(231 days)
The i-STAT Alinity System with i-STAT Sodium test is intended for use or clinical laboratory settings. The i-STAT Alinity System with Sodium test is intended for the quantitative measurement of sodium in arterial and venous whole blood.
Sodium measurements are used for monitoring electrolyte imbalances.
For in vitro diagnostic use.
The i-STAT Alinity System is a handheld, in vitro diagnostic analytical device designed to run i-STAT test cartridges. The system is designed for use at or near point of patient care, by trained medical professionals and is for prescription use only and is for use in point of care and laboratory settings.
The i-STAT Alinity System is comprised of the instrument, rechargeable battery, base station, electronic simulator, control material, printer and i-STAT test cartridges. The i-STAT Alinity Instrument features a barcode scanner, user interface with touch screen display and wireless capability. The instrument reports quantitative results within approximately 2 minutes.
The i-STAT cartridge contains test reagents which are located on the biosensors chips. The instrument interacts with the cartridge to move fluid across the biosensors and generate a quantitative result. Cartridges require two to three drops of whole blood which are typically applied to the cartridge using a syringe.
Here's an analysis of the provided text regarding the acceptance criteria and study for the i-STAT Alinity System with i-STAT Sodium test:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state formal "acceptance criteria" for each performance characteristic in a table format. However, the performance studies report findings that implicitly serve as evidence that the device meets certain quality standards. I will infer the implied acceptance criteria based on the reported results and common professional standards for in vitro diagnostic devices.
| Performance Characteristic | Implied Acceptance Criteria (Inferred from Study Design/Common Standards) | Reported Device Performance | Meets Criteria? |
|---|---|---|---|
| Precision (Aqueous Materials) | Within-run, between-run, and total precision (SD/%CV) should be minimal and acceptable for clinical use. | Max Total SD: 0.96 mmol/L; Max Total %CV: 0.60% (CV L4) | Yes (suggests good precision) |
| Precision (Whole Blood) | Within-instrument and total precision (SD/%CV) should be minimal and acceptable for clinical use across different concentration levels and sites. | Largest estimate of precision: 0.50 mmol/L (SD) / 0.43% (CV) | Yes (suggests good precision) |
| Linearity | Device should show linearity (or acceptable non-linearity) across the reportable range. | Non-linearity ranged from -0.40 to 0.66 mmol/L over reportable range (100 - 180 mmol/L). A second-order model was the best fit. | Yes (demonstrated linearity over the range) |
| Recovery | % Recovery should be close to 100%. | Ranged from 99.9% to 100.6%. | Yes (excellent recovery) |
| Limit of Quantitation (LoQ) | LoQ should be clinically relevant and accurately determined. | Determined to be 80 mmol/L. | Yes (a specific LoQ was established) |
| Interference | Minimal or no interference from common endogenous and exogenous substances; interfering substances should be identified. | Table 3 lists 18 non-interfering compounds at specified concentrations. Table 4 identifies Bromide (>16.65 mmol/L) and Sodium Thiosulfate (>3.57 mmol/L) as interfering, with quantitative effects. | Yes (interfering substances were identified and quantified) |
| Anticoagulant Study | Performance should be comparable between different sample types (e.g., heparinized vs. non-anticoagulated whole blood). | Deming regression: slope of 1.00, correlation coefficient of 1.00 (between heparinized and non-anticoagulated whole blood). | Yes (performance is comparable) |
| Method Comparison with Predicate Device | Performance should be substantially equivalent to the predicate device. | Weighted Deming regression: slope of 1.0, correlation coefficient of 0.999. | Yes (demonstrates substantial equivalence) |
2. Sample Size Used for the Test Set and Data Provenance
- Precision (Aqueous Materials): 80 tests per level (N=80) for 5 levels.
- Precision (Whole Blood): 21 test results per sample for each of the 3 samples (total 63 tests per site, across 3 sites). The document refers to "venous whole blood (native or altered) samples."
- Linearity: Not explicitly stated, but "a series of sodium concentration levels in whole blood."
- Recovery: "a series of sodium concentration levels in whole blood."
- Limit of Quantitation (LoQ): Not explicitly stated, but "whole blood that was altered to low sodium concentrations (
§ 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.