Biological indicators for use with liquid sterilants

Abstract

A biological indicator (100) for use in a liquid chemical decontamination system is disclosed. The biological indicator may include a housing (102) and a cap (106) coupled to the housing. The cap may include a liquid chamber and at least two ports. One of the ports may be connected to a liquid passage in the cap, and a liquid, such as a liquid chemical decontamination agent, may be introduced and removed from the biological indicator via the port.

Description

Disclosure Contents

[0001] [Field] The subject matter disclosed herein relates to biological indicators, particularly biological indicators suitable for use in liquid chemical decontamination systems and procedures for disinfection or sterilization.

[0002] 〔background〕 Certain instruments, such as medical instruments, must be reprocessed, i.e., decontaminated, between medical procedures in which they are used to avoid causing infection or disease to the subject. Two decontamination methods relevant to the subject matter disclosed herein include disinfection and liquid chemical sterilization. Either type of procedure may include removing foreign matter from the endoscope, cleaning the endoscope, introducing a disinfectant solution or liquid chemical sterilant into the endoscope, rinsing the endoscope, and drying the endoscope.

[0003] A decontamination indicator is a device that can be placed alongside or in close proximity to a medical device being subjected to a decontamination procedure, and the decontamination indicator is subjected to the same decontamination cycle as the medical device. For example, a biological indicator having a predetermined amount of microorganisms with known resistance to the sterilant can be placed in a sterilization chamber alongside the medical device and subjected to a sterilization cycle. After the sterilization procedure is completed, the microorganisms in the biological indicator can be cultured to determine whether any of the microorganisms survive.

[0004] Biological indicators often include a housing containing a quantity of microorganisms and a source of growth medium within a fragile container located near the microorganisms. After sterilization, the fragile container is broken to release the growth medium, allowing the surviving microorganisms to be cultured in place. The indicator can then be incubated at an elevated temperature, typically about 50°C to 60°C, to promote outgrowth of the surviving microorganisms.

[0005] Fragile containers, such as ampoules, that contain liquid growth media are often made from glass. The glass must be sturdy enough to avoid breakage during transport, for example, from the biological indicator manufacturer to a healthcare provider. However, this robustness corresponds to the significant force required to break the ampoules at the desired time by healthcare personnel. Therefore, some manufacturers provide ampoules with activation devices to assist hospital personnel in breaking them.

[0006] [Disclosure Summary] A biological indicator for use in a liquid chemical decontamination system is disclosed. The biological indicator may include a housing defining a longitudinal axis and having a first port. A cap may be coupled to the housing. The first portion of the cap may be disposed outside the housing, and the second portion of the cap may be disposed at least partially inside the housing. The second portion of the cap may include a liquid chamber including the second port and containing a growth medium. The second port may be disposed within the housing around the longitudinal axis of the housing. A seal may cover the second port and define a lower boundary of the liquid chamber. Furthermore, the second portion of the cap may include a sidewall including a rounded portion and a flat portion, the sidewall of the second portion defining a lateral boundary of the liquid chamber.

[0007] The cap may also include a third port and a liquid passageway extending through a space disposed between a sidewall of the second portion of the cap, e.g., a flat portion thereof, and the inner surface of the housing, such that a liquid, such as a liquid chemical decontaminant, may be introduced to and removed from the biological indicator via the third port.

[0008] The biological indicator may also include an insert disposed within the housing. The insert may have a tip portion, e.g., a spike, disposed along the longitudinal axis for piercing the seal. Thus, the ampoule containing the growth medium is not disposed within the housing.

[0009] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter described herein, it is believed that this subject matter will be better understood from the following description of certain specific embodiments taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements. [Brief explanation of the drawings]

[0010] [Figure 1] 1 depicts a front view of a biological indicator. [Figure 2] 1 depicts a side view of a biological indicator. [Figure 3] 1 depicts a perspective view of a biological indicator. [Figure 4] 1 depicts an exploded view of a biological indicator. [Figure 5] 5 depicts a cross-sectional view of the cap of the biological indicator taken along line 5-5 of FIG. 4.

