US-20260124332-A1 - TEST DEVICE, STERILIZATION MONITORING SYSTEM AND METHOD

US20260124332A1US 20260124332 A1US20260124332 A1US 20260124332A1US-20260124332-A1

Abstract

A test device for monitoring sterilization using a steam sterilant in a chamber is provided. The test device includes a test stack. The test stack includes an entrance layer including an entrance hole. The test stack further includes a sensor layer spaced apart from the entrance layer. The sensor layer includes a pair of electrodes disposed on the sensor layer. The test stack further includes a sensor coating disposed on a portion of the sensor layer and including an electrically active polymer. The test stack further includes a channel layer disposed between the entrance layer and the sensor layer. The channel layer includes an internal channel. The internal channel is configured to allow a flow of steam sterilant from the entrance hole to the sensor coating.

Inventors

G. Marco Bommarito
Wensheng Xia
Benjamin M. Wilke
Naiyong Jing

Assignees

SOLVENTUM INTELLECTUAL PROPERTIES COMPANY

Dates

Publication Date: 20260507
Application Date: 20230913

Claims (20)

1 . A test device for monitoring sterilization using a steam sterilant in a chamber, the test device comprising: a test stack defining a major plane and a perimeter, the test stack comprising: an entrance layer comprising an entrance hole extending through the entrance layer, wherein the entrance hole is in fluidic connection with the chamber; a sensor layer spaced apart from the entrance layer, wherein the sensor layer comprises a pair of electrodes disposed on the sensor layer; a sensor coating disposed on a portion of the sensor layer and comprising an electrically active polymer, wherein the sensor coating is spaced apart from the entrance hole at least along the major plane of the test stack, wherein the sensor coating is electrically coupled to the pair of electrodes; and a channel layer disposed between the entrance layer and the sensor layer, wherein the channel layer comprises an internal channel defining a channel length along the major plane and a channel depth normal to the major plane, wherein the internal channel is spaced apart from the perimeter of the test stack, wherein the internal channel extends through the channel layer along the channel depth, wherein the internal channel extends from the entrance hole to the sensor coating at least along the channel length, such that the internal channel fluidically connects the entrance hole with the sensor coating; wherein the internal channel is configured to allow a flow of the steam sterilant from the entrance hole to the sensor coating, and wherein the sensor coating is configured to change an electrical impedance across the pair of electrodes upon contact of the steam sterilant with the sensor coating.
2 . The test device of claim 1 , wherein the internal channel is at least partially non-linear along the channel length.
3 . The test device of claim 2 , wherein the internal channel comprises a first end portion disposed in fluidic connection with the entrance hole, a second end portion spaced apart from the first end portion and disposed in fluidic connection with the sensor coating, and a main portion extending from the first end portion to the second end portion along the channel length, wherein the first end portion is at least partially aligned with the entrance hole, wherein the second end portion is at least partially aligned with the sensor coating, and wherein the main portion is at least partially non-linear along the channel length.
4 . The test device of claim 3 , wherein the first end portion is circular.
5 . The test device of claim 4 , wherein the entrance hole is circular, and wherein a diameter of the first end portion is greater than a diameter of the entrance hole by a factor of at least 2.
6 . The test device of claim 3 , wherein the second end portion is substantially rectangular.
7 . The test device of claim 3 , wherein the main portion comprises a first linear section extending from the first end portion, a curved section extending from the first linear section, and a second linear section extending from the curved section to the second end portion.
8 . The test device of claim 7 , wherein a length of the first linear section is greater than a length of the second linear section by a factor of at least 2.
9 . The test device of claim 3 , wherein the main portion has a serpentine shape having a plurality of bends.
10 . The test device of claim 3 , wherein a width of the main portion is less than a width of each of the first end portion and the second end portion.
11 . The test device of claim 3 , wherein at least a portion of each of the pair of electrodes is disposed between the sensor coating and the sensor layer, such that a gap is defined between the pair of electrodes, wherein the gap is covered by the sensor coating, and wherein the second end portion at least surrounds the portion of each of the pair of electrodes and the gap between the pair of electrodes.
12 . The test device of claim 1 , wherein the entrance layer and the channel layer at least partially define a cutout disposed at the perimeter of the test stack, wherein each of the pair of electrodes at least partially extends into the cutout, and wherein the cutout is configured to at least partially receive one or more terminals of a reader therein for measuring the electrical impedance across the pair of electrodes.
13 . The test device of claim 12 , wherein each of the pair of electrodes comprises a first rectangular portion electrically coupled to the sensor coating, a second rectangular portion disposed within the cutout, and a narrow elongate portion connecting the first rectangular portion to the second rectangular portion.
14 . (canceled)
15 . The test device of claim 1 , wherein the test stack further comprises: a first adhesive layer disposed between the entrance layer and the channel layer, the first adhesive layer bonding the channel layer to the entrance layer; and a second adhesive layer disposed between the channel layer and the sensor layer, the second adhesive layer bonding the channel layer to the sensor layer; wherein the internal channel further extends through each of the first adhesive layer and the second adhesive layer along the channel depth.
16 .- 22 . (canceled)
23 . The test device of claim 1 , wherein the test stack further comprises a support layer disposed adjacent to the sensor layer opposite to the channel layer, wherein the support layer at least partially forms an external surface of the test stack.
24 .- 34 . (canceled)
35 . A sterilization monitoring system comprising; the test device of claim 1 ; and a holder configured to at least partially and removably receive the test device therein.
36 . The sterilization monitoring system of claim 35 , wherein the holder comprises: a first open end configured to at least partially receive the test device therethrough; a second open end opposite to the first open end; a first portion extending from the first open end to the second open end; a second portion opposite to the first portion and extending from the first open end to the second open end; a pair of lateral portions disposed opposite to each other and connecting the first portion to the second portion, wherein the first portion, the second portion, and the pair of lateral portions together define a volume therebetween, wherein the volume extends from the first open end to the second open end and is configured to at least partially and removably receive the test device therein; a plurality of first ribs spaced apart from each other and extending from the first portion towards the second portion, wherein each of the plurality of first ribs at least partially extend between the first open end and the second open end; and a plurality of second ribs spaced apart from each other and extending from the second portion towards the first portion, wherein each of the plurality of second ribs at least partially extend between the first open end and the second open end; wherein the plurality of first ribs and the plurality of second ribs are configured to at least partially engage the test device and removably secure the test device therebetween.

