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.

Device Description

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.

AI/ML Overview

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.

Acceptance Criterion (Implicit)	Reported Device Performance
Precision Performance (Substantially equivalent to predicates per NCCLS EP5-A)	"Precision performance data indicate that the performance of the Stat K In Vitro Diagnostic Test System is substantially equivalent to both the Corning 614 and the Beckman Coulter SYNCRON CX5 PRO System." (No specific numerical range or CV% provided in this summary, but the conclusion of substantial equivalence implies meeting acceptable precision limits).
Method Comparison to Corning 614 (Substantially equivalent to predicate per NCCLS EP9-A2)	Linear Regression: Stat K = 0.12 + 0.97 Corning 614
Method Comparison to Beckman Coulter SYNCRON CX5 PRO (Substantially equivalent to predicate per NCCLS EP9-A2)	Linear Regression: Stat K = 0.08 + 1.02 Beckman CX5

Study Details:

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).
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.
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.
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.
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.
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.
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."
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.

Summary

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K042270

ATTACHMENT II. 510(k) SUMMARY [As required by 21 CFR 807.87(h)]

Introduction

According to the requirements of 21 CFR §807.92, the following information provides sufficient detail to understand the basis for a determination of substantial equivalence.

Identification of Submitter [21 CFR §807.92(a)(1)]

Submitter:	Martin J. Patko
	Vice President of Research and
	Development
	StatChem, Inc.
	619 North Poplar St.
	Orange, CA 92868
Telephone No:	(714) 634-8456
Fax No:	(714) 634-8615
E-Mail:	mpatko@att.net
Date of preparation:	August 20, 2004

Identification of the Device [21 CFR §807.92(a)(2)]

Device Proprietary Name: Common Name: Classification Name:

Stat K In Vitro Diagnostic Test System Potassium Test System In Vitro Diagnostic Potassium Test System (per 21 CFR 862.1600)

Marketed Devices to Which Equivalence is Claimed [21 CFR §807.92(a)(3)]

Device: Manufacturer: 510(k) Number:

Device: Manufacturer: 510(k) Number: Stat K System Portable Diagnostic Services, Inc. K915345

SYNCHRON CX5@ SYSTEM Beckman Coulter, Inc. K011465

Corning 614 Na/K Analyzer Corning Medical & Scientific K843530

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ATTACHMENT II. 510(k) SUMMARY (Continued) [As required by 21 CFR 807.87(h)]

Description of Device [21 CFR §807.92(a)(4)]

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.

Intended Use [21 CFR §807.92(a){5)]

The StatChem Stat K is a device intended to measure potassium in venous whole blood. Measurements obtained 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.

The intended use statement for the Stat K In Vitro Diagnostic Test System differs from the indended use statement from that of the legally marketed predicate devices in that the Stat K In Vitro Diagnostic Test System measures potassium levels in venous whole blood. Thus, new issues of safety and effectiveness of Stat K In Vitro Diagnostic Test System are not introduced.

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ATTACHMENT II. 510(k) SUMMARY (continued) [As required by 21 CFR 807.87(h)]

Summary of Technological Characteristics in Comparison to the Predicate Devices [21 CFR §807.92(a)(6)]

The Stat K In Vitro Diagnostic Test System employs nearly identical technological characteristics as the Portable Diagnostic Services Stat K predicate device. A comparison of the similarities and differences of the Stat K In Vitro Diagnostic Test System with that of the predicate devices are provided in Table 1, below.

TABLE 1. SIMILARITIES AND DIFFERENCES
DEVICE	PORTABLEDIAGNOSTICSSTAT K	STATCHEMSTAT K	BECKMANCOULTERCX5 PRO	CORNING 614NA/KANALYZER
Intended Use	PotassiumMeasurement	PotassiumMeasurement	Multiple	Multiple
MeasurementPrinciple	Electrochemical	Electrochemical	Electrochemical	Electrochemical
MeasuringRange	2.0 - 8.0 mEq/L	3.00 - 7.00 mEq/L2.00 - 8.00	3.6 - 5.0 mEq/L	0.50 - 9.99mEq/L
Specimen Type	Whole Blood,Serum orPlasma	Venous WholeBlood	Serum, Plasma orUrine	Whole Blood,Serum, or Urine
Analyzer Features:
Power Source	Battery Operated	Battery Operated	AlternatingCurrent	AlternatingCurrent
Hand held	Yes	Yes	No	No
Batter operated	Yes	Yes	No	No
Display	Liquid Crystal	Liquid Crystal	Liquid Crystal	VacuumFluorescentDisplay
Analyzer/CartridgeInterface	Bar Code	SemiconductorElement	Does not apply	Does not apply
TemperatureCompensated	Yes	Yes	Yes	Yes
System Control	Microprocessor	Microprocessor	Microprocessor	Microprocessor
Cartridge Features:
SensingMembrane	Gel based	Plastic Polymer	Solvent based	Solvent based
CalibrationMembrane	Gel based	Gel based	None	None
Single Use	Yes	Yes	Batch	Batch
Shelf Life	18 Months	18 Months	Not Applicable	Not applicable

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ATTACHMENT II. 510(k) SUMMARY (continued) [As required by 21 CFR 807.87(h)]

Summary of Non-Clinical Tests Submitted [21 CFR §807.92(b)(1)]

Stat K In Vitro Diagnostic Test System measurements are performed on venous whole blood specimens and have been calibrated to agree with standard laboratory and reference methods. The Stat K In Vitro Diagnostic Test System uses undiluted electrochemical methods which may differ from those obtained by indirect or diluted methods (N.W. Tiez, E.L. Pruden, O. Siggaard-Anderson, "Electrolytes" In Tiez Textbook of Clinical Chemistry - Second Edition, C.A. Burtis and E.R. Ashwood, eds. Philadelphia; W.B. Saunders Company, 1994). Moreover, the user is cautioned to perform Potassium testing with the Stat K In Vitro Diagnostic Test System using free flowing venous blood only.

