Medical device sterilization system utilizing plasma-based residual alcohol detection

Abstract

A method includes initiating a sterilization process with a sterilizer when a medical device is positioned within a sterilization chamber of the sterilizer. The method further includes monitoring one or more parameters of the sterilization process (e.g., a plasma power profile) to detect whether alcohol is present on or in the medical device. Based on the monitoring, the method further includes determining whether alcohol is present on or in the medical device. If it is determined that alcohol is present on or in the medical device, the method further includes initiating a routine to reduce or eliminate alcohol on or in the medical device. If it is determined that alcohol is not present on or in the medical device, the method further includes completing sterilization of the medical device. The medical device can include an endoscope, such as a gastrointestinal endoscope.

Description

BACKGROUND

[0001] Reusable medical devices, such as certain surgical instruments, endoscopes, and the like, can be sterilized prior to reuse to minimize the possibility of a contaminated device being used on a patient. Various sterilization techniques can be employed, such as steam, hydrogen peroxide, and vapor phase sterilization with or without the use of gas plasma and ethylene oxide (EtO).

[0002] Sterilization of medical devices can be performed with an automated sterilization system, such as the STERRAD® NX® Sterilization System by Advanced Sterilization Products, Inc. of Irvine, California. Systems. Examples of automated sterilization systems are described in U.S. Patent No. 6,939,519, entitled “Power System for Sterilization Systems Employing Low Frequency Plasma,” issued September 6, 2005, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 6,852,279, entitled “Sterilization with Temperature-Controlled Diffusion Path,” issued February 8, 2005, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 6,852,277, entitled “Sterilization System Employing a Switching Module Adapter to Pulsate the Low Frequency Power Applied to a Plasma,” issued February 8, 2005, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 6,447,719, entitled “Power System for Sterilization Systems Employing Low Frequency Plasma,” issued September 10, 2002, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 10,561,753, entitled “Method of Sterilizing Medical Devices, Analyzing Biological Indicators, and Linking Medical Device Sterilization Equipment,” issued February 18, 2020, the disclosure of which is incorporated by reference herein in its entirety; and U.S. Publication No. 2020 / 0230279, entitled “Apparatus and Method for Sterilizing Endoscope,” published July 23, 2020, the disclosure of which is incorporated by reference herein in its entirety. Each different medical device can require a different arrangement and sterilization process.

[0003] Although a variety of systems and methods have been made and used for medical device sterilization, it is believed that no one prior to the inventor(s) has made or used the technology described herein. BRIEF DESCRIPTION OF DRAWINGS

[0004] It is believed that the present application will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify identical elements, and in which:

[0005] Figure 1 depicts a schematic diagram of an example of a sterilization system;

[0006] Figure 2 depicts a schematic diagram of an example of a sterilization cabinet that can be used with Figure 1 the system of

[0007] Figure 3 depicts a flowchart of an example of a set of steps that can be performed by Figure 2 the sterilization cabinet of

[0008] Figure 4 depicts a graph that illustrates an example of a plasma power profile during a sterilization cycle in the absence of residual alcohol in a medical device being sterilized;

[0009] Figure 5 depicts a graph that illustrates an example of a plasma power profile during a sterilization cycle in the presence of residual alcohol on or in a medical device being sterilized; and

[0010] Figure 6 depicts a flowchart of an example of a set of steps that can be performed to detect and address the presence of residual alcohol on or in a medical device in Figure 2 the sterilization cabinet of DETAILED DESCRIPTION

[0011] The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

[0012] It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein can be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. described herein. The above-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein can be combined will be readily apparent to those skilled in the art given the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0013] I. Overview of Sterilization System

[0014] Figure 1 An exemplary system (10) of interconnected devices that can be configured to perform methods associated with sterilizing medical devices (e.g., endoscopes and other medical devices) is depicted. The system (10) of this example includes a sterilization cabinet (100), a biological indicator analyzer (102), a communication hub (20), a server (106), a user device (108), and a sterility guidance database (110). The communication hub (20) is configured to provide data transfer between the sterilization cabinet (100), the biological indicator analyzer (102), the communication hub (20), the server (106), the user device (108), and the sterility guidance database (110), as will be described in greater detail below.

[0015] Figure 2 A set of exemplary components that can be incorporated into the sterilization cabinet (100) is depicted. The sterilization cabinet (100) can be configured to perform one or more sterilization cycles, with different sterilization cycles being suitable for different types and quantities of medical devices (e.g., endoscopes, etc.). The sterilization cabinet (100) of this example includes a sterilization chamber (152) that is configured to house one or more medical devices for sterilization. The sterilization cabinet (100) also includes a sterilant module (156) that is operable to house a sterilant cartridge (158) and to dispense sterilant from the cartridge (158) into the sterilization chamber (152). The sterilization cabinet (100) further includes a touchscreen display (160) that is operable to present various user interface displays and to receive user input in the form of user contact with the touchscreen display (160). The sterilization cabinet (100) can include various other kinds of user input features, including but not limited to buttons, keypads, keyboards, mice, trackballs, etc.

