Apparatus and method for sterilizing an endoscope

Abstract

To sterilize a medical device.SOLUTION: A method of sterilizing an article such as a flexible endoscope is implemented in a sterilization chamber. A vacuum is applied in the sterilization chamber while the article is contained in the sterilization chamber. A sterilant is then introduced into the sterilization chamber. The pressure within the sterilization chamber is incrementally increased to provide a step-wise transition from a high vacuum state to atmospheric pressure. The article is thereby sterilized.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] Some reusable medical devices, such as surgical instruments, endoscopes, etc., may be sterilized before reuse to minimize the likelihood that contaminated devices will be used on a patient, which could lead to patient infection. Various sterilization methods can be used, such as steam, hydrogen peroxide, peracetic acid, and vapor phase sterilization, with or without gas plasma or ethylene oxide (EtO). Each of these methods may depend in part on the rate of diffusion of a sterilizing fluid (e.g., gas) onto or into the medical device being sterilized.

[0002] Prior to sterilization, medical devices may be packaged in a container or pouch with a semi-permeable barrier that allows the delivery of a sterilizing fluid, also referred to as a sterilant, but prevents the ingress of contaminating microorganisms, among other things, after sterilization and until the container is opened by a medical professional. For a sterilization cycle to be effective, contaminating microorganisms within the container must be killed, as some microorganisms that survive the sterilization cycle may grow and recontaminate the medical device. Diffusion of sterilant can be particularly problematic for medical devices with diffusion-restricted spaces, as these spaces can reduce the likelihood that a sterilization cycle can be effective. For example, some endoscopes have one or more long, narrow lumens through which the sterilant must diffuse in sufficient concentration for a sufficient time to complete a successful sterilization cycle.

[0003] Sterilization of medical devices can be performed by an automated sterilization system, such as the STERRAD® system by Advanced Sterilization Products of Irvine, Calif. Examples of automated sterilization systems are described in U.S. Patent No. 6,939,519, issued September 6, 2005, entitled "Power System for Sterilization Systems Employing Low Frequency Plasma," the disclosure of which is incorporated herein by reference; U.S. Patent No. 6,852,279, issued February 8, 2005, entitled "Sterilization with Temperature-Controlled Diffusion Path," the disclosure of which is incorporated herein by reference; U.S. Patent No. 6,852,279, issued February 8, 2005, entitled "Sterilization System Employing a Switching Module Adapter to Pulsate the Low Frequency Power Applied to a No. 6,852,277 entitled "Sterilization System Using a Switching Module Adapter for Oscillating Low Frequency Power Applied to a Plasma"; U.S. Patent No. 6,447,719 entitled "Power System for Sterilization Systems Employing Low Frequency Plasma," issued on September 10, 2002, the disclosure of which is incorporated herein by reference; and U.S. patent application Ser. No. 62 / 316,722 entitled "System and Method for Sterilizing Medical Devices," filed on April 1, 2016, the disclosure of which is incorporated herein by reference.

[0004] Some sterilization systems may sterilize medical instruments using, for example, vaporized chemical sterilants or chemical gases such as hydrogen peroxide, peracetic acid, ozone, chlorine dioxide, and nitrogen dioxide. Examples of such systems are described in U.S. Pat. No. 6,365,102, entitled "Method of Enhanced Sterilization with Improved Material Compatibility," issued on April 2, 2002, the disclosure of which is incorporated herein by reference, and U.S. Pat. No. 6,325,972, entitled "Apparatus and Process for Concentrating a Liquid Sterilant and Sterilizing Articles Therewith," issued on December 4, 2001, the disclosure of which is incorporated herein by reference. Some such systems provide a hydrogen peroxide / gas plasma sterilization system that includes a vacuum chamber and a plasma source, resulting in an increased concentration of hydrogen peroxide for sterilization. Some such systems may have difficulty sterilizing the lumens of some medical instruments when their length exceeds a certain value, or the processing time of such systems may still not be fast enough for some applications. Thus, some medical instruments, such as long and / or thin flexible endoscopes, may not be completely sterilized with these systems due to insufficient sterilizing steam reaching the interior of the channels. Such medical instruments may therefore only be disinfected without being sterilized. Sterilization systems using ethylene oxide may have relatively long processing times (e.g., greater than 24 hours), which may be undesirable in some cases.

[0005] Due to operator misunderstanding, medical devices may be returned to service thinking they have been decontaminated. Ensuring that the sterilization cycle is effective can help prevent medical personnel from using contaminated medical devices on patients. Medical devices may not be checked for the presence of contaminating microorganisms after sterilization, as this may introduce additional contaminating microorganisms to the medical device and recontaminate it. Therefore, an indirect check may be performed using a sterilization indicator. A sterilization indicator is a device that can be placed with or near a medical device undergoing a sterilization cycle, so that the sterilization indicator undergoes the same sterilization cycle as the medical device. For example, a biological indicator containing a predetermined amount of microorganisms can be placed with a medical device in a sterilization chamber and subjected to a sterilization cycle. After the cycle is completed, the microorganisms in the biological indicator can be cultured to determine whether any microorganisms survived the cycle. The presence or absence of viable microorganisms in the biological indicator indicates whether the sterilization cycle was effective.

[0006] While various systems and methods have been made and used in the past for sterilizing surgical instruments, it is believed that no one prior to the present inventors has made or used the techniques described herein. [Brief description of the drawings]

[0007] The invention will be better understood from the following description of several embodiments taken in conjunction with the accompanying drawings, in which like reference numbers identify the same elements and in which: [Figure 1] 1 shows a schematic diagram of an exemplary medical device sterilization cabinet. [Diagram 2] 2 shows a high-level flowchart of an exemplary set of steps that the sterilization cabinet of the system of FIG. 1 may perform to sterilize medical instruments. [Diagram 3] 3 shows a flow chart of an exemplary set of steps that may be performed as part of a sterilization cycle within the set of steps of FIG. 2. [Figure 4] 4 depicts a graph showing an exemplary plot of reduced pressure within the sterilization chamber of the sterilization cabinet of FIG. 1 over time during the performance of the sterilization cycle of FIG. 3. [Diagram 5] 3 shows a flow chart of an exemplary alternative set of steps that may be performed as part of a sterilization cycle within the set of steps of FIG. 2. [Figure 6] 6 depicts a graph showing another exemplary plot of reduced pressure within the sterilization chamber of the sterilization cabinet of FIG. 1 over time during the performance of the sterilization cycle of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The following description of a specific embodiment of the present technology should not be used to limit the scope of the present technology. Other embodiments, features, aspects, embodiments, and advantages of the present technology will be apparent to those skilled in the art from the following description, which is illustrative and is one of the best modes contemplated for carrying out the present technology. As will be understood, the present technology described herein is capable of various other obvious aspects, all without departing from the present technology. Thus, the drawings and description should be regarded as illustrative in nature, not restrictive.

