EZTest® - Gas self contained biological indicators are for monitoring the efficacy of ethylene oxide gas sterilization processors. Performance characteristics are established in accordance with USP XXIII for the 600mg/l process.

Device Description

The biological indicator consists of a self-contained unit which includes: bacterial spores inoculated onto a paper carrier, a small glass ampule containing sterile culture medium and color indicator, and a plastic vial that serves as the culture tube. This unit complies to the performance characteristics described in the USP XXIII.

AI/ML Overview

The acceptance criteria and the study proving the device meets them are described below:

1. Table of Acceptance Criteria and Reported Device Performance

The EZTest® - Gas biological indicator is designed to meet the performance characteristics described in the USP XXIII. The document outlines several characteristics that were evaluated.

Acceptance Criteria (Based on USP XXIII guidelines)	Reported Device Performance
Bacterial Spore Species: Bacillus subtilis, ATCC 9372 or equivalent	Bacillus subtilis, ATCC 9372 or equivalent (no specific performance metric, but states that this is the organism used and USP XXIII requires its use for EO sterilization monitoring).
Bacterial Spore Concentration: Between 0.5 x 10⁶ and 5 x 10⁶ CFU for a 10⁶ labeled concentration.	Population of spores on paper carrier will be between 0.5 x 10⁶ and 5 x 10⁶, labeled as a 10⁶ concentration. SGM Biotech, Inc. specification matches this guideline. (Performance is stated as meeting the spec, not a measured value from this specific study, but inherent to product design).
Sample Purity: (Implied clean culture of target spore species)	No specific performance metric given, but "Sample purity" was an evaluated characteristic.
Resistance Characteristics:
- D-values at 600 mg/l EO, 54°C, 60% RH.	"D values at 600 mg/l EO, 54°C, 60% RH" were evaluated. No specific numerical D-value is reported in this summary, but the device is concluded to "meet the USP XXIII requirements" for this parameter.
- Survival/Kill times at 600 mg/l EO, 54°C, 60% RH.	"Survival/Kill times at 600 mg/l EO, 54°C, 60% RH" were evaluated. No specific numerical times are reported in this summary, but the device is concluded to "meet the USP XXIII requirements" for this parameter.
Incubation Readout Time Validation: 48 hours incubation based on CDRH guideline.	"Validation of 48 hours incubation read out time following the CDRH guideline" was performed.
Effect of Holding Time:	"Resistance characteristics were evaluated to determine the effect of holding time after the exposure to the sterilant until incubation, upon the recovery of injured spores." (No specific result provided, but the evaluation was performed).
Effect of pH Indicator:	"Evaluation of the effect of the pH indicator upon the recovery of injured spores" was performed. (No specific result provided, but the evaluation was performed).
Effect of Sterilization Process on Media Growth Support:	"Validation of the effect of the sterilization process on the ability of the media to support the growth of injured spores" was performed. (No specific result provided, but the evaluation was performed).
Product Stability: Stability over 18-month shelf life claim.	"Stability of the product over the eighteen (18) month shelf life claim" was evaluated. (No specific result provided, but the evaluation was performed).

The ultimate reported performance is that the EZTest® - Gas "meets the USP XXIII requirements" for the tested parameters.

2. Sample Size Used for the Test Set and Data Provenance

Sample Size: The document states that claims were evaluated using "at least three (3) spore lots using different spore crops and different media lots." This indicates that multiple units from these lots would have been tested for each characteristic. However, the exact number of individual biological indicators tested is not specified.
Data Provenance: The document does not explicitly state the country of origin for the data or whether the study was retrospective or prospective. Given that it's a 510(k) submission to the FDA, the studies would likely have been conducted prospectively under controlled laboratory conditions, possibly in the USA, to generate the required performance data.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications

This type of device (biological indicator) does not typically involve human experts establishing a "ground truth" in the way an imaging AI algorithm would. The "ground truth" for a biological indicator is determined by the growth or non-growth of bacterial spores after exposure to a sterilization process and subsequent incubation. This is an objective biological outcome, not a subjective interpretation by human experts.

