(410 days)
Wunder Pregnancy Test is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin (hCG) in human urine. The device is visually read as an aid for the early detection of pregnancy and intended for in vitro single use. This test is intended for prescription use including at point-of-care sites.
Wunder Pregnancy Test is a single-use qualitative immunochromatic lateral flow device intended to detect human chorionic gonadotropin (hCG) in urine to help in the early detection of pregnancy. The device is visually read and intended for prescription use. Wunder Pregnancy Test is provided in a cassette format. A pipette is included for use with the device. The operator utilizes the included pipette to collect a sample of urine specimen to be tested from a sample cup. The operator then dispenses the urine specimen into the round sample well of the device. An absorbent, nitrocellulose membrane strip is incorporated in the sample well into the rectangular window where the results are read. In the results window, there are two band regions on the membrane strip, a test band and a control band. The test band region is pre-coated with Goat anti-a hCG antibodies. Goat anti-β monoclonal antibodies are placed on the membrane between the test band and the sample well. During the test, the urine sample is allowed to migrate upward and hydrate the anti-β monoclonal antibodies. The mixture then migrates along the membrane by capillary action to the immobilized Goat anti-α hCG antibodies in the test band region. In the presence of hCG in the urine, the anti-ß monoclonal antibodies bind with the hCG ß unit antigen and moves with the sample urine fluid by capillary action along the membrane. As the solution reaches the test band, the antibody hCG ß-unit antigen complex becomes linked to the pre-coated Goat anti-a hCG antibodies to form a visible precipitate that can be seen as a color line at the test band. Therefore, the formation of a visible color line on the test band region indicates the urine sample has tested positive for hCG. In the absence of hCG in the urine, the anti-ß monoclonal antibodies bypass the pre-coated Goat anti-q hCG antibodies in the test region without forming a visible precipitate. As a result, the absence of a visible color line in the test band region indicates the urine sample tested is negative for hCG. The distal control band region is pre-coated with Goat anti Mouse IgG. If there is sufficient urine volume, the anti-ß antibodies will migrate by capillary action to the control region. The anti-ß antibodies will bind with the Goat anti Mouse IgG and precipitate to form a color line. This antigen-antibody reaction at the control line ensures that the test is performed properly and should always be seen as a visible line duringtesting. The presence of this color band in the control region serves as verification that sufficient urine volume has been added and that proper flow was obtained. In conclusion, a valid positive urine sample produces two distinct color bands. A valid negative sample produces only one color band in the control zone.
Here's an analysis of the acceptance criteria and study details for the "Wunder Pregnancy Test" based on the provided 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Method Comparison | High agreement with predicate device | 100% positive agreement (69/69), 100% negative agreement (31/31) with predicate device (dBest Pregnancy Test) for 100 clinical urine samples. Overall >99% agreement. |
| Sensitivity (Cut-off) | Accurate detection at the established cut-off | 100% agreement (60/0) at 25 mIU/mL hCG. |
| Specificity | No interference from common hormones (hLH, hFSH, hTSH) | No interference observed when testing hCG with hLH (500 mlU/mL), hFSH (1000mlU/mL), and hTSH (1000 µlU/mL) in urine samples containing 0 and 25 mlU/mL hCG. |
| Interference (hCG beta-core fragment) | Correct results at or below a specified concentration | Correct results obtained in the presence of hCG beta-core fragment at a concentration equal to or less than 250,000 pmol/L. False negative occurred at concentrations in excess of 250,000 pmol/L. |
| Interference (Hook Effect) | Correct results at or below a specified high hCG concentration | Correct results obtained when testing urine samples with hCG concentrations equal to 1,000,000 mlU/mL. False negative occurred at concentrations in excess of 1,000,000 mlU/mL. |
| Interference (Endogenous/Exogenous Substances) | No interference from a list of common substances | No interference observed from various substances (Acetaminophen, Acetylsalicylic acid, Atropine, L-Ascorbic acid, Caffeine, Salicylic acid, Ampicillin, Glucose, Hemoglobin, Benzoylecgonine, Albumin, Bilirubin, Ethanol) at specified concentrations. Urine specific gravity (1.000-1.030) and urine pH (3-9) also did not interfere. |
2. Sample Size Used for the Test Set and Data Provenance
- Method Comparison Study: 100 female patient urine samples. Data provenance is implied to be prospective and clinical, as samples were "collected and tested at three point of care locations." The country of origin is not explicitly stated.