[0011] [Mode for Carrying Out the Invention] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates, by way of example, the principles of the invention, and not by way of limitation. This description will clearly enable any person skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently contemplated as the best mode of carrying out the invention.

[0012] As used herein, the term "about" or "approximately" in connection with any numerical value or range indicates a reasonable tolerance that enables a portion or collection of components to function for its intended purpose, as described herein. More specifically, "about" or "approximately" can refer to a range of values ​​of ±10% of the recited value; for example, "about 90%" can refer to a range of values ​​of 81% to 99%. Furthermore, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and are not intended to limit the systems or methods to use in humans, although use of the invention in human patients is a preferred embodiment.

[0013] Commercially available biological indicators are typically used in sterilization procedures utilizing gaseous sterilants, such as ethylene oxide and hydrogen peroxide. Such procedures often involve positioning a medical device alongside a sterilization indicator in a vacuum chamber of a sterilization system. After a vacuum (e.g., less than 5 Torr) is pulled in the chamber, a gaseous sterilant can be introduced into the chamber, which increases the pressure within the chamber and causes the gaseous sterilant to enter the biological indicator. The gaseous sterilant is then removed from the biological indicator and the chamber by pulling a vacuum, venting the chamber, or both.

[0014] A biological indicator suitable for use in decontamination procedures utilizing a liquid chemical decontaminant is disclosed. Such decontamination procedures may include disinfection procedures utilizing a liquid chemical disinfectant, such as a solution containing ortho-phthalaldehyde, and sterilization procedures utilizing a liquid chemical sterilant, such as a solution containing peracetic acid. Thus, ortho-phthalaldehyde solutions and peracetic acid solutions can be considered examples of liquid chemical decontaminants or decontaminant solutions. During the decontamination procedure, and after the instruments and biological indicators have been exposed to the liquid decontaminant for an appropriate period of time, the liquid decontaminant must be removed from the instruments and biological indicators. There are various reasons why the liquid decontaminant must be removed from the biological indicator. For example, removal helps to avoid injury to medical personnel, which may result from skin contact with the decontaminant. Removal of the decontaminant also allows for accurate assessment of microbial growth in the biological indicator after the decontamination procedure has concluded.

[0015] 1-4 depict a biological indicator 100 suitable for use in decontamination procedures utilizing a liquid decontamination agent. Biological indicator 100 includes a housing 102 defining a longitudinal axis 104 of biological indicator 100, a cap 106, an insert 108, and a source of microorganisms or active enzymes, such as a carrier 110.

[0016] The housing 102 may have an elongated cylindrical form and may include a first port 112, an outer surface 114, and an inner surface 116. The cap 106 may be coupled to the housing 102, the cap 106 covering the first port 112.

[0017] 5, the cap 106 can include a first portion 118 and a second portion 120, which define an annular recess 140 therebetween. The upper portion of the housing 102, including the first port 112, can be disposed within the recess 140, with the cap 106 covering the first port 112. Thus, the inner surface 142 of the first portion 118 can contact the outer surface 114 of the housing 102, thereby connecting the housing 102 and the cap 106 via a friction fit. For example, the inner surface 142 and the outer surface 114 can each have a diameter of approximately 10 mm to 15 mm, with the diameter of the inner surface 142 being slightly smaller than the diameter of the outer surface 114, e.g., approximately 0.1 mm and approximately 2 mm smaller, respectively. For example, the inner surface 142 can have a diameter of approximately 12.5 mm, and the outer surface 114 can have a diameter of approximately 12.6 mm.

