The pHoenix ISE Reagents for Beckman CX Systems are intended for use as ISE Reagents for the determination of Na , K , C1 and C02 in human serum samples on the Beckman CX Systems.

The Electrolyte Buffer is diluted with the Wash Solution and introduced into the serum samples for the quantitative determination of Na+, K+, Cl- and C02.

The Electrolyte Reference Reagent is to provide reference points for Na+, K+, C1- and C02.

The C02 Acid Reagent is to release C02 from serum samples.

The C02 Alkaline Buffer is to provide a constant C02 concentration as reference for the C02 electrode. The Wash Concentrate is intended to be diluted with de-ionized water. The working Wash Solution is used to wash the systems sample probe and to dilute reagents on Beckman CX Systems.

The Calibrators are used for the calibration of the CX ISE Modules for the quantitative determination of Na+, K+ Cl+and C02 in serum samples.

Device Description

pHoenix Diagnostics, Inc. is submitting a 510 (k) notification for the following: (1) Electrolyte Buffer, (2) Electrolyte Reference Reagent and (3) C02 Acid Reagent, (4) C02 Alkaline Buffer, (5) Wash Concentrate and (6) ISE Calibrator Level 1,2 and 3. These ISE Reagents are intended for use on the ISE Module of the Beckman CX Systems for the quantitative determination of Na+, K+, C1- and C02 in human serum.

The Electrolyte Buffer is intended to provide constant ionic strength for measuring electrolytes in human serum samples. The Electrolyte Buffer is combined with the Wash Solution and introduced into the serum samples for the quantitative determination of Na+, K+, C1- and C02. The Electrolyte Reference Reagent is to provide reference points for Na+, K+, C1- and C02. The C02 Acid Reagent is to release C02 from serum samples, The C02 Alkaline Reagent is to provide a constant C02 concentration as reference for the C02 electrode. The Wash Concentrate is intended to be diluted with de-ionized water. The working Wash Solution is used to wash the systems sample probe and to dilute reagents on Beckman CX Systems. The Calibrators are used for the calibration of the CX ISE Modules.

AI/ML Overview

1. Table of Acceptance Criteria and Reported Device Performance

The device is a set of reagents for an In Vitro Diagnostic (IVD) system. Performance is primarily evaluated through precision and correlation studies against a predicate device.

Analyte	Acceptance Criteria (Implicit from Predicate Comparison)	Reported Device Performance (Precision - CV%) Level 2	Reported Device Performance (Precision - CV%) Level 1	Reported Device Performance (Correlation - R)
Na+	Should be comparable to Beckman Coulter Reagents	1.2% (Total), 0.55% (Run to Run)	1.57% (Total), 0.65% (Run to Run)	0.999
K+	Should be comparable to Beckman Coulter Reagents	5.42% (Total), 2.00% (Run to Run)	0.96% (Total), 0.44% (Run to Run)	0.998
Cl-	Should be comparable to Beckman Coulter Reagents	2.01% (Total), 1.23% (Run to Run)	0.56% (Total), 0.32% (Run to Run)	0.996
CO2	Should be comparable to Beckman Coulter Reagents	5.8% (Total), 3.57% (Run to Run)	5.48% (Total), 3.76% (Run to Run)	0.985

Note: The document does not explicitly state acceptance criteria in numerical terms. The "acceptance criteria" presented above are inferred from the stated goal of demonstrating "performance equivalence" to the predicate devices and the robust correlation coefficients and low CV% values typically expected for IVD assays.

2. Sample Size Used for the Test Set and Data Provenance

Precision Study:
- Sample Size: For each analyte (Na+, K+, Cl-, CO2), two levels of serum controls were measured. Each level had 80 total measurements (2 runs per day, 2 times per run for 20 days).
- Data Provenance: The document states "Typical Results are as follows," suggesting the data was generated specifically for this submission. The origin of the serum controls (e.g., country) is not specified. It is a prospective study as the testing was conducted using the pHoenix reagents on Beckman CX Systems.
Correlation Study:
- Sample Size: 50 samples were used for each analyte (Na+, K+, Cl-, CO2).
- Data Provenance: The samples included "patient serum samples, control samples and spiked samples." The country of origin is not specified. This is a prospective study as the measurements were taken using pHoenix reagents and compared to measurements with Beckman Coulter reagents on the same analyzer.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

Not applicable. This device is an IVD reagent set, and the "ground truth" for performance studies (precision and correlation) is based on quantitative measurements generated by laboratory instruments, not expert interpretation. The comparison is made against a legally marketed predicate device (Beckman Coulter reagents).