[0009] It should further be 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. Thus, the teachings, expressions, embodiments, examples, etc. described below should not be considered in isolation with respect to each other. In light of the teachings herein, various suitable ways in which the teachings herein can be combined will be apparent to those skilled in the art. Such modifications and variations are intended to be included within the scope of the claims.

[0010] I. Overview of an Exemplary Sterilization System FIG. 1 illustrates an exemplary sterilization cabinet (150) operable to sterilize medical instruments, such as an endoscope. The sterilization cabinet (150) of this example includes a sterilization chamber (152) configured to receive one or more medical instruments for sterilization. Although not shown, the sterilization cabinet (150) also includes a door that opens and closes the sterilization chamber (152) in response to actuation of a kick plate. This allows an operator to open and close the sterilization chamber (152) in a hands-free manner. Of course, any other suitable mechanism may be used to provide selective access to the sterilization chamber. The sterilization cabinet (150) also includes a sterilization module (156) operable to dispense a sterilant into the sterilization chamber (152) to sterilize the medical instruments stored therein. In this example, the sterilization module (156) is configured to receive a replaceable sterilant cartridge (158) containing a quantity of sterilant. For illustrative purposes only, each sterilant cartridge (158) can store enough sterilant to perform five sterilization processes.

[0011] Additionally, the example sterilization cabinet (150) also includes a touchscreen display (160). The touchscreen display (160) is operable to render a variety of user interface display screens, such as those described in U.S. Provisional Patent Application No. 62 / 316,722, the disclosure of which is incorporated herein by reference. Of course, the touchscreen display (160) can display a variety of other screens as well. Additionally, the touchscreen display (160) is configured to receive user input in the form of a user contacting the touchscreen display (160) in accordance with conventional touchscreen technology. Additionally or alternatively, the sterilization cabinet (150) can include a variety of other types of user input capabilities, including, but not limited to, buttons, keypads, keyboards, mice, trackballs, and the like.

[0012] The sterilization cabinet (150) of this example also includes a processor (162), which is in communication with the sterilization module (156) and the touchscreen display (160). The processor (162) is operable to execute control algorithms to drive the sterilization module (156) according to user input. The processor (162) is also operable to execute instructions to display various screens on the touchscreen display (160) and to process instructions received from a user via the touchscreen display (160) (and / or via other user input features). The processor (162) is also in communication with various other components of the sterilization cabinet (150), and is operable to drive those components and / or process input and / or other data from those components. In view of the teachings herein, a variety of suitable components and configurations that may be used to form the processor (162) will be apparent to those of skill in the art.

[0013] Additionally, the sterilization cabinet (150) of this example also includes an identification tag reader (166) operable to read the identification tag of the biological indicator as described herein. By way of example only, the identification tag reader (166) may include an optical reader operable to read the optical identification tag of the biological indicator (e.g., bar code, QR code, etc.). Additionally or alternatively, the identification tag reader (166) may include an RFID reader operable to read the RFID identification tag of the biological indicator (e.g., bar code, QR code, etc.). In view of the teachings herein, various suitable components and configurations that may be used to form the identification tag reader (166) will be apparent to those skilled in the art. Data received through the identification tag reader (166) is processed via the processor (162).

[0014] Additionally, the example sterilization cabinet (150) also includes a memory (168) operable to store control logic and instructions executed by the processor (162) to drive components such as the sterilization module (156), the touch screen display (160), the communications module (154), and the identification tag reader (166). Additionally, the memory (168) may be used to store results relating to sterilization cycle settings, load conditioning cycle performance, sterilization cycle performance, and / or various other types of information. In light of the teachings herein, the various suitable forms that the memory (168) may take, as well as the various ways in which the memory (168) may be used, will be apparent to those skilled in the art.

[0015] Additionally, the example sterilization cabinet (150) also includes a printer (170) operable to print information, such as results related to sterilization cycle settings, load conditioning cycle performance, sterilization cycle performance, and / or various other types of information. For purposes of example only, the printer (170) may include a thermal printer, although it will be appreciated that other suitable types of printers may be used. In light of the teachings herein, the various suitable forms that the printer (170) may take, as well as the various ways in which the printer (170) may be used, will be apparent to those of ordinary skill in the art. It will also be understood that the printer (170) is merely optional and may be omitted in some embodiments.

[0016] The sterilization chamber (150) of this example further includes a vacuum source (180) and a vent valve (182). The vacuum source (180) is in fluid communication with the sterilization chamber (152) and is also in communication with the processor (162). As such, the processor (162) is operable to selectively activate the vacuum source (180) according to one or more control algorithms. When the vacuum source (180) is activated, the vacuum source (180) is operable to reduce pressure within the sterilization chamber (152), as described in more detail below. The vent valve (182) is also in fluid communication with the sterilization chamber (152). Additionally, the vent valve (182) is in communication with the processor (162) such that the processor (162) is operable to selectively activate the vent valve (182) according to one or more control algorithms. When the vent valve (182) is actuated, the vent valve (182) is operable to vent the sterilization chamber (152) to atmosphere, as will be described in further detail below. A variety of suitable components that may be used to provide the vacuum source (180) and the vent valve (182) will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0017] In addition to the above, the sterilization cabinet (150) may be constructed and operated in accordance with at least a portion of the teachings of U.S. Pat. No. 6,939,519, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,852,279, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,852,277, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,447,719, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,365,102, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,325,972, the disclosures of which are incorporated herein by reference; and / or U.S. Provisional Patent Application No. 62 / 316,722, the disclosures of which are incorporated herein by reference.

[0018] II. Exemplary Sterilization Process Overview 2 shows a high-level flow chart of an exemplary set of steps that a sterilization cabinet (150) may perform to sterilize used medical instruments, such as an endoscope. The sterilization cabinet (150) may be configured to perform one or more sterilization cycles, with different sterilization cycles being appropriate for different types and quantities of medical instruments. Thus, as an initial step, the sterilization cabinet (150) may display one or more available sterilization cycles via a touch screen display (160) and then receive a selection of a sterilization cycle from a user (block 200).

