(406 days)
The i-STAT CHEM8+ cartridge with the i-STAT 1 System is intended for use in the in vitro quantification of glucose, and creatinine in arterial or venous whole blood in point of care or clinical laboratory settings.
Glucose measurements are used in the diagnosis, monitoring, and treatment of carbohydrate metabolism disorders including, but not limited to, diabetes mellitus, neonatal hypoglycemia, and pancreatic islet cell carcinoma.
Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.
The i-STAT CHEM8+ test cartridge contains test reagents to analyze whole blood at the point of care or in the clinical laboratory for glucose and creatinine. The test is contained in a single-use, disposable cartridge. Cartridges require two to three drops of whole blood which are typically applied to the cartridge using a transfer device.
The i-STAT 1 Analyzer is a handheld, in vitro diagnostic analytical device designed to run only i-STAT test cartridges. The instrument interacts with the cartridge to move fluid across the sensors and generate a quantitative result (within approximately 2 minutes).
The i-STAT 1 System is comprised of the i-STAT 1 analyzer, the i-STAT test cartridges and accessories (i-STAT 1 Downloader/Recharger, electronic simulator and portable printer). The system is designed for use by trained medical professionals at the patient point of care or in the clinical laboratory and is for prescription use only.
The provided text describes the analytical performance studies for the i-STAT CHEM8+ cartridge with the i-STAT 1 System for measuring glucose and creatinine. While it details numerous performance characteristics, it does not explicitly state "acceptance criteria" for each test. However, the study design and "results met the acceptance criteria" statements imply that certain predefined thresholds were successfully achieved.
Let's break down the information available to address your request:
Acceptance Criteria and Reported Device Performance
The document doesn't provide a consolidated table of explicit acceptance criteria. Instead, it states that results "met the acceptance criteria" for linearity, and it outlines the method for identifying interference (difference between control and test samples outside of the allowed error (Ea)). For precision studies, statistical metrics like Total Standard Deviation (ST) and Coefficient of Variation (CV) are presented, and for method comparison, slope, intercept, and correlation coefficient (r) are given. The implied acceptance is that these values fall within acceptable ranges for a diagnostic device of this type.
Implied Acceptance Criteria and Reported Performance (derived from text):
| Performance Characteristic | Implicit Acceptance Criteria (based on common IVD standards) | Reported Device Performance (Summary) |
|---|---|---|
| Precision (Aqueous Materials) | Low CV values across levels (e.g., 500 mmHg for creatinine and 25 to >500 mmHg for glucose." | |
| Altitude | Correlation coefficient and slope results met acceptance criteria. | Creatinine: r 1.00, Slope 1.13 (up to 6367 feet) |
| Glucose: r 1.00, Slope 1.00 (up to 9523 feet) | ||
| Interference | Absence of significant interference; difference between control/test samples within allowed error (Ea). | Glucose: Lithium Bromide (≥ 11.8 mmol/L) increased results; Hydroxyurea (≥ 0.08 mmol/L) increased results. |
| Creatinine: Lithium Bromide (≥ 18.3 mmol/L) increased results; Hydroxyurea (≥ 0.03 mmol/L) increased results. (Other listed substances showed no interference). | ||
| Method Comparison (vs. Predicate) | High correlation (r), slope near 1, intercept near 0. | Glucose: N=185, Slope 0.98, Intercept 0.00, r 1.00 |
| Creatinine: N=180, Slope 1.043, Intercept -0.062, r 1.00 |
Study Details:
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Sample Size used for the Test Set and Data Provenance:
- Precision (Aqueous): N=80 or 81 for each level of Creatinine and Glucose. Data provenance is not specified (e.g., country of origin) but implied to be laboratory-based ("one site"). It is an analytical performance study, not a clinical study on patient samples.
- Precision (Whole Blood): Sample sizes vary per site and level (e.g., N=14 to N=21). The study used "venous whole blood (native or altered) samples." The study was conducted at "3 point of care sites."
- Linearity: Whole blood samples of "varying analyte levels" were prepared. Specific N not provided for this particular section.
- LoQ, LoB/LoD: Whole blood samples were "altered to low glucose" or "blank" concentrations. Specific N not provided for this section.
- Hematocrit Sensitivity: Three hematocrit levels evaluated across four glucose levels. Specific N not provided.
- Oxygen Sensitivity: High and low ranges of oxygen. Specific N not provided.
- Altitude: Not explicitly stated, but results given for "average measured altitude." Specific N not provided.
- Interference: Whole blood samples based on CLSI guidelines. Specific N not provided, but multiple substances tested.
- Method Comparison: N=185 for Glucose, N=180 for Creatinine. Used "Venous and arterial blood specimens" for the i-STAT device and "plasma specimens" for the predicate device. Data provenance is not specified.
Overall Provenance: The studies are "analytical performance" studies, primarily laboratory-based and conducted on various prepared or native samples. There is no indication of geographic origin or whether samples were retrospective or prospective, though for analytical performance, prospective collection for the purpose of the study is common.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This is an in vitro diagnostic (IVD) device. The "ground truth" for analytical performance studies is established by reference methods or highly accurate laboratory analyzers (the "comparative method"), not by human experts interpreting images or clinical outcomes. In this case, "ground truth" (or comparative method) for the method comparison study was the Beckman DxC, a laboratory analyzer.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable. This is an IVD device measuring analytes, not interpretations of images or clinical assessments requiring human adjudication.
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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 an IVD device for measuring chemical analytes in blood, not an imaging device assisted by AI to be read by human experts.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- The i-STAT device functions as a standalone analyzer that quantifies glucose and creatinine. The performance studies described (precision, linearity, LoQ, LoD, interference, method comparison) are standalone performance studies of the device's ability to measure these analytes. While a human initiates the test and interprets the quantitative result, the measurement process itself is automated (algorithm only).
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The type of ground truth used (expert concensus, pathology, outcomes data, etc):
- For the method comparison study, the ground truth was essentially the measurements from a legally marketed predicate device (Beckman DxC), which serves as the comparative method in analytical validation. For other analytical performance studies (precision, linearity, LoQ/LoD), the "ground truth" is based on the known concentrations of prepared reference materials or controls, or the statistical evaluation of repeated measurements of samples.
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The sample size for the training set:
- The documentation does not discuss a "training set" in the context of machine learning or AI models, as this is a traditional IVD device based on electrochemical principles, not an AI/ML device. Therefore, no separate training set is mentioned or applicable in the way it would be for an AI-powered diagnostic.
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How the ground truth for the training set was established:
- Not applicable, as there is no explicitly mentioned "training set" in the context of an AI/ML model for this traditional IVD device.
§ 862.1345 Glucose test system.
(a)
Identification. A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, and idiopathic hypoglycemia, and of pancreatic islet cell carcinoma.(b)
Classification. Class II (special controls). The device, when it is solely intended for use as a drink to test glucose tolerance, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.