The Wescor ChloroChek Chloridometer test system is intended for the quantitative in vitro diagnostic determination of chloride in human sweat using the principle of coulometric titration. Sweat chloride measurements are used in the diagnosis of Cystic Fibrosis. It is for use in Clinical Laboratory settings. The Wescor ChloroChek Chloridometer test system consists of the ChloroChek Chloridometer and the ChloroChek Reagent Set.

The ChloroChek Reagent Set (SS-248) is to be used on the ChloroChek. It is used as the titration matrix during the titration process.

The 100 mmol/L NaCl/H2O Standard Solution (SS-251), is to be used on the ChloroChek. It is used as a calibration verifier, and quality control solution.

The Wescor Sweat Controls (SS-150), levels #1, #2, and #3, are to be used on the ChloroChek. They are used as quality control solutions.

Device Description

The CHLOROCHEK™ Chloridometer® test system includes the ChloroChek Chloridometer analyzer and the ChloroChek Reagent Set. The system is for in-vitro diagnostics intended to measure the level of chloride in human sweat. It is a bench top chloride titrator for laboratory determinations of chloride concentrations.

AI/ML Overview

The Wescor CHLOROCHEK™ Chloridometer® test system is intended for the quantitative in vitro diagnostic determination of chloride in human sweat. Sweat chloride measurements are used in the diagnosis of Cystic Fibrosis.

Here's an analysis of the acceptance criteria and study information provided:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance
Measuring Range	10 mmol/L to 160 mmol/L
Precision	Total
	Low concentration (24mmol/L): CV = 4.0%
	Medium concentration (49mmol/L): CV = 1.7%
	High concentration (100mmol/L): CV = 1.0%
	100 mmol/L standard solution: CV = 1.0%
	10 mmol/L standard solution: CV = 5.6% (SD 0.6 mmol/L)
Method Comparison (vs. Predicate Device)	y = 0.9992x + 0.8754, r² = 0.9886
	Range tested (non-spiked and spiked): 8.0 to 642 U/L

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

The provided document describes a precision study and correlation studies for the device.

Precision Study Test Set: The study tested three sweat levels (low, medium, high), a 100 mmol/L standard solution, and a 10 mmol/L standard solution. Specific numbers of individual samples for each level are not explicitly stated, but it involved multiple measurements over 10 days.
Method Comparison Test Set: The range tested for the method comparison was 8.0 to 642 U/L (non-spiked and spiked). The specific number of samples (e.g., patient samples, spiked samples) used for this comparison is not explicitly stated.
Data Provenance: The document does not specify the country of origin of the data or whether the study was retrospective or prospective. It implies the studies were conducted by the manufacturer, ELITechGroup Wescor.

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

For an in vitro diagnostic device measuring a quantitative value, the "ground truth" is typically the reference method or the true concentration of the analyte, rather than expert consensus on interpretation.

In the context of the precision study, the ground truth is based on the known concentrations of the standard solutions and the established values of the sweat control levels.
For the method comparison study, the ground truth is the measurement obtained by the predicate device (Buchler Instruments, Chloridometer®).
Therefore, the concept of "experts used to establish ground truth" with specific qualifications is not applicable in the same way it would be for image-based diagnostic systems.

4. Adjudication Method for the Test Set

As this is a quantitative measurement device for a chemical analyte, an adjudication method in the sense of resolving discrepancies between expert interpretations is not applicable. The performance is assessed against established quantitative metrics (precision, correlation with a predicate).

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

No, an MRMC comparative effectiveness study was not done. This device is a standalone in vitro diagnostic instrument, not an AI-assisted diagnostic tool that requires human interpretation. The concept of human readers improving with or without AI assistance is not applicable here.

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

Yes, a standalone performance study was done. The entire precision study and method comparison study describe the performance of the Wescor CHLOROCHEK™ Chloridometer® test system as a standalone device, measuring chloride levels without human interpretation as the primary outcome. The system produces a quantitative value (mmol/L) directly.

7. The Type of Ground Truth Used

The ground truth for the precision study was established using standard solutions (10 mmol/L, 100 mmol/L NaCl/H2O) and sweat control solutions (levels #1, #2, and #3) with known chloride concentrations.
The ground truth for the method comparison study was the results obtained from the predicate device (Buchler Instruments, Chloridometer®), which serves as the reference method for comparison.

