(50 days)
The level of blood urea nitrogen (BUN) is regulated by the metabolism of proteins and by the renal excretion of urea. BUN determination, therefore, has become the most widely used screening procedure for evaluating kidney function. Increased BUN levels occur in cases of impaired kidney function such as chronic nephritis, acute glomerulonephritis, polycystic disease of the kidney, nephrosclerosis and tubular necrosis. BUN levels are also elevated due to urinary tract obstruction and during the terminal stage of liver disease. Decrease in BUN levels often accompany primary hepatic insufficiency and acute hepatitis.
The Sigma Diagnostics BUN Reagent is formulated to use this methodology on the SYNCHRON CX 3 System.
This document describes a diagnostic reagent, the Sigma Diagnostics BUN Reagent, and its performance in measuring blood urea nitrogen (BUN) levels. It is not an AI/ML device, and therefore several of the requested categories are not applicable. I will provide information for the relevant categories based on the provided text.
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Substantial Equivalency to Beckman BUN Reagent Kit | Achieved; "The safety and effectiveness of Sigma Diagnostics BUN Reagent... are demonstrated by its substantial equivalency to Beckman BUN Reagent Kit, Part No. 443350." |
| Identical Reaction Principles | Achieved; "reaction principles for both are identical." |
| Correlation Coefficient (vs. Beckman BUN Reagent Kit) | 0.999 |
| Regression Equation (vs. Beckman BUN Reagent Kit) | y = 1.03x - 0.19 |
| Within-run precision (%CV) | Less than 4% |
| Total precision (%CV) | Less than 4% |
| Linearity | To 125 mg/dL |
2. Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated as a number of samples. The text mentions "serum samples" were used for the comparison study and precision evaluations.
- Data Provenance: Not specified, but implied to be from clinical laboratory testing given the nature of the device (BUN reagent). Retrospective or prospective is not stated.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This is a chemical reagent, not an AI/ML device relying on human interpretation of images or other subjective data. The "ground truth" for this device would be established by reference methods or validated comparative methods.
4. Adjudication method for the test set:
- Not applicable. There is no subjective interpretation involved that would require adjudication.
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:
- Not applicable. This is not an AI/ML device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is a chemical reagent, not an algorithm. Its performance is measured directly on laboratory analyzers. The "standalone" performance here refers to its ability to accurately measure BUN concentrations.
7. The type of ground truth used:
- The "ground truth" for evaluating the Sigma Diagnostics BUN Reagent's performance was its comparison against the Beckman BUN Reagent Kit, Part No. 443350, which served as the reference or comparative method for establishing substantial equivalency. Reference methods and established clinical chemistry principles form the basis of ground truth for chemical assays.
8. The sample size for the training set:
- Not applicable. Reagents do not have "training sets" in the AI/ML sense. Their formulation and performance are optimized through chemical and analytical development.
9. How the ground truth for the training set was established:
- Not applicable. There is no training set in the AI/ML context for this device.
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OCT 2 4 996
510(K) NOTIFICATION
Sigma Diagnostics 545 South Ewing Avenue St. Louis, MO 63103
CX®3 BUN Reagent Procedure Number B1657 August 31, 1996
SUMMARY OF SAFETY AND EFFECTIVENESS
The level of blood urea nitrogen (BUN) is regulated by the metabolism of proteins and by the renal excretion of urea.1 BUN determination, therefore, has become the most widely used screening procedure for evaluating kidney function. Increased BUN levels occur in cases of impaired kidney function such as chronic nephritis, acute glomerulonephritis, polycystic disease of the kidney, nephrosclerosis and tubular necrosis.2 BUN levels are also elevated due to urinary tract obstruction and during the terminal stage of liver disease. Decrease in BUN levels often accompany primary hepatic insufficiency and acute hepatitis.
In 1961, Chin and Kroontje reported a method for determining urea based upon the difference in conductivity of urea and the ammonium bicarbonate produced by urease form urea.3 In 1971, the method was modified to detect urea by measuring the rate of increase of conductivity.4 The Sigma Diagnostics BUN Reagent is formulated to use this methodology on the SYNCHRON CX 3 System.
The safety and effectiveness of Sigma Diagnostics BUN Reagent, Procedure Number B1657, are demonstrated by its substantial equivalency to Beckman BUN Reagent Kit, Part No. 443350. Both reagents are used to measure BUN concentrations in serum or plasma on the SYNCHRON CX 3 System, and the reaction principles for both are identical. In a comparison study, a correlation coefficient of 0.999 and a regression equation of y = 1.03x - 0.19 was obtained with serum samples. With-in run precision and total precision on serum samples demonstrated %CV's of less than 4%. The Sigma Diagnostics BUN Reagent has been determined to be linear to 125 mg/dL.
REFERENCES
- 1 . Cantarow A Trumper M: Clinical Biochemistry, WB Saunders Company, Philadelphia, 1975. pp 207-209
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- Tietz NW: Fundamentals of Clinical Chemistry, WB Saunders Company, Philadelphia, 1976, p 993
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- Textbook of Clinical Chemistry, NW Tietz, Editor, WB Saunders Company, Philadelphia. 1986
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- Chin WT, Kroontje W: Anal Chem 33:1757, 1961
§ 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.