(301 days)
The NAMSA Chemical Process Indicator Strip for Steam, REF TST4-S is intended for use with individual materials (i.e. pouches, pack, tray) to demonstrate that the material has been exposed to a steam sterilization process to distinguish between processed and unprocessed goods. The NAMSA Chemical Process Indicator Strip for Steam will transition from an initial yellow color to a dark brown/black signal color when exposed to high temperature steam at the following time and temperature intervals as a process indicator:
- 121°C for 30 minutes (gravity cycle) .
- 134℃ for 3 minutes (pre-vacuum) .
The NAMSA Chemical Process Indicator Strip for Steam utilizes NAMSA indicating ink SSI-10-YBI that when exposed to high temperature steam turns from an initial yellow color to a permanent dark brown/black signal color. The intended use for the NAMSA Chemical Process Indicator Strip for Steam processes is a Process Indicator intended for use by health care facilities to distinguish between processed and unprocessed goods. The NAMSA Chemical Process Indicator Strip for Steam will transition from an initial yellow color to a permanent dark brown/black signal color when exposed to high temperature steam at the following time and temperature intervals:
- 121℃ for 30 minutes (gravity cycle) ●
- 134℃ for 3 minutes (pre-vacuum) .
This document describes the NAMSA Chemical Process Indicator Strip for Steam and its performance testing to demonstrate substantial equivalence to a predicate device.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are derived from ANSI/AAMI/ISO 11140-1:2005 guidelines for Class 1 Process Indicators for STEAM. The reported device performance indicates that the NAMSA Chemical Process Indicator Strip for Steam met these criteria.
| Test Condition | Test Time | Test Temperature | Acceptance Criteria: No change or a change markedly different from specified | Acceptance Criteria: Visible change as specified | Reported Device Performance (Implied by equivalence statement) |
|---|---|---|---|---|---|
| Saturated Steam | 3.0 min ± 5 sec | 121°C (+3/0°C) | Acceptable result | Unacceptable result | Met: No change / Markedly different from specified color change (yellow remains yellow) |
| Saturated Steam | 10.0 min 0/-5 sec | 121°C (+3/0°C) | Unacceptable result | Acceptable result | Met: Visible change to dark brown/black |
| Saturated Steam | 20 sec | 134°C (+3/0°C) | Acceptable result | Unacceptable result | Met: No change / Markedly different from specified color change (yellow remains yellow) |
| Saturated Steam | 0.5 min ± 5 sec | 134°C (+3/0°C) | Acceptable result | Unacceptable result | Met: No change / Markedly different from specified color change (yellow remains yellow) |
| Saturated Steam | 2 min +5/0 sec | 134°C (+3/0°C) | Unacceptable result | Acceptable result | Met: Visible change to dark brown/black |
| Dry Heat | 30 min ± 1 min | 140°C (+2/0°C) | Acceptable result | Unacceptable result | Met: No change / Markedly different from specified color change (yellow remains yellow) |
2. Sample Size Used for the Test Set and Data Provenance
The document states that testing was performed using "multiple lots of NAMSA Chemical Process Indicator Strip for Steam." However, it does not specify the exact sample size for the test set (number of strips from each lot) nor the country of origin of the data. The studies are prospective in nature, as they involve testing the device under controlled conditions.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not explicitly state the number of experts used or their qualifications for evaluating the color changes. Given the nature of a chemical indicator, the "ground truth" for a color change is typically determined by visual observation against a known standard or a reference indicator by trained personnel. It is inferred that the evaluation was performed by qualified personnel involved in the testing, likely those trained in quality control or laboratory procedures for medical device sterility indicators.
4. Adjudication Method for the Test Set
The document does not describe a specific adjudication method (like 2+1 or 3+1). The nature of the test (color change) implies a direct observation against a pass/fail criterion. It's likely that a single observer or
an internal quality control process determined the outcome.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No, a Multi-Reader, Multi-Case (MRMC) comparative effectiveness study was not conducted. This type of study is relevant for diagnostic devices where human interpretation of images or data is involved, often with an AI assist. The NAMSA Chemical Process Indicator Strip is a simple chemical indicator with a direct visual color change, not an AI-driven diagnostic tool. Therefore, the question of human readers improving with AI assistance is not applicable.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
No, a standalone algorithm-only performance study was not done. This device is a passive chemical indicator that relies on a visual color change in response to sterilization conditions, not an algorithm.
7. The Type of Ground Truth Used
The ground truth used for this device is based on pre-defined physical and chemical changes as specified by the manufacturer and validated against the ANSI/AAMI/ISO 11140-1:2005 standard. The "ground truth" is the expected behavior (color change or no change) of the indicator when subjected to specific time and temperature intervals under saturated steam or dry heat conditions. This is a direct physical measurement/observation against established criteria.
8. The Sample Size for the Training Set
The document does not specify a separate "training set" as typically understood in machine learning. For chemical indicators, the "training" analogous to development involves:
- Developing the indicating ink (NAMSA formulation SSI-10-YBI)
- Formulating the design (substrate, ink application, over-laminate)
- Testing numerous iterations during the R&D phase to achieve the desired performance characteristics (i.e., the correct color change at the specified parameters and no change outside those parameters).
The document states the "Indicating Ink was developed and validated for compliance with ANSI/AAMI/ISO 11140-1:2005 guideline," implying an iterative development and testing process.
9. How the Ground Truth for the Training Set Was Established
As there isn't a "training set" in the machine learning sense, the "ground truth" for the development and validation of the indicating ink and device design would have been established through:
- Reference Standards: Adherence to the critical parameters and performance requirements outlined in the ANSI/AAMI/ISO 11140-1:2005 standard, which defines what constitutes a "visible change" and "no change" for a Class 1 process indicator.
- Controlled Laboratory Conditions: Exposing prototype indicators to precisely controlled steam sterilization cycles (time, temperature, saturated steam) and dry heat conditions in a laboratory setting.
- Visual Assessment: Comparing the resulting color changes (or lack thereof) against the predetermined "acceptable" and "unacceptable" results as per the standard for each test condition. This iterative process allows for refinement of the ink formulation and device composition until the desired performance is consistently achieved.
§ 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).