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The i-STAT CG8+ cartridge with the i-STAT 1 System is intended for use in the in vitro quantification of H, partial pressure of oxygen (PO2), and partial pressure of carbon dioxide (PCO2) in arterial, venous, or capillary whole blood in point of care or clinical laboratory settings.

pH, PO2, and PCO2 measurements are used in the diagnosis, monitoring, and treatment of respiratory, metabolic and acid-base disturbances.

The i-STAT CG8+ cartridge is used with the i-STAT 1 analyzer as part of the i-STAT 1 System and contains test reagents to measure pH, partial pressure of oxygen (PO2), and partial pressure of carbon dioxide (PCO2) in arterial, venous or capillary whole blood.

The i-STAT 1 System is an in vitro diagnostic (IVD) medical device intended for the quantitative determination of various clinical chemistry tests contained within i-STAT cartridges using whole blood. The i-STAT 1 System consists of a portable blood analyzer (i-STAT 1 analyzer), single-use disposable test cartridges (i-STAT cartridges), liquid quality control and calibration verification materials, and accessories (i-STAT 1 Downloader/Recharger, i-STAT Electronic Simulator and i-STAT 1 Printer). The i-STAT 1 System, including the i-STAT CG8+ cartridge, is designed for use by trained medical professionals in point of care or clinical laboratory settings and is for prescription use only.

The i-STAT CG8+ cartridge contains the required sensors, a fluid pack (calibrant pouch), a sample entry well and closure, fluid channels, waste chamber, and the necessary mechanical features for controlled fluid movement within cartridge. The i-STAT cartridge format allows all the tests in the cartridge to be performed simultaneously. All the test steps and fluid movement occur within the i-STAT CG8+ cartridges require two to three drops of whole blood applied to the cartridge using a transfer device by the trained user before the cartridge is placed within the analyzer.

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 i-STAT CG8+ cartridge to move fluid across the sensors and generate a quantitative result (within approximately 2 minutes).

The provided text describes the analytical performance and comparison studies for the Abbott i-STAT CG8+ cartridge with the i-STAT 1 System, specifically for pH, PO2, and PCO2 measurements. It does not contain information about the establishment of ground truth by expert readers, multi-reader multi-case (MRMC) studies, or the training set for an AI/ML device. This document is a 510(k) summary for an in vitro diagnostic device, not an AI/ML-driven device.

Therefore, the following information cannot be extracted from the given text:

• Number of experts used to establish the ground truth.
• Qualifications of those experts.
• Adjudication method for the test set.
• Multi-reader multi-case (MRMC) comparative effectiveness study, effect size of human readers improving with AI vs without AI assistance.
• Standalone (algorithm only without human-in-the-loop performance) study.
• Type of ground truth (expert consensus, pathology, outcomes data, etc.) as the ground truth is established by a comparative method (predicate device or standard laboratory methods) for analytical performance.
• Sample size for the training set.
• How ground truth for the training set was established.

However, I can extract information related to acceptance criteria (implied by the study results meeting certain performance metrics) and the study that proves the device meets those criteria for the i-STAT CG8+ cartridge.

Here's a breakdown of the available information:

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state "acceptance criteria" in a separate table for each test, but rather presents performance data (precision, linearity, detection limits, interference, method comparison) which are implicitly compared against pre-defined acceptance criteria (not explicitly listed but implied by the "met acceptance criteria" statements in the Altitude study and the overall conclusion of substantial equivalence).

Based on the provided data, here's a representation for the key performance metrics.
The acceptance criteria are implicitly met if the reported performance supports substantial equivalence.

