(222 days)
The Bactis 160US is an automated, computer assisted, optically based in vitro diagnostic instrument intended for the rapid detection and enumeration of bacteria in urine specimens. Urine samples are stained, filtered through a membrane, and excited with light of a defined wavelength range so as to produce a distinct fluorescent signal. Using fluorescent microscopy and a CCD camera, the image of the sample is captured. Using digitized image processing, the microscopic images are analyzed and the concentration of bacteria present in the specimen is determined by applying a proprietary software algorithm.
The Bactis 160US is indicated for rapid urine screening for the purpose of determining the occurrence of bacteriuria. Evidence of bacteriuria is an important factor for clinicians to consider in making a diagnosis of urinary tract infection.
The Bactis 160US is based on direct screening of urine using optical image analysis. Thirty (30) ul of well-mixed urine is mixed with fluorescent stains that bind to bacteria and other particles present in the specimen. The stained samples are filtered through a membrane. The dispersed and stained organisms are excited with a filtered lamp to produce a distinct fluorescent signal. Using fluorescence microscopy and a CCD camera the image of the sample is captured. These microscopic images are then analyzed. Using digitized image processing techniques, the bacteria are localized and enumerated, and their concentration is determined. Bacterial concentration for each specimen can be then reported. Alternatively, the concentration can be compared to a predetermined threshold (according to each laboratory's policy) and each urine sample can be categorized according to the infection category of "positive" or "negative". This method provide results within 25 minutes.
The Bactis system is comprised of the following main components:
- Control and Data Management System (CMS) 1.
- Specimen Processor and Analyzer (SP&A) Unit 2.
The urine screening process is controlled and monitored by the operator via the CMS, The CMS is comprised of two PC computers. An optional printer can be used to provide diagnostic reports. In the SP&A Unit, the specimens are processed and analyzed.
Here's a breakdown of the acceptance criteria and study information for the Bactis 160US, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance (Bactis 160US) |
|---|---|
| Sample size | 4561 |
| Threshold CFU/ml | $\ge 10^5$ |
| Sensitivity | 87.5% - 90.2% |
| Specificity | 75% - 86.7% |
| Negative Predictive Value | 96.2% - 97.5% |
Study Details
2. Sample size used for the test set and the data provenance:
- Test Set Sample Size: 4561 random urine specimens.
- Data Provenance: The study was conducted prospectively at two different clinical sites. The specific country of origin is not explicitly stated, but the company is based in Herzliya, Israel.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document implies that the "standard reference methods for detecting bacteriuria" and "standard reference culture procedures" were used as ground truth. It does not specify the number of experts, their qualifications, or if a dedicated panel of experts was involved in establishing the ground truth for the test set.
4. Adjudication method for the test set:
- The document states that the studies were conducted under "double blinded conditions." This implies that those performing the Bactis 160US tests and those interpreting the standard reference methods were unaware of each other's results. However, it does not explicitly mention an adjudication method (like 2+1, 3+1, etc.) in case of discrepancies.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
- No, a multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance was not performed or described. The study compared the device's performance against standard reference cultures.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, the performance data presented is for the Bactis 160US as an automated, computer-assisted system. It reports the algorithm's performance (sensitivity, specificity, NPV) in detecting bacteria in urine specimens against culture results. While an operator loads samples and monitors the process, the analysis itself is automated and driven by the algorithm.
7. The type of ground truth used:
- The ground truth used was standard reference culture methods for detecting bacteriuria. The document also mentions "standard reference procedures such as expanded culture" and assessing "growth inhibitory substances in urine."
8. The sample size for the training set:
- The document does not specify the sample size used for the training set. It only describes the clinical studies conducted for performance validation.
9. How the ground truth for the training set was established:
- This information is not provided in the document. The document focuses on the performance study and its ground truth, not on the development or training of the proprietary software algorithm.
§ 866.2660 Microorganism differentiation and identification device.
(a)
Identification. A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more components, such as differential culture media, biochemical reagents, and paper discs or paper strips impregnated with test reagents, that are usually contained in individual compartments and used to differentiate and identify selected microorganisms. The device aids in the diagnosis of disease.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.