SUPPLY SYSTEM FOR STERILE FLUIDS AND GASES

Abstract: A fluid supply system for gas and sterile liquids con­ sisting of a disposable sterile cartridge (3) that is connected to gas (13) and liquid (7) sources and a common exhaust (29). The cartridge (3) cooperates with a rotating bearing as­ sembly (125) which pumps the liquid through the system without ever contacting the liquid. The gas sources (13) are provided with means for supplying (37) the gas under pres­ sure to the cartridge. A suitable control (200) selects either the gas or liquid source and a pair of gauges (73, 91) moni­ tor the flow of the fluids.

Description: BACKGROUND OF THE INVENTION The invention relates, generally, to laser surgery and, more particularly, to a device for supplying pressurized fluid to a flexible fiber optic guide. Surgical lasers are typically comprised of a main chassis for generating the laser energy coupled through a flexible fiber optic guide to the surgical instrument. The flexible fiber optic guide consists of and optic fibre through which the laser energy travels and a flexible sleeve arranged coaxially over the optic fibre for the length thereof. The space between the optic fiber and the sleeve acts as an annular conduit for delivering fluid through the guide to the surgical instrument. The fluid is used to keep debris, generated during the operation procedure, away from the optic fibre and surgical instrument. The fluid also acts as a coolant and is especially beneficial in this regard during so call "contact surgery", where the surgical laser instrument actually contacts the tissue. The fluid, in these laser systems, flows in an open system from the source through the fiber optic guide to the surgical tip where it is discharged at the operation situs. Because the fluid is discharged at the operation situs, it is critical that the fluid, especially liquid, remains in a sterile condition throughout the supply operation. To insure the sterility of the fluid, the sterile fluid source and the fiber optical guide are made disposable and are replaced after each operation procedure. The known prior art systems achieve this result by connecting a standard I.V.-type bottle directly to the fiber optic guide. The bottle is elevated such that gravitational force propels the liquid through the system. While this rudimentary system maintains the sterility of the liquid, the use of gravity to propel the liquid makes it very difficult to select or regulate the flow rate of the liquid. Of course, variances in the flow rate of the fluid can have serious repercussions in the type of sensitive surgical operations in which these laser surgical instruments are used. Moreover, in order to sterilise the flow rate indicators of the prior art they must be dismantled. Thus, because these prior art devices must be sterilised before each use, their upkeep and maintenance is very expensive. An example of a known type of cassette for a surgical system is disclosed in US Patent No. 4493695 issued to Cook. Cook's apparatus is designed to simplify the "hook-up" of the various wires and plugs normally associated with a microsurgical suction system by isolating the various connections in a single disposable cassette. However, this apparatus does not provide a controllable pumping means for varying the flow rate of the fluid. Cook merely uses a "gate" 82 for restricting the liquid path. Moreover, Cook does not disclose a gas delivery system that is controllable in conjunction with a liquid delivery system. WO-A-86/6964 discloses a disposable cartridge for use with a system for supplying sterile liquid and aspiration to a surgical instrument. The cartridge has a liquid input, an input for aspiration and a common output. OBJECTS OF THE INVENTION It is a general object of the invention to provide an improved supply system for sterile fluids. It is another object of the invention to provide a supply system for sterile fluids in which a pumping apparatus is used to propel the fluid. It is a further object of preferred embodiments of the invention to provide a supply system for sterile fluids where it is possible to select from a plurality of fluid sources. It is still a further object of preferred embodiments of the invention to provide a supply system for sterile fluids where the flow rates of the fluids can be precisely regulated. It is yet another object of preferred embodiments of the invention to provide a supply system for sterile fluids where the components contacting the sterile fluid are disposable. According to one aspect of the invention there is provided a supply system for supplying gases and sterile liquids characterised by a disposable sterile cartridge having a gas input, a liquid input, and a common output; a gas supply external and separate from said cartridge connected to said gas input for delivering gas thereto; a liquid supply connected to said liquid input for delivering liquid thereto; means for pressurizing the