The ABL835 FLEX analyzer is intended for: in vitro testing of pleural fluid samples for the pH parameter. The pH measurement of pleural fluid can be a clinically useful tool in the management of patients with parapneumonic effusions. Critical values: pH >7.3 is measured in uncomplicated parapneumonic effusions. All pleural effusions with a pH of <7.3 are referred as complicated parapneumonic effusions; they are exudative in nature.

Device Description

ABL835/ABL830/ABL825/ABL820/ABL815/ABL810/ABL805 FLEX analyzers are several models of the same analyzer for the measurement of blood gas, pH, electrolyte, metabolite, cooximetry, and expired air for the parameters p02 and pCO2. An additional indication, namely the measurement of pH in pleura fluids, has been introduced for the ABL835 FLEX analyzer. This additional indication is based on a further development of the software used in all ABL800 FLEX (and ABL700 before that).

AI/ML Overview

Here's an analysis of the provided text regarding the ABL835 FLEX analyzer and its acceptance criteria, structured to answer your questions:

The provided document describes the Radiometer ABL835 FLEX analyzer, specifically focusing on the new indication for measuring pH in pleural fluids. The acceptance criteria and performance studies are presented to demonstrate substantial equivalence to a predicate device.

1. Table of Acceptance Criteria and Reported Device Performance

The direct acceptance criteria values are not explicitly stated in a threshold format (e.g., "bias must be < X"). Instead, the document defines acceptance through comparison with a predicate device and established guidelines (NCCLS). The performance claims are related to precision and method comparison, demonstrating acceptable agreement with the predicate.

Performance Metric	Acceptance Criteria (Implied / Guideline)	Reported Device Performance (ABL835 FLEX)
Precision (Repeatability S₀)	Acceptable precision according to "NCCLS EP5-A2" guideline	pH 7.1: 0.013pH 7.3: 0.009pH 7.5: 0.005
Precision (Total Precision Sₓ)	Acceptable precision according to "NCCLS EP5-A2" guideline	pH 7.1: 0.029pH 7.3: 0.019pH 7.5: 0.027
Method Comparison (Slope)	Within 10% difference from predicate (implied acceptance)	1.063 (6.3% difference from ideal 1.0, which is ≤ 10%)
Method Comparison (Y-intercept)	Data coherence, 95% CI of regression includes identity line (implied acceptance)	-0.446; linear fit intersects identity line (X=Y) at pH 7.079. 95% Confidence Interval of linear regression covers the X=Y line from pH 7.0 to 7.5.
Method Comparison (Bias at critical point)	Considered acceptable, given sample nature and clinical context	At pH 7.3, ABL835 measures 0.0138 above Roche analyzer (considered acceptable).
Linearity (R-value)	Demonstrate linear fit of the method	R = 0.994

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

Precision Study:
- Sample Size:
  - pH 7.1: 244 observations
  - pH 7.3: 248 observations
  - pH 7.5: 248 observations
- Data Provenance: Not explicitly stated, but typically these samples would be prepared controls or simulated clinical samples in a laboratory setting for reproducibility. The document does not specify country of origin.
Method Comparison and Linearity Study:
- Sample Size: 58 samples (referred to as "patient samples" in the method comparison study and "58 samples" for linearity).
- Data Provenance: The method comparison study states it used "patient samples." The country of origin is not specified, nor is whether the data was retrospective or prospective.

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

The document does not mention the use of experts to establish ground truth for the quantitative pH measurements in the test set. Instead, the ground truth for method comparison is defined by comparison to a recognized predicate device (Roche Omni C) through direct measurement. For precision, the ground truth is against the expected value of the control material or sample being repeatedly measured.

4. Adjudication Method for the Test Set

No adjudication method is mentioned, as the studies involve direct quantitative measurements against a predicate device or for precision. This is not a study design where expert adjudication would typically be applied.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No MRMC comparative effectiveness study was conducted or mentioned in the provided text. The device is an automated analyzer, and the study focuses on its analytical performance rather than human interpretation with or without AI assistance.

6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop Performance)

Yes, the studies presented (Precision, Method Comparison, Linearity) are standalone performance studies. They evaluate the analytical performance of the ABL835 FLEX analyzer itself in measuring pH in pleural fluids, without human interpretation as part of the primary measurement.

7. Type of Ground Truth Used

Precision: The ground truth for precision is statistical (mean, standard deviation) derived from repeated measurements of samples with known characteristics.
Method Comparison/Linearity: The ground truth is defined by the measurements obtained from the predicate device, the Roche Omni C analyzer, for the same patient samples.

8. Sample Size for the Training Set

The document does not mention a "training set" in the context of device development. This suggests that the device does not employ machine learning or AI models that require explicit training data in the way, for example, an image recognition algorithm would. The device's operation is based on established electrochemical (potentiometric) principles.

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

As no training set is mentioned or implied for this type of device and submission, this question is not applicable. The device relies on physical and chemical principles, not data-driven machine learning models that require a "training set" with established ground truth.

