Search Results

The ARK Voriconazole II Assay is a homogeneous enzyme immunoassay intended for the quantitative determination of voriconazole in human serum on automated clinical chemistry analyzers. The measurements obtained are used in monitoring levels of voriconazole to help ensure appropriate therapy. The assay should only be used in conjunction with information available from clinical evaluations and other diagnostic procedures.

ARK Voriconazole II Calibrator is intended for use in calibration of the ARK Voriconazole II Assay.

ARK Voriconazole II Control is an assayed quality control material intended for use in quality control of the ARK Voriconazole II Assay.

Device Description

The ARK Voriconazole II Assay Test System consists of the ARK Voriconazole II Assay, the ARK Voriconazole II Calibrator, and the ARK Voriconazole II Control.

The ARK Voriconazole II Assay consists of:

Reagent R1: rabbit polyclonal antibodies to voriconazole, glucose-6-phosphate, nicotinamide adenine dinucleotide, bovine serum albumin, sodium azide, and stabilizers.
Reagent R2: voriconazole labeled with bacterial G6PDH buffer, bovine serum albumin, sodium azide, and stabilizers.

The ARK Voriconazole II Calibrator has six levels and consists of voriconazole, buffer, bovine serum albumin, and sodium azide.

The ARK Voriconazole II Control has three levels and consists of voriconazole, buffer, bovine serum albumin, and sodium azide.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study details for the ARK Voriconazole II Assay Test System, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are generally implied by the special controls and the types of studies performed, aiming for performance characteristics that make the device fit for its intended use. Specific numerical acceptance criteria were not explicitly stated in all sections (e.g., for precision, rather than a universal requirement, the reported values are provided). However, for interference studies, a clear threshold was defined.

Performance Characteristic	Acceptance Criteria (Implied/Explicit)	Reported Device Performance
Precision (Internal)	Not explicitly stated (demonstrate precision)	Total CV% for controls: LOW (4.9), MID (4.3), HIGH (4.5). Total CV% for human serum: LOW (4.6), MID (4.3), HIGH (4.2). Second internal study Total CV%: LOW (5.9), MID (5.1), HIGH (6.3).
Precision (Multi-Site)	Not explicitly stated (demonstrate precision)	Reproducibility CV% for controls: LOW (6.0), MID (5.5), HIGH (6.5). Reproducibility CV% for human serum: LOW (5.4), MID (5.2), HIGH (5.5).
Linearity/Reportable Range	Claimed measuring range (0.5 to 14.0 ug/mL) supported by regression.	Y = 1.0209 X - 0.0416, R²: 0.9995. Supports range 0.5 to 14.0 ug/mL.
Analytical Recovery	Not explicitly stated (assess recovery).	Ranged from 90.0% to 104.9%.
Traceability	Calibrators traceable to certified standard.	Calibrators traceable to USP Reference Standard.
Detection Limit	LoB, LoD, LoQ determined per CLSI EP17-A2. LoQ bias ≤15% and within-lab precision ≤10%.	LoB = 0.003 ug/mL. LoD = 0.05 ug/mL. LoQ = 0.5 ng/mL (0.0005 ug/mL). Note: The text states 0.5 ng/mL but the linear range is 0.5 ug/mL, implying a discrepancy or typo in the LoQ value in the document. Assuming it meant 0.5 ug/mL for consistency with the linear range.
Analytical Specificity (Endogenous Substances)	Interference considered significant if analytical recovery is outside of ± 10% of initial value.	All reported percentage recoveries for endogenous substances at 1.0 µg/mL and 5.0 µg/mL voriconazole were within 90-110%.
Cross-reactivity (N-oxide Voriconazole)	Data from studies performed to evaluate cross-reactivity.	Non-significant (≤ 3.0%) cross-reactivity observed.
Potentially Co-Administered Medications	Data from interference studies. Interference considered significant if analytical recovery is outside of ± 10% of initial value.	No significant interference observed. All reported percentage recoveries were within the 90-110% range.
Method Comparison (Accuracy)	Data demonstrating accuracy; comparator method not subject to bias.	Passing Bablok regression slope 0.98-0.99 (95% CI covering 1), intercept 0.05-0.08 (95% CI covering 0), R² 0.95-0.97.

