: ADDRESS FOR SERVICE: INVENTION TITLE: EUGFENIA EMILI A 27:LADY-- JOHN STLADY Peter Maxwell Associ,--,kes BlaaC~and House, Suite 10, 5 Ross Street, NORTH PARRAMATTA NSW 2151 IMPROVEMENTS IN LALPARhOSCOPCC INS TRUMENT S ?L 6717 8TH JANUARY, 1993 DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO: The following statement is a full description of this invention, 4ncluding the best method of performing it 1!nw to~ mp:- -2- The present invention relates to apparatus for performing minimal invasive surgery and like operations, and particularly to laparoscopic apparatus of the grasping or dissecting forceps type.

Conventional grasping forceps suffer from a number of disadvantages that can render t.eir utilization and maintenance difficult in the hands of relatively unsilled persons or where prompt action is required.

For instance, conventional grasping forceps cannot readily be dismantled so that they may be cleaned of blood or other tissue following surgical procedure.

Dismantling has previously been cumbersome and time consuming as it has included the ismantling of the scissors type handle of the forceps.

15 Secondly, the locking mechanisms of conventional grasping forceps commonly employ a ratchet arrangement to secure the jaws of the forceps in the desired grasping position. The ratchet is exposed and is located adjacent the scissors type handle at a site where the surgeon's fingers 20 are located, and this may undesirably l.i. to the surgeon's glove catching in the teeth of the ratchet during the surgical procedure.

Also, the ratchet cannot be fully insulated because of the need for ratchet teeth engagement and so, when a surgeon is cordarising an artery, an electric current may spread to other tissue of the patient or to the surgeon.

Thirdly, the shaft of most known grasping forceps cannot be rotated and held firmly or locked at the desired 1.

3 rotated position. Those that do have this feature require two handed operation by the surgeon for rotation and locking of the shaft and this can be disadvantageous where the surgeon is required to have one hand free of the grasping forceps during the surgical procedure.

It is an objcct of the present invention to overcome or substantially ameliorate the disadvantages of the prior art.

According to the invention there is provided a laparoscopic apparatus for use in surgical procedures, said apparatus comprising handle means, means for grasping tissue under surgical manipulation and means for controlling the operation of the said grasping means, said controlling means including trigger means whereby user finger pressure applied against the trigger means operates the grasping means, wherein the handle means a S. comprises a scissor handle and the controlling means further includes a cooperating means for allowing the trigger means to co-operate with the 15 scissor handle to operate the grasping means, and wherein the scissor handle consists of a reference arm which is rotationally fixed and a control arm which is rotationally movable relative to the reference arm, the grasping means being operable by separate finger pressure applied against the trigger means and against the control arm acting through the cooperating means, and wherein the co-operating means comprises a drum having a toothed portion, said drum being moveable with the control arm and connected rotatably to the reference arm, and a pawl on the trigger means, said pawl engaging the toothed portion of the drum when there is no finger pressure against the trigger means, whereby finger pressure applied against the trigger means will release the pawl from its engagement with the toothed portion, and finger pressure applied against the control arm will allow the control arm to rotationally move relative to the reference arm, thereby enabling operation of the grasping means.

Preferably, the trigger means includes spring means for resisting pressure applied against the trigger means, so that when pressure on the trigger means is relieved, the pawl will engage the toothed portion of the drum, thereby restricting any movement of the control arm relative to the reference arm and maintaining the grasping means at a desired open or closed position determined by the extent to which the control arm has been rotationally moved relative to the reference arm.

Preferably, the laparoscopic apparatus includes means for maintaining the grasping pressure of said grasping means, said pressure maintaining means including a shaft slidably movable between a first position where it causes the grasping means to be closed and a second position where it causes the grasping means to be fully opened, a portion of the said shaft being sprung into a corrugated profile.

i *aa a 9 a oo o a Preferably, the laparoscopic apparatus includes means for rotating the grasping means through manipulation by a finger from the same hand as is used for holding the handle means.

