Abstract:
A method for removing biofilm from a lumen of a medical implant is disclosed. The method includes the steps of inserting a plasma applicator into a lumen defined in a medical implant, the lumen having a proximal end portion and a distal end portion having an opening therein, positioning the plasma applicator adjacent a biofilm formation, generating a selectively reactive plasma effluent at the plasma applicator and directing the selectively reactive plasma effluent at the biofilm formation.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/780,369, filed on Mar. 13, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to plasma devices and processes for surface processing and tissue removal. More particularly, the disclosure relates to a system and method for generating and directing chemically reactive, plasma-generated species in a plasma device along with excited-state species (e.g., energetic photons) that are specific to the supplied feedstocks for treating tissue. 
     Background of Related Art 
     Electrical discharges in dense media, such as liquids and gases at or near atmospheric pressure, can, under appropriate conditions, result in plasma formation. Plasmas have the unique ability to create large amounts of chemical species, such as ions, radicals, electrons, excited-state (e.g., metastable) species, molecular fragments, photons, and the like. The plasma species may be generated in a variety of internal energy states or external kinetic energy distributions by tailoring plasma electron temperature and electron density. In addition, adjusting spatial, temporal and temperature properties of the plasma creates specific changes to the material being irradiated by the plasma species and associated photon fluxes. Plasmas are also capable of generating photons including energetic ultraviolet photons that have sufficient energy to initiate photochemical and photocatalytic reaction paths in biological and other materials that are irradiated by the plasma photons. 
     SUMMARY 
     Plasmas have broad applicability to provide alternative solutions to industrial, scientific and medical needs, especially workpiece surface processing at low temperature. Plasmas may be delivered to a workpiece, thereby affecting multiple changes in the properties of materials upon which the plasmas impinge. Plasmas have the unique ability to create large fluxes of radiation (e.g., ultraviolet), ions, photons, electrons and other excited-state (e.g., metastable) species which are suitable for performing material property changes with high spatial, material selectivity, and temporal control. Plasmas may also remove a distinct upper layer of a workpiece but have little or no effect on a separate underlayer of the workpiece or it may be used to selectively remove a particular tissue from a mixed tissue region or selectively remove a tissue with minimal effect to adjacent organs of different tissue type. 
     One suitable application of the unique chemical species is to drive non-equilibrium or selective chemical reactions at or within the workpiece to provide for selective removal of only certain types of materials. Such selective processes are especially sought in biological tissue processing (e.g., mixed or multi-layered tissue), which allows for cutting and removal of tissue at low temperatures with differential selectivity to underlayers and adjacent tissues. This is particularly useful for inactivation of biofilm-forming bacteria, removal of biofilms, mixtures of fatty and muscle tissue, debridement of surface layers and removing of epoxy and other non-organic materials during implantation procedures. 
     The plasma species are capable of modifying the chemical nature of tissue surfaces by breaking chemical bonds, substituting or replacing surface-terminating species (e.g., surface functionalization) through volatilization, gasification or dissolution of surface materials (e.g., etching). With proper techniques, material choices and conditions, one can remove one type of tissue entirely without affecting a nearby different type of tissue. Controlling plasma conditions and parameters (including S-parameters, V, I, Θ, and the like) allows for the selection of a set of specific particles, which, in turn, allows for selection of chemical pathways for material removal or modification as well as selectivity of removal of desired tissue type. The present disclosure provides for a system and method for creating plasma under a broad range of conditions including tailored geometries, various plasma feedstock media, number and location of electrodes and electrical excitation parameters (e.g., voltage, current, phase, frequency, pulse condition, etc.). 
     The supply of electrical energy that ignites and sustains the plasma discharge is delivered through substantially conductive electrodes that are in contact with the ionizable media and other plasma feedstocks. The present disclosure also provides for methods and apparatus that utilize specific electrode structures that improve and enhance desirable aspects of plasma operation such as higher electron temperature and higher secondary emission. In particular, the present disclosure provides for porous media for controlled release of chemical reactants. 
