fig1 , 3 and 4 depict an electro - surgical unit ( esu ) pencil apparatus 21 with a telescopic assembly 24 . the tip of the electrode 12 is defined as the distal end of the esu pencil apparatus 21 and the opposite end , the exhaust port 15 , is defined as the proximal end . hereafter in the specification , this definition is the reference for the use of the terms &# 34 ; distal end &# 34 ; and &# 34 ; proximal end &# 34 ; with respect to each element of the esu pencil apparatus 21 . the handpiece 22 has a locking cap 1 coupled to the distal end 25 of the handpiece 22 and an exhaust connector 13 attached to the proximal end 26 of the handpiece 22 . the tubular inner surface of the handpiece 22 is lined with a cylindrical conducting element 3 . rf energy flows to the esu pencil apparatus 21 from an rf source ( not shown ) via cord 14 . note that those skilled in the art refer to such an rf source as an esu , and the working tool 21 is typically called an esu pencil . on the outside of the handpiece 22 is a hand switch 4 , which controls the supply of rf energy from the cord 14 to the conducting element 3 . note that it is well known in the art to supply rf energy of a first specification for cutting and rf energy of a different specification for coagulation . the switch 4 alternatively activates both type of rf energy . the telescopic assembly 24 is contained within the conducting element 3 . the outer diameter of the tubing 9 , which forms the body of the telescopic assembly 24 , is marginally smaller than the inner diameter of the conducting element 3 , permitting the telescopic assembly 24 to slide along the longitudinal axis of the conducting element 3 . a rod 5 is suspended inside the tubing 9 by means of two spacers 34 and 35 . the plurality of fins 7 on the spacer 34 are slanted relative to the general direction of the flow of smoke and other fluids through the tubing 9 , such that a vortex is created when the fluids flow past these fins 7 . the rod 5 , and the spacers 34 and 35 , are made of conducting material . the socket 8 is located at the distal end of the spacer 34 . the electrode 12 is removably coupled with the socket 8 . alternatively , the electrode 12 could be integral with the socket 8 . at the proximal end of the tubing 9 is the conductor cap 6 . the conductor cap 6 is a thin tubular strip of metal that circles the outside of the proximal end 33 of the tubing 9 , and allows fluid access to the inside of the tubing 9 from the proximal end 33 . the outer surface of the tubing 9 at the proximal end 33 is slightly depressed so that the outer surface of the conductor cap 6 is flush with the outer surface of the tubing 9 . the conductor cap 6 has electrical contact with the spacer 35 . the spacer 35 is located at the proximal end 33 on the inside of the tubing 9 . the conductor cap 6 has a plurality of tangs 23 that provide an electrical link between the conductor cap 6 and the conducting element 3 . at the distal end 32 of the tubing 9 is the nozzle 11 . the nozzle 11 is hollow and tapered on its interior and exterior surfaces as viewed from near its proximal end 36 to its distal end 17 . this tapering not only helps to increase the visibility of the tip of the electrode 12 and the site of the operation , but also increases the efficiency of the fluid removal from the operation site by creating an exhaust vortex near the operation site . formation of the vortex is explained in detail later . making the nozzle 11 from a transparent material further aids the visibility . a portion near the proximal end 36 of the nozzle 11 is cylindrical and the outer diameter of the nozzle 11 is nearly equal to the inner diameter of the tubing 9 so that a substantially air - tight connection is formed when the proximal end 36 of the nozzle 11 is inserted into the distal end 32 of the tubing 9 . a locking mechanism is also provided to secure the connection between the nozzle 11 and the tubing 9 . the pin 16 on the nozzle 11 is designed to fit into the l - shaped slot 37 at the distal end 32 of the tubing 9 . a secure connection is made by sliding the pin 16 into the slot 37 and twisting the nozzle 11 . an alternative embodiment of the telescopic assembly 24 would have the nozzle 11 as an integral part of the tubing 9 . the telescopic assembly 24 is held in position within the handpiece 22 by the locking cap 1 . the exterior of the locking cap 1 is conical at the distal end and substantially tubular at the proximal end . however , the inside of the locking cap 1 is hollow and cylindrical . the inner diameter of the locking cap 1 is only marginally greater than the outer diameter of the tubing 9 . the tubing 9 passes through the locking cap 1 . the locking cap 1 is designed to connect to the distal end 25 of the handpiece 22 , with the locking cap threads 27 engaging the handpiece threads 28 . the locking cone 30 on the inner surface of the handpiece 22 is conical with the diameter at the proximal end 31 