(165 days)
The OcculTech Occult Blood Rapid Test is a card type rapid test and an immunochromatography based in-vitro test designed for qualitative detection of fecal occult blood that can be performed in laboratories or physicians offices. It is useful in determining gastrointestinal bleeding found in a number of gastrointestinal disorders (e.g. diverticulitis, colitis, polyps and colorectal cancer). This device is recommended for use in routine physical examinations, when hospital patients are first admitted, hospital monitoring for bleeding in patients, and screening for colorectal cancer or gastrointestinal bleeding from any source.
The OcculTech Fecal Occult Blood Rapid Test is a colloidal gold enhanced immunoassay for the detection of hemoglobin in human stool. During the assay the specimen stool are absorbed into the sample pad and migrate upwards chromatographically on the membrane by capillary action. The specimen stool extraction containing hemoglobin forms antibody complex with monoclonal antihemoglobin IgG gold colloid conjugate in the conjugate pad. The mixure migrates to nitrocellulose membrane in the test region where other immobilized monoclonal antihemoglobin IgG is present, and then forms a colored sandwich binding (ant-hemoglobin IgG gold colloid-hemoglobin-anti hemoglobin IgG). The OcculTech Fecal Occult Blood Rapid Test is one step test based on the immunochromatography. The test results are visually determined without using any special instrument. It is a simple operation and a number of specimen can be treated in minimal time.
Here's a breakdown of the acceptance criteria and study information for the OcculTech Fecal Occult Blood Rapid Test, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The submission primarily focuses on demonstrating substantial equivalence to a predicate device rather than defining new, explicit acceptance criteria tied to clinical endpoints with specific thresholds. Instead, the performance is reported as agreement with the predicate device or expected results.
| Study Type | Acceptance Criteria (Implicit/Implied) | Reported Device Performance |
|---|---|---|
| Sensitivity (hHb detection) | Detect human hemoglobin (hHb) at levels close to or higher than 50ng/mL. | Can detect hHb at the level close to or higher than 50ng/mL in extraction buffer. |
| Prozone Effect | No interference from prozone effect up to 2000ng hHb/mL. | No interference from prozone effect observed up to 2000ng hHb/mL. |
| Specificity (Cross-reactivity) | 100% agreement with predicate device (Instant-View™) for absence/presence of hHb with other species' hemoglobin. | 100% agreement with predicate device. Negative for other species' Hb when hHb absent. Positive when hHb present. |
| Specificity (Interference) | 100% agreement with predicate device (Instant-View™) regarding tested interfering substances. | 100% agreement with predicate device. Negative for interfering substances when hHb absent. Positive when hHb present. |
| Reproducibility & Repeatability | High agreement with expected results and predicate device. Aim for >95% agreement. | 98% agreement with expected results by three professionals. 99% agreement with expected results from Reference Laboratory. 99% agreement with Instant-View™ Fecal Occult Blood Rapid Test. |
| Specimen Stability | Maintain performance after storage at specific conditions. | Up to 6 months at 4℃ and 24 months at -20℃. |
| Test Strip Stability (after opening) | Maintain performance after opening at room temperature. | Up to 28 days at room temperature. |
2. Sample Sizes Used for the Test Set and Data Provenance
- Sensitivity and Prozone effect: 40 stool extraction samples. The text does not specify the country of origin or whether this was retrospective or prospective data.
- Specificity (Cross-reactivity): Not explicitly stated as a number of samples, but implied to be multiple tests with various animal hemoglobin types.
- Specificity (Interference): Not explicitly stated as a number of samples, but implied to be multiple tests with various interfering substances. Each test was performed as duplicates.
- Reproducibility and Repeatability: The study involved "tests performed by the three professionals" and "results obtained from the Reference Laboratory." The number of "expected results" or cases used for comparison isn't specified, but implies a collection of results against which the performance was measured.
- Training Set: Not specified in the document.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Reproducibility and Repeatability: "three professionals with diverse education backgrounds and work experiences" were involved in performing tests and achieving agreement with "expected results." Their specific qualifications (e.g., medical doctors, lab technicians) or years of experience are not detailed.
- Reference Laboratory: "the Reference Laboratory" provided "expected results," but the number and qualifications of experts within this laboratory are not given.
- Other studies (Sensitivity, Specificity): The ground truth for these studies appears to be based on the known controlled concentrations of human hemoglobin (hHb) or the absence/presence of hHb, rather than expert judgment.
4. Adjudication Method for the Test Set
- The document does not describe a formal adjudication method (e.g., 2+1, 3+1).
- For Reproducibility and Repeatability, it states "the results obtained from the tests performed by the three professionals... agreed 98% with expected results (average)." This suggests a comparison against a predetermined or established "expected result" rather than an adjudication process among the professionals themselves.
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 MRMC comparative effectiveness study was done.
- This device is a rapid diagnostic test, not an AI-powered image analysis or diagnostic tool that assists human readers. Therefore, the concept of human readers improving with AI assistance is not applicable here.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
- This device is a standalone rapid immunochromatography test. The results are "visually determined without using any special instrument." There is no "algorithm" in the modern sense of AI or automated interpretation. The performance reported (sensitivity, specificity, reproducibility) are for the device's standalone operation.
7. The Type of Ground Truth Used
- Sensitivity and Prozone effect: Known concentrations of human hemoglobin (hHb) spiked into a buffer.
- Specificity (Cross-reactivity): Known presence or absence of human hemoglobin and various animal hemoglobins.
- Specificity (Interference): Known presence or absence of human hemoglobin and various interfering substances.
- Reproducibility and Repeatability: "Expected results" which likely refer to the known state of control samples or a pre-established gold standard for the samples tested, possibly determined by reference methods or the predicate device.
8. The Sample Size for the Training Set
- The document does not provide information on a specific "training set" for the device. This type of diagnostic test usually undergoes development and internal validation, but a formal "training set" in the context of machine learning or AI is not applicable. The studies described are performance evaluations.
9. How the Ground Truth for the Training Set was Established
- As no training set is described, the method for establishing its ground truth is also not provided.
§ 864.6550 Occult blood test.
(a)
Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)(b)
Classification. Class II (special controls). A control intended for use with an occult blood test is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.