Preferably, the grasping means rotational means includes a rotating spindle, having at least one prong extending therefrom which is adapted for finger manipulation.

Preferably, the rotational means further includes a hollow rod connected to the rotating spindle so that rotation of the rotating spindle causes rotation of the rod, a shaft located within the rod and connected at one end to the

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grasping means and at the other end to means for controlling the grasping means, the said shaft being rotatable with the said rod so that rotation of the shaft and rod causes rotation of the grasping means.

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings, in which:- Fig. 1 is a side elevational view of a laparoscopic apparatus according to a preferred embodiment of the invention, Fig. 2 is an enlarged view of the controlling means for the grasping means for the apparatus of Fig. 1, and Fig. 3 is a side elevational view of the grasping means a 15 of the apparatus of Fig. 1.

The laparoscopic apparatus shown in Figs. 1 and 2 has a scissor type handle means consisting of a reference arm 11 and a control arm 12. The reference arm 11 is rotationally fixed and the control arm 12 is rotationally movable relative o* 20 to the reference arm 11 about pivot axis 18.

There is a trigger 13 which has a pawl 14 formed around the pivot axis 15 of the trigger 13. The pawl 14 is shown engaging the teeth 16 of a drum 17.

The drum 17 is connected rigidly to the control arm 12 so that it is movable therewith, and is connected rotatably to the reference arm 11 at an extended portion thereof (not shown) about the axis 18.

-7- The configuration of the teeth 16 is such that the teeth 16 can roll over the pawl 14 when force is applied downwardly on the control arm 12 but the teeth 16 will not be able to roll over the pawl 14 when force is applied upwardly on the control arm 12. Therefore, when the pawl 14 is engaged in the teeth 16 of the drum 17, the control arm 12 is restricted from rotating upwardly about axis 18 relative to the reference arm 11, but can rotate downwardly.

The drum 17 and pawl 14 constitute a means for allowing the trigger 13 to co-operate with the control arm 12 of the scissor handle means to control the operation of a grasping jaw 19, as will be described in more detail later.

The teeth of the drum 17 and the pawl 14 are normally covered and are spaced apart from the trigger 13 and handle 15 means a sufficient distance that the surgeon's glove will not catch in the teeth of the drum 17 during the surgical procedure. The covering of the drum 17 and pawl 14 also assists in insulating the apparatus.

When the pawl 14 is disengaged from the teeth 16 of the 20 drum 17, the control arm 12 can rotate in both directions about axis 18 relative to the reference arm 11.

Disengagement is achieved by finger pressure applied against the trigger 13. The trigger 13 has a spring plate formed integrally therewith, the free end of which is urged against a surface portion of the reference arm 11 so as to cause the trigger 13 to resist pressure applied thereagainst.

In this way, the absence of any finger pressure against the trigger 13 will bias the pawl 14 to engage the teeth 16 of -8the drum 17 so that the control arm 12 is rendered rotationally immovable in an upward direction about the axis 18.

The control arm 12 has a pocket 22 fored in its upper part, which pocket 22 receives a ball 23 Formed at one end of a shaft 24. There is an opening 25 to the pocket 22, but the ball 23 cannot move out of the pocket 22 whilst the control arm 12 is in the position as shown.

Adjacent to the ball 23 of the shaft 24, there is a near portion 26 of the shaft 24. The near portion 26 is integrally connected to an intermediate shaft portion 27 which is, in turn, connected to a far portion 28 of the shaft 24. Only the ball 23 and adjacent part of the near shaft portion 26 are exposed, with the remaining part of the near 15 shaft portion 26, the intermediate shaft portion 27 and the io0 far shaft portion 28 all being surrounded by a barrel 29, rnd 30 and clevis The barrel 29 consists of a serrated rotating collar .31, a main barrel portion 32 and a pronged rotating spindle 20 33. The main barrel portion 32 is rigidly fixed to an upper portion 34 of the reference arm 11. The spindle 33 has three prongs extending therefrom (only prongs 35 and 36 shown) at equal circumferential distances apart.

