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The VerifyNow PRUTest is a whole blood test used in the laboratory or point of care setting to measure the level of platelet P2Y12 receptor blockade. For in vitro diagnostic use. For professional use only.

Device Description

The VerifyNow System is a turbidimetric-based optical detection system that measures plateletinduced aggregation. The system consists of an instrument, a disposable test device and quality control materials. Quality control measures include an instrument based electronic quality control (EOC). two levels of wet quality controls (WOC), internal quality controls, and shipping controls. The instrument controls all assay sequencing, temperature, reagent-sample mixing and performs self-diagnostics. The degree of platelet function is determined and the result is displayed.

The VerifyNow PRUTest device contains three lyophilized reagent pellets in separate reaction chambers within the test device: 1) ADP pellet consisting of a preparation of Fibrinogen and BSA coated beads, adenosine-5-diphosphate (ADP), prostaglandin E1 (PGE1), dye, buffer, and a preservative; 2) TRAP pellet (Internal Control) consisting of a preparation of iso-TRAP (Thrombin Receptor Activating Peptide), Fibrinogen and BSA coated beads, buffer, dye, and a preservative; and 3) No-Agonist Pellet (NAP) consisting of a preparation of BSA coated beads, dye, buffer, and a preservative.

AI/ML Overview

The provided text describes the performance studies for the VerifyNow PRUTest device, demonstrating its substantial equivalence to a predicate device (VerifyNow P2Y12 Assay).

Here's an analysis of the acceptance criteria and the studies that prove the device meets these criteria:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly list a single table of "acceptance criteria" for all tests, but rather describes the criteria within the context of each study. Below is a compilation of the criteria and performance for the key studies described:

Study/Parameter	Acceptance Criteria	Reported Device Performance
Method Comparison	Slope not statistically significantly different from 1.0; Intercept not statistically significantly different from 0; Correlation (r) greater than 0.9.	P2Y12 Rep 1 vs. PRUTest Rep 1: Slope = 1.01 (95% CI: 0.97–1.05), p-value = 0.56; Intercept = -0.77 (-8.00-6.50); Correlation R = 0.98. P2Y12 Avg. vs. PRUTest Avg.: Slope = 1.04 (95% CI: 1.00-1.07), p-value = 0.07; Intercept = -4.57 (-11.2-2.05); Correlation R = 0.98. Performance met criteria.
Precision (WQC Level 1)	PRU result ≤ 30 (indicates negative control/no aggregation).	All WQC Level 1 results fell within the acceptable range of ≤ 30 PRU. At the nine-month time point, the range of PRU values generated with WOC Level 1 did not exceed 30 PRU.
Precision (WQC Level 2)	Within-run, Between-run, Between-day, Between-lot, and Total %CVs for WQC Level 2 (specific values are not given as general acceptance criteria, but implied by the successful analysis against CLSI EP05-A2). For stability, Percent recovery ≥ 90 to ≤ 110% of baseline PRU.	Between-lot: Total SD = 22.2, Total %CV = 7.4. Between instrument: Total SD = 24.2, Total %CV = 8.0. For stability, percent recovery of WQC Level 2 passed acceptance criterion (≥ 90 to ≤ 110%) at nine months.
Precision (Whole Blood - Multiple Lot)	Individual CVs for Within-run, Between-run, Between-day, Between-lot components each < 10% (for most categories, N/A for Between-day for specific donors).	Most individual donor results showed component %CVs < 10%, though some Between-day values were higher (e.g., Donor 1 Between-day %CV 15.0). All specific donor data are provided in Table H. However, the overall conclusion is not explicitly stated if all individual criteria were met for every donor.
Precision (Whole Blood - Multiple Instrument)	Individual CVs for Within-run, Between-run, Between-day, Between-lot components each < 10% (for most categories, N/A for Between-day for specific donors).	Similar to multiple lot, most individual donor results showed component %CVs < 10%, with some exceptions (e.g., Donor 7 Between-run %CV 17.7 and Between-day %CV 57.1). All specific donor data are provided in Table I.
Open Pouch Device Stability (Whole Blood)	Percent recovery of VerifyNow PRUTest values ≤ 10% deviation from baseline.	Met acceptance criteria after exposure to 61-73% RH and 21-24°C temperatures for 10 hours.
Open Pouch Device Stability (WQC Level 2)	PRU result remained within the allowable range (230–362).	Remained within the allowable range for 10 hours under the same conditions.
Sample Wait Time	Not explicitly stated, but the study determined an appropriate value.	Determined to be 10 minutes (minimum storage time after venipuncture).
Sample Stability	Not explicitly stated, but the study determined an appropriate value.	Determined to be four hours (blood sample must be assayed prior to four hours from draw time).
Interfering Substances	Percent recovery which deviated less than 10% from baseline PRUTest values.	Each interferent tested showed percent recovery deviating less than 10% from baseline PRUTest values. None of the substances significantly interfered.
Reagent Stability (WQC Level 1)	PRU result < 30.	At the nine-month time point, the range of PRU values generated did not exceed 30 PRU. All test intervals met criteria.
Reagent Stability (WQC Level 2)	Percent recovery ≥ 90 to ≤ 110% of the baseline PRU result.	At the nine-month time point, percent recovery passed criteria. All lots fell within ± 10% of the control condition.
Reagent Stability (Donor Whole Blood)	Percent recovery ≥ 90 to ≤ 110% of the baseline PRU result.	At the nine-month time point, percent recovery passed criteria. Aggregated lot data fell within ± 10% of the control condition.
Reagent Stability (Inhibited Whole Blood)	Percent recovery ≥ 90 to ≤ 110% of the baseline PRU result.	At the nine-month time point, percent recovery passed criteria. Aggregated lot data fell within ± 10% of the control condition.