- Sensitivity Study: 60 samples per hCG concentration level, for a total of 360 samples (60 samples x 6 concentrations: 0, 12.5, 20, 25, 37.5, 50, 100 mlU/mL - though the table only lists 7 concentrations, the summary states 60 samples per level). These were "urine samples from nonpregnant subjects were spiked with hCG," so this is a contrived, laboratory-based test set. Data provenance is not specified for country.
- Specificity, Interference (hCG beta-core fragment, Hook effect, Endogenous/Exogenous Substances): The sample sizes for these studies are not explicitly stated, but it implies multiple tests were conducted for each condition. These were also laboratory-based studies using spiked samples, not clinical patient samples for the interference parts.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- For Method Comparison: The ground truth for the 100 clinical samples was established by the predicate device (dBest Pregnancy Test). No human experts are explicitly mentioned as establishing a separate ground truth. The results of the Wunder Pregnancy Test were compared against the predicate device's results.
- For Sensitivity, Specificity, and Interference Studies: The ground truth was based on the known, spiked concentrations of hCG or other substances. No human experts were involved in establishing this ground truth, as it was chemically determined.
4. Adjudication Method for the Test Set
- For Method Comparison: No adjudication method is explicitly stated. The comparison was directly between the Wunder Pregnancy Test results and the predicate device's results. It's implied that the predicate device's result served as the "truth" for comparison.
- For other studies: Not applicable, as ground truth was based on known chemical concentrations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not reported. The studies focused on the performance of the device itself (standalone) or its agreement with a predicate device. There is no mention of human readers improving with or without AI assistance, as this is a visually read qualitative immunoassay, not an AI-assisted diagnostic tool.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the studies reported are essentially standalone performance studies for the device. The "Wunder Pregnancy Test" is a visually read device, meaning its "performance" is its intrinsic ability to produce a correct visual output based on the presence or absence of hCG. The performance results (sensitivity, specificity, agreement with predicate) are for the device itself. While a human reads the result, the performance metrics evaluate the device's ability to generate the correct visual signal.
7. The Type of Ground Truth Used
- Method Comparison: The ground truth was implicitly the result of the legally marketed predicate device (dBest Pregnancy Test) for the 100 clinical samples.
- Sensitivity, Specificity, Intervention Studies: The ground truth was based on known, controlled concentrations of hCG or other substances in laboratory-prepared (spiked) urine samples. This can be considered a form of analytical truth based on controlled experimental conditions.
8. The Sample Size for the Training Set
This information is not provided. The 510(k) summary describes performance testing for submission, not the development or training of the device. Given that this is a lateral flow immunoassay not an AI/ML device, a "training set" in the computational sense does not apply. The device's biological components (antibodies, etc.) are developed and manufactured, not "trained" on data.
9. How the Ground Truth for the Training Set Was Established
As stated above, this is not applicable as the device is not an AI/ML model requiring a training set with established ground truth in that context. Its "training" would be the scientific and engineering development, optimization, and manufacturing processes of the immunoassay itself.
§ 862.1155 Human chorionic gonadotropin (HCG) test system.
(a)
Human chorionic gonadotropin (HCG) test system intended for the early detection of pregnancy —(1)Identification. A human chorionic gonadotropin (HCG) test system is a device intended for the early detection of pregnancy is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class II.(b)
Human chorionic gonadotropin (HCG) test system intended for any uses other than early detection of pregnancy —(1)Identification. A human chorionic goadotropin (HCG) test system is a device intended for any uses other than early detection of pregnancy (such as an aid in the diagnosis, prognosis, and management of treatment of persons with certain tumors or carcinomas) is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class III.(3)
Date PMA or notice of completion of a PDP is required. As of the enactment date of the amendments, May 28, 1976, an approval under section 515 of the act is required before the device described in paragraph (b)(1) may be commercially distributed. See § 862.3.