(23 days)
Both electrolyte buffers are used to measure sodium, chloride, potassium, and carbon dioxide concentrations in serum or plasma, sodium, potassium, and chloride concentrations in urine, and chloride concentrations in CSF on the SYNCHRON CX 3 System
The Sigma Diagnostics methods use ion selective electrodes for determining sodium, potassium, and chloride and rate of pH change for determing carbon dioxide on the SYNCHRON CX 3 System.
The provided text describes the summary of safety and effectiveness for the Sigma Diagnostics CX®3 Electrolyte Buffer, Procedure Number E3766. It focuses on demonstrating substantial equivalence to a predicate device (Beckman Electrolyte Buffer Kit, Part No. 443325) through comparison studies, precision, and linearity.
Here's an analysis based on your requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the comparison to a predicate device, focusing on correlation coefficients, regression equations indicating agreement, and acceptable levels of precision and linearity.
| Test Aspect | Acceptance Criteria (Implied by Predicate Equivalence) | Reported Device Performance |
|---|---|---|
| Correlation to Predicate (Serum) | High correlation coefficients (e.g., typically >0.95 for quantitative assays) | Sodium: 0.963Potassium: 0.999Chloride: 0.973Total CO₂: 0.992 |
| Regression to Predicate (Serum) | Regression equation close to y = 1x + 0 (i.e., slope near 1, intercept near 0) | Sodium: y = 0.90x + 13.48Potassium: y = 0.98x + 0.08Chloride: y = 0.91x + 10.52Total CO₂: y = 0.95x + 1.54 |
| Correlation to Predicate (Urine) | High correlation coefficients (e.g., typically >0.95 for quantitative assays) | Sodium: 0.997Potassium: 0.998Chloride: 0.997 |
| Regression to Predicate (Urine) | Regression equation close to y = 1x + 0 | Sodium: y = 0.95x - 0.10Potassium: y = 0.97x + 0.49Chloride: y = 0.97x + 2.06 |
| Correlation to Predicate (CSF) | High correlation coefficient (e.g., typically >0.95) | Chloride: 0.891 |
| Regression to Predicate (CSF) | Regression equation close to y = 1x + 0 | Chloride: y = 0.98x + 4.00 |
| Precision (Serum) | Low %CVs (e.g., typically <5%, often <2% for electrolytes) | Sodium (%CV): <1.1%Potassium (%CV): <1.0%Chloride (%CV): <1.3% |
| Precision (Urine) | Low %CVs | Sodium (%CV): <1.2%Potassium (%CV): <1.6%Chloride (%CV): <1.9% |
| Precision (CSF) | Low %CVs | Chloride (%CV): <1.8% |
| Linearity (Serum) | Accurate measurement across a clinically relevant range | Sodium: 100.0 - 200.0 mmol/LPotassium: 1.00 - 15.00 mmol/LChloride: 50.0 - 200.0 mmol/LTotal CO2: 5.0 - 40.0 mmol/L |
| Linearity (Urine) | Accurate measurement across a clinically relevant range | Sodium: 10 - 200 mmol/LPotassium: 2 - 200 mmol/LChloride: 15 - 300 mmol/L |
| Linearity (CSF) | Accurate measurement across a clinically relevant range | Chloride: 50 - 200 mmol/L |
2. Sample size used for the test set and the data provenance
- Sample Size: The document does not explicitly state the sample size for the comparison studies. It only presents the correlation coefficients and regression equations, implying a dataset was used without specifying its size.
- Data Provenance: Not specified. It's unclear if the data is from a particular country, or if it's retrospective or prospective. Given the context of a 510(k) submission in 1996 for a U.S. company, it's likely that the data would be derived from U.S. sources, but this is an inference, not a stated fact.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This question is not applicable to this type of device and study. The "ground truth" for an electrolyte analyzer is typically established by measurements from a reference method or a legally marketed predicate device, not by expert consensus in the same way an imaging or diagnostic AI interpretation device would. In this case, the predicate device (Beckman Electrolyte Buffer Kit, Part No. 443325) served as the reference for comparison.
4. Adjudication method for the test set
Not applicable. As noted above, this study is comparing a new device to a predicate device, not involving human interpretation or adjudication in the typical sense.
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 a study for an in vitro diagnostic (IVD) reagent, not an AI-assisted diagnostic tool involving human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, in a sense, the entire study is "standalone" in that it assesses the performance of the Sigma Diagnostics Electrolyte Buffer on the SYNCHRON CX 3 System as an automated measurement system, without human intervention in the analytical measurement itself. The results (correlation, precision, linearity) directly reflect the algorithm's/device's performance.
