The Terumo Khuri™ Myocardial pH Monitoring System is intended for use in monitoring local tissue pH and temperature, typically during procedures in which specific tissues may be subjected to conditions which may result in ischemia, such as the myocardium, during cardiac operations. These parameters are displayed at 37°C corrected value. For documentation purposes, the integral printer provides a hard copy of displayed parameter.

Device Description

The Terumo Khuri™ Myocardial pH Monitoring System (Khuri MpH system) is an AC-powered (battery support for memory retention), microprocessor-based device consisting of a monitor, sensor and interface module'. The myocardial pH sensor will consist of two pH measurement probe electrodes and a reference electrode for the purpose of monitoring continuous myocardial tissue pH and temperature during cardiac surgery. The system uses electrochemical technology to measure the hydrogen ion content of the myocardial tissue, and report that information via electrical cable back to the monitor, where a processing unit coverts the electrical signal into pH units for display on the monitor.

The Khuri MpH system Monitor consists of a single board computer and a dedicated circuit that contains digital circuitry to interface with the interface module that connects to the sensor (pH electrodes and reference probe). The system will have an LCD flat touch screen display that will control the mode and operation of the monitor. The monitor will have a printer that will enable the user to print out case results. The monitor will be able to be mounted on a vertical pole or rest on a flat surface.

Each Khuri MpH system Sensor consists of two pH electrodes and one reference electrode. The pH electrodes are designed with a pointed tip for insertion into tissue with minimal resistance. The pH electrode consists of a closed end glass tube made from pH sensitive glass. The tube is filled with a phosphate based internal buffering solution in which a silver wire coated with silver chloride is inserted. The wire is attached to a cable, which is encased in an electrically shielded sheath and attaches to the monitor. The tip of the glass is pointed to allow easy insertion in to the myocardial tissue during use. The thermistor is a metal oxide ceramic tip. which is imbedded in the plastic surrounding the rear of the glass tube.

A reference electrode is used to complete the circuit. The reference electrode consists of an Ag/AgCl wire inserted into a plastic tube of KCI electrolyte solution. The front end of the tube is tapered to a small diameter to facilitate insertion into the tissue (usually near the sternum) during use. It is plugged with a semi-permeable material that prevents bulk leakage of fluid but maintains electrical contact with the patient during pH measurement. The wire protrudes from the sealed back end of the tube and is attached to a cable, which connects to the monitor.

The analog voltage signal from the sensor is fed into an interface module that amplifies and conditions the analog signal to remove any interfering noise. The analog signal is then converted into digital information in the A to D converter. This digital signal is then fed from the interface module to the monitor where a conversion algorithm, in the monitor, is used to convert digital information into pH units. The values are then displayed on the monitor screen.

AI/ML Overview

The provided document does not contain acceptance criteria or a study proving the device meets specific acceptance criteria in the manner typically seen for performance evaluation studies of diagnostic or AI-driven medical devices.

Instead, this is a 510(k) summary for a medical device (Terumo Khuri Myocardial pH Monitoring System) seeking substantial equivalence to a predicate device. The "study" described is a nonclinical performance comparison to demonstrate that the new device is substantially equivalent to the predicate device.

Here's a breakdown based on the request, with explanations for why certain information is not present:

Acceptance Criteria and Device Performance

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance
Not explicitly stated as quantitative performance metrics (e.g., accuracy, sensitivity, specificity). The primary "acceptance criterion" for this 510(k) submission is that the device "perfo rms as intended according to its performance specifications" and is "substantially equivalent to the predicate device."	The document states: "The Khuri MpH system performs as intended according to its performance specifications. The Khuri MpH system is substantially equivalent to the predicate device."

Explanation: This is a Class II device (pH monitor), and the 510(k) pathway for substantial equivalence often relies on demonstrating that the new device's technological characteristics and performance are comparable to a legally marketed predicate, rather than meeting specific quantitative diagnostic performance thresholds (like sensitivity/specificity for an AI algorithm). The nonclinical tests were likely focused on engineering specifications, physiological measurements (pH and temperature accuracy), and safety, rather than a clinical outcome or diagnostic accuracy study.

Study Details

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Sample Size for Test Set: Not specified. The document refers to "exhaustive testing" and comparison with the predicate device's performance characteristics. This implies laboratory or bench testing, possibly animal studies, but not a human clinical test set in the conventional sense for diagnostic accuracy.
Data Provenance: Not specified. Given it's "nonclinical performance," it would likely be laboratory or internal testing data, not clinically derived patient data.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Number of Experts: Not applicable/Not specified. Ground truth in this context would likely be established by known chemical/physical standards (e.g., buffer solutions of known pH) or controlled physiological environments, not human expert interpretation of images or patient data.
Qualifications of Experts: Not applicable/Not specified.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Adjudication Method: Not applicable. This type of device (pH monitor) does not involve subjective interpretation requiring adjudication of results from multiple readers.