     Controlling plasma conditions and parameters allows for selection of a set of specific particles, which, in turn, allows for selection of chemical pathways for material removal or modification as well as selectivity of removal of desired tissue type. The present disclosure also provides for a system and method for generating plasmas that operate at or near atmospheric pressure. The plasmas include electrons that drive reactions at material surfaces in concert with other plasma species. Electrons delivered to the material surface can initiate a variety of processes including bond scission, which enables volatilization in subsequent reactions. The electron-driven reactions act synergistically with associated fluxes to achieve removal rates of material greater than either of the reactions acting alone. 
     A method for removing biofilm from a lumen of a medical implant is contemplated by the present disclosure. The method includes the steps of inserting a plasma applicator into a lumen defined in a medical implant, the lumen having a proximal end portion and a distal end portion having an opening defined therein, positioning the plasma applicator adjacent a biofilm formation, generating a selectively reactive plasma effluent at the plasma applicator and directing the selectively reactive plasma effluent at the biofilm formation. The plasma is further applied along the entire length of lumen to restore the lumen to a bacteria-free condition similar its new condition. 
     A method for removing biofilm from a lumen of an endotracheal tube is also contemplated by the present disclosure. The method includes the steps of inserting a plasma applicator into a lumen of an endotracheal tube and positioning the plasma applicator adjacent a biofilm formation. The plasma applicator includes a shaft having a proximal portion and a deflectable distal portion and a lumen defined therein terminating in an opening at a distal end of the distal portion, the lumen being in fluid communication with an ionizable media source and at least one electrode disposed at the distal portion and coupled to a power source. The method also includes the steps of generating a selectively reactive plasma effluent at the plasma applicator and directing the selectively reactive plasma effluent at the biofilm formation and applying the plasma along the full length of the lumen to inactivate remaining and dispersed biofilm-forming bacteria. 
     A method for removing biofilm from a lumen of an endotracheal tube is also disclosed. The method includes the steps of inserting a seal at a distal end portion of an endotracheal tube, inserting a plasma applicator into a lumen of an endotracheal tube and positioning the plasma applicator adjacent a biofilm formation. The method further includes the steps of supplying ionizable media and the at least one precursor feedstock to the plasma applicator, igniting the ionizable media and the at least one precursor feedstock at the plasma applicator to form a selectively reactive plasma effluent and directing the selectively reactive plasma effluent at the biofilm formation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure, wherein: 
         FIG. 1  is a schematic diagram of a plasma system according to the present disclosure; 
         FIG. 2  is a schematic view of a plasma device according to the present disclosure; 
         FIG. 3  is a cross-sectional view of the plasma device of  FIG. 2  along lines  3 - 3 ; 
         FIG. 4  is an internal cross-sectional view of an implanted endotracheal tube; 
         FIG. 5  is an internal cross-sectional view of the endotracheal tube of  FIG. 4  and the plasma device of  FIG. 2  inserted therein according to the present disclosure; and 
         FIG. 6  is a flow chart of a method according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Plasmas are generated using electrical energy that is delivered as either direct current (DC) electricity or alternating current (AC) electricity at frequencies from about 0.1 hertz (Hz) to about 100 gigahertz (GHz), including radio frequency (“RF”, from about 0.1 MHz to about 100 MHz) and microwave (“MW”, from about 0.1 GHz to about 100 GHz) bands, using appropriate generators, electrodes, and antennas. Choice of excitation frequency, the workpiece, as well as the electrical circuit that is used to deliver electrical energy to the circuit affects many properties and requirements of the plasma. The performance of the plasma chemical generation, the delivery system and the design of the electrical excitation circuitry are interrelated as the choices of operating voltage, frequency and current levels (as well as phase) effect the electron temperature and electron density. Further, choices of electrical excitation and plasma device hardware also determine how a given plasma system responds dynamically to the introduction of new ingredients to the host plasma gas or liquid media. The corresponding dynamic adjustment of the electrical drive, such as via dynamic match networks or adjustments to voltage, current, or excitation frequency may be used to maintain controlled power transfer from the electrical circuit to the plasma. 
