WO1993001754A1 - Surgical instrument actuator - Google Patents

Abstract

Designed for use in (but not limited to) laparoscopic surgery, this surgical instrument actuator (10) is a user-friendly handle (16) that contains operating means (20) which convert rotary input motion from a thumb operated input lever (20) to linear motion which is transmitted by means of an actuator rod (14) to the distal end (18) of the instrument (10) where the motion is used to operate various types of instrument tip assemblies (18) such as jaws, cutters, hooks, scissors, etc. The handle (16) is designed for right or left hand operation with minimum fatigue, and other features included are free rotation of the instrument tip(s) (18) about the axis of the main instrument shaft (12) a transitional lock system (58), accommodations for electric cautery (30), and a flushing system (108) for removing body fluids that leak into the main shaft tube (12) during surgery.

Description

SURGICAL INSTRUMENT ACTUATOR

BACKGROUND OF THE INVENTION

A. Field of the Invention

The present invention relates to the field of laparoscopic surgery which is a method of viewing and performing surgical procedures through very small incisions. Tubes (generally called trocars) on the order of 5 to 10mm (millimeters) diameter are inserted into the patient's body. A viewing instrument, called a laparoscope, is inserted into one trocar (10mm dia., for example), and various surgical instruments (for example, scissors and forceps) are passed in and out of one or more other trocars (5mm dia., for example) as the procedure is executed. Tiny television cameras can be attached to the laparoscope to transmit the operation to a television screen for viewing by the surgical team.

The principal advantage in this as compared to more invasive surgery is that the time required for the patient to recover is radically reduced because the body is subjected to much less trauma and injury.

The working ends of instruments used in laparoscopic surgery must be capable of reaching deep into the patient's body. The length of the main extension tube which joins the tips to the actuating handle must be on the order of 32 centimeters. This length, combined with the diameter limitation of the trocar (generally 5mm dia.), requires that the operating motion for the instrument tip which is manually input by the surgeon be transmitted to the instrument tip through the main shaft extension tube generally by means of a drive rod of even smaller diameter (on the order of 1.5mm dia.). The motion must be transmitted lineraly so the rod is put under tension when the surgeon applies force to cut, clamp or squeeze tissue at the tip of the instrument. Forces transmitted through means other than tension are usually inadquate because the small rod twists or buckles.

B. Problems in the Art.

Present day laparoscopic actuating instruments are made by rigidly joining a first arm to the mainn shaft of the instrument, and a second arm to the first arm at a fulcrum point close to the main shaft so that the second arm is free to rotate in a plane common to the longitudinal axis of the main shaft. In their normal position, these arms are offset about 30 degrees from a line perpendicular to the main shaft. The surgeon holds the instrument by gripping the arms through finger loops as is done in gripping a pair of scissors.

The second arm is attached to the rod that transmits motion to the tip. Thus, when the surgeon forces the moving arm towards the stationary arm, the rod is put under tension, and motion is transmitted which, in the case of a forceps, closes the tips of the instrument. When the surgeon forces the arms apart, the motion reverses, and the tips open.

The above described instruments work, but they are awkward and fatiguing in use. The surgeon is frequently forced to assume awkward arm and hand positions to place and orient the instrument tip.

The mechanical resolution of these instruments is very negative. A small amount of motion at the surgeon's hand produces a lot of motion at the tip. This is exactly the opposite of ideal, and the surgeon's control is less than it should be.

There is no effective way of cleaning these instruments. Body fluids leak inside the main shaft, and there is no way to flush out these fluids. This problem has created a new industry of throwaway laparoscopic instruments which is an abomination creating excessive costs and contamination throughout most of the civilized world.

SUMMARY AND OBJECTS OF THE PRESENT INVENTION

The present invention includes an actuator handle having a manual actuator which can be easily and conveniently gripped and operated by either the surgeon's left or right hand. An integral linear motion device transmits the action of the manual lever to a linear drive rod contained within a main shaft extension tube. A variety of surgical instrument tips can be attached to the distal end of the main shaft extension tube and be driven by the drive rod.

Additional features or options of the invention can include a tip rotary orientation feature which allows the tip to be rotated to any orientation without rotating the operating handle. Accommodations for electric cautery are also included with this rotary orientation feature. A transitional lock system can be utilized to lock the drive rod in any position along its stroke. A flushing system can be incorporated to clean the instrument.

The principal objects of the present invention are to overcome the above described negatives, and to create a reusable instrument that is safe, reliable, convenient and comfortable to use in both right and left hand surgery, is easily serviceable, and is cost effective.

These and other objects, features and advantages of the present invention will become more apparent with reference to the accompanying specification and claims. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a preferred embodiment of the invention including an example of a working tip that could be used with the invention.