The far shaft portion 28 has a flattened part (not shown) which is connected by pivot pin 42 to an articulated linkage assembly 37 (also shown in Fig. 3) consisting of first and second linkage members 38 and 39 respectively and first and second jaw members 40 and 41 respectively. Pivot -9pin 42 passes through an overlapping hole formed in each of the first and second linkage members 38 and 39 and the flattened part of the far shaft portion 28 which is located therebetween.

First linkage member 38 is also connected by pivot pin 43 to an extended portion of first jaw member 40 and second linkage member 39 is also connected by pivot pin 44 to an extended portion of second jaw member 41. The first and second jaw members 40 and 41 are connected to each other by pivot pin 45 which snugly passes through holes (not shown) in the clevis 30a. The pivot pin 42 connecting the far shaft portion 28 with the first and second linkage members 38 and 39 is not held by the clevis 30a and so is able to slide therethrough when a force is applied in either direction on the shaft 24. The pivot pins 43 and 44 connecting the linkage members 38 and 39 to the jaw members 40 and 41 respectively are able to also move forward and backwards, but, as well, can move apart from and towards each other when a similar force is applied on the shaft 24. In order for the pins 43 and 44 to move apart and forward, there are upper and lower openings (not shown) in the clevis 30a through which the part of the linkage assembly 37 held by pins 43 and 44 @am/ can pass. As mentioned above, pivot pin 45 is held stationary with reference to the clevis 30a, although it freely allows the pivoting of the jaw members 40 and 41 when force acting through the linkage assembly 37 is applied in either direction on the shaft 24.

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The jaw members 40 and 41 will move apart from each other so as to expose the jaw teeth 46 when force is applied on the shaft 24 in a direction away from the control arm 12, hereinafter referred to as an outwardly direction. The jaw members 40 and 41 will move towards each other when force is applied on the shaft 24 in a direction towards the control arm 12, hereinafter referred to as an inwardly direction.

Frce is applied on the shaft 24 so that it can slide in an outwardly direction through the rod 30 by causing the control arm 12 to rotate upwardly about its pivot point 18, which, in turn, causes the shaft ball 23 which is contained in the pocket 22 formed in the upper part of the control arm 12 to move in a left to right direction (with reference to Figs. 1 and 2) towards the barrel 29, thereby opening the jaw 15 members 40 and 41.

Similarly, causing the control arm 12 to rotate downwardly will cause the shaft ball 23 to move in a right to left direction away from the barrel 29, which, in turn, 'causes the shaft 24 to slide in an inwardly direction through the rod 30, thereby closing the jaw members 40 and 41.

The ball 23 will not be able to move out of the pocket 22 during rotational movement of the control arm 12 and the extent of the movement of the ball 23, and therefore the shaft 24, is determined primarily L the extent to which the control arm 12 can rotate relative to the reference arm 11 and the distance between the sliding pivot pin 42 and stationary pivot pin 45 of the linkage assembly 37.

I -11- Therefore, the engagement of the toothed drum 17 of control arm 12 with the pawl 14 of sprung trigger 13 will not allow the shaft 24 to slide in an inwardly direction to open the jaw members 40 and 41 and this ensures that the jaw members 40 and 41 will remain tightly grasping the tissue under manipulation. Release of the jaw members 40 and 41 from the grasped tissue will only occur when there is disengagemenc of the drum 17 from the pawl 14 caused by finger pressure applied against the trigger 13. Then disengaged, rotational movement of the control arm 12 can cause the shaft 24 to slide freely either inwardly or outwardly until a desired open or closed jaw position is reached.