of the locking cone 30 being less than that at the distal end of the locking cone . as the locking cap 1 is screwed into the distal end 25 of the handpiece 22 , the slotted flanges 29 at the proximal end of the locking cap 1 press into the decreasing diameter of the locking cone 30 . thus , the flanges 29 are pressed inward by the decreasing inner diameter of the locking cone 30 , securing the telescopic assembly 24 to the handpiece 22 . the distal end of the exhaust connector 13 fits into the proximal end 26 of the handpiece 22 . the sleeve 38 , at the distal end of the connector 13 , is of marginally lesser outer diameter than the inner diameter of the proximal end 26 of the handpiece 22 , so that a substantially air - tight connection between the sleeve 38 and the handpiece 22 is formed . note , threaded engagement or other means of connecting well known in the art are acceptable to connect the exhaust connector 13 to the handpiece 22 . alternatively , the exhaust connector 13 could be integral with the proximal end 26 of the handpiece 22 . at the proximal end of the connector 13 is the exhaust port 15 that is connected to suction tubing ( not shown ). fig5 a - c , and 7a - c depict an esu - argon beam coagulator pencil apparatus 121 with telescopic assembly 124 , in accordance with the present invention . the tip of the electrode 112 is defined as the distal end of the esu - argon beam coagulator pencil apparatus 121 and the opposite end , the exhaust port 164 , is defined as the proximal end . as previously explained , the ends of all other elements of the esu - argon beam coagulator pencil apparatus 121 are referenced with respect to this definition of the distal and proximal ends . the handpiece 122 has a locking cap 101 coupled to the distal end of the handpiece 122 . an exhaust connector 113 is coupled to the proximal end of the handpiece 122 . the handpiece . 20 122 is similar to the earlier mentioned handpiece 22 , except that the handpiece 122 has an additional hand switch 150 for regulating the supply of coagulating material to the inlet port 162 . while the invention has been particularly described with argon gas as the inert material supplied , other inert fluids too could be supplied as the inert material . the inside of the handpiece 122 is lined with a cylindrical conducting element 103 . on the outside of the handpiece 122 are two hand switches 104 and 150 . handswitch 104 regulates the supply of rf energy from an rf source ( not shown ) via a cord 114 to the conducting element 103 . hand switch 150 regulates the flow of argon to the inlet port 162 . the telescopic assembly 124 ( shown in greater detail in fig6 c ) is contained within the conducting element 103 . the telescopic assembly 124 is similar to the previously described telescopic assembly 24 . the outer diameter of the cylindrical tubing 109 , which forms the body of the telescopic assembly 124 , is marginally smaller than the diameter of the conducting element 103 , permitting the telescopic assembly 124 to slide along the longitudinal axis of the conducting element 103 . a thin hollow rod 105 is suspended inside the tubing 109 by means of two spacers 134 and 135 . the plurality of fins 107 on the spacer 134 are slanted relative to the longitudinal axis of the tubing such that a vortex is created when smoke and other fluids flow past the fins 107 . the socket 108 is located inside the distal end of the rod 105 . the spacers 136 and 137 suspend the socket 108 inside the rod 105 . the electrode 112 is removably coupled with this socket 108 . alternatively , the electrode 112 could be integral with this socket 108 . the rod 105 , and the spacers 135 , 136 , and 137 are made of conducting material . at the proximal end of the tubing 109 is the conductor cap 106 . it is a thin tubular strip of metal that circles the outside of the proximal end of the tubing 109 , and allows fluid access to the inside of the tubing 109 from the proximal end of the tubing 109 . the outer surface of the tubing 109 at the proximal end is slightly depressed so that the outer surface of the conductor cap 106 is flush with the outer surface of the tubing 109 . the conductor cap 106 has an electrical contact with the spacer 135 . the spacer 135 is located at the proximal end on the inside of the tubing 109 . the conductor cap 106 has a plurality of tangs 123 that provide an electrical link between the conductor cap 106 and the conducting element 103 . coupled to the distal end of the tubing 109 is the nozzle assembly 111 . the nozzle 151 forms the exterior of the nozzle assembly 111 . the distal section of the nozzle 151 is conical , whereas the proximal section of the nozzle 151 is cylindrical . at the distal end of the nozzle 151 is an aperture , and the diameter of the aperture increases towards the middle of the nozzle 151 . from about the middle of the nozzle 151 to its proximal end , the nozzle is cylindrical . the inner diameter of the