     Referring initially to  FIG. 1 , a plasma system  10  is disclosed. The system  10  includes a plasma device  12  that is coupled to a power source  14 , an ionizable media source  16  and a precursor source  18 . Power source  14  includes any suitable components for delivering power or matching impedance to plasma device  12 . More particularly, the power source  14  may be any radio frequency generator or other suitable power source capable of producing power to ignite the ionizable media to generate plasma. The plasma device  12  may be utilized as an electrosurgical pencil for application of plasma to tissue and the power source  14  may be an electrosurgical generator that is adapted to supply the device  12  with electrical power at a frequency from about 0.1 MHz to about 2,450 MHz and in another embodiment from about 1 MHz to about 160 MHz. The plasma may also be ignited by using continuous or pulsed direct current (DC) electrical energy. 
     The precursor source  18  may be a bubbler or a nebulizer configured to aerosolize precursor feedstocks prior to introduction thereof into the device  12 . The precursor source  18  may also be a micro droplet or injector system capable of generating predetermined refined droplet volume of the precursor feedstock from about 1 femtoliter to about 1 nanoliter in volume. The precursor source  18  may also include a microfluidic device, a piezoelectric pump, or an ultrasonic vaporizer. 
     The system  10  provides a flow of plasma through the device  12  to a workpiece “W” (e.g., tissue). Plasma feedstocks, which include ionizable media and precursor feedstocks, are supplied by the ionizable media source  16  and the precursor source  18 , respectively, to the plasma device  12 . During operation, the precursor feedstock and the ionizable media are provided to the plasma device  12  where the plasma feedstocks are ignited to form plasma effluent containing ions, radicals, photons from the specific excited species and metastables that carry internal energy to drive desired chemical reactions in the workpiece “W” (e.g., tissue) or at the surface thereof. The feedstocks may be mixed upstream from the ignition point or midstream thereof (e.g., at the ignition point) of the plasma effluent, as shown in  FIG. 1  and described in more detail below. 
     The ionizable media source  16  provides ionizable feedstock to the plasma device  12 . The ionizable media source  16  is coupled to the plasma device  12  and may include a storage tank and a pump (not explicitly shown). The ionizable media may be a liquid or a gas such as argon, helium, neon, krypton, xenon, radon, carbon dioxide, nitrogen, hydrogen, oxygen, etc. and their mixtures, and the like, or a liquid. These and other gases may be initially in a liquid form that is gasified during application. 
     The precursor source  18  provides precursor feedstock to the plasma device  12 . The precursor feedstock may be either in solid, gaseous or liquid form and may be mixed with the ionizable media in any state, such as solid, liquid (e.g., particulates or droplets), gas, and the combination thereof. The precursor source  18  may include a heater, such that if the precursor feedstock is liquid, it may be heated into gaseous state prior to mixing with the ionizable media. 
     In one embodiment, the precursors may be any chemical species capable of forming reactive species such as ions, electrons, excited-state (e.g., metastable) species, molecular fragments (e.g., radicals) and the like, when ignited by electrical energy from the power source  14  or when undergoing collisions with particles (electrons, photons, or other energy-bearing species of limited and selective chemical reactivity) formed from ionizable media  16 . More specifically, the precursors may include various reactive functional groups, such as acyl halide, alcohol, aldehyde, alkane, alkene, amide, amine, butyl, carhoxlic, cyanate, isocyanate, ester, ether, ethyl, halide, haloalkane, hydroxyl, ketone, methyl, nitrate, nitro, nitrile, nitrite, nitroso, peroxide, hydroperoxide, oxygen, hydrogen, nitrogen, and combination thereof. In embodiments, the chemical precursors may be water, halogenoalkanes, such as dichloromethane, tricholoromethane, carbon tetrachloride, difluoromethane, trifluoromethane, carbon tetrafluoride, and the like; peroxides, such as hydrogen peroxide, acetone peroxide, benzoyl peroxide, and the like; alcohols, such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, alkalises such as NaOH, KOH, amines, alkyls, alkenes, and the like. Such chemical precursors may be applied in substantially pure, mixed, or soluble form. 