The intermediate shaft portion 27 is formed in a corrugated profile of narrower dimension than either the ne shaft portion 26 or far shaft portion 28. The corrugated profile serves as a force absorbing spring between the near and far shaft portions 26 and 28 and provides a means of reliably maintaining the grasping pressure of the jaw members 40 and 41. The corrugated profile will distort slightly across its longitudinal axis when grasping pressure is applied and cause the ends of the shaft 24 to force against their respective receiving members, thereby maintaining the shaft in a tensioned state. This ha the added advantage that the delicate linkage assembly 37 is protected against excessive and abrupt forces because some of the force is absorbed by deformation of the corrugated intermediate shaft portion 27.

-12- The serrated rotating collar 31 a _ronged rotating spindle 33 of the barrel 29 are adapted to rotate simultaneously with the rod 30, shaft 24 and 2inkage asseblhy 37, the rotational movement being referenced against the stationary main barrel portion 32.

Although not shown, the collar 31 is internally threaded and screwably engages a threaded expanded portion of the shaft 24. The threaded expanded shaft portion can slide through the main barrel portion 32 to a desired extent and has a rubber 0-ring fitted therearound and adjacent to the main barrel portion 32 so that the collar 31 can be screwed controllably against the main barrel portion 32. If the collar 31 is screwed tightly against portion 32, then collar 32 will be unable to rotate because of its tight abutment 15 against the rotationally immovable main barrel portion 32.

This in turn, prohibits the threaded expanded portion, upon which the collar 31 is screwed, from rotating, which, because the expanded portion is movable with the shaft 24, renders the shaft 24, spindle 33, rod 30, clevis 30a and linkage assembly 37 also rotationally immovable. Therefore, any 0 manipulation of the spindle 33 by a single finger will be unable to cause rotation of the linkage assembly.

*In practice, however, the collar 31 is screwed only so far as to squeeze the O-ring firmly against the main barrel portion 32, but not so tightly against the portion 32 that spindle rotation through manipulation by a single finger of the hand of the surgeon holding the apparatus is made impossible. The 0-ring provides an appropriate level of -13resistance to simultaneous rotation of the shaft 24, spindle 33, collar 31, rod 30 and linkage assembly 37.

The collar 31 can also be unscrewed from the threaded expanded portion of shaft 24.

In order to dismantle the apparatus for cleaning, repairing or replacing the components thereof, the trigger 13 is held in a pressed state and the barrel portion 32 or the spindle 33 are held stationary whilst the clevis 30a is unscrewed from the rod 30. The control arm 12 should not be gripped during this operation. Because the clevis 30a is connected to the shaft 24 through pivot pin 45, unscrewing the clevis 30a aay from the rod 30 also moves the shaft 24 outwardly from the rod 30. The engagement of the ball 23 in the pocket 22 allows the shaft 24 to rotate as it is moved 15 out of the rod 30 and causes the control arm 12 to gradually pivot away from reference arm 11 during this operation. The control arm 12 will pivot sufficiently to allow the ball 23 to slide out of the pocket 22 by pulling the shaft 24 '..outwardly through the rod 30. The shaft 24, clevis 30a and linkage assembly 37 can then be cleaned along with other components.

Therefore, with this arrangement, the control arm 12 need not be unscrewed or otherwise removed from the reference arm 11 for the ball 23 of shaft 24 to be removed from the pocket 22 and for the components of the apparatus to be cleaned.

The apparatus is preferably made of high grade stainless steel.

-14- In use, the surgeon holds the apparatus with thumb and central index finger passed through the finger holes of the control arm 12 and reference arm 11 respectively, leaving his or her forefinger free to operate the trigger 13 and the pronged rotating spindle 33. After locating the tissue to be grasped, the surgeon presses the trigger 13 and ra:ises the control arm 12 to a height corresponding to an appropriate jaw opening position, then grasps the located tissue by releasing the trigger 13 and lowering the control arm 12 until the desired grasping pressure is achieved. The surgeon can then release his or her grip of the arms 11 and 12 and the tissue will remain grasped at the desired pressure.