Fig. 2 is an enlarged sectional view taken along line 2-2 of Fig. 1, showing the actuator according to the invention in a state where the manual input lever is in the up position (not depressed) .

Fig. 3 is essentially the same as Fig. 2 except showing the operating mechanism in a new position where the manual input lever is at the opposite end limit (fully depressed).

Fig. 4 is an enlarged isolated perspective view of the coupling through which motion is transmitted from the actuator to the rod that transmits the motion to the working end tip.

Fig. 5 is an exploded view of Fig. 4.

Fig. 6 is a partial sectional view taken along line 6-6 of Fig. 4.

Fig. 7 is a partial sectional view taken along line 7-7 of Fig. 2.

Fig. 8 is a sectional view taken along line 8-8 of Fig. 2.

Fig. 9 is an enlargement of the area within circle 9-9 in Fig. 3. Fig. 10 is an enlarged perspective view of elements taken generally along line 10-10 in Fig. 9.

Fig. 11 is a sectional view taken along line 11- 11 of Fig. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Overview

The preferred embodiment of the present invention involves principal parts which will be described in conjunction with the _"drawings, in order as followsr

A. The handle and integral linear motion device.

B. The tip rotary orientation feature including accommodations for electric cautery.

C. The transitional lock system.

D. The flushing system.

Figure 1 shows a complete assembly of the instrument 10 according to the present invention which contains as principle components handle 16, operating lever 20, transitional lock lever 26, main shaft 12, tip assembly 18, and monopolar cautery plug adaptor 30. These and other features are described below.

Basic operation of the instrument 10 is to hold handle 16 as a pistol, in either hand, and operate it by depressing lever 20 with the thumb of the hand. A. The Handle and Integral Linear Motion Device

The handle 16 is a plastic housing or shell which opens on one side so that the internal components can be assembled into the handle 16. The details of the opening and associated cover are not shown, and apply only to assembling the instrument.

Lever 20, Fig. 1, is duplicated in opposite hand configuration (not shown) on the opposite side of handle 16. Both levers are rigidly affixed to shaft 22 which is coupled to lever 36 (Fig. 2) by key 11 inside the handle. When lever 20 is moved (rotated), lever 36 moves in union. Shaft 38 (shown more completely in Fig. 7), is assembled into lever 36 and moves along arc 27. This end of lever 36 is bisected by a slot (15 in Fig. 7) to accommodate incorporation of slider 46. This will be explained in more detail later.

The diameter of both ends of shaft 38 is reduced to accommodate rollers 13. These rollers are assembled into the system so chat they are confined inside slots 40 in levers 42. (See Fig. 2). Levers 42 rotate around shaft 44 which is secured in handle 16. See _.ig. 7 which shows this assembly in section.

Movement of lever 36 forces movement of levers 42. Fig. 2 and Fig. 3 show that the rotation of lever 36 and corresponding rotation of levers 42 is limited by the len«gth of slots 40. In Fig. 2, rotation of lever 36 is stopped in the up position which is called the normal position; in Fig. 3, rotation of lever 36 is stopped in the down position. These limits establish the length of the stroke of the instrument.

In the normal position as shown in Fig. 2, levers 42 are in their most forward position (toward the distal end of the instrument), and in Fig. 3, levers 42 are at the opposite end of their stroke. Thus, levers 42 move in unison with the movement of manually-operated levers 20.

Movement of the upper ends of levers 42 is transmitted to drive rod 14 through the coupling assembly shown in Fig. 4. This assembly is integral with rod 14. Cylindrical portions 74 of trunnion 70 are cradled in slots 75 in the ends of levers 42 as shown in Figs. 2, 3, and 4. Thus, when levers 42 move, this movement is transmitted to trunnion 70 which transmits the motion to rod 14.

The coupling shown in Fig. 4 is designed to transmit linear motion along the axis of rod 14 and also to allow free rotary movement of rod 14. This is accomplished by blocking trunnion 70 between cylinders 76 and 78 so that the trunnion 70 can rotate but not move axially relative to rod 14. Cylinders 76 and 78 are keyed to rod 14 by pins 88 and 90 which engage slots or notches 84 and 86 in rod 14, and slots 80 and 82 in cylinders 76 and 78 (see Fig. 6). Pins 88 and 90 are confined in the assembly by Teflon shrink tubing 92 which is contracted by heating so that it cannot move from the installed position around cylinders 76 and 78.