     The precursors and their functional groups may be delivered to a surface to react with the surface species (e.g., molecules) of the workpiece “W.” In other words, the functional groups may be used to modify or replace existing surface terminations of the workpiece “W” or materials disposed thereon. The functional groups react readily with the surface species due to their high reactivity and the reactivity imparted thereto by the plasma. In addition, the functional groups are also reacted within the plasma volume prior to delivering the plasma volume to the workpiece. 
     Some functional groups generated in the plasma can be reacted in situ to synthesize materials that subsequently form a deposition upon the surface. This deposition may be used for stimulating healing, killing bacteria, and increasing hydrophilic or hydroscopic properties. In addition, deposition of certain function groups may also allow for encapsulation of the surface to achieve predetermined gas/liquid diffusion, e.g., allowing gas permeation but preventing liquid exchange, to bond or stimulate bonding of surfaces, or as a physically protective layer. 
     With reference to  FIGS. 1 and 2 , the precursor source  18  and the ionizable media source  16  may be coupled to the plasma device  12  via tubing  114  and  113 , respectively. The tubing  114  and  113  may be combined into unified tubing to deliver a mixture of the ionizable media and the precursor feedstock to the device  12  at a proximal end thereof. This allows for the plasma feedstocks, e.g., the precursor feedstock and the ionizable gas, to be delivered to the plasma device  12  simultaneously prior to ignition of the mixture therein. 
     In another embodiment, the ionizable media source  16  and the precursors source  18  may be coupled to the plasma device  12  via the tubing  114  and  113  at separate connections, such that the mixing of the feedstocks occurs within the plasma device  12  upstream from the ignition point. In other words, the plasma feedstocks are mixed proximally of the ignition point, which may be any point between the respective sources  16  and  18  and the plasma device  12 , prior to ignition of the plasma feedstocks to create the desired mix of the plasma effluent species for each specific surface treatment on the workpiece “W.” 
     In a further embodiment, the plasma feedstocks may be mixed midstream, e.g., at the ignition point or downstream of the plasma effluent, directly into the plasma. It is also envisioned that the ionizable media may be supplied to the device  12  proximally of the ignition point, while the precursor feedstocks are mixed therewith at the ignition point. In a further illustrative embodiment, the ionizable media may be ignited in an unmixed state and the precursors may be mixed directly into the ignited plasma. Prior to mixing, the plasma feedstocks may be ignited individually. The plasma feedstock is supplied at a predetermined pressure to create a flow of the medium through the device  12 , which aids in the reaction of the plasma feedstocks and produces a plasma effluent. The plasma according to the present disclosure is generated at or near atmospheric pressure under normal atmospheric conditions. 
     The system  10  further includes a suction source  15  (e.g., negative pressure source) configured to siphon tissue and unreacted components from the treatment site. The suction source  15  may be a vacuum pump, fan, circulator, and the like and is coupled to the device  12 . 
     With reference to  FIGS. 2 and 3 , the device  12  is shown as a plasma applicator  100 . The applicator  100  includes a handle  101  and a longitudinal shaft  102  coupled thereto. The shaft  102  includes a proximal portion  104  coupled to the handle  101  and a distal portion  106 . The catheter shaft  102  includes a plasma lumen  103  defined therein and extending the entire length thereof and terminating in an opening  105  at distal end of the distal portion  106 . The shaft  102  may have a diameter from about 5 mm to about 10 mm allowing the applicator  100  to be inserted through operating ports for application of the plasma effluent  32  at the operating site during laparascopic procedures or through natural body orifices. In another embodiment, the applicator  100  may be configured for use within or accompanied by a flexible endoscope. 