The surgeon can also rotate the jaw members 40 and 41 o to a desired orientation by forefinger manipulation of any of 15 the prongs of the rotating spindle 33.

Various modifications may be made in details of design and construction without departing from the scope or ambit of the invention.

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Claims (7)

1. A laparoscopic apparatus for use in surgical procedures, said apparatus comprising handle means, means for grasping tissue under surgical manipulation and means for controlling the operation of the said grasping means, said controlling means including trigger means whereby user finger pressure applied against the trigger means operates the grasping means, wherein the handle means comprises a scissor handle and the controlling means further includes a co-operating means for allowing the trigger means to co-operate with the scissor handle to operate the grasping means, and wherein the scissor handle consists of a reference arm which is rotationally fixed and a control arm which is rotationally movable relative to the reference arm, the grasping means being operable by separate finger pressure applied against the trigger means and against the control arm OV. acting through the co-operating means, and wherein the co-operating means comprises a drum having a toothed portion, said drum being moveable with the control arm and connected rotatably to the reference c arm, and a pawl on the trigger means, said pawl engaging the toothed portion of the drum when there is no finger pressure against the trigger means, whereby finger pressure applied against the trigger means will release the pawl from its engagement with the toothed portion, and finger pressure applied against the control arm will allow the control arm to rotationally move relative to the reference arm, thereby enabling operation of the grasping means.

2. The laparoscopic apparatus of claim 1 wherein the trigger means includes spring means for resisting pressure applied against the trigger means, so that when pressure on the trigger means is relieved, the pawl will engage the toothed portion of the drum, thereby restricting any movement of the control arm relative to the reference arm and maintaining r Lt~ 16 the grasping means at a desired open or closed position determined by the extent to which the control arm has been rotationally moved relative to the reference arm.

3. The laparoscopic apparatus of claim 1 and including means for maintaining the grasping pressure of said grasping means, said pressure maintaining means including a shaft slidably movable between a first pcosition where it causes the grasping means to be closed and a second o position where it causes the grasping means to be fully opened, a portion of the said shaft being sprung into a corrugated profile. S

4. The laparoscopic apparatus of claim 1 and including means for rotating the grasping means through manipulation by a finger from the same hand as is used for holding the handle means.

The laparoscopic apparatus of claim 4 wherein the grasping means "•."rotational means includes a rotating spindle, having at least one prong oooo• extending therefrom which is adapted for finger manipulation.

6. The laparoscopic apparatus of claim 5 wherein the rotational means further includes a hollow rod connected to the rotating spindle s-o that rotation of the rotating spindle causes rotation of the rod, a shaft located within the rod and connected at one end to the grasping means and at the other end to means for controlling the grasping means, the said shaft being rotatable with the said rod so that rotation of the shaft and rod causes rotation of the grasping means. ~3~i c' 8\ .4 ;IT< cl

7. A laparoscopic apparatus substantially as hereinbefore described with reference to the accompanying drawings. Dated this 17 day of July 1996 EUGENIA EMILIA SILADY Patent Attorneys for the Applicant PETER MAXWELL ASSOCIATES *S S S S S S 4j' <re-r I V ABSTRACT A laparoscopic apparatus for use in surgical procedures has a scissor type handle consisting of two arms (11, 12). One arm (11) is rotationally fixed and the other arm (12) is rotationally movable relative to the fixed arm (11). Operably connected to the handle (11, 12) is a means (19, 37) for grasping tissue under surgical manipulation, the grasping function being controlled by controlling means (22, 23, 27, 31, 33) and a trigger Finger pressure applied against the trigger (13) in co-operation with the handle (11, 12) operates the grasping means (19, 37). Co-operation between the trigger (13) and handle (11, 12) so as to operate the grasping means (19, 37) is achieved by a drum (16, 17) and pawl (14) arrangement. oo.. ft* ft 9 9