Slider 46 (see especially Fig. 3 and Fig. 7) is pivotally mounted on shaft 38 at one end, and it straddles shaft 44 (and is separated from levers 42 by bushings 104) at the other end so that it is guided by shaft 44 as it moves up and down with the movement of lever 36. Slider 46 performs two functions; one is to work in cooperation with the transitional lock mechanism which will be explained later. The other function is to return the operating mechanism to the normal position by transmitting force from extension spring 54 to lever 36. This force produces clockwise motion in levers 36 and 20. The motion is stopped when the rollers 13 run into the upper ends of slots 40 in levers 42; which is the normal position (see Fig. 2).

In summary, the mechanism described above converts manual rotary input from either lever 20 to shaft 22 which rotates lever 36 to move shaft 38 and associated rollers 13 within the limits of slots 40 in levers 42. Motion of the rollers 13 transmits motion to levers 42 which rotate about shaft 44. Movement of the upper ends of levers 42 is coupled to rod 14 through the cylindrical portions 74 of trunnion 70 which moves rod 14 axially through the coupling shown in Figs. 4, 5 and 6. The mechanism returns to the normal position under the force of spring 54.

An important feature of this design is that the system is generic in that it can be adapted to accommodate many different strokes, and thus operate many different tip assembly configurations. The length and shape of the slots in levers 42 can be designed to produce an infinite variety of strokes. For example, the slot angle can be changed as the stroke progresses so that it changes motion resolution between the motion of lever 20 and the movement of rod 14. This will enable a stroke that produces a lot of motion at the first part of the stroke (relative to the motion of lever 20) with relative motion reducing to near zero at the end of the stroke where the gripping forces relative to input force would be greatly increased. Other slot lengths, shapes, angles, and/or orientations can be created to produce different actions. Another important feature of this design is that the mechanism is capable of producing motion in either direction from the start of the stroke, in the figures, movement of rod 14 is left to right between the normal position and the opposite position. The direction of the stroke could be reversed. This is accomplished by reversing the angle of the slot so that in the normal position, levers 42 are positioned at the extreme position away from the distal end of the instrument and as the stroke progresses, levers 42 move forward to push the rod toward the distal end of the instrument.

Another important feature is that the instrument is designed so that the surgeon is completely insulated from exposure to electric shock when using the instrument in cautery or coagulation. The handle is plastic, and lever 36 is also plastic so that no current can pass from the internal mechanism to lever 20. The main tube 12 is insulated with an outer shell 92 of Teflon tubing, and transitional lock lever 26 is insulated by installing a Teflon ball 27 at its outer end.

B. The Tip Rotary Orientation Feature Including Accommodations for Electric Cautery

Figs. 9 and 10 show washer 148 and pin 150 as they are assembled onto the proximal end of main tube 12. pin 150 is confined in a counterbore inside handle 16 so that it cannot slip out of tube 12. Pin 150, in contact with washer 148 which is at the bottom on the counterbore, prevents movement of tube 12 in bore 32 in handle 16 toward the distal end of the instrument 10.

Figs. 1, 3, and 8 show monopolar plug 30 and associated U-shaped tube claim 120 and washer 122. Monopolor plug 30 is threaded on the diameter that extends into clamp 120 which is threaded only in the bottom half (below the horizontal split line) . Tightening the monopolor plug 30 causes tube clamp 120 to squeeze tight onto tube 12, and thus prevent movement of the tube relative to handle 10 toward the proximal end of the handle.

Consequently, the tube is confined so that it cannot move axially relative to the handle, and it is free to rotate in the handle. The coupling shown in Fig. 4 allows free rotation of the rod 14, so the surgeon can orient the tip assembly 18 to any desired angle relative to the handle.

The monopolor plug 30 is used as a handle to rotate and orient the tips of the instrument in addition to being used as a connection for electric cautery. C. The Transitional Lock System

When activated, the transitional lock system is unidirectional in that it is capable of locking the movement of slider 46 so that spring 54 cannot return the slider 46 and associated levers 42, 36 and 20 to the normal position. When activated, the lock system does not prevent further downward movement of slider 46. In other words, in the lock mode, it holds slider 46 and all associated levers at their lowest point of depression until the lock is manually released.

The elements of the lock system are slider 46, shafts 44 and 60, cam 58, lever 26 and its associated spring 61 and integral ball 27, with detent 66. Cam 58, co-acting with slider 46, causes locking. Note that lever 26 is confined in a groove 59 in cam 58 and slides in that groove 59. This movement increases the center distance between shaft 60 and ball 27 so that the ball is able to override detent 66 when lever 26 is manually moved.

