(163 days)
The GemLyte is an automated, microprocessor-controlled analyzer which utilizes ion-selective electrodes for the measurement of sodium, potassium, chloride, calcium and lithium in whole blood, plasma and serum, and prediluted urine samples.
The GemLyte Potassium Assay is intended to measure potassium in whole blood, plasma, serum, and urine on the GemLyte Electrolyte Analyzer. Measurements obtained by this device are used to monitor electrolyte balance in the diagnosis and treatment of diseases conditions characterized by low or high blood potassium levels.
The GemLyte Sodium Assay is intended to measure sodium in whole blood, plasma, serum, and urine on the GemLyte Electrolyte Analyzer. Measurements obtained by this device are used to monitor electrolyte balance 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.
The GemLyte Chloride Assay is intended to measure the level of chloride in whole blood, plasma, serum, and urine. Chloride measurements are used in the diagnosis and treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis.
The GemLyte Calcium Assay is intended to measure the ionized calcium level in whole blood, plasma and serum. Calcium measurements are used in the diagnosis and treatment of parathyroid disease, a variety of bone diseases, chronic renal disease and tetany (intermittent muscular contractions or spasms).
The GemLyte Lithium Assay is intended to measure lithium (from the drug lithium carbonate) in whole blood, plasma and serum. Measurements of lithium are used to assure that the proper drug dosage is administered in the treatment of patients with mental disturbances, such as manic-depressive illness (bipolar disorder).
The GemLyte is an automated, microprocessor-controlled analyzer which utilizes ion-selective electrodes for the measurement of sodium, potassium, chloride, calcium and lithium in serum, plasma, whole blood and prediluted urine samples. GemLyte analyzer is designed with the user in mind, it is fully automated with simple .Yes' or 'No' commands for menu navigation. This simple interface insures that not only will the analyzer be easy to use for quick analysis, (less than a minute for samples), but also that the testing of samples can be done by even non-skilled operators with relative ease. The analyzer self-calibrates using Diamond Diagnostics Fluid Pack (510(k) 013850) every 4 hours through out the day or on request. Sodium, potassium, chloride and calcium are commonly measured for use in the diagnosis and management of patients with a broad range of renal, metabolic and cardiovascular disorders. Lithium is a drug used to treat mental illness. Mission controls (510 (k) 033063) are the recommended quality control material to be used daily.
The provided text describes the 510(k) summary for the GemLyte Electrolyte Analyzer. Here's a breakdown of the acceptance criteria and the study information as requested:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the GemLyte Electrolyte Analyzer are primarily based on achieving performance similar to or within specified limits of the predicate device (AVL 9180 (K961458)) and meeting internal reproducibility guidelines. The reported device performance metrics are presented as "reproducibility" (precision) and "correlation" (agreement with predicate device).
Acceptance Criteria (Performance Specifications)
| Metric | Parameter | Matrix | Acceptance Criteria (Internal/Predicate Comparison) | Reported Device Performance (Achieved) |
|---|---|---|---|---|
| Reproducibility (Precision) | ||||
| Within-Run | Na+ | Blood/Plasma/Serum | C.V. ≤1% | C.V. ≤0.6% |
| K+ | Blood/Plasma/Serum | C.V. ≤1.5% | C.V. ≤1.5% | |
| Cl- | Blood/Plasma/Serum | C.V. ≤2% | C.V. ≤1% | |
| Ca++ | Blood/Plasma/Serum | SD ≤0.02 | SD ≤0.02 | |
| Li+ | Blood/Plasma/Serum | SD ≤0.03 | SD ≤0.04 (Note: This is slightly higher than the specified SD ≤0.03 in the "Reproducibility" table but within the "Summary of nonclinical tests" table. The text states "Results are within performance specifications.") | |
| Na+ | Urine | C.V. ≤5% | C.V. ≤ 5% | |
| K+ | Urine | C.V. ≤5% | C.V. ≤ 5% | |
| Cl- | Urine | C.V. ≤5% | C.V. ≤ 2% (Note: This is better than the specified C.V. ≤ 5% in the "Reproducibility" table but within the "Summary of nonclinical tests" table. The text states "Results are within performance specifications.") | |
| Between-Run | Na+ | Serum/Blood/Serum | C.V. ≤2% | C.V. ≤1.5% |
| K+ | Serum/Blood/Serum | C.V. ≤3% | C.V. ≤3% | |
| Cl- | Serum/Blood/Serum | C.V. ≤3% | C.V. ≤3% | |
| Ca++ | Serum/Blood/Serum | SD ≤0.06 | SD ≤0.06 | |
| Li+ | Serum/Blood/Serum | SD ≤0.09 | SD ≤0.09 | |
| Na+ | Urine | C.V. ≤5% | C.V. ≤4% | |
| K+ | Urine | C.V. ≤5% | C.V. ≤5% | |
| Cl- | Urine | C.V. ≤5% | C.V. ≤3% | |
| Linearity | All | All claimed range | Correlation coefficients > 0.99 (regression analysis) | All correlation coefficients were greater than 0.99. |