gas of said gas supply; and means external to and separate from said cartridge and cooperating therewith to pump the sterile liquid of said liquid supply through the system whenever a supply of the sterile liquid is delivered to the liquid input while maintaining the sterility of the liquid therein. According to another aspect of the invention there is provided a disposable cartridge for a sterile gas and sterile liquid supply system, characterised by an upper section having a first, second and third conduits formed therein, wherein said first conduit includes a liquid input port at one end thereof and said second and third conduits terminate at their respective one ends in a common chamber, said chamber including an output port; a lower section integrally joined with said upper section including a hollow chamber; a gas input port formed in said hollow chamber for receiving pressurised sterile gas; and means cooperating with a pump for pumping sterile liquid through the cartridge in a first flexible conduit means connecting said first and third conduits; second flexible conduit means connecting said second conduit to said gas input port whereby gas and liquid entering the cartridge through the gas input port and liquid input port, respectively, are exhausted at said common output port. BRIEF DESCRIPTION OF THE DRAWINGS This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic diagram of the various components of the invention; Figure 2 shows a front view of the cartridge of Figure 2 with its front half removed to provide a supply system for sterile fluids in which a pumping apparatus is used to propel the fluids; Figure 3 shows an exploded view of the components of the invention; Figure 4 shows a front view of the cartridge receptacle with the cartridge inserted; and Figure 5 shows a view comparable to that of Figure 4, where the outer wall of the receptacle has been removed. DETAILED DESCRIPTION OF THE INVENTION The fluid supply system of the invention is shown schematically at 1 in Figure 1 and includes a disposable sterile cartridge 3 having a first input port 5 connected to a sterile liquid supply 7 by conduit 9. A second input port 11 formed on the cartridge 3 is connected to a gas supply 13 by a conduit 15. The gas supply 13 includes two alternate gas sources 17 and 19 that are connected to a solenoid actuated valve 23 by conduits 25 and 27, respectively. The valve 23 can be activated to connect either one of the two gas fluid sources to the conduit 15. The cartridge also includes a single output port 29 that is connected to the fiber optic guide 31. A surgical instrument 33 is located at the distal end of the guide 31. A first pumping mechanism 35 is associated with the cartridge 3 for pumping liquid from the liquid supply 7 to the fiber optic guide 31 and a second pumping mechansim 37 is associated with the first gas source 17 to pump gas from the gas supply 13 to the fiber optic guide, as will hereinafter be described. The cartridge 3, shown in Figs. 2 and 3, consists of an upper section 39 formed of transparent plastic material including conduit sections 41, 43 and 45. Conduit section 41 terminates at its one end in input port 5 that is connected through conduit 9 to a liquid source 10. The liquid source 10 could be, for example, a conventional I.V. bottle. Conduit sections 43 and 45 terminate at their one ends in a chamber 47 that, in turn, exhausts through output port 29 to the fiber optic guide 31. Integrally joined with upper section 39 is lower section 49 formed of an opaque molded plastic. Lower section 49 is molded in two halves that, when joined together, form a hollow chamber 48. Lower section 49 includes notched recesses 51 and 53 formed in opposite sidewalls 55 and 57, respectively, and an arcuate recess 59 having a semicircular bearing surface 143 formed in the bottom wall 61. Figure 2 shows the cartridge 3 with one half of the lower section 49 removed to expose its internal structure. A first end of a flexible conduit 63 is connected to port 65 formed at the end of conduit section 41 opposite input port 5. The flexible conduit section 63 extends from port 65 and is sealably connected to port 71 formed at a first end of conduit section 45. A portion of conduit section 63 extends externally of the cartridge 3 in the area of arcuate recess 59, the function of which will be hereinafter described. Conduit section 45 forms a portion of gauge 73 that includes a float 75 slideable within conduit section 45 to cooperate with graduated markings 77 formed in upper section 39 to thereby indicate the flow rate of the liquid entering the fiber optic guide 31. The cartridge 3 further includes the gas input port 11 that consists of a pliable rubber nipple 81 which is able to be connected to the gas fluid source 13, as will hereinafter be described. The nipple 81 is air tightly connected to a first flexible conduit section 83 that, in turn, is connected to a filter 85. Filter 85 is