Gas sterilization/disinfection system and method for fluid conduits

The present disclosure pertains to a ventilator treatment system configured to sterilize and/or disinfect a fluid pathway through a ventilator by providing a forced flow of treatment gas to the ventilator. Ventilators are frequently contaminated with bacteria and viruses during normal use. When a ventilator is moved from one patient to the next, there is a risk of contaminating the new patient with a pathogen from the previous patient. The application of treatment gas is especially practical for sanitizing hard to access surfaces such as those found in the cavities and conduits (the fluid pathway) of a ventilator. A treatment gas such as, for example, ozone, converts back to oxygen and has a short half life, which can be further reduced with humidity, heat, or inexpensive destruct catalysts. This disclosure is applicable to any medical device with a fluid pathway that can become contaminated, provided the materials in the fluid pathway of the medical device are compatible with the sterilization and/or disinfection gas. In one embodiment, the ventilator sterilization system comprises one or more of a treatment gas flow generator, a gas circuit, a user interface, one or more sensors, a treatment gas remediation system, an exhaust port, one or more valves, a processor, electronic storage, and/or other components.

BACKGROUND

The present disclosure pertains to a method and apparatus for sterilizing and/or disinfecting the fluid pathway of a ventilator using a treatment gas.

2. Description of the Related Art

It is well known to disinfect contaminated surfaces to avoid microbial cross-contamination. The application of liquid disinfecting agents is effective for accessible, chemical resistant surfaces as well as cavities on objects that can be submersed. But submersion in liquid chemical germicides and disinfectants is not suitable for many delicate instruments (e.g., instruments with electrical circuitry). Steam is often used for disinfection and sterilization, especially in medical facilities, but repeated exposure to heat and moisture can be damaging to many materials and electronic components. Exposure to gamma or E-beam radiation requires equipment and a facility with the appropriate safety precautions. UV light radiation requires a direct UV light path to all contaminated surfaces.

Filters are often used on ventilators to reduce the risk of contamination when the ventilator is moved from one patient to the next. However, filters are not always used, are not always effective against all biological contaminants, and are sometimes faulty. A patient may still be exposed to contaminants in the ventilator's fluid pathway.

Gas sterilizers on the market today are high cost, require inconvenient handling/storing of the gas or liquid sterilant, require the need for long out-gassing periods, require precautions for the hazards associated with exposure, and/or require the contaminated object to be placed within a gas sterilization chamber.

Marketed gas sterilization chamber systems require a great deal of dedicated space within a facility and require the entire medical device be placed in the sterilization chamber and exposed to sterilization gas. In the case of a ventilator, only the gas path needs to be disinfected or sterilized, not the sensitive electronics that are also part of the ventilating device.

SUMMARY

Accordingly, one or more aspects of the present disclosure relate to a ventilator treatment system configured to provide a flow of treatment gas through a ventilator to at least disinfect a fluid pathway through the ventilator. In some embodiments, the system comprises a treatment gas (e.g., ozone) flow generator, a gas circuit, a first interface, and a second interface. The treatment gas flow generator is configured to generate a forced flow of treatment gas for delivery to the fluid pathway of the ventilator. The gas circuit is configured to conduct the forced flow of treatment gas from the treatment gas flow generator to the ventilator. The gas circuit comprises a first interface configured to form a releasable sealed interface with a ventilator fluid pathway inlet of the ventilator such that the forced flow of treatment gas is directed into the fluid pathway of the ventilator through the first interface. The gas circuit comprises a second interface configured to form a releasable sealed interface with a ventilator fluid pathway outlet of the ventilator such that the forced flow of treatment gas is received back into the gas circuit from the fluid pathway of the ventilator through the second interface.

Yet another aspect of the present disclosure relates to a method of providing a flow of treatment gas through a ventilator to at least disinfect a fluid pathway through the ventilator. In some embodiments, the method comprises generating a forced flow of treatment gas for delivery to the fluid pathway of the ventilator; conducting the forced flow of treatment gas to the ventilator via a gas circuit; interfacing a ventilator fluid pathway inlet such that the forced flow of treatment gas directed into the fluid pathway of the ventilator; and interfacing a ventilator fluid pathway outlet such that the forced flow of treatment gas is received back into the gas circuit from the fluid pathway of the ventilator.