Description

TECHNICAL FIELD The present disclosure relates generally to sterilization, and more particularly, relates to a test device for monitoring sterilization, a sterilization monitoring device including the test device, and a method for monitoring sterilization in a chamber. BACKGROUND Sterilization of medical and hospital equipment may not be effective until a steam sterilant has been in contact with all surfaces of materials being sterilized in a proper combination of time, temperature, and steam quality. In steam sterilizers, such as pre-vacuum steam sterilizers and gravity displacement steam sterilizers, the process of sterilization is conducted in three main phases. In the first phase, air is removed, including air trapped within any porous materials being processed. The first phase is therefore an air removal phase. The second phase is a sterilizing stage, in which a load (i.e., the articles being sterilized) is subjected to steam under pressure for a recognized, predetermined combination of time and temperature to effect sterilization. The third phase is a drying phase in which condensation formed during the first two phases is removed by evacuating the chamber. Any air that is not removed from the sterilizer during the air removal phase of the cycle or which leaks into the sterilizer during a sub atmospheric pressure stage due to, for example, faulty gaskets, valves or seals, may form air pockets within any porous materials present. Such air pockets may create a barrier to steam penetration, thereby preventing adequate sterilizing conditions being achieved for all surfaces of the load during the sterilizing phase. For example, these air pockets may prevent the steam from reaching interior layers of materials, such as hospital linens or fabrics. In some other examples, these air pockets may prevent the steam from penetrating hollow spaces of tubes, catheters, syringe needles, and the like. Further, non-condensable gas (generally air) present within the sterilizer is a poor sterilant and may decrease sterilization efficacy. A percentage of non-condensable gas in the steam should be less than or equal to 3.5% by volume. Therefore, the presence of air pockets and/or non-condensable gas may affect a steam quality of the steam sterilant. As a result, proper sterilization may not occur due to reduced steam quality. A few more factors that may affect steam quality include insufficient steam supply, water quality, degassing, design of the sterilizer chamber, etc. SUMMARY In a first aspect, the present disclosure provides a test device for monitoring sterilization using a steam sterilant in a chamber. The test device includes a test stack defining a major plane and a perimeter. The test stack includes an entrance layer including an entrance hole extending through the entrance layer. The entrance hole is in fluidic connection with the chamber. The test stack further includes a sensor layer spaced apart from the entrance layer. The sensor layer includes a pair of electrodes disposed on the sensor layer. The test stack further includes a sensor coating disposed on a portion of the sensor layer and including an electrically active polymer. The sensor coating is spaced apart from the entrance hole at least along the major plane of the test stack. The sensor coating is electrically coupled to the pair of electrodes. The test stack further includes a channel layer disposed between the entrance layer and the sensor layer. The channel layer includes an internal channel defining a channel length along the major plane and a channel depth normal to the major plane. The internal channel is spaced apart from the perimeter of the test stack. The internal channel extends through the channel layer along the channel depth. The internal channel extends from the entrance hole to the sensor coating at least along the channel length, such that the internal channel fluidically connects the entrance hole with the sensor coating. The internal channel is configured to allow a flow of the steam sterilant from the entrance hole to the sensor coating. The sensor coating is configured to change an electrical impedance across the pair of electrodes upon contact of the steam sterilant with the sensor coating. In a second aspect, the present disclosure provides a sterilization monitoring system including the test device of the first aspect. The sterilization monitoring system further includes a holder configured to at least partially and removably receive the test device therein. In a third aspect, the present disclosure provides a sterilization system including the sterilization monitoring system of the second aspect. The sterilization system further includes a sterilizer including a chamber configured to receive the holder and the test device therein. The sterilizer is configured to perform a sterilization process on the test device using a steam sterilant within the chamber. In a fourth aspect, the present disclosure provides a method for monit