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The A/C Enzymatic Vitamin B6 Assay is intended for the quantitative in vitro diagnostic determination of pyridoxal 5'-phosphate (PLP, vitamin Bo) in EDTAhuman plasma. The device will be used to monitor PLP concentrations in plasma for aid in diagnosis of vitamin B6 deficiency. The A/C Enzymatic Vitamin B6 Assay is for IN VITRO DIAGNOSTIC USE ONLY.

The A/C Enzymatic Vitamin B6 Assay is calibrated with external standardization and matrix-matched calibration solutions. Two sources of quality control material (A low and high level of PLP) are assaved in each run together with A/C Calibrators and samples for the verification of the accuracy and precision of the A/C Enzymatic Vitamin B6 Assay.

The A/C Enzymatic Vitamin B6 Assay uses the apo form of recombinant PLPdependent enzyme, homocysteine-a.y-lyase (rHCYase). The restoration of enzymatic activity by reconstitution of the holo-enzyme is linearly dependent on the amount of PLP bound to apo-enzyme. Nanomolar concentrations of PLP can then be measured by the conversion of millimolar concentrations of homocysteine to hydrogen sulfide, which is determined using DBPDA, the combination of which forms a chromophore, the absorbance is read with 96-well plate absorbance reader.

The A/C Enzymatic Vitamin B6 Assay is a three-step reaction with four reagents. which runs at 37°C or room temperature. The total assay takes 90 minutes. The assay can be performance on 96-well absorbance reader with 660-690m filter.

Here's a breakdown of the acceptance criteria and the study details for the A/C Enzymatic Vitamin B6 Assay, based on the provided 510(k) summary:

1. Acceptance Criteria and Reported Device Performance

The acceptance criteria are implicitly derived from the comparison to the predicate device. The study aims to demonstrate substantial equivalence, meaning the new device performs similarly to the already legally marketed predicate (ALPCO Vitamin B6 REA method). The performance is assessed through correlation and regression analysis, and bias.

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

• Sample Size: Fifty-four (54) EDTA-plasma samples.
• Data Provenance: Not explicitly stated regarding country of origin. The study appears to be retrospective, using existing EDTA-plasma samples. No information suggests prospective data collection.

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

This information is not applicable and not provided in the summary. For this type of in vitro diagnostic device (IVD) assay, the "ground truth" for the test set is established by the results obtained from the predicate device itself, as the goal is to demonstrate equivalence, not diagnostic accuracy against a clinical gold standard (like pathology).

4. Adjudication Method for the Test Set

Not applicable. There was no expert adjudication involved in comparing the results between the new device and the predicate device. The comparison was a direct statistical analysis of the numerical results generated by both assays.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is typically performed for diagnostic imaging devices or other assessments where human interpretation is a key component, comparing human performance with and without AI assistance. This 510(k) pertains to a laboratory assay (an IVD) where the device provides a direct quantitative result, not an interpretation requiring human readers.

6. Standalone (Algorithm-Only) Performance Study

Yes, implicit in the study. The comparison of the A/C Enzymatic Vitamin B6 Assay to the ALPCO Vitamin B6 REA assay is inherently a standalone performance study. The algorithm (assay) generates a quantitative value, which is then directly compared to the values generated by the predicate assay. There is no "human-in-the-loop" component for the measurement itself.

7. Type of Ground Truth Used

The "ground truth" for this comparative study was the results obtained from the predicate device (ALPCO Vitamin B6 REA assay). The new device's performance was evaluated by its agreement with these predicate device results. This is a common approach for IVD devices demonstrating substantial equivalence.

8. Sample Size for the Training Set

The 510(k) summary does not explicitly mention a "training set" in the context of machine learning, as this is a biochemical assay, not an AI/ML algorithm that requires training data in the typical sense. The assay is developed based on biochemical principles and optimized through research and development, but there's no data provided about a distinct "training set" for an algorithm.

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

As noted above, the concept of a "training set" for establishing "ground truth" is not directly applicable in the summary provided for this type of enzymatic assay. The assay's analytical characteristics and performance are based on its underlying biochemical mechanism and empirical validation, rather than learning from a labeled training dataset.

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The A/C Portable Enzymatic Homocysteine Assay on the A/C Diagnostics Reader (HyTek-205) is intended for the quantitative determination of total homocysteine (tHCY) in human plasma or serum. The device can assist in the diagnosis and treatment of patients suspected of having hyperhomocysteinemia. The A/C Enzymatic Homocysteine Assay is for in vitro diagnostic use.

The A/C Portable Enzymatic Homocysteine Assay is calibrated with A/C Enzymatic Homocysteine Assay Calibrators. A/C Enzymatic Homocysteine Assay Controls are assayed for the verification of the accuracy and precision of the A/C Portable Enzymatic Homocysteine Assay.

The A/C Enzymatic Homocysteine Assay measures tHCY. The principle of the assay is that after reduction, tHCY is depleted by Homocysteinase (rHCYase) and produces hydrogen sulfide (H2S), which is determined using N.N-dibutyl phenylene diamine (DBPDA), the combination of which forms a chromophore, the fluorescence is measured by the A/C Diagnostics Reader (HyTek-205).

The A/C Portable Enzymatic Homocysteine Assay is a three-steps reaction, which runs at room temperature. The total assay takes 80 minutes, and the A/C Diagnostics Reader is the only equipment needed.