Still another aspect of present disclosure relates to a ventilator treatment system configured to provide a flow of treatment gas through a ventilator to at least disinfect a fluid pathway through the ventilator. In some embodiments, the system comprises means to generate a forced flow of treatment gas for delivery to the fluid pathway of the ventilator; and means to conduct the forced flow of treatment gas from the treatment gas flow generator to the ventilator. In some embodiments the means to conduct the forced flow of treatment gas comprises means to form a releasable sealed interface with a ventilator fluid pathway inlet of the ventilator such that the forced flow of treatment gas is directed into the fluid pathway of the ventilator through the inlet interfacing means; and means to form a releasable sealed interface with a ventilator fluid pathway outlet of the ventilator such that the forced flow of treatment gas is received back into the gas circuit from the fluid pathway of the ventilator through the outlet interfacing means.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1schematically illustrates an exemplary embodiment of a ventilator sterilization/disinfection system10. Ventilator sterilization/disinfection system10is configured to sterilize/disinfect a fluid pathway through the ventilator by providing a forced flow of treatment gas to the ventilator. The treatment gas may comprise a sterilization gas, a disinfection gas, and/or other gases. Disinfection gas may comprise a gas configured to eliminate and/or reduce harmful microorganisms in the ventilator. Sterilization gas may comprise a gas configured to eliminate and/or reduce more microorganisms in the ventilator compared to disinfection gas.

Ventilators are frequently contaminated with bacteria and viruses during normal use. When a ventilator is moved from one patient to the next, there is a risk of contaminating the new patient with a pathogen from the previous patient. The application of a treatment gas is especially practical for sanitizing hard to access surfaces such as those found in the cavities and conduits (the fluid pathway) of a ventilator. A treatment gas such as, for example, ozone, converts back to oxygen and has a short half life, which can be further reduced with humidity, heat, or inexpensive destruct catalysts.

This disclosure is applicable to any medical device with a fluid pathway that can become contaminated, provided the materials in the fluid pathway of the medical device are compatible with the treatment gas. Such medical devices include ventilators. In one embodiment, system10comprises one or more of a treatment gas flow generator12, a gas circuit14, a user interface16, one or more sensors18, a treatment gas remediation system20, an exhaust port22, one or more valves24, a processor26, electronic storage28, and/or other components.

By way of a non limiting example, system10inFIG. 1operates to circulate gas from treatment gas flow generator12to a ventilator30through gas circuit14. The treatment gas may continue to flow through one or more valves24and back through treatment gas flow generator12and/or ventilator30, completing a cycle. The treatment gas continues this cycle until the desired, for example, treatment gas concentration and/or duration needed for sterilization/disinfection is achieved. Processor26may be configured to control treatment gas flow generator12to adjust one or more of the duration, concentration, and/or other parameters. In some embodiments, processor26controls treatment gas flow generator12to deactivate treatment gas generation once a desired concentration, for example, has been achieved. With treatment gas generation deactivated, existing treatment gas may continue to be circulated by treatment gas flow generator12for a duration necessary to ensure adequate sterilization/disinfection. Once sterilization/disinfection is achieved, one or more valves24may direct the gas flow through treatment gas remediation system20and/or out exhaust port22.

In some embodiments, treatment gas flow generator12is configured to generate a forced flow of treatment gas for delivery to the fluid pathway of a ventilator30. Treatment gas flow generator12may be configured to generate a flow of sterilization gas, disinfection gas, and/or other gases. Treatment gas flow generator12may be configured for one or more of treatment gas generation, gas pressurization, gas humidification and/or drying, gas heating and/or cooling, and/or other functions. The functions of treatment gas flow generator12may operate individually and/or in coordination. For example, in some embodiments, treatment gas flow generator12may be configured to conduct existing gas through the gas circuit while no new treatment gas is generated. In some embodiments, treatment gas flow generator12may be integrated with ventilator30in a single device.

