Mist generator for sterilizing forced hot air intraoperative patient warmer with improved sterility

Abstract

A mist generator improves sterility of blowers having controlled forced air for patient warmers and lifters. The mist generator has a main body including a top wall with an opening, that traverses into a chamber adapted to receive a disinfectant, side walls and a bottom wall. The main body further includes an inlet duct adapted for attachment to a first hose which, in turn, is adapted for attachment to an output opening of the blower for delivery into the chamber of forced air carrying misted disinfectant. The main body also includes an output duct adapted for attachment to a second hose which, in turn, is adapted for attachment to an inlet opening of the blower for delivery of disinfectant misted air through internal components of the blower. The mist generator improves sterility of the blower, thereby mitigating microbial contamination of patient warmers and lifters, and hospital environments.

Claims

1. A mist generator for improved sterility of blowers having controlled forced air delivery, consisting of: a) a main body having a top wall with an opening, the opening traversing into a chamber adapted to receive a disinfectant, side walls and a bottom wall; b) an inlet duct adapted for attachment to a first hose which in turn is adapted for attachment to an output opening of a blower for delivery of forced air into the chamber to carry disinfectant misted air; c) an output duct adapted for attachment to a second hose which in turn is adapted for attachment to a blower inlet opening of the blower for delivery of disinfectant misted air through internal components of the blower; whereby the mist generator improves sterility of the blower to mitigate microbial contamination of patient warmers and lifters and hospital environments.

2. The mist generator as recited by claim 1, wherein the blower is part of a non-closed circuit and said first and second hoses have quick release couplings configured to be disconnected from said mist generator and connected to a patient warmer.

3. The mist generator as recited by claim 1, wherein the blower has microprocessor controlled air heating capability for delivery of heated forced air, and said disinfectant is adapted to evaporate due to the heated forced air to yield misted air containing disinfectant.

4. The mist generator as recited by claim 3, wherein said disinfectant is a volatile liquid component that is adapted to vaporize as forced air blows over said disinfectant.

5. The mist generator as recited by claim 3, wherein said disinfectant is a volatile liquid component saturated within a substrate and said liquid vaporizes and escapes said substrate as forced air blows over said substrate.

6. The mist generator as recited by claim 1 comprising a transducer facilitating formation of said disinfectant mist.

7. The mist generator as recited by claim 1, wherein said disinfectant is an aqueous solution.

8. The mist generator as recited by claim 1, wherein said disinfectant is an alcohol solution.

9. The mist generator as recited by claim 1 comprising a sterilization cycle set to run for a preselected time period.

10. The mist generator as recited by claim 1, wherein said mist generator is disposable.

11. The mist generator as recited by claim 1, wherein the inlet duct and the output duct are located on opposite side walls.

12. The mist generator as recited by claim 1, wherein the bottom wall includes a bottom opening with a removable bottom cover.

13. The mist generator as recited by claim 1 comprising a microprocessor for controlling the amount of disinfectant delivered for atomization into the chamber of the mist generator.

14. The mist generator as recited by claim 1, comprising a soft diaphragm located on said opening of said top wall through which fluids are to be introduced with a syringe needle.

15. The mist generator as recited by claim 1 wherein said disinfectant is contained in a capsule adapted to be inserted within said chamber of said mist generator.

16. The mist generator as recited by claim 15, wherein said disinfectant is a liquid and said capsule is a spray capsule, wherein said chamber of said mist generator includes a spray activator for release of said disinfectant as a spray within said chamber of said mist generator.

17. An improvement in sterilizing non-closed circuit patient warmers, the improvement consisting of a mist generator containing a disinfectant constructed having an inlet duct traversing to a chamber containing the disinfectant; an output duct adapted for attachment to a second hose which in turn is adapted for attachment to a blower inlet opening of the blower and an output duct from said chamber, allowing for delivery of disinfectant misted air through internal components of the blower, the inlet opening of the blower and the output duct from the chamber, together with a first hose connected to and in communication with a blower outlet opening and said inlet duct of said chamber, adapted to form a closed circuit and run a sterilization cycle for a preselected time period.