4. Adjudication Method for the Test Set

Not applicable. As explained above, the "ground truth" is an objective biological outcome (spore growth/no growth), not a subjective assessment requiring adjudication by multiple experts.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for diagnostic devices that involve human interpretation (e.g., radiology AI), not for biological indicators that assess the efficacy of sterilization directly through objective biological endpoints.

6. Standalone Performance Study

Yes, a standalone study (algorithm only without human-in-the-loop performance) was done. For a biological indicator, "standalone performance" refers to the device's ability to accurately reflect the presence or absence of viable spores after a sterilization cycle. The listed evaluations (D-values, survival/kill times, incubation readout, etc.) directly assess the device's inherent performance characteristics in a controlled laboratory setting, independent of human interpretation to determine the primary outcome. The reading of the color change is a direct function of the device's biological and chemical components, not a human reader's diagnostic skill.

7. Type of Ground Truth Used

The ground truth used is based on biological outcomes (growth or non-growth of Bacillus subtilis spores) and established industry standards as defined by the USP XXIII (United States Pharmacopoeia). This involves direct observation of microbial growth (manifested by a color change in the medium) after defined exposure to ethylene oxide and subsequent incubation.

8. Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of machine learning or AI. For a biological indicator, the development and manufacturing process doesn't typically involve machine learning training data. Instead, the "training" (or rather, development and validation) of such a device relies on extensive laboratory testing and adherence to established microbiological and sterilization science principles.

The description implies that the manufacturing process involves "a manufacturing in-process quality control system to specifications defining exacting parameters for production to assure a consistent product and good manufacturing procedures." This ongoing quality control and specification adherence serve a similar purpose to ensuring a consistent "learned" behavior in an AI model, but through traditional engineering and scientific validation.

9. How the Ground Truth for the Training Set Was Established

Not applicable in the AI/ML sense. For this device, the "ground truth" for establishing its design and specifications (analogous to a training set for AI) would have been established through:

Established microbiological principles: Understanding the resistance of Bacillus subtilis spores to ethylene oxide.
USP XXIII guidelines: Adherence to defined performance characteristics for biological indicators.
Historical data and scientific literature: Leveraging decades of knowledge related to sterilization processes and biological indicator design.
Internal R&D and testing: SGM Biotech's own experimentation to develop their specific media formulation, spore carrier, and device configuration to meet the USP XXIII standards.

The "ground truth" for manufacturing quality assurance is established by testing each lot against the USP XXIII specifications for spore count, resistance, and purity.

Summary

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K930683

Mar - 4 1997

ﺘ

"510(k) SUMMARY"

[as required by Section 807.92(c)]

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10 Evergreen Dr. Suite

John R. Gillis, Ph.D.
President

"510(k) Summary"

[as required by Section 807.92(c)]

510(k) Notification

EZTest® - Gas biological indicator monitor for ethylene oxide gas sterilizers

Submitted by:

SGM Biotech, Inc. 10 Evergreen Drive, Suite E Bozeman, MT 59715

Gontact:

John R. Gillis, Ph.D. President Phone: (406) 585-9535 FAX: (406) 585-9219

This summary was prepared on October 22, 1996 [as required by Section 807.92(a)(1)]

DEVICE:

Trade name: EZTest® - Gas biological indicator Common name: Self-contained biological indicator for ethylene oxide gas [as required by Section 807.92(a)(2)]

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SUBSTANTIALLY EQUIVALENT TO THE FOLLOWING LEGALLY MARKETED DEVICES:

ATITEST® - PyMaH Corp. (K895704) ATTEST® - 3M Co. (pre 1976 device) PROOF® - AMSCO (K801109) [as required by Section 807.92(a)(3)]

DESCRIPTION OF DEVICE: EZTest® - Gas

[as required by Section 807.92(a)(4)]

Spores

Bacterial endospores of Bacillus subtilis, ATCC 9372 or equivalent, are inoculated onto a 591 Schleicher & Schuell, Inc. filter paper carrier* cut into strips of a convenient size to be placed inside the plastic body of the device. The population of spores on each individual piece of paper will be between 0.5 x 10 (0) and 5 x 10 (0).