Summary

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Image /page/0/Picture/1 description: The image shows the word "RADIOMETER" in bold, capital letters, followed by a circled "R" symbol. Above the word "RADIOMETER", there is a handwritten number "K110416". The number is written in a simple, clear font, and it appears to be a serial number or some other type of identification code.

Section 5

MAR 2 4 2011

510(k) Summary

1. Submitter Information

A. Establishment Registration: 3002807968

B. Manufacturing Site: Radiometer Medical ApS

C. Company Address: Aakandevej 21, DK-2700 Broenshoej, Denmark

D. Date Prepared: February 3, 2011

2. Contact Person

A. Jana S. Hellmann
B. Phone: (+45) 3827 3389
C. Fax: (+45) 3827 2727
D. Address: Aakandevej 21, DK-2700 Broenshoej, Denmark
E. E-mail: jana.hellmann@radiometer.dk

3. Application Correspondent

A. Søren Bøgestrand
B. Phone: (+45) 3827 3852
C. Fax: (+45) 3827 2727
D. Address: Aakandevej 21, DK-2700 Broenshoej, Denmark
E. E-mail: soren.bogestrand@radiometer.dk

4. Device Identification

A. Trade/Proprietary Name: ABL835 FLEX analyzer
B. Classification: Class II (21CFR & 862.1120)
C. Product Code: CHL.
D. Subsequent Codes: CEM, JGS, JFP, CGZ, CGA, KHP, CIG, MQM, GHS, GKR, KQI, JIX, JJY

5. Device Description

An additional indication, namely the measurement of pH in pleura fluids, has been introduced for the ABL835 FLEX analyzer.

This additional indication is based on a further development of the software used in all ABL800 FLEX (and ABL700 before that).

6. Intended Use (added with this submission)

In vitro testing of pleural fluid samples for the pH parameter.

7. Substantial Equivalence

Predicate:

A. Trade/Proprietary Name: Roche Omni C
B. Classification: Class II (21CFR § 862.1120)
C. Product Code: CHL.
D. K-Number: 050423

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Item	SE Device	Predicate Device
	ABL835 FLEX analyzer with pleural pH	Roche analyzerK050423
Indications for use	New indication for measuring of pH inpleural fluids	Same
Blood Gas Measurement	pH by potentiometry	Same
Calibration Method	Two-Point liquid calibration	Same
User interface	Menu driven touch screen	Same
Sensors	Traditional, discrete amperometric andpotentiometric sensors installed in theanalyzer	Same
Calibration and QCsolutions	Discrete bottles and ampoules	Same
Pleural fluid pHmeasuring range	7.0 - 7.5	Same

The ABL835 FLEX analyzer is substantially equivalent to the predicate device Roche Omni C (K050423) regarding the measurement of pH in pleural fluid.

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8. Performance Characteristics:

Precision study:

Repeatability and Device/Method Precision is evaluated according to "NCCLS Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guideline – Second Edition, EP5-A2, Vol. 24, No. 25".

Performance Claims for Precision Performance, Repeatability (Sg) and Total Precision (Sy)

pH	Number of Observations	Mean	Repeatability (S₀)	Total Precision (Sₓ)
7.1	244	7.150	0.013	0.029
7.3	248	7.290	0.009	0.019
7.5	248	7.517	0.005	0.027

The test verifies that the use of this new pleural fluid measuring mode produces pH results with acceptable precision.

Method Comparison:

Method comparison study has been conducted according to NCCLS guideline AP9-A2 "Method Comparison and Bias Estimation Using Patient Samples".

The slope of the linear fit to the data is 1.063 for the ABL835, and the intersection with the Yaxis is at -0.446. The linear fit intersects the identity line X = Y (and thus the Roche data) at pH 7.079. Furthermore, the graph clearly shows coherence between the ABL835 data and the Roche data in the sense that the X=Y line, representing the Roche data, lies within the 95% confidence interval of the linear regression, in the entire pathological range from pH 7.0 to 7.5, and the difference in slope of 6.3% is well within the 10% acceptance.

At the critical decision interval fluid treatment, namely around pH 7,3, the ABL835 device measures 0.0138 above the Roche analyzer. This bias is considered acceptable, taking into account the nature of the sample material, and the fact that the clinical decision point is not defined more accurately than is the case. This means that the difference of 0.0138 pHunits could be contained in the rounding of the data. Finally, the placement of the critical decision point varies regionally; at some hospitals pH 7.2 is considered the critical decision point.

Summarizing our findings, we find that the results of this test clearly demonstrate that the ABL835 analyzer correctly measures pH in pleural fluid, since the measurements show a good agreement with those of the predicate device.

Linearity:

The data to prove the linear fit of the method has been taken from the method comparison study.

The data points from the 58 samples lie sufficiently distributed in the pathological range, and form a straight line, when plotting the ABL835 pH values against the Roche pH values. An R value of 0.994 is found when doing a linear regression on the data, plotting randomly selected single ABL835 measurements against the Roche average of two measurements.