Fig. 2 shows the system in the off mode. Cam 58 is held in the position shown by lever 26 which is held in place by detent 66. In this position, slider 46 is free to slide up and down because cam 58 is unable to make contact with the slider. Fig. 3 shows the system in the lock mode, in this position, lever 26 holds cam 58 in contact with slider 46. The cam is designed so that contact with slider 46 is slightly below the line between the center of shafts 44 and 60. When pressure on lever 20 is released, frictional contact between slider 46 and cam 58 urges clockwise rotation of the cam. The cam is wedged and cannot rotate clockwise. It forces extension 50 of slider 46 against shaft 44 with a large force, thus pinching and gripping extension 50 so that it cannot move upward. Note that this configuration allows free downward movement of slider 46 at any transitional point in the stroke, to and including the end of the stroke where it is shown in Fig. 3.

D. The Flushing System

Figs. 9 and 11 show elements of the flushing system. Cleaning and rinsing solutions are pumped into the system through bore 118 which is tapered to receive a male luer lock fitting and thus able to connect a cleaning syringe to the handle and introduce fluids under pressure. Fluids move into cross bore 108, and into tube 12 through port 140 which is a slot in the side of tube 12. The fluids, which are prevented from flowing into the handle cavity by seal 144, flow to the distal end of the instrument. This action washes out the body fluids that leak into tube 12 during surgery. The final rinsing fluids are forced out of the distal end by compressed air, thus leaving the tube free of liquids ready for sterilization and more surgery.

Tube 12 is rotatable about its cylindrical axis as previously described. To allow passage of cleaning fluids, tube 12 is rotated to align port 140 with bore 108. This position is established by rotating the monopolor plug 30 so that it points down. It should be noted that bore 108 is permanently plugged by plug 142, and bore 118 is plugged during surgery to prevent free flow of body fluids when the monopolor plug is in the down position.

Claims

What is claimed is:

1. An acutator means for providing linear motion to a position extended from the actuator means comprising: elongated tube means having a distal end and a proximal end; elongated rod means slideably positionable within the tube means and having distal and proximal ends generally corresponding with the distal and proximal ends of the tube means; first attachment means associated with the distal ends of the tube and rod means adaptable to connect the rod means to a means utilizing linear motion of the rod means; second attachment means to connect the proximal ends of the tube and rod means to a handle means; the handle means including a gripping means, a manual control means, and translation means inside the handle means for translating movement of the control means into linear movement of the rod means.

2. The actuator means of claim 1 wherein the second attachment means includes means to allow free rotation of the tube means and rod means in relation to the handle means.

3. The actuator means of claim 2 wherein the second attachment means including a joint means which allows linear movement of the rod means by transmitting movement of the translation means to the rod means, while at the same time allowing free rotation of the rod means in any direction.

4. A surgical actuator for providing linear movement to a position extended from the actuator for such things as cutting, clamping, and gripping, comprising: a housing including an exterior portion adopted for gripping; an actuator lever mounted to the housing for providing manually generated force over a range of movement; transmission means in the housing for translating movement and force of the lever into straight line motion; coupling means for connecting an extension means, having a longitudinal axis and a distal end to the housing to allow translation of straight line motion of the transmission means to the distal end of the extension member.

5. The actuator of claim 4 wherein the transmission means comprises means for converting rotary motion of the actuator lever to linear movement of the extension member.

6. An actuator means for providing straight line movement to a surgical instrument working end extended at the end of a small diameter, elongated tube having a longitudinal axis, the working end and tube being insertable and withdrawable through a small incision in a patient's body wall to allow access of the instrument to a patient's body cavity, comprising: a handle means adapted for gripping in the palm of either hand of a surgeon; at least one lever means positioned on the handle means and adopted to be moved by a finger of the surgeon between and including first and second positions; linkage means for connecting the lever means with a driver means to transfer movement and force of the lever to the driver means; and the driver means having an end which is connectable to a driver rod slideably positioned within the tube and connectable to the working end, the driver means moving the driver rod linearly between and including extended and retracted positions along a line in response to movement of the lever, between and including the first and second positions.

7. The actuator means of claim 6 further comprising a flush means in fluid communication between the interior of the tube and the exterior of the housing to allow flushing of any fluid and debris from at least portions of the tube.

8. The actuator means of claim 6 further comprising an electrical cautery attachment means mounted on the tube and being connectable to an electrical power source to supply electrical power to at least a portion of the tube for cauterization procedures and insulating means for preventing electrical power from reaching the handle means and lever means.

9. The actuator means of claim 6 further comprising a transitional lock means for locking the driver rod in any position between the retracted and extended positions.

10. The actuator means of claim 9 wherein the transitional lock means includes a member pivotably slideable at one end over a shaft mounted in the handle means and connected at an opposite end to the linkage means, a cam member rotatably mounted to a second pivot shaft in the handle means spaced apart and to the side of the member, and a control arm for selectively moving the cam member between a locked position into abutment with the member to frictionally lock the member and an unlocked position out of abutment with the member.