(13 days)
The Carbon Dioxide assay is used for the quantitation of carbon dioxide in human serum or plasma. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance.
Carbon Dioxide (CO2) is an in vitro diagnostic assay for the quantitative determination of carbon dioxide in human serum or plasma. The Carbon Dioxide assay is a clinical chemistry assay in which carbon dioxide, as bicarbonate (HCO2 - ), and phospho(enol)pyruvate (PEP) are converted to oxalacetate and phosphate in the reaction, catalyzed by phospho(enol)pyruvate carboxylase (PEPC). Malate dehydrogenase (MDH) catalyzes the reduction of oxalacetate to malate with the concomitant oxidation of reduced nicotinamide adenine dinucleotide (NADH). The resulting decrease in absorbance at 380 nm is proportional to the CO2 content of the sample.
The document describes the Abbott Laboratories Carbon Dioxide (CO2) assay and its substantial equivalence to the Boehringer Mannheim Carbon Dioxide assay on the Hitachi 717 Analyzer.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state "acceptance criteria" as a separate, pre-defined set of thresholds. Instead, it demonstrates substantial equivalence by showing that the performance characteristics of the new device are "similar" to or "acceptable" in comparison to the predicate device. For the purpose of this analysis, the performance of the predicate device (Boehringer Mannheim Carbon Dioxide assay) serves as the implicit acceptance criteria, and the reported device performance is that of the Abbott Carbon Dioxide assay.
| Performance Metric | Implicit Acceptance Criteria (Predicate Device K933461) | Reported Device Performance (Abbott CO2 Assay) |
|---|---|---|
| Method Comparison (Correlation) | Acceptable correlation to predicate | Correlation coefficient = 0.9906 |
| Method Comparison (Slope) | Similar to predicate | Slope = 0.909 |
| Method Comparison (Y-intercept) | Similar to predicate | Y-intercept = 0.088 mEq/L |
| Precision (Within-run, Between-run, Between-day) | Acceptable precision for clinical use | Total %CV for Level 1 = 10.2%, Total %CV for Level 2 = 9.6% |
| Linearity | Linear up to a clinically relevant range | Linear up to 44.8 mEq/L |
| Limit of Quantitation (Sensitivity) | Clinically relevant sensitivity | 2.80 mEq/L |
2. Sample Size Used for the Test Set and Data Provenance:
The document briefly mentions "Comparative performance studies were conducted" and "Precision studies were conducted using the Carbon Dioxide assay," but it does not specify the sample size used for these test sets.
The data provenance is not explicitly stated (e.g., country of origin, retrospective or prospective). However, the nature of a clinical chemistry assay comparison generally implies prospective data collection in a laboratory setting using human serum or plasma samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
This information is not provided in the document. For an in vitro diagnostic (IVD) device like this, the "ground truth" is typically the measurement obtained from the predicate device or a reference method. It's not usually established by human expert consensus in the same way it might be for an image-based diagnostic.
4. Adjudication Method for the Test Set:
This information is not applicable/not provided. Adjudication methods like 2+1 or 3+1 are typically used in image interpretation studies where human experts disagree. For a quantitative chemical assay, the "ground truth" (or reference measurement) is established by the method itself.
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:
This is not applicable as the device is a clinical chemistry assay (an in vitro diagnostic), not an AI-powered diagnostic that assists human readers. Therefore, an MRMC study and
the concept of human reader improvement with AI are not relevant to this submission.
6. If a Standalone (i.e., algorithm-only without human-in-the-loop performance) was done:
Yes, the studies conducted were standalone performance evaluations of the Abbott Carbon Dioxide assay.
The performance characteristics (correlation, precision, linearity, sensitivity) were determined for the assay system itself, without human intervention in the measurement process (beyond sample handling).
7. The Type of Ground Truth Used:
The ground truth used for comparison was the measurements obtained from the predicate device, the Boehringer Mannheim Carbon Dioxide assay on the Hitachi 717 Analyzer (K933461). This falls under the category of a well-established reference method or predicate device performance.
8. The Sample Size for the Training Set:
This information is not applicable/not provided. This device is a traditional chemical assay, not an AI/machine learning algorithm, so there is no "training set" in the context of machine learning. The assay's parameters would have been optimized during its development, but this is a different concept than a machine learning training set.
9. How the Ground Truth for the Training Set Was Established:
This information is not applicable as there is no training set for this type of device.
§ 862.1160 Bicarbonate/carbon dioxide test system.
(a)
Identification. A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole blood. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance.(b)
Classification. Class II.