Treatment gas flow generator12may be configured to generate treatment gas by changing the composition of the pressurized gas within treatment gas flow generator12. Treatment gas flow generator12may be configured to generate treatment gas from one or more source gases comprising one or more of oxygen, ambient air, and/or other source gases. In some embodiments, ambient air may be drawn into treatment gas flow generator12via an inlet in treatment gas flow generator12. One or more methods used by treatment gas flow generator12to generate the treatment gas from a source gas may comprise one or more of UV radiation, corona discharge, cold plasma, and/or other treatment gas generation methods. In some embodiments treatment gas flow generator12may be configured to connect to an external source of treatment gas and import treatment gas into system10from the external source of treatment gas.

Humidity may be introduced to the gas in gas circuit14by treatment gas flow generator12. Humidity may be introduced to, for example, create hydroxyl molecules which aid in killing microorganisms. Conversely, the treatment gas may be dried by treatment gas flow generator12. The gas may be dried to, for example, avoid damage to ventilator component materials and/or electronics, and/or to increase sterile gas production, depending on the generation technique.

Treatment gas flow generator12may be configured to heat and/or cool the gas passing through treatment gas flow generator12. The gas may be heated, for example, to disassociate ozone into O2. The gas may be cooled, for example, to overcome heat production during the gas generation process and/or to maintain the sterilization/disinfection effectiveness of the sterile gas.

Treatment gas flow generator12may comprise an oscillator configured to improve treatment gas penetration into the fluid pathway of the ventilator, and/or for other purposes.

The forced flow of treatment gas is delivered to the fluid pathway of ventilator30via gas circuit14. Gas circuit14is configured to communicate the forced flow of treatment gas generated by treatment gas flow generator12to the fluid pathway of ventilator30. As such, gas circuit14comprises one or more conduits32, a ventilator fluid pathway inlet interface34, a ventilator fluid pathway outlet interface36, and/or other components. Conduits32are configured to convey the forced flow of treatment gas from treatment gas flow generator12to ventilator fluid pathway inlet interface34, and from fluid pathway outlet interface36back to treatment gas flow generator12. Ventilator fluid pathway inlet interface34is configured to form a releasable sealed interface with a ventilator fluid pathway inlet such that the forced flow of treatment gas is directed into the fluid pathway of ventilator30. Ventilator fluid pathway outlet interface36is configured to form a releasable sealed interface with a ventilator fluid pathway outlet of ventilator30such that the forced flow of treatment gas is received back into gas circuit14from the fluid pathway of ventilator30. In some embodiments, additional adapters and/or other coupling devices may be used to couple one or more ports on ventilator30to each other, to couple gas circuit14to ventilators of different makes and/or models, to couple gas circuit14to other various medical devices, and/or for other coupling and/or adaptation purposes.

For example,FIG. 2schematically illustrates coupling two ports on ventilator30to each other. In this example, an exhalation port40and an inspiratory port42are coupled via inspiratory/exhalation interface44, creating a gas pathway between the two ports.

Returning toFIG. 1, user interface16is configured to provide an interface between system10and a user through which the user may provide information to and receive information from system10. This enables data, results, and/or instructions and any other communicable items, collectively referred to as “information,” to be communicated between the user and one or more of treatment gas flow generator12, processor26, electronic storage28, and/or other components of system10. Examples of information communicated through user interface16may comprise one or more of treatment gas concentration, flow, volume, pressure, temperature, and/or other parameters. Examples of interface devices suitable for inclusion in user interface16include a, a keypad, buttons, switches, a keyboard, knobs, levers, a display screen, a touch screen, speakers, a microphone, an indicator light, an audible alarm, a printer, and/or other interface devices. In one embodiment, user interface16includes a plurality of separate interfaces. In one embodiment, user interface16includes at least one interface that is provided integrally with treatment gas flow generator12.

It is to be understood that other communication techniques, either hard-wired or wireless, are also contemplated by the present disclosure as user interface16. Other exemplary input devices and techniques adapted for use with system10as user interface16include, but are not limited to, an RS-232 port, RF link, an IR link, modem (telephone, cable or other). In short, any technique for communicating information with system10is contemplated by the present disclosure as user interface16.

