Search Results
Found 1 results
510(k) Data Aggregation
(99 days)
I-STAT PROTHROMBIN TIME TEST
The i-STAT PT is a prothrombin time test cartridge and is an in vitro diagnostic test intended for quantitative prothrombin time testing for the monitoring of oral anticoagulation therapy using fresh venous or capillary whole blood samples. The i-STAT PT test is not intended for evaluating individual factor deficiencies. The cartridge is to be used with the i-STAT Portable Clinical Analyzer with thermal control (Models 200 and 300), but will not run on the Philips Medical Systems (formerly Agilent Technologies) Blood Analysis Module (BAM). As part of the i-STAT System, the PT test is to be used by trained and certified health care professionals in accordance with a facility's policies and procedures.
The i-STAT PT, a prothrombin time test, is useful for monitoring patients receiving oral anticoagulation therapy such as Coumadin or warfarin.
The i-STAT PT test is contained in a single test cartridge. In use, approximately 40 microliters of fresh whole blood are placed in the cartridge as described below. The cartridge is inserted into the thermally controlled i-STAT Portable Clinical Analytical steps are performed automatically. Patient and user information may be entered into the analyzer via a keypad during the automated analysis cycle.
In the i-STAT PT test the endpoint is indicated by the appearance of an electroactive marker generated by the thrombin-mediated conversion of a synthetic substrate included in the reagent. Detection of the marker indicates generation of thrombin and therefore complete activation of the coagulation cascade. The result is reported as an International Normalized Ratio (INR) and, optionally, in seconds. The optionally displayed seconds is intended to reflect a typical plasma prothrombin time.
The PT test cartridge is assembled from plastic components that provide the conduits for fluid handling r no r r toot our negor chips. The coagulation test is identified to the user through the name and color code on the cartridge label and by the analyzer through features integral to the cartridge.
During the test the blood sample is mixed with reagents which are coated on the cartridge cover in a segment of the sensor channel. The reagent layer includes tissue thromboplastin as an activating agent, the thrombin substrate, a heparin-neutralizing enzyme, and inert matrix components. These reagents allow activation of the coagulation cascade and detection of clot formation.
Whole blood is introduced into the sample well of the cartridge at the sample port and the cartridge is closed and inserted into the analyzer. Insertion of the cartridge initiates a controlled and monitored sequence of steps in the instrument. These are:
- Electrical contact is made between the analyzer electronic input circuits and the cartridge. . The analyzer identifies the type of cartridge being used and the tests contained in the cartridge.
- The dry chips and sensor channel are heated to 37°C. .
- The blood is then moved forward. Feedback from the fluid position sensor is used to allow . controlled oscillation of the blood segment resulting in dissolution of the reagent layer.
- During the course of testing, the position of the blood segment is actively controlled to . maintain the length of the blood containing the reagent coincident with the endpoint detector.
- Calculation of the sample clot time is performed and displayed. .
The provided text describes the i-STAT PT Test, a prothrombin time test cartridge for monitoring oral anticoagulation therapy. The acceptance criteria and supporting studies are detailed in the "Summary of Non-Clinical Performance in Support of Substantial Equivalence" and "Summary of Clinical Test Performance is Support of Substantial Equivalence Claims" sections.
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state "acceptance criteria" in a quantitative, pass/fail manner. Instead, it demonstrates performance in various conditions and compares it to a predicate device, the Coaguchek™ S System. The implicit acceptance criteria appear to be the demonstrated insensitivity to certain factors and comparable performance to the predicate device within reasonable clinical limits.