connected to a second flexible conduit section 87 that is sealably connected to port 89 formed at a first end of conduit section 43. Conduit section 43 forms a portion of gauge 91 that is identical in construction to gauge 73 including float 76 and graduated markings 78, and gives the flow rate of the gas entering the optic fibre guide 31. A suitable one way valve arrangement 80 is used to prevent the backflow of fluid from the chamber 47 into the conduit 43. The pumping mechanism 35 associated with cartridge 3 for propelling the liquid is shown generally at 93 in Figures 3 through 5. The pumping mechansim 35 includes a cartridge receptacle 97 that slideably receives the cartridge 3. The receptacle 97 includes a front wall 99, a back wall 101, and a pair of L-shaped side walls 105 and 106 arranged for form a cavity 107 into which the cartridge 3 can be inserted. A pair of arm members 113 and 115 are pivotably mounted on shafts 109 and 111, respectively, and are operatively joined together by a link 117 such that application of a force to the arm members pivots them in unison away from cavity 107 to the dashed line position of Fig. 5. A tension spring (not shown) returns the arm members 113 and 115 to the solid line position of Figure 5 when the force is removed. The arm members 113 and 115 include inwardly extending fingers 121 and 123, respectively, that extend into the area of cavity 107 to cooperate with the notched recesses 51 and 53, formed in the cartridge 3, to thereby lock the cartridge into receptacle 97. The receptacle 97 further includes a rotating bearing cam 125 that comprises a wheel 127 fixedly secured to shaft 129. The shaft 129 is journaled in bearing assemblies 130 and 132 located, opposite one another, in front and back walls 99 and 101 such that the rotation of shaft 129 results in the rotation of wheel 127. A plurality of cylindrical bearings 131 are rotatably supported at regular intervals about the periphery of wheel 127 with their axis of rotation 134 arranged parallel to the axis of rotation of shaft 129. The cartridge 3 is dimensioned such that the lower section 49 can be inserted into cavity 107 the corners 133 and 135 of the lower section 49 contact camming surfaces 137 and 139 formed on the unwardly extending fingers 121 and 123, respectively, to thereby rotate the arm members 113 and 115 to the open position shown in dashed line Figure 5. When the cartridge 3 has been fully inserted into the cavity 107 a tension spring (not shown) pivots the arm members 113 and 115 to their upright positions to thereby lock the cartridge 3 into receptable 97 by the engagement of fingers 121 and 123 with recesses 51 and 53, respectively. To remove the cartridge 3 from the receptable 97, a force is applied to the lever 119 to thereby pivot fingers 121 and 123 out of engagement with recesses 51 and 53. The cartridge 3 can then be easily withdrawn from cavity 107. As shown in Figure 5, when the cartridge 3 is in the locked position within cavity 107, the nipple 81 sealably engages port 141 located in the L-shaped side wall 105 of receptable 97. Port 141 is connected to the gas supply conduit 15 to thereby connect the cartridge 3 to the gas supply 13. Moreover, the arcuate recess 59 is dimensioned so as to be received over the rotating bearing cam assembly 125 such that the exposed length of flexible conduit 63 is trapped between the cylindrical bearings 131 and the semicircular bearing surface 143. A peristaltic motor 145, shown in Fig. 3, is fixedly secured to frame member 95 such that its output shaft 147 is received within the shaft 129. The output shaft 147 and shaft 129 are keyed together such that rotation of the output shaft 147 results in rotation of the bearing cam 125 in the direction of arrow A. The cylindrical bearings 131 deform the exposed length of conduit 63 against the arcuate bearing surface 143 as the bearing cam 125 rotates to thereby pump the liquid fluid from supply 7 to the fiber optic guide 31. It should be noted that when the bearing cam 125 is not rotating, it pinched the flexible conduit against the arcuate bearing surface such that back flow of fluid through the liquid supply is prohibited. As is evident from the preceeding description the novel design of this delivery system allows the liquid fluid to be pumped without it ever exiting the enclosed, disposable, sterile system comprising the fluid supply 7, cartridge 3 and fiber optic guide 31. Once one operative procedure is completed the supply 7, cartridge 3, and fiber optic guide 31 are disposed of and replaced by sterile ones thereof for the next operative procedure. Since the other non-disposable pumping mechanisms of the invention never contact the liquid they can be reused without the need for a separate sterilization procedure or the danger of infection of the sterile fluid. The gas supply system will now be described in more detail with particular reference to Figures 1-4. As shown in Figure 1, the