[0019] The sterilization cabinet (150) may also display instructions indicating whether a biological indicator should be used in the selected sterilization cycle and receive a biological indicator identification (block 202). Such biological identification (block 202) may be provided via the identification tag reader (166), via the touch screen display (160), or in another manner. The biological indicator may be placed in the sterilization chamber (152) of the sterilization cabinet (150) before the sterilization cycle begins and may remain in the sterilization chamber during the sterilization cycle. Thus, a user may identify a particular biological indicator (block 202) before placing the biological indicator in the sterilization chamber. The biological indicator may include a microorganism that responds to a particular sterilization cycle. Upon completion of the sterilization cycle, the biological indicator may be tested for microorganisms to provide a measure of the effectiveness of the sterilization cycle. Biological indicators are not necessarily required for all sterilization cycles and may be required based on hospital rules or local regulations.

[0020] The selection of a sterilization cycle (block 200) and the identification of biological indicators (block 202) may define one or more requirements for the configuration and placement of medical instruments within the sterilization chamber (152). Thus, once a sterilization cycle has been selected (block 200) and the biological indicators have been identified (block 202) in preparation for a sterilization cycle (204), the sterilization cabinet (150) may provide an indication via the touch screen display (160) of the proper placement of medical instruments. This indication may serve as a visual guide for the user to place the medical instruments (and possibly the biological indicators) within the sterilization chamber (152) of the sterilization cabinet (150) based on the selection of the sterilization cycle (block 200). The door of the sterilization chamber (152) may be opened to allow the user to place the medical instruments (and possibly the biological indicators) within the sterilization chamber (152) as directed.

[0021] Once the user has positioned the medical equipment within the sterilization chamber (152) based on these instructions, the user may press a start button or other button to indicate that positioning of the medical equipment is complete. In some variations, the sterilization chamber (150) is configured to automatically verify proper placement of the medical equipment. By way of example only, the sterilization chamber (150) may employ optical sensors, imaging devices, weight sensors, and / or other components to verify proper placement of the medical equipment within the sterilization chamber (152). However, it should be understood that some variations of the sterilization chamber (150) may not have the capability to automatically verify proper placement of the medical equipment within the sterilization chamber (152).

[0022] Once placement of the medical instruments has been confirmed and / or the user has otherwise prepared for the cycle (block 204), the sterilization cabinet (150) may begin a load adjustment process (block 206) that prepares the sterilization chamber (152) and the medical instruments therein for optimal sterilization during a sterilization cycle. Adjustment may include controlling and optimizing one or more characteristics of the sterilization chamber (152). For example, during load adjustment, the sterilization cabinet (150) may continuously monitor the moisture level within the sterilization chamber (152) while reducing the moisture level by, for example, circulating and dehumidifying the air within the sterilization chamber (152), creating a vacuum within the sterilization chamber (152), heating the sterilization chamber (152), and / or other methods to dehumidify the sealed chamber. This may continue until the sterilization cabinet (150) determines that an acceptable level of moisture has been reached.

[0023] As part of the load conditioning cycle (block 206), the sterilization chamber (150) may also continuously sense the temperature within the sterilization chamber (152) while heating the sterilization chamber (152), for example, by convection of heated air, conduction through the interior surfaces of the sterilization chamber (152), and / or using other techniques. This may continue until the sterilization chamber (150) determines that an acceptable internal temperature has been reached. Various conditioning operations, such as controlling temperature or humidity, may be performed in parallel or sequentially. It should also be appreciated that the load conditioning cycle (block 206) may include verifying that the sterilization chamber is sealed, verifying the contents of the sterilization chamber, verifying physical characteristics of the contents of the sterilization chamber, such as the volume of the contents, the weight of the contents, or other characteristics, and / or performing one or more conditioning steps, which may include chemical, plasma, or other types of treatments to reduce moisture, increase temperature, and / or prepare the medical instruments in the sterilization chamber (152) for the sterilization cycle (block 208).

[0024] While one or more adjustment actions have been performed as part of the load adjustment cycle (block 206), the sterilization cabinet (150) may display information via the touch screen display (160) indicating to the user a period of time until the performance of the sterilization cycle (block 208) may begin. Once all load adjustment criteria have been successfully met, the load adjustment cycle (block 206) is completed and the sterilization cycle (block 208) may then be performed. It should therefore be understood that the sterilization cabinet (150) is configured such that the sterilization cycle (block 208) does not actually begin until the load adjustment cycle (block 206) is completed. It should also be understood that the load adjustment cycle (block 206) may be omitted or modified in some variations of the operation of the sterilization cabinet (150).

[0025] As described above, the sterilization cabinet (150) may automatically and immediately begin performing a sterilization cycle (block 208) after the load adjustment cycle (block 206) is completed. The sterilization cycle (block 208) may include exposing the medical device(s) in the sterilization chamber to autoclaved sterilization gas, additional heat treatment, chemical treatment, plasma treatment, vacuum treatment, and / or other types of sterilization treatment. During the sterilization cycle (block 208), the sterilization cabinet (150) may display information via the touch screen display (160), such as the time remaining in the sterilization cycle (block 208), the current stage of the sterilization cycle (block 208) (e.g., plasma, vacuum, injection, heat, chemical treatment), and / or other information.

[0026] In some variations, the sterilization cycle (block 208) includes the exemplary sub-steps shown in FIG. 3. Specifically, the cycle may begin by applying a reduced pressure within the sterilization chamber (152) (block 310). To effect such reduced pressure, the processor (162) may activate the vacuum source (180) in accordance with a control algorithm. The processor (162) then determines whether a sufficient pressure level has been reached within the sterilization chamber (152) (block 312). By way of example only, the processor (162) may monitor data from one or more pressure sensors within the sterilization chamber (152) as part of the decision step (block 312). Alternatively, the processor (162) may simply activate the vacuum source (180) for a predetermined period of time and assume that an appropriate pressure has been achieved within the sterilization chamber (152) based on the period of time that the vacuum source (180) has been activated. Other suitable manners by which the processor (162) may determine (block 312) whether a sufficient pressure level has been achieved within the sterilization chamber (152) will be apparent to those of ordinary skill in the art in view of the teachings herein. The vacuum source (180) will remain activated until the appropriate pressure level is achieved within the sterilization chamber (152).

[0027] Once the sterilization chamber (152) reaches an appropriate pressure level (e.g., about 0.03 kPa to about 1 kPa (about 0.2 Torr to about 10 Torr)), the processor (162) then activates the sterilization module (156) to apply a sterilant into the sterilization chamber (152) (block 314). This stage of the process may be referred to as the "transfer phase." By way of example only, the sterilant may include an oxidizing agent vapor, such as hydrogen peroxide, a peroxyacid (e.g., peracetic acid, performic acid, etc.), ozone, or a mixture thereof. Additionally, the sterilant may include chlorine dioxide. Various other suitable forms that the sterilant may take are described herein, although other forms will be apparent to those of skill in the art in view of the teachings herein. It will also be appreciated that in some variations, the sterilant may be applied in various manners (block 314) based on the user's selection of the cycle (block 200) as described above. Once the sterilant has been applied to the sterilization chamber (152) (block 314), the processor (162) monitors the time to determine whether a sufficient predetermined period of time has elapsed (block 316). By way of example only, this predetermined period of time may be from a few seconds to a few minutes. Until the predetermined period of time has elapsed, the sterilization chamber (152) remains sealed at the predetermined pressure level described above, and the applied sterilant will act on the medical instruments contained within the sterilization chamber (152).