18. The improvement as recited by claim 17, wherein said preselected time period is less than 15 minutes.

19. The improvement as recited by claim 17, wherein the mist generator comprises a soft diaphragm through which fluids are to be introduced with a syringe needle.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention will be more fully understood and further advantages will become apparent when reference is had to the following detailed description of the preferred embodiments of the invention and the accompanying drawing, in which:

(2) FIG. 1 illustrates an embodiment of a system for delivering warm air to patient beds and blankets in a closed circulating circuit;

(3) FIG. 2 illustrates an embodiment of the blower with air warmer machinery and flexible tubes being sterilized by the antimicrobial mist generator;

(4) FIG. 3 illustrates details of an embodiment of the microprocessor controlled blower with input port 202 and an output port, both provided with HEPA filters;

(5) FIG. 4 illustrates an embodiment of the antimicrobial mist generator;

(6) FIG. 5 illustrates an embodiment of the patient mattress or blanket;

(7) FIG. 6 illustrates an embodiment of the sterilization process of the patient bed or blanket prior to disposal;

(8) FIG. 7 illustrates another embodiment of the microprocessor controlled antimicrobial mist generator;

(9) FIG. 8 illustrates the embodiment of FIG. 7 connected to a blower with air warmer machinery and flexible tubes being sterilized by the antimicrobial/disinfectant mist generator;

(10) FIG. 9a illustrates another embodiment of the antimicrobial mist generator;

(11) FIG. 9b illustrates another embodiment of a spray capsule/cartridge adapted to be inserted within the mist generator of FIG. 9a;

(12) FIG. 9c illustrates an embodiment of a capsule/cartridge adapted to be inserted within the mist generator of FIG. 9a;

(13) FIG. 9d illustrates another embodiment of a capsule/cartridge adapted to be inserted within the mist generator of FIG. 9a;

(14) FIG. 10 illustrates the embodiment of FIG. 9 connected to a blower with air warmer machinery and flexible tubes being sterilized by the antimicrobial/disinfectant mist generator; and

(15) FIG. 11 illustrates another embodiment of the antimicrobial mist generator.

DETAILED DESCRIPTION OF THE INVENTION

(16) The objective of the invention is to provide a mist generator for delivering an antimicrobial or disinfectant mist to a blower in order to sterilize the blower for later use with patent warmers and/or patient lifters, thereby decreasing the possibility of patients suffering infections and hospital workers in the operating room being exposed to infecting microbes. The subject mist generator is intended to perform internal sterilization of the blower and hoses of a patient warmer or lifter. As the mat is single use and disposable, it is not necessary for the mist generator to disinfect it, though the generator may be employed when the mat is connected. The generator must be used in a closed circuit, although that may be only temporary. Disinfectant or antimicrobial is introduced into the chamber and vaporized by warm air circulated by the blower. After the disinfectant sterilizes the inside surfaces of the blower and hoses, an aliquot of water is introduced into the chamber and is similarly vaporized, taking up the disinfectant residue. A dry desiccant is then appointed to be introduced into the chamber and absorbs the mist. After the mist is absorbed and the system is clean and dry, the blower is then turned off. The mist generator is removed from the system and discarded, if it is disposable; or, if not disposable, is simply emptied.

(17) The subject antimicrobial or disinfectant mist generator is operable as a stand-alone internal sterilizer for non-closed-circuit patient warmers. Internal sterilization of the patient warmers through use of the antimicrobial mist generator mitigates infection risks caused from contaminated air flow of the patient warmer. An outflow/output duct of the antimicrobial mist generator is attached to a flexible hose that connects to an air inflow duct of any non-closed circuit device, temporarily making it run as a closed circuit and allowing internal sterilization, including drying, without releasing disinfectant vapor into the hospital environment. The antimicrobial mist generator, is preferably, but not necessarily, disposable; and achieves the internal sterilization that is currently impossible with patient heating devices now in use. The FDA has recommended regular cleaning of patient heating devices, therefore the subject antimicrobial mist generator provides an add-on stand-alone internal sterilizer for ready compliance with FDA recommendations. In one embodiment, the antimicrobial mist generator avoids a port into its chamber that could be opened for filling, and instead is constructed to have a soft diaphragm through which fluids are introduced with a needle and syringe, similar to medicine vials, in order to avoid contamination. Desiccant is then introduced into the chamber via a removable port.

(18) The term non-closed circuit or open circuit refers generally to blowers having an outlet air duct for delivering forced air to a perforated blanket and an air inlet duct for pulling air from the atmosphere into the blower and no return of warm air to the blower. As used herein, the term closed circuit refers generally to a pathway wherein there is a closed loop with no waste outlet or perforation of the blanket with all air returned via a separate duct to the blower.

(19) Measurements have shown that a surgical patient under an aesthesia loses about 1.6 degrees C. body temperature during the first hour. Such body temperature loss can lead to hypothermia, shivering and may compromise the patient's healing ability. [See http://solutions.3m.com/wps/portal/3M/en_EU/Healthcare-Europe/EU-Home/Products/InfectionPrevention/Patient_Warming/.] Patient warming beds and warming blankets are essential to prevent this onset of patient hypothermia.