proximal end of the nozzle 151 is marginally larger than the outer diameter of the tubing 109 such that there is a substantially air - tight connection between the two , and yet the nozzle 151 can slide freely over the tubing 109 . the tapering of the distal section of the nozzle 151 not only helps to increase the visibility of the tip of the electrode 112 and the site of the operation , but also increases the efficiency of the fluid removal from the operation site by creating an exhaust vortex near the operation site . formation of the vortex is explained in detail later . making the nozzle 151 from a transparent material further aids the visibility . a locking mechanism ( shown more clearly in fig7 d ) prevents the nozzle from accidentally slipping out from over the telescopic assembly 124 . the locking mechanism is comprised of a u - shaped channel 120 , and a locking tab 102 . the channel 120 is cut on the inner surface of the nozzle 151 . the locking tab 102 is a protrusion located near the distal end of the tubing 109 and runs in the channel 120 when the nozzle 151 is coupled to the tubing 109 . the channel 120 has two legs 161 and 165 , running circumferentially around the longitudinal axis of the nozzle 151 . a bridge 163 , running longitudinally , connects the two legs . the log 165 traverses a substantial distance along the inner circumference of the nozzle and has access from the proximal edge of the nozzle 151 . the termination of the leg 165 at the proximal end of the nozzle 151 forms a loop to prevent the locking tab from accidentally slipping out of the channel 120 . when the nozzle assembly 111 is inserted over the telescopic assembly 124 the locking tab 102 is maneuvered into the leg 165 . when the nozzle assembly 111 is to be slid to and fro relative to the telescopic assembly 124 , the locking tab 102 moves in the bridge 163 of the channel 120 . when the locking tab 102 is in leg 161 , the mouth 154 will cover the tip of the electrode 112 . to remove the nozzle assembly 111 , the locking tab 102 is maneuvered past the loop of the leg 165 . note , other forms of locking mechanisms known in the art are also acceptable for locking the nozzle assembly 111 over the telescopic assembly 124 . another component of the nozzle assembly 111 is a tubular argon conduit 152 located inside the nozzle 151 . the conduit 152 is substantially cylindrical . the diameter of the conduit 152 is marginally larger than that of the rod 105 such that a substantially air - tight , yet slidable , connection is formed when the distal end of the rod 105 is inserted into the proximal end of the conduit 152 . a plurality of spacing vanes 153 are attached to the outer surface of the conduit 152 so as to suspend the conduit 152 inside the nozzle 151 . further , these spacing vanes 153 are slanted relative to the axial flow of smoke and other fluids through the nozzle assembly 111 so as to create a vortex flow . the mouth 154 of the conduit 152 extends beyond the distal end of the nozzle 151 . the mouth 154 flares out to prevent the argon gas coming out of the conduit 152 from being immediately drawn into the smoke duct 155 . the locking cap 101 is similar to the previously discussed locking cap 1 . as the locking cap 101 is screwed into the distal end of the handpiece 122 , the cap 101 will circumscribe a portion of the telescopic assembly 124 and lock the telescopic assembly 124 into place . the distal end of the connector 113 is designed to fit into the proximal end of the handpiece 122 . a sleeve 138 , at the distal end of the connector 113 is of narrower outer diameter than the inner diameter of the proximal end of the handpiece 122 , such that the sleeve 138 forms a tight seal when inserted into the proximal end of the handpiece 122 . note , threaded engagement or other means of connecting well known in the art may be implemented to connect the exhaust connector 113 to the handpiece 122 . alternatively , the connector 113 could be integral with the handpiece 122 . at the proximal end of the connector 113 are two ports -- the exhaust port 164 and the inlet port 162 . the exhaust port 164 is connected to a suction source ( not shown ) via tubing ( not shown ), and the inlet port 162 is connected to an argon supply ( not shown ). inside the inlet port 162 is a long , narrow , tubular member 160 , whose distal end is inserted into the proximal end of the rod 105 . the outer diameter of the tubular member 160 is marginally less than the inner diameter of the rod 105 such that a substantially air - tight , yet slidable connection is made between the tubular member 160 and the rod 105 when the tubular member 160 is partially inserted into the rod 105 . the length of the tubular member 160 is sufficient as to ensure uninterrupted flow of argon gas even when the telescopic assembly 124 is fully extended from the handpiece 122 . fig6 a - c and 7a - c depict some of the elements of the esu pencil apparatus shown in fig5 . fig6 a depicts a side view of the electrode 112 . fig6 b depicts a cross - sectional view of the nozzle assembly 111 . fig6 c depicts a cross - sectional view of the telescopic assembly 124 . fig7 a depicts the cross - sectional view of the nozzle assembly 111 taken through the spacing vanes 153 . fig7 b is an cross - sectional view near the proximal end of the nozzle assembly 111 . fig7 c is an cross - sectional view from near the distal end of the telescopic assembly 124 . fig8 a - g show another embodiment of an esu pencil apparatus 402 and smoke evacuation assembly or shroud 410 according to the present invention . this embodiment adopts the smoke evacuation assembly ( hereinafter shroud ) 410 for use with electrodes 406 of various lengths . the handpiece holder 421 is shaped to hold the handpiece 405 of an esu pencil apparatus 402 . the tip of the electrode 406 passes through electrode opening 422 , the nozzle 412 , and the exhaust opening 424 . the electrode opening 422 is shaped to substantially conform to the distal end of the handpiece 405 . the electrode opening 422 not only helps to support the esu pencil apparatus 402 , but also forms a substantially airtight seal around the contacting surface portion of the handpiece 405 . handswitch 404 regulates the rf supply to the electrode 406 . the nozzle 412 is detachably coupled to the connecting neck 426 of the shroud 410 . alternatively , the nozzle 412 could be integral to the shroud 410 . the passageway 428 inside the nozzle 412 , while quite narrow at the exhaust opening 424 , widens sharply towards the connecting neck 426 . the chute 420 is located alongside the handpiece holder 405 , and forms a path between the exhaust port 416 and the passageway 428 . the exhaust port 416 connects the chute 420 to a suction source ( not shown ). the tapering of the passageway 428 not only helps to increase the visibility of the tip of the electrode 406 and the site of the operation , but also increases the efficiency of the fluid removal from the operation site by creating an exhaust vortex near the operation site . formation of the vortex is explained in detail later . making the nozzle 412 from a transparent material further aids the visibility . when an extended electrode 430 ( fig8 c ), needs to be used with the esu pencil apparatus 402 , the exhaust opening 424 will be too far from the blade tip 436 to establish an effective exhaust flow in proximity of the blade tip 436 . in such circumstances , the nozzle 412 is detached from the shroud 410 , and is replaced with elongated nozzle 425 ( fig8 b ). the extended electrode 430 has a spacer 432 with a plurality of fins 434 that help stabilize the extended electrode 430 within the elongated nozzle 425 . if slanted to the general direction of the fluid flow through the elongated nozzle 425 , the fins 434 could be used to increase the efficiency of the vortex created by the venturi effect of the elongated nozzle 425 . note that there are many different angles at which the fins 434 , or any other fins herein may be situated to assist vortex flow . the tip of the extended electrode 430 could be of different types -- for example , a blade electrode ( 436 -- fig8 c ), ball electrode ( 440 -- fig8 d ), or a needle electrode ( 450 -- fig8 e ). fig8 f and 8g depict the end views of two embodiments of the present invention . these end views are taken from near the tip of the electrode 406 . fig8 f is the end view of the apparatus shown in fig8 a . here , the side of the chute 420 adjacent to the handpiece holder 421 is shaped to conform substantially to the shape of the handpiece holder 421 . fig8 g is the end view of a apparatus according to the present invention in which the chute 423 is substantially cylindrical . whereas fig8 a - g show adaptation of the invention for use with a esu pencil apparatus 402 , fig9 a - b , and 10a - b show two more embodiments of the present invention for use with two types of esu - argon beam coagulator pencils 502 and 602 . fig9 a - b show the adaptation of the shroud 510 for use with an esu - argon beam coagulator pencil apparatus 502 . in esu - argon beam coagulator pencil apparatus 502 the argon beam ( for coagulation ) surrounds the electrode 506 . the electrode 506 is activated by handswitch 503 , and the argon beam by handswitch 504 . the bolt 501 allows the electrode 506 to be extended ( see fig9 b ) and reacted ( see fig9 a ). the exhaust port 516 connects the shroud 510 to a suction source ( not shown ) via a smoke evacuation channel ( not shown ). the nozzle 512 is tapered and preferably made of transparent material . this helps to increase the visibility of the operation site and of the tip of the electrode 506 . the smoke and other fluids from the operation site enter the nozzle through a narrow opening at the tip 524 and proceed into a wider passageway inside the nozzle 512 . the resultant venturi effect increases the efficiency of fluid removal from the operation