[0028] After a predetermined period of time has elapsed, the processor (162) actuates the vent valve (182) (block 318) to vent the sterilization chamber (152) to the atmosphere. In some variations, the sterilization chamber (152) is allowed to reach atmospheric pressure, while in other variations, the sterilization chamber (152) simply reaches sub-atmospheric pressure. The venting stage of the process is sometimes referred to as the "diffusion phase." In this example, the sterilization cycle is then completed after completion of the diffusion phase (block 320). In some other examples, a vacuum is again applied to the sterilization chamber (152) after completion of the diffusion phase, and then a plasma is applied to the sterilization chamber (152). The entire sterilization cycle shown in FIG. 3 (including the above-mentioned variations in which a vacuum is then applied, followed by sterilization) may be repeated one or more times after being completed once. In other words, the medical instruments may remain in the sterilization chamber (152) and undergo the entire cycle shown in FIG. 3 (including the above-mentioned variations in which a vacuum is then applied, followed by sterilization) two or more times. The number of repetitions may vary based on the cycle selection (block 200), which may be dictated by the particular type of medical instruments being sterilized in the sterilization chamber (152).

[0029] FIG. 4 illustrates an exemplary plot (400) showing the pressure within the sterilization chamber (152) during the sterilization cycle (block 208) shown in FIG. 3 and described above. As can be seen, the pressure level drops significantly and abruptly when the vacuum source (180) is activated to apply reduced pressure to the sterilization chamber (152) (block 310). The pressure level then remains substantially constant while the sterilant is applied (block 314) and for a predetermined period thereafter (block 316). The pressure level then increases significantly and abruptly when the vent valve (182) is activated (block 318) to vent the sterilization chamber (152) to the atmosphere. Thus, generally speaking, the plot (400) illustrates how the pressure within the sterilization chamber (152) toggles briefly between a single relatively high level (i.e., atmospheric pressure) and a single relatively low level (i.e., vacuum). Exemplary and alternative sterilization cycles are described in further detail below with reference to FIGS. 5-6.

[0030] Upon completion of the sterilization cycle (block 208), the sterilization cabinet (150) may cycle (block 210) the results of the sterilization cycle (block 208). If the sterilization cycle (block 208) is cancelled or cannot be completed, for example due to an error or by user action, the sterilization cabinet (150) may still be sealed and may display, via the touchscreen display (160), a sterilization cycle cancelled message, as well as various details relating to the sterilization cycle, such as the date, time, configuration, elapsed time, sterilization cycle operator, the stage at which the sterilization cycle failed, and other information that may be used to identify the reason for the sterilization cycle. Upon successful completion of the sterilization cycle (block 208), the sterilization cabinet (150) may display, via the touchscreen display (160), a notification that the sterilization cycle (block 208) was successfully completed. Additionally, the sterilization cabinet (150) may display information such as a sterilization cycle identifier, sterilization cycle type, start time, duration, operator, and other information (666).

[0031] In addition to the above, the sterilization cabinet (150) may be configured to perform a sterilization process in accordance with at least some of the teachings of U.S. Pat. No. 6,939,519, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,852,279, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,852,277, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,447,719, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,365,102, the disclosures of which are incorporated herein by reference; U.S. Pat. No. 6,325,972, the disclosures of which are incorporated herein by reference; and / or U.S. Provisional Patent Application No. 62 / 316,722, the disclosures of which are incorporated herein by reference.

[0032] III. EXEMPLARY AND ALTERNATIVE STERILIZATION CYCLES As noted above, some variations of the sterilization chamber (150) may make it difficult to effectively sterilize medical instruments, such as flexible endoscopes, having relatively long and narrow lumens. For example, some conventional sterilization chambers may be capable of sterilizing lumens less than or equal to about 875 mm and having lumen diameters of about 1 mm or greater. It may therefore be desirable to provide a modified sterilization cycle (block 208) that further facilitates effective sterilization of medical instruments having one or more relatively long and narrow lumens. A merely illustrative example of such a modified sterilization cycle is described in further detail below. By way of example only, a medical instrument having one or more relatively long and narrow lumens may include a gastrointestinal endoscope having a lumen that is about 1 m to about 3 m long and has a diameter of about 0.5 mm to about 2.0 mm. Nevertheless, it should be understood that the process described below may also be performed on an endoscope having a length of at least about 500 mm or at least about 800 mm and a lumen that has a diameter of less than about 6.0 mm.

[0033] FIG. 5 illustrates an exemplary alternative set of sub-steps that may be performed to provide a sterilization cycle (block 208) for the sterilization chamber (150). Specifically, the cycle may begin by applying a reduced pressure within the sterilization chamber (152) (block 510). To effect such reduced pressure, the processor (162) may activate the vacuum source (180) in accordance with a control algorithm. The processor (162) then determines whether a sufficient pressure level has been reached within the sterilization chamber (152) (block 512). By way of example only, the processor (162) may monitor data from one or more pressure sensors within the sterilization chamber (152) as part of the decision step (block 512). Alternatively, the processor (162) may simply activate the vacuum source (180) for a predetermined period of time and assume that an appropriate pressure has been reached in the sterilization chamber (152) based on the period for which the vacuum source (180) has been activated. Other suitable manners by which the processor (162) may determine (block 512) whether a sufficient pressure level has been achieved within the sterilization chamber (152) will be apparent to those of ordinary skill in the art in view of the teachings herein. The vacuum source (180) will remain activated until the appropriate pressure level is achieved within the sterilization chamber (152).