(20) For the past two decades, maintenance of patient body temperature during surgery has largely been achieved with forced hot air warming; this process replaced circulating hot water blankets, which were cumbersome and often ruptured, covering the floor with water. Tent, blanket and mattress designs have also been used. Virtually all of these have been inexpensive and disposable, and have attempted to avoid the problem of difficult and often incomplete cleaning between uses. All of the currently used forced hot air devices have a blanket or pad with multiple holes that emit the warmed air around the patient or an open tent over the patient into which the warm air is blown. Some recent studies have documented that the release or leakage of the forced air causes unwanted air currents that bring up potentially unclean air from near the floor or cause increased numbers of particles and bacteria to circulate over the prepped area of the surgical incision, increasing the risk of operative infection. Examination has also revealed bacteria collecting within the blowers. Another study demonstrated that the air currents interfere with the laminar airflow sometimes used in the operating room to discourage bacterial contamination. The FDA has also recently released an alert, describing their concerns and the need for a regular program of cleaning and maintenance of heater/cooler devices. While the contention that these devices are related to an increase in operative infections has been questioned, it seems reasonable to attempt to avoid air leakage and any possibly undesirable air currents that might increase infection risk. Avoiding the buildup of bacteria within the blower is obviously a reasonable goal. Bacterial contamination related to increased infection has recently been reported in the liquid of water blankets. Staying with a forced hot air system that employs inexpensive, disposable mattresses and blankets that do not need to be cleaned is clearly desirable.

(21) Recently FDC has issued the following warning located at http://www.medscape.com/viewarticle/852750 which is reproduced below:

(22) FDA Warns Infections a Risk With Heater-Cooler Devices Megan Brooks Disclosures|Oct. 15, 2015

(23) The use of heater-cooler devices has been associated with nontuberculous mycobacterium (NTM) infections, primarily in patients undergoing cardiothoracic surgeries, the US Food and Drug Administration (FDA) warned today.

(24) Heater-cooler devices are used during medical and surgical procedures to warm or cool a patient, as appropriate. The devices include water tanks that provide temperature-controlled water to external heat exchangers or warming/cooling blankets through closed circuits.

(25) Although the water in the circuits does not come into direct contact with the patient, there is the potential for contaminated water to enter other parts of the device or transmit bacteria through the air, via the device's exhaust vent, into the environment and to the patient, the FDA notes in a safety communication posted on its website. Between January 2010 and August 2015, the FDA received 32 reports of patient infections associated with heater-cooler devices or bacterial heater-cooler device contamination, with 25 reported this year.

(26) Some reports describe NTM infections related to cardiothoracic surgeries, but other reports do not specify the procedure the patient was undergoing, the FDA notes. Eight reports were related to three events describing patient infections occurring in US healthcare facilities, whereas the other 24 reports involved facilities outside the United States, mostly in Western Europe.

(27) In some cases, patients presented with infections several months to years after their surgical procedure. The FDA is not aware of NTM infections acquired by hospital staff.

(28) The FDA says it is actively monitoring the situation and will provide updates as appropriate.

(29) The aim of today's safety communication is to heighten awareness about infections associated with heater-cooler devices and steps health care providers and health facilities can take to mitigate risks to patients, they say.

(30) Recommendations

(31) In addition to following standard precautions, the FDA recommend that healthcare facilities and staff using heater-cooler devices consider implementing the following measures to reduce risk to patients:

(32) Strictly adhere to the cleaning and disinfection instructions provided in the manufacturer's device labeling. Ensure you have the most current version of the manufacturers' instructions for use readily available to promote adherence.

(33) Do not use tap water to rinse, fill, refill or top-off water tanks, as this may introduce NTM organisms. Use only sterile water or water that has been passed through a filter of less than or equal to 0.22 microns. When making ice needed for patient cooling during surgical procedures, use only sterile water or water that has been passed through a filter of less than or equal to 0.22 microns. Deionized water and sterile water created through reverse osmosis is not recommended because it may promote corrosion of the metal components of the system.

(34) Direct the heater-cooler's vent exhaust away from the surgical field to mitigate the risk of aerosolizing heater-cooler tank water into the sterile field and exposing the patient.

(35) Establish regular cleaning, disinfection, and maintenance schedules for heater-cooler devices according to the manufacturers' instructions to minimize the risk for bacterial growth and subsequent patient infection.

(36) Develop and follow a comprehensive quality control program for maintenance, cleaning, and disinfection of heater-cooler devices. Your program may include written procedures for monitoring adherence to the program and documenting set up, cleaning, and disinfection processes before and after use.