In one embodiment, user interface16is configured to display previous information entered by a user, information generated by processor26, information stored in electronic storage28, and/or other information to a user. For example, user interface16may display treatment time for the current sterilization/disinfection run and/or average treatment time for multiple previous sterilization/disinfection runs.

One or more sensors18are configured to generate one or more output signals conveying information related to one or more parameters of the forced flow of gas. The one or more parameters may include, for example, one or more of a flow rate, a volume, a pressure, a composition (e.g., concentration(s) of one or more constituents), humidity, temperature, acceleration, velocity, and/or other gas parameters. Sensors18may include one or more sensors that measure such parameters directly (e.g., through fluid communication with the forced flow of treatment gas at treatment gas flow generator12or at ventilator fluid pathway interfaces34and/or36). The sensors18may comprise one or more sensors that generate output signals related to one or more parameters of the forced flow of gas indirectly. For example, one or more of sensors18may generate an output based on an operating parameter of treatment gas flow generator12(e.g., a motor current, voltage, rotational velocity, and/or other operating parameters), and/or other sensors. Although sensors18are illustrated at a single location between ventilator30and treatment gas flow generator12, this is not intended to be limiting. Sensors18may include sensors disposed in a plurality of locations, such as for example, at various locations within (or in communication with) conduits32, within treatment gas flow generator12, within treatment gas remediation system20, within valves24, within exhaust port22, and/or other locations.

Treatment gas remediation system20is configured to remediate the forced flow of treatment gas downstream from ventilator30. Treatment gas remediation system20may comprise a gas destruct catalyst, a heat source, and/or other components configured to eliminate treatment gas from system10. In some embodiments, treatment gas may pass through the treatment gas remediation system before exiting system10through exhaust port22. Exhaust port22is configured to open gas circuit14to ambient air.

One or more valves24are configured to selectively guide the treatment gas between one or more of treatment gas flow generator12, ventilator30, treatment gas remediation system20, exhaust port22, and/or other components. In some embodiments, valves24may be configured to guide treatment gas from treatment gas flow generator12, through ventilator30, and back to treatment gas flow generator12. In some embodiments, valves24may be configured to guide recirculation of the treatment gas through the treatment gas flow generator to build and maintain a desired treatment gas concentration, for example. In some embodiments, valves24may be configured to guide recirculation of treatment gas through ventilator30. In some embodiments, the one or more valves24may be configured to guide the treatment gas flow through one or more of the sterile gas destruct catalyst, the heat source, and/or out exhaust port22.

In one embodiment, valves24may comprise one or more valves in series and/or in parallel. Valves24may be located at one or more locations in system10. For example, in some embodiments valves24may be located in gas circuit14between ventilator fluid pathway outlet interface36and treatment gas remediation system20. As another example, in some embodiments, valves24may be located between treatment gas flow generator12and ventilator30. A non limiting example of a valve and/or other flow regulating device suitable for inclusion in valves24is a three-way valve. Valves24may be controlled hydraulically, pneumatically, via an electric motor and/or another mode of control.

Processor26is configured to provide information processing capabilities in system10. As such, processor26may include one or more of a digital processor, an analog processor, a digital circuit designed to process information, an analog circuit designed to process information, a state machine, and/or other mechanisms for electronically processing information. Although processor26is shown inFIG. 1as a single entity, this is for illustrative purposes only. In some implementations, processor26may include a plurality of processing units. These processing units may be physically located within the same device (e.g., treatment gas flow generator12), or processor26may represent processing functionality of a plurality of devices operating in coordination (e.g., a processor located within treatment gas flow generator12and a second processor located within user interface16).

As shown inFIG. 1, processor26is configured to execute one or more computer program modules. The one or more computer program modules may comprise one or more of a parameter module50, a sterilization timing module52, a control module54, and/or other modules. Processor20may be configured to execute modules50,52, and/or54by software; hardware; firmware; some combination of software, hardware, and/or firmware; and/or other mechanisms for configuring processing capabilities on processor26.

