(25 days)
Collection, transport, preservation and preparation of stool specimens containing intestinal parasites for microscopic examination
The product contains two conical shaped centrifuge tubes. One tube contains Polyvinyl Alcohol with Mercury and the other 10% Buffered Formalin. A stand is provided to keep the tubes in the upright position. Both tubes have a spoon contained within the tube which is attached to the cap. The cap/spoon is removed and used to obtain a sample of the stool specimen. The sample is placed into the centrifyge tubes and the cap/spoon assembly is securely closed. The collection tubes are shaken causing the mixing balls to disrupt the specimen allowing complete coverage of the specimen with the fixative. The sample in PVA can be used for permanent staining techniques. The tube with the 10% Buffered Formalin also contains an integral filter which separates large debris from the specimen facilitating concentration of the specimen for wet mount examination. The product is contained in a bag labeled with the biohazard symbol which can be used for transport of the tubes containing samples.
The provided document describes the STP™ System-PVA with Mercury, a fixative-preservative for intestinal parasite examination. The purpose of the study was to evaluate the functional performance of this system.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
Based on the "Performance Test Summary," the acceptance criteria and reported performance can be interpreted as follows:
| Acceptance Criteria (Functional Performance for Microscopic Evaluation) | Reported Device Performance |
|---|---|
| For satisfactory functional evaluation, the smear must adhere well to the glass slides after permanent staining. | The summary indicates a "satisfactory functional evaluation" was achieved. While not explicitly stating "adhered well," the conclusion that the system "results in a successful microscopic examination" implies this criterion was met. |
| For satisfactory functional evaluation, the added cells (white blood cells from buffy coat) must be well-fixed. | The summary indicates a "satisfactory functional evaluation" was achieved. The conclusion states the system "results in a successful microscopic examination," which would necessitate well-fixed cells to be observable. |
| For satisfactory functional evaluation, the added cells (white blood cells from buffy coat) must display typical morphology and color when the permanent stains and wet mounts are examined under a microscope. | The summary indicates a "satisfactory functional evaluation" was achieved. The conclusion states the system "results in a successful microscopic examination," which implies that the morphology and color of the cells were typical and allowed for proper identification, akin to how parasitic forms would be identified. |
| Overall: Enables a successful microscopic examination of human stool specimens for parasites. | Conclusion: The STP™ System - PVA with Mercury, when used according to current instructions, results in a successful microscopic examination of human stool specimens for parasites. (This directly addresses and confirms the overall functional performance. The study uses WBCs in lieu of parasites to demonstrate the system's ability to fix and preserve cellular material for subsequent microscopic analysis.) |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size for Test Set: The document does not specify the exact sample size (number of tubes/specimens) used in the performance evaluation. It only states that "Specimens were evaluated at independent clinical laboratories" and that "white blood cells [...] are added to product tubes containing human stool specimens."
- Data Provenance: The document does not explicitly state the country of origin. It mentions "independent clinical laboratories," but their location is not specified. The study appears to be prospective in nature, as it describes a controlled method for evaluating the functional performance of the device.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- The document does not specify the number or qualifications of experts who established the "ground truth" (i.e., evaluated the slides and wet mounts) for the test set. It states that "microscopic evaluation of permanent slides and wet mounts" was performed, but does not detail who conducted these evaluations.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- The document does not describe any adjudication method for the test set. It only states that product function was "evaluated as either satisfactory or unsatisfactory."
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, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study is focused on the functional performance of a fixative-preservative system, not on evaluating human reader performance, AI assistance, or diagnostic accuracy in the context of reader studies.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No, a standalone (algorithm only) performance study was not done. This device is a component of a manual laboratory procedure, and therefore, an "algorithm only" study is not applicable. The evaluation relies on human observation and interpretation of prepared slides.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for evaluating the functional performance appears to be expert microscopic evaluation of prepared slides and wet mounts, based on predefined criteria for "satisfactory" fixation and morphology (i.e., well-fixed cells, typical morphology and color, good smear adherence). It's based on the observable quality of the preserved cellular material. The study explicitly uses white blood cells "in lieu of parasites" to assess the preservation capabilities of the system.
8. The sample size for the training set
- This concept is not applicable to this type of device and study. The STP™ System is a medical device (fixative-preservative), not an AI algorithm that requires a training set.
9. How the ground truth for the training set was established
- This concept is not applicable as there is no training set for this medical device.
§ 866.2900 Microbiological specimen collection and transport device.
(a)
Identification. A microbiological specimen collection and transport device is a specimen collecting chamber intended for medical purposes to preserve the viability or integrity of microorganisms in specimens during storage of specimens after their collection and during their transport from the collecting area to the laboratory. The device may be labeled or otherwise represented as sterile. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I (general controls). The device, when solely intended for use in the collection of concentrated parasites from specimens and transport, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 866.9.