The equivalence of the Stat K In Vitro Diagnostic Test System to both the Corning 614 and the Beckman Coulter SYNCRON CX5 PRO System was established on the basis of pre-clinical testing. Testing was 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. Precision performance experiments were based on NCCLS EP5-A, Evaluation of Precision Performance of Clinical Chemistry Devices; Approved Guideline. Method comparison experiments were based on an experimental design modeled after NCCLS EP9-A2, Method Comparison and Bias Estimation Using Patient Samples: Approved Guideline - Second Edition.

Precision performance was characterized using both aqueous solutions of known potassium concentrations and venous whole blood samples. Precision performance data indicate that the performance of the Stat K In Vitro Diagnostic Test System is substantially equivalent to both the Corning 614 and the Beckman Coulter SYNCRON CX5 PRO System.

Method comparison experiments were conducted comparing the Stat K In Vitro Diagnostic Test System to the both the Corning 614 Na/K Analyzer and the Beckman Coulter SYNCRON CX5 PRO System. The resulting linear regression line comparing the Stat K In Vitro Diagnostic Test System to the Corning 614 is: Stat K = 0.12 + 0.97 Corning 614. The resulting linear regression line comparing the Stat K In Vitro Diagnostic Test System to the Beckman Coulter SYNCRON CX5 PRO System is: Stat K = 0.08 + 1.02 Beckman CX5. Method comparison data indicate that the performance of the Stat K In Vitro Diagnostic Test System is substantially equivalent both the Corning 614 and the Beckman Coulter SYNCRON CX5 PRO System.

In summary, the Stat K In Vitro Diagnostic Test System is substantially equivalent to the three predicate devices.

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ATTACHMENT II. 510(k) SUMMARY (continued) [As required by 21 CFR 807.87(h)]

Interfering Substances

In vitro diagnostic tests of all types are potentially perturbed by the interference of certain endogenous substances and drugs found in the blood of individuals being tested. During the evaluation of the predicate device, Portable Diagnostic Services' Stat K System, such phenomena were rigorously studied for important endogenous substances and drugs encountered (see FDA 510(k) number K915345). Ion selective electrodes, because of very high analyte selectivity, are generally resistant to such interference (N.W. Tiez, E.L. Pruden, O. Siggaard-Anderson, "Electrolytes" In Tiez Textbook of Clinical Chemistry -- Second Edition, C.A. Burtis and E.R. Ashwood, eds. Philadelphia: W.B. Saunders Company, 1994), as was the Portable Diagnostic Services' Stat K System predicate device, and thus Stat K In Vitro Diagnostic Test System.

Conclusions Drawn from Non-Clinical Tests Submitted [21 CFR §807.92(b)(3)]

Non-clinical tests performed by medical professionals under conditions expected to simulate actual use conditions using the Stat K In Vitro Diagnostic Test System support a claim of substantial equivalence to the predicate devices.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/5/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three stripes forming its body and wings. The eagle is positioned within a circle, and the text "DEPARTMENT OF HEALTH & HUMAN SERVICES U.S.A." is arranged around the upper half of the circle.

Public Health Service

001 6 - 2004

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Mr. Martin J. Patko Vice President of Research and Development StatChem, Inc. 619 North Poplar Street Orange, CA 92868

K042270 Re:

Ro42270
Trade/Device Name: Stat K In Vitro Diagnostic Test System Regulation Number: 21 CFR 862.1600 Regulation Name: Potassium Regulatory Class: Class II Product Code: CEM Dated: August 20, 2004 Received: August 23, 2004

Dear Mr. Patko:

We have reviewed your Section 510(k) premarket notification of intent to market the device we nave reviewed your becamed the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate 10 use stated in the encrobars) to trgains and ment date of the Medical Device Amendments, or to conninered prior to rial 2011-17-11, in accordance with the provisions of the Federal Food, Drug, ucvices that have been resuire approval of a premarket approval application (PMA). and Costietle Act (110) that as novice, subject to the general controls provisions of the Act. The I ou may, merelore, mainer of the Act include requirements for annual registration, listing of general oonlines profitering practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it your device is classified (dis additional controls. Existing major regulations affecting your device it may be subject to bach abon and Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean i lease oc actifical that I Dris issual.re or our device complies with other requirements of the Act that I Dri has made a availations administered by other Federal agencies. You must or any it cach statutes and registments, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice er it it it oo if, tabeling systems (QS) regulation (21 CFR Part 820).

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Page 2

This letter will allow you to begin marketing your device as described in your Section 510(k) I ma letter with and hyper finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific information about the application of labeling requirements to your device, or guestions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 594-3084. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.

Sincerely yours,

Jean M. Cooper, U.S., DVM.

Jean M. Cooper, MS, D.V.M. Director Division of Chemistry and Toxicology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): K042270

Device Name: Stat K In Vitro Diagnostic Test System

Indications For Use:

The StatChem Stat K is a device intended to measure potassium in anticoagulated venous whole blood The Stationell Stat K is a device interiod to modelly produced by this device are used to and assayed within twenty mindice or ochent of disease conditions characterized by low or montor clectroryte bullanoo in the clagneed by a central laboratory or at point of care sites.

Prescription Use X (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

Alberto C
Division Sign-Off

Office of In Vitro Diagnos Device Evaluation an

510(k) K042270

Page 1 of 1

Regulation Number and Section

§ 862.1600 Potassium test system.

(a)
Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte balance in the diagnosis and treatment of diseases conditions characterized by low or high blood potassium levels.(b)
Classification. Class II.