(371 days)
The MDU/Rx™ medical model is an ultraviolet (UV) air purifying device intended for the reduction of bacteria and the MS2 and Phi-X174 virus in air in medical facilities. The MDU/Rx"" medical device is non sterile.
The MDU/Rx" device purifies and sanitizes air by circulating ambient air through a filter into a chamber equipped with two ultraviolet (UV) lights (also called optics) with wavelengths in the range between ~100-285 nm, which encompasses the range of light called UV-C, as described in the general system design in Figure E-1.
The provided text describes the Odorox® MDU/Rx™ medical device, an ultraviolet (UV) air purifier. While the document details the device's mechanism, safety testing, and some performance claims, it does not provide a clear table of acceptance criteria nor a comprehensive study demonstrating direct compliance. Instead, it relies on substantial equivalence to predicate devices and performance claims supported by a single test.
Based on the information provided, here's an attempt to answer your questions to the best of my ability, highlighting where information is missing or inferred:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state "acceptance criteria" in a formal, quantifiable table. However, it claims intended performance. Based on the "Performance" and "MDU/Rx™ Device Effectiveness as an Air Sanitizer" sections, we can infer the claimed performance, though not formal acceptance criteria.
| Performance Metric | Claimed Performance (Inferred) |
|---|---|
| Bacteria Reduction | High kill rates of 4-5 log reduction of airborne bacteria from initial concentrations of 6-8 log CFU/cu ft. |
| MS2 and Phi-X174 Virus Reduction | High kill rates of 4-5 log reduction of airborne virus from initial concentrations of 6-8 log CFU/cu ft. |
| Kill Rate Time | 4 log or greater kill rate for all organisms tested within two hours. |
| Ozone Levels | Below 50 ppb in typical, normally ventilated treatment areas. Steady state of ~19 ppb (smaller chamber), ~14 ppb (larger chamber). |
| Carbon Monoxide Levels | Not detected above baseline levels. |
| Formaldehyde, Acetaldehyde, Other Aldehydes | Remained at or marginally above background concentrations. |
| Oxidized Volatile Organic Compounds (VOC) | No significant concentrations formed. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Test Set Sample Size: For the microbial efficacy testing, the document states: "Kill rates were measured in triplicate". This implies 3 replicates for each organism tested.
- Data Provenance: The microbial efficacy testing was performed by "Aerosol Research and Engineering Laboratories (ARE, Overland Park, Kansas)," which is in the USA. The study was likely prospective as it involved aerosolizing microorganisms in a controlled chamber for testing.
- Ozone and By-product Testing: Conducted by "Columbia Analytical Services (Simi Valley, CA)" in the USA, also likely prospective with hourly interval sampling. Additional ozone measurements were conducted by HGI (the manufacturer) in various treatment areas.
3. 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)
The concept of "experts establishing ground truth" as you'd find in diagnostic AI studies (e.g., radiologists) is not applicable here. This device performs a physical function (air purification). The "ground truth" for its performance is established through direct laboratory measurements of microbial count reduction and chemical concentrations. The experts involved would be the scientists and technicians at Aerosol Research and Engineering Laboratories and Columbia Analytical Services, who are presumed to be qualified in microbiology, aerosol science, and analytical chemistry, respectively. Their specific qualifications are not detailed in the document.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. This study does not involve human interpretation or subjective assessments that would require an adjudication method like 2+1 or 3+1. The results are quantitative measurements from laboratory tests.
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
Not applicable. This is not a diagnostic device involving human readers or AI assistance in interpretation. It's an air purification device. Therefore, no MRMC study was conducted.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, effectively. The performance testing described (microbial kill rates, ozone, and by-product measurements) represents the standalone performance of the Odorox® MDU/Rx™ device without any human "in the loop" interaction beyond operating the device as intended. The efficacy is measured directly by its physical effect on the air.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The ground truth used for this device's performance is direct laboratory measurement and quantification of:
- Reduction in viable airborne microorganisms (bacteria and viruses) post-treatment.
- Concentrations of chemical by-products (ozone, CO, aldehydes, VOCs) in the air post-treatment.
Essentially, it's empirical measurement of the device's physical effect on the air.
8. The sample size for the training set
Not applicable. This device is a physical air purifier, not a software algorithm that requires a training set (e.g., for machine learning). The document does not describe any machine learning component of the device.
9. How the ground truth for the training set was established
Not applicable. As there is no training set for a machine learning algorithm, there is no ground truth to establish for such a set.
§ 880.6500 Medical ultraviolet air purifier.
(a)
Identification. A medical ultraviolet air purifier is a device intended for medical purposes that is used to destroy bacteria in the air by exposure to ultraviolet radiation.(b)
Classification. Class II (performance standards).