Abstract:
In one aspect of the present invention, a sterilization system includes a feature for recharging a rechargeable member, such as a battery, battery pack or battery powered device. The system includes a closeable container defining an interior compartment and a gas discharge generator associated with and disposed in fluid communication with the container for generating a weakly ionized gas which generates an active (biocidal) species into the interior compartment. The system also includes first and second holders disposed in the interior compartment for holding the rechargeable member. The first and second holders have associated conductors for contacting and providing an electrical connection to first and second electrical terminals that are associated with the rechargeable member to permit recharging thereof.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to sterilization of an object and, in particular, to sterilization of one or more batteries, one or more battery packs and one or more battery powered devices, etc., and more specifically, relates to a sterilizing apparatus, such as a portable or modular system for sterilizing, disinfecting or decontamination of batteries, battery packs and battery powered devices, etc., utilizing non-thermal plasma and associate chemical methods while recharging the object in the same apparatus.  
       DESCRIPTION OF RELATED ART  
       [0002]     As is well know, the use of motorized devices is very prevalent in today&#39;s society and increasingly in the workplace. In a number of different environments, it is either a requirement (e.g., statutory requirement) or a part of standard protocol that the motorized devices be handled in a certain manner and in particular, there are a number of environments were sterilization and decontamination of the motorized devices are required.  
         [0003]     For example, the use of motorized devices for therapeutic and medical purposes is common. Various types of motorized or pneumatic devices are available for various particular applications. For example, drills and saws are typically used in orthopedic surgical procedures and biopsy procedures typically use coring devices to biopsy or sample bone marrow. While, many of these devices are corded, there is an increasing desire and it is becoming more common for the devices to be of a cordless type which offer greater mobility. For example, cordless surgical devices, such as drills, are frequently used in the operating room and avoid some of the problems associated with corded devices. Non-corded or cordless devices are typically not disposable in whole or in part.  
         [0004]     One of the disadvantages to using a cordless device is that the device typically has a replaceable (rechargeable) battery pack or runs on one or more batteries which must be sterilized before use. The most common types of sterilization techniques include the use of heat or steam at high temperatures; however, this in itself has a number of shortcomings. For example, exposure of the battery pack to high temperatures, such as those experienced in steam sterilization, can substantially reduce the life expectancy of the battery pack. In particular, a battery powered surgical drill typically has a removable, rechargeable battery pack; and although many of these battery packs can be steam sterilized, battery life can be extended by eliminating the sterilizing process and loading the battery into the drill aseptically. However, this is not always possible in a given environment.  
         [0005]     Another disadvantage is that battery capacity generally decreases upon exposure of the battery to high temperatures (e.g., &gt;250° F.), such as those observed in an autoclave environment for sterilizing the equipment and the battery pack. This is undesirable since this directly and adversely impacts the expected charge life of the battery and will result in lower powered recharged batteries and will require the batteries to be charged more often. Autoclave devices are one of the more common, if not the most common, means for sterilizing medical equipment, including motorized devices and their associated battery packs.  
         [0006]     Moreover, medical and surgical devices continue to become more sophisticated and expensive. Since these instruments typically must be sterilized before use, any instruments that are reusable must be made very durable to withstand repeated sterilizing cycles, and this results in considerable manufacturing costs being added. That is, the device must be formed of materials that will not degrade in the presence of those sterilizing agents in contemporary use. It is interesting to note that the grade of materials is typically not a function of the surgical procedure itself; a higher grade material is typically a function of the need to withstand repeated sterilizations. This inherently requires that more expensive materials and manufacturing techniques be utilized and that the sterilization-degradable components be adequately isolated from or compatible with such sterilizing agents.  
         [0007]     Current technology and practice requires that batteries and battery packs are recharged in one apparatus (a charger) and then transferred to a sterilization container and placed in an autoclave or other sterilizer before they can be used in surgery since the battery must be presented to the surgical team in a charged and sterile condition.  