(37) Immediately remove from service heater-cooler devices that show discoloration or cloudiness in the fluid lines/circuits, which may indicate bacterial growth. Consult your hospital infection control officials to perform the appropriate follow-up measures and report events of device contamination to the manufacturer.

(38) Consider performing environmental, air, and water sampling and monitoring if heater-cooler contamination is suspected. Environmental monitoring requires specialized expertise and equipment to collect and process samples, which may not be feasible in all facilities.

(39) Healthcare facilities should follow their internal procedures for notifying and culturing patients if they suspect infection associated with heater-cooler devices.

(40) The present invention addresses the aforementioned issues by providing an antimicrobial mist generator operable as a stand-alone internal sterilizer for closed and non-closed-circuit blowers. Internal sterilization of the blower through use of the antimicrobial mist generator mitigates infection risks caused from contaminated air flow of the patient blower when it is being used with patient lifters and/or warmer devices. An outflow chamber/output duct of the antimicrobial mist generator is attached to a flexible hose that connects to an air inflow of any non-closed circuit device, temporarily making it run as a closed circuit and allowing internal sterilization, including drying, without releasing disinfectant vapor into the hospital environment. The antimicrobial mist generator, presumably, but not necessarily disposable, achieves the internal sterilization that is currently impossible with the patient heating devices now in use.

(41) When the antimicrobial mist generator is in-line with a patient warming device circulating heated controlled warm air, the warm air passes through the antimicrobial mist generator and become substantially saturated by evaporated disinfectant forming an aerated mist. As warm air carrying sterilizing mist passes through the non-closed circuit patient warmer device the disinfectant kills harmful bacteria and germs so that the non-closed circuit patient warmer device's internal chambers are substantially free of bacteria and germs, thereby decreasing infection risks. Non-closed circuit patient warmer devices include, for non-limiting example, sterilized blowers with microprocessor controlled air heating capabilities.

(42) The disinfectant utilized has a high volatility so that it is capable of evaporating and forming a saturated misted air flow up on application of the warm air pressure, yet substantially evaporating and dissipating to internally sterilize the non-closed circuit patient warmer device. The warming system circulates all of the warmed air within a non-closed circuit to provide internal sterilization, so that sterilized warmed air is released outside the non-closed warm air circulating system. Preferably, the disinfectant is a volatile liquid component that is adapted to vaporize as forced air blows over said disinfectant. Volatile liquid components preferably include alcohol-based solutions, containing one or more of isopropyl alcohol, ethanol (ethyl alcohol), and n-propanol solutions containing 60% to 95% alcohol. Non-alcohol based solutions may contain benzalkonium chloride or triclosan. Alternatively, the disinfectant may be a volatile liquid component saturated within a porous substrate, such as a sponge, capsule, cartridge or filter, and said liquid vaporizes and escapes the substrate as forced air blows over said substrate. The disinfectant may be in an aqueous solution with alcohol solution or antiseptic therein.

(43) The mist generator may include a transducer facilitating formation of the disinfectant mist, such as a piezoelectric transducer device including a transmitter, receiver or sensor, for converting high frequency electronic signals into high frequency mechanical vibration. The disinfectant (typically aqueous solution) cavitates into vapor which is forced through the surface of the disinfectant as a very fine mist, which is easily absorbed into the air flow. See for example http://www.piezo-ultrasonic.com/piezoelectric-transducer-applications-a006.html.

(44) The closed circuit of the warming system is sterilized with antimicrobial disinfectant spray or atomized mist. The warm air contained in the closed circulating system is sterile. At the end of use of the bed or blanket, the system can be sterilized with antimicrobial disinfectant atomized mist if desired and the disposable bed or blanket discarded.

(45) The closed circuit forced hot air warmer consists of a blower connected by flexible conduit using quick connect couplings to a terminal device, which may be a blanket or a mattress that is not an open tent. The air that enters the terminal device passes through a HEPA filter with a pore size less than 0.22 microns to catch any bacteria or particles in the incoming airflow. The warm air passes through a structured chamber, or a folded tube within the chamber, so that the blanket or mattress is filled with warm air that passes slowly through the device to an outflow port and returns back to the blower in a completely closed system. There are no apertures to release warm air and no air leaks from the system, avoiding possible turbulence and air currents in the operating room. The internal chamber structure insures that warm air is not shunted to the outflow port, but rather fills the entire chamber, so that the entire device remains warm, transmitting heat to the patient by direct contact and maintaining body temperature. The return air conduit is detachable from the device, as well. The blanket or mattress, therefore, remains a simple, inexpensive device and is suitable for disposal after use.