[0018] In particular, the inventors discovered that biological indicator 100 lacks an ampoule containing growth medium, which prevents liquids (e.g., decontaminants, neutralizing agents) from being introduced into and removed from housing 102. Accordingly, the inventors designed biological indicator 100 such that second portion 120 of cap 106 can include a liquid chamber 122 containing growth medium 124. Liquid chamber 122 can include a second port 126 covered by a seal 128, which defines a lower boundary 130 of liquid chamber 122. When cap 106 is coupled to housing 102, second portion 120 is disposed at least partially inside housing 102, and seal 128 and lower boundary 130 of liquid chamber 122 are disposed inside housing 102. Second portion 120 can also include a sidewall 134 that forms a lateral boundary 146 of liquid chamber 122. The sidewall 134 may include a rounded portion 136 and a flat portion 138. Thus, the recess 140 between the first portion 118 and the second portion 120 is larger near the flat portion 138 than near the rounded portion 136. For example, the distance between the inner surface 116 of the housing 102 and the rounded portion 136 of the sidewall 134 may be approximately 0.1 mm to approximately 0.2 mm, while the distance between the inner surface 116 of the housing 102 and the flat portion 138 of the sidewall 134 may be approximately 1 mm to approximately 3 mm. For example, the distance between the inner surface 116 of the housing 102 and the rounded portion 136 of the sidewall 134 may be approximately 0.13 mm, while the distance between the inner surface 116 of the housing 102 and the flat portion 138 of the sidewall 134 may be approximately 2 mm.

[0019] The first portion 118 of the cap 106 may include a third port 132 that provides access to the recess 140. Thus, when the cap 106 is coupled to the housing 102, the third port 132 provides access to the interior of the housing 102 via a liquid passageway that extends through the port 112 and the space disposed between the sidewall 134, preferably a flat portion 138 of the sidewall 134, and the inner surface 116 of the housing 102. Arrow A is shown in FIG. 2 within this liquid passageway to indicate the direction in which liquid introduced through the third port 132 flows into the housing 102.

[0020] The first portion 118 of the cap 106 may further include a detent 148, which may be useful for positioning the biological indicator 100 within a decontamination system. That is, the detent 148 may mate with a corresponding mating feature of the decontamination system, and the third port 132 is optimally positioned to mate with any tubing or flow connector that may be used to deliver and withdraw liquid, such as a decontaminant or neutralizing agent, into and from the housing 102. Because liquid introduced into the housing 102 must be withdrawn from the housing to enable accurate assessment of microbial growth after treatment, liquid removal may be facilitated when the biological indicator 100 is in a substantially horizontal position, i.e., substantially perpendicular to gravity, with the third port 132 facing downward. A vent 150 may also be provided in the cap 106, preferably in the first portion 118. The vent 150 allows air to be displaced from inside the housing 102 by any liquid introduced into the housing. The vent 150 also facilitates the removal of liquid from the inside of the housing 102 by allowing air to re-enter the housing 102 as liquid is withdrawn.

[0021] The insert 108 is provided for two reasons. First, the insert helps maintain the position of the carrier 110 at the bottom of the housing 102. Second, the insert is used to pierce the seal 128, allowing the growth medium 124 to flow from the liquid chamber 122 into the housing 102 and submerge the carrier 110. As best seen in FIG. 2 , the insert 108 includes a tip portion 152. The tip portion 152 can have a spike-like configuration, which may be branched, for example, including two or more tines 154. The insert 108 can be made of a suitable material, for example, a polymer such as a cycloolefin polymer, and the tines 154 can have a suitable configuration, for example, a thickness of about 0.2 mm to about 1 mm, for example, about 0.5 mm, such that the tines 154 can bend when subjected to downward pressure. Thus, when the cap 106 is pressed downward, the tip portion 152 pierces the seal 128, which can be a film such as foil, for example, aluminum foil. When seal 128 and tip portion 152 initially contact, teeth 154 bend toward each other before the seal is punctured. Once seal 128 is punctured, teeth 154 return to their original position, thereby enlarging the hole made in seal 128. Each tooth 154 may further include surface features, such as ribs 156, which may further enlarge the hole in seal 128 as seal 128 moves downward over them.