         [0008]     It would therefore be highly desirable to provide a device having components of a grade suited to the specific surgical procedure, thereby reducing the costs associated with the device but at the same time, be able to be easily and readily sterilized. In addition, it is desirable to provide a system and method for sterilizing batteries, battery packs, and battery powered devices that overcome the disadvantages and shortcoming of conventional sterilizing equipment, such as high temperature autoclaves. It would also be desireable to provide a device that has the capability of recharging and sterilizing batteries and battery powered instruments in the same apparatus, thus reducing handling of the instrument. Further, it would also be desirable to simultaneously recharge and sterilize batteries and battery powered instruments in the same operation, thus gaining efficiency in time.  
       SUMMARY  
       [0009]     The present invention is directed to a system and method for sterilizing a rechargeable member, e.g., a battery, battery pack, or battery powered device, etc., by using a plasma discharge device.  
         [0010]     In one aspect of the present invention, a sterilization system includes a feature for recharging a rechargeable member, such as a battery, battery pack or battery powered device. The system includes a closeable container defining an interior compartment and a gas discharge generator associated with and disposed in fluid communication with the container for generating a weakly ionized gas into the interior compartment. The system also includes first and second holders disposed in the interior compartment for holding the rechargeable member. The first and second holders have associated conductors for contacting and providing an electrical connection to first and second electrical terminals that are associated with the rechargeable member to permit recharging thereof.  
         [0011]     In another embodiment, a modular sterilization system includes a feature for recharging a rechargeable member. The modular system includes at least one modular sterilization section divided into a plurality of compartments and a plurality of units. Each unit is dimensioned in size and shape to complement and be received within one of the plural compartments of the modular sterilization section. Each unit can be in the form of a closeable container that defines an interior compartment and includes: (a) a gas discharge generator associated with and disposed in fluid communication with the container for generating a weakly ionized gas into the interior compartment; and (b) means disposed within the interior chamber for recharging the rechargeable member.  
         [0012]     In yet another aspect of the present invention, a method of sterilizing and decontaminating a rechargeable member, such as a battery or battery pack, without a concatenate loss of battery capacity using a plasma discharge device having first and second electrodes includes the steps of: (a) producing plasma generated active sterilizing species by applying a voltage differential to the first and second electrodes to emit a plasma discharge; and (b) exposing the battery to the generated active sterilizing species. Furthermore, the sterilization of the battery can be combined with recharging of the rechargeable member simultaneously as the rechargeable member is sterilized by the active sterilizing species. According to one embodiment, the step of recharging the rechargeable member includes the steps of: (a) positioning the rechargeable member in the interior with first and second holders disposed in the interior for holding the rechargeable member, where the first and second holders have associated conductors; (b) forming an electrical connection between the conductors of the first and second holders and first and second electrical terminals that are associated with the rechargeable member to permit recharging thereof; and (c) operatively connecting the conductors to a power source that is activated for recharging of the rechargeable member.  
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]     The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention wherein like reference numbers refer to similar elements throughout the several views and in which:  
         [0014]      FIG. 1  is a cross-sectional view one exemplary system for sterilizing a rechargeable member utilizing a plasma discharge device according to the present invention;  
         [0015]      FIG. 2  is a cross-sectional view of another embodiment of a system for sterilizing a rechargeable member;  
         [0016]      FIG. 3  is a perspective view of an exemplary modular sterilization section in accordance with the present invention; and  
         [0017]      FIG. 4  is a perspective view of an exemplary modular sterilization system including two modular subsections connected together in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     As previously mentioned, one exemplary method of sterilizing battery powered medical equipment, including the batteries or battery pack themselves, is to place the object(s) into a high temperature environment and can include introducing some type of sterilizing agent, such as steam or fluid, etc., into the environment. For example, conventional sterilizers (steam autoclave, Ethylene Oxide, Sterrad™) are typically operated by placing a plurality of trays within the sterilization chamber. These sterilization systems require the trays to be isolated from their surrounding environment via a permeable filter media. Generally, the trays are wrapped in the permeable media. This isolation technique is necessary to maintain the sterility of the items when removing the tray from the sterilizer chamber for use elsewhere. The permeable filter media allows the sterilizing agent (e.g., chemical or steam) to diffuse and contact the items in the tray to be sterilized while substantially blocking the transfer of particles outside the media from reaching the contents protected therein.  