7. The type of ground truth used
The "ground truth" was established by measurements obtained from a legally marketed predicate device, the Beckman Electrolyte Buffer Kit, Part No. 443325. This is a common and accepted method for demonstrating substantial equivalence for IVD devices.
8. The sample size for the training set
Not applicable. This device is not an AI/ML device that requires a "training set" in the conventional sense. The "training" or development of the reagent and its methods would have occurred internally at Sigma Diagnostics, but that's not a data set used to train an algorithm.
9. How the ground truth for the training set was established
Not applicable, as there is no "training set" for an AI/ML algorithm in this context.
{0}------------------------------------------------
SEP 2 7 1996
510(K) NOTIFICATION
Sigma Diagnostics 545 South Ewing Avenue St. Louis, MO 63103
CX®3 Electrolyte Buffer Procedure Number E3766 August 31, 1996
SUMMARY OF SAFETY AND EFFECTIVENESS
Increased sodium levels are seen in congestive heart failure, nephrosis, hyperlipidemia and hyperglycemia. Decreased levels can be observed with excessive sweating and vomiting, with different types of diabetes, and with use of diuretic drugs.
Increased potassium levels can be due to renal failure and decrease mineralocorticoid activity such as in Addison's disease. Decreased potassium levels can be caused by renal and adrenal conditions with metabolic alkalosis or acidosis.
Increased chloride levels may be due to hyperparathyroidism. Low levels may be due to Addison's disease, intestinal obstruction, rickettsial disease and Waterhouse-Friderichsen Syndrome.
The CO, content is decreased in metabolic acidosis and respiratory alkalosis, whereas the level is increased in metabolic alkalosis and respiratory acidosis.
The Sigma Diagnostics methods use ion selective electrodes for determining sodium, potassium, and chloride and rate of pH change for determing carbon dioxide on the SYNCHRON CX 3 System.
The safety and effectiveness of Sigma Diagnostics Electrolyte Buffer, Procedure Number E3766, are demonstrated by its substantial equivalency to Beckman Electrolyte Buffer Kit, Part No. 443325. Both electrolyte buffers are used to measure sodium, chloride, potassium, and carbon dioxide concentrations in serum or plasma, sodium, potassium, and chloride concentrations in urine, and chloride concentrations in CSF on the SYNCHRON CX 3 System, and the reaction principles for both reagents are identical. In comparison studies, the following data was obtained:
| Serum Analyte | Correlation Coefficient | Regression equation |
|---|---|---|
| Sodium | 0.963 | y = 0.90x + 13.48 |
| Potassium | 0.999 | y = 0.98x + 0.08 |
| Chloride | 0.973 | y = 0.91x + 10.52 |
| Total CO₂ | 0.992 | y = 0.95x + 1.54 |
| Urine Analyte | Correlation Coefficient | Regression equation |
| Sodium | 0.997 | y = 0.95x - 0.10 |
| Potassium | 0.998 | y = 0.97x + 0.49 |
| Chloride | 0.997 | y = 0.97x + 2.06 |
{1}------------------------------------------------
510(K) NOTIFICATION
Sigma Diagnostics 545 South Ewing Avenue St. Louis, MO 63103
CX®3 Electrolyte Buffer Procedure Number E3766 August 31, 1996
SUMMARY OF SAFETY AND EFFECTIVENESS(cont.)
| CSF Analyte | Correlation Coefficient | Regression equation |
|---|---|---|
| Chloride | 0.891 | $y = 0.98x + 4.00$ |
With-in run precision and total precision for sodium demonstrated %CV's of less than 1.1 % on serum samples and less than 1.2 % on urine samples. With-in run precision and total precision for potassium demonstrated %CV's of less than 1.0 % on serum samples and less than 1.6 % on urine samples. With-in run precision and total precision for chloride demonstrated %CV's of less than 1.3 % on serum samples, less than 1.9 % on urine samples, and less than 1.8 % on CSF samples. The Sigma Diagnostics Electrolyte Buffer has been determined to be linear to the following limits on the SYNCHRON CX 3 System:
| Analyte | Serum (mmol/L) | Urine (mmol/L) | CSF (mmol/L) |
|---|---|---|---|
| Sodium | 100.0 - 200.0 | 10 - 200 | NA |
| Potassium | 1.00 - 15.00 | 2 - 200 | NA |
| Chloride | 50.0 - 200.0 | 15 - 300 | 50 - 200 |
| Total CO2 | 5.0 - 40.0 | NA | NA |
§ 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.