site by creating an exhaust vortex near the operation site . formation of the vortex is explained in detail later . a novel feature of shroud 510 is the adjustable nozzle 512 . a portion of the nozzle 512 is designed to slide within a neck piece 513 and lock in two extreme positions -- one retracted ( see fig9 a ) and the other extended ( see fig9 b ). when the nozzle 512 is retracted , it exposes the argon conduit tip 532 . when the nozzle 512 is extended , the tip of the nozzle 524 covers the argon conduit tip 532 , and is designed to be near the blade tip 507 of the extended electrode 506 , thus ensuring an efficient smoke removal near the blade tip 507 . fig1 a - b illustrate the adaptation of the shroud 610 for use over an esu - argon beam coagulator pencil apparatus 602 in which the argon conduit 630 is set apart from electrode 606 . fig1 a shows just the shroud 610 , and 10b shows the shroud 610 fitted over the esu - argon beam coagulator pencil apparatus 602 . handswitch 604 controls the rf energy supply to the electrode 606 , and handswitch 603 controls the argon supply . the bolt 601 allows the electrode 606 to be extended and retracted . a suction source , for removing the smoke from the site of the operation , is applied to the shroud 610 through the exhaust port 616 . the electrode passes through the nozzle 612 . the tapered nozzle 612 once again produces a vortex around the tip of the electrode 606 . a conduit access 628 fits around the conduit 630 . fig1 a - d show the adaptation of the shroud 710 for use with a laser surgery pencil apparatus 702 . the laser surgery pencil apparatus 702 is depicted in fig1 b , and the shroud 710 is depicted in fig1 d . the handpiece 704 of the laser surgical pencil apparatus 702 is generally of conical shape , but the shape of the handpiece is not a constraint for adaptation of the present invention . near the handpiece tip 705 of the laser surgery pencil apparatus 702 is a cylindrical neck 706 . when the handpiece 704 is used without the shroud 710 , the clip 709 of focusing cap 707 ( see fig1 c ) fits over the neck 706 and tip 708 of the focusing cap 707 marks the minimum safe operating point of the laser surgical pencil apparatus 702 . when laser surgical pencil apparatus 702 is used with the shroud 710 , the focusing cap 707 is removed from the neck 706 and the neck 706 is inserted into the passage 728 inside the holder 726 ( see fig1 d ). the shroud 710 fits around the laser surgical pencil apparatus 702 with the clamp 721 securing the head 730 of the laser surgical pencil apparatus 702 . a groove 722 in the clamp 721 locks around the cleaning gas inlet 732 so as to provide more stability to the fitting of the shroud 710 around the laser surgical pencil apparatus 702 . the shroud tip 725 provides measurement of the minimum safe operation point for the laser surgical pencil apparatus 702 . the smoke inlet 724 is located near the shroud tip 725 . an alternate embodiment would be to have more than one shroud tip 725 , each with its own smoke inlet 724 . the smoke inlet 724 is narrow and opens into a relatively wider exhaust chute 720 , which steadily widens as it moves away from the smoke inlet 724 . at the other end of the passageway is the exhaust port 716 , which is connected to a suction apparatus ( not shown ). a venturi effect on the fluid passing through the smoke inlet 724 increases the efficiency of the fluid removal from the operation site by creating an exhaust vortex near the operation site . formation of the vortex is explained in detail later . making the shroud tip 725 from a transparent material further aids the visibility . referring to fig1 , 3 and 4 , the rf supply ( not shown ) to the esu pencil apparatus 21 is controlled by means of the hand switch 4 . the rf energy flows from cord 14 to the conducting element 3 . from the conducting element 3 , the rf energy reaches the conductor cap 6 through the tangs 23 . the tangs 23 press against the conducting element 3 . because the conducting element 3 extends over the range of motion for the tang 23 along the longitudinal axis of the telescopic assembly 24 , the electrical contact between the tangs 23 and the conducting element 3 is continuous . from the conductor cap 6 , the rf energy passes on to the spacer 35 , the rod 5 , spacer 34 , and the electrode 12 . the smoke and other debris created during the surgical procedure is removed through the exhaust connector 13 , located at the proximal end 26 of the handpiece 22 . the smoke is sucked out from the exhaust connector 13 by suction means ( not shown ) such as a vacuum pump , via suction tubing ( not shown ) that is connected to exhaust port 15 . the passageway for the smoke and other fluids from the site of the operation to the exhaust port 15 is as follows : the fluids enter the esu pencil apparatus 21 through the distal end 17 of the nozzle 11 . the fluids then flow past the spacer 34 , the rod 5 , the spacer 35 , the handpiece 