Search Results

The StatChem Stat K is a device intended to measure potassium in anticoagulated venous whole blood. Measurements produced by this device are used to monitor electrolyte balance in the diagnosis and treatment of disease conditions characterized by low or high blood potassium levels. The Stat K may be used for adult or pediatric venous whole blood samples. It may be used by a central laboratory or at point of care sites.

Stat K In Vitro Diagnostic Test System is a medical device used for the in vitro diagnostic measurement of Potassium in venous whole blood. The device consists of a battery operated hand-held Analyzer and a precalibrated and disposable Sensor cartridge. While basically a standard electrochemical device that employs a sensing membrane embedded with the potassium selected ligand Valinomycin, Stat K differs from other similar devices in several important ways. The Sensor cartridge is liquid-free allowing storage at room temperature for several months without degradation of performance. The Sensor cartridge is precalibrated at the factory thus requiring no operator interaction to perform calibration. The Sensor cartridge is designed for single use only. This device is exceptionally simple to use as the operator is required to perform four elementary steps to complete the test; (1) Insert Sensor Cartridge, (2) Peel Sensor cap when prompted, (3) Apply blood sample when prompted, and, (4) Read results on LCD display. The Stat K Potassium Sensor uses an ion selective membrane to determine the concentration of potassium ions in solution. The physical structure of the potassium selective Valinomycin membrane is such that the complexing sites on the membrane selectively bind to the Potassium ion. When complexing occurs, an electrical potential is generated proportional to the logarithm of the potassium ion concentration in the sample. The concentration of Potassium ion is calculated from the electrode potential by use of the Nernst Equation. Calibration of the Stat K In Vitro Diagnostic Test System is automatically performed immediately prior to each potassium determination. Each Potassium Sensor contains a calibration material with a predetermined concentration of Potassium.

Here's a summary of the acceptance criteria and the study details for the Stat K In Vitro Diagnostic Test System, based on the provided 510(k) summary:

Acceptance Criteria and Reported Device Performance

The acceptance criteria for the Stat K In Vitro Diagnostic Test System are implicitly established by demonstrating substantial equivalence to predicate devices (Corning 614 Na/K Analyzer and Beckman Coulter SYNCHRON CX5 PRO System) through precision and method comparison studies. The performance is reported in terms of linear regression equations comparing the device to these predicates.

Study Details:

1. Sample size used for the test set and the data provenance:

   • Test Set Sample Size: Not explicitly stated in the provided text for the precision or method comparison studies. The text mentions "patient samples" for method comparison, but not the specific number.
   • Data Provenance: The studies were performed "in the hands of intended users at various point-of-care facilities and at the laboratory facility of StatChem Inc., located in Orange, California." This suggests a mix of prospective (point-of-care) and possibly retrospective (laboratory facility) testing with real-world samples. The data is from the USA (Orange, CA).

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

   • The ground truth for the method comparison studies was established by measurements from the predicate devices (Corning 614 Na/K Analyzer and Beckman Coulter SYNCHRON CX5 PRO System), which are presumably standard laboratory instruments. The summary does not mention individual "experts" establishing ground truth in the sense of clinical reviewers; rather, it's based on established reference methods.

3. Adjudication method for the test set:

   • Not applicable as the ground truth was based on comparator devices/reference methods rather than expert consensus requiring adjudication.

4. 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:

   • No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This device is an in-vitro diagnostic test system, an automated analyzer, not an AI-assisted diagnostic imaging or interpretation tool that would typically involve human "readers" or AI assistance to humans.

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

   • Yes, the performance presented (precision, method comparison) reflects the standalone performance of the Stat K In Vitro Diagnostic Test System. Although the testing was "in the hands of intended users," the reported results are from the device's measurements, not human interpretation aided by the device.

6. The type of ground truth used:

   • Reference Method / Comparator Device: The ground truth for the method comparison studies was established by the measurements from the legally marketed predicate devices: the Corning 614 Na/K Analyzer and the Beckman Coulter SYNCHRON CX5 PRO System. For precision, it was based on "aqueous solutions of known potassium concentrations and venous whole blood samples," suggesting traceable reference materials and standard laboratory practice.

7. The sample size for the training set:

   • The document does not specify a "training set" in the context of an algorithm or machine learning device. For this type of in-vitro diagnostic device, development and calibration would involve internal studies, but these are not typically referred to as a "training set" in the same way as AI/ML. The device is "precalibrated at the factory."

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

   • Not applicable as there is no mention of a "training set" in the context of machine learning. The device's calibration and internal performance would be established through a process of using known standards and calibrators, as mentioned for the "precalibrated" sensor cartridge and the "calibration material with a predetermined concentration of Potassium" contained within each sensor.

Ask a specific question about this device