Search Results

Chronos® is indicated for use in a healthcare environment to achieve a high-level disinfection of surfaces of external, transvaginal, and transrectal ultrasound probes that do not contain lumens and that do not contain indentations or channels that are deeper than their widths.

The Germitec Chronos® device is intended to provide Ultraviolet C (UV-C) chemical-free highlevel disinfection (HLD) of ultrasound probes within an enclosed disinfection chamber. As defined in FDA Guidance - Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling, found at https://www.fda.gov/media/80265/download, HLD is a lethal process utilizing a sterilant under less than sterilizing conditions. The process kills all forms of microbial life except for large numbers of bacterial spores. The subject device is intended for use in health care facilities by trained personnel. The Chronos® is an automated medical device consisting of a sealed disinfection chamber, incorporating multiple UV-C lamps and reflective walls. UV-C dose is identified as the only critical determinant of the effectiveness of the disinfection cycle.

The software is used to determine achievement of the disinfection total dose and acceptance of the automated HLD cycle. The total dose delivered to the surface of each ultrasound probe undergoing. the disinfection process is continuously monitored by two optical sensors, UV-C sensitive photodiodes. The control system continuously takes readings from the sensors, tracks progress of the ongoing disinfection cycle, and terminates the disinfection cycle when the cycle-controlling photodiodes indicate that the pre-defined UV-C dose has been achieved. Additionally, the device utilizes an independent cycle monitoring step through the use of a third UV-C photodiode. This independent probe is used to verify that the pre-defined UV-C HLD dose has been delivered.

Onto each ultrasound probe for which compatibility has been validated, a ring is placed onto the ultrasound cable. This ring is used to set the probe into the proper position within the chamber, as well as to include an identifier barcode. This barcode is read by the Chronos® software, and provides identification of both the appropriate disinfection dose as well as traceability for the ultrasound probe undergoing disinfection. The encoding of the barcode to each specific probe model and installation of the ring on each probe can only be performed by an authorized service representative from Germitec.

Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:

Important Note: The provided text describes the regulatory information, device description, and a summary of various bench and in-use studies. It details what performance characteristics were tested and what standards were met but does not provide specific numerical acceptance criteria for each test or the precise quantitative results achieved (e.g., exact log reduction numbers for all microorganisms, specific UV-C dose levels, or exact exposure times). It states that the device "can reliably and consistently achieve a > 6 log reduction" for simulated use and that "results support the determination of microbicidal potency." This indicates the device met the implicit criteria for HLD.

1. Acceptance Criteria and Reported Device Performance

Study Details:

2. Sample size used for the test set and the data provenance:

   • Simulated Use Testing: Not explicitly stated as a numerical sample size of probes per se, but conducted "over a range of worst-case ultrasound probes," with "Representative transvaginal and transrectal (mucous membrane contacting), and external (skin contacting) ultrasound probes" selected for their geometric complexity. For each probe, "three worst-case locations were identified."
   • In-Use Testing: Not explicitly stated as a numerical sample size. Used "Ultrasound probes used in a clinical setting." Transvaginal, transrectal, and external probes were used.
   • Potency Testing: The number of organisms challenged for each microbicidal activity is listed (e.g., 3 for sporicidal, 5 for bactericidal, etc.).
   • Data Provenance: The text states the sponsor is Germitec, located in Bordeaux, France. The studies appear to be retrospective bench studies and prospective in-use studies conducted by the sponsor to validate the device's performance. No specific information about varying countries of origin for the data is provided; it's implicit the data originates from Germitec's testing.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • The document does not explicitly state the number or qualifications of experts used to establish a "ground truth" for the test sets in the traditional sense of clinical interpretations.
   • For the performance testing, the "ground truth" is established by laboratory methods of microbial reduction, minimum effective UV-C dose, and adherence to engineering/safety standards. The experts involved would be microbiologists, engineers, and quality assurance personnel conducting these validated tests, following established protocols (e.g., those from the FDA and IEC).

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

   • This concept (e.g., 2+1, 3+1 adjudication for conflicting diagnoses) is typically applicable to studies involving human interpretation of medical images or clinical decisions where consensus is needed.
   • For the type of bench and in-use performance testing described here (microbial reduction, dose measurement, safety checks), an adjudication method is not applicable. The "ground truth" is determined by objective, measurable outcomes using validated laboratory and engineering techniques, not subjective interpretations requiring multiple expert opinions for consensus.

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, an MRMC comparative effectiveness study was not done.
   • This device is an automated disinfection chamber, not an AI-powered diagnostic or interpretive tool that assists human "readers." Therefore, a study assessing how human readers improve with AI assistance is not relevant to this product.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:

   • Yes, the primary performance studies are essentially standalone. The device itself is an automated system.
   • The "performance testing" (potency, simulated use, optical verification, independent cycle monitoring, etc.) quantifies the device's ability to achieve HLD without human intervention during the disinfection cycle. The software controls the process and determines success or failure based on sensor readings and programmed parameters. While human operators initiate the cycle and load/unload probes, the disinfection itself is fully automated and "algorithm only."

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

   • Microbiological Ground Truth: For the efficacy studies (potency, simulated use, in-use), the ground truth is established by quantitative microbiological reduction. This involves culturing and counting microorganisms before and after disinfection to determine log reduction, against pre-defined thresholds for High-Level Disinfection.
   • Physical/Engineering Ground Truth: For aspects like UV-C dose delivery, safety features (leakage, interlock), temperature control, and electrical/EMC, the ground truth is based on direct physical measurements and adherence to established engineering standards (e.g., IEC standards, pre-defined UV-C doses like the Minimum Effective Dose - MED).

8. The sample size for the training set:

   • The document does not explicitly describe a "training set" in the context of machine learning for an AI algorithm that would be trained on a dataset.
   • While the device has software, its function is largely control, monitoring, and verification based on pre-programmed parameters and sensor feedback, not a learning algorithm that would require a distinct training set in the AI sense.
   • The "training" of the system would be its initial design, programming, and rigorous testing against engineering specifications and biological standards.

9. How the ground truth for the training set was established:

   • As there is no explicitly defined "training set" for an AI model, this question is not directly applicable in the AI sense.
   • If one were to consider the "ground truth" that guided the design and programming of the device's control system and its internal thresholds (e.g., what constitutes an HLD cycle, the required UV-C dose), this ground truth would have been established through:
     • Microbiological research and industry standards for High-Level Disinfection.
     • Experimental determination of UV-C resistance of various microorganisms.
     • Optical simulations and empirical measurements to understand UV-C dose distribution within the chamber and on different probe geometries.
     • Adherence to relevant medical device standards (e.g., IEC standards for safety, FDA guidance for reprocessing).

Ask a specific question about this device