(235 days)
As a Sterilizer Monitoring Device, the 3M™ Attest™ eBowie-Dick Test Card 10135 and 3M[™ Attest™ eBowie-Dick Card Holder 10135CH is used in conjunction with the 3MTM Attest™ eBowie-Dick Auto-reader 1190 to monitor the equipment performance of steam sterilizers each. day, as well as after a steam sterilizer repair. The 3MTM Attest™ eBowie-Dick Test Card 10135 will detect steam penetration as a means of measuring air removal efficiency. The 3M™ Attest™ eBowie-Dick Test Card 10135 and 3MTM Attest™ eBowie-Dick Card Holder 10135CH is designed for testing air removal efficiency of 132°C (270°F). 134°C (273°F), and 135°C (275°F) for 3.5 minute test cycles in dynamic-air-removal steam sterilizers with chamber volumes greater than 54L (approximately 2 cubic feet).
The 3MTM Attest eBowie-Dick Auto-reader is designed to automatically interpret, store, and display the result of the 3MTM Attest™ eBowie-Dick Test Card.
The 3M™ Attest™ eBowie-Dick Test Card consists of a laminated construction with a lead-free steam-sensitive chemical indicator positioned at the end of a lumen challenge. The 3MTM Attest™ eBowie-Dick Test Card undergoes a change in electrical resistance upon exposure to saturated steam. The test card includes a lumen challenge which is designed to restrict air removal and steam perfusion. At the completion of a Bowie-Dick test cycle, the resistance of the 3MTM Attest™ eBowie-Dick Test Card is read out using the 3MTM Attest™ eBowie-Dick Autoreader. The 3M™ Attest™ eBowie-Dick Test Card will reach a PASS value when adequate air removal and steam profusion is achieved. An air removal failure and or a steam penetration failure is indicated by a FAIL result.
The 3MTM Attest™ eBowie-Dick Card Holder is a reusable sterilizable plastic container for the Test Card which serves to support the laminated construction of the Test Card during the vacuum and pressure cycles of the air removal test, as well as anchor the Test Card in place inside the sterilization chamber through the increased mass of the Card Holder plus Test Card combination.
The 3M™ Attest™ eBowie-Dick Auto-reader is a wall powered electrical resistance measurement device which receives a processed Test Card via the card slot and contains pairs of internal mechanical contacts to probe the metallic contact pads on the Test Card. The Autoreader detects and confirms proper insertion of the Test Card, measures the PANI sensor electrical resistance, and returns a visible PASS, FAIL, or ERROR state indication to the user. The Auto-reader utilizes embedded firmware to detect and read the resistance of a Test Card. The device also includes USB or BLE connectivity for integrating with the optional 3M™ AttestTM Connect Software platform.
This document describes the 3M™ Attest™ eBowie-Dick Test, a system designed to monitor steam sterilizer performance for air removal efficiency.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are derived from the Special Controls outlined in the document, reflecting the requirements for non-clinical performance testing. The reported device performance is based on the summary of bench studies provided.
| Acceptance Criteria (Derived from Special Controls) | Reported Device Performance |
|---|---|
| Non-clinical Performance Testing: | Supported by Bench Studies: |
| (i) Performance comparison with a scientifically justified comparator. | - Comparison of air pocket size and position in a reference test pack to the sensor in eBD Test card for inadequate cycles, demonstrating comparable pass/fail testing. |
| (ii) Demonstrate measured response is dependent on sterilization cycle parameter(s). | - Not explicitly detailed, but implied by the device's function of detecting steam penetration (a cycle parameter) and linking resistance change to saturated steam exposure. |
| (iii) Identify relevant validation parameters, samples, conditions, and data analysis. | - Studies included characterization of air removal from eBD Test card lumen, testing of the sensor in adequate and inadequate cycles, quantifying resistance-color relationship, and determining accuracy, precision, and dynamic range of the auto-reader. Specific validation parameters and acceptance criteria for each parameter are not explicitly listed in the summary, but the breadth of testing indicates these were established. |
| (iv) Evaluate sensitivity and specificity to determine passing/failing conditions. | - Sensitivity and specificity testing as a function of changes in vacuum level and pressure during the conditioning phase of dynamic air removal cycles to support low occurrences of false positive/negative results. |
| (v) Determine and validate accuracy, precision, and range of the measuring device. | - Determination of accuracy, precision, and dynamic range of the 3M™ Attest™ eBowie-Dick Auto-reader 1190 for measuring resistance. |
| (vi) Evaluate end point stability. | - Testing showing endpoint stability for Adequate and Inadequate Cycles as a function of Dwell Time in the sterilizer and cooling time before reading. |
| (vii) Demonstrate reader maintains a defined range of accuracy over a defined time interval. | - Independent verification of Auto-reader accuracy completed during manufacturing final functional testing using external reference cards with verified resistance values. (This implies ongoing accuracy maintenance, but doesn't explicitly state a "defined time interval" for field accuracy.) |
| Shelf Life Performance Data. | - A shelf-life study and a hot and cold excursion stability study provided to demonstrate product performance is maintained throughout the 6-month shelf life. |
| Software Verification, Validation, and Hazard Analysis. | - Adequate software development, test plans, and documentation demonstrated according to FDA guidance. |
| Electromagnetic Compatibility (EMC) and Electrical Safety Performance Data. | - EMC Immunity testing conducted using consensus standard 60601-1-2. Electrical Safety testing conducted per IEC 61010-1. |
| Human Factors and Usability Engineering. | - Evaluated via simulated-use testing with representative users in accordance with FDA guidance, with no observed use errors, close calls, or difficulties for critical tasks. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the specific sample sizes for each performance test (test sets for sensitivity, specificity, accuracy, precision, endpoint stability, etc.). It describes the types of tests conducted but not the number of units or cycles tested within each.
