i-STAT CHEM8+ cartridge with the i-STAT 1 System

• K Number: K191360
• Device Name: i-STAT CHEM8+ cartridge with the i-STAT 1 System
• Manufacturer: Abbott Point of Care, Inc.
• Date Cleared: 2020-02-14 ( 269 days)
• Product Code: JFP
• Regulation Number: 862.1145
• Type: Traditional
• Panel: CH
• Reference & Predicate Devices: K061597

Intended Use

The i-STAT CHEM8+ cartridge with the i-STAT 1 System is intended for use in the in vitro quantification of ionized calcium in arterial or venous whole blood in point of care or clinical laboratory settings.

Ionized calcium measurements are used in the diagnosis and treatment of parathyroid disease, a variety of bone diseases, chronic renal disease and tetany.

Device Description

The i-STAT CHEM8+ test cartridge contains test reagents to analyze whole blood at the point of care or in the clinical laboratory for ionized calcium (iCa). 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.

AI/ML Overview

The provided text is a 510(k) summary for the i-STAT CHEM8+ cartridge with the i-STAT 1 System, specifically for the ionized calcium (iCa) test. It details various performance characteristic studies to demonstrate substantial equivalence to a predicate device.

Here's an analysis of the acceptance criteria and the study that proves the device meets them, based only on the provided text. Many elements cannot be fully answered as they are not explicitly stated in this specific document, which is a summary.

Acceptance Criteria and Reported Device Performance

The acceptance criteria are generally implied by the successful outcomes of the performance studies. For a clearer table, we derive the 'acceptance criteria' from the observed 'performance' meeting regulatory expectations for substantial equivalence.

Performance Characteristic	Acceptance Criteria (Implied)	Reported Device Performance
Precision (Aqueous Materials)	Low %CV values, indicating reproducibility across various levels and within/between runs/days.	iCa (mmol/L):

• CV L1: Total CV 0.6%
• CV L2/Control L1: Total CV 0.7%
• CV L3/Control L2: Total CV 0.5%
• CV L4/Control L3: Total CV 0.5%
• CV L5: Total CV 1.5% |
  | Precision (Whole Blood - Venous) | Low %CV values across different sample ranges. | Venous Whole Blood:
• 0.25-0.75 mmol/L: 2.2% CV
• 0.75-1.2 mmol/L: 1.6% CV
• 1.2-1.5 mmol/L: 1.0% CV
• 1.5-2.5 mmol/L: 0.9% CV |
  | Precision (Whole Blood - Arterial) | Low %CV values across different sample ranges. | Arterial Whole Blood:
• 0.25-0.75 mmol/L: 0.9% CV
• 0.75-1.2 mmol/L: 3.0% CV
• 1.2-1.5 mmol/L: 0.8% CV
• 1.5-2.5 mmol/L: 0.5% CV |
  | Linearity | Demonstrate linearity over the specified reportable range with a good fit. | Linearity demonstrated over 0.25 - 2.50 mmol/L reportable range. Regression: Slope 0.9738, Intercept 0.360, R2 0.999. "Absolute degree of nonlinearity results met the acceptance criteria." |
  | Limit of Quantitation (LoQ) | LoQ should be at or below the lower limit of the reportable range. | LoQ determined to be 0.21 mmol/L, which is below the lower limit of the reportable range (0.25 mmol/L). |
  | Limit of Blank (LoB) | LoB should be very low, indicating minimal signal in the absence of analyte. | LoB determined to be 0.14 mmol/L. |
  | Limit of Detection (LoD) | LoD should be very low, indicating the lowest detectable concentration. | LoD determined to be 0.15 mmol/L. |
  | Interference | No significant interference from common substances or specified interfering substances below allowed error (Ea). | Several substances tested; Interference identified for: Leflunomide, Lithium Lactate, Lithium Thiocyanate, Sodium Thiosulfate, Teriflunomide. For these, details on the specific effect (e.g., "Decreased results ≥ 0.4 mmol/L") are provided. Other substances showed no interference at tested concentrations. |
  | Method Comparison with Predicate Device | Strong correlation (r value close to 1) and a slope close to 1 with an intercept close to 0 when compared to the predicate device. | iCa: N=250, Slope 1.00, Intercept -0.02, r 0.99. |

Study Details:

1. A table of acceptance criteria and the reported device performance: See table above.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective):

   • Precision (Aqueous): 80-81 measurements per level (N values in Table 1). Data provenance is not specified regarding country, but it was conducted "at one site." The study design (20-day multi-day precision testing) implies a prospective collection of data for this specific study.
   • Precision (Whole Blood): 241 samples (132 venous, 109 arterial). Data collected across "three point of care sites." Data provenance regarding country or retrospective/prospective nature is not explicitly mentioned, but the context of a validation study typically implies prospective collection for this analysis.
   • Linearity: Not explicitly stated but implies multiple whole blood samples across the range (0.22 - 2.81 mmol/L).
   • LoQ/LoB/LoD: Not explicitly stated how many individual sample measurements were involved, but mentions "whole blood that was altered" and conducted over "four (4) days using two (2) cartridge lots."
   • Interference: Not explicitly stated, but each substance was evaluated by comparing a control sample to a spiked sample.
   • Method Comparison: 250 samples (N value in Table 6). Venous and arterial blood specimens were evaluated. Data provenance regarding country or retrospective/prospective nature is not explicitly mentioned.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience):

   • Not applicable for this type of device. This is an in vitro diagnostic (IVD) device for quantitative measurement. Ground truth is established by reference methods or direct measurement comparisons, not expert subjective interpretation (like radiologists for imaging). The predicate device (Epocal EPOC Blood Analysis System) served as the comparative method for the method comparison study.

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

   • Not applicable. As an IVD device measuring a quantitative analyte, there is no subjective interpretation requiring adjudication methods.

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 is not an AI-assisted diagnostic imaging device that involves human reader interpretation. It's an automated quantitative IVD system.

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

   • Yes, this is a standalone device. The performance characteristics (precision, linearity, LoQ, LoD, LoB, interference) and the method comparison against a predicate device evaluate the device itself without direct human interpretation influencing the measurement result for iCa. The system automatically performs quality checks and suppresses results if specifications are not met.

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

   • For precision studies, the 'ground truth' is the mean value derived from repeated measurements of stable materials or samples, reflecting the inherent variability.
   • For linearity studies, ground truth is established by accurately prepared samples with known concentrations.
   • For LoQ/LoB/LoD studies, ground truth is based on samples expertly prepared to very low or zero analyte concentrations.
   • For interference studies, ground truth is the expected value of the sample without the interfering substance.
   • For method comparison, the predicate device (Epocal EPOC Blood Analysis System) serves as the "ground truth" or reference for comparison.

8. The sample size for the training set:

   • Not applicable. This document describes a traditional IVD device validation, not a machine learning or AI model development that requires a "training set" in the conventional sense of AI. The device's underlying technology relies on ion-selective electrodes, not a learned model from a large dataset.

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

   • Not applicable. See point 8.

Regulation Number and Section

§ 862.1145 Calcium test system.

(a)
Identification. A calcium test system is a device intended to measure the total calcium level in 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).(b)
Classification. Class II.