22 , and enter the exhaust connector 13 . the locking cap 1 , which is coupled with the handpiece 22 , forms an airtight seal with the handpiece 22 , and the slotted flanges 29 fit tightly over the tubing 9 forming another airtight connection with the outer surface of the tubing 9 . these airtight connections prevent air flow through the annular space between the conducting element 3 and the outer surface of the tubing 9 . the tapered shape of the nozzle 11 not only increases the visibility of the area being operated upon but also increases the efficiency of the smoke removal from the operation site . since the distal end 17 of the nozzle 11 leads into a wider passageway inside the nozzle 11 , a venturi effect causes an acceleration of these fluids as they pass through the distal end 17 . the pressure drop in the passageway immediately beyond the distal end 17 is large enough to produce a spiraling or &# 34 ; vortex &# 34 ; fluid flow through the nozzle 11 . this vortex soon extends to surround the tip of the electrode 12 . the vortex increases the efficiency of the smoke removal . the vortex is enhanced by the spacer 34 since the plurality of fins 7 is angled to the general direction of the flow of the fluids . note , while providing structures ( such as fins 7 ) inside the passageway of the fluids can enhance the efficiency of the vortex , such structures are not a requirement for the creation of a vortex . when the surgeon desires to change the distance of the tip of the electrode 12 from the handpiece 22 , the locking cap 1 is loosened . this releases the grip of the locking cap 1 on the telescopic assembly 24 , and it may now be extended or retracted as desired . when the desired length is reached , the locking cap 1 is tightened again , and the telescopic assembly 24 is locked into position . since the distal end 17 is always near the tip of the electrode 12 irrespective of the position of the telescopic assembly 24 within the hand piece 22 , the efficiency of smoke removal is not effected by the sliding of the telescopic assembly 24 . depending on how much of the tip of the electrode 12 the surgeon desires to have exposed , a nozzle 11 of appropriate size and shape may be used . after the operation , the electrode 12 , the telescopic assembly 24 , the nozzle 11 , and locking cap 1 are disposed of , but the handpiece 22 and exhaust connector 13 may be reused . referring to fig5 a - c , and 7a - c , a major additional feature introduced in this embodiment is the argon beam , whose activation is controlled through the hand switch 150 . the argon beam is conveyed to the site of the surgical procedure through the inlet port 162 , the tubular member 160 , the rod 105 , conduit 152 and finally the mouth 154 . the unique shape of the mouth 154 of the conduit 152 shields the argon beam from the exhaust suction , as will be explained below . smoke and other fluids from the operation site are removed through the smoke duct 155 by coupling a suction source ( not shown ) to the exhaust port 164 . smoke and other fluids from the operation site are sucked into the smoke duct 155 through the annular space between the mouth 154 of the conduit 152 and the tip 117 of the nozzle 151 . as previously explained , since the distal end of the smoke duct 155 tapers , and since the entrance to the smoke duct 155 is narrow , the venturi effect produced creates a vortex around the site of the operation . the plurality of spacing vanes 153 near the tip 117 are angled to the direction of the flow of the smoke and thus aid in the creation of the vortex . in the absence of the mouth 154 , the suction from the smoke duct 155 would tend to draw the argon beam directly into the smoke duct 155 prior to reaching the operation site , because the inlet of the smoke duct 155 surrounds the conduit 152 ( i . e . argon beam outlet ). this is a problem that prior technology has been unable to solve . now , this problem has been solved by having the outlet of the argon beam passageway ( i . e . the mouth 154 of the conduit 152 ) extend a little beyond the inlet of the smoke duct 155 ( i . e . the tip 117 of the nozzle 151 ), and having the mouth 154 flare out . the mouth 154 deflects the exhaust vortex made by the smoke duct 155 , and forms an eye of relative calm in the middle of the vortex . since the tip of the electrode 112 is located in the middle of this calm , the argon beam proceeds unhindered to the site of the operation . as smoke is created as a result of the operation , it will be pushed outward by the argon beam , where it will be captured by the exhaust vortex . sliding the nozzle assembly 111 over the tubing 109 enables the surgeon to vary the length of the tip of the electrode 112 that the surgeon desires to expose . the range of movement for the nozzle assembly 111 is determined by the locking mechanism . the locking tab 102 of the locking mechanism moves along the bridge 163 of the channel 120 , and the loop on