[0016] The sterilization cabinet (100) of the present example further includes a processor (162), a communication module (164), a reader (166), and a memory (168). The processor (162) can include one or more microprocessors and / or various other kinds of hardware, as will be apparent to those of skill in the art in light of the teachings herein. The processor (162) is in communication with various components of the sterilization cabinet (100) and is operable to process data and execute control algorithms to drive the various components of the sterilization cabinet (100). The communication module (164) is configured to enable bidirectional communication between the sterilization cabinet (100) and the communication hub (20). The communication module (164) can also be configured to enable bidirectional communication between the sterilization cabinet (100) and the server (106) and / or the aseptic guidance database (110). The reader (166) is operable to read identification tags of biological indicators and / or other devices as described herein. The memory (168) is operable to store control logic and instructions and is executed by the processor (162) to drive the components of the sterilization cabinet (100). The memory (168) can also be used to store results associated with the execution of the sterilization cycle, the execution of the load conditioning cycle, and / or various other kinds of information. Various suitable components and configurations that can be used to form the processor (162), the communication module (164), the reader (166), and the memory (168) will be apparent to those of skill in the art in light of the teachings herein.

[0017] The sterilization cabinet (100) of the present example further includes a hydrogen peroxide sensor (154) in fluid communication with the sterilization chamber (152) such that the hydrogen peroxide sensor (154) is operable to detect a hydrogen peroxide level within the sterilization chamber (152). In some versions, the hydrogen peroxide sensor (154) utilizes ultraviolet light to detect the hydrogen peroxide level within the sterilization chamber (152). The hydrogen peroxide sensor (154) is in electrical communication with the processor (164) such that the processor (164) can receive signals from the hydrogen peroxide sensor (154) indicative of the hydrogen peroxide level within the sterilization chamber (152). The processor (164) can automatically adjust parameters associated with the sterilization cycle executed by the sterilization cabinet (100) and / or take other actions or refrain from taking certain actions in response to real-time detected levels of hydrogen peroxide within the sterilization chamber (152) detected by the hydrogen peroxide sensor (154).

[0018] The sterilization cabinet (100) of the present example further includes a plasma generator (170) operable to generate plasma within the sterilization chamber (152). The plasma generator (170) is in electrical communication with the processor (164) such that the processor (164) is operable to drive the plasma generator (170). The processor (164) can automatically adjust parameters associated with the plasma generated by the plasma generator (170). Such adjustments associated with the plasma can be based on predetermined sterilization cycle routines stored in the memory (168). Additionally or alternatively, such adjustments associated with the plasma can be based on real-time sensed data. By way of example only, the processor (164) can adjust parameters associated with the plasma generated by the plasma generator (170) based at least in part on real-time data from the hydrogen peroxide sensor (154). In addition to the foregoing, the processor (164) can be configured to track data associated with a power profile driving the plasma generator (170) such that the processor (164) can track data associated directly with the plasma itself in real-time. The processor (164) can further adjust parameters associated with the plasma generated by the plasma generator (170) based at least in part on real-time data from the power profile driving the plasma generator (170).

[0019] In addition to the foregoing, the sterilization cabinet (100) can be configured and operated in accordance with at least some of the teachings of any of the following patent references previously cited herein: U.S. Patent No. 10,668,180, entitled “Apparatus and Method for Sterilizing Medical Devices,” issued June 2, 2020, the disclosure of which is incorporated by reference herein in its entirety; and / or U.S. Patent No. 10,561,753, entitled “Method of Sterilizing Medical Devices, Analyzing Biological Indicators, and Linking Medical Device Sterilization Equipment,” issued February 18, 2020, the disclosure of which is incorporated by reference herein in its entirety.

[0020] In some cases, a biological indicator can be included in the sterilization cabinet (100, 150) along with the medical devices during the sterilization process. The biological indicator can be activated prior to placement such that the microorganisms contained therein reproduce unless it is successfully sterilized during the process. After the sterilization process, the number of microorganisms present in the biological indicator can be determined by the biological indicator analyzer (102) to ensure that the sterilization process was successful for the biological indicator, which will also indicate that the sterilization process was successful for the medical devices. The biological indicator analyzer (102) can receive the biological indicator and measure one or more characteristics of the biological indicator to collect data that can be used to determine whether the biological indicator tests positive, indicating the presence of contamination after the sterilization process, or negative, indicating the absence of contamination after the sterilization process.

[0021] By way of example only, the biological indicators and the biological indicator analyzer (102) can be configured and operated in accordance with at least some teachings of U.S. Patent No. 10,907,126, entitled “Self-Contained Biological Indicator,” issued February 2, 2021, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 10,443,083, entitled “Apparatus and Method for Analyzing Biological Indicators,” issued October 15, 2019, the disclosure of which is incorporated by reference herein in its entirety; U.S. Patent No. 10,561,753, entitled “Method of Sterilizing Medical Devices, Analyzing Biological Indicators, and Linking Medical Device Sterilization,” issued February 18, 2020, the disclosure of which is incorporated by reference herein in its entirety; and / or U.S. Patent No. 10,632,220, entitled “Biological Indicator with Variable Resistance,” issued April 28, 2020, the disclosure of which is incorporated by reference herein in its entirety.

[0022] The server (106) can include a hospital records server or a hospital local area network server. The server (106) can receive information from the sterilization cabinet (100) related to sterilization processes performed by the sterilization cabinet (100), such as sterilization process duration and results; whether a particular sterilization process provided a subsequent indication of biological contamination; identification of the user or technician who initiated, canceled, or completed the sterilization process; consumable materials or supplies used during the sterilization process; diagnostic information and system errors; and / or other information. The server (106) can also receive data from the biological indicator analyzer (102) via the communication hub (20).

