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The Lin-Zhi International, Inc. (LZI) Methamphetamine Enzyme Immunoassay for Pictus Analyzers is intended for the qualitative determination of d-methamphetamine in human urine at a cutoff value of 500 ng/mL. The system was calibrated with d-methamphetamine. The assay provides a rapid screening procedure for determining the presence of d-methamphetamine in urine.

The assay provides only a preliminary analytical result. A more specific alternative analytical chemistry method must be used in order to obtain a confirmed analytical result. Gas or Liquid Chromatography/Mass Spectrometry (GC/MS or LC/MS) are the preferred confirmatory methods. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary test result is positive.

Lin-Zhi International, Inc. (LZI) Methamphetamine Enzyme Immunoassay for Pictus Analyzers is intended for the qualitative determination of methamphetamine in human urine, at a cutoff value of 500 ng/mL.

The assay is designed for laboratory use by trained professionals with various automated clinical chemistry analyzers.

This assay provides a rapid screening procedure for assessing the presence of d-methamphetamine in urine. The assay provides only a preliminary analytical result reported as a positive or negative. A more specific alternative chemical must be used in order to obtain a confirmed analytical result. Gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary test result is positive. The analyzer photometer reads the absorbance at 340mm at time intervals dictated by the Methamphetamine application stored in the analyzer memory, and the change in absorbance is calculated automatically.

Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided text.

Note: This document describes a traditional in-vitro diagnostic (IVD) device (immunoassay for drug detection) and not an AI/ML-driven medical device, hence many of the requested points related to AI/ML device validation (e.g., number of experts for ground truth, MRMC study, training set details) are not applicable. I will indicate "N/A" for these points.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the study success definitions and the comparison to the predicate device.

• 0-375 ng/mL: 100% Negative
• 500 ng/mL: 49% Negative (41 samples), 51% Positive (43 samples)
• 625-1000 ng/mL: 100% Positive
  Within Run Precision (19-20 samples per level):
• 0-375 ng/mL: 100% Negative
• 500 ng/mL: 60% Negative (12 samples), 40% Positive (8 samples)
• 625-1000 ng/mL: 100% Positive (one sample at 625 showed 19 samples, all positive) |
  | Cross Reactivity: Demonstrate similar cross-reactivity profiles to the predicate device for structurally related compounds. | Pictus P700 vs. Hitachi 717 (Predicate):
• d-Methamphetamine (500 ng/mL): Positive (P700) / 211 (Hitachi)
• d-Amphetamine (50,000 ng/mL): Positive (P700) / 212.1 (Hitachi)
• Methylenedioxyamphetamine (MDA) (72,500 ng/mL): Positive (P700) / 210.1 (Hitachi)
• Methylenedioxymethylamphetamine (MDMA) (1,500 ng/mL): Positive (P700) / 207.8 (Hitachi)
  The results demonstrated "cross-reactivity of the reagents with the Pictus 700 was the same as that demonstrated with the same reagents on the Hitachi 717." |
  | Accuracy - Method Comparison: | Pictus 700 Methamphetamine Tests vs LC/MS Reference (98 samples):
• 0-350 ng/mL (negative samples by LC/MS):
  • LC/MS 30% of CO (Positive): 5 positive
  • LC/MS >50% of COV (Positive): 7 positive
  • LC/MS Very High Positive: 21 positive
  • All samples in this range (5 + 7 + 21 = 33) were reported as positive by Pictus 700 (100.0% agreement for positive samples).
• Between 351 and 649 ng/mL (around cutoff): At least 95% congruent in terms of negative and positive results on either side of the 500 ng/mL cutoff.
  • LC/MS Near CO Negative (351-499 ng/mL): 4 negative, 1 positive (discordant sample 61634620, LC/MS 488, Candidate 514 positive)
  • LC/MS Near CO Positive (501-650 ng/mL): 15 positive, 0 negative
  • The overall accuracy was 98.0% for negative agreement and 100.0% for positive agreement against GC/MS. |
    | On-board Reagent Stability: Reagent must be stable on the analyzer for at least 14 days, with a calibration frequency of 7 days. | The LZI Methamphetamine reagent was found to be "stable on-board the Pictus 700 analyzer for at least 14 days, and calibration frequency is defined at 7 days." The study maintained accuracy over the 14-day period. |

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

• Precision:
  • Total Precision: 84 samples per MAMP level (9 levels tested). Total samples = 84 * 9 = 756 individual sample runs across different levels.
  • Within Run Precision: 19-20 samples per MAMP level (9 levels tested). Total samples = approximately 180 individual sample runs.
• Cross Reactivity: 4 structurally related compounds tested in duplicate.
• Accuracy - Method Comparison: 98 human urine samples.
• On-board Reagent Stability: 3 fresh sample pools, analyzed on Day 1, 3, 6, 7, 10, 13, 14, and 17 in duplicate or triplicate.
• Data Provenance: Not explicitly stated (e.g., country of origin). The studies appear to be prospective as they involved systematically preparing samples at specific concentrations and testing them, or collecting fresh samples for analysis. This is typical for IVD assay validation studies.

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

N/A. For IVD devices like this, ground truth is established by analytical methods, not human expert consensus. The "ground truth" for the accuracy study was established by Gas or Liquid Chromatography-Mass Spectrometry (GC/MS or LC/MS), which are laboratory-based confirmatory methods.

4. Adjudication method for the test set

N/A. Ground truth was established by LC/MS, an objective analytical method, so no human adjudication was required.

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

N/A. This is not an AI-driven device. It is an automated laboratory assay.

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

Yes, in a sense. The device (Pictus 700 with LZI MAMP reagent) performs the analysis automatically in a "standalone" fashion. The results are then interpreted as positive or negative based on the 500 ng/mL cutoff, which is essentially an "algorithm." There is no human interaction for result generation once samples are loaded. The study directly evaluates this standalone performance against the LC/MS reference method.

7. The type of ground truth used

The ground truth used was analytical measurement by Gas or Liquid Chromatography-Mass Spectrometry (GC/MS or LC/MS). For the purpose of drug testing, these are considered the gold standard confirmatory methods.

8. The sample size for the training set

N/A. This document pertains to an IVD reagent and instrument system, not an AI/ML model that requires a "training set" in the machine learning sense. The device is based on enzyme immunoassay chemistry.

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

N/A. See point 8. The "training" for such a system involves calibrating the instrument with known calibrators, not training an algorithm on a large dataset.

Ask a specific question about this device

Autoanalyzer Pictus 400 is designed for Clinical Laboratory Use, with direct determination of Na, K, Cl in serum, and Glucose in serum, and to measure a variety of analytes that may be adaptable to the analyzer depending on the reagent used.

Sodium measurements are used for monitoring electrolyte imbalances. Potassium measurements are used for diagnosis in diseases with high and low Potassium levels. Chloride measurements are primarily use to detect and treatment of metabolic disorders. Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, and idiopathic hypoglycemia, and of pancreatic islet cell carcinoma.

Not Found

This document is a 510(k) premarket notification from the FDA, indicating clearance for the Diatron PICTUS 400 device. While it lists the "Indications for Use" for various analytes (Na, K, Cl, Glucose), it does not contain any information about acceptance criteria, device performance studies, sample sizes, ground truth establishment, expert qualifications, or MRMC studies.

Therefore, I cannot fulfill your request for that specific information based on the provided text. The document's purpose is to state FDA's determination of substantial equivalence, not to detail the technical validation studies.

Ask a specific question about this device