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Conclusion:

Taken the results from the performance studies and the comparison of the new device with the predicate devices into consideration, we believe that the ABL835 with pleural pH is as safe and effective as the predicate devices.

Calibration and Quality Control

Since the measuring technology for pH in pleural fluid is the same as in blood no new calibration or quality controls have been introduced for the new indication. The existing calibration and QC solutions are listed below.

Calibration

The following are the calibration solution relevant for the pH electrode.

S1820 Calibration Solution 1

Use: For calibration of the pH, electrolyte and metabolite electrodes in the ABL835 FLEX analyzer.

S1830 Calibration Solution 2

Use: For calibration of the pH, electrolyte and metabolite electrodes in the ABL835 FLEX analyzer.

Quality Controls

QUALICHECK5+/AutoCheck5+

Use: This quality control system can be used for quality control of the ABL835 FLEX analyzer from Radiometer.

Parameter	S7730/S7735Level 1	S7740/S7745Level 2	S7750/S7755Level 3	S7760/S7765Level 4
PH	7.1	7.4	7.6	6.8

OUALICHECK3+/AutoCheck3+

Use: This quality control system can be used for quality control of the ABL835 FLEX analyzer from Radiometer.

Parameter	S7330/S7335Level 1	S7340/S7345Level 2	S7350/S7355Level 3	S7360/S7365Level 4
PH	7.1	7.4	7.6	6.8

Range+ QUALICHECK

Use: Range+ QUALICHECK quality control systems can be used for quality control of the ABL77, ABL700 Series and ABL800 FLEX Series analyzers from Radiometer.

Parameter	S7930Level 1	S7940Level 2	S7950Level 3
PH	6.8	7.0	7.8

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Technology

The technology has not been altered for the new indication of measuring pH in pleural fluids.

Potentiometric Method

The potential of an electrode chain is recorded using a voltmeter, and related to the concentration of the sample (the Nernst equation).

The electrode chain consisting of a sample, electrode, reference electrode, voltmeter, membranes and electrolyte solutions.

The reference electrode maintains a stable, fixed potential against which other potential differences can be measured. The potential is not altered by sample composition.

The pH electrode (E777) is a pH-sensitive glass electrode. The pH-sensitive glass membrane is located at the tip and seals the inner buffer solution with a constant and known pH

Modes of Operation

The instrument is an automated, random access, stat instrument. The specimens are withdrawn from a sampling device and drawn into the closed fluid transport system within the instrument for analysis.

The FLEXQ (K043218) allows the capability of automatic sampling from up to three blood samplers. Automatic measurements are accomplished via bar coding on the patient samples. The required tests for the identified sample are retrieved from a networked server. If required, manual introduction of a blood sample may be performed as well.

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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 depiction of an eagle or bird-like figure with outstretched wings, positioned to the right. To the left of the bird, there is a circular border containing the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" in capital letters, arranged around the circumference of the circle.

Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993

Radiometer Medical ApS c/o Soren Bogestrand Regulatory Affairs Specialist Akandevej 21 Bronshoj, Denmark DK-2700

Re: K110416

Trade Name: Radiometer Medical ApS ABL835 FLEX analyzer Regulation Number: 21 CFR 8862.1120 Regulation Name: Blood gases (PCO2, PO2) and blood pH test system. . Regulatory Class: Class II Product Code: CHL Dated: February 3, 2011 Received: February 14, 2011

Dear Mr. Bogestrand:

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 Title 21, Code of 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 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 Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

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Page 2 -

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to party any notification" (21 CFR Part 807.97). For questions regarding the reporting of premier the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/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 tolli the (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

C.C.

Courtney Harper, Ph.D. 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):

Device Name:

ABL835 FLEX analyzer

Intended Use:

The ABL835 FLEX analyzer is intended for:

in vitro testing of pleural fluid samples for the pH parameter .

Indications for use:

The pH measurement of pleural fluid can be a clinically useful tool in the management of patients with parapneumonic effusions.

Critical values: pH >7.3 is measured in uncomplicated parapneumonic effusions. All pleural effusions with a pH of <7.3 are referred as complicated parapneumonic effusions; they are exudative in nature.

Prescription Use _ X (21 CFR Part 801 Subpart D)

And/Or

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 Diagnostic Device Evaluation and Safety (OIVD)

Carol Benseen

Division Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety

KII0416 510(k):

Regulation Number and Section

§ 862.1120 Blood gases (P

CO2 , PO2 ) and blood pH test system.(a)
Identification. A blood gases (PCO2 , PO2 ) and blood pH test system is a device intended to measure certain gases in blood, serum, plasma or pH of blood, serum, and plasma. Measurements of blood gases (PCO2 , PO2 ) and blood pH are used in the diagnosis and treatment of life-threatening acid-base disturbances.(b)
Classification. Class II.