[0023] The user device (108) can include a device such as a notebook computer, a desktop computer, a mobile device such as a smart phone, a tablet computer, or other mobile computing device; or a proprietary device having similar capabilities, including such capabilities to wirelessly or wireline communicate with devices such as the communication hub (20), a processor and memory, a display, a user interface, and other capabilities. The user device (108) can be used to access and view information associated with one or more components (100, 102, 110, 106) of the system (10) via the communication hub (20); and can also be used to create or modify configurations and settings of the communication hub (20) and connected devices. A user of the user device (108) can view information and configure devices via, for example, a desktop software application, a mobile device software application, a web browser, or other software interface that can allow the user device (108) to exchange information with the communication hub (20). While only one user device (108) is shown in communication with the communication hub (20), several user devices (108) can also be in communication with the communication hub (20). Similarly, several sterilization cabinets (100), several biological indicator analyzers (102), several servers (106), and several aseptic guidance databases (110) can be in communication with the communication hub (20). Figure 1

[0024] ​The components (100, 102, 110, 106) of the system (10) can each be connected with the communication hub (20) via any suitable wired and / or wireless communication technology, such as Ethernet, Wi-Fi, Bluetooth, USB, infrared, NFC, and / or other technologies. The communication hub (20) can relay data, etc. between the components (100, 102, 110, 106) of the system (10) as described herein, such that the communication hub (20) acts as an intermediary. Various suitable components and configurations that can be used to form the communication hub (20) will be apparent to those skilled in the art in view of the teachings herein. Merely by way of example, the communication hub (20) and / or user device (108) can be configured and operated in accordance with at least some of the teachings of U.S. Patent No. 10,596,287, entitled “Apparatus and Method to Link Medical Device Sterilization Equipment,” issued March 24, 2020, the disclosure of which is incorporated by reference herein in its entirety; and / or U.S. Patent No. 10,561,753, entitled “Method of Sterilizing Medical Devices, Analyzing Biological Indicators, and Linking Medical Device Sterilization Equipment,” issued February 18, 2020, the disclosure of which is incorporated by reference herein in its entirety.

[0025] II. Overview of Sterilization Process

[0026] Figure 3 A set of example steps that the system (10) can perform as a sterilization process to sterilize a medical device (e.g., an endoscope, etc.) are depicted. Initially, the sterilization cabinet (100) can display one or more sterilization cycles via the touchscreen display (160) and then receive a sterilization cycle selection from a user (block 200). The sterilization cabinet (100) can also display instructions indicating whether a biological indicator should be used with the selected sterilization cycle; and receive a biological indicator identification (block 202). The biological indicator can be placed within the sterilization chamber (152) prior to the sterilization cycle beginning, and can remain within the sterilization chamber (152) during the sterilization cycle. Thus, the user can identify the particular biological indicator (block 202) prior to the biological indicator being placed in the sterilization chamber (152).

[0027] The selection of the sterilization cycle (block 200) and the identification of the biological indicator (block 202) can define one or more requirements for the configuration and arrangement of the medical devices within the sterilization cabinet (100). The door of the sterilization chamber (152) can be opened, and instructions can be displayed to guide the user in preparing for the sterilization cycle (block 204), including biological indicator placement, medical device placement, closing the door of the sterilization chamber (152), and / or other changes in preparation. Prior to initiating the actual sterilization cycle (block 208), the sterilization cabinet (100) can also perform a load conditioning (block 206) of the medical devices loaded in the sterilization chamber (152). This load conditioning (block 206) can include verifying that the sterilization chamber (152) is sealed; verifying the contents of the sterilization chamber (152); checking physical characteristics of the sterilization chamber (152) contents, such as moisture level, volume of contents, weight of contents, internal temperature, or other characteristics; and / or performing one or more conditioning steps, which can include heat treatment, chemical treatment, plasma treatment, or other types of treatment to reduce moisture, raise temperature, and / or otherwise prepare the medical devices in the sterilization chamber (152) for the sterilization cycle.

[0028] Once the load conditioning (block 206) has been completed, the selected sterilization cycle itself (block 208) can be performed. The sterilization cycle (block 208) can include exposing the medical device(s) in the sterilization chamber (152) to pressurized sterilant gas (e.g., hydrogen peroxide vapor, etc.), further heat treatment, chemical treatment, plasma treatment, vacuum treatment, and / or other types of sterilization processes. Upon completion of the sterilization cycle (block 208), the complete sterilization results can be displayed to the user via the touchscreen display (160); transmitted to the server (106); printed locally; and / or displayed, transmitted, and / or stored via other possible and desirable devices. While block 208 is shown and described herein as a "sterilization cycle," the entire process shown in FIG. 2 - including all of the steps (blocks 200, 202, 204, 206, 208, 210) of the process - can generally be understood as a "sterilization process" Figure 3 The entire process shown in FIG. 2 - including all of the steps (blocks 200, 202, 204, 206, 208, 210) of the process - can generally be understood as a "sterilization process"

[0029] The sterilization cabinet (100) can also provide results of the sterilization cycle (block 210). The providing of results (block 210) can include results from analysis of the biological indicators via the biological indicator analyzer (102). These results can include a positive or negative indication of contamination present in the biological indicators at completion of the sterilization cycle (block 208). In cases where the biological indicators indicate contamination present after completion of the sterilization cycle (block 208), additional actions can be taken, such as alerting a user of a positive test and analysis of the sterilization cycle history to determine whether other past cycles can have been the cause of the contamination; and / or whether medical devices sterilized thereafter can need to be re-sterilized.