[0022] In accordance with the embodiments illustrated and described herein, Applicant has devised methods and variations thereof for using a biological indicator having the aforementioned features. First, the biological indicator can be received by a user, such as a medical professional. Next, the biological indicator can be placed in a liquid chemical decontamination system. In some variations, the biological indicator can be positioned horizontally within the chamber. In further variations, the biological indicator is positioned with the third port facing downward. Next, a liquid decontamination agent can be flowed into the housing through the third port in the cap. The liquid decontamination agent can then be removed from the housing through the third port in the cap. After the decontamination procedure is complete, the biological indicator can be removed from the chamber. The cap can then be depressed, and the seal can be pierced by driving the upper portion of the insert through the seal, allowing the growth medium in the cap's liquid chamber to flow through the puncture in the seal and into the housing, immersing the carrier. At the same time, the vent 150 and the third port 132 are blocked by the housing 102.

[0023] Any of the examples or embodiments described herein may include various other features in addition to or in place of those described above. The teachings, representations, embodiments, examples, etc. described herein should not be considered in isolation from one another. Various suitable ways in which the teachings herein can be combined should be apparent to those of ordinary skill in the art in view of the teachings herein.

[0024] While exemplary embodiments of the subject matter contained herein have been illustrated and described, further adaptations of the methods and systems described herein may be achieved by appropriate modifications without departing from the scope of the claims. Furthermore, where the methods and steps described above indicate certain events occurring in a particular order, it is intended that certain steps need not be performed in the order described, but may be performed in any order so long as the steps allow the embodiment to function for its intended purpose. Accordingly, to the extent there are variations of the invention that are within the spirit of the disclosure or equivalent to the invention as found in the claims, this patent is intended to cover those variations as well. Some such variations will be apparent to those skilled in the art. For example, the examples, embodiments, configurations, materials, dimensions, proportions, steps, etc., described above are exemplary. Therefore, the claims should not be limited to the specific details of structure and operation shown in the description and drawings.

[0025] [Embodiment] (1) A biological indicator, a housing defining a longitudinal axis and having a first port; a cap coupled to the housing, the cap comprising: a first portion disposed outside the housing; a second portion disposed at least partially inside the housing, the second portion including a second port and a fluid chamber containing a growth medium, and a seal covering the second port and defining a lower boundary of the fluid chamber; a cap; an insert disposed within the housing, the insert having a tip portion disposed along the longitudinal axis;

[0023] A biological indicator, including: (2) A biological indicator as described in embodiment 1, wherein the second port of the second portion of the cap is arranged within the housing and around the longitudinal axis of the housing. (3) A biological indicator according to any one of claims 1 to 2, wherein the second portion of the cap includes a sidewall including a rounded portion and a flat portion, and the sidewall of the second portion defines a lateral boundary of the liquid chamber. (4) The biological indicator of any one of claims 1, 2, or 3, wherein the first portion of the cap includes a third port. (5) A biological indicator according to any one of claims 3 to 4, further comprising a liquid passage extending through a space disposed between the side wall of the second portion of the cap and the inner surface of the housing.

[0026] (6) A biological indicator according to any one of claims 3 to 4, further comprising a liquid passage extending through a space disposed between the flat portion of the side wall of the second portion of the cap and the inner surface of the housing. (7) A biological indicator according to any one of embodiments 1 to 6, wherein the cap further comprises a detent. (8) A biological indicator as described in embodiment 7, wherein the detent is disposed within the first portion of the cap. (9) A biological indicator according to any one of embodiments 1 to 8, wherein the cap further comprises an air vent. (10) A biological indicator according to embodiment 9, wherein the vent hole is located within the first portion of the cap.

[0027] (11) A biological indicator according to any one of embodiments 1 to 10, wherein an ampoule is not disposed within the housing. (12) A biological indicator according to any one of embodiments 1 to 11, wherein the cap is connected to the housing via a friction fit. (13) The biological indicator of embodiment 12, wherein the friction fit includes contact between an inner surface of the first portion of the cap and an outer surface of the housing. (14) A biological indicator according to any one of embodiments 1 to 13, wherein the seal comprises a film. (15) The biological indicator of embodiment 14, wherein the film comprises a foil.

