The products encompassed by this request are intended for invitro diagnostic use and are intended for use in calibrating Nat, K+, Cli electrodes in Roche Cobas ISE module. Roche is the original equipment manufacturer for the analyzer and predicate reagents. phoenix electrolyte calibration set is intended for use in playe of like named products manufactured by Roche Diagnostics.

Device Description

The products encompassed by this 510 (k) submission are Class II (75 JIX) In Vitro Diagnostic Solutions manufactured by pHoenix Diagnostics, Inc., 8 Tech Circle, Natick, MA 01760. The Calibration Set consists of 2 levels and is intended for use in calibrating Na*, K* and CI on the Roche® Cobas™ ISE Module. Roche Diagnostics is the original equipment manufacturer (OEM) of the system. The pHoenix Calibrator Reagents are intended to serve as direct replacements to like named products manufactured by Roche Diagnostics. pHoenix Product 17-200 and 17-201 are equivalent to Roche Product 44224. pHoenix uses a similar composition, description and packaging design as that used by Roche Diagnostics in its products.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the pHoenix Electrolyte Calibration Set for the Roche® Cobas™ ISE Module, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the comparison to Roche products, which are the predicate. The performance of the pHoenix calibrators is demonstrated through precision and accuracy studies.

Category	Performance Metric	Acceptance Criteria (Implied)	Reported pHoenix Device Performance
Precision	Standard Deviation (STD) and Coefficient of Variation (CV%) for Na+, K+, Cl-	Acceptable analytical variation consistent with clinical requirements and predicate device performance. (Not explicitly stated in numerical terms, but "typical results" imply acceptable ranges.)	Level 1: Na+: Total STD 1.50, CV% 1.20; Run to Run STD 0.80, CV% 0.60 K+: Total STD 0.110, CV% 5.0; Run to Run STD 0.040, CV% 1.5 Cl-: Total STD 0.60, CV% 0.60; Run to Run STD 0.25, CV% 0.30 Level 2: Na+: Total STD 1.20, CV% 0.70; Run to Run STD 0.70, CV% 0.40 K+: Total STD 0.07, CV% 1.0; Run to Run STD 0.04, CV% 0.6 Cl-: Total STD 0.80, CV% 0.50; Run to Run STD 0.60, CV% 0.40
Accuracy	Correlation Coefficient (R)	"Performance equivalence" to Roche Diagnostic products, implying a high correlation (e.g., R ≥ 0.97 or 0.98 for clinical assays) to predicate device results.	Na+: 0.990 K+: 0.990 Cl-: 0.980
	Slope	Close to 1.0 (indicating proportional agreement)	Na+: 1.01 K+: 0.980 Cl-: 0.990
	Intercept	Close to 0.0 (indicating no significant constant bias)	Na+: 1.1 K+: 1.1 Cl-: 1.1

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

Precision Study Test Set:
- Sample Size: 2 levels of serum controls, measured 2 runs per day, 2 times per run for 20 days.
  - For "Total" precision, N = 80 (2 runs/day * 2 times/run * 20 days).
  - For "Run to Run" precision, N = 20 (20 days).
- Data Provenance: Not explicitly stated, but the study was conducted internally by pHoenix. It's prospective, as they "collected" the data following NCCLS Guideline EP5-T. No country of origin is mentioned beyond the company's location in Natick, MA, USA.
Accuracy (Correlation) Study Test Set:
- Sample Size: N = 50 for Na+, K+, and Cl- analysis. The samples included patient serum samples and control samples.
- Data Provenance: Not explicitly stated, but the study was conducted internally by pHoenix. It appears retrospective/concurrent, comparing results from two calibration methods on the same samples. No country of origin beyond the company's location in Natick, MA, USA.

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

This type of device (electrolyte calibrator) does not typically involve expert review for establishing ground truth in the way medical imaging or pathology devices do. The "ground truth" for the accuracy study is the measurement obtained when calibrating the Roche® Cobas™ ISE Module with Roche Diagnostics' own, predicate calibrator products. The performance of the predicate device is assumed to be the established "truth" or reference standard. No external human experts are mentioned for establishing this ground truth.

4. Adjudication Method for the Test Set

Not applicable. This is not a study involving subjective interpretation or expert consensus. The comparison is objective, based on instrument readings.

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 a device designed for human interpretation or an AI-assisted diagnostic tool. It's a calibrator for an automated laboratory instrument.

