(74 days)
The Poly-Chem 90 ISE Module is for the quantitative in vitro measurement of sodium, potassium, and chloride in human serum on the Poly-Chem 90 clinical chemistry analyzer.
Sodium measurements 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.
Potassium measurements are used to monitor electrolyte balance in the diagnosis and treatment of diseases conditions characterized by low or high blood potassium levels.
Chloride measurements are used in the diagnosis and treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis.
Poly-Chem 90 ISE Module is for the quantitative in vitro measurement of the level of sodium, potassium and chloride in human serum on the Poly-Chem 90 clinical chemistry analyzer. The ISE module measures sodium, potassium and chloride using ion selective electrode technology.
Here's an analysis of the Poly-Chem 90 ISE Module's acceptance criteria and the study proving it meets those criteria, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the Poly-Chem 90 ISE Module appear to be established by demonstrating substantial equivalence to the predicate device (Randox RX Daytona ISE Module) across various performance characteristics. While explicit numerical "acceptance criteria" are not stated as pass/fail thresholds independent of the predicate, the comparison implicitly sets the predicate's performance as the benchmark.
| Performance Characteristic | Acceptance Criteria (Implicit by Predicate Performance) | Poly-Chem 90 ISE Module Performance |
|---|---|---|
| Precision (Sodium) | Intraassay %CV: 0.52-0.75% | |
| Interassay %CV: 0.90-1.28% | Intraassay %CV: 0.06-0.27% | |
| Interassay %CV: 0.28-0.94% | ||
| Precision (Potassium) | Intraassay %CV: 0.39-0.54% | |
| Interassay %CV: 1.43-1.63% | Intraassay %CV: 0.14-0.33% | |
| Interassay %CV: 0.43-1.08% | ||
| Precision (Chloride) | Intraassay %CV: 0.53-0.82% | |
| Interassay %CV: 0.97-1.02% | Intraassay %CV: 0.08-0.54% | |
| Interassay %CV: 0.33-1.20% | ||
| Measuring Range (Na) | 20 - 200 mmol/L | 33.5 - 191.6 mmol/L |
| Measuring Range (K) | 0.2 - 20 mmol/L | 0.5 - 9.98 mmol/L |
| Measuring Range (Cl) | 25 - 200 mmol/L | 41.0 - 169.8 mmol/L |
| Method Comparison (Na) | $y = 0.91x + 8.60, r^2 = 0.99$ | $y = 1.04x - 5.06, r = 0.9929$ |
| Method Comparison (K) | $y = 0.97x + 0.09, r^2 = 0.99$ | $y = 0.99x + 0.02, r = 0.9982$ |
| Method Comparison (Cl) | $y = 0.98x - 0.27, r^2 = 0.99$ | $y = 1.01x - 1.64, r = 0.9985$ |
| Linearity (Na) | Not explicitly stated as acceptance criteria, but demonstrated for predicate. | Slope: 0.99 (0.97 to 1.00), Intercept: 0.09 (-1.92 to 2.11), r2: 0.9989 (Range: 30.4 - 191.6 mmol/L) |
| Linearity (K) | Not explicitly stated as acceptance criteria, but demonstrated for predicate. | Slope: 0.98 (0.98 to 0.99), Intercept: 0.17 (0.13 to 0.21), r2: 0.9998 (Range: 1.09 – 9.98 mmol/L) |
| Linearity (Cl) | Not explicitly stated as acceptance criteria, but demonstrated for predicate. | Slope: 1.02 (1.00 to 1.04), Intercept: -5.35 (-7.62 to -3.07), r2: 0.9989 (Range: 31.3 - 169.8 mmol/L) |
| Sensitivity | Not explicitly stated in comparison table for predicate. | LoB: Na 32.4, K 0.35, Cl 40.2 mmol/L |
| LoD: Na 33.5, K 0.393, Cl 41.0 mmol/L | ||
| LoQ: Na 32.5, K 0.5, Cl 40.8 mmol/L | ||
| Interference | Not explicitly stated in comparison table for predicate. | Up to: Hemoglobin 800 mg/dL, Bilirubin 7.5-25 mg/dL, Triglyceride 549-663 mg/dL |
| Intended Use | For quantitative in vitro measurement of Na, K, Cl in human serum, plasma, and urine on RX Daytona analyzer. | For quantitative in vitro measurement of Na, K, Cl in human serum on Poly-Chem 90 analyzer. |
| Indications for Use | Same as Poly-Chem 90 ISE Module (detailed list for Na, K, Cl). | Same as Predicate. |
| Sample Type | Serum, plasma, urine | Serum |
| Methodology | Ion selective electrode | Ion selective electrode |
2. Sample Sizes Used for the Test Set and Data Provenance
The document provides sample sizes for the method comparison studies (where the device is compared to the predicate), which can be considered part of the test set:
- Sodium (Na): 63 samples
- Potassium (K): 74 samples
- Chloride (Cl): 74 samples
The precision, linearity, and sensitivity tests also involved samples, but the exact number of unique patient samples isn't specified in detail beyond "Samples from [range] mmol/L" for precision.
Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. It only mentions the measurement of levels in "human serum."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. For an in vitro diagnostic device like this, "ground truth" would typically refer to the reference method (the predicate device in this case, or a gold standard method) rather than expert interpretation of images or clinical data. There is no mention of human experts being involved in establishing the "ground truth" for the performance characteristics of this chemical analyzer.
4. Adjudication Method for the Test Set
This is not applicable as the ground truth is established by chemical measurement, not through expert review and adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A MRMC comparative effectiveness study is not applicable to this type of device (in vitro diagnostic for chemical analysis). This study design is typically used for imaging diagnostics where human readers interpret results, often with and without AI assistance.
6. Standalone Performance
Yes, a standalone performance evaluation was done. The precision, linearity, and sensitivity studies presented in the "Summary of performance testing" section (pages 3-4) directly demonstrate the performance of the Poly-Chem 90 ISE Module itself, without comparison to the predicate. The method comparison studies (page 4) also provide the device's measurements, which are then compared to the predicate, implicitly showing its standalone output.
7. Type of Ground Truth Used
The "ground truth" for evaluating this device's performance appears to be primarily:
- Reference measurements/Method comparison: The predicate device (Randox RX Daytona ISE Module) serves as the comparator for method comparison studies, implying that its measurements are considered the "truth" for this comparison.
- Established analytical methods: For precision, linearity, and sensitivity, the ground truth is based on the inherent principles of analytical chemistry and expected performance characteristics for such assays. For example, linearity is assessed against a theoretical linear response, and precision against statistical variability.
8. Sample Size for the Training Set
The document does not provide information about a specific "training set" or its sample size. This device is an in vitro diagnostic analyzer, not an AI/ML algorithm that typically undergoes a distinct training phase on a dataset. Its performance is characterized through analytical validation studies (precision, linearity, etc.), not a machine learning training process.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a "training set" in the context of an AI/ML algorithm, this question is not applicable. The device's operational parameters and calibration are established through standard analytical chemistry principles and calibration procedures (e.g., using Medica Calibrator A and B, as mentioned) during its manufacturing and setup, not through a data-driven training process.
§ 862.1600 Potassium test system.
(a)
Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. 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.(b)
Classification. Class II.