the leg 165 prevents the nozzle 151 from accidentally slipping out from over the tubing 109 . the working of the telescopic assembly 124 is similar to that explained earlier for the telescopic assembly 24 . the smoke is conveyed from the operation site through the smoke duct 155 , the tubing 109 , the handpiece 122 , the exhaust connector 113 , and through the exhaust port 164 . the esu - argon beam coagulator pencil apparatus 121 may be used in three possible modes -- as an esu pencil for cutting and coagulation ( without argon beam ), as an argon - beam enhanced esu pencil for cutting and coagulation , and as a pure argon beam coagulator . when the esu - argon beam coagulator pencil apparatus 121 is to be used for cutting and coagulation without the argon beam , the of hand switch 104 is alternatively placed in the cutting and coagulation positions , while the argon hand switch 150 remains in the off position . the nozzle assembly 111 is adjusted ( by moving the nozzle assembly 111 to and fro ) over the telescopic assembly 124 to expose the desired length of the electrode 112 . the nozzle assembly 111 is positioned over the telescopic assembly 124 so as to maximize the suction on the operation site without hampering visibility of the tip of the electrode 112 or of the operation site . the optimal position of the nozzle 111 is a matter of personal preference of the surgeon . when the esu - argon beam coagulator pencil apparatus 121 needs to be used as an argon - beam coagulation enhanced esu pencil for cutting and coagulation , then the rf hand switch 104 is alternatively placed in the cutting or coagulation position , and the argon hand switch 150 is switch on . the nozzle assembly 111 is adjusted to maximize the efficiency of the argon beam , the efficiency of the removal of the smoke and other fluids from the site of the operation , and the visibility of both the tip of the electrode and the site of the operation . the optimal position of the nozzle 111 , once again , is dictated by the personal preference of the surgeon . in the final mode , when the esu - argon beam coagulator pencil apparatus 121 needs to be used purely as an argon - beam coagulator , the rf hand switch 104 is switched to the coagulation position , and the argon hand switch 150 is switch on . because the electrode 112 is not required for this procedure , the nozzle assembly 111 is moved out to cover the tip of the electrode . to lock the nozzle assembly 111 in this position , the locking tab 102 is maneuvered into the leg 161 of channel 120 . now the mouth 154 of the conduit 152 becomes the distal tip of the whole esu - argon beam coagulator 121 . this allows the argon beam to be released very close to the site of the procedure , thereby maximizing the efficiency of the argon beam . suction is used to remove smoke and other fluids created during the coagulation . referring to fig8 a - g , the esu pencil apparatus 402 is mounted in the handpiece holder 421 of the shroud 410 . a suction source ( not shown ) is coupled to the shroud 410 through the exhaust port 416 . the smoke and other fluids from the operation site are sucked into the passageway 428 inside the nozzle 412 through the exhaust opening 424 . the chute 420 conveys smoke and other debris from the passageway 428 to a debris collector ( not shown ) via the exhaust port 416 and the smoke evacuation channel ( not shown ). since the narrow exhaust opening 424 leads into a wider passageway 428 inside the nozzle 412 , the nozzle 412 produces a venturi effect on the fluids flowing into the nozzle 412 , causing an acceleration of these fluids as they pass through the exhaust opening 424 . further , the pressure drop in the passageway 428 immediately beyond the exhaust opening 424 is large enough to produce a spiraling or &# 34 ; vortex &# 34 ; fluid flow through the nozzle 412 . this vortex soon extends to surround the tip of the electrode 406 . note , while providing structures ( such as vanes ) inside the passageway 428 can enhance the efficiency of the vortex , such structures are not a requirement for the creation of a vortex . since the passageway 428 widens sharply from the exhaust opening 424 towards the connecting neck 428 , the pressure lost in the passageway 428 is minimal . nozzle 412 is replaced with the elongated nozzle 425 when the extended electrode 430 is to be used with the esu pencil apparatus 402 . this permits efficient collection of the fluids from near the blade tip 436 . as explained previously , a vortex is created by the venturi effect at the entrance of the nozzle 425 . further , the slanted fins 434 augment the vortex created by the venturi effect . fig9 a - b , and 10a - b show two more embodiments of the present invention for use with two types of esu - argon beam coagulator pencils . fig9 a - b show the adoption of the shroud 510 for use with an esu pencil apparatus 502 which has an argon beam ( for coagulation ) surrounding the electrode 507 . a suction source ( not shown ) is coupled to the shroud 510 through the exhaust port 516 . since the smoke inlet 524 is narrow and opens into a relatively wider passageway inside the nozzle 512 , a venturi effect causes the fluids passing through the smoke inlet 524 to accelerate . as explained earlier , when the smoke and other fluids accelerate through the smoke inlet 524 , the rushing fluids spirals and form a vortex . this vortex increases the efficiency of the evacuation of the fluids generated at the site of the operation in fig9 a , when the electrode 506 is retracted , the esu pencil apparatus 502 is to be used purely as an argon beam coagulator . the rf hand switch 503 is set to the coagulation position and the argon hand switch 504 is turned on . the suction source ( not shown ) is also turned on to remove smoke and other fluids produced during the coagulation process . the nozzle 512 is retracted , so that the conduit tip 532 extends beyond the nozzle tip 524 thereby permitting uninterrupted passage of the argon beam from the argon conduit 530 to the operation site . now , if the electrode 506 is extended , and the rf switch 503 is alternatively placed in cutting and coagulation positions , the cutting and coagulation functions of the esu pencil apparatus is enhanced by the argon beam . in fig9 b , the esu pencil apparatus 502 is to be used as a normal esu pencil ( i . e . without an argon beam ). the electrode 506 and the nozzle 512 are extended . the rf hand switch 503 is alternatively placed in the cutting and coagulation positions , and the argon hand switch 504 is switch off . the operation of the apparatus in fig1 a - b is similar to that explained above for the apparatus in fig9 a - b . the shroud 610 has been adapted for use with an esu pencil apparatus 602 which has an argon beam ( for coagulation ) set apart from the electrode 606 . a suction source ( not shown ) is coupled to the shroud 610 through the exhaust port 616 . as explained earlier , the venturi effect accelerates the smoke and other fluids through the smoke inlet 624 and forms a vortex around the electrode 606 . this vortex increases the efficiency of the evacuation of the fluids generated at the site of the operation when the electrode 606 is retracted , the esu pencil apparatus 602 is to be used purely as a coagulator . when the esu pencil apparatus 602 is used for cutting , the electrode 606 is extended . the suction source ( not shown ) is switched on , and the argon supply switch 504 is turned off . when the esu pencil apparatus 602 is to be used simultaneously as both an esu pencil for cutting and an argon beam coagulator ( as an &# 34 ; argon beam coagulator enhanced esu cutting pencil &# 34 ;), the electrode 606 is extended . the rf hand switch 603 is set to cut , and the argon hand 604 is turned on . the nozzle 612 shield the argon beam from the suction . referring to fig1 a - d , the present invention has been adapted to work with a laser surgical pencil apparatus 702 . a suction source ( not shown ) is applied to the exhaust port 716 which sucks in smoke and other fluids into the smoke inlet 724 from site of the operation . since the smoke inlet 724 is narrow and opens into a relatively wider exhaust chute 720 , a venturi effect causes the fluids passing through the smoke inlet 724 to accelerate . as explained earlier , when the smoke and other fluids accelerate through the smoke inlet 724 , the rushing fluids spirals and form a vortex . this vortex increases the efficiency of the evacuation of the fluids generated at the site of the operation . while the invention has been particularly shown and described with reference to the preferred embodiments thereof , it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention . for example , any of the previous embodiments of the invention may be modified to include a means for regulating the suction applied to remove , the smoke and other fluids from the site of the operation . also , if desired , a telescopic member could be achieved by using a screw type arrangement , a rack and pinion arrangement , or a series of notches and corresponding protrusion , as suggested by the nozzle arrangement in fig7 d .
an electro - surgical unit pencil apparatus having a removable shroud adaptably fitted over an external surface of a surgical pencil is presented where the pencil apparatus includes a conduit located within the shroud having a tapered portion surrounding the surgical pencil and in communication with the distal end of the shroud . an external conduit may be coupled to the proximal opening of the shroud and smoke evacuation means may be coupled to the external conduit for exhausting smoke from the shroud . the conduit includes an open proximal end , an open distal end , and a generally semi - circular shaped hollow interior , a handpiece holder located near a top outer surface of the conduit , and a nozzle member attached near the distal end of the conduit .