     The catheter shaft  102  may slidably disposed within the handle  101  allowing for the longitudinal movement of the catheter shaft  102  (e.g., extension and retraction). The catheter shaft  102  may include a stop or a shoulder at a proximal end thereof that abuts a complementary shoulder or stop disposed within the handle  101  to prevent further extension of the catheter shaft  102 . 
     The device  12  also includes controls  111  (e.g., toggle switch, trigger, etc.) coupled to the power source  14  and the ionizable media source  16 . Upon actuation, the controls  111  regulate the flow of ionizable media from the ionizable media source  16  and the precursors source  18  as well as the flow of power from the power source  14 , such that the ionizable media flowing through the lumen  103  is ignited therein and is ejected from the opening  105  to form the plasma effluent  32 . 
     The handle  101  includes a rotating assembly  123  for controlling the rotational movement of the distal portion  106  about a longitudinal axis of the catheter shaft  112 . The rotating assembly  123  engages one or more gears (not shown) which are attached to the catheter shaft  112 . In one embodiment, the ratio of rotation of rotating assembly  123  to distal portion  106  is 1:1, however, it is contemplated that a different gearing structure may be incorporated to increase or decrease the rotational ratio depending upon a particular purpose. 
     In one embodiment, the distal portion  106  is configured for controlled deflection. A pull-wire  107  ( FIG. 3 ) or another suitable actuation mechanism extends from the handle  101  at the proximal end of the catheter  100  through a lumen in the catheter shaft  102  and is fastened to the distal portion  106 . The pull-wire  107  is movable from a first generally relaxed position wherein the distal portion  106  is disposed in a generally longitudinally-aligned position relative to the proximal portion  104  to a second retracted or tensed position wherein the distal portion  106  flexes (e.g., deflects) from the proximal portion  104  at a desired angle as shown in  FIG. 2 . 
     The distal portion  106  is constructed to be more flexible than the proximal portion  104 , such that when the handle  101  is pulled back or otherwise actuated, the pull-wire bends the distal portion  106  from an undeflected position to a deflected position. In particular, the proximal portion  104  may include a wire or other support materials (not shown) therein to provide tensile strength to the catheter shaft  102  while still maintaining flexibility for maneuvering through a vascular system. The distal portion  106  is formed from a flexible biocompatible material such as polytetrafluoroethylene, polyurethane, polyimide, and the like to allow for maneuverability thereof. 
     The applicator  100  includes two or more electrodes  108  and  110  disposed at the distal portion  106 . The electrodes  108  and  110  may be formed from a conductive material and have a ring-like shape. The electrodes  108  and  110  may be disposed over the distal portion  106  to provide for capacitive coupling with the ionizable media. In another embodiment, the electrodes  108  and  110  may be formed as needle electrodes (e.g., pointed tip) and may be disposed within the distal portion  106 . 
     The electrodes  108  and  110  are coupled to conductors (not shown) that extend through the catheter shaft  102  and are connected to the power source  14  via electrical connectors  112 . The catheter shaft  102  is also coupled to the ionizable media source  16  via gas tubing  114  and to the precursors source  16  via tubing  113 . The ionizable media source  16  and the precursors source  16  may include various flow sensors and controllers (e.g., valves, mass flow controllers, etc.) to control the flow of ionizable media to the applicator  100 . In particular, the lumen  103  is in gaseous and/or liquid communication with the ionizable media source  16  and the precursors source  18  allowing for the flow of ionizable media and precursor feedstocks to flow through the catheter shaft  102  to the distal portion  106 . The ionizable media in conjunction with the precursor feedstocks is ignited by application of energy through the electrodes  108  and  110  to form plasma effluent  32  exiting through the opening  105 . 