(46) The HEPA filters at the inflow and outflow portals of the blower and the fact that each disposable pad is clean help to avoid bacterial contamination. The unique design of the system makes sterilization of the air channels in the blower and the connecting tubes easy to perform. The detached ends of the flexible inflow and outflow lines are each connected to a small (detachable) chamber. A measured amount of liquid disinfectant is introduced through a separate port and the blower is turned on. The circulating air will take up the disinfectant, which will be carried through the system as an aerosol. After a brief period, all internal surfaces are disinfected. A second aliquot of STERILE distilled water can be added later to rinse out the system. Following the two steps, a desiccant, paper or sponge is introduced and the blower again turned on. Any residual liquid is caught in the dry material. The two conduits are then disconnected, the chamber discarded or emptied and the sterilized system is ready for use.

(47) A filtered port allows ambient air to enter the blower at the beginning of a cycle. When the system has been filled and air begins to return via the outflow conduit, the entry portal closes automatically or is capped and only air from the outflow conduit can enter the blower for recirculation.

(48) FIG. 1 illustrates at 100 a system for delivering warm air to patient beds and blankets in a closed circulating circuit. The closed circuit warm air delivery system comprises a blower 101 with microprocessor controlled temperature, pressure and flow control that has input and output ports each guarded by HEPA filters. The blower output port is connected to the input port of patient bed or blanket 102 using by flexible tubing with quick release connectors 104. The output port of the patient bed or blanket is connected to the input port of the blower 101 using flexible tubing again with quick release connectors 104. The microprocessor control panel is shown at 105. The microprocessor controls the warm air temperature at 105a warm airflow rate at 105b and warm air pressure at 105c. The warm airflow path is therefore a continuous closed circuit with no warm air escape location. The airflow rate is proportional to the speed of rotation of the blower motor. The electrical current supplied to the heating elements controls the warm air temperature.

(49) FIG. 2 illustrates at 200 the blower with air warmer machinery and flexible tubes used being sterilized by the antimicrobial mist generator. The blower with air warmer machinery is shown at 101 with HEPA filters both at inlet and outlet. The output of the blower is connected to the inlet of the antimicrobial mist generator 103 using a flexible hose provided with quick release couplings. The output of the antimicrobial mist generator 103 is connected to the inlet port of the blower 101 using a flexible hose provided with quick release couplings. The antimicrobial solution in the antimicrobial mist generator is atomized and circulated in this closed path for a preselected time period, which may be as long as 15 minutes, disinfecting circuit sterilizing the blower with air warming machinery 101 and all the flexible hoses in the system. At the end of this disinfecting step, the quick release couplings are disconnected and reattached to the blower and the mat. Any moisture present in the blower 101 and flexible hoses can be blown into a dry sponge.

(50) FIG. 3 illustrates at 300 the details of the microprocessor controlled blower with warm air delivery 101. As illustrated, the blower has input port 302 and output port 303 both provided with HEPA filters. The quick release connectors of the flexible hose are shown at 104. The warm air flow bath is indicated by the arrows. The blower with warm air delivery has a blower fan and electrical heating elements with sensors for air temperature, air pressure and air low rate communicating with the microprocessor control as shown in FIG. 1.

(51) FIG. 4 illustrates at 400 an embodiment of the antimicrobial mist generator, which is only used to achieve internal sterilization of the blower warm air machinery 101 and all the flexible hoses used. The mist generator is filled with a capsule 402 that has the antimicrobial liquid sealed with gasket 403, which is atomized by the flow of warm air through the input port and is delivered to the output port. In an alternative embodiment a microprocessor may be provided which preferably turns on the antimicrobial mist spray during initial set up to sterilize the interior surfaces of blower and flexible tubes. When the sterilization operation is complete, an aliquot of sterile distilled water is introduced and any residual disinfectant is vaporized in the circulated water vapor. Any remaining water can be taken up into a clean sponge or desiccant. Quick release couplings 104 connect the flexible hoses to the inlet and outlet of antimicrobial mist generator 103. The mist generator is then disconnected from both flexible hoses and discarded.

(52) FIG. 5 illustrates at 500 the patient bed or blanket 102 for a closed system. The inlet of warm air into the bed or blanket is shown at 501. The patient bed or blanket has a plurality of interconnected airflow paths indicated by arrows shown at 503. The outlet of the patient bed or blanket 102 is shown at 502. The connection of flexible hose to the inlet and outlet is done using quick release couplings 104.

(53) FIG. 6 illustrates at 600 an optional arrangement for the sterilization process of patient bed or blanket. This is similar to FIG. 1 except that the antimicrobial mist generator 103 is inserted between the blower warm air machinery 101 and the patient bed or blanket 102 and a closed circuit is formed using flexible hoses with quick release connectors 104. When used prior to disposal, the sterilization process can be run for about 15 minutes and the sterilized patient bed or blanket is then discarded.