[0028] (16) A biological indicator according to any one of embodiments 1 to 15, wherein the tip portion comprises a spike. (17) The biological indicator of embodiment 16, wherein the spike comprises a branched spike. (18) The biological indicator of embodiment 17, wherein the branched spike comprises at least two teeth. (19) The biological indicator of embodiment 18, wherein each of the at least two teeth includes at least one rib. (20) A method of using a biological indicator, comprising: receiving the biological indicator, the biological indicator comprising: a housing defining a longitudinal axis and having a first port; a cap coupled to the housing, the cap comprising: a first portion disposed outside the housing; a second portion disposed at least partially inside the housing, the second portion including a second port and a fluid chamber containing a growth medium, and a seal covering the second port and defining a lower boundary of the fluid chamber; Including cap and an insert disposed within the housing, the insert having a tip portion disposed along the longitudinal axis; and placing the biological indicator in a chamber of a decontamination system; flowing a liquid decontamination agent into the housing through a third port in the cap; removing the liquid decontamination agent from the housing through the third port in the cap; A method comprising:

[0029] (21) The method of embodiment 20, wherein the step of disposing the biological indicator in the chamber includes the step of positioning the biological indicator in a substantially horizontal position. (22) The method of embodiment 20 or 21, wherein the step of placing the biological indicator in the chamber includes a step of positioning the biological indicator so that the third port faces downward. (23) removing the biological indicator from the chamber; depressing the cap against the housing; piercing the seal; 23. The method of embodiment 20, 21, or 22, further comprising: (24) The method of embodiment 23, further comprising the step of submerging a spore disc in the growth medium. (25) The method of any one of claims 23 to 24, wherein the step of piercing the seal is performed by driving the tip portion of the insert through the seal while pressing the cap down against the housing.

[0030] (26) The method of any one of claims 21 to 25, wherein the tip portion comprises a spike. (27) The method of embodiment 26, wherein the spike comprises a branched spike. (28) The method of embodiment 27, wherein the branched spike includes at least two teeth.

Claims

1. A biological indicator comprising: Housing and a cap coupled to the housing, the cap comprising: a first portion disposed outside the housing; a second portion disposed at least partially within the housing, the second portion including a sidewall; a port disposed through the first portion; a cap; Including, the port provides access to a recess disposed between the first portion and the second portion, the recess including an irregular shape defined at least in part by the sidewall and enlarged adjacent the port; a liquid passageway extending through a space disposed between the sidewall of the second portion of the cap and an inner surface of the housing; the cap further includes a vent configured to facilitate removal of liquid from the interior of the housing by allowing air to be displaced from inside the housing by any liquid introduced into the housing through the vent and allowing air to re-enter the housing when any liquid is withdrawn through the vent; The second portion includes a fluid chamber containing a growth medium and a seal defining a lower boundary of the fluid chamber.

2. 2. The biological indicator of claim 1, wherein the second portion includes a sidewall having a rounded portion and a flat portion, and the port and the recess are both located closer to the flat portion than to the rounded portion.

3. The biological indicator of claim 2 , wherein the liquid passage extends alongside the flat portion of the sidewall.

4. The biological indicator of claim 3 , wherein the cap further comprises a detent.

5. The biological indicator of claim 4 , wherein the detent is disposed within the first portion of the cap.

6. The biological indicator of claim 1 , wherein the vent is disposed within the first portion of the cap.

7. The biological indicator of claim 6 , wherein the cap is coupled to the housing via a friction fit.

8. The biological indicator of claim 7 , wherein the friction fit comprises contact between an inner surface of the first portion of the cap and an outer surface of the housing.

9. The biological indicator of claim 1 , wherein the seal comprises a film.

10. The biological indicator of claim 9 , wherein the film comprises a foil.

11. The biological indicator of claim 6 , further comprising an insert disposed within the housing, the insert having a tip portion, the tip portion including a spike.

12. The biological indicator of claim 11 , wherein the spike comprises a bifurcated spike.

13. The biological indicator of claim 12 , wherein the bifurcated spike includes at least two tines.

14. The biological indicator of claim 13 , wherein each of the at least two teeth includes at least one rib.

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