(9 days)
The Vitalab c .- Amylase Reagent Kit is intended for use with the Vitalab Selectra Analyzer as a system for the quantitative determination of a-amylase in serum and plasma. Amylase results may be used for the diagnosis and treatment of pancreatitis (inflammation of the pancreas).
The Vitalab a-Amylase Reagent is a single-part reagent for use with the Vitalab Selectra Analyzer. This reagent determines amylase through the cleavage of 2-chloro-4-nitrophenyl-a-D-maltotrioside (CNP-a-G3) to produce 2-chloro-4-nitrophenol.
This document describes the acceptance criteria and the study that demonstrates the Vitalab α-Amylase Reagent meets those criteria.
1. Table of Acceptance Criteria and Reported Device Performance
No explicit acceptance criteria values are provided in the document for each performance parameter. However, the study's reported performance serves as the basis for demonstrating its suitability and equivalence to the predicate device.
| Performance Characteristic | Acceptance Criteria (Implied by Predicate Equivalence) | Reported Device Performance (Vitalab α-Amylase Reagent) |
|---|---|---|
| Usable Range (Linearity) | Linearity over a specified range with high correlation to dilution factors. | Default sample volume: Linear range of 5 to 1,600 U/L. Recoveries = 0 U/L + 131 x (Dilution Factor), r = 0.9999, syx = 7.2 U/L. |
| Rerun sample volume: Linear range of 1,200 to 3,200 U/L. Recoveries = 0 U/L + 133 x (Dilution Factor), r = 0.9999, syx = 17 U/L. | ||
| Detection Limit | A detection limit demonstrating the ability to accurately measure low concentrations. | 0.4 U/L (mean + 2SD of repetitive assay of normal saline; 30 replicates, mean 0.3 U/L, SD 1.8 U/L). |
| Precision (Within-run and Total) | Acceptable levels of imprecision (low %CV) for various serum concentrations. | Default Mode: |
| Serum 1 (98 U/L): 1SD = 1.0, %CV = 1.0% (within-run); 1SD = 1.5, %CV = 1.5% (total) | ||
| Serum 2 (565 U/L): 1SD = 3.6, %CV = 0.6% (within-run); 1SD = 5.0, %CV = 0.9% (total) | ||
| Serum 3 (1,034 U/L): 1SD = 7.0, %CV = 0.7% (within-run); 1SD = 9.7, %CV = 0.9% (total) | ||
| Rerun Mode: | ||
| Serum 1 (1,961 U/L): 1SD = 17, %CV = 0.9% (within-run); 1SD = 25, %CV = 1.3% (total) | ||
| Serum 2 (2,517 U/L): 1SD = 26, %CV = 1.0% (within-run); 1SD = 41, %CV = 1.6% (total) | ||
| Serum 3 (3,002 U/L): 1SD = 40, %CV = 1.3% (within-run); 1SD = 50, %CV = 1.7% (total) | ||
| Correlation with Predicate Device | Strong correlation with a legally marketed predicate device, indicated by a regression equation close to y=x and a low sy.x. | Selectra = -6 U/L + 1.086 x Competitive Reagent, sy.x = 4.0 U/L. |
| Stability (Onboard Reagent) | Reagent stability for a specified period with minimal change in performance. | 14-day onboard stability, with total imprecision estimates less than 2 U/L or 1.2% for all controls. |
2. Sample Size Used for the Test Set and Data Provenance
- Linearity (Usable Range):
- Default sample volume: n = 28 (number of recovery solutions/dilution factors)
- Rerun sample volume: n = 60 (number of recovery solutions/dilution factors)
- Detection Limit: 30 replicates of normal saline.
- Precision: 60 replicates for each of the 6 serum samples tested (3 in default mode, 3 in rerun mode).
- Correlation: n = 120 mixed serum and plasma specimens. The document states these were "collected from adult patients", but the country of origin is not specified. The study appears to be retrospective, as specimens were "assayed" and then compared.
- Stability: Not explicitly stated, but involved the assay of "serum controls" over the 14-day period.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not applicable. This is an in vitro diagnostic device for measuring α-amylase levels, not an imaging or diagnostic algorithm requiring expert interpretation for ground truth. The "ground truth" for the performance studies is based on established analytical methods and reference ranges for the analyte.
4. Adjudication Method for the Test Set
Not applicable, as this is a quantitative chemical assay, not an interpretive diagnostic device.
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 reagent, not an AI-assisted diagnostic tool requiring human interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the studies described are standalone performance evaluations of the Vitalab α-Amylase Reagent operating on the Vitalab Selectra Analyzer. The device directly produces quantitative results for α-amylase.
7. The Type of Ground Truth Used
- Linearity: Based on theoretical dilution factors and measured recovery values, with the assumption that serial dilutions accurately represent the true concentration.
- Detection Limit: Statistical calculation from repeated measurements of a blank (normal saline).
- Precision: Defined by the variability of repeated measurements of control sera with known concentrations.
- Correlation: The "ground truth" for correlation was the measurement obtained from a "commercially available method" (predicate device: Roche α-Amylase EPS ver.2 Reagent). This is a comparative study against an established predicate, rather than an absolute ground truth from pathology or outcomes.
- Stability: Measured against the initial performance of the reagent and accepted analytical variation limits.
8. The Sample Size for the Training Set
Not applicable. This is not a machine learning or AI-based device, so there is no "training set" in the conventional sense. The development of the reagent and its optimization would have involved internal R&D, but not a formally defined "training set" for an algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as explained in point 8.
§ 862.1070 Amylase test system.
(a)
Identification. An amylase test system is a device intended to measure the activity of the enzyme amylase in serum and urine. Amylase measurements are used primarily for the diagnosis and treatment of pancreatitis (inflammation of the pancreas).(b)
Classification. Class II.