The data provenance is retrospective (bench studies already conducted) and likely originated from 3M's internal laboratories based in the USA (St. Paul, MN). The data is entirely non-clinical.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of human experts to establish ground truth for the test set in the context of interpreting the eBowie-Dick test results. The device is designed for automatic interpretation. The ground truth for the performance testing appears to be based on physical measurements and established scientific principles of sterilization (e.g., inadequate vs. adequate cycles, presence of non-condensable gasses, comparison to ISO 11140:2007-5 Standard Test Pack).
4. Adjudication Method for the Test Set
Not applicable. The device's automated interpretation (Pass/Fail/Error via auto-reader) means there is no human adjudication process described or required for its primary function. Ground truth determination for performance studies would be based on instrument readings and physical conditions.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This device is an automated physical/chemical indicator system. It does not involve human readers interpreting images or data where a comparative effectiveness study with and without AI assistance would be relevant. The benefit is explicitly stated as increased testing sensitivity with a digital measurement and reduced false results/repeat testing with an automatic reader, suggesting it is intended to replace or significantly simplify manual interpretation or older methods.
6. Standalone (Algorithm Only Without Human-in-the-Loop) Performance Study
Yes. The entire performance testing described, particularly for sensitivity, specificity, accuracy, precision, and endpoint stability, assesses the performance of the eBowie-Dick Test Card and Auto-reader system in a standalone capacity. The Auto-reader automatically interprets the card's resistance to provide a Pass, Fail, or Error result. Human interpretation is not part of the core performance evaluation of the device itself.
7. Type of Ground Truth Used
The ground truth used for performance testing (e.g., sensitivity, specificity) is based on:
- Physical Conditions: Deliberately created "inadequate" (e.g., specific air pocket sizes, insufficient vacuum/pressure) and "adequate" sterilization cycles.
- Comparison to Reference Standards: Performance compared to the "Standard Test Pack as defined in ISO 11140:2007-5."
- Known States: Testing the sensor in known adequate and inadequate cycles to show expected pass/fail results.
- Instrument Calibration/Verification: Verified resistance values for Auto-reader accuracy.
8. Sample Size for the Training Set
The document does not provide a specific sample size for a "training set." The device utilizes embedded firmware with "predefined thresholds" for interpreting resistance measurements. This suggests the thresholds were established through internal development and testing, but the explicit size of any dataset used to develop or "train" these thresholds is not disclosed.
9. How the Ground Truth for the Training Set Was Established
Given the nature of the device (measuring electrical resistance that changes with saturated steam exposure), the "ground truth" for establishing the predefined thresholds would likely involve:
- Controlled Laboratory Experiments: Exposing test cards to precisely controlled steam sterilization cycles (adequate and various levels of inadequate) in laboratory settings.
- Physical Measurements: Correlating the electrical resistance measurements from these controlled exposures with the known physical conditions (e.g., presence/absence of saturated steam, degree of air removal failure).
- Engineering Principles: Establishing the resistance values that correspond to a successful steam penetration (Pass) and those that indicate a failure (Fail). This would be based on the scientific principles of the chemical indicator's electrical resistance change upon exposure to saturated steam.
- Comparison to Existing Standards: Aligning the "Pass" and "Fail" thresholds to be equivalent to the performance of established Bowie-Dick tests, such as those compliant with ISO 11140:2007-5.
§ 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).