(30 days)
The CareSide™ BUN cartridge is intended for in vitro diagnostic use in conjunction will the Exigent Diagnostics CareSidc™ Analyzer to quantitatively measure urea nitrogen from whole blood, plasma or serum by laboratory professionals. When used in conjunction with the Exigent Diagnostics CareSideTM Creatinine test cartridge on the Exigent Diagnostics CareSide™ Analyzer, the BUN product may be used to calculate a BUN to creatinine ratio. The CareSide™ BUN test aids in the diagnosis and treatment of various renal and metabolic diseases.
This product is indicated for use with patients with various renal and metabolic diseases.
CareSide™ BUN cartridges are used with the Exigent Diagnostics CareSide™ Analyzer to measure BUN concentration in whole blood, plasma or scrum specimens. The CareSide™ BUN cartidge, a single use disposable in viro diagnostic test cartridge, aids in specimen separation and delivers a measured volume of plasma or serum to a dry film to initiate the measurement of BUN concentration. The film cartridge (patcht pending) contains all reagents necessary to measure Concentration. "The min and in conjunction with the CareSide™ Creatinine cartridge on the CareSide™ Analyzer, the analyzer calculates a BUN to creatinine ratio.
Each Exigent Diagnostics CareSide™ BUN cartridge consists of a BUN-specific multi-Jayer reagent film mounted in a plastic base with a hinged lid. The user introduces the whole blood, serum, or plasma specimen into the cartridge sample deposition well, closes the lid and inserts the cartridge into the Exigent Diagnostics CareSide™ Analyzer.
Once loaded, the CareSide™ analyzer scans the carridge barcode, brings the cartidge and the contained speciment to 37℃, and spins the cartidge to move the sample from the sample deposition well into the cartridge channels and chambers. As the cartridge continues to spin, the blood culls are separated from the plasmalscrum and the cells accumulate in the separation well. Ten microliters of plasma (or serum, as applicable) remain in the metering passage. Any excess sample flows into an overflow well,
The ten microliters of plasma (or serum, as applicable) is automatically dispensed onto the multi-layer reagent film. The spreading layer distributes the sample evenly on the film and filters large molecular weight components such as protein and dye fragments hefore the specimen enters the reaction layer. Urea then reacts with water in a urcasccatalyzed reaction to produce carbon dioxide and ammonia gas in the alkaline unvironment. The arnmonia gas permeates the porous gas permeation layer to reach the detection layer where it then reacts non-cazymatically with the yellow dye, hromocresol green, to form a green dye.
Test Reaction Sequence:
Urea + H2O - "Pease > 2NH3 + CO2
Bromocresol green (yellow) + NH3-> Green dye
As the cartridges spin, photodiodes measure reflectance of light emitted by wavelengthspecific light cmitting diodes (LEDs) at a lixed time. The analyzer uses the reflectance measurements and the lot-specific standard curve to calculate BUN concontration.
Here's an analysis of the provided text regarding the acceptance criteria and study for the CareSide™ Urea Nitrogen (BUN) device:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implicitly defined by demonstrating substantial equivalence to the predicate device, Vitros BUN DT Slides. The "Comparative Performance Characteristics" section provides the data to support this.
| Acceptance Criterion (Implicit) | CareSide™ BUN Reported Performance | Predicate Device (Vitros BUN DT Slides) Reported Performance |
|---|---|---|
| Detection Limit | 5 mg/dL | 1 mg/dL |
| Reportable Range | 5 to 140 mg/dL | 1 to 100 mg/dL |
| Accuracy (compared to predicate) | Mean recovery 100% | Not provided |
| Precision (Total CV at approx. 26-27 mg/dL) | Total CV, 26 mg/dL, 3.3% | Total CV, 27 mg/dL, 3.3% |
| Method Comparison (correlation with predicate) | CareSide™ = 1.00 (Vitros BUN DT) - 3.0, r=0.99 | (N/A - used as reference) |
| Linearity | Mean deviation approx -6%, r>0.99 | Not provided |
| Interference (Ascorbic Acid, Bilirubin, Hemoglobin, Triglycerides) | No significant interference observed at tested concentration | Not provided |
| Specimen Types & Anticoagulants Compatibility | No clinically significant difference between heparinized whole blood, serum, heparin plasma, and EDTA plasma. | No clinically significant difference between serum and heparin plasma. Whole blood is unsuitable. |
| Expected Values (Central 95% interval) | 6 to 16 mg/dL (combined male and female) | 9 to 20 mg/dL (male), 7 to 17 mg/dL (female) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not explicitly state the specific sample sizes used for each performance characteristic study (e.g., accuracy, precision, linearity, interference, method comparison). It only presents the results.
- Data Provenance: The document does not specify the country of origin of the data nor if the studies were retrospective or prospective. Given the context of a 510(k) submission to the FDA, it is highly likely the studies were conducted in a manner consistent with U.S. regulatory expectations, implying prospective clinical (or laboratory equivalent) evaluations.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. For a diagnostic device measuring a quantitative analyte like BUN, ground truth is typically established by reference laboratory methods, not by expert consensus in the way a qualitative diagnostic (e.g., image interpretation) might be.
4. Adjudication Method for the Test Set
This information is not applicable and therefore not provided. Adjudication methods like "2+1" or "3+1" are relevant for qualitative assessments, particularly in imaging or pathology where multiple experts may disagree. For a quantitative chemical measurement, discrepancies are typically resolved through re-testing or using a more definitive reference method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A MRMC comparative effectiveness study was not performed and is not applicable for this device. This type of study is specifically for evaluating the effectiveness of a device (often AI-assisted) on human reader performance, common in medical imaging. The CareSide™ BUN device is a standalone in vitro diagnostic system for chemical measurement.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop Performance)
Yes, a standalone performance study was done. The entire "Comparative Performance Characteristics" section describes the performance of the CareSide™ BUN device as a standalone algorithm/system, comparing its quantitative output to the predicate device and established analytical expectations. The device takes a sample and produces a BUN concentration without direct human interpretation of the result (beyond reading the reported number).
7. Type of Ground Truth Used
The ground truth used for these studies appears to be:
- Reference Method/Predicate Device: For method comparison, the "Vitros BUN DT" predicate device and/or an "Urease conversion to ammonia. Glutamic dehydrogenase linked NADH oxidation of ammonia" reference method serves as the ground truth.
- Known Concentrations: For studies like linearity, accuracy (mean recovery), and interference, control samples with known, established BUN concentrations would have been used.
8. Sample Size for the Training Set
The document does not provide information regarding a training set sample size. This is typical for in vitro diagnostic (IVD) devices that are not "AI-driven" in the contemporary sense. The device relies on a pre-programmed algorithm based on chemical reactions and optical detection, calibrated using lot-specific standard curves, rather than a machine learning model that requires a distinct training phase with a large dataset.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a "training set" in the context of machine learning, this information is not provided and is not applicable. The device's operational parameters are based on scientific principles of the chemical reaction and optical properties, and calibration is performed with standard laboratory calibrators (referred to as "lot-specific standard curve" in the device description).
§ 862.1770 Urea nitrogen test system.
(a)
Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of certain renal and metabolic diseases.(b)
Classification. Class II.