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UniCel DxC SYNCHRON Systems Glucose reagent (GLUH), when used in conjunction with UniCel® DxC 600/800 SYNCHRON System(s) and SYNCHRON Systems AQUA CAL 1 and 3, is intended for the quantitative determination of glucose concentration in human serum. plasma, urine or cerebrospinal fluid (CSF).

Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, idiopathic hypoglycemia, and pancreatic islet cell carcinoma.

GLUH reagent is used to measure the glucose concentration by a timed endpoint method. In the reaction, hexokinase (HK) catalyses the transfer of a phosphate group from adenosine triphosphate (ATP) to glucose to form adenosine diphosphate (ADP) and glucose-6phosphate. The glucose-6-phosphate is then oxidized to 6-phosphogluconate with the concomitant reduction of ß-nicotinamide adenine dinucleotide (NAD) to reduced ßnicotinamide adenine dinucleotide (NADH) by the catalytic action of glucose-6-phosphate dehydrogenase (G6PDH).

The UniCel® DxC 600/800 SYNCHRON System(s) automatically proportions the appropriate sample and reagent volumes into the cuvette. The ratio used is one part sample to 100 parts reagent. The system monitors the change in absorbance at 340 nanometers. This change in absorbance is directly proportional to the concentration of glucose in the sample and is used by the System to calculate and express glucose concentration.

Here's a summary of the acceptance criteria and the study that proves the device meets them, based on the provided text:

Device: UniCel DxC SYNCHRON Systems Glucose (GLUH) reagent

1. Table of Acceptance Criteria and Reported Device Performance

Note: The document describes the "claimed" limits for some performance characteristics, implying these are the acceptance criteria. For others, the criteria are implied by the study design (e.g., linearity within a range, interference values less than or equal to a certain threshold).

• Serum: Slope 0.982, Intercept -1.02, R 1.000
• CSF: Slope 0.978, Intercept 1.25, R 1.000
• Urine: Slope 0.989, Intercept 2.08, R 1.000

UniCel DxC 800:

• Serum: Slope 0.999, Intercept -1.60, R 1.000
• CSF: Slope 1.002, Intercept -0.61, R 1.000
• Urine: Slope 0.973, Intercept 2.86, R 1.000
  (All reported R-values are 1.000, indicating excellent correlation) |
  | Anticoagulant Effects | Minimal impact on glucose measurements (Deming Regression slope ~1, intercept ~0, R ~1). | DxC600:
• Sodium Heparin: y= 0.983 + 0.849, R= 0.999
• Lithium Heparin: y= 0.994 + 0.393, R= 0.999
• Sodium Fluoride/Potassium Oxalate: y= 0.995 + 1.007, R= 0.999

DxC800:

• Sodium Heparin: y= 0.998 - 0.172, R= 0.999
• Lithium Heparin: y= 1.02 - 2.476, R= 1.000
• Sodium Fluoride/Potassium Oxalate: y= 1.012 - 0.302, R= 0.999
  (All R-values are 0.999 or 1.000, indicating strong correlation) |
  | Precision | Within run SD ≤ 2.0 mg/dL, Total SD ≤ 3.0 mg/dL. Within run %CV ≤ 2.0%, Total %CV ≤ 3.0% (at or above changeover value of 100.0 mg/dL). | Within Run (DxC 600 & 800): Max SD observed was 7.5 mg/dL (Serum Pool3 DxC 800) and max %CV was 3.6% (Serum Pool 1 DxC 600 & 800, Urine Pool 1 DxC 600, CSF Pool 1 DxC 600). Most values for samples >=100 mg/dL are well within claimed limits.

Total (DxC 600 & 800): Max SD observed was 9.4 mg/dL (Serum Pool3 DxC 800) and max %CV was 5.7% (Urine Pool 1 DxC 600). Most values for samples >=100 mg/dL are well within claimed limits.
(Performance across various sample types and concentrations generally meets or comes close to the claimed limits, with some low-concentration samples showing higher %CV as expected.) |
| Analytical Sensitivity | LoB, LoD, LoQ values ≤ 5 mg/dL. | LoB: Serum 0.19 mg/dL, CSF 0.17 mg/dL, Urine 0.19 mg/dL
LoD: Serum 1.74 mg/dL, CSF 1.68 mg/dL, Urine 1.78 mg/dL
LoQ: Serum 3.78 mg/dL, CSF 3.67 mg/dL, Urine 3.69 mg/dL
(All reported values are well below the 5 mg/dL criterion, indicating high sensitivity.) |
| Linearity | Linear between 5 and 700 mg/dL. | The data "substantiates GLUH test is linear between 5 and 700 mg/dL." Linear equations for DxC 600 and DxC 800 for Serum, CSF, and Urine demonstrate good linearity (slopes near 1 and small intercepts). |
| Interferences | Interference values ≤ ± 6 mg/dL or 10% (crossover value 60 mg/dL). | For low-level glucose pools, the mg/dL difference from target and % recovery (relative to 10% tolerance from 60 mg/dL) are generally within acceptable limits. For mid and high-level pools, % recovery values are consistently between 96.5% and 103.5%, mostly within 10% of target.
e.g., Hemoglobin (500 mg/dL), Bilirubin (24 mg/dL), Lipemia (3+/4+), Ascorbic Acid (6.0 mg/dL), Urea (500 mg/dL), Uric Acid (40 mg/dL), EDTA (16 mg/dL), Creatinine (40 mg/dL) all passed the interference criteria. |
| Reagent Stability | Stable on board for 30 days. | Testing established that the GLUH reagent is stable on board for 30 days. Recovered values fell within expected ranges over the testing period. |
| Calibration Stability | 14 days. | The assay was calibrated at 14-day intervals during reagent stability testing, implying successful performance over this period. |
| Sample Dilution | Saline chosen as appropriate diluent, no issues observed. | Saline was chosen as the appropriate diluent, and "there was no issue or effect observed when verifying saline as an appropriate sample diluent." |