[0030] III. Detecting and addressing residual alcohol on or in medical devices in a sterilization system

[0031] In some cases, medical devices to be sterilized in the sterilization chamber (152) can undergo a reprocessing phase prior to being placed in the sterilization chamber (152). This reprocessing phase can include placing the medical devices in a reprocessing system in which the medical devices are cleaned and disinfected. By way of example only, such reprocessing can be performed in accordance with at least some teachings of: U.S. Pub. No. 2017 / 0332891, entitled “Apparatus and method to Identify Endoscope Type and Provide Tailored Reprocessing,” published November 23, 2017, now abandoned, the disclosure of which is incorporated by reference herein in its entirety; U.S. Pat. No. 10,201,269, entitled “Apparatus and Method for Reprocessing a Medical Device,” issued February 12, 2019, the disclosure of which is incorporated by reference herein in its entirety; U.S. Pat. No. 10,328,170, entitled “Dynamic Disinfectant Dosage with Concentrate Degradation Compensation,” issued June 25, 2019, the disclosure of which is incorporated by reference herein in its entirety; and / or U.S. Pat. No. 10,702,619, entitled “Apparatus and Method to Measure Concentration of Disinfectant in Medical Device Reprocessing System,” issued July 7, 2020, the disclosure of which is incorporated by reference herein in its entirety.

[0032] As part of the reprocessing stage, the medical device can be exposed to alcohol (e.g., isopropyl alcohol) as a disinfectant and / or to help dry the medical device. In some instances, some residual alcohol can be present on or in the medical device. In the context of an endoscope (e.g., a gastroenterological endoscope), some of this residual alcohol can remain in one or more working channels of the endoscope. Placing a medical device with residual alcohol in the sterilization chamber (152) and then activating the sterilization process in a case where residual alcohol remains on or in the medical device can result in undesirable consequences. For example, the presence of alcohol in the sterilization chamber (152) during the sterilization process can cause instability in the plasma generated by the plasma generator (170). For example, Figure 4 A plot (310) of a power profile associated with plasma generated by the plasma generator (170) in the sterilization chamber (152) is depicted, such as during load regulation (block 206) or during a sterilization cycle (block 208), when the medical device in the sterilization chamber (152) does not have residual alcohol. As shown, the power delivered to the plasma generator (170) maintains a steady value of approximately 500 Watts during a region (312) of the plot (310) in which the power reaches a lower threshold (320) associated with plasma generation. By way of example only, an acceptable range of plasma power can span from approximately 450 Watts to approximately 550 Watts, such that the threshold (320) can be approximately 450 Watts.

[0033] In contrast, Figure 5A plot (350) is depicted that shows a plot (360) of a power profile associated with the plasma generated by the plasma generator (170) in the sterilization chamber (152) when the medical device in the sterilization chamber (152) has an amount of residual alcohol, e.g., during load conditioning (block 206) or during a sterilization cycle (block 208). As shown, the power delivered to the plasma generator (170) becomes unstable during a first region (362) of the plot (360) in which the power has reached the lower threshold (320) associated with plasma generation and even falls below 450 Watts (as noted above, this can represent the minimum power level for generating plasma), although the power eventually reaches a steady value of approximately 500 Watts during a second region (364) of the plot (360) in which the power reaches the lower threshold (320) associated with plasma generation. The power delivered to the plasma generator (170) can be unstable during the first region (362) of the plot (360) due to the presence of alcohol affecting the impedance at the electrodes (not shown) of the plasma generator (170). Although a steady value of the plasma power profile is eventually achieved, it can be desirable to avoid this unstable phase of the power profile so that the profile associated with the plot (300) is achieved on a consistent basis. While the plot (360) shows a power level that reaches the lower threshold (320) associated with plasma generation before becoming unstable, there can be scenarios in which the plasma power profile becomes unstable before reaching the lower threshold (320) associated with plasma generation.

[0034] Additionally or alternatively, the presence of alcohol on or in the medical device during the sterilization process can cause premature degradation of the medical device being sterilized in the sterilization chamber (152). Additionally or alternatively, the presence of alcohol in the sterilization chamber (152) during the sterilization process can impair the effectiveness of the sterilization process. Additionally or alternatively, the presence of alcohol in the sterilization chamber (152) during the sterilization process can create a safety risk during subsequent use of the medical device. For at least the foregoing reasons, it can be desirable to provide a version of the sterilization cabinet (100) and method of operating the sterilization cabinet (100) in which it is possible to detect the presence of alcohol in the sterilization chamber (152) prior to the sterilization process being initiated or completed. Similarly, it can be desirable to provide a version of the sterilization cabinet (100) and method of operating the sterilization cabinet (100) in which it is possible to eliminate any alcohol detected in the sterilization chamber (152) prior to the sterilization process being initiated or completed.

[0035] As noted above in the description of the sterilization cabinet (100) and method of operating the sterilization cabinet (100), the sterilization cabinet (100) can be configured to detect the presence of alcohol in the sterilization chamber (152) prior to the sterilization process being initiated or completed. The sterilization cabinet (100) can be configured to eliminate any alcohol detected in the sterilization chamber (152) prior to the sterilization process being initiated or completed. The sterilization cabinet (100) can be configured to detect the presence of alcohol in the sterilization chamber (152) prior to the sterilization process being initiated or completed and eliminate any alcohol detected in the sterilization chamber (152) prior to the sterilization process being initiated or completed. Figures 5-6As noted in the comparison of the graphs (300, 350), the presence of alcohol on the medical device in the sterilization chamber (152) or in the medical device may affect the power profile associated with the plasma generated by the plasma generator (170) in the sterilization chamber (152). Therefore, the presence of alcohol in the sterilization chamber (152) can be detected by monitoring the power profile associated with the plasma generated in the sterilization chamber (152). Such monitoring can be performed by any other suitable hardware component of the processor (162) and / or the sterilization cabinet (100), which will be apparent to those skilled in the art in light of the teachings herein. Figure 6 A method (400) is described by which such monitoring can be performed. By way of example only, the method (400) may be performed as part of a load conditioning phase (box 206), as part of a sterilization cycle (box 208), and / or at any other suitable time. By way of further example only, the method (400) may be performed before the load conditioning phase (box 206).