[0034] Once the sterilization chamber (152) reaches an appropriate pressure level (e.g., about 0.03 kPa to about 1 kPa (about 0.2 Torr to about 10 Torr)), the processor (162) then activates the sterilization module (156) to apply a sterilant within the sterilization chamber (152) (block 514). By way of example only, the sterilant may include an oxidizing agent vapor, such as hydrogen peroxide, a peroxyacid (e.g., peracetic acid, performic acid, etc.), ozone, or a mixture thereof. Additionally, the sterilant may include chlorine dioxide or nitrogen dioxide. Various other suitable forms that the sterilant may take are described herein, although other forms will be apparent to those of skill in the art in view of the teachings herein. It will also be appreciated that in some variations, the sterilant may be applied in various manners (block 514) based on the user's selection of the cycle (block 200) as described above. Once the sterilant has been applied to the sterilization chamber (152) (block 514), the processor (162) monitors the time to determine whether a sufficient predetermined period of time has elapsed (block 516). By way of example only, this predetermined period of time may be from a few seconds to a few minutes. Until the predetermined period of time has elapsed, the sterilization chamber (152) remains sealed at the predetermined pressure level described above, and the applied sterilant acts on the medical instruments contained within the sterilization chamber (152). This stage of the process is sometimes referred to as the "transfer phase."

[0035] After the predetermined period of time has elapsed, the processor (162) actuates the vent valve (182) (block 518) to vent the sterilization chamber (152) to atmosphere. With the sterilization chamber (152) vented to atmosphere (block 518), the processor (162) monitors time (block 520) to determine whether a sufficient predetermined venting (block 518) period has elapsed. The sterilization chamber (152) remains vented until the predetermined venting (block 518) period has elapsed. After the predetermined venting (block 518) period has elapsed, the processor (162) determines whether the sterilization cycle is complete (block 522). An example of how this determination (block 522) may be made will be described in more detail below. It should be understood that in this example, the predetermined venting (block 518) period may be very brief. By way of example only, the predetermined venting (block 518) period may be approximately 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds, or any other suitable period.

[0036] If processor (612) determines (block 522) that the sterilization cycle is complete, then the sterilization cycle is in fact complete (block 528). However, if processor (162) determines (block 522) that the sterilization cycle is not yet complete, processor (162) closes vent valve (182) and seals sterilization chamber (152) at a pressure level that is still below atmospheric pressure (block 524). As noted above, the venting (block 518) period is very short in this example, and therefore, the act of sealing (block 524) can occur very quickly after venting (block 518) is initiated, assuming that the sealing (block 524) is appropriate as determined by the determinations (blocks 520, 522).

[0037] The sterilization chamber (152) will remain sealed for a certain period of time (block 524). Specifically, with the sterilization chamber (152) sealed (block 524), the processor (162) monitors time to determine whether a sufficient predetermined sealing (block 524) period has elapsed (block 526). The sterilization chamber (152) will remain sealed until the predetermined sealing (block 524) period has elapsed. After the predetermined sealing (block 524) period has elapsed, the processor (162) again activates the vent valve (182) (block 518) to vent the sterilization chamber (152) to the atmosphere. By way of example only, the predetermined sealing period may be between about 5 seconds and 5 minutes, or, more specifically, between about 10 seconds and about 2 minutes, or, more specifically, between about 20 seconds and about 2 minutes.

[0038] At this point, the process continues through the steps described above (blocks 518, 520, 522, 524, 526), ​​whereby the process provides a series of venting (block 518) and sealing (block 524) of the sterilization chamber (152) to increase the pressure within the sterilization chamber (152) in a stepwise manner until the sterilization chamber (152) reaches atmospheric or a predetermined subatmospheric pressure. Again, each venting (block 518) step is very brief in this example, so that the pressure within the sterilization chamber (152) is maintained at a subatmospheric level for the duration of the sealing (block 524) operation (e.g., for a period of about a few seconds or minutes). By way of example only, each step of venting (block 518) may result in a respective increase in pressure within the sterilization chamber (152) by about 1 kPa to about 13 kPa (about 10 Torr to about 100 Torr), or more specifically, about 1 kPa to about 4 kPa (about 10 Torr to about 30 Torr), until the final step of venting (block 518) is achieved. Other suitable incremental pressure increase values ​​will be apparent to those of skill in the art in view of the teachings herein. As the sterilization chamber (150) reaches the end of the process, the vent valve (182) is still open such that the sterilization chamber (152) still remains at atmospheric pressure. This final venting step (block 518) of the process is sometimes referred to as the "diffusion phase."

[0039] In some variations, the venting period (block 520) and / or the sealing period (block 526) may vary. For example, the venting period (block 520) and / or the sealing period (block 526) may differ based on the cycle selection (block 200), which may depend on the particular type of medical instruments being sterilized in the sterilization chamber (152). Additionally or alternatively, the venting period (block 520) and / or the sealing period (block 526) may vary based on where the sterilization cycle is located in the process (i.e., which venting (block 518) iteration and / or which sealing (block 524) iteration). Various suitable manners in which the venting period (block 520) and / or the sealing period (block 526) may vary, as well as various reasons why such periods may vary, will be apparent to one of ordinary skill in the art in view of the teachings herein.

[0040] Figure 6 illustrates an exemplary plot (600) showing the pressure within the sterilization chamber (152) during the sterilization cycle (block 208) shown in Figure 5 and described above. As can be seen, the pressure level drops significantly and sharply when the vacuum source (180) is activated to apply reduced pressure to the sterilization chamber (152) (block 510). The pressure level then remains substantially constant while the sterilant is applied (block 514) and for a predetermined period thereafter (block 516). The pressure level then increases slightly when the vent valve (182) is activated (block 518) to vent the sterilization chamber (152) to the atmosphere, but remains at a level below atmospheric pressure when the sterilization chamber (152) is sealed (block 524). The pressure level again increases slightly when the vent valve (182) is again actuated (block 518) to vent the sterilization chamber (152) to atmosphere, but still remains at a sub-atmospheric level when the sterilization chamber (152) is resealed (block 524).

[0041] In the example shown in FIG. 6, the cycle results in four repetitions of short venting (block 518), followed by four repetitions of sealing (block 524), before finally venting completely to atmosphere (block 518). Thus, generally speaking, plot (600) illustrates how the pressure within the sterilization chamber (152) is increased in a stepwise fashion from a substantially vacuum state to atmospheric pressure. Although FIG. 6 illustrates four repetitions of short venting and short sealing, other processes may use any other suitable number of repetitions of short venting and short sealing. By way of example only, each variation may result in from 2 repetitions of short venting and short sealing to 100 repetitions of short venting and short sealing, or more specifically, from 2 repetitions of short venting and short sealing to 10 repetitions of short venting and short sealing, or more specifically, from 3 repetitions of short venting and short sealing to 7 repetitions of short venting and short sealing.