4. Adjudication Method for the Test Set

Not applicable. As noted above, performance is based on quantitative laboratory measurements, not subjective interpretation requiring adjudication among experts.

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 an IVD reagent set, not an AI-powered diagnostic imaging or interpretation tool. The study focuses on the analytical performance of the reagents.

6. If a Standalone (i.e. algorithm only, without human-in-the-loop performance) Was Done

Not applicable. This device is an IVD chemical reagent set. Its performance inherently involves an instrument (Beckman CX Systems) and a human operator to perform the tests, although the performance data collected (precision and correlation) represents the analytical performance of the reagents themselves.

7. The Type of Ground Truth Used

For the precision study, the ground truth is the quantitative measurement obtained over multiple runs, and the benchmark is the expected variability for such assays (as indicated by NCCLS Guideline EP5-T). For the correlation study, the "ground truth" for comparison is the results obtained using the legally marketed predicate Beckman Coulter reagents. This is a comparative study against an established method.

8. The Sample Size for the Training Set

Not applicable. This document describes the validation of an IVD reagent set, not a machine learning model. There is no concept of a "training set" in this context. The reagents themselves are "trained" through their manufacturing process to consistently produce accurate results.

9. How the Ground Truth for the Training Set Was Established

Not applicable. (See #8).

Summary

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JC020364

510 (k) Summary

pHoenix ISE Reagents for Beckman CX Systems

Beckman Instruments was the original manufacturer of the Beckman CX Systems. Recently Beckman Instruments acquired Coulter and these Chemistry Systems continued to be referred to as Beckman CX Systems. Beckman Coulter is the name of the new company.

pHoenix Diagnostics, Inc. is claiming substantial equivalence to predicate devices manufactured by Beckman Coulter, the original manufacturer of these reagents and Beckman CX Systems.

The products encompassed by this 510 (k) submission are Class I and Class II In Vitro Diagnostic Solutions manufactured by pHoenix Diagnostics, Inc., 8 Tech Circle, Natick, MA 01760. These pHoenix ISE Reagents are intended to serve as direct replacements to like named products manufactured by Beckman Coulter.

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510 (k) Summary cont.

pHoenixCat.#	BeckmanCat. #	Description	Models	Class
47-2095	472095	Electrolyte Buffer	All CX Systems	1
45-0214	450214	Electrolyte Reference Reagent	All CX Systems	2
44-3320	443320	C02 Alkaline Buffer	All CX Systems	1
44-3330	443330	C02 Acid Reagent	All CX Systems	1
44-3335	443335	Wash Concentrate	All CX Systems	1
46-5908	465908	ISE Calibrator Level 1	All CX Systems	2
46-5909	465909	ISE Calibrator Level 2	All CX Systems	2
46-5910	465910	ISE Calibrator Level 3	All CX Systems	2

Listed below are pHoenix products and their Beckman Coulter equivalents.

pHoenix uses a similar composition, description and packaging design as that used by Beckman Coulter in its products. pHoenix has shown performance equivalence of its products to Beckman instrument products in the following manner:

. Through a method comparison where results obtained on Beckman CX Clinical Chemistry Systems calibrated with pHoenix products and compared with results obtained on the same analyzer calibrated with Beckman CX Systems products; and
. Through a precision study where pHoenix products were installed on Beckman CX Systems Clinical Chemistry Systems and samples were measured one run per day for a 20 day period.

A summary of the results of these studies follows:

Precision data was collected from the analysis of 2 levels of serum controls measured 2 runs per day, 2 times per run for 20 days on Beckman CX Systems for Na , K , Cl and C02 installed with pHoenix reagents. The NCCLS Guideline for precision evaluation, EP5-T, was followed. Typical Results are as follows: Level 2

Analyte		N	Mean	STD	CV%	Min	Max
Na+	Total	80	121	1.47	1.2	120	124
	Run to Run	20	121	0.67	0.55	120	123
K+	Total	80	1.93	0.104	5.42	1.8	2.1
	Run to Run	20	1.93	0.040	2.00	1.85	2.0
Cl-	Total	80	70.6	1.42	2.01	68	73
	Run to Run	20	70.6	0.87	1.23	69	72
C02	Total	80	16.25	0.94	5.8	14.1	17.2
	Run to Run	20	16.25	0.57	3.57	14.7	17.2

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510 (k) Summary cont.

