(14 days)
For in vitro diagnostic use only.
VITROS CREA Slides quantitatively measure creatinine (CREA) concentration in serum, plasma, and urine.
A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.
For in vitro diagnostic use only.
VITROS Calibrator Kit 1 is used to calibrate VITROS Chemistry Systems for the quantitative measurement of BUN/UREA, Ca, CREA, GLU, LAC, LI, Mg, PHOS, SALI, THEO, and URIC.
The VITROS CREA assay is performed using the VITROS Chemistry Products CREA Slides, and the VITROS Chemistry Products Calibrator Kit 1 on VITROS Chemistry Systems.
The VITROS CREA Slide is a multilayered, analytical element coated on a polyester support.
A drop of patient sample is deposited on the slide and is evenly distributed by the spreading layer to the underlying layers. Creatinine diffuses to the reagent layer, where it is hydrolyzed to creatine in the rate-determining step. The creatine is converted to sarcosine and urea by creatine amidinohydrolase. The sarcosine, in the presence of sarcosine oxidase, is oxidized to glycine, formaldehyde, and hydrogen peroxide. The final reaction involves the peroxidase-catalyzed oxidation of a leuco dye to produce a colored product.
Following addition of the sample, the slide is incubated. During the initial reaction phase, endogenous creatine in the sample is oxidized. The resulting change in reflection density is measured at 2 time points.
Once a calibration has been performed for each slide lot. creatinine concentration in unknown samples can be determined using the softwareresident two-point rate math model and the change in reflectance calculated for each unknown test slide.
VITROS Calibrator Kit 1 contains three levels of lyophilized standards with corresponding diluents. The standards are prepared from processed bovine serum to which organic analytes, electrolytes, stabilizers, and preservatives have been added. The diluents are prepared from processed water to which inorganic salts have been added. Once reconstituted, the standards are used to calibrate VITROS Chemistry Systems for the quantitative measurement of creatinine in serum, plasma and urine.
Calibration of the VITROS CREA assay requires the use of all three of the calibrator levels (bottles 1, 2 and 3).
The provided text describes the 510(k) summary for the VITROS Chemistry Products CREA Slides and VITROS Chemistry Products Calibrator Kit 1. It compares a modified device (VITROS CREA assay, modified) to a predicate device (VITROS CREA assay, original). The document focuses on demonstrating substantial equivalence rather than presenting an exhaustive study proving acceptance criteria.
-
Table of Acceptance Criteria and Reported Device Performance:
The document does not explicitly state "acceptance criteria" for the modified device in terms of statistical thresholds (e.g., minimum sensitivity, specificity, or agreement percentages). Instead, it relies on demonstrating substantial equivalence to a cleared predicate device.
The comparison table provided in the 510(k) summary (page 2, "Table 1 List of Assay Characteristics: Comparison to Predicate Device") highlights similarities and minor differences in device characteristics. The "reported device performance" is essentially that these characteristics are sufficiently similar to the predicate device.
Device Characteristic Acceptance Criteria (Predicate) Reported Device Performance (Modified) Intended Use For in vitro diagnostic use only. VITROS CREA Slides quantitatively measure creatinine (CREA) concentration in serum, plasma, and urine. VITROS Calibrator Kit 1 calibrate VITROS Chemistry Systems for quantitative measurement of BUN/UREA, Ca, CREA, GLU, LAC, Li, Mg, PHOS, SALI, THEO, and URIC. No change (Identical to predicate) Calibration traceability Traceable to Certified NIST (National Institute of Standards and Technology) Reference Material SRM® (Standard Reference Material) 914a. The values assigned to the VITROS Chemistry Products Calibrator Kit 1 for Creatinine are traceable to a Gas Chromatography Isotope Dilution Mass Spectrometry (GC/IDMS) method and NIST SRM®914, creatinine standard reference material. (Slight update in method description but still traceable to NIST) Reference Interval (Serum) Males: 0.8 – 1.5 mg/dL; Females: 0.7 – 1.2 mg/dL Males: 0.7 – 1.3 mg/dL; Females: 0.6 – 1.0 mg/dL (Slightly different ranges, but within clinical acceptability) Reference Interval (Urine, 24 hr) 800 – 2800 mg/day (Male and Female) Males: 1000 - 2000 mg/day; Females: 800 - 1800 mg/day (More specific breakdown, still within clinical acceptability) Reportable range (Serum) 0.05 – 14.0 mg/dL No Change (Identical to predicate) Reportable range (Urine) 1.05 – 346.5 mg/dL (after multiplying by a dilution factor of 21) 1.2 – 346.5 mg/dL (after multiplying by a dilution factor of 21) (Slight difference in lower limit, but likely within acceptable limits for the clinical context) Sample type Serum, Plasma, Urine No change (Identical to predicate) Basic principle Two-point colorimetric rate No change (Identical to predicate) Instrumentation VITROS Chemistry Systems No change (Identical to predicate) The "study" described is a performance evaluation demonstrating substantial equivalence, rather than meeting pre-defined quantitative acceptance criteria in isolation. The implicit acceptance criterion is that the modified device performs similarly enough to the predicate device that it can be considered equally safe and effective.
-
Sample size used for the test set and data provenance:
The document states: "Equivalence was demonstrated using manufactured reagents along with quality control fluids, proficiency samples and human serum, plasma, and urine samples with measured creatinine values spanning the assay range."- Sample Size: The exact number of human serum, plasma, and urine samples used is not specified in the provided text.
- Data Provenance: The document does not specify the country of origin. It indicates that the samples were "human serum, plasma, and urine samples," implying real-world clinical samples, but does not state if they were retrospective or prospective.
-
Number of experts used to establish the ground truth for the test set and qualifications of those experts:
This information is not provided in the document. For an in vitro diagnostic device measuring a quantitative analyte like creatinine, the "ground truth" would typically be established by a reference method or a highly accurate laboratory assay rather than expert human interpretation of images. -
Adjudication method for the test set:
This information is not applicable/provided. For a quantitative chemical assay, ground truth is typically established by laboratory reference methods, not human adjudication between experts. -
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. This document describes an in vitro diagnostic device for quantitative creatinine measurement, not an AI-assisted diagnostic imaging device or a device involving human readers/interpreters. -
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
This is not applicable in the context of an "algorithm" as typically referred to for AI/imaging. The device itself (the VITROS CREA assay on VITROS Chemistry Systems) operates in a standalone manner to measure creatinine concentrations in samples. Its performance is evaluated directly against predicate devices or reference methods, without human-in-the-loop interaction in the measurement process itself. -
The type of ground truth used:
The ground truth for the calibration traceability section is stated as:- Gas Chromatography Isotope Dilution Mass Spectrometry (GC/IDMS) method.
- NIST SRM®914, creatinine standard reference material.
These are highly accurate analytical methods/standards used to establish the true concentration of creatinine values.
-
The sample size for the training set:
This information is not provided. The concept of a "training set" as understood in machine learning is not directly applicable here. The device is a chemical assay, and its performance is validated through analytical studies on known samples (standards, quality controls, and patient samples spanning the assay range), not by training a machine learning model. -
How the ground truth for the training set was established:
As explained above, the concept of a "training set" for a chemical assay device is different from that in machine learning. The device's calibration curve is established using known calibrator values, which are traceable to GC/IDMS and NIST SRM®914 (as mentioned in point 7). This essentially acts as the "ground truth" for the device's quantitative measurements.
§ 862.1225 Creatinine test system.
(a)
Identification. A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.(b)
Classification. Class II.