         [0019]     In accordance with the present invention, an in situ sterilization and decontamination system using a non-thermal plasma discharge is provided and advantageously, since the sterilization occurs at room temperatures, the system is particularly adapted to sterilize batteries, battery packs, and battery powered devices without a concatenate loss of battery capacity.  
         [0020]      FIG. 1  generally illustrates an in situ sterilization and decontamination system  100  according to one embodiment of the present invention. The system  100  is configured so that it can easily be used as a portable device and thus can be used in and transported between rooms in an office setting, such as a medical building, as well as being used in vehicle, vessel, aircraft, etc., as described below. In addition, the system  100  can be constructed to have a modular configuration similar to that disclosed in commonly assigned, U.S. patent application Ser. No. 11/042,359, filed on Jan. 24, 2005, which claims the benefit of U.S. Provisional Application Ser. No. 60/538,742, filed Jan. 22, 2004, which are hereby incorporated by reference in their entireties. This type of construction is described in greater detail below.  
         [0021]     The illustrated system  100  is constructed to include a housing (modular unit)  110  that contains the object to be sterilized, as well as the means for generating the plasma discharge. The illustrated housing  110  is in the form of a tray  112  and a complementary lid  114  that sealingly mates with the tray  112  so as to close off an interior compartment  116  that receives and contains the object. The tray  112  is thus open along one face and is defined by a floor  113  and side walls  115  that are joined to the floor  113 . The side walls  115  terminate upper edges  117  that sealingly contact and mate with the lid  114  so to seal the interior compartment  116 .  
         [0022]     In the present invention, the term “units” is generically used to describe any closable container such a tray with a lid, a closable box or a closable bag. Each unit may be adapted in size and shape based on the size and shape of the particular objects being treated.  
         [0023]     The lid  114  can be fabricated from a variety of materials (metallic, non-metallic, etc.) and is form fit to the mating tray  112 . A negative fit device (typically a gasket)  120  is preferably employed to form a seal, thereby keeping the active sterilizing species within the unit  110  to ensure sterility of the contents therein after the sterilization process is complete.  
         [0024]     The lid  114  includes a lower face or surface  122  that seats and seals against the tray  112 . According to one embodiment, a gas discharge generator  130  for producing a weakly ionized gas is disposed within and incorporated into the unit  110  so as to produce an active species, e.g., transient biocide, in the interior compartment  116  of the unit  110 . Accordingly, when the lid  114  is closed, the gas discharge generator  130  is contained within the interior compartment  116  so that the active species thereby is likewise contained in the interior compartment  116  in contact with the object.  
         [0025]     The use of active species produced by weakly ionized gas, such as plasma, as a means for sterilization is well known. Any type of conventional gas discharge reactor may be used to generate the weakly ionized gas, such as a corona or barrier discharge plasma reactor that will function as the gas discharge generator  130 . Several inventive generator configurations assigned to the same company as that of the present invention are disclosed in issued and pending related patent applications and are well suited for use in the present invention. Specifically, a capillary discharge plasma generator configuration is shown in U.S. Pat. No. 6,818,193, issued on Nov. 16, 2004, entitled “Segmented Electrode Capillary Discharge Non-Thermal Plasma Apparatus and Process for Promoting Chemical Reactions”. Alternative gas discharge configurations disclosed in pending applications include a Slot Discharge (described in U.S. Ser. No. 10/371,243, filed on Feb. 19, 2003, which claims the benefit of U.S. Provisional Application No. 60/358,340, filed Feb. 19, 2002) and Capillary-in-Ring Electrode Non-Thermal Plasma Generator and Method for Using the Same (described in provisional U.S. Application Ser. No. 60/538,743, filed on Jan. 22, 2004, the non-provisional application of which was filed on Jan. 24, 2005 and assigned U.S. Ser. No. 11/042,359 configurations. Each of these pending and issued patents are herein incorporated by reference in their entirety. These plasma generator configurations substantially suppress discharge transitions to the arc mode while increasing the surface area of the discharge or emissions from the reactor, however, the present invention may be modified for application using any type of gas discharge generator.  