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

Method Comparison: 119 samples. The origin is not specified, but the study involved "three investigational intended use sites." It is implied to be prospective, collected for the purpose of the study.
Reference Range Study: 152 evaluable healthy donors. Provenance not specified, but likely collected prospectively for the study.
Expected PRUTest values (Treatment-naïve ACS patients): 84 patients. Provenance not specified, likely collected prospectively for the study.
Expected PRUTest values (Clopidogrel-treated ACS patients): 71 patients. Provenance not specified, likely collected prospectively for the study.
Precision Studies (WQC Level 2): 240 tests (for both Between-lot and Between-instrument). Likely collected prospectively for the study.
Precision Studies (Whole Blood): 9 donors (each sampled multiple times, e.g., 30 to 120 reps per donor across days/runs/lots/instruments). Provenance not specified, likely collected prospectively for the study.
Open Pouch Device Stability: Whole blood samples (n=3) and WQC Level 2. Likely collected prospectively for the study.
Interfering Substances: Samples from 11 different donors. Likely collected prospectively for the study.
Reagent Stability (WQC Level 1, 2): Multiple lots (3 each of WQC levels and reagent devices), tested at time zero, 3, 6, and 9 months (number of individual tests not specified but for WQC Level 1 at 9 months, N=108). Likely collected prospectively for the study.
Reagent Stability (Donor Whole Blood): Whole blood samples from normal donors (specific N not specified, but tested across 3 reagent lots at 0, 3, 6, 9 months). Table N specifically shows data for 2 donors, at 9-month time point (N=3 for each lot/donor combination, total of 18 samples per donor for the specific comparison). Likely collected prospectively for the study.
Reagent Stability (Inhibited Whole Blood): 2 donors (Donors 399 and 1077). Similar breakdown as above, tested across 3 reagent lots at 9 months. Likely collected prospectively for the study.

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

The document describes in vitro diagnostic (IVD) device performance. For this type of device, ground truth is typically established by comparative measurements against a recognized reference method or by established laboratory-based assays (like the predicate device or clinical reference ranges) rather than expert consensus on image interpretation or clinical diagnosis. Therefore, "experts" in the context of establishing ground truth as typically understood for imaging AI models (e.g., radiologists) are not applicable here. The ground truth relies on the inherent biochemical mechanism of the device (platelet aggregation) and comparison to established methods.

4. Adjudication Method for the Test Set:

Not applicable in the conventional sense for image or clinical diagnosis adjudication. The "ground truth" for the analytical performance studies (method comparison, precision, stability, interference) is derived from quantitative measurements and statistical analysis, often against the predicate device or a control condition.

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 device is an automated platelet aggregation system, an IVD. It is not an AI-assisted diagnostic tool that aids human "readers" (like radiologists or pathologists) in interpreting complex data. The device itself performs the measurement and outputs a quantitative result (PRU value).

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

Yes, the studies describe the standalone performance of the VerifyNow PRUTest system. The system "automatically dispenses... blood... with no blood handling required by the user." The instrument "controls all assay sequencing, temperature, reagent-sample mixing and performs self-diagnostics. The degree of platelet function is determined and the result is displayed." This indicates it is an automated, standalone system.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc):

The ground truth used primarily consists of:

Comparative Analytical Performance: Measurements generated by the legally marketed predicate device (VerifyNow P2Y12 Assay) and comparison against it.
Established Reference Materials/Controls: Wet Quality Controls (WQC) with known characteristics.
Clinically Relevant Ranges: Reference ranges and expected values established statistically from healthy donors and patient populations (treatment-naïve, treated with clopidogrel).
Statistical Analysis: Adherence to CLSI guidelines (EP28-A3c, EP05-A2, EP07-A2) for establishing reference intervals, evaluating precision, and testing interference.

8. The Sample Size for the Training Set:

The document does not specify a "training set" in the context of an algorithm that learns from data in the way a machine learning model does. This device is described as a turbidimetric-based optical detection system, implying a fixed algorithm and chemical reagent system rather than a machine learning algorithm requiring a distinct training phase with a labeled dataset. Its development would involve optimization of reagents, optical detection parameters, and algorithms to convert optical signals to PRU values, which is a different paradigm than typical AI/ML training.

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

As there is no "training set" in the AI/ML context, this question is not directly applicable. The "ground truth" for the device's design and calibration would have been established during its development through a combination of:

Biochemical principles of platelet aggregation.
Empirical optimization of reagent concentrations and measurement parameters.
Comparison to gold standard methods or other validated platelet function assays during the research and development phase to ensure the system accurately reflects platelet P2Y12 receptor blockade.

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