• pH: Within-Laboratory SD up to 0.00482 pH units (0.07% CV).
• PO2: Within-Laboratory SD up to 10.80 mmHg (2.91% CV).
• PCO2: Within-Laboratory SD up to 1.307 mmHg (1.48% CV).
  Multi-Site/Operator (Table 3):
• pH: Overall SD up to 0.00579 pH units (0.09% CV).
• PO2: Overall SD up to 12.24 mmHg (4.07% CV).
• PCO2: Overall SD up to 1.489 mmHg (3.63% CV). |
  | Precision (Whole Blood)| Demonstrate consistent reproducibility across different blood sample types (venous, arterial, capillary). | Whole Blood Precision (Table 4):
• pH: %CV from 0.04% to 0.08% for venous/arterial, up to 0.34% for capillary.
• PO2: %CV from 0.97% to 4.18% for venous/arterial/capillary (excluding N/A ranges). Capillary PO2 up to 10.65% CV.
• PCO2: %CV from 0.65% to 2.85% for venous/arterial, up to 6.56% for capillary. |
  | Linearity | Demonstrate linearity over the specified reportable range. | Regression Summary (Table 5):
• pH: Slope 1.011, Intercept -0.098, R² 0.9994 (Range Tested: 6.4290 – 7.8522 pH units).
• PO2: Slope 0.977, Intercept 1.062, R² 0.9956 (Range Tested: 4.4 – 700.0 mmHg).
• PCO2: Slope 1.029, Intercept -1.144, R² 0.9991 (Range Tested: 2.40 – 148.38 mmHg).
  "demonstrated linearity over the reportable range for each i-STAT test." |
  | Limit of Quantitation (LoQ)| LoQ to be at or below the lower limit of the reportable range. | Summary of LoQ Results (Table 6):
• pH: Lower limit 6.500, Determined LoQ 6.464.
• PO2: Lower limit 5, Determined LoQ 5.
• PCO2: Lower limit 5.0, Determined LoQ 3.2. |
  | Analytical Specificity (Interference) | No significant interference from specified substances at toxic/pathological concentrations. | Potentially Interfering Substances (Table 7):
  No interference identified for pH, PO2, and PCO2 from Acetaminophen, Atracurium, Bilirubin, Calcium, Ethanol, Hemoglobin, Ibuprofen, Intralipid 20%, Morphine, Potassium, Sodium, Thiopental, Triglyceride at specified concentrations. |
  | Altitude Performance | Equivalent performance between candidate and comparator conditions at approximately 10,000 feet above sea level. | Summary of Altitude Study Results (Table 8):
• pH: r=1.00, Slope=0.99 (95% CI 0.984 to 0.998).
• PO2: r=1.00, Slope=1.02 (95% CI 1.000 to 1.037).
• PCO2: r=1.00, Slope=0.98 (95% CI 0.969 to 0.989).
  "met acceptance criteria and demonstrated equivalent performance". |
  | Method Comparison (vs. Predicate) | High correlation (r) and acceptable bias at medical decision levels when compared to the predicate device. | Pooled Data (Table 9):
• pH: N=468, r=0.99, Slope=1.00, Intercept=0.00. Bias at MDLs: -0.0040.
• PO2: N=461, r=0.99, Slope=1.03, Intercept=-0.72. Bias at MDLs: 0.1 to 0.9.
• PCO2: N=465, r=0.97, Slope=1.08, Intercept=-1.13. Bias at MDLs: 1.79 to 4.71.
  Capillary Only (Table 10 & 11):
• pH: N=195, r=0.98, Slope=1.02, Intercept=-0.11. Bias at MDLs: -0.0160 to -0.0041 (native N=179).
• PO2: N=190, r=0.99, Slope=1.02, Intercept=-1.75. Bias at MDLs: -1.8 to -0.7 (native N=175).
• PCO2: N=189, r=0.97, Slope=1.09, Intercept=-1.90. Bias at MDLs: 1.17 to 3.36 (native N=179). |
  | Matrix Equivalence | Demonstrate acceptable equivalence between anticoagulated and non-anticoagulated specimens. | Matrix Equivalence (Table 12):
• pH: N=241, r=0.98, Slope=0.97, Intercept=0.19.
• PO2: N=241, r=0.98, Slope=0.94, Intercept=1.28.
• PCO2: N=241, r=0.96, Slope=1.02, Intercept=-0.23. |