The spore concentration will be labeled as a 10° concentration. The guideline in the general section on sterilization, USP XXI, p. 121, indicates that the population of spores for a 10° biological indicator should be between 0.5 x 108 and 5.0 x 10°. This is also the SGM Biotech, Inc. specification.

The population data is based on the heat shock population assay. The heat shock procedure is 65°C to 70°C for 15 minutes as outlined in USP XXIII official monographs, P. 204.

reference USP XXIII p. 202

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Culture Tube

The culture tube is made of a polypropylene. The plastic culture tube is a) 1.75" in length and 0.34" in OD. The 0.02" wall allows the culture tube to be flexible so that the culture media glass ampule can be broken to activate the test.

Culture Medium

The culture medium, consisting of a formulated soybean casein digest base, is filled into ampules of Type I pharmaceutical grade glass, flame sealed and sterilized. The sealed ampules are of convenient size to be placed into the plastic body with the spore paper. Following filling, the ampules are exposed to a steam processing cycle to render them sterile. The ampule is a thin wall glass which allows it to be easily crushed when the plastic body is compressed. This provides the spores with nutrient medium for growth.

The culture medium has a pH indicator (bromothymol blue or phenol red) added to it which appears as a blue green or orange red color respectively prior to crushing for incubation. When the spores grow, they produce acid and alter the pH. This causes the medium to change to a vellow color. If the medium changes to yellow, viable spores are present. If the medium remains the original blue green or orange red color, the spores did not grow, which means they are not viable. Therefore, if the ethylene oxide gas sterilization process was effective, the medium will stay clear and maintain the original color. If the process was not effective, the spores will turn the medium yellow and/or cloudy.

Filter Paper Vent

The plastic body is closed with a ½" disc filter vent material that allows the exchange of gases from the sterilizer or from the environment.

Cap

A polypropylene plastic cap is used to hold the vent material in place. This cap has a small hole in it to allow gas to freely move in and out of the body.

These materials are all compatible with ethylene oxide gas sterilization. These materials have no effect on the resistance of the biological indicator. They are similar to those used in the 3M Attest®.

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INTENDED USE OF DEVICE:

[as required by Section807.92(a)(5)]

The operational principles of the device are as follows. The EZTest® -Gas indicator is placed into a sterilizer load and an appropriate sterilization cycle is run. As sterilization conditions are met, the bacterial spores are destroyed by logarithmic chemical death principles. Following the sterilization cycle, the Bl is removed from the load, the operator activates the self-contained ampule by mechanically flexing the side wall of the plastic vial or by using the plastic crusher provided to break the glass ampule containing the culture medium. The activated EZTest® -Gas Bl is then placed in an incubator which will provide temperatures 35°C to 39°C which is conducive for growth of any bacterial spores which might have survived the sterilization cycle. Microbial growth of the indicator organisms will produce acid in the microbiological culture medium containing the pH indicator, thus lowering the pH of the solution and invoking a yellow and/or cloudy color change of the media components. If all spores have been killed the media will remain clear and maintain its original color.

SUMMARY OF THE TECHNOLOGICAL CHARACTERISTICS OF EZTest® - Gas COMPARED TO THE CHARACTERISTICES OF THE PREDICTATE DEVICE:

[as required by Section 807.92(a)(6)]

EZTest® - Gas, being similar in type to other products presently in the marketplace whose useful intent is the monitoring of sterilizer efficacy, has been determined to be safe and effective.

Active components of the indicator have been in routine use more than 20 years. They predate the medical device amendment of the Food and Drug Cosmetic Act and are recognized by the United States Pharmacopoeia XXIII.

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Spores of Bacillus subtilis var niger are the microorganisms of choice for the evaluation of ethylene oxide gas sterilization processes because of their high degree of resistance to this type of processes. The USP XXIII specifically indicates that this species of microorganism be used to monitor ethylene oxide gas sterilization process. Numerous biological indicators on the marketplace, such as Proof®, Attest®, and ATTTest®, use these microorganisms and have proved to be both safe and efficacious.

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EZTest® - Gas biological indicators are produced under a manufacturing in-process quality control system to specifications defining exacting parameters for production to assure a consistent product and good manufacturing procedures. Upon completion of production, each lot is inspected and tested to a quality assurance specification to affirm functional conformance to product specifications. A significant portion of the quality assurance specification is testing to the performance characteristics of biological indicators as outlined in USP XXIII. Such compliance is required on each lot prior to release.

