FDA 510(k) Search - By Innolitics (SaMD and AI Experts)

GenChem ISE Electrolyte Buffer, when used in conjunction with the GenChem ISE Electrolyte Reference, GenChem CO2 Acid Reagent, GenChem CO2 Alkaline Buffer, GenChem Wash Concentrate, and appropriate Calibrators or Calibration Standards, is intended for the quantitative determination of sodium, potassium, chloride, and total CO2 in serum and plasma, and sodium, potassium and chloride in urine, and Reference will also determine calcium in serum, plasma and urine.

Sodium results are for the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by the destruction of the adrenal glands), dehvdration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance. Potassium results are used to monitor electrolyte imbalance in the diagnosis and treatment of diseases and conditions characterized by low or high blood potassium levels. Chloride results are used in the treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis. Carbon dioxide results are used in the diagnosis and treatment of numerous and potentially serious disorders associated with changes in the body's acid-base balance. Calcium results are used in the diagnosis and treatment of parathyroid diseases, chronic renal disease and tetany (intermittent muscular contractions or spasm).

Device Description

Sodium, Potassium, Chloride, CO2 and Calcium are determined by the use of Ion Specific Electrodes, the conductivity of which is proportional to the concentration of electrolyte in the sample which is mixed with high ionic strength buffer using the ISE Solution as the reference.

AI/ML Overview

This document describes the performance characteristics and acceptance criteria for the GenChem ISE Electrolyte Buffer, a device used for the quantitative determination of various electrolytes.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria for this device are demonstrated through its performance in precision, linearity, sensitivity, and patient comparison studies. The performance is compared to established methods using a predicate device (Beckman CX3 Synchron Analyzer). Given that this is a 510(k) summary for a reagent/buffer, the "acceptance criteria" are implied by the demonstration of performance that is substantially equivalent to a legally marketed predicate device. The values provided represent the device's reported performance which met the implicit acceptance for commercialization.

Performance Metric	Analyte	Acceptance Criteria (Implied by Predicate Equivalence)	Reported Device Performance
Precision	All Electrolytes	(Within-Day & Day-to-Day) – CV values and standard deviations should be comparable to the predicate device and within clinically acceptable limits for the respective analytes. (Specific numerical criteria are not explicitly stated as "acceptance criteria" but rather as results of testing for substantial equivalence).	Within-Day (N=60): Details are presented in a highly fragmented table. The text next to the tables appears to be OCR errors and garbled. However, the tables themselves, while presented poorly, likely contain the standard deviation (SD) and Coefficient of Variation (CV) for S-1, S-2, S-3 (presumably control levels), U-1, U-2. Day-to-Day (N=60): Similarly, data for S-1, S-2, U-1, U-2, S-3 are presented, presumably showing SD/CV. The data is unreadable in the provided text, but the study was conducted.
Linearity/Reportable Range	Calcium	Linear range should encompass clinically relevant values. The R2 value should be close to 1, indicating good linearity.	Range: 0.8 – 14.3 mg/dL. Intercept: 0.34, Slope: 0.911, R2: 1.000, Sey: 0.35.
	Sodium	Linear range should encompass clinically relevant values. The R2 value should be close to 1, indicating good linearity.	Range: 0 – 200 mmol/L. Intercept: 2.37, Slope: 0.968, R2: 1.000, Sey: 2.61.
	Potassium	Linear range should encompass clinically relevant values. The R2 value should be close to 1, indicating good linearity.	Range: 0.9 – 15.2 mmol/L. Intercept: -0.09, Slope: 1.017, R2: 1.000, Sey: 0.03.
	Chloride	Linear range should encompass clinically relevant values. The R2 value should be close to 1, indicating good linearity.	Range: 0 – 197 mmol/L. Intercept: -0.71, Slope: 0.999, R2: 1.000, Sey: 0.99.
	CO2	Linear range should encompass clinically relevant values. The R2 value should be close to 1, indicating good linearity.	Range: 0 – 40 mmol/L. Intercept: 0.15, Slope: 1.000, R2: 1.000, Sey: 0.41.
Sensitivity	Calcium	Limit of detection should be clinically acceptable.	Limit of Detection: 1.5 mg/dL.
	Sodium	Limit of detection should be clinically acceptable.	Limit of Detection: 10 mmol/L.
	Potassium	Limit of detection should be clinically acceptable.	Limit of Detection: 1.0 mmol/L.
	Chloride	Limit of detection should be clinically acceptable.	Limit of Detection: 15 mmol/L.
	Total CO2	Limit of detection should be clinically acceptable.	Limit of Detection: 5.0 mmol/L.
Patient Comparison	All Electrolytes	Comparison results (slope (m), intercept (b), correlation coefficient (r)) should demonstrate substantial equivalence to the predicate device. An 'r' value close to 1 indicates good correlation.	Calcium (Serum): n=80, m=0.989, b=0.0, r=0.985, Range=7.1-10.6.Calcium (Plasma): n=80, m=0.990, b=0.0, r=0.995, Range=7.1-10.7.Calcium (Urine): n=74, m=1.007, b=-0.2, r=0.998, Range=2.4-15.2.
Chloride (Serum): n=80, m=0.988, b=1.0, r=0.935, Range=98-127.
Chloride (Plasma): n=80, m=0.998, b=0.8, r=0.985, Range=98-127.
Chloride (Urine): n=78, m=1.049, b=-5.1, r=0.999, Range=22-289.
Chloride (CSF): n=44, m=1.024, b=-3.4, r=0.985, Range=113-152.
Potassium (Serum): n=80, m=0.969, b=0.13, r=1.000, Range=3.2-10.8.
Potassium (Plasma): n=80, m=0.987, b=0.15, r=1.000, Range=3.2-10.8.
Potassium (Urine): n=80, m=0.993, b=0.01, r=1.000, Range=3.5-136.
Sodium (Serum): n=80, m=0.930, b=9.1, r=0.938, Range=132-159.
Sodium (Urine): n=78, m=1.000, b=-0.3, r=1.000, Range=17-288.
Total CO2 (Serum): n=80, m=0.949, b=1.2, r=0.953, Range=9.5-29.
Total CO2 (Plasma): n=80, m=0.965, b=0.9, r=0.960, Range=9.5-29.