| Implicit Acceptance Criteria (Demonstrated Performance) | Reported Device Performance (i-STAT PT Test) | Predicate Device Performance (Coaguchek™ S System) (where available) |
|---|---|---|
| Insensitivity to heparin | Insensitive up to 1.0 U/mL | Sensitive to levels over 0.15 U/mL |
| Insensitivity to fibrinogen (manipulated samples) | Insensitive to levels as low as 70 mg/dL | Not explicitly stated for specific levels, but endpoint detection relies on fibrinogen conversion. |
| Insensitivity to fibrinogen (clinical samples) | Insensitive between 142 and 528 mg/dL | Not explicitly stated. |
| Insensitivity to hematocrit | Hematocrits in the range of 24-52% do not significantly affect results | Not explicitly stated. |
| Sensitivity to warfarin-impacted factors | Sensitive to all factors impacted by warfarin therapy | Implied by its intended use for anticoagulation monitoring. |
| Within-sample reproducibility | 5.4% (from duplicate sample testing in method comparison) | 5.9-9.8% in whole blood samples in therapeutic range |
| Imprecision (Plasma Controls, Level 1) | %CV 4.5 at INR 1.1 | Not explicitly stated. |
| Imprecision (Plasma Controls, Level 2) | %CV 6.9% at INR 2.5 | Not explicitly stated. |
| Total imprecision (whole blood controls) | Not explicitly stated, but plasma control data is given. | 10.2% at INR 1.5, 15.1% at INR 3.7 |
| Correlation with laboratory plasma instruments (Dade Innovin reagent) | Correlation coefficients of 0.898, 0.943, 0.948 across three sites | Comparison is against a lab method, not the predicate directly for this statistic. |
| Correlation between i-STAT capillary and venous samples | Correlation coefficient of 0.962 | Not applicable, as this is an internal comparison for the i-STAT device. |
2. Sample size used for the test set and the data provenance:
- Method Comparison Study (i-STAT PT vs. Dade Innovin lab instrument):
- Sample Sizes: N = 183 (Site 1), N = 180 (Site 2), N = 177 (Site 3). Total = 540 patient samples.
- Data Provenance: The samples were from "patients undergoing routine monitoring of oral anticoagulation therapy." This implies prospective clinical data collected at "three external sites." The country of origin is not explicitly stated but is implicitly the USA given the FDA submission.
- Capillary vs. Venous Sample Comparison Study:
- Sample Size: N = 59.
- Data Provenance: From "patients undergoing routine monitoring of oral anticoagulation therapy." This implies prospective clinical data from one site. The country of origin is not explicitly stated.
- Other non-clinical studies: The sample sizes for heparin-spiked, manipulated fibrinogen, and manipulated hematocrit samples are not specified, only that "studies established" these characteristics. These are likely laboratory-controlled, prospective studies.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The ground truth for the clinical method comparison study was established by "laboratory plasma instruments using Dade Innovin reagent (x)". The document does not specify the number of experts or their qualifications for performing these reference laboratory tests. It's assumed to be standard clinical laboratory practice.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
No adjudication method is described. The comparison is directly between the i-STAT device and a reference laboratory method (Dade Innovin reagent) for patient samples, and between i-STAT capillary and venous samples.
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:
This is not an AI-assisted diagnostic device for human readers. It's an in vitro diagnostic (IVD) device. Therefore, an MRMC comparative effectiveness study involving human readers with/without AI assistance is not applicable and was not performed or described.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
The i-STAT PT test is a standalone device that automatically performs the test and reports results (INR and seconds). The analysis steps are "performed automatically." While "trained and certified health care professionals" use the device, their role is operational (sample collection, cartridge insertion, data entry), not interpretive in the sense of a diagnostic image or signal. The clinical studies described represent standalone performance of the device compared to a reference method.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The primary ground truth for the device's performance claims against routine laboratory testing is comparison to a recognized laboratory reference method (Dade Innovin reagent on plasma instruments). For other claims (heparin, fibrinogen, hematocrit sensitivity), the ground truth was established through manipulated samples and clinical patient studies where the actual levels of these components could be measured and correlated with i-STAT results.
8. The sample size for the training set:
The document describes studies for validation and performance comparison for regulatory submission. It does not explicitly mention a separate "training set" for an algorithm. This suggests that if any internal algorithm development or calibration occurred, the data used for that is not disclosed here as a distinct training set. The clinical and non-clinical data presented are for demonstrating performance and substantial equivalence.
9. How the ground truth for the training set was established:
As no explicit "training set" is described for an algorithm, the method for establishing its ground truth is not applicable based on the provided text.
Ask a specific question about this device
Page 1 of 1