(335 days)
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
| Acceptance Criteria Category | Specific Performance Characteristic Tested (as outlined in Special Controls) | Reported Device Performance and Confirmation of Meeting Criteria |
|---|---|---|
| Non-clinical performance testing: | ||
| (i) Resistance testing (hierarchy of resistance to UV radiation using a panel of clinically relevant and UV-resistant microorganisms) | A hierarchy of UV-C resistance was determined. The most resistant microorganism tested was Aspergillus brasiliensis (Trichomaceae family). This indicates the device's efficacy was tested against a range of increasingly resistant microbes to establish its limits and inform subsequent testing. The implication is that the device is effective against organisms less resistant than A. brasiliensis. | |
| (ii) Potency testing (against bacterial spores, vegetative bacteria, mycobacteria, yeast/molds (spores), spore forming molds and virus, demonstrating microbial log reduction appropriate for HLD) | Microbicidal potency testing was conducted for sporicidal, bactericidal, fungicidal, mycobactericidal, and virucidal efficacy against a broad panel of organisms (B. subtilis, B. pumilus, C. sporogenes, D. radiodurans, S. enterica, S. aureus, P. aeruginosa, P. fungorum, M. terrae, M. bovis, M. avium, C. auris, C. albicans, T. mentagrophyte, A. brasiliensis, P. polonicum, Poliovirus Type 1, Adenovirus Type 5, Murine Norovirus, Vaginal Herpes, Polyomavirus, HPV16/HPV18). The documentation provided "support[s] the determination of microbicidal potency for the device," suggesting that the required log reductions for HLD were achieved for these categories. | |
| (iii) Simulated use testing (under worst-case use and device conditions, including challenge microorganism, inoculum, device complexity, exposure dose, and time) | Conducted over a range of worst-case ultrasound probes, demonstrating that the Chronos® can reliably and consistently achieve a > 6 log reduction of Bacillus subtilis. B. subtilis was identified as the most resistant bacterial spore and most appropriate for simulated use. Three worst-case locations on each probe (based on UV-C penetration difficulty) were identified, and a > 6 log microbial reduction was demonstrated for these challenging geometries. This confirms the device's ability to perform under stringent, real-world-simulated conditions to the HLD standard. | |
| (iv) In-use testing (under real-world clinical use conditions) | Performed on clinically used transvaginal, transrectal (with sheath and gel), and external (dry wipe only) probes. "In-Use testing demonstrated the achievement of HLD on these clinical used ultrasound probes." This validates the device's performance in a true clinical setting, accounting for factors like residual soil and clinical handling. | |
| (v) Photobiological safety of lamps/systems (Performance testing) | This refers to the UV-C Leak Test, which demonstrated that UV-C leakage remained |
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