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

Precision (Test Set):
- Within-Day: N=60 for each analyte, across different control levels (S-1, S-2, S-3, U-1, U-2).
- Day-to-Day: N=60 measurements over 30 days for each analyte, across different control levels (S-1, S-2, U-1, U-2, S-3).
- Data Provenance: Not explicitly stated, but typically these types of studies use manufactured controls and spiked samples, likely performed within the manufacturer's laboratory or a designated testing facility. The document mentions "commercially available linearity standards" and "serum control."
Linearity (Test Set): Commercially available linearity standards were analyzed in triplicate. The exact number of distinct linearity standards (concentration points) is not specified, but typically involves at least 5-7 levels.
Sensitivity (Test Set): A serum control was repetitively assayed, and then diluted, with replicates of 10 runs to establish the limit of detection. The sample size for establishing the limit of detection for each analyte was 10 replicates.
Patient Comparison (Test Set):
- Serum, plasma, cerebrospinal fluid (CSF), and urine specimens were used.
- Calcium (Serum, Plasma): n=80 each.
- Calcium (Urine): n=74.
- Chloride (Serum, Plasma): n=80 each.
- Chloride (Urine): n=78.
- Chloride (CSF): n=44.
- Potassium (Serum, Plasma, Urine): n=80 each.
- Sodium (Serum): n=80.
- Sodium (Urine): n=78.
- Total CO2 (Serum, Plasma): n=80 each.
- Data Provenance: Collected from adult patients. No specific country of origin is mentioned, but typically this refers to a clinical site within the USA for FDA submissions. The study is prospective in the sense that these samples were collected and analyzed specifically for this comparison study, in parallel on both the predicate and test devices.

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

This type of device (electrolyte buffer for a clinical chemistry analyzer) does not typically involve human expert interpretation for "ground truth" establishment in the way that image analysis or diagnostic AI systems do. The "ground truth" for the test set is established by:

Reference Methods/Predicate Device: For the patient comparison study, the "ground truth" is the result obtained from the legally marketed predicate device (Beckman CX3 Synchron Analyzer), which is an established and accepted methodology for measuring these electrolytes.
Known Reference Materials: For precision, linearity, and sensitivity studies, the "ground truth" is derived from the known concentrations of commercially available control materials and linearity standards.

Therefore, there were no human "experts" with specific qualifications (like radiologists) involved in establishing ground truth in the context of interpretation, but rather the performance of an already-approved, established diagnostic device.

4. Adjudication Method for the Test Set

No adjudication method as typically understood in studies involving human interpretation (e.g., 2+1, 3+1) was used or is applicable for this type of in-vitro diagnostic device. The comparison is objective, based on quantitative measurements. For patient comparison, the results from the GenChem device were compared statistically (least squares linear regression) against the results from the Beckman CX3 Synchron Analyzer.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done

No MRMC comparative effectiveness study was done. This type of study is relevant for diagnostic imaging or interpretation tasks where human readers make subjective assessments (e.g., radiologists interpreting images). The GenChem ISE Electrolyte Buffer is an in-vitro diagnostic reagent/buffer for an automated analyzer, thus human interpretation is not the primary output being evaluated. The device's performance is objective (numeric measurements of analytes).

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done

Yes, the performance presented for precision, linearity, sensitivity, and patient comparison is standalone performance of the GenChem ISE Electrolyte Buffer when used with the specified analyzer (Beckman CX3 Synchron Analyzer and associated reagents). There is no "human-in-the-loop" component for the measurement process itself, other than the standard operation of the analyzer by trained lab personnel. The device itself (the buffer) is a reagent, not an algorithm, so the concept of an "algorithm only" performance applies to the entire analytical system with the new buffer.

7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)

The ground truth used for this device's validation is primarily:

Reference Measurement (Predicate Device): For patient comparison, the measurements obtained from the predicate Beckman CX3 Synchron Analyzer served as the reference standard.
Known Concentrations: For precision, linearity, and sensitivity, the known, assayed values of commercially available control materials and linearity standards were used.

There is no mention of expert consensus, pathology, or outcomes data being used to establish ground truth for the analytical performance of this IVD device.

8. The Sample Size for the Training Set

This document describes a pre-market notification (510(k)) for a medical device (reagent/buffer), not a machine learning or AI algorithm. Therefore, the concept of a "training set" in the context of AI is not applicable. The device's formulation and manufacturing processes are developed and optimized through R&D, but there is no "training phase" with a distinct dataset as there would be for an AI model.

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

As explained above, there is no "training set" in the AI sense for this device. The chemical and performance characteristics are established through standard chemical and analytical development processes, not through machine learning.

Summary

Regulation Number and Section

§ 862.1665 Sodium test system.

(a)
Identification. A sodium test system is a device intended to measure sodium in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.(b)
Classification. Class II.