         [0026]     Furthermore, the system  100  can incorporate the gas discharge generator  130  in the top lid  114  or it can be incorporated into the floor  113  of the tray  112  or even on one side wall  115  thereof so long as the active species produced by the gas discharge generator is directed to the object to be sterilized, decontaminated, etc.  
         [0027]     In accordance with the present invention, the object to be sterilized, decontaminated or otherwise treated is in the form of one or more batteries, a battery pack, or one or more battery powered devices. For purpose of illustration only, a single battery  200  is shown in  FIG. 1  as being the object contained within the interior space  116  for sterilization thereof. However, it will be understood that the object to be sterilized can equally be a plurality of batteries or a battery pack(s) or one or more battery powered devices, such as a cordless drill, or a combination thereof.  
         [0028]     The system  100  includes a first holder  210  for retaining one end of the object (e.g., battery  200 ) and a second holder  220  for retaining the other end of the object (e.g., battery  200 ), with the two holders  210 ,  220  being contained in the interior compartment  116  and spaced from one another. The first and second holders  210 ,  220  are constructed and positioned within the interior compartment  116  such that the battery  200  is securely held in place proximate the gas discharge generator  130  so that the object to be treated is exposed to the active species produced by the weakly ionized gas (plasma) emitted from the generator  130 . Thus, as shown in  FIG. 1  and according to one embodiment, the battery  200  is positioned proximate the gas discharge generator  130 . The first and second holders  210 ,  220  can have any number of different types of structures so long as they can sufficiently hold and retain the battery  200  in place as the system  100  is operated, transported, etc. For example, the first and second holders  210 ,  220  can be in the form of a pair of flexible prongs, arms, fingers, blocks, or the like that can grip the battery  200 .  
         [0029]     Preferably and in one embodiment, the holders  210 ,  220  are attached to a support surface, such as the floor  113  in such away that a degree of flexibility or bending capability is introduced into holders  210 ,  220  to permit the holders  210 ,  220  to be flexed apart so that the object  200  can be received therebetween and once this opening force is removed, the holders  210 ,  220  release stored energy and return to their original positions, thereby applying a biasing force (holding force) against the ends of the object (battery  200 ). In the case of a battery  200 , the holders  210 ,  220  likely seat against the oppositely charged terminals of the battery  200 . In the illustrated embodiment, the holders  210 ,  220  are in the form of upstanding flexible prongs that extend upwardly from the floor  113 . The holders  210 ,  220  can be formed of any number of different materials, including but not limited to, metals and non-metals, such as plastics, etc.] 
         [0030]     The holders  210 ,  220  should allow minimum contact with the battery  200  so that the maximum surface area of the battery is exposed to the active species.  
         [0031]     In yet another aspect of the present invention, the unit  110  is constructed so as to include a means for recharging the object that is sealingly contained within the interior compartment  116  for sterilization/decontamination thereof. This permits the object  200  to not only be subjected to the active species produced by the weakly ionized gas (plasma) emitted by the gas discharge generator  130  in the sealed unit  110  but also, the object  200  can be charged at the same time. In this embodiment, the holders  210 ,  220  are modified to perform such an operation and be operatively connected to a power source  230 . More specifically, the holder  210 ,  220  can be formed of a conductive material and be operatively connected, as by wires  232 , to oppositely charged terminals  234  of the power source  230 . In this manner, the holders  210 ,  220  act as oppositely charged power terminals that are placed in contact with like charged terminals of the object  200  to permit charging/recharging thereof. In other words, the holder  210  can function either as a positive (+) terminal or a negative (−) terminal, while the other holder  220  functions as the oppositely charged negative (−) or positive (+) terminal, respectively. When the terminals of the object  200  are placed in intimate contact with the positive and negative terminals associated with the holders  210 ,  220  and the power source  230  is activated, the object is charged at the same time that the gas discharge generator  130  operates and emits weakly ionized gas (plasma) into the interior chamber  116 , thereby producing the active species. Thus, by permitting the battery  200  to be recharged while undergoing sterilization, the time necessary to cycle batteries (e.g., for medical instruments) is decreased.  