| Correlation to Predicate Device | All | All sample types | Correlation coefficients > 0.99 (regression analysis) | "Regression analysis show good correlation to predicate devices for all sample types, whole blood, plasma, serum and urine with correlation coefficients typically greater than 0.99." Specific R² values are provided in the tables above, all of which are ≥0.9687 (Chloride in Serum). |
2. Sample Size Used for the Test Set and Data Provenance
The test set for the correlation studies used the following sample sizes:
- Whole Blood: Sodium (n=128), Potassium (n=112), Chloride (n=123), Calcium (n=124), Lithium (n=123)
- Plasma: Sodium (n=105), Potassium (n=107), Chloride (n=115), Calcium (n=123), Lithium (n=115)
- Serum: Sodium (n=122), Potassium (n=127), Chloride (n=125), Calcium (n=120), Lithium (n=131)
- Urine (Spot): Sodium (n=118), Potassium (n=108), Chloride (n=118)
Data Provenance: The document does not explicitly state the country of origin. It indicates that samples were "collected for testing on the GemLyte as well as another predicate device, the AVL 9180." The language used (e.g., "mmol/L") is standard for clinical chemistry. The study appears to be prospective in nature, as it describes a setup for collecting and testing samples on two devices for comparison.
For precision (reproducibility) studies:
- Within-Run: 30 replicates for each sample type (blood, serum, urine).
- Between-Run: 2 runs per day with 2 replicates per run for 10 days for each sample type.
- Potassium (Whole Blood Specific): Multiple instruments (4) tested over a period of an hour due to instability.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of device (electrolyte analyzer) does not typically rely on "expert" interpretation for ground truth, unlike imaging or diagnostic AI. The "ground truth" for the correlation study is the measurement obtained from the predicate device (AVL 9180), which is an established, legally marketed device for the same purpose. The text states, "Clinical testing was conducted to demonstrate the correlation of Diagnostics GemLyte Analyzer to predicate devices operated by trained personnel." It clarifies that the comparison device was operated by "trained personnel," implying standard laboratory practice, but does not specify "experts" in the sense of clinical specialists like radiologists.
4. Adjudication Method for the Test Set
Not applicable. As explained above, the ground truth is established by the predicate device's readings, not by expert consensus or adjudication. The study design is a direct comparison of measurements between two devices.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This is not an imaging or diagnostic AI device that involves human readers interpreting cases. It is an automated electrolyte analyzer.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, the studies presented are standalone performance evaluations for the GemLyte Electrolyte Analyzer. The device is an automated system; its performance is measured directly (e.g., reproducibility, linearity) and compared against a predicate device's measurements, not against human performance in a diagnostic reading task.
7. Type of Ground Truth Used
The ground truth for the clinical correlation studies was the measurements obtained from the predicate device, AVL 9180. For within-run precision, the ground truth is implicitly the true stable concentration within the sample, with the device aiming to measure it consistently. For linearity, the ground truth was prepared standard solutions (dilutions from starting stock solutions).
8. Sample Size for the Training Set
The document does not specify a separate "training set" in the context of an AI/ML model for this device. The GemLyte Electrolyte Analyzer is based on ion-selective electrode (ISE) technology, not machine learning. Therefore, it does not typically involve a "training set" in the computational sense. The device is calibrated using internal calibration solutions and Diamond Diagnostics Fluid Pack (510(k) 013850) as described in the calibration section.
9. How the Ground Truth for the Training Set Was Established
As there is no "training set" for an AI/ML model, this question is not applicable in the typical sense.
For the device's internal calibration, the "ground truth" would be the known concentrations of the calibration solutions, which are presumably traceable to established standards. The text states:
- "The analyzer self-calibrates using Diamond Diagnostics Fluid Pack (510(k) 013850) every 4 hours through out the day or on request."
- "The GemLyte performs a 2-point calibration (3-point calibration if lithium) every 4 hours or software permits calibration on demand. A 1-point calibration is performed automatically with each measurement."
§ 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.