8. The Sample Size for the Training Set

The document does not provide information on a "training set" in the context of machine learning or AI. This device is an instrument for chemical analysis, not a learning algorithm. The studies conducted (precision, method comparison) are verification and validation studies of the instrument's performance.

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

As there is no "training set" defined for this type of device, this question is not applicable.

Summary

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MAR 27 2013

Introduction	According to the requirements of 21 CFR 807.92, the following information provides sufficient detail to understand the basis for a determination of substan- tial equivalence.The assigned 510(k) number is: K121823
Submitter	ELITechGroup Wescor ("Wescor")
Address	370 W 1700 S, Logan, UT 84321 USA
Phone number	435-752-6011
Fax number	435-752-4127
Contact	Dawn T. Perdue (Email: d.perdue@elitechgroup.com)
Alternat Contact	Dennis Briscoe, (d.briscoe@elitechgroup.com
Date of Preparation	Thursday, March 21, 2013
Trade/proprietary Name:	ChloroChek Chloridometer test system (containing;)CHLOROCHEK TM Chloridometer ®1CHLOROCHEK TM Reagent Set
Common or Usual Name:	Clinical chloride analyzer, Chloride test system, Sweat Chloride Analyzer,Chloridometer ®, chloride coulometric

Requiation	Name	Classification	Productないという。Code	Panel®
21 § 862.1170	Chloride test system		JFS	(75) Chemistry
21 § 862.1660	Quality Control	, reserved	JJX	(75) Chemistry

Establishment Information:

The establishment registration number for ELITechGroup Wescor USA is 1717966. The owner operator number for ELITechGroup North America (Wescor, Logan, UT, USA) is 1717966.

1 *ChloroChek" is a registered trademark of Wescor Inc. "Chloridometer" is a registered trademark of LABCONCO that has been licensed exclusively to Wescor.

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Predicate device:

Predicate Instrument		510(k) Number
Buchler Instruments (Labconco), Chloridometer®.		K760394
Substantial Equivalence:	The Wescor CHLOROCHEK™ Chloridometer® test system (Model 3400with associated reagent set (SS-248), is an in vitro diagnostic devicewhich has been developed by Gonotec in Germany and is currently beingOEM by. ELITechGroup Wescor. It has been demonstrated that theCHLOROCHEK™ Chloridometer® test system is substantially equivalentto the predicate device Buchler Instruments, Chloridometer® (now ownedby Labconco) cleared under K760394.Wescor ChloroChek ™ Reagent Set (SS-248) contains (a) ChloroChek ™Acid Buffer solution, a stabilizer (SS-248ABS), (b) ChloroChek ™ Gelatinsolution (SS-248GS), and (c) Wescor Standard solution 100mmol/LNaCl/H2O, (SS-251) which is used during the conditioning phase.
Device description:	The CHLOROCHEK™ Chloridometer® test system includes the Chloro-Chek Chloridometer analyzer and the ChloroChek Reagent Set. The sys-tem is for in-vitro diagnostics intended to measure the level of chloride inhuman sweat. It is a bench top chloride titrator for laboratory determina-tions of chloride concentrations.
Performance Standards:	To date, no performance standards that affect this device have beenfinalized under Section 514 of the Act.
Intended Use:	See Indications for Use
Indications for Use:	The Wescor ChloroChek Chloridometer test system is intended for the quantitativein vitro diagnostic determination of chloride in human sweat using the principle ofcoulometric titration. Sweat chloride measurements are used in the diagnosis ofCystic Fibrosis. It is for use in Clinical Laboratory settings. The Wescor Chloro-Chek Chloridometer test system consists of the ChloroChek Chloridometer and theChloroChek Reagent Set.The ChloroChek Reagent Set (SS-248), is to be used on the ChloroChek. It is usedas the titration matrix during the titration process.The 100 mmol/L NaCl/H2O Standard Solution (SS-251), is to be used on theChloroChek. It is used as a calibration verifier, and quality control solution.