[0036] like Figure 6 As shown, the method (400) begins by activating the plasma via a plasma generator (170) (box 410). As power is delivered to the plasma generator (170), a power profile is monitored (box 420) to determine whether the power remains stable after crossing a threshold (320) associated with plasma generation (e.g., as shown). Figure 4 (as shown in region (312) of the plot (310)); or determine whether the power becomes unstable after crossing a threshold (320) associated with plasma generation (e.g., as shown in the plot (310)); Figure 5 As shown in area (362) of the plot (360). As noted above, this monitoring (box 420) can be performed by the processor (162). If the processor (162) determines (box 430) that the power profile is acceptable, the method (400) can continue (box 440) the normal sterilization routine. If the method (400) is performed before or as part of the load conditioning (box 206), the sterilizer (100) can continue (box 440) the load conditioning (box 206) at this time. If the method (400) is performed between the load conditioning (box 206) and the sterilization cycle (box 208), the sterilizer (100) can continue (box 440) the sterilization cycle (box 208) at this time. Alternatively, the sterilizer (100) may continue (box 440) to any other stage of the sterilization routine that may follow the method (400), as will be apparent to those skilled in the art in light of the teachings herein.

[0037] In the event that the processor (162) determines (block 430) that the plasma power profile is not acceptable, such that the power profile test (block 430) has failed, then the processor (162) can determine (block 450) whether a failure limit has been reached. As described below, the sterilization cabinet (100) can iterate through a routine to attempt to eliminate residual alcohol on or in the medical device in the sterilization chamber (152), although a limit can be set on how many such iterations can be performed before the process is to be halted (block 460). In some versions, the method (400) is configured such that up to four failures of the power profile test (block 430) can be tolerated; however, five or more failures are not acceptable. Alternatively, any other suitable failure limit can be used. Regardless of which failure limit is used, the method (400) can be halted (block 460) in the event that the failure limit has been reached. In the event that the method (400) is halted (block 460), the processor (162) can drive the touchscreen display (160) to inform the operator that residual alcohol has been detected and cannot be removed; and further instruct the operator to retrieve the medical device from the sterilization chamber (152) and return the medical device through a reprocessing system before reintroducing the medical device to the sterilization chamber (152). Alternatively, in the event that the method (400) is halted, the operator can be prompted to take any other suitable action (block 460).

[0038] In the event that the processor (162) determines (block 430) that the plasma power profile is not acceptable and further determines (block 450) that the failure limit has not been reached, the processor (162) can drive the touchscreen display (160) to inform the operator that residual alcohol has been detected, and that the sterilization cabinet (100) will attempt to remove the residual alcohol (e.g., via the load conditioning block (206)). The processor (162) can further extinguish the plasma (block 470) by deactivating the plasma generator (170). The processor (162) can then evacuate the sterilization chamber (152) (block 480). By way of example only, the sterilization chamber (152) can be vented to the atmosphere, additionally or alternatively, a vacuum can be applied to the sterilization chamber (152) to evacuate the sterilization chamber (152) (block 480). By way of example only, the sterilization chamber (152) can be actively evacuated (e.g., via a vacuum pump) for about one minute.

[0039] Once the sterilization chamber (152) has been sufficiently evacuated (block 480), the method (400) can be reinitiated by another iteration by activating the plasma in the sterilization chamber (152) (block 410). To achieve plasma reactivation (block 410), the sterilization chamber (152) can first be vented (block 490) to achieve a plasma ignition pressure of about 500 mT, followed by activating the plasma generator (170) to ignite the plasma (block 410).

[0040] In some cases, the process of extinguishing the plasma (block 470), evacuating the sterilization chamber (152) (block 480), and reactivating the plasma (block 410) can reduce or eliminate residual alcohol on or in the medical device in the sterilization chamber (152). In some variations, the method (400) can include additional steps as part of the process to remove residual alcohol from the medical device. For example, the sterilization cabinet (100) can pass warm, dry air through the sterilization chamber (152) and circulate over the medical device for a predetermined period. Additionally or alternatively, the method (400) can provide for repeated steps of evacuating (block 480) the sterilization chamber (152) and venting (block 490) the sterilization chamber (152) in a pulsed manner prior to reactivating the plasma (block 410). Additionally or alternatively, the method (400) can provide for venting of the sterilization chamber (152) to atmosphere, then holding the pressure in the sterilization chamber (152) at atmosphere for a predetermined period to allow for warm air convection in the sterilization chamber (152); followed by evacuating the sterilization chamber (152) to remove vaporized alcohol. Additionally or alternatively, the method (400) can provide for maintenance of a fixed pressure (e.g., about 500 mT) in the sterilization chamber (152) for a predetermined period of time. Similarly, the method (400) can isolate the sterilization chamber (152) at the fixed pressure and monitor the rise in pressure in the sterilization chamber (152) to determine whether moisture has been removed or whether moisture remains present in the sterilization chamber (152) (e.g., affected by the presence of moisture on or in the medical device in the sterilization chamber (152)). Alternatively, any other steps can be taken to address the presence of residual alcohol on or in the medical device in the sterilization chamber (152) in addition to or in lieu of the various steps described above.