(54) FIG. 7 illustrates another embodiment of the microprocessor controlled antimicrobial mist generator, shown generally at 700. FIG. 8 illustrates the embodiment of FIG. 7 in-line with a non-closed circuit blower, shown generally at 800, forming a temporarily closed circuit.

(55) Referring to FIGS. 7 and 8, the antimicrobial mist generator 703 is only used to achieve internal sterilization of the blower warm air machinery and all the flexible hoses associated therewith. The mist generator comprises a main body 701 having a top wall 730 with an opening 730 with a removable cap, the opening traversing into a chamber 702 adapted to receive a disinfectant shown generally at 702 (misting shown in FIG. 8 at 702), side walls 703 and a bottom wall 704 that may include a bottom cover to allow access into the chamber of the main body for inserting and later removing desiccant and the like. The main body 701 further includes an inlet duct 705 adapted for attachment to a first hose 706 which in turn is adapted for attachment to an output opening 711 of a blower 710 for delivery of forced air into the chamber 702 to carry disinfectant misted air. The main body 701 also includes an output duct 707 adapted for attachment to a second hose 708 which in turn is adapted for attachment to a blower inlet 712 opening of the blower 710 for delivery of disinfectant misted air through internal components of the blower 710 to improve sterility of the blower 710 to mitigate microbial contamination of patient warmers and lifters and hospital environments when the blower is in use. Second hose 708 is attached to the blower inlet 712 by way of an attachment or modification to the inflow of the blower to accept that hose, shown generally at 708. The blower with air warmer machinery is shown at 710 with HEPA filters at each inlet 712 and outlet 711.

(56) The top wall opening 730 is preferably includes a narrow (5 cm) neck closed with a removable cap so that disinfectant, water, dry desiccant, etc., can be introduced through the neck/opening 730. Owing to the narrow neck and opening 730, desiccant and other bulky solids cannot be easily removed, and therefore re-use is avoided. However, if the mist generator is not disposable, the bottom wall may include a bottom cap/base that is removable by screwing same off to permit emptying of the mist generator.

(57) Capsule or chamber 702 has the antimicrobial or disinfectant liquid sealed with a gasket/diaphragm preferably at opening 730. The liquid is atomized by the flow of warm air through the input port and is delivered to the output port. In an alternative embodiment, a transducer for misting the liquid may be provided. The antimicrobial mist generator may be microprocessor controlled wherein the controls turn on an antimicrobial mist spray during initial set up to sterilize the interior surfaces of blower air machinery and flexible tubes attached thereto. When the sterilization operation is complete, an aliquot of sterile distilled water is introduced and any residual disinfectant is vaporized in the circulated water vapor. Any remaining water can be taken up into a clean sponge or desiccant. Quick release couplings 104 connect the flexible hoses to the inlet and outlet of antimicrobial mist generator 103. The mist generator is then disconnected from both flexible hoses and discarded.

(58) The antimicrobial mist generator is capable of being utilized as a stand-alone internal sterilizer for non-closed-circuit patient warmers. Antimicrobial mist generator includes a mist chamber for housing a disinfectant adapted to vaporize or form a mist upon contact with warm air. Preferably the outflow/outlet of the chamber is attached to flexible hose 704 connected to any non-closed circuit device, temporarily making it run as a closed circuit and allowing internal sterilization, including drying, without releasing disinfectant vapor into the hospital environment. The generator, presumably, but not necessarily disposable, would achieve the internal sterilization that is currently impossible with the blower devices now in use.

(59) Flexible hoses (fixed or detached) are attached to the mist generator via the inflow part of a warmer that is not closed circuit, creating a temporary closed circuit that allows internal sterilization. An aliquot of sterile water can be introduced after the sterilization takes place to remove residual disinfectant. A sponge or descant is inserted and the system again run to remove residual liquid/vapor.

(60) FDA required regular cleaning of patient heating devices can be achieved with the subject system without changing any other components. Heated air takes up the fluid within the chamber whereupon it continues traveling with the warm forced air as a mist or vapor through tubes to sterilize devices attached thereto. Fluids contemplated include chemicals compositions having relatively low boiling points or volatility so that the disinfectant vaporizes upon being heated by way of the warm air. Examples include alcohols such as ethanol etc.

