The FemExam® TestCard™ contains two qualitative, colorimetric tests: a pH test and an amine test. The pH test uses nitrazine yellow to produce a visual color change within two minutes of specimen application, indicating pH less than or greater than 4.7. It includes a positive procedural control and a negative background control. The amine test uses bromocresol green (BCG) and sodium aluminate to produce a visual color change within two minutes of specimen application, indicating the presence of alkali volatilizable amines. It also includes a positive procedural control and a negative background control.

AI/ML Overview

The provided text describes the FemExam® TestCard™, a device with two qualitative, colorimetric tests for vaginal fluid: a pH test and an amine test. The information needed for a comprehensive study description, such as specific acceptance criteria and detailed performance data, sample sizes, and ground truth establishment for training, is not fully available in the provided text. However, based on the given information, here's an attempt to structure the answer:

Device: FemExam® TestCard™ pH and Amine Tests

1. A table of acceptance criteria and the reported device performance

The document does not explicitly state numerical acceptance criteria (e.g., minimum sensitivity, specificity, or agreement percentages). However, it reports statistically significant overall agreement for both tests.

Acceptance Criteria (Implicit)	Reported Device Performance (pH Test)	Reported Device Performance (Amine Test)
Demonstrate "statistically significant overall agreement" with a reference method.	Statistically significant overall agreement with ColorpHast® pH test strip.	Statistically significant overall agreement with the whiff test.
Positive Agreement (Accuracy)	Calculated	Calculated
Negative Agreement (Accuracy)	Calculated	Calculated
Overall Agreement (Accuracy)	Calculated	Calculated

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: Not specified. The document only mentions "a statistically designed clinical study."
Data Provenance: Not specified (e.g., country of origin, retrospective or prospective). It is a clinical study, suggesting prospective data collection, but this is not explicitly stated.

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)

pH Test Ground Truth: The ground truth was established by comparing to a "commercial pH test strip (ColorpHast® pH test strip) routinely used in clinical studies to estimate vaginal fluid pH." No experts are explicitly mentioned for this ground truth.
Amine Test Ground Truth: The ground truth was established by comparing to "the whiff test, an accepted clinical standard for ascertaining volatile vaginal fluid amines." While the whiff test is a clinical standard, the number and qualifications of individuals performing and interpreting the whiff test (who would effectively be establishing ground truth) are not provided.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not specified. The document does not describe any adjudication process for the results of either the FemExam® TestCard™ or the reference methods.

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

This is not applicable to the FemExam® TestCard™. This device is a diagnostic test kit, not an AI assistance tool for human readers. It provides direct qualitative results.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, this was a standalone performance study. The FemExam® TestCard™ itself generates qualitative colorimetric results (blue plus/minus signs against specific backgrounds) that are interpreted directly. There doesn't appear to be a human-in-the-loop interpretation that significantly alters the test's outcome; rather, the test provides a direct result.

7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)

pH Test: A commercial pH test strip (ColorpHast® pH test strip), which serves as a widely accepted clinical reference method for pH estimation.
Amine Test: The whiff test, which is an "accepted clinical standard for ascertaining volatile vaginal fluid amines."

8. The sample size for the training set

Not applicable. The FemExam® TestCard™ is a chemical assay kit, not a machine learning model. Therefore, there is no "training set" in the context of AI/ML.

9. How the ground truth for the training set was established

Not applicable, as there is no training set for this type of device.

Summary

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K962718

Litmus Concepts, Inc. 2981 Copper Road Santa Clara, CA 95051 (408) 245-5525 Attention: Marian B. Buccaturni July 10, 1996

FEB - 7 1997

は

FEMEXAM® TESTCARD™ pH AND AMINE TESTS 510(K) SUMMARY - SAFETY AND EFFECTIVENESS

This summary of 510(k) safety and effectiveness is submitted in accordance with the requirements of SMDA 1990 and 21 CFR Section 807.92. Litmus Concepts, Inc. (LCI) hereby states that it will make available this safety and effectiveness information to any interested persons upon request.