         [0032]     When the holders  210 ,  220  are made of a non-conductive material (e.g., a dielectric material, such as plastic), the holders  210 ,  220  can include electrical contacts  212 ,  222 , respectively. In other words, conductive pads  212 ,  222  or the like can be incorporated into the structure of the holders  210 ,  220  such that the electrical terminals of the object  200  seat against and are conductive contact with the conductive pads  212 ,  222  when the object  200  is properly seated within and held by the holders  210 ,  220 . Conductive pads are designed to maintain minimal contact (preferably point contact) so that the maximum area of the battery  200  is exposed to the active species produced by the emitted plasma.  
         [0033]     When conductive elements, such as conductive pads  212 ,  222 , are included as part of the holders  210 ,  220 , the wires  232  are routed through the tray  114  to the power source  230  in such away that the interior chamber  116  remains sealed to the exterior (atmosphere). For example and according to one embodiment, the wires  232  are fed through vias  236  or the like that formed in the tray  112 . The vias  236  are of the type that seal easily so that when the wires  232  pass through the vias  236  to the power source  230 , the vias  236  can be sealed to the exterior. In the illustrated embodiment, the vias  236  are formed in the floor  113  of the tray  112 .  
         [0034]     In another embodiment illustrated in  FIG. 2 , when the holders  210 ,  220  are formed of a conductive material and thus function themselves as the electrical contacts, ends of the holders  210 ,  220  can extend through openings, such as slots, formed in the tray  112  and therefore, the wires  232  that extend between the holders  210 ,  220  and the terminals of the power source  230  can be located outside of the tray  112 . In this embodiment, the holders  210 ,  220  are sealed within the openings formed in the tray  112  as in the previous embodiment to thereby contain the weakly ionized gas (plasma) within the interior compartment  116 .  
         [0035]     As previously mentioned, the system  100  can be incorporated into a modular sterilization section. By way of example,  FIG. 3  shows and describes a modular sterilization system for use in a medical sterilization application where battery powered devices are used and/or sterilized batteries are needed. It is, however, contemplated and within the intended scope of the present invention to employ the modular sterilization system in other applications employing sterilization techniques where batteries are used and needed in a sterilized state, such as in a food processing environment, etc.  
         [0036]     An exemplary six unit modular sterilization section  300  in accordance with the present invention is shown in  FIG. 3 . The sterilization section may be designed, as desired, to accommodate any number of one or more units  110 . The modular sterilization section is designed with one or more compartments  105  adapted in size and shape to preferably receive only one unit  110 . Thus, the capacity of the modular sterilization section  100  is limited by the number of compartments  105 . By way of example, the modular sterilization section shown in  FIG. 3  has six compartments  105  capable of accommodating six or less units  110 , one compartment being adapted to receive a single unit. A control module  115  is installed to provide electricity (either DC or AC) to and vary the parameters for each of the individual units  110 . For instance, control module  115  may independently control for each unit  110  the type and quantity of an organic based reagent introduced therein, the period for sterilization, the sterilization cycles, and/or power level. It may also be desirable, but not necessary, to have the control module  115  monitor one or more parameters or conditions such as time of operation or unit status. Each unit, in turn, may be further divided or subdivided into nested compartments or sub compartments the sterilization parameters or conditions for each which again may be independently and individually controlled by the control module  115 .  
         [0037]     As discussed above, in a preferred embodiment, each unit  110  is adapted to produce a weakly ionized gas, e.g. plasma therein. A weakly ionized gas is a partially ionized gas composed of ions, electrons, and neutral species. This state of matter is produced by relatively high temperatures and/or relatively strong electric fields either constant (DC) or time varying (e.g., AC) electromagnetic fields. The weakly ionized gas is produced when free electrons are energized by electric fields in a background of neutral atoms/molecules. These electrons cause electron atom/molecule collisions which transfer energy to the atoms/molecules and form a variety of species which may include photons, metastables, atomic excited states, free radicals, molecular fragments, electrons, and ions. The neutral gas becomes partially or fully ionized and is able to conduct electric currents. The species are chemically active and/or able to physically modify the surface of materials and may therefore serve to form new chemical compounds and/or modify existing compounds.  