     The applicator  100  also includes a suction lumen  150  coupled to the negative pressure source  19 . This allows for the removal of unreacted feedstocks and debris particles to be removed from the application site. The lumen  150  may be incorporated into the shaft  102  ( FIG. 3 ) or may be a separate tube  152  coupled in parallel to the shaft  102  ( FIG. 2 ). The tube  152  may include a distal portion  128  that extends distally past the distal portion  106 . The lumen  150  may be coupled to a suction source  15  via tubing  115 . 
     The applicator  100  may also include a temperature sensor  130  at the distal portion  106 . The temperature sensor  130  may be a thermistor, a thermocouple, or any other type of suitable temperature sensor that is coupled to the power source  14 . The temperature sensor  130  provides continual temperature readings to the power source  14 , which then adjusts the energy supplied to the plasma feedstocks to regulate the energy output of the plasma effluent  32 . 
     The applicator  100  is suitable for removing biofilms from various type of medical implants, namely, lumens of various implants (e.g., endotracheal tubes). Tracheal tubes provide a source for bacterial growth within lumens where environment is warm and moist providing ideal conditions for bacterial growth. Since the lumens are inaccessible by the immune system the bacterial growth advances into biofilms that cannot be eliminated by conventional chemical treatments. Growth of the biofilms inside the tracheal tubes leads to costly tube replacement procedures. The applicator  100  generates the plasma effluent  32  that removes the biofilm and deactivates bacterial contamination within the endotracheal tube. 
       FIG. 4  shows an exemplary embodiment of an endotracheal tube  311  implanted in a trachea  319 . The endotracheal tube  311  includes tubing  313  having a distal end portion  302  adapted to be orally inserted in a patient&#39;s trachea  319  and a proximal end portion  304  adapted to protrude from the patient&#39;s mouth. The tubing  313  defines a lumen  317  therethrough and is sufficiently flexible to bend and conform to the patient&#39;s anatomy, but has sufficient structural integrity to prevent kinking and collapsing during insertion. The lumen  317  terminates in an opening  303  at the distal end portion  302 . The tubing  313  may be formed from a medical grade silicone plastic material that is stable at a temperature range from about 0° C. to about 60° C. Tube  313  may be formed from a single piece of silicone plastic of extruded construction. 
     As illustrated in  FIG. 4 , the tubing  313  is flexible and conforms to the patient&#39;s anatomy when inserted. The tubing  313  is resistant to collapse while being intubated or after being in place for great lengths of time. The distal portion  302  of the endotracheal tube  311  is provided with an expandable cuff or balloon  331  of a gas impervious material such as a thin sheet of silicone material of the type described above. Cuff  331  may be inflated by a pilot balloon or a syringe (not shown) in gaseous communication therewith (e.g., connected to the cuff  331  by an external tube and internal passage in the wall of tube  13 ). When the cuff  331  is inflated to engage the wall of trachea  319 , air or other gases pass to and from a patient&#39;s lungs,  327 ,  329 , through the bronchi  323 ,  325  and through the lumen  317  of the tube  311 . The proximal end  304  of the tube  311  is adapted to be connected to a ventilator or oxygen source and/or a suction device. 
     With reference to  FIGS. 5 and 6 , a biofilm removal method using the applicator  100  is discussed.  FIG. 5  illustrates the endotracheal tube  311  and  FIG. 6  illustrates a flow chart of a method for removing the biofilm therefrom. In step  400 , the opening  303  is selectively blocked using a seal  306 , which may be temporarily adhered within the lumen  317 . The seal  306  may be delivered to the distal end portion  302  using a variety of endoscopic instruments and techniques that provide for visual access to anatomical lumens. The seal  306  blocks the opening  303  to prevent bacteria released from the surface by the plasma effluent  32  to be introduced into the patient&#39;s lungs  327  and  329 . 