Section 5- 510(k) Summary

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Comparison to Predicate device:

Difference
	WescorCHLOROCHEK™ Chloridometer®test system	Predicate deviceBuchler Instruments, (Labconco)Digital Chloridometer®
Sample Type	Samples of human sweat	Manual lists sweat, serum, plasma, andurine.
Sample Size	10 uL	10 uL on LOW range setting100 uL on HIGH range setting
On board stability	No on board storage.	No on board storage.
	Working solution in open container re-placed each session at least daily.	Working solution good for eight hours atroom temperature.
Calibration of instrumentFrequency	Factory calibrated. Calibration is notrequired by the user. Return the instru-ment for service if the following occurs:	Factory calibrated and users can adjust iferror exceeds specifications.
	1) Not able to condition even afterelectrodes have been cleaned andor replaced.	Conditioning and control is conductedeach day.
	2) Correct quality control valueswhile using Sweat Control Solu-tions (SS-150) are not achieved.
	Conditioning and control steps are per-formed whenever the WORKINGSOLUTION is replaced and thus 24hrs.See manual for specific procedure.
Method comparison	y=.9992x + 0.8754r2= 0.9886range tested (non-spiked and spiked): 8.0to 642 U/L	y=0.99x +1.01 U/Lr2= 0.9966range: 3.70 to 671.80 U/L
Similarities
	WescorCHLOROCHEK™ Chloridometer®test system	Predicate deviceBuchler Instruments, (Labconco)Digital Chloridometer®
Intended use/Indications forUse	The Wescor ChloroChek Chloridometer testsystem is intended for the quantitative in vitrodiagnostic determination of chloride in humansweat using the principle of coulometric titra-tion. Sweat chloride measurements are used inthe diagnosis of Cystic Fibrosis. It is for use inClinical Laboratory settings. The WescorChloroChek Chloridometer test system con-sists of the ChloroChek Chloridometer and theChloroChek Reagent Set.The ChloroChek Reagent Set (SS-248), is tobe used on the ChloroChek. It is used as thetitration matrix during the titration process.The 100 mmol/L NaCl/H2O Standard Solution(SS-251), is to be used on the ChloroChek. Itis used as a calibration verifier, and qualitycontrol solution.The Wescor Sweat Controls (SS-150), levels#1, #2, and #3, are to be used on the Chloro-Chek. They are used as quality control solu-tions.	Same,(Manual also lists plasma, serum, andurine.)
Reagent storage	There is a ChloroChek™ Reagent Set whichcontains 1 bottle of ChloroChek™ GelatinSolution and 37 flasks of ChloroChek™ AcidBuffer Solution. The 1 bottle of ChloroChek™Gelatin Solution is dispensed equally into eachof the 37 flasks of ChloroChek™ Acid BufferSolution to make the WORKINGSOLUTION.Storage of ChloroChek™ Gelatin Solution isat 50-77°F (10-25°C). The ChloroChek™Gelatin Solution is stable until the expiry datestated on the label.Storage of the ChloroChek™ Acid BufferSolution is 50-86°F (10-30°C). The Chloro-Chek™ Acid Buffer Solution is stable untilthe expiry date stated on the label.Storage of the WORKING SOLUTION is 50-77°F (10-25°C). The WORKINGSOLUTION is stable for 24 hours once pre-pared and must be prepared each day beforeuse with the ChloroChek™.	SimilarThere are two solutions supplied withtheir instrument. One is a singlebottle of Chloridometer™ Acid Re-agent, which is a complete reagentsolution to which the sample is addedfor titration. Storage of this Chlori-dometer Acid Reagent is at roomtemperature, with an expiry date thatis printed on the bottle label, Thesecond solution supplied is a GelatinReagent which is combined with anAcid solution and can be used as asubstitute for the Acid Reagent. TheGelatin Reagent is stored at roomtemperature and expiration date isprinted on the bottle. The combinedGelatin Reagent plus the preparedacid solution can be stored underrefrigeration for up to six (6) monthsor kept at room temperature for eight(8) hours.
		Similarities
	WescorCHLOROCHEKTM Chloridometer®test system	Predicate deviceBuchler Instruments, (Labconco)Digital Chloridometer®
Resolution	1 mmol/L over 20 second measurement duration	(Same)1 mEq/L over a 20 second measurement duration
Solution appearance	Liquid, ready to use	Same
Expected values of Cl-	Infant (0-6 months)Normal range ≤29 mmol/LIntermediate range 30-59 mmol/LIndicative of CF range ≥ 60 mmol/L	Same
	Beyond Infancy (6 months-18 years)Normal range ≤39 mmol/LIntermediate range 40-59 mmol/LIndicative of CF range ≥ 60 mmol/L
	Adults (>18 years)*Normal range ≤39 mmol/LIntermediate range 40-59 mmol/LIndicative of CF range ≥ 60 mmol/L
	* Exact ranges for adults are not fully defined.See CLSI C34-A3 for more information.
Measuring range	10 mmol/L to 160 mmol/L	Same
Precision	TotalLow concentration (24mmol/L)CV=4.0%	not specified
	Medium concentration (49mmol/L)CV=1.7%
	High concentration (100mmol/L)CV= 1.0%
	100 mmol/L standard solutionCV= 1.0%
	10mmol/L standard solutionCV=5.6%
	Similarities
	WescorCHLOROCHEK™ Chloridometer®test system	Predicate deviceBuchler Instruments, (Labconco)Digital Chloridometer®
Principle of operation	Coulometric titration	Same
Limitation	Halides (halogens) such as fluoride, bromide, or iodide will interfere and cause an elevated reading. CLSI acknowledges this in the C34-A3 guideline. “In addition to chloride, other halides such as bromide and iodide are also detected using a Chloridometer. Therefore, if a sweat sample contains other halides in addition to chloride, they will be detected and can falsely elevate the sweat chloride result.” (1). Halides may be present in lotions or creams, so it is important that the patients’ skin is properly cleaned prior to collecting the sweat. Refer to the CLSI C34-A3 guidelines for cleaning the skin prior to pilocarpine iontophoresis.	Same