[0041] In some cases where steps have been taken to attempt to remove residual alcohol, the method (400) can provide a longer duration of reactivated plasma (block 410) in a second or subsequent iteration of the method (400). This longer duration of reactivated plasma (block 410) can be calculated to compensate for the time spent during the steps of extinguishing the plasma (block 470), evacuating (block 480), and venting (block 490) (and any other steps that have been taken in an attempt to remove residual alcohol). In other words, the processor (162) can integrate the plasma power profile versus time to ensure that the total required power as can be expected has been delivered in the load regulation (block 206) or sterilization cycle (block 208) without the presence of residual alcohol in the medical device.

[0042] As noted above, the method (400) can be repeated iteratively until either a failure limit has been reached (due to persistent residual alcohol) or the plasma power profile has been found to be acceptable (due to eventual absence of residual alcohol).

[0043] In some variations of the method (400), it can be determined in the first iteration that there is too much residual alcohol within the sterilization chamber (152) (due to an excess of residual alcohol on or in the medical device within the sterilization chamber (152)) such that the sterilization process should be aborted without even attempting the iterations described above to remove residual alcohol. By way of example only, the processor (162) can determine that the amount of residual alcohol is “excessive” if two or more conditions are met. One such condition can include the unstable plasma power profile described above with reference to FIG. 4. Another such condition can include an excessively long sterilization chamber (152) evacuation time to reach a target plasma pressure (e.g., about 500 mT). Examples of suitable time thresholds for determining whether such a time is “excessive” will be apparent to those of skill in the art in view of the teachings herein. If both conditions are found in the same cycle, the processor (162) can determine that the amount of residual alcohol is “excessive” and can abort the sterilization process without attempting the iterations described above to remove residual alcohol. Figure 5

[0044] ​In some variations of the method (400), in addition to monitoring plasma power, or as an alternative to monitoring plasma power, some other parameter can be monitored to determine whether residual alcohol is on or in the medical device in the sterilization chamber (152). By way of example only, in versions in which hydrogen peroxide vapor is used as the sterilant during the sterilization cycle (block 208), the processor (162) can track the signal from the hydrogen peroxide sensor (154) to determine whether the hydrogen peroxide degradation follows the expected curve, or whether the hydrogen peroxide vapor is degrading at a rate that deviates from the expected degradation curve. When alcohol is present on or in the medical device in the sterilization chamber (152), the hydrogen peroxide vapor in the sterilization chamber (152) can degrade more quickly than would be expected in other cases. Thus, a significant deviation from the expected curve of hydrogen peroxide degradation can be indicative of the presence of alcohol on or in the medical device in the sterilization chamber (152). The processor (162) can incorporate such real-time data from the hydrogen peroxide sensor (154) into variations of the method (400). By way of example only, in addition to or in lieu of the plasma power profile, real-time data from the hydrogen peroxide sensor (154) can be analyzed as part of the determination (block 430) of whether residual alcohol is present on or in the medical device in the sterilization chamber (152).

[0045] IV. EXEMPLARY COMBINATIONS

[0046] The following examples relate to various non-exhaustive ways in which the teachings herein can be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that can be presented at any time in this application or in subsequent filings of related applications. No disclaimer is intended. The following examples are being provided only for the purpose of illustrating various aspects of the teachings herein. It is contemplated that various teachings herein can be combined or applied in a variety of ways. It is also contemplated that some embodiments can omit certain features referred to in the following examples. Accordingly, the following examples are not intended to limit the scope of the claims to the embodiments actually described. If claims are presented in this application or in subsequent filings of related applications that include additional features beyond those described below, such additional features shall not be read into the claims presented herein or in the claims of any subsequent filings of related applications.

[0047] Example 1

[0048] A method comprising: (a) initiating a sterilization process with a sterilizer when a medical device is positioned within a sterilization chamber of the sterilizer; (b) monitoring one or more parameters of the sterilization process to detect whether alcohol is present on or in the medical device; (c) either: (i) determining, based on the monitoring, that alcohol is present on or in the medical device, or (ii) determining, based on the monitoring, that alcohol is not present on or in the medical device; and (d) either: (i) initiating a routine to reduce or eliminate alcohol on or in the medical device if it is determined that alcohol is present on or in the medical device, (ii) completing sterilization of the medical device if it is determined that alcohol is not present on or in the medical device, or (iii) aborting the sterilization process if it is determined that an amount of alcohol is present on or in the medical device.

[0049] Example 2

[0050] The method of Example 1, the medical device comprising an endoscope.

[0051] Example 3

[0052] The method of Example 2, the endoscope comprising a gastrointestinal endoscope.

[0053] Example 4

[0054] The method of any one of Examples 1-3, the sterilization process comprising a load conditioning cycle followed by a sterilization cycle.

[0055] Example 5

[0056] The method of Example 4, the load conditioning cycle comprising one or both of reducing moisture in the medical device or increasing a temperature of the medical device.

[0057] Example 6

[0058] The method of any one of Examples 4-5, the monitoring being performed during the load conditioning cycle.

[0059] Example 7

[0060] The method of any one of Examples 4-6, the monitoring being performed during the sterilization cycle.