1T0110پﺮCIL	1t
-------------------------------------	--------

Analyte		N	Mean	STD	CV%	Min	Max
Na+	Total	80	164.2	2.58	1.57	160	169
	Run to Run	20	164.2	1.07	0.65	162	166
K+	Total	80	6.50	.062	0.96	6.4	6.6
	Run to Run	20	6.50	.028	0.44	6.4	6.5
Cl-	Total	80	147.5	0.824	0.56	146	149
	Run to Run	20	147.5	.473	.32	147	148
C02	Total	80	34.1	1.87	5.48	30	39
	Run to Run	20	34.1	1.28	3.76	32	37

Correlation with Beckman Coulter Reagents

Correlation data was collected from 50 samples (patient serum samples, control samples and spiked samples) for Na , K , CI and C02 measured on Beckman CX Systems installed with pHoenix reagents (Electrolyte Buffer, Electrolyte Reference Reagent, C02 Alkaline Buffer, C02 Acid Reagent, Wash Cincentrate, and Calibrators) as compared with Beckman Coulter reagents separately. A Linear Regression Analysis was performed using Beckman data as the independent X Variable and pHoenix Diagnostics Data as the Dependent Y Variable in the equation Y = a + bX. Typical results are as follows:

Analyte	N	Slope	Intercept	CorrelationCoefficient	Range
Na+	50	1.027	0.60	0.999	100 - 200
K+	50	1.04	0.348	0.998	1 - 15
Cl-	50	0.977	7.17	0.996	50 - 200
C02	50	0.964	1,058	0.985	5 - 40

I hope you find this information useful and informative.

Ram Nunna, President

2/1/02

Date

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the seal of the Department of Health & Human Services USA. The seal features a stylized eagle with three lines representing its body and wings. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" are arranged in a circular pattern around the eagle.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

JUN 0 4 2002

Mr. Ram Nunna President pHoenix Diagnostics, Inc. 8 Tech Circle Natick, MA 01760

Re: K020364

Trade/Device Name: pHoenix ISE Reagents for Beckman CX Systems 700/900 series Regulation Number: 21 CFR 862.1665; 21 CFR 862.1600; 21 CFR 862.1170; 21 CFR 862.1120; 21 CFR 862.1150 Regulation Name: Sodium test system; Potassium test system; Chloride test system; Blood gases (Poo2, Po2) and blood pH test system; Calibrator Regulatory Class: Class II Product Code: JGS: CEM; CGZ, CHL, JIX Dated: April 2, 2002 Received: April 8, 2002

Dear Mr. Nunna:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing 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 may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. 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 that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 -

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA 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 advice for your device on our labeling regulation (21 CFR Part 801 and ' additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled. "Misbranding by reference to premarket notification" (21CFR 807,97). Other general information on your responsibilities under the Act may be obtained 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/cdrb/dsma/dsmamain.html".

Sincerely yours.

Steven Butman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory-Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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INDICATIONS FOR USE STATEMENT

510(k) Number (if known): K0 Z036

Device Name: pHoenix ISE Reagents for Beckman CX Systems 700/900 series

Indications For Use:

Intended Use:

The pHoenix ISE Reagents for Beckman CX Systems are intended for use as ISE Reagents for the determination of Na , K , C1 and C02 in human serum samples on the Beckman CX Systems.

The Electrolyte Buffer is diluted with the Wash Solution and introduced into the serum samples for the quantitative determination of Na+, K+, Cl- and C02.

The Electrolyte Reference Reagent is to provide reference points for Na+, K+, C1- and C02.

The C02 Acid Reagent is to release C02 from serum samples.

The Calibrators are used for the calibration of the CX ISE Modules for the quantitative determination of Na+, K+ Cl+and C02 in serum samples.

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

✓
_

Prescription Use (Per 21 CFR 801.109) OR

Over-The-Counter Use · (Optional Format 1-2-96)

Dean
Coopy
(Division Sign-Off)
Division of Clinical Laboratory Devices
16. 26364

Regulation Number and Section

§ 862.1665 Sodium test system.

(a)
Identification. A sodium test system is a device intended to measure sodium in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.(b)
Classification. Class II.