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

Yes, in a way. The performance studies for both precision and accuracy were conducted on the automated Roche® Cobas™ ISE Module, which is an "algorithm only" or automated system. The pHoenix calibrators are used by this automated system. The evaluation assesses the performance of the calibrators through the instrument's measurements, independent of human intervention in the result generation itself.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The ground truth for the accuracy study was the results obtained from the predicate device's calibrators (Roche Diagnostics products) when used with the same Roche® Cobas™ ISE Module. This is a form of reference standard comparison against an established, legally marketed product.

8. The Sample Size for the Training Set

Not applicable. This device is a calibrator, not a machine learning algorithm that requires a training set. The performance is evaluated based on its physical and chemical properties and how it interacts with the instrument.

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

Not applicable, as there is no training set for this type of device.

Summary

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K020129

510 (k) Summary

pHoenix Electrolyte Calibration Set for the Roche® Cobas™ ISE Module

The pHoenix products stated are currently cleared under docket K902675. Information herein will support pHoenix's position to extend the intended use of these products to the Roche® Cobas™ ISE Module. The Roche® Cobas™ ISE Module measures Na*, K*, and CI by using Ion Selective Electrode Technology. The pHoenix Calibrator Reagents are intended to serve as direct replacements to like named products manufactured by Roche Diagnostics. pHoenix Product 17-200 and 17-201 are equivalent to Roche Product 44224.

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

Through a method comparison where results obtained on Roche® Cobas™ ISE . Module Chemistry Systems calibrated with pHoenix products and compared with results obtained on the same analyzer calibrated with Roche products; and
Through a precision study where pHoenix products were installed on Roche® . Cobas 114 ISE Module and samples were measured over multiple runs.

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 a on Roche® Cobas™ ISE Module calibrated with pHoenix calibrator reagents. The NCCLS Guideline for precision evaluation, EP5-T, was followed. Typical results are as follows:

Analyte		N	Mean	STD	CV%	Min	Max
Na+	Total	80	120.0	1.50	1.20	117	122
	Run to Run	20	120.0	0.80	0.60	118	122
K+	Total	80	2.0	0.110	5.0	1.85	2.15
	Run to Run	20	2.0	0.040	1.5	1.90	2.10
Cl-	Total	80	100.0	0.60	0.60	97	102
	Run to Run	20	100.0	0.25	0.30	98	101

Level 2

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510 (k) Summary Cont.

Level 4

Analyte		N	Mean	STD	CV%	Min	Max
Na+	Total	80	165	1.20	0.70	162	167
	Run to Run	20	165	0.70	0.40	163	167
K+	Total	80	6.50	0.07	1.0	6.4	6.6
	Run to Run	20	6.50	0.04	0.6	6.4	6.5
Cl-	Total	80	146	0.80	0.50	144	148
	Run to Run	20	146	0.60	0.40	125	148

Accuracy by Correlation with Roche Standard Reagents

Correlation data was collected from patient serum samples and control samples for Na", K* and CI measured on a Roche® Cobas™ ISE Module calibrated with pHoenix reagents as compared with Roche reagents separately. A Linear Regression Analysis was performed using pHoenix data as the independent X Variable and Roche 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	1.01	1.1	0.990	120 - 180
K+	50	0.980	1.1	0.990	2.5 - 7.5
Cl-	50	0.990	1.1	0.980	78 - 120

I hope you find this information useful and informative.

Ram Nunna, President

1/11/02

Data

Date

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Image /page/2/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 representing the department's mission. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular fashion around the eagle.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

FEB 01 2002

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

Re: K020129

Trade/Device Name: pHoenix Electrolyte Calibration Set for the Roche® Cobas™ ISE Module Regulation Number: 21 CFR 862.1150 Regulation Name: Calibrator Regulatory Class: Class II Product Code: JIX Dated: November 2, 2001 Received: January 14, 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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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/odrh/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): K020129

Device Name: pHoenix Electrolyte Calibration Set for the Roche® Cobas™ ISE Module

Indications For Use:

Intended Use:

(Division Sign-Off)
Division of Clinical Laboratory Devices

510(k) Number	K020129
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(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)

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

Regulation Number and Section

§ 862.1150 Calibrator.

(a)
Identification. A calibrator is a device intended for medical purposes for use in a test system to establish points of reference that are used in the determination of values in the measurement of substances in human specimens. (See also § 862.2 in this part.)(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.