[0061] Example 8

[0062] The method of any one of Examples 1-7, the sterilization process comprising applying plasma to the sterilization chamber.

[0063] Example 9

[0064] The method of example 8, the monitoring comprising monitoring a power profile associated with the plasma.

[0065] Example 10

[0066] The method of example 9, wherein determining that alcohol is present comprises determining that the power profile associated with the plasma becomes unstable before or after a power level reaches a threshold associated with plasma generation.

[0067] Example 11

[0068] The method of example 9, wherein determining that alcohol is not present comprises determining that the power profile associated with the plasma remains stable after a power level reaches a threshold associated with plasma generation.

[0069] Example 12

[0070] The method of any of examples 8-11, the routine to reduce or eliminate alcohol on or in the medical device comprising extinguishing the plasma.

[0071] Example 13

[0072] The method of any of examples 11-12, the routine to reduce or eliminate alcohol on or in the medical device comprising evacuating the sterilization chamber.

[0073] Example 14

[0074] The method of example 13, wherein evacuating the sterilization chamber comprises applying a vacuum to the sterilization chamber.

[0075] Example 15

[0076] The method of any of examples 1-14, the sterilization process comprising delivering hydrogen peroxide vapor to the sterilization chamber.

[0077] Example 16

[0078] The method of example 15, the monitoring comprising monitoring a degradation curve associated with the hydrogen peroxide vapor.

[0079] Example 17

[0080] The method of example 16, wherein determining that alcohol is present comprises determining that a rate of degradation of the hydrogen peroxide vapor exceeds an expected degradation curve.

[0081] Example 18

[0082] The method of any of examples 1-17, the routine to reduce or eliminate alcohol on or in the medical device comprising evacuating the sterilization chamber.

[0083] Example 19

[0084] The method of example 18, wherein evacuating the sterilization chamber comprises applying a vacuum to the sterilization chamber.

[0085] Example 20

[0086] The method of any one of examples 1-19, further comprising, if it is determined that alcohol is present on or in the medical device, performing a subsequent iteration of at least a portion of the sterilization process after initiating a routine to reduce or eliminate alcohol on or in the medical device.

[0087] Example 21

[0088] The method of example 20, further comprising monitoring one or more parameters of the sterilization process to detect whether alcohol is present on or in the medical device during the subsequent iteration.

[0089] Example 22

[0090] The method of example 21, further comprising: (a) determining, based on the monitoring, that alcohol is still present on or in the medical device during the subsequent iteration; (b) determining whether a predetermined number of iterations of the at least a portion of the sterilization process has been performed; and (c) either: (i) initiating a routine to reduce or eliminate alcohol on or in the medical device if the predetermined number of iterations has not been performed, or (ii) aborting the sterilization process if the predetermined number of iterations has been performed.

[0091] Example 23

[0092] The method of example 22, wherein aborting the sterilization process comprises prompting an operator to remove the medical device from the sterilization chamber.

[0093] Example 24

[0094] The method of any one of examples 1-23, wherein the method is performed by a processor of the sterilizer.

[0095] Example 25

[0096] A method comprising: (a) generating a plasma within a sterilization chamber of a sterilizer when a medical device is positioned within the sterilization chamber; (b) monitoring a power profile associated with the plasma to detect whether alcohol is present on or in the medical device; and (c) determining, using a processor, whether alcohol is present on or in the medical device based on the monitored power profile.

[0097] Example 26

[0098] The method of example 25, wherein the determination of whether alcohol is present on or in the medical device using the processor results in a determination that alcohol is present on or in the medical device, the method further comprising initiating a routine to reduce or eliminate alcohol on or in the medical device.

[0099] Example 27

[0100] The method of example 26, the routine to reduce or eliminate alcohol on or in the medical device comprising extinguishing a plasma.

[0101] Example 28

[0102] The method of any of examples 26-27, the routine to reduce or eliminate alcohol on or in the medical device comprising evacuating the sterilization chamber.

[0103] Example 29

[0104] The method of example 25, wherein the determination of whether alcohol is present on or in the medical device using the processor results in a determination that alcohol is not present on or in the medical device, the method further comprising completing sterilization of the medical device.

[0105] Example 30

[0106] The method of any of examples 25-29, wherein the determination of whether alcohol is present on or in the medical device using the processor based on the monitored power profile comprises determining whether the power profile associated with the plasma remains stable or becomes unstable before or after a power level reaches a threshold value associated with plasma generation.

[0107] Example 31

[0108] A system comprising: (a) a sterilization chamber operable to house a medical device; and (b) a processor operable to drive a sterilization process on a medical device within the sterilization chamber, the processor further configured to: (i) monitor one or more parameters of the sterilization process to detect whether alcohol is present on or in the medical device, (ii) based on the monitoring, determine whether alcohol is present on or in the medical device, and (iii) based on whether alcohol is determined to be present on or in the medical device, do either of: (A) initiate a routine to reduce or eliminate alcohol on or in the medical device, (B) complete sterilization of the medical device, or (C) abort the sterilization process if a quantity of alcohol is determined to be present on or in the medical device.

[0109] Example 32

[0110] The system of example 31, further comprising a plasma generator operable to generate plasma in the sterilization chamber.

[0111] Example 33

[0112] The system of example 32, the processor operable to drive the plasma generator.

[0113] Example 34

[0114] The system of any of examples 32-33, the processor further configured to monitor a power profile associated with driving of the plasma generator.