2. Sample sizes used for the test set and the data provenance

• Precision Studies (Aqueous):
  • 20-day precision: N=80 for each fluid level (5 levels per analyte). Provenance not explicitly stated, but typically conducted in-house by the manufacturer.
  • Multi-site/Operator precision: N=90 or N=96 for each fluid level (5 levels per analyte). Conducted at three (3) sites. Provenance not explicitly stated (e.g., country of origin), assumed to be domestic (US) unless otherwise specified.
• Precision Study (Whole Blood): Sample sizes vary by analyte and sample type/range, ranging from N=0 (N/A) to N=108. Collected across multiple point-of-care sites. Provenance not explicitly stated. These are retrospective or newly collected clinical samples used for analytical testing.
• Linearity Study: "whole blood samples of varying analyte levels for each i-STAT test." Specific N not provided for linearity, but likely a smaller set sufficient to cover the range.
• Detection Limit (LoQ) Study: "two (2) i-STAT CG8+ cartridge lots and whole blood that was altered to a low analyte level". Specific N not provided, but typically involves repeat measurements.
• Interference Study: "whole blood samples." Specific N not provided for interference testing.
• Altitude Study: "whole blood samples at relevant analyte levels across the reportable range for each test." Specific N not provided for altitude study.
• Method Comparison Study:
  • Pooled (Arterial/Venous/Capillary): N=468 (pH), 461 (PO2), 465 (PCO2). Specimens collected across multiple point-of-care sites.
  • Capillary only: N=195 (pH), 190 (PO2), 189 (PCO2). This set includes native and contrived samples.
  • Native Capillary only bias: N=179 (pH), 175 (PO2), 179 (PCO2). Specimens collected from skin puncture.
  • Data provenance: "collected across multiple point of care sites," implying prospective collection of patient samples for these comparison studies. Country of origin not specified, but usually US for FDA submissions. The studies reference CLSI guidance documents.
• Matrix Equivalence Study: N=241. "non-anticoagulated venous and arterial whole blood specimens."

All studies appear to be prospective data collection or laboratory studies designed for validation, based on the testing methodologies described (e.g., CLSI guidelines, collection of new samples).

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not applicable. This is an in vitro diagnostic device measuring objective physiological parameters (pH, PO2, PCO2). The "ground truth" or comparative value for these measurements is established by a "comparative method" (RAPIDPoint 500/500e, which is another blood gas analyzer) or by standard reference methods/materials (e.g., NIST SRMs, tonometered aqueous standards). There is no human interpretation or expert consensus involved in determining the "truth" for these quantitative chemical measurements.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable, as ground truth is not established by human readers requiring adjudication.

5. 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 device is not an AI/ML device that assists human readers. It is an IVD for direct measurement of blood gas parameters.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This device is a measurement system; its performance is inherently "standalone" in that it produces a quantitative result without human-in-the-loop interpretation of images or complex data patterns. It outputs a direct measurement.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The "ground truth" for the device's measurements (pH, PO2, PCO2) is established by:

• Reference materials/standards: NIST SRMs and certified specialty medical gas tanks for traceability and calibration (Section VI, Traceability).
• Comparative method: The predicate device, the Siemens RAPIDPoint 500e Blood Gas System, or the RAPIDPoint 500/500e in general, for method comparison studies (Section VII.B.a). This is considered a highly accurate and established method for these analytes.
• Internal reference: For "other sensitivity studies" like Altitude, the i-STAT CG4+ (blue) cartridges on the i-STAT 1 analyzer served as a comparator device.

8. The sample size for the training set

Not applicable. This is not an AI/ML device that requires a "training set" in the machine learning sense. The device is based on established electrochemical principles, and its performance is validated through analytical studies.

9. How the ground truth for the training set was established

Not applicable, as there is no "training set." The device is calibrated using reagents contained within the cartridge, traceable to known standards (NIST SRMs).

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