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

• Method Comparison:
  • Serum (DxC 600 & 800): 120 samples each (total 240)
  • CSF (DxC 600 & 800): 100 samples each (total 200)
  • Urine (DxC 600 & 800): 117 samples each (total 234)
  • Total for Method Comparison: 674 samples.
• Anticoagulant Studies:
  • Sodium Heparin: 79 samples (DxC600), 58 samples (DxC800)
  • Lithium Heparin: 79 samples (DxC600), 58 samples (DxC800)
  • Sodium Fluoride/Potassium Oxalate: 79 samples (DxC600), 58 samples (DxC800)
  • Total for Anticoagulant Studies: (3 * 79) + (3 * 58) = 237 + 174 = 411 samples. (Stated "Over 50 patient specimens with glucose concentrations spanning the analytical range" for each anticoagulant type, then provides N for each DxC system. The cumulative N suggests that these are unique patient specimens across the anticoagulant types but not necessarily all unique for DxC600 vs DxC800)
• Precision: 80 data points for each sample type (Control 1, Control 2, Control 3, Pool 1, Pool 2, Pool 3) across Serum, Urine, and CSF, for both DxC 600 and DxC 800. This refers to the number of measurements rather than unique patient samples.
• Analytical Sensitivity (LoB, LoD, LoQ): "Multiple urine, CSF and serum pools were run over multiple days". Specific number of samples not given, but refers to "pools."
• Linearity: "Multiple replicates of the pools over the range of the assay." Specific number of samples not given, but refers to "pools."
• Interferences: "Patient serum pools" used for low, mid, and high glucose levels. Specific number of patient samples not given, but implies multiple pools.
• Data Provenance: The document explicitly states "patient correlation studies were conducted using... patient samples" and "paired plasma and serum samples from healthy volunteers." It doesn't specify country of origin but implies clinical laboratory settings. The studies are described as conducted by Beckman Coulter, Inc., suggesting internal testing. The nature of these studies (evaluating device performance against a predicate and known standards) indicates these are primarily prospective data collections for device validation.

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

This type of information (number and qualifications of experts) is generally not applicable or stated for in vitro diagnostic devices like a glucose reagent. The "ground truth" for clinical chemistry assays is established by the reference method (the predicate device in this case) and established analytical techniques and standards (e.g., standard concentrations, known interference levels). Medical professionals use the results, but they don't establish the "ground truth" for the device's technical performance.

4. Adjudication Method

Not applicable for this type of in vitro diagnostic device study. Adjudication methods are typically used in studies involving subjective interpretation, like image analysis by multiple readers.

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

No, an MRMC comparative effectiveness study was not done. This type of study involves human readers interpreting cases, often with and without AI assistance, which is not relevant for an automated glucose reagent.

6. Standalone (Algorithm Only) Performance

Yes, the studies described are for the standalone performance of the UniCel DxC SYNCHRON Systems Glucose reagent (GLUH) itself, as implemented on the UniCel DxC 600/800 SYNCHRON Systems. The performance data presented (precision, linearity, sensitivity, interference) are direct measurements of the reagent's analytical capability. The method comparison studies compare this standalone performance to that of a predicate device.

7. Type of Ground Truth Used

The ground truth for the test set was established using:

• Predicate Device Measurements: For method comparison, the predicate device (SYNCHRON Glucose (GLU) or GLUCm) provided the comparative truth.
• Known Concentrations/Reference Standards: For studies like linearity, precision, and analytical sensitivity, the ground truth was based on samples with precisely known glucose concentrations (e.g., control materials, spiked samples, dilutions of high-concentration samples).
• Spiked Samples: For interference studies, known interfering substances were added to patient serum pools to create controlled samples with expected values.
• Paired Samples: For anticoagulant studies, serum samples (representing the true value) were compared with plasma samples prepared with different anticoagulants.

8. Sample Size for the Training Set

This document only describes performance testing for device validation and substantial equivalence with a predicate device. It does not refer to a "training set" in the context of machine learning. The "training" for such an in vitro diagnostic device involves the chemical formulation of the reagent itself and the engineering of the analyzer system, which would be subject to extensive R&D and internal testing, but not typically documented as a distinct "training set" in this manner for regulatory submission.

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

As mentioned above, there isn't a "training set" in the machine learning sense for this device. The development and optimization of the reagent and system would rely on standard chemical and analytical laboratory practices to ensure accurate and reliable measurements.

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