(61) FIG. 9a illustrates another embodiment of the antimicrobial mist generator, shown generally at 900. The antimicrobial mist generator 903 is generally used to achieve internal sterilization of the blower warm air machinery and all the flexible hoses used. The mist generator is filled with a capsule 902 that has the antimicrobial liquid sealed with gasket/diaphragm 905, which is atomized by the flow of warm air through the input port and is delivered to the output port. The antimicrobial mist generator 903 turns on the antimicrobial mist spray during initial set up to sterilize the interior surfaces of blower air machinery and flexible tubes attached thereto. When the sterilization operation is complete, an aliquot of sterile distilled water may be introduced and any residual disinfectant is removed in the circulated water vapor. Quick release couplings 904 connect the flexible hose to the inlet of antimicrobial mist generator 903. Antimicrobial mist generator 903 preferably includes an outlet 903 whereupon either a cap 906 or a quick release coupling 904 connecting to a flexible hose is preferably provided for connection of the mist generator 903 to patient warmer devices including for example blower warm air machinery (see FIGS. 2 and 10), or a mattress or a bed for sterilization thereof (see FIG. 6). The mist generator is disconnected from both flexible hoses after the system is dried internally by running the blower, and excess water is taken up into a clean sponge or desiccant.

(62) The antimicrobial mist generator 903 is capable of being utilized as a stand-alone internal sterilizer for non-closed-circuit patient warmers (such as without limitation the kind use by 3M associated with the trade name BAIR and others). Antimicrobial mist generator 903 includes a mist chamber 910 for housing a disinfectant adapted to vaporize or form a mist upon contact with warm air. In this use, the outflow/outlet 903 of the chamber 910 is attached to flexible hose 904 connected to a non-closed circuit device, temporarily making it run as a closed circuit and allowing internal sterilization, including drying, without releasing disinfectant vapor into the hospital environment (See FIG. 10). The generator, presumably, but not necessarily disposable, would achieve the internal sterilization that is currently impossible with the patient heating devices now in use. Preferably the mist generator 903 is shaped having a neck portion 921 at the top with a diameter substantially less than the diameter of a bottom portion 922. Preferably, neck portion 921 has a diameter of approximately 5 cm, which is substantially less than the diameter of a bottom portion 922 which in turn preferably includes curved walls so that the bottom portion is substantially bulbous. The bottom portion 922 may include a bottom opening with a removable bottom cover 923 that affords access to the chamber of the mist generator to allow addition and later removal of desiccant or fibers that can absorb circulating moisture, the cover 923 being necessary only if the mist generator is designed and employed for multiple use. The preferred embodiment is for the bottom portion to be solid, making it difficult to remove the solid desiccant that was easily introduced through the narrow neck of the upper portion 921, encouraging single use and disposal of the used mist generator, thus avoiding release of contaminated material and disinfectant into the hospital environment.

(63) Flexible hoses (fixed or detached) from the outlet flow port of the mist generator to the inflow port of a blower that is non-closed circuit, creating a temporary closed circuit that allows internal sterilization. An aliquot of sterile water can be introduced after the sterilization takes place to remove residual disinfectant, and then removed by uptake into a sponge or descant.

(64) FDA recommended regular cleaning of patient heating devices which can be achieved with the subject system without changing any other components. Preferably to avoid a port into the chamber 910 that could be opened for filling, a soft diaphragm 905 is provided through which fluids can be introduced with a needle and syringe (similar to medicine vials). The disinfecting liquid may be contained in a sealed prefilled capsale, which is perforated when pushed into the chamber 910, releasing the enclosed fluid. The heated air causes the fluid of capsule 902 to atomize within chamber 910, whereupon it continues traveling with the warm forced air as a mist or vapor through tubes to sterilize devices attached thereto. Fluids contemplated include chemicals compositions having relatively low boiling points or volatility so that the disinfectant vaporizes upon being heated by way of the warm air. Examples include alcohols such as ethanol etc. Embodiments of the capsule/cartridge are shown in FIGS. 9b-9d.

(65) FIG. 9b illustrates another embodiment of a capsule/cartridge 950 adapted to be inserted within the mist generator of FIG. 9a. Capsule/cartridge 950 is a spray cartridge containing a liquid disinfectant/antimicrobial solution generally constructed as a spray bottle construction, including a reservoir 951 housing the liquid having a tube 952 therein. A cartridge pump 953 is provided with a trigger mechanism, a piston, a cylinder and a one-way valve in-line with a spray nozzle 954. Spray nozzle 954 includes a one-way valve to prevent air from flowing back into the pump and allowing suction within the pump so that liquid is pulled through tube 952. Nozzle 954 concentrates the liquid into a stream forcing it through a small hole. When the trigger is pressed, it forces the piston into the cylinder, which forces the liquid through the nozzle as a concentrated stream of liquid. When the trigger is released, the piston moves back, pulling liquid back into the cylinder. This liquid is forced out of the nozzle the next time the trigger is pressed. A one-way valve at the bottom of the pump only allows liquid to flow up the tube into the pump, not back into the bottle. The mist generator preferably includes a spray activator herein shown as a bracket 955 that the capsule/cartridge 950 sits within when it is inserted in the chamber of the mist generator. Bracket 955 may be provided so that it is in-line with a manual button that when depressed presses the capsule/cartridge 950 downward and causes the trigger of the pump to be activated to release spray. Preferably, bracket 955 is in-line with an electronic switch that activates the trigger to cause release of the spray.