[0042] In some instances, the process illustrated in Figures 5-6 may result in more effective sterilization of some medical instruments as compared to sterilization of the same medical instruments using the process illustrated in Figures 3-4. Specifically, without being limited by theory, the staged venting of the sterilization chamber (152) may result in agitation of the contents of the sterilization chamber (152), which may assist in forcing the sterilant into the lumens and / or other interior spaces within the medical instruments. Additionally, while also not being limited by theory, the staged venting of the sterilization chamber (152), which may be associated with the process illustrated in Figures 5-6, may result in convective mass transfer of sterilant vapor molecules inside the lumens and / or other interior spaces within the medical instruments as compared to simple diffusive mass transfer of the vapor associated with the process illustrated in Figures 3-4. Thus, when the sterilization cabinet (150) performs the process shown in Figures 5-6, the sterilization cabinet (150) can sterilize relatively long gastrointestinal endoscopes (e.g., up to about 3 m in length and with lumens having diameters of up to about 1 mm) as compared to a sterilization cabinet (150) performing the process shown in Figures 3-4, which is unable to sterilize the long, narrow lumens of the same type of gastrointestinal endoscope.

[0043] It should also be understood that the entire cycle shown in Figures 5-6, once completed, may be repeated one or more times. In other words, the medical instruments may remain within the sterilization chamber (152) and undergo two or more iterations of the entire cycle shown in Figures 5-6. The number of iterations may vary based on the cycle selection (block 200), which may be dictated by the particular type of medical instruments being sterilized within the sterilization chamber (152).

[0044] By way of example only, an endoscope having a 3 m long lumen may be placed in the sterilization chamber (152). A vacuum may be applied (block 510) to achieve a pressure level of about 0.60 kPa (about 4.5 Torr) within the sterilization chamber (152). A sterilant (e.g., about 1 mL of hydrogen peroxide vapor at a concentration of 59%) may then be applied (block 514) resulting in a transfer phase lasting about 30 seconds. The sterilization chamber (152) may then be briefly vented (block 518) to achieve a pressure level of about 1.83 kPa (about 13.7 Torr), and the sterilization chamber (152) may then be sealed (block 524). The sterilization chamber (152) may be maintained at about 1.83 kPa (about 13.7 Torr) for about 150 seconds. The sterilization chamber (152) may then be re-vented (block 518) for a short period of time to achieve a pressure of about 4.01 kPa (about 30.1 Torr), and then the sterilization chamber (152) may be resealed (block 524). The sterilization chamber (152) may be maintained at about 4.01 kPa (about 30.1 Torr) for about 200 seconds. The sterilization chamber (152) may then be re-vented (block 518) for a short period of time to achieve a pressure of about 6.28 kPa (about 47.1 Torr), and then the sterilization chamber (152) may be resealed (block 524). The sterilization chamber (152) may then be maintained at about 6.28 kPa (about 47.1 Torr) for about 190 seconds. The sterilization chamber (152) may then be re-vented (block 518) for a short period of time to achieve a pressure level of about 101 Pa (about 760 Torr) (i.e., atmospheric pressure), thereby resulting in a diffusion phase. Of course, the above are merely illustrative examples.

[0045] In some variations, additional sterilant is introduced into the sterilization chamber (152) during one or more of the staged venting (block 518) operations before the final step of venting (block 518) is accomplished.

[0046] Also, in some variations, a pre-plasma may be applied in the sterilization cycle (block 208) to heat the medical instruments stored within the sterilization chamber (152). By way of example only, a plasma may be applied between the application of reduced pressure (block 510) and the application of sterilant (block 514). Additionally or alternatively, a post-plasma may be applied at the end of the sterilization cycle (block 208) to decompose residual sterilant that may be absorbed onto surfaces of the medical instruments stored within the sterilization chamber (152). It should be understood that a reduced pressure must first be applied to the sterilization chamber (152) before post-plasma can be applied.

[0047] As described above, the sterilant is applied in the form of a vapor within the sterilization chamber (152) (block 514). By way of example only, the sterilization module (156) may comprise a combination evaporator and condenser. The evaporator may include a chamber that receives a sterilant solution of a particular concentration (e.g., a liquid hydrogen peroxide solution of a concentration of about 59% nominal, or about 58% to about 59.6%), where the sterilant solution changes from a liquid phase to a gas phase. The condenser may result in condensation of the sterilant solution, the concentration of which may thus be increased by the removal of water vapor (e.g., from about 59% nominal to between about 83% to about 95% nominal). Alternatively, any other suitable method and components may be used to apply the sterilant in the form of a vapor within the sterilization chamber (152). In any event, to supplement the application of the sterilant in the form of steam, the sterilant may also be applied inside lumens and / or other interior spaces within the medical device and / or to the exterior of the medical device before the medical device is placed into the sterilization chamber (152). In such variations, the sterilant may evaporate while the reduced pressure is applied (block 510) and even after the reduced pressure is applied (block 510) and may provide a higher concentration of sterilant to a smaller area of ​​penetration of the medical device, thereby further facilitating effective sterilization.

[0048] By way of example only, the process shown in FIG. 5 may be carried out at a temperature such that the walls of the sterilization chamber (152) are between about 30° C. and about 56° C., more specifically about 47° C. and about 56° C., and even more specifically about 50° C., and the temperature of the medical instruments within the sterilization chamber (152) is between about 5° C.-10° C. and about 40° C.-55° C.

[0049] Although the above examples are described in the context of sterilizing medical instruments, and in particular endoscopes, it should be understood that the teachings herein may also be readily applied in the context of sterilizing a variety of other types of articles. These teachings are not limited to endoscopes or other medical instruments. Other suitable articles that may be sterilized in accordance with the teachings herein will be apparent to those of skill in the art.

[0050] IV. Example Combinations The following examples relate to various non-exhaustive methods in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to limit the scope of any claims that may be presented at any time in this application or in a later application of this application. No disclaimer is intended. The following examples are provided for illustrative purposes only. It is contemplated that the various teachings herein may be configured and applied in many other ways. It is also contemplated that in some variations, certain elements referred to in the following examples may be omitted. Thus, none of the aspects or elements referred to below should be considered as critical unless expressly indicated to be so at a later date by the inventor or by the inventor's successor in interest. If a claim including additional elements other than those referred to below is presented in this application or in a later application related to this application, these additional elements should not be presumed to have been added for any reason related to patentability. EXAMPLES

[0051] Example 1 1. A method of sterilizing an article, comprising: (a) receiving the article in a sterilization chamber; (b) applying a vacuum to the sterilization chamber to reduce a pressure in the sterilization chamber to a first pressure, the first pressure being less than atmospheric pressure; (c) introducing a sterilant into the sterilization chamber; (d) maintaining the first pressure in the sterilization chamber for a first period of time; (e) venting the sterilization chamber to increase a pressure in the sterilization chamber to a second pressure, the second pressure being less than atmospheric pressure; (f) maintaining the second pressure in the sterilization chamber for a second period of time; (g) venting the sterilization chamber to increase a pressure in the sterilization chamber to a third pressure; and (h) maintaining a third pressure in the sterilization chamber for a third period of time.