2. Sample Size Used for the Test Set and Data Provenance

Precision (Internal Study 1): 160 replicates for each of 3 control levels and 3 human serum pools. Likely internal ARK data.
Precision (Internal Study 2): 120 replicates for each of 3 patient sample pools. Likely internal ARK data.
Precision (Multi-Site Study): 120 replicates for each of 3 control levels and 3 human serum pools across 3 sites (360 total per control/pool level). Data from ARK and two external sites.
Linearity: 11 levels of samples, tested in two runs with three replicates per run. Samples were prepared by dilution of pure voriconazole in pooled human serum.
Analytical Recovery: Serum samples prepared by gravimetric and volumetric addition of pure voriconazole to human serum. Number of samples not explicitly stated but covers 7 concentration points.
Detection Limit Studies:
- LoB: 20 blank patient specimens tested.
- LoD/LoQ: A low concentration pooled serum sample.
Analytical Specificity (Endogenous Substances): Samples with known levels of voriconazole (1 and 5 ug/mL) spiked with interferents. Each sample tested in two runs with three replicates per run.
Cross-reactivity: N-oxide-voriconazole at 5.0 ug/mL and 10.0 µg/mL levels, tested in absence or presence of voriconazole.
Potentially Co-Administered Medications: Samples with known levels of voriconazole (1 and 5 ug/mL) spiked with 58 different medications.
Method Comparison Study: 165 serum specimens. Samples represented a diverse population of in-hospital patients. Tested at 3 study sites. Provenance is prospective in the sense that they are patient samples collected for comparison, likely from the hospitals where the sites were located. Origin (country) not specified.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

Not Applicable. This device is an in-vitro diagnostic test for measuring an analyte (voriconazole concentration) in human serum. The "ground truth" for these studies is established through either:
- Known gravimetric/volumetric preparation of standards (for linearity, recovery, detection limits, interference, cross-reactivity).
- Comparison with a reference method (LC-MS/MS for the method comparison study).
  The concept of "experts" to establish ground truth as typically found in image analysis or clinical diagnosis contexts (e.g., radiologists, pathologists) does not apply here.

4. Adjudication Method for the Test Set

Not Applicable. As explained above, ground truth is established through analytical means or comparison to a reference method, not through human expert 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

Not Applicable. This is an in-vitro diagnostic device for quantitative measurement, not an AI-assisted diagnostic imaging or interpretation device that involves human "readers."

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, this is a standalone device validation. The ARK Voriconazole II Assay Test System is an automated clinical chemistry analyzer-based test. The performance characteristics described are for the device (the assay and analyzer) itself, without human intervention in the measurement process once the sample is loaded. The "algorithm" here is the chemical reaction and spectrophotometric measurement programmed into the analyzer.

7. The Type of Ground Truth Used

Known concentrations: For precision, linearity, analytical recovery, detection limits, endogenous substance interference, cross-reactivity, and co-administered medication interference studies, the "ground truth" was either:
- Gravimetrically/volumetrically prepared samples with known concentrations of voriconazole or interferents.
- Pooled human serum samples with established mean concentrations.
Reference method (LC-MS/MS): For the method comparison study, the validated LC-MS/MS method served as the reference standard for establishing the ground truth concentrations in patient samples.

8. The Sample Size for the Training Set

Not Applicable. This is an in-vitro diagnostic assay based on a homogeneous enzyme immunoassay principle, not a machine learning or AI algorithm that requires a "training set" in the conventional sense. The "training" of the device involves calibration using the provided ARK Voriconazole II Calibrators.

9. How the Ground Truth for the Training Set Was Established

Not Applicable. As above, it's not an AI/ML training set. The "ground truth" for the calibrators (which serve a similar function to training in some contexts, by enabling the device to accurately convert signal into concentration) is established through internal procedures and traceability to a certified USP Reference Standard. The text states: "The ARK Voriconazole II Calibrators are traceable to a certified USP Reference Standard." and "Concentrations of the ARK Voriconazole II Calibrators and Controls are assigned through internal procedures that were reviewed and found to be acceptable."

Ask a Question

Ask a specific question about this device

Page 1 of 1