(66) FIG. 9c illustrates an embodiment of a capsule/cartridge 960 adapted to be inserted within the mist generator of FIG. 9a. In this embodiment, capsule/cartridge 960 includes a reservoir 961 holding a volatile disinfectant liquid and side walls 962 having at least a portion therein that include small apertures or perforations 963 for release of misted liquid as air passes through the chamber of the mist generator. It is noted that the reservoir 961 may hold a volatile disinfectant liquid, or a semi solid or membrane holding the liquid that releases the liquid as forced heated air passes through the chamber of the mist generator.

(67) A separate capsule/cartridge may be provided housing a fiber or desiccant when the mist generator is in a drying mode such as after the disinfectant procedure is complete. The user simply places a capsule/cartridge housing the disinfectant into the chamber of the mist generator and runs a disinfectant operation for a period of time as shown in FIG. 10. When the disinfectant run is complete, the user can simply remove the capsule/cartridge and replace it with a drying capsule/cartridge that contains fiber or desiccant and performs a drying run for a period of time to dry liquid/residual mist from the generator, tubes and blower. Upon completion, the capsules/cartridges, as well as the mist generator itself, are preferably discarded.

(68) FIG. 9d illustrates another embodiment of a capsule/cartridge 970 adapted to be inserted within the mist generator of FIG. 9a. In this embodiment, the reservoir 971 housing the disinfectant is located within a capsule chamber 972. At least a portion of side walls 973 of the reservoir has apertures or holes therein for the escape of misted disinfectant as air passes through the chamber of the mist generator.

(69) FIG. 10 illustrates at 1000 another embodiment of the blower with air warmer machinery and flexible tubes being sterilized by the antimicrobial mist generator. The blower with air warmer machinery is shown at 1001 with HEPA filters both at inlet and outlet 1001 and 1001. The output 1001 of the blower 1001 is connected to the inlet of the antimicrobial mist generator 1003 using a flexible hose provided with quick release couplings. The output of the antimicrobial mist generator 1003 is connected to the inlet port 1001 of the blower 1001 using a flexible hose provided with quick release couplings temporarily forming a closed circuit system. The antimicrobial solution in the antimicrobial mist generator is atomized and circulated in this closed path for a preselected time period, which may be as long as 15 minutes, disinfecting circuit sterilizing the blower with air warming machinery 1001 and all the flexible hoses in the system. At the end of this disinfecting step, any moisture present in the blower 1001 and flexible hoses is taken up into a dry sponge. The quick release couplings are then disconnected.

(70) The microprocessor control panel is shown at 1005. The microprocessor controls the warm air temperature at 1005a warm airflow rate at 1005b and warm air pressure at 1005c. The warm airflow path is therefore a continuous closed circuit with no warm air escape location. The airflow rate is proportional to the speed of rotation of the blower motor. The electrical current supplied to the heating elements controls the warm air temperature.

(71) FIG. 11 illustrates another embodiment of the subject mist generator, shown generally at 1100. The mist generator comprises a main body 1101 having a top wall 1111 with an opening 1111, the opening traversing into a chamber 1102 adapted to receive a disinfectant shown generally at 1102, side walls 1103 and a bottom wall 1104. The main body 1101 further includes an inlet duct 1105 adapted for attachment to a first hose which in turn is adapted for attachment to an output opening of a blower for delivery of forced air into the chamber 1102 to create misted disinfectant in the air. The main body 1101 also includes an output duct 1107 adapted for attachment to a second hose which in turn is adapted for attachment to a blower inlet opening of the blower for delivery of disinfectant misted air through internal components of the blower. In the embodiment shown, the bottom wall 1104 includes a bottom opening with a removable bottom cover 1131, which can cause removal of the main body 1101 from bottom cover 1131 for insertion of desiccant, and/or paper towels, etc. In the embodiment shown, cover 1131 also includes an optional transducer 1150 for vibration misting the liquid within the chamber.

(72) Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to, but that additional changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.