[0052] Example 2 The method of example 1, wherein the article comprises a medical device.

[0053] Example 3 The method of example 2, wherein the medical device comprises an endoscope.

[0054] Example 4 The method of example 3, wherein the endoscope defines a lumen.

[0055] Example 5 The method of example 4, wherein the lumen has a length of at least 800 mm and an inner diameter of less than 6 mm.

[0056] Example 6 The method of any one of Examples 1 to 5, wherein the second period of time is longer than the first period of time.

[0057] Example 7 The method according to any one of the preceding embodiments, wherein the first period of time is from about 5 seconds to about 5 minutes.

[0058] Example 8 The method according to any one of Examples 1 to 7, wherein the first period of time is from about 20 seconds to about 2 minutes.

[0059] Example 9 9. The method of any one of claims 1-8, wherein the second pressure is between about 10 Torr (1 kPa) higher than the first pressure and about 100 Torr (13 kPa) higher than the first pressure.

[0060] Example 10 The method of any one of Examples 1-9, wherein the second pressure is between about 1 kPa (about 10 Torr) higher than the first pressure and about 4 kPa (about 30 Torr) higher than the first pressure.

[0061] Example 11 The method of any one of claims 1-10, wherein the third pressure is between about 10 Torr (1 kPa) higher than the second pressure and about 100 Torr (13 kPa) higher than the second pressure.

[0062] Example 12 The method of any one of embodiments 1-11, wherein the third pressure is about 101 kPa (about 760 Torr).

[0063] Example 13 The method of any one of Examples 1 to 12, further comprising applying a plasma to the sterilization chamber.

[0064] Example 14 14. The method of example 13, wherein the act of applying plasma includes applying plasma to the sterilization chamber between the acts of applying a reduced pressure to the sterilization chamber and introducing a sterilant to the sterilization chamber.

[0065] Example 15 15. The method of example 13 or 14, wherein the act of applying the plasma includes (i) depressurizing the sterilization chamber after maintaining a third pressure within the sterilization chamber, and (ii) then applying the plasma.

[0066] (Example 16) 16. The method of any one of claims 1-15, further comprising introducing additional sterilant into the sterilization chamber during the operation of venting the sterilization chamber to increase the pressure in the sterilization chamber to a second pressure.

[0067] (Example 17) The method of any one of Examples 1-16, further comprising applying a sterilant to one or more interior spaces within the article prior to receiving the article in the sterilization chamber.

[0068] (Example 18) The method of any one of Examples 1-17, wherein the sterilizing agent is selected from the group consisting of hydrogen peroxide, peroxyacid, ozone, or mixtures thereof.

[0069] (Example 19) 1. A method of sterilizing articles, comprising: (a) receiving articles in a sterilization chamber; (b) applying a vacuum to the sterilization chamber to reduce the pressure in the sterilization chamber to below atmospheric pressure; (c) introducing a sterilant into the sterilization chamber; (d) venting the sterilization chamber to incrementally increase the pressure in the sterilization chamber without reaching atmospheric pressure; (e) maintaining the incrementally increased pressure in the sterilization chamber for a period of time; (f) repeating steps (d) through (e) at least once; and (g) venting the sterilization chamber to increase the pressure in the sterilization chamber to atmospheric pressure.

[0070] (Example 20) 1. An apparatus comprising: (a) a sterilization chamber configured to receive a medical instrument; (b) a vacuum source in fluid communication with the sterilization chamber; (c) a sterilant application module in fluid communication with the sterilization chamber; (d) a vent valve in fluid communication with the sterilization chamber, the vent valve further in fluid communication with the atmosphere such that the vent valve is operable to selectively open and close a vent path between the sterilization chamber and the atmosphere; and (e) a control module in communication with the vacuum source, further in communication with the sterilant application module and further in communication with the vent valve, the control module including control logic configured to execute a sterilization algorithm, the control logic configured to (i) activate the vacuum source to apply a reduced pressure to the sterilization chamber, (ii) activate the sterilant application module to apply a sterilant to the sterilization chamber, and (iii) selectively activate the vent valve to increase pressure within the sterilization chamber in a step-wise and incremental manner towards atmospheric pressure.

[0071] V.Other It should be recognized that any patent, publication, or other disclosure referred to herein as being incorporated by reference, in whole or in part, is incorporated herein only to the extent that the incorporated content does not contradict existing definitions, opinions, or other disclosure content set forth in this disclosure. As such, and to the extent necessary, the disclosure content explicitly set forth herein shall take precedence over any conflicting statements incorporated herein by reference. Any document, or portion thereof, that is incorporated herein by reference but that contradicts existing definitions, descriptions, or other disclosure documents set forth herein shall be incorporated only to the extent that no contradiction occurs between the incorporated document and the existing disclosure content.

[0072] Although various embodiments of the present invention have been shown and described above, further adaptations of the methods and systems described herein can be realized by those skilled in the art through appropriate modifications without departing from the scope of the present invention. Some of such possible modifications have been described, but other modifications will be apparent to those skilled in the art. For example, the examples, embodiments, shapes, materials, dimensions, ratios, steps, etc. discussed above are illustrative and not essential. Therefore, the scope of the present invention should be considered in terms of the following claims and should not be understood to be limited to the details of structure and operation shown and described in the specification and drawings.

[0073] [Embodiment] (1) A method for sterilizing an article, comprising the steps of: (a) receiving the article within a sterilization chamber; (b) applying a vacuum to the sterilization chamber to reduce pressure within the sterilization chamber to a first pressure, the first pressure being less than atmospheric pressure; and (c) introducing a sterilant into the sterilization chamber; (d) maintaining the first pressure in the sterilization chamber for a first period of time; (e) venting the sterilization chamber to increase the pressure within the sterilization chamber to a second pressure, the second pressure being less than atmospheric pressure; and (f) maintaining the second pressure in the sterilization chamber for a second period of time; (g) venting the sterilization chamber to increase the pressure within the sterilization chamber to a third pressure; (h) maintaining the third pressure in the sterilization chamber for a third period of time. (2) The method of claim 1, wherein the article comprises a medical device. (3) The method of embodiment 2, wherein the medical device comprises an endoscope. (4) The method of embodiment 3, wherein the endoscope defines a lumen. (5) The method of embodiment 4, wherein the lumen has a length of at least 800 mm and an inner diameter of less than 6 mm.

