K Number
K073157
Date Cleared
2007-12-07

(29 days)

Product Code
Regulation Number
862.1600
Panel
CH
Reference & Predicate Devices
Predicate For
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

For in vitro diagnostic use only. VITROS K* Slides quantitatively measure potassium (K+) concentration in serum, plasma, and urine. Potassium measurements are used to monitor electrolyte balance in the diagnosis and treatment of diseases and conditions characterized by low or high blood potassium levels.

For in vitro diagnostic use only. VITROS Calibrator Kit 2 is used to calibrate the VITROS Chemistry Systems for the quantitative measurement of CHOL, CT, ECO2, HDLC, K*, Na*, and TRIG.

Device Description

The VITROS K assay is performed using the VITROS Chemistry Products K Slide and the VITROS Chemistry Products Calibrator Kit 2 on the VITROS Chemistry Systems. The VITROS K* Slide is a multilayered, analytical element coated on a polyester support that uses direct potentiometry for measurement of ionic potassium. All reactions necessary for a single quantitative measurement of potassium take place within the multi-lavered analytical element of a VITROS Chemistry Products K*slide. The slide consists of two ion-selective electrodes, each containing valinomycin (an ionophore for potassium), a reference layer, and a silver layer and a silver chloride layer coated on a polyester support.

VITROS Chemistry Products K* Slides use ion-selectrodes for potentiometric measurements of ionic potassium. Ionic potassium determinations are made by simultaneously depositing 10 uL each of a reference fluid and a sample fluid on separate halves of the VITROS Chemistry Products K* slide. The electrode receiving the reference fluid is identified as the reference electrode. A paper bridge connects the reference electrode and the indicator electrode, which receives the sample fluid. A stable liquid junction between the two fluids is formed in the paper bridge in approximately 20 seconds. The potassium ions in the tested reference and sample fluids migrate to the silver/ silver chloride layers and establish equilibrium.

After a two minute incubation period, the electrometer in the VITROS Chemistry System measures the potential difference between the reference and indicator electrodes. Each electrode responds to the activity of potassium ions in the respective fluids to produce a potential for the concentration cell. The VITROS Chemistry System's microcomputer uses this measurement and the stored calibration parameters to determine the concentration value of the potassium ion in the sample fluid. The test result is reported in millimoles per liter (mmol/L).

VITROS Chemistry Products Calibrator Kit 2 contains four levels of Iyophilized standards with corresponding diluents. The standards are prepared from processed bovine serum to which bovine cholesterol, chicken egg yolk, inorganic salts, electrolytes, buffers, stabilizers, and preservatives have been added. The companion diluents are prepared from processed water to which inorganic salts have been added. In addition. Calibrator 4 Diluent contains 0.5 M diethylaminoethanol and 0.01 M (ethylenedinitrilo) tetraacetic acid.

The VITROS System and reagents are designed specifically for use with the VITROS Chemistry Products range of products.

AI/ML Overview

The provided text describes a 510(k) submission for VITROS Chemistry Products K+ Slides (modified) and VITROS Chemistry Products Calibrator Kit 2. The submission aims to demonstrate substantial equivalence to a predicate device.

Here's an analysis of the acceptance criteria and the study proving the device meets them, based on the provided text:

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

The document does not explicitly present specific numerical acceptance criteria (e.g., a specific correlation coefficient, bias limit, or precision target) in a table format. Instead, the "acceptance criterion" appears to be demonstrating substantial equivalence to the predicate device in terms of performance.

The "reported device performance" is summarized in a qualitative statement:

Acceptance CriterionReported Device Performance
Substantial Equivalence to Predicate Device"Equivalence was demonstrated using manufactured slides along with patient and quality control samples with measured potassium values spanning the assay range."

Further details about the performance would typically be found in the full submission, but this summary only provides this high-level statement. The "List of VITROS Chemistry Products K*Slide Characteristics: Comparison to Predicate Device" (Table 1 on page 3) highlights that the intended use, fundamental scientific technology, sample type, and reactive ingredients per cm² are unchanged, which are key aspects supporting equivalence for this type of device.

2. Sample size used for the test set and the data provenance

The document states: "Equivalence was demonstrated using manufactured slides along with patient and quality control samples with measured potassium values spanning the assay range."
However, the exact sample size (number of patient and quality control samples) is not specified in the provided summary.
The data provenance (e.g., country of origin, retrospective or prospective) is also not specified.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

This information is not provided in the document. For an in vitro diagnostic device measuring potassium concentration, "ground truth" would typically refer to the results obtained from a reference method or a well-established, previously cleared device, not human expert interpretation.

4. Adjudication method for the test set

This is not applicable as the device is for quantitative measurement of potassium, and its performance is assessed against a predicate device or reference method, not through human interpretation requiring adjudication.

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

An MRMC study is not applicable to this device. This is an in vitro diagnostic device for quantitative chemical analysis, not an AI-assisted diagnostic imaging or interpretation tool involving human readers.

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

This refers to the performance of the device itself (the VITROS Chemistry Products K+ Slides and Calibrator Kit 2 combination) without human interpretation in the results generation. Given the nature of a chemical analyzer, the assay output is the standalone performance. The document implies this by stating: "Equivalence was demonstrated using manufactured slides along with patient and quality control samples with measured potassium values spanning the assay range." The performance of the system directly outputs the potassium concentration.

7. The type of ground truth used

For this type of in vitro diagnostic device, the "ground truth" would likely be established using a reference method or by comparison to the predicate device's measurements on the same samples. The document states that "Equivalence was demonstrated using manufactured slides along with patient and quality control samples with measured potassium values spanning the assay range," implying comparison against established values for these samples. The specific method used to establish these "measured potassium values" is not detailed, but it would typically be a highly accurate and precise method.

8. The sample size for the training set

This information is not provided in the summary. For an IVD device like this, "training set" might refer to data used during the development and optimization of the assay and manufacturing process, rather than a distinct dataset for machine learning model training.

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

This information is not provided in the summary. Similar to point 7, if a "training set" was used (e.g., for method development), the ground truth would likely be established via reference methods or highly characterized samples.

§ 862.1600 Potassium test system.

(a)
Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte balance in the diagnosis and treatment of diseases conditions characterized by low or high blood potassium levels.(b)
Classification. Class II.