[0115] Example 35

[0116] The system of example 34, the processor configured to determine whether alcohol is present on or in the medical device based on behavior of the power profile before or after a power level reaches a threshold value associated with plasma generation.

[0117] Example 36

[0118] The system of example 35, the processor configured to determine that alcohol is present on or in the medical device based on the power profile becoming unstable before or after a power level reaches a threshold value associated with plasma generation.

[0119] Example 37

[0120] The system of any of examples 35-36, the processor configured to determine that alcohol is not present on or in the medical device based on the power profile remaining stable after a power level reaches a threshold value associated with plasma generation.

[0121] Example 38

[0122] The system of any of examples 31-37, the processor configured to extinguish plasma as part of a routine to reduce or eliminate alcohol on or in the medical device.

[0123] Example 39

[0124] The system of any of examples 31-38, the processor configured to evacuate the sterilization chamber as part of a routine to reduce or eliminate alcohol on or in the medical device.

[0125] Example 40

[0126] The system of example 39, the processor configured to trigger a vacuum in the sterilization chamber to evacuate the sterilization chamber as part of a routine to reduce or eliminate alcohol on or in the medical device.

[0127] V. Miscellaneous

[0128] It should be appreciated that any patent, publication, or other disclosure material (in whole or in part) herein expressly incorporated by reference is incorporated only to the extent that the incorporated material is not inconsistent with existing definitions, statements, or other disclosure material expressly set forth in the present disclosure. In the event of inconsistent usages between this incorporated material and the present disclosure, the usage in the present disclosure controls. If a section heading or caption is used, the accompanying text is to be interpreted as describing only the sub-section under the heading or caption. Only claims or other patenting matters which are explicitly incorporated by reference are part of the disclosure of the present application. Material which is presented and described only in the Example Section (e.g., Examples 1-3) is not to be construed as constituting prior art nor is it considered to be part of the disclosure of the present application.

[0129] Having shown and described various embodiments of the present application, further adaptations and modifications of the methods and systems described herein are possible. Several of such potential modifications have already been mentioned, such as the use of different materials, sizes, shapes, and so on. Other modifications, which are within the spirit and scope of the present application will be apparent to those skilled in the art from this disclosure. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative. As such, the scope of the present application should be considered in terms of the following claims, by themselves and in light of the prior art.

Claims

1. A system for sterilization, comprising: A chamber operable to contain equipment to be sterilized; and A processor operable to drive the sterilization process, and further configured to: Alcohol in the equipment or device is detected based on plasma power profiles or hydrogen peroxide degradation curves during the sterilization process, which are affected by residual alcohol. and In response to the detection of alcohol, a program is run to remove at least a portion of the alcohol from the device or the device.

2. The system according to claim 1, further comprising: A plasma generator coupled to the processor is operable to generate plasma in the chamber.

3. The system of claim 2, wherein the processor is further configured to: Alcohol is detected based on the characteristics of plasma power profiles.

4. The system according to claim 1, further comprising: A hydrogen peroxide sensor coupled to the processor is operable to detect the hydrogen peroxide level within the chamber.

5. The system of claim 4, wherein the processor is further configured to: Alcohol is detected by comparing degradation rate with expected degradation curve.

6. The system according to claim 1, further comprising: A vacuum pump, coupled to the processor, is operable to evacuate the chamber.

7. The system according to claim 6, wherein, The processor is further configured to: The chamber is evacuated by a vacuum pump to remove at least a portion of the alcohol.

8. The system according to claim 1, wherein, The processor is further configured to: This causes the sterilization process to stop.

9. A sterilization method that can be performed by a sterilizer for sterilizing equipment located within the chamber of the sterilizer, comprising: Alcohol in the equipment or apparatus is detected based on plasma power profiles or hydrogen peroxide degradation curves during the sterilization process, which are affected by residual alcohol; and In response to the detection of alcohol, a program is run to remove at least a portion of the alcohol from the device or the device.

10. The sterilization method according to claim 9, wherein the detection step comprises: Alcohol is detected based on the characteristics of plasma power profiles.

11. The sterilization method according to claim 9, wherein the detection step comprises: Alcohol is detected by comparing degradation rate with expected degradation curve.

12. The sterilization method according to claim 9, wherein the detection step comprises: Monitoring plasma power profiles and hydrogen peroxide degradation rates during the sterilization process; and Alcohol is detected based on (i) the characteristics of the plasma power profile and (ii) the deviation of the degradation rate from the expected degradation curve.

13. The sterilization method according to claim 9, wherein the operating steps include: The sterilization chamber of the sterilizer is evacuated to remove at least a portion of the alcohol.

14. The sterilization method according to claim 9, wherein the operating steps include: The plasma in the sterilization chamber of the sterilizer is extinguished; Evacuate the sterilization chamber; and The plasma is reactivated in the sterilization chamber.

15. The sterilization method according to claim 9, wherein the operating steps include: Air is circulated through the sterilization chamber of the sterilizer or above the equipment for a predetermined period of time.

16. The sterilization method according to claim 9, wherein the operating steps include: The sterilization process is stopped so that at least a portion of the alcohol can be removed to the outside of the sterilization chamber of the sterilizer.

17. The sterilization method of claim 9, wherein the plasma power profile during the sterilization process includes a power profile related to plasma generation, or a evacuation time to reach the target plasma pressure; and wherein the operating steps include: The sterilization process is terminated in response to (i) an unstable power profile or (ii) an evacuation time exceeding a threshold.

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