gas supply 13 includes two separate sources 17 and 19. In the preferred form of the invention, the first source 17 is air from the atmosphere and the second source is gas from a pressurized container, such as a carbon dioxide tank. It should be noted that both sources 17 and 19 could be gases from sources other than those described. The first source 17 uses a diaphragm pump 37 to intake air from the atmosphere through filtered vent 155 and to exhaust it under pressure at port 157 into conduit 159. Conduit 159 is connected to a vapor collector 161 that, in turn, exhausts to conduit 25. Since the second gas source 19 originates, preferably, at a pressurized container 152, shown in Fig. 3, it is not necessary to use a separate pump to propel the gas. Therefore, the pressurized container exhausts directly into conduit 27. Both conduit 25, from the first source 17, and conduit 27, from the second source 19, are connected to conduit 15 through the solenoid activated valve 23. Valve 23 is energized to selectively couple either the first source 17 or the second source 19 with exhaust port 151. Exhaust port 151 is, in turn connected to port 141, located in the side wall 105 of the cartridge receptable 97, through conduit 15. In a preferred form of the invention a microswitch, located at the connection of conduit 27 with the gas source 19, will automatically activate valve 23 to connect the gas source 19 with the port 141. Thus alternate ones of the gas supply line of the cartridge 3. The solenoid activated valve 23 further includes a port 168 that is connected to a needle valve 120 through conduit 153 that acts as a bleed-for controlling the supply of fluid from pump 37. Because the gas supply 13 and the liquid supply 7 discharge through the cartridge 3 and the cartridge 3 is provided with flow rate monitory gauges 73 and 91, it is a very simple matter to regulate the fluid flow. Suitable controls 200 are provided to regulate the bleed of needle valve 120 the output of the pressurized container 152 and the speed of peristaltic motor 145. Thus, an exact output of gas, liquid or a combination thereof may be easily obtained.

Claims: A supply system for supplying gases and sterile liquids characterized by a disposable sterile cartridge (3) having a gas input (11), a liquid input (5), and a common output (29); a gas supply (13) external and separate from said cartridge connected to said gas input for delivering gas thereto; a liquid supply (7) connected to the said liquid input for delivering liquid thereto; means (37) for pressurizing the gas of said gas supply; and means (35) external to and separate from said cartridge and cooperating therewith to pump the sterile liquid of said liquid supply through the system whenever a supply of the sterile liquid is delivered to the liquid input (5) while maintaining the sterility of the liquid therein. A supply system according to claim 1, characterised in that said gas supply (13) includes a plurality of gas sources (17, 19). A supply system according to claim 2, characterised in that suitable control means (23) can select gas from one said plurality of gas sources to be delivered to the said gas input. A supply system according to claim 3, characterised in that the said control means include a valve (23). A supply system according to claim 4, characterised in that said valve (23) is solenoid activated. A supply system according to claim 1, characterised in that said means (37) for pressurizing said gas and said means (35) for pumping said liquid are controllable such that the flow rate of the gas and liquid to said common output (29) can be regulated. A supply system according to any one of claims 1 to 6, characterised by a pair of gauges (91, 73) formed in said cartridge (3) for indicating the flow rates of the gas and liquid delivered thereto. A supply system according to any one of claims 1 to 7, characterised by first conduit means (41) connecting said liquid input (5) to said common output (29) and a second conduit means (43) connecting said gas input (11) to said common output, said first conduit means including a length of exposed flexible conduit (63) extending externally of said cartridge; third conduit means (9) connecting the liquid supply (7) to said liquid input (5) for delivering liquid thereto; fourth conduit means (15) for delivering gas from the gas supply (13) to said gas input (11) and said pumping means (35) including a movable bearing assembly (125) that contacts said length of flexible conduit (63) to deform said conduit and thereby pump the liquid, and a means (145) for moving said bearing assembly. A supply system according to claim 8, characterised in that said pumping means (35) further includes a receptable (97) configured to receive said cartridge, said receptable including a port (141) engageable with said gas input of said cartridge to thereby connect said fourth conduit means (15) to said gas input. A supply system according to claim 