[0074] (6) The method of embodiment 1, wherein the second period of time is longer than the first period of time. (7) The method of embodiment 1, wherein the first period of time is from about 5 seconds to about 5 minutes. (8) The method of embodiment 1, wherein the first period of time is from about 20 seconds to about 2 minutes. 9. The method of claim 1, wherein the second pressure is between about 10 Torr (1 kPa) higher than the first pressure and about 100 Torr (13 kPa) higher than the first pressure. 10. The method of claim 1, wherein the second pressure is between about 10 Torr (1 kPa) higher than the first pressure and about 30 Torr (4 kPa) higher than the first pressure.

[0075] 11. The method of claim 1, wherein the third pressure is between about 10 Torr (1 kPa) higher than the second pressure and about 100 Torr (13 kPa) higher than the second pressure. 12. The method of claim 1, wherein the third pressure is about 101 kPa (about 760 Torr). 13. The method of claim 1, further comprising applying a plasma to the sterilization chamber. (14) The method of claim 13, wherein the act of applying plasma includes applying plasma to the sterilization chamber between the acts of applying the reduced pressure to the sterilization chamber and introducing the sterilant to the sterilization chamber. (15) The method of claim 13, wherein the act of applying the plasma includes (i) depressurizing the sterilization chamber after maintaining the third pressure in the sterilization chamber, and then (ii) applying a plasma.

[0076] 16. The method of claim 1, further comprising introducing additional sterilant into the sterilization chamber during the operation of venting the sterilization chamber to increase the pressure within the sterilization chamber to the second pressure. 17. The method of claim 1, further comprising applying a sterilant to one or more interior spaces within the article prior to receiving the article in the sterilization chamber. 18. The method of claim 1, wherein the sterilant is selected from the group consisting of hydrogen peroxide, peroxyacid, ozone, or a mixture thereof. (19) A method for sterilizing an article, comprising the steps of: (a) receiving the article within a sterilization chamber; (b) applying a vacuum to the sterilization chamber to reduce the pressure within the sterilization chamber to less than atmospheric pressure; (c) introducing a sterilant into the sterilization chamber; (d) venting the sterilization chamber to incrementally increase pressure within the chamber without reaching atmospheric pressure; (e) maintaining the incrementally increased pressure within the sterilization chamber for a period of time; (f) repeating steps (d) through (e) at least once; and (g) venting the sterilization chamber to increase the pressure within the sterilization chamber to atmospheric pressure. (20) An apparatus comprising: (a) a sterilization chamber configured to receive medical devices; (b) a vacuum source in fluid communication with the sterilization chamber; (c) a sterilant application module in fluid communication with the sterilization chamber; (d) a vent valve in fluid communication with the sterilization chamber, the vent valve further in fluid communication with the atmosphere such that the vent valve is operable to selectively open and close a vent path between the sterilization chamber and the atmosphere; (e) a control module in communication with the vacuum source, further in communication with the sterilant application module and further in communication with the vent valve, the control module including control logic configured to execute a sterilization algorithm, the control logic comprising: (i) activating the vacuum source to apply a reduced pressure to the sterilization chamber; (ii) operating the sterilant application module to apply a sterilant to the sterilization chamber; (iii) a control module configured to selectively actuate the vent valve to incrementally increase pressure within the sterilization chamber toward atmospheric pressure.

Claims

1. An apparatus comprising: (a) a sterilization chamber configured to receive a medical instrument; (b) a vacuum source in fluid communication with the sterilization chamber; (c) a sterilant application module in fluid communication with the sterilization chamber; (d) a vent valve in fluid communication with the sterilization chamber and an atmosphere outside the sterilization chamber, the vent valve operable to selectively open and close a vent path between the sterilization chamber and the atmosphere; (e) a control module in communication with the vacuum source, the sterilant application module, and the vent valve, the control module including control logic configured to execute a sterilization algorithm, the control logic comprising: (i) activating the vacuum source to reduce pressure in the sterilization chamber to a first pressure less than 100 Torr; (ii) activating the sterilant application module to apply a sterilant to the sterilization chamber when the pressure in the sterilization chamber reaches the first pressure; (iii) actuating the vent valve to increase the pressure within the sterilization chamber to a second pressure greater than the first pressure but less than 100 Torr after a predetermined period of time has elapsed after application of the sterilant to the sterilization chamber; (iv) a control module configured to operate the vent valve to increase the pressure in the sterilization chamber to a third pressure, the third pressure being greater than the second pressure, after maintaining the pressure in the sterilization chamber at the second pressure for a predetermined period of time.

2. 1. A system comprising: An apparatus according to claim 1; The medical device; Including, the system.

3. The system of claim 2 , wherein the medical instrument comprises an endoscope.

4. The system of claim 2 , wherein the medical device comprises a plurality of endoscopes.

5. 10. The apparatus of claim 1, further comprising a door for opening and closing said sterilization chamber in response to actuation of a kick plate.

6. 10. The apparatus of claim 1, wherein the sterilant application module is configured to receive a replaceable sterilant cartridge containing a quantity of sterilant.

7. The device of claim 1 , further comprising a touch screen display configured to accept user input.

8. The device of claim 7 , wherein the touch screen display is operable to render a variety of user interface display screens.

9. 8. The apparatus of claim 7, wherein the control module is in communication with the sterilant application module and the touch screen display and is operable to execute a control algorithm to drive the sterilant application module in accordance with the user input.

10. The apparatus of claim 1 , further comprising an identification tag reader operable to read an identification tag of the biological indicator.

11. The apparatus of claim 10 , wherein the identification tag reader comprises an optical reader operable to read an optical identification tag of a biological indicator.

12. The apparatus of claim 10 , wherein the identification tag reader comprises an MD reader operable to read an RFID identification tag of a biological indicator.

13. The apparatus of claim 10 , wherein data obtained via the identification tag reader is processed via the control module.

14. 11. The apparatus of claim 10, further comprising a memory operable to store control logic and instructions executed by the control module to drive components such as the sterilant application module, the communications module, and the identification tag reader.

15. 15. The apparatus of claim 14, wherein the memory is used to store results related to sterilization cycle set-up, load adjustment cycle performance, and / or sterilization cycle performance.

16. 10. The apparatus of claim 1, further comprising an output device operable to print information such as sterilization cycle set-up, load adjustment cycle performance, and / or results related to sterilization cycle performance.

17. The apparatus of claim 16 , wherein the output device is a printer.

18. The apparatus of claim 1, wherein the second pressure is between 1 kPa (10 Torr) higher than the first pressure and 13 kPa (100 Torr) higher than the first pressure.

19. The apparatus of claim 1, wherein the third pressure is between 1 kPa (10 Torr) higher than the second pressure and 13 kPa (100 Torr) higher than the second pressure.

20. The apparatus of claim 1, wherein the third pressure is 101 kPa (760 Torr).

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