     Seal  306  may have a profile configured to match the opening  303  thereby sealing the opening  303 . The seal  306  may be disposed within the lumen  306 . In embodiments, the seal  306  may abut against an interior lip of the opening  303  such that the seal  306  does not pass beyond opening  303 . Seal  306  may be secured to the lumen  317  via a living hinge or any other pivotable attachment that enables the seal  306  to move within the lumen  317  with minimum contact. The seal  306  may be made of polypropylene or any other suitable polymer from which the living hinge element may be formed. 
     Forward movement/pressure by the applicator  100  holds seal  306  against the opening lip of  303 . When plasma is deactivated, the applicator  100  may be withdrawn from the lumen  306  and/or away from the seal  306  to enable air to pass therethrough thereby allowing for intermittent respiration for the patient. In embodiments, the applicator  100  may include a contact sensor (e.g., pressure actuated limit switch) at the distal portion  106 , which is coupled to the controls  111 . The contact sensor acts as a safety lockout preventing plasma activation via the controls  111  when the contact sensor is disengaged from the seal  306 . This ensures that the seal  306  is closed prior to activation and subsequent application of the plasma plume. 
     In step  402 , the applicator  100  is inserted into the lumen  317 . The distal portion  106  may be deflected to direct the plasma effluent  32  toward the biofilm. In one embodiment, the deflection may be from about 0° to about 45° with respect to a longitudinal axis defined by the shaft  102 . In step  404 , the ionizable media along with precursors is supplied to the applicator  100  and is ignited therein to form the plasma effluent  32 . In one embodiment, the ionizable media may be argon, helium or a mixture thereof and the precursors may be hydrogen peroxide, water, oxygen, nitrogen or mixtures thereof. 
     In step  406 , the applicator  100  is moved across the lumen  317  ensuring that the plasma effluent  32  is directed at walls thereof to remove the biofilm. As biofilm is removed, bacteria and other debris is removed from the treatment site through the suction lumen  150  via suction source  15 . The temperature of the plasma effluent  32  is from about 60°, allowing the plasma to be used within the silicone tube  311  without damaging the walls thereof. The relatively low temperature of the plasma effluent  32  does not affect its ability to remove biofilm, since the primary effect on bacteria is due to the chemical reactivity of the plasma constituents (e.g., ionized plasma feedstocks). The precursors supplied to the applicator  100  are specifically chosen to generate a selectively reactive plasma effluent  32 . In other words, the precursors, when ignited, produce a plasma effluent  32  that interacts with bacteria, and has little to no effect on material of the tube  311 . 
     The emissions may be measured in the plasma effluent  32  by an optical spectrometer (not shown) including an optical fiber positioned to capture the emission from the plasma effluent  32  at the area of contact with the lumen  317 . In embodiments, nuclear magnetic resonance (NMR) and/or laser induced florescence (LIF) devices may be used to evaluate the gas evacuated from the tube  128  at the location of suction source  15 . In further embodiments, a second plasma ignition point in the effluent from tube  128  may be ignited enabling the emissions to be monitored in the plasma effluent  32  directly at the optical spectrometer at suction source  15 . 
     In step  408 , the effect of the plasma treatment is monitored by measuring the spectra of the application of the plasma effluent  32 . The spectra are observed for specific emissions related to the destruction of the biofilms. The spectra are used to confirm the destruction of the biofilm and are used as a feedback mechanism for advancing of the applicator  100 . In particular, the spectra are used by the user to determine when a specific region of the lumen  317  is substantially cleared of the biofilm allowing the user to determine when the applicator  100  may be advanced further into the lumen  317  and additional biofilm may be removed. The distal portion  106  may also be advanced by extending the catheter shaft  102  in a distal direction. Additionally, the spectra may be used to determine when the lumen  317  is substantially clear of the biofilm and application of the plasma effluent  32  may be terminated. In step  410 , the applicator  100  is extracted from the lumen  317  and the seal  306  is removed, restoring the functionality of the tube  311 . 
     Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure. In particular, as discussed above this allows the tailoring of the relative populations of plasma species to meet needs for the specific process desired on the workpiece surface or in the volume of the reactive plasma.