(239 days)
When affixed to a medical device by a health care provider (user), the HEATmarker™ Time-Temperature Indicator (TTI) is indicated, via a permanent color change, for the purpose of distinguishing between medical devices that have exceeded a selected timetemperature profile of interest to the user from devices that have not exceeded that profile.
The HEATmarker™ TTI monitors the temperature history over time for any medical device to which it is affixed. The TTI can be used to monitor the heat exposure of devices at the unit package level. The TTI is constructed similar to a label that allows it to be permanently affixed to a medical device, or to the medical device packaging.
The visible surface of the TTI contains an area of color-changing ink surrounded by an area of fixed color. The TTI varies in color from start point (light) to end point (dark), defined as the time when the inner, active area reaches the same color as the fixed reference area. TTIs are categorized by the length of time at a specified temperature until end point is reached, for example, 3 months at 5°C.
Here's a breakdown of the acceptance criteria and study information for the HEATmarker™ Time Temperature Indicator, based on the provided 510(k) summary:
Acceptance Criteria and Reported Device Performance
The information provided describes the mechanism of the device and general performance characteristics rather than specific quantitative acceptance criteria or detailed reported performance against those criteria in a table.
The core acceptance criterion for the HEATmarker™ TTI is its ability to change color reliably and predictably in response to a specific time-temperature profile, thereby indicating when a medical device has exceeded that profile.
| Acceptance Criteria (Inferred) | Reported Device Performance (Summary) |
|---|---|
| Prediction of "End Point": The TTI should reliably indicate when a pre-defined "end point" (fixed reference color match) is reached based on cumulative heat exposure. | The TTI varies in color from start (light) to end point (dark), "defined as the time when the inner, active area reaches the same color as the fixed reference area." This indicates its ability to reach a predictable end point. |
| Predictable Color Change: The color change should be predictable when exposed to a given temperature for a specified period of time. | "The HEATmarker™ TTI changes color in a predictable manner when exposed to a given temperature for a specified period of time." |
| Adherence to Arrhenius Relationship: The color change kinetics should follow the Arrhenius relationship for time and temperature. | "HEATmarker™ TTIs have been shown to react according to the Arrhenius relationship with regard to time and temperature. Studies of the polymerization of the substituted diacetylene monomers support this relationship as do more recent studies involving inks made from these monomers." |
| Correlation with External Temperature Monitoring: The TTI's color change should correlate with independently recorded temperature data. | "Emergency Medical personnel have used HEATmarker™ TTIs in a number of studies addressing the possibility of heat abuse to medical devices carried in emergency vehicles. The TTIs changed color in accordance with the Mean Kinetic Temperature recorded on the vehicles using electronic temperature recorders." |
| Ability to Distinguish Profiles: The TTI should effectively distinguish between devices that have or have not been exposed to a specific time and temperature profile. | "As with the predicate device, this allows the TTI to demonstrate that the medical device to which it is affixed has been exposed to a quantity of heat characterized by a specified time-temperature profile." This is also the core of its intended use and indications for use. |
| Comparison to Predicate Device: Performance should be comparable to the predicate device (SteriTec Dry Heat Indicator Labels). | "Both the HEATmarker™ TTI and the predicate device are manufactured utilizing inks that change color in response to exposure to a given temperature for a specified time." The key difference noted is the HEATmarker™ TTI's static reference color vs. the predicate's green to black color change, implying functional equivalence in achieving the indicative purpose. |
Study Information
Based on the provided text, the studies described are non-clinical and focus on the fundamental behavior and validation of the TTI's chemical-physical properties. These are not typical clinical studies involving human patients or complex diagnostic accuracy metrics seen in AI/imaging devices.
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Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Sample Size: Not explicitly stated for any specific "test set." The text mentions "a number of studies" using TTIs in emergency vehicles, but not the quantity of TTIs or vehicles.
- Data Provenance: Not specified. "Emergency Medical personnel" are mentioned, suggesting a healthcare setting, but no country or geographical origin is provided.
- Retrospective or Prospective: Not specified. The study involving emergency vehicles sounds like it could have been prospective field testing.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):
- Not applicable to this type of device. The "ground truth" for the TTI's performance is established by physical measurements (electronic temperature recorders which recorded Mean Kinetic Temperature) and the chemical-physical principles (Arrhenius relationship) governing the ink's reaction. Human experts are not used to establish the "ground truth" for the TTI's color change.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable. Adjudication methods are typically used in studies where human interpretation or consensus is required to establish ground truth or resolve discrepancies. Here, the indicators' color changes are compared against objective temperature recordings and chemical principles.
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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:
- Not applicable. This is not an AI/imaging device, nor does it involve human readers interpreting complex medical cases. The device itself is an indicator.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- This device is a standalone indicator. Its performance is entirely based on the chemical reaction of its ink to temperature and time. The "readout" is a direct visual comparison by a human to a fixed reference color. There is no complex algorithm in the contemporary sense of "AI." The device inherently performs "without human-in-the-loop" in its core function of reacting to temperature, but requires a human to observe and interpret the color change.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- Physical Measurements: For the emergency vehicle studies, the ground truth was the Mean Kinetic Temperature recorded by electronic temperature recorders.
- Physical/Chemical Principles: For the fundamental behavior, the ground truth is the well-established Arrhenius relationship governing reaction rates with temperature, supported by studies on the polymerization of the constituent monomers.
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The sample size for the training set:
- Not explicitly stated. The studies mentioned (polymerization, inks, emergency vehicles) contribute to understanding and possibly "optimizing" the TTI's behavior, but they are not framed as "training sets" in the context of machine learning. The device's design is based on chemical engineering principles, not statistical learning from data.
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How the ground truth for the training set was established:
- Not applicable in the machine learning sense. The foundational understanding and characterization of the TTI's behavior (analogous to "training") would have come from laboratory studies of chemical reactions under controlled temperature and time variations, where the "ground truth" is the precisely controlled temperature and time exposure, and the resulting observed color change. The Arrhenius relationship provides the theoretical framework.
§ 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).