Here's an analysis of the provided text regarding the A/C Portable Enzymatic Homocysteine Assay, focusing on acceptance criteria and the supporting study:

The provided document is a 510(k) summary for a medical device seeking substantial equivalence to a predicate device. It focuses on demonstrating that the new device performs as well as, or better than, the predicate. Therefore, the "acceptance criteria" are implicitly established by the performance of the predicate device. The study aims to show that the new device's performance aligns closely with that of the predicate.

Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated as numerical thresholds in this summary. Instead, they are implied by the reported performance of the predicate device, which the new device aims to match or closely approximate. The primary performance metric for comparison is the correlation and mean difference between the new device and the predicate.

Study Details

1. Sample Size used for the test set and the data provenance:

   • Sample Size: 50 plasma samples.
   • Data Provenance: Not explicitly stated regarding country of origin or specific demographics. The samples are referred to as "fifty plasma samples," implying they were clinical samples. The study is retrospective, as it compares the new device's results on these samples against those obtained from an existing, already cleared predicate device (the A/C Automatic Enzymatic HCY Assay on Hitachi 912).

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

   • This is not applicable to this type of device and study. The "ground truth" for a quantitative assay like this is typically established by comparison to a reference method or a substantially equivalent predicate device, not by expert consensus on qualitative interpretation. The predicate device itself (A/C Automatic Enzymatic HCY Assay on Hitachi 912) served as the reference for comparison.

3. Adjudication method for the test set:

   • Not applicable. This is a quantitative assay comparison, not a diagnostic imaging or expert interpretation study requiring adjudication.

4. 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:

   • No MRMC study was done. This is a comparison of two in vitro diagnostic devices, not an AI-assisted diagnostic tool involving human readers.

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

   • This is partially applicable, as the "A/C Portable Enzymatic Homocysteine Assay on the A/C Diagnostics Reader" is a standalone system in the sense that it performs the measurement without human subjective interpretation of results, beyond the operator running the test. The study is comparing the performance of this standalone system against another standalone system (the predicate device). The performance metrics (correlation, regression, mean difference, precision) are all "algorithm only" or "device only" metrics.

6. The type of ground truth used:

   • The "ground truth" for this study was the results obtained from the predicate device, the A/C Automatic Enzymatic HCY Assay on Hitachi 912 (K030754). This is a common approach for demonstrating substantial equivalence for in vitro diagnostic devices.

7. The sample size for the training set:

   • The document does not explicitly mention a "training set" in the context of device development or machine learning. For in vitro diagnostic assays, performance characteristics are typically established through analytical studies (e.g., precision, linearity, interference) and clinical comparison studies (like this one) using patient samples, rather than a machine learning training paradigm.

8. How the ground truth for the training set was established:

   • Not applicable, as a "training set" in the machine learning sense is not described. The predicate device's performance was already established through its prior 510(k) clearance (K030754).

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• The A/C Enzymatic Homocysteine Assay is intended for the quantitative determination of total homocysteine (tHCY) in human plasma or serum.
• The device can assist in the diagnosis and treatment of patients suspected of having hyperhomocysteinemia.
• The A/C Enzymatic Homocysteine Assay Kit is only for in vitro diagnostic use.

The A/C Enzymatic Homocysteine Assay is calibrated with A/C Enzymatic Homocysteine Assay Calibrators. The A/C Enzymatic Homocysteine Assay is assayed for the verification of the accuracy and precision on the Hitachi 912 Automatic Analyzer.

The A/C Enzymatic Homocysteine Assay measures tHCY. The principle of the assay is that recombinant homocysteinase (rHCYase) produces hydrogen sulfide (H2S) from tHCY, which is quantified by use of N,N-dibutyl phenylene diamine (DBPDA), the combination of which forms a chromophore.

The A/C Enzymatic Homocysteine Assay on the Hitachi 912 Automatic Analyzer used four reagents, a number compatible with implementation on the Hitachi 912 Automatic Analyzer. We used 30 uL of EDTA plasma in a dithiothreitol (DTT) reduction reaction (1 mmol/L DTT, 0.2% Triton X-100 in 40 mmol/L sodium phosphate buffer [pH 8.3]) for 1.5 minutes to release bound homocysteine. The rHCYase reaction (0.05 mg/ml in 40 mmol/L sodium phosphate buffer [pH 8.3] with 20 umol/L pyridoxal 5-phosphate [PLP]) is then run for 3.5 minutes. The DBPDA chromophore (12.5 mmol/L DBPDA in 1.5 N H2SO4) is then added and 5 minutes later, an oxidant, potassium ferricyanide (5 mmol/L K3Fe(CN), in 10 mmol/L sodium phosphate buffer [pH 7.6]), is added. Five minutes after addition of oxidant, the end-points are read at absorbances of 700 and 660 nm. As the assay is based on an increase in absorbance over baseline, no blank without enzyme was used. The detection limit of the assay is 1.5 umol/L defined by quantification of a serial dilution of a plasma sample of tHCY diluted to 0.77 umol/L. The limit of quantification is defined as the lowest concentration measured having a CV

Here's an analysis of the provided text regarding the A/C Enzymatic Homocysteine Assay, focusing on acceptance criteria and the supporting study:

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state formal "acceptance criteria" in a clear, quantified manner for regulatory approval. Instead, it describes performance characteristics and compares them to a predicate device. The performance is deemed acceptable because it is within ranges reported for currently-used assays including the predicate.

Here's a table summarizing the performance characteristics presented, with an interpretation of implied acceptance based on the comparison to existing assays:

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