It should be appreciated that although modules50,52, and54are illustrated inFIG. 1as being co-located within a single processing unit, in implementations in which processor26includes multiple processing units, one or more of modules50,52, and/or54may be located remotely from the other modules. The description of the functionality provided by the different modules50,52, and/or54described below is for illustrative purposes, and is not intended to be limiting, as any of modules50,52, and/or54may provide more or less functionality than is described. For example, one or more of modules50,52, and/or54may be eliminated, and some or all of its functionality may be provided by other ones of modules50,52, and/or54. As another example, processor26may be configured to execute one or more additional modules that may perform some or all of the functionality attributed below to one of modules50,52, and/or54.

Parameter module50is configured to determine one or more gas parameters of the treatment gas. The one or more gas parameters are determined based on the one or more output signals generated by sensors18. The one or more gas parameters may include, for example, one or more of a flow rate, a volume, a pressure, a composition (e.g., concentration(s) of one or more constituents), humidity, temperature, acceleration, velocity, and/or other gas parameters. In some embodiments, gas parameter module50determines the one or more gas parameters dynamically based on treatment gas flow. By way of a non-limiting example, gas parameter module50may determine treatment gas concentration over time. In some embodiments, gas parameter module50determines one or more gas parameters at one or more locations around system10. By way of a non-limiting example, gas parameter module50may determine treatment gas concentration inside treatment gas flow generator12, at ventilator outlet interface36, at treatment gas remediation system20, and/or other locations.

Treatment timing module52is configured to determine a period of time during which treatment gas is directed through the fluid pathway of the ventilator. The time determination may be based user input, output signals generated by sensors18, output information from parameter module50, and/or other information. For example, a user may set a treatment time of 1 hour via user interface16. In some embodiments, treatment timing module52determines the treatment time dynamically based on one or more treatment gas flow parameters such as, for example, treatment gas concentration, pressure, flow rate, volume, humidity, temperature, and/or other parameters. For example, a lower concentration of treatment gas may necessitate a longer treatment time. A higher concentration of treatment gas may necessitate a shorter treatment time. In some embodiments, treatment timing module52may determine the treatment time based on one or more features of ventilator30such as, for example, geometry of the ventilator's fluid pathway (e.g., deadspace in the ventilator's fluid pathway, the size of the ventilator input/output orifices), the materials comprising the ventilator's fluid pathway, and/or other features of ventilator30.

Control module54is configured to control the one or more parameters of the forced flow of treatment gas. Control module54is configured to control the treatment gas flow path through gas circuit14. Control module54is configured to control the one or more parameters and/or the gas flow path based on one or more of user input, output signals generated by sensors18, output information from parameter module50, output information from treatment timing module52, and/or other information. By way of a non-limiting example, responsive to a determination by treatment timing module52that the treatment time has been met, control module54may be configured to cease treatment gas generation in treatment gas flow generator12but continue the flow of gas through treatment gas remediation system20. By way of another non-limiting example, control module54may control valves24to re-circulate the treatment gas through treatment gas flow generator12until a threshold treatment gas concentration is breached. In some embodiments, control module54may be configured to detect a leak in gas circuit14based on one or more of output signals generated by sensors18, output information from parameter module50, and/or other information, and cease operation of system10. For example, control module54may stop operation of system10for safety reasons because it detected a leak via pressure related information and/or flow related information from parameter module50.

In some embodiments, control module54is configured to compare the treatment gas parameter information to threshold values (e.g., a minimum treatment gas concentration necessary to achieve sterilization/disinfection, gas concentration versus time, etc.), and to control the one or more parameters of the forced flow of treatment gas to meet threshold requirements. In some embodiments, threshold values may comprise chemical and/or biological indicators of sterilization/disinfection. Gas parameter thresholds may be predetermined at manufacture, determined by programming threshold values into processor26, determined responsive to information entered by a user via user interface16, determined directly based the one or more output signals generated by sensors18, determined dynamically based on treatment gas flow, and/or determined by another method. For example, a treatment gas concentration threshold may comprise a minimum concentration entered by a user via user interface16. In some embodiments, treatment gas concentration, and/or application time may be adjusted to achieve different levels of disinfection and/or sterilization.