1. Introduction:

The FemExam® TestCard™ contains two qualitative, colorimetric tests for use in the characterization of a vaginal fluid sample: (1) a pH test that differentiates vaginal fluid pH less than pH 4.7 from vaginal fluid pH equal to or greater than pH 4.7; and (2) a test that detects alkali volatilizable amines in vaginal fluid. Elevated vaginal fluid pH (pH 4.7 or higher) and the detection of a fishy odor upon adding 10% potassium hydroxide (KOH) to vaginal fluid represent two of the four Amsel criteria.

2. pH Test:

The FemExam® TestCard™ pH test system contains a traditional colorimetric pH indicator, nitrazine yellow, which produces a visual, geometric color change within two minutes of specimen application. When contacted with a vaginal fluid specimen at or above pH 4.7, the pH test produces a blue plus sign against a greenish-yellow background. When contacted with a vaginal fixid specimen below pH 4.7, the pH test produces a blue minus sign against a greenish-vellow background.

A narrow minus sign across the center of the pH test serves as the positive procedural control and is produced when the pH test is wetted with a vaginal fluid specimen. The positive control contains nitrazine vellow specifically formulated to change color (from greenish-yellow to blue) regardless of whether the pH of the vaginal fluid specimen is normal or elevated. Although the area surrounding the undeveloped plus sign within the pH test circle also contains nitrazine yellow, it is specifically designed not to change color, regardless of whether the pH of the vaginal fluid specimen is normal or elevated, and serves as the negative background control.

3. Amine Test:

The FemExam® TestCard™ amine test system contains a traditional colorimetric pH indicator, bromocresol green (BCG), which produces a visual, geometric color

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change within two minutes of specimen application. When contacted with a vaginal fluid specimen that contains alkali volatilizable amines, the amine test produces a blue plus sign against a vellow background. When contacted with a vaginal fiuid specimen that does not contain alkali volatilizable amine test produces a blue minus sion against a vellow background.

The TestCard™ amine test employs a very thin dried film of BCG in the yellow test circle which is surrounded by a thick black ring covered with a dried alkali, sodium aluminate. The BCG on the yellow amine test circle produces a visual color change (blue plus sign) in response to the pH elevation produced when the BCG is contacted with a vacinal fluid specimen containing amines volatilized by contact with the sodium aluminate on the thick black ring. The TestCard™ amine test detects volatile amines at concentrations above 0.5mM.

A narrow blue minus sign across the center of the TestCard™ amine test serves as the positive procedural control and is produced when the amine test is wetted with a vaginal fluid specimen. The positive control contains BCG specifically formulated to change color (from yellow to blue) regardless of whether the vaginal fluid specimen does or does not contain alkali volatilizable amines. Although the area surrounding the undeveloped plus sign within the test circle also contains BCG, it is specifically designed not to change color upon the addition of the vaginal fluid specimen, regardless of whether it contains alkali volatilized amines, and serves as the negative background control.

4. Performance Characteristics:

The FemExam® TestCard™ pH and amine tests were evaluated in a statistically designed clinical study. The results of the TestCard™ pH test were compared to the results of a commercial pH test strip (ColorpHast® pH test strip) routinely used in clinical studies to estimate vaginal fluid pH. The results of the TestCard™ amine test were compared to the results of the whiff test, an accepted clinical standard for ascertaining volatile vaginal fluid amines. The positive agreement, negative agreement and overall acreement were calculated. The Test exhibited statistically significant overall agreement with the results of the pH test strip. The TestCard™ amine test exhibited statistically significant overall agreement with the results of the whiff test.

Regulation Number and Section

§ 862.1550 Urinary pH (nonquantitative) test system.

(a)
Identification. A urinary pH (nonquantitative) test system is a device intended to estimate the pH of urine. Estimations of pH are used to evaluate the acidity or alkalinity of urine as it relates to numerous renal and metabolic disorders and in the monitoring of patients with certain diets.(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 § 862.9.