Section 5- 510(k) Summary

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Section 5- 510(k) Summary

Wescor CHLOROCHEK™ Chloridometer®

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Conclusion:

A precision study was performed using two instruments, two lots of reagents, three operators, over 10 days on the three sweat levels, the 100mmol/L standard solution and a 10 mmol/L standard solution. The precision at the lower end of the measuring range, 10 mmol/L standard solution, was tested by 3 operators on 2 instruments with 2 reagent lots over 10 days and measured to be SD 0.6 mmol/L, 5.6% CV.

The linear range of the method (10-160 mmol/L) is compatible with the measurement of normal and pathological samples and the precision performance meets acceptance criteria. Likewise, correlation studies versus the predicate device meet acceptance criteria.

The data demonstrate the Wescor CHLOROCHEK™ Chloridometer® test system (analyzer (Model 3400 and associated ChloroChek Reagent Set (SS-248), [K121823], are substantially equivalent to the predicate device cleared under K760394.

The data demonstrate that the system is appropriate for its intended use and does not raise new issues of safety or effectiveness.

Section 5- 510(k) Summary

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized caduceus symbol, which is a staff with two snakes coiled around it, topped with a pair of wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular fashion around the caduceus.

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

March 27, 2013

Wescor, Inc. c/o Dawn T. Perdue 370 West 1700 South Logan, UT 84321

Re: K121823

Trade/Device Name: Wescor ChloroChek Chloridometer Regulation Number: 21 CFR 862.1170 Regulation Name: Chloride Test System Regulatory Class: II Product Code: JFS, JJX Dated: January 31, 2013 Received: February 14, 2013

Dear Ms. Perdue:

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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to 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); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); 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.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for

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Page 2-Ms. Perdue

the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803). please go to

http://www.fda.gov/MedicalDevices/Safety/ReportalProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

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) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely vours.

Carol C. Benson -S for

Courtney H. Lias, Ph.D. Director Division of Chemistry and Toxicology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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Indication for Use

510(k) Number (if known): K121823

Device Name: Wescor ChloroChek Chloridometer

Indication For Use:

The ChloroChek Reagent Set (SS-248) is to be used on the ChloroChek. It is used as the titration matrix during the titration process.

The 100 mmol/L NaCl/H2O Standard Solution (SS-251), is to be used on the ChloroChek. It is used as a calibration verifier, and quality control solution.

The Wescor Sweat Controls (SS-150), levels #1, #2, and #3, are to be used on the ChloroChek. They are used as quality control solutions.

And/Or

Prescription Use × (21 CFR Part 801 Subpart D) Over the Counter Use (21 CFR Part 801 Subpart C)

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

Concurrence of CDRH, Office of In Vitro Diagnostics and Radiological Health (OIR)

Ruth A. Chesler -S

Division Sign-Off Office of In Vitro Diagnostics and Radiological Health

510(k) K121823

Regulation Number and Section

§ 862.1170 Chloride test system.

(a)
Identification. A chloride test system is a device intended to measure the level of chloride in plasma, serum, sweat, and urine. Chloride measurements are used in the diagnosis and treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis.(b)
Classification. Class II.