In some embodiments, electronic storage28comprises electronic storage media that electronically stores information. The electronic storage media of electronic storage28may include one or both of system storage that is provided integrally (i.e., substantially non-removable) with system10and/or removable storage that is removably connectable to system10via, for example, a port (e.g., a USB port, a firewire port, etc.) or a drive (e.g., a disk drive, etc.). Electronic storage28may include one or more of optically readable storage media (e.g., optical disks, etc.), magnetically readable storage media (e.g., magnetic tape, magnetic hard drive, floppy drive, etc.), electrical charge-based storage media (e.g., EEPROM, RAM, etc.), solid-state storage media (e.g., flash drive, etc.), and/or other electronically readable storage media. Electronic storage28may store software algorithms, information determined by processor26, information received via user interface16, and/or other information that enables system10to function properly. Electronic storage28may be (in whole or in part) a separate component within system10, or electronic storage28may be provided (in whole or in part) integrally with one or more other components of system10(e.g., user interface16, processor26, etc.).

The example system configuration described above (FIG. 1) is for illustrative purposes and is not intended to be limiting. Other exemplary embodiments of system10are shown inFIG. 3throughFIG. 7. Embodiments need not comprise the same system components. Embodiments need not comprise the system components arranged in the same order. In short, any configuration for communicating a forced flow of treatment gas between treatment gas flow generator12and ventilator30is contemplated by the present disclosure as system10.

FIG. 3is a schematic illustration of system10in a different configuration. In this illustration gas circuit14is configured with two valves so that the flow of gas may optionally circulate through treatment gas remediation system20one or more times.

FIG. 4illustrates system10in a third different example configuration. In this illustration gas flows between treatment gas flow generator12and ventilator30. System10may be connected to/disconnected from ventilator30at inlet interface34and/or outlet interface36.

FIG. 5illustrates system10in a fourth different example configuration. In this illustration gas circuit14is linear. Gas may flow from treatment gas flow generator12, through ventilator30and treatment gas remediation system20, out through exhaust port22.

FIG. 6illustrates system10in a fifth different example configuration. In this illustration gas circuit14is linear. Gas may flow from treatment gas flow generator12through ventilator30and out through exhaust port22.

FIG. 7illustrates system10in a sixth different example configuration. In this illustration gas may flow from treatment gas flow generator12through treatment gas remediation system20and then through ventilator30.

It will be appreciated that the configurations illustrated inFIGS. 1-7are not intended to be limiting. These specific configurations have been provided solely as exemplars of a subset of the potential configurations suitable for delivering treatment gas to a ventilator, or other medical device, to sterilize/disinfect a fluid pathway.

FIG. 8illustrates a method60of providing a flow of treatment gas through a ventilator to sterilize/disinfect a fluid pathway through the ventilator. The operations of method60presented below are intended to be illustrative. In some embodiments, method60may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method60are illustrated inFIG. 8and described below is not intended to be limiting.

At an operation62, a treatment gas flow generator generates a forced flow of treatment gas. In some embodiments, operation62is performed by a treatment gas flow generator the same as or similar to treatment gas flow generator12(shown inFIG. 1and described herein).

At an operation64, the forced flow of treatment gas is conducted to a ventilator via a gas circuit. In some embodiments, operation64is performed by a gas circuit the same as or similar to gas circuit14(shown inFIG. 1and described herein).

At an operation66, a gas circuit interfaces a ventilator fluid pathway inlet such that treatment gas is directed into the fluid pathway of the ventilator. In some embodiments, operation66is performed by a ventilator fluid pathway inlet interface the same as or similar to ventilator fluid pathway inlet interface34(shown inFIG. 1and described herein.)

At an operation68, a gas circuit interfaces a ventilator fluid pathway outlet such that treatment gas is received back into the gas circuit from the fluid pathway of the ventilator. In some embodiments, operation68is performed by a ventilator fluid pathway outlet interface the same as or similar to ventilator fluid pathway outlet interface36(shown inFIG. 1and described herein.)

Although the description provided above provides detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the disclosure is not limited to the expressly disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.