8 or 9, characterised in that said cartridge further includes a bearing surface (143) on its outer periphery adjacent said length of flexible conduit (63) such that said moveable bearing deforms said length of conduit against said bearing surface. A supply system according to claim 10, characterised in that said bearing surface (143) is an arcuate recess (143) and said moveable bearing assembly includes a rotating wheel (127) mounted in said receptable (97) such that when said cartridge is inserted in said receptable said arcuate recess nests over the rotating wheel to trap said length of flexible conduit (63) therebetween. A supply system according to claim 11, characterised in that said rotating wheel, (127) further includes cylindrical bearings (131) arranged along the outer periphery thereof to contact said length of flexible conduit. A supply system according to claim 8, characterised in that said means for moving is a peristaltic motor (145). A supply system according to any one of claims 9 to 13, characterized in that said receptable (97) further includes a means (113, 115) to releasably lock said cartridge in said receptable. A supply system according to any one of claims 1 to 14 characterised in that said common output (29) is connected to a hollow fiber optic guide (31). A supply system according to any one of claims 8 to 15, characterised in that said common output (29) has a chamber (47) into which the first and second conduit means (41, 43) exhaust such that a mixture of gas and liquid can be exhausted through said common output. A supply system as claimed in any one of claims 2 to 16, characterised in that one of said plurality of gas sources (17) is the atmosphere and said means for pressurizing said gas is a diaphragm pump (37). A supply system according to any of claims 2 to 17, characterised in that one of said plurality of gas sources (19) is a gas from a pressurized container. A supply system according to any one of claims 8 to 18, characterised by control means (200) for regulating the flow rate of gas and liquid through said system. A supply system according to claim 19, characterised in that said control means (200) regulates the output of said pumping means (35) and said pressurizing means (37). A supply system according to claim 1, characterised in that the cartridge (3) further includes a filter (85) for filtering the gas delivered to the gas input (11). A supply system according to claim 21, wherein the filter (85) is included in said second conduit means (43). A disposable cartridge (3) for a sterile gas and liquid supply system, characterised by an upper section (39) having a first, second and third conduits (41, 43 and 45 respectively) formed therein, wherein said first conduit (41) includes a liquid input port (5) at one end thereof and said second (43) and third (45) conduits terminate at their respective one ends in a common chamber (47), said chamber including an output port (29); a lower section (49) integrally joined with said upper section including a hollow chamber (48), a gas input port (11) formed in said hollow chamber for receiving pressurized sterile gas; and means (59) cooperating with a pump for pumping sterile liquid through the cartridge in a first flexible conduit means (63) connecting said first and third conduits; second flexible conduit means (83) connecting said second conduit to said gas input port (11), whereby gas and liquid entering the cartridge through the gas input port (11) and liquid input port (5) respectively, are exhausted at said common output port (29). A disposable cartridge according to claim 23, characterised in that a length of said first flexible conduit (63) extends externally of said lower section (49) to thereby be exposed. A disposable cartridge according to claim 24, characterised in that said means cooperating with a pump (59) is in said lower section (49) and includes an arcuate recess that forms a semicircular cam surface, said length of first flexible conduit (63) being disposed adjacent said arcuate recess. A disposable cartridge according to claim 23, 24 or 25 characterised in that said second and third conduits (43, 45) include first and second gauge means (91, 73) for indicating the flow rates of the gas and liquid respectively. A disposable cartridge according to claim 26 characterised in that said first and second gauge means (91, 73) include floats (76, 75) disposed in said second and third conduits that cooperate with graduated markings (78, 77) formed on said upper section (39) to visually indicate said flow rates. A disposable cartridge according to any of claims 23 to 27, characterised in that a filter (85) is disposed in said second flexible conduit means.

Inventors: BROSS ROBERT MICHAEL, COOK KENNETH PRICE, BROSS, ROBERT, MICHAEL, COOK, KENNETH, PRICE
Applicants: SURGICAL LASER TECH, SURGICAL LASER TECHNOLOGIES, INC.
Application year: 1988
Main classification: A61B17
IPC codes: A61B18, A61M3, A61M13