         [0038]     The generation of the weakly ionized gas requires the application of an electric field to an electrode. Thus, a modular sterilization section  100  adapted to sterilize objects in situ by exposure to a gas discharge requires that each compartment  105  be electrically connected to receive energy from a power source  310  in order to generate the electric field. Correspondingly, each unit also contains electronic circuitry connected to the electrode. In a preferred embodiment, an interface or adapter, for example, complementary male and female plugs, are provided on the respective unit  110  and corresponding compartment  105  so that when the unit is inserted into a compartment the male and female connectors automatically align to complete the connection. Alternatively, cable may extend from the compartment to be manually connected to a complementary port or outlet of the unit.  
         [0039]     The electric field will only be applied to those compartments for which the circuit has been closed or completed. That is, only those compartments loaded with and properly connected to an associated unit will generate an electric field. All empty compartments (i.e., those for which no unit has been inserted or the circuit has not been closed or completed) will not draw energy from the power source because the electrical circuit remains open. In this regard, the efficiency of the modular sterilization system is improved over that of the prior art in that only the necessary amount of power need to sterilize the particular number of loaded trays will be required.  
         [0040]     To increase concentrations of generated chemically active species, e.g., ions and free radicals, thereby accelerating and improving the overall destruction rates of undesirable chemical and/or biological contaminants an organic based reagent may be introduced into the plasma or weakly ionized gas, as described in detail in the pending application entitled “System and Method for Injection of an Organic Based Reagent in Weakly Ionized Gas to Generate Chemically Active Species”, U.S. patent application Ser. No. 10/407,141, filed on Apr. 2, 2003 (which claims the benefit of U.S. Provisional Application No. 60/369,654, filed Apr. 2, 2002) (having the same assignee as the present invention), said application being incorporated by reference in its entirety. The organic based reagent may be a combination of an organic additive (e.g., an alcohol or ethylene) mixed with an oxidizer (e.g., oxygen) prior to being introduced in the weakly ionized gas. Alternatively, the organic based reagent may be the injection of an organic additive alone in the weakly ionized gas while in the presence of air (non vacuum chamber) that inherently contains oxygen and serves as the oxidizer. Also, the organic based reagent may comprise an organic additive that itself includes an oxidizing component such as ethanol. In this situation the oxidizing component of the organic component when injected into the weakly ionized gas forms hydroxyl radicals, atomic oxygen or other oxidizing species that may be sufficient to eliminate the need for a supplemental oxidizer. Regardless of the organic based reagent used, the organic additive reacts with the oxidizer while in the presence of weakly ionized gas to initiate the production of chemically active species. The modular sterilizer may be adapted to be connected to a supply source for receiving the organic based reagent independently into each of the units  110 . This supply source may be disposed within or outside of the housing of the modular sterilization section depending on its size.  
         [0041]     As shown in  FIG. 4 , two or more slave modular sterilization sections  305  may be connected to the master modular sterilization section  100  to increase its capacity and together form a modular sterilization grid. In the example shown in  FIG. 2 , three modular sterilization sections (two slave units  305  and one master unit  100 ) are connected together to form a modular sterilization system or grid. The modular sterilization sections may be connected on any one or more of its sides to another modular sterilization section. Each of the multiple modular sterilization sections may have the same capacity, as shown in  FIG. 3  wherein each modular sterilization section has a six unit capacity. Alternatively, different capacity modular sterilizations sections may be connected together to form a modular sterilization system or grid.  
         [0042]     In the case of a battery powered device, the device itself, including the battery or battery pack, is placed within the interior chamber of the housing where it undergoes the above described sterilization process, as well as preferably, being recharged at the same time. Since the sterilization process is conducted at room temperatures as opposed to the high temperatures of conventional sterilizing devices, the capacity of the battery is not jeopardized. In addition, the use of a plasma discharge device to produce the sterilizing agent permit the overall design to be compact and permits the system to be portable and readily moved from one location to another location either by hand, vehicle, etc.  
         [0043]     Thus, while there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps which perform substantially the same function, in substantially the same way, to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.  
         [0044]     All references, publications, pending and issued patents are herein each incorporated by reference in their entirety.