DETERMINATION OF SUBSTANTIALLY EQUIVALENT BASED ON PHYSICAL CHARACTERISTICS:

[as required by Section 807.92(b)(1)]

.... ... ... ...

A comparison is provided of the legally marketed predicate devices describing similarities and differences such as technology and other important characteristics.

A. ATITest® PyMaH/ATI (K902344):

This device is exactly the same as the PyMaH ATITest® disclosed in 510(k) notification K902344. The ATITest® was developed by SGM Biotech for private label to PyMaH/ATI.

B. Attest® 3M - Pre '76 Product:
This device is virtually identical in size and shape to the 3M Attest®. It has virtually the same carrier material for the spores with the same concentration of Bacillus subtilis spores (10°). The volume of culture medium in the crushable glass ampule is similar. The pH indicator is bromothymol blue in the Attest®, as well as the EZTest®. Therefore, when viable spores grow, the color changes from blue green to yellow.

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The glass of the crushable glass ampule in Attest® is virtually the same as that used in the EZTest®.

The culture medium in the 3M Attest® is a soybean casein digest derived culture medium. EZTest® uses a soybean casein digest derived culture medium. The specific formulation of the SGM Biotech medium is considered proprietary and confidential.

Activation of the 3M Attest® biological indicator devices are performed by compressing the flexible sides of the plastic culture tubes to break the crushable glass ampule containing the culture medium. This is exactly the way EZTest® -Gas is activated.

C. PROOF® - AMSCO (K801109):

The EZTest® - Gas is similar to the AMSCO PROOF® in that:

1. similar concentration B. subtilis spores are used, i.e. 10°.
1. spores are carried on chromatography grade pure cotton derived filter paper.
1. culture medium is contained in crushable glass ampule.
1. culture medium is a soybean casein digest derived medium.
1. spore growth is detected by lowering the pH of the culture medium. This shift in pH is detected by the addition of phenol red to the medium which is similar to the EZTest - Gas.

DETERMINATION OF SUBSTANTIALLY EQUIVALENCE BASED ON IN USE PERFORMANCE:

[as required by Section 807.92(b)(2)]

The performance of EZTest® - Gas was evaluated for the following characteristics (Certificate of Performance - attached):

a. Bacterial spore species
b. Bacterial spore concentration
c. Sample purity
d. Resistance characteristics including:
- 1. D values at 600 mg/l EO, 54°C, 60% RH.
- 1. Survival/Kill times at 600 mg/l EO. 54°C, 60% RH.

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e. Claims were evaluated using at least three (3) spore lots using different spore crops and different media lots.
Resistance characteristics were evaluated to determine the f. effect of holding time after the exposure to the sterilant until incubation, upon the recovery of injured spores.
g. Validation of 48 hours incubation read out time following the CDRH quideline.
h. Evaluation of the effect of the pH indicator upon the recovery of injured spores.
i. Validation of the effect of the sterilization process on the ability of the media to support the growth of injured spores.
Stability of the product over the eighteen (18) month shelf life j. claim.

CONCLUSION:

[as required by Section 807.92(b)(3)]

EZTest® - Gas is appropriate for monitoring ethylene oxide gas sterilization processes of 600 mg/l EO, 54°C, 60% RH and EZTest® - Gas meets the USP XXIII requirements.

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Regulation Number and Section

§ 880.2800 Sterilization process indicator.

(a)
Biological sterilization process indicator —(1)Identification. A biological sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor adequacy of sterilization. The device consists of a known number of microorganisms, of known resistance to the mode of sterilization, in or on a carrier and enclosed in a protective package. Subsequent growth or failure of the microorganisms to grow under suitable conditions indicates the adequacy of sterilization.(2)
Classification. Class II (performance standards).(b)
Physical/chemical sterilization process indicator —(1)Identification. A physical/chemical sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor one or more parameters of the sterilization process. The adequacy of the sterilization conditions as measured by these parameters is indicated by a visible change in the device.(2)
Classification. Class II (performance standards).