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

MRMC Study: No. This device is a direct measurement tool, not an imaging or AI-assisted diagnostic device where human interpretation is a primary component.

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

Standalone Performance: Yes, in a sense. The "nonclinical performance" reported is the standalone performance of the device itself (the monitor and sensor system) in measuring pH and temperature, independent of human interpretation or assistance in the measurement process. There is no complex algorithm like in AI that would have a human-in-the-loop scenario. The algorithm mentioned only converts digital signals to pH units.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

Type of Ground Truth: Not explicitly stated but would most likely be known physical/chemical standards (e.g., certified pH buffer solutions) for calibration and accuracy checks. In ex vivo or in vivo physiological testing (if conducted), the "ground truth" for temperature would be a calibrated thermometer, and for pH, potentially another highly accurate, validated pH measurement system.

8. The sample size for the training set

Training Set Sample Size: Not applicable/Not specified. This device describes electrochemical technology and a conversion algorithm from electrical signal to pH units. There is no mention of a machine learning or AI model that requires a "training set" in the conventional sense for pattern recognition or diagnostics. The "algorithm" is a deterministic conversion based on established electrochemical principles.

9. How the ground truth for the training set was established

Ground Truth for Training Set: Not applicable. As there's no machine learning training set, this question is not relevant. The "ground truth" for the device's fundamental function (converting electrical signals to pH) would be based on the physical chemistry of the pH electrodes and the calibration process using known pH standards.

Summary of the "Study" from the Document:

The provided text details a nonclinical performance evaluation comparing the new "Terumo Khuri Myocardial pH Monitoring System" to its predicate device, the "Khuri Regional Tissue pH Monitor."

Purpose: To demonstrate substantial equivalence to the predicate device.
Methodology: "The performance characteristics of the Khuri MpH system were exhaustively tested and compared with the performance characteristics of the predicate device."
Key Finding: "All new and existing performance characteristics of the Khuri MpH system have been validated." And concluded, "The Khuri MpH system performs as intended according to its performance specifications. The Khuri MpH system is substantially equivalent to the predicate device."

This type of submission focuses on validating the engineering and functional integrity of the device in comparison to an existing standard, rather than a clinical trial or AI performance study with traditional diagnostic metrics.

Summary

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K020967
PG 1 OF 3

510(k) Summary

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92. The assigned 510(k) number is

Terumo Cardiovascular Systems Corporation Submitter's Name: Submitter's Address: 1311 Valencia Avenue, Tustin CA 92780 Contact Person: Steve Arick Phone Number: (734) 741-6238 FAX Number: (734) 663-5062 March 15, 2002 Summary Date:

Device Trade Name: Terumo Khuri™ Myocardial pH Monitoring System

Device Classification Name: Device Classification Name:

Predicate Devices: K862114 Khuri Regional Tissue pH Monitor

Device Description:

Image /page/0/Picture/9 description: The image shows two electronic devices on a wooden surface. The device on the left has a screen and a white rectangular component connected by a cable. The device on the right has a more complex structure with visible internal components and a coiled cable. Both devices appear to be related, possibly part of the same system, and are positioned against a neutral background.

Terumo Khuri™ Myocardial pH Monitoring System

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The glass pH electrode is the most common method used to obtain accurate pH measurements. Due to the nature of the glass used in the electrode, an electric potential is developed across the glass. This potential is proportional to the difference in pH between an analyte solution in contact with the exterior surface of the glass and the phosphate based internal buffering solution.

Indications for Use:

The Khuri MpH system is intended for use in monitoring local tissue pH and temperature, typically during procedures in which specific tissues may be subjected to conditions which may result in ischemia, such as the myocardium, during cardiac operations. These parameters are displayed at 37°C corrected value. For documentation purposes, the integral printer provides a hard copy of displayed parameter.

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Technological Characteristics:

The Khuri MpH system is identical to the technology found in the Khuri Regional Tissue pH Monitor. The Khuri MpH system is identical to its predicate device except in the following ways:

Placement of the thermistor for temperature measurement is now integrated in the pH measuring electrode. With the Khuri Regional Tissue pH monitor the temperature measurement was located in three separate 22-guage needle precision thermister temperature probes.
The Khuri MpH system Probe is intended for single-use only. The Khuri Regional Tissue pH monitor electrodes were designated to be reusable.
Line power: The Khuri MpH system runs off of AC line power. The Khuri Regional Tissue pH monitor was battery powered. The Khuri MoH system conforms to IEC 601-1 series.
The Khuri MpH system Sensor will be Gamma Radiation sterilized, where as the Khuri Regional Tissue pH Probes were Ethylene Oxide sterilized. However, both were sterilized according to the sterility assurance level of 10° therefore, there is no impact on safety and effectiveness.

Nonclinical Performance:

The performance characteristics of the Khuri MpH system were exhaustively tested and compared with the performance characteristics of the predicate device. All new and existing performance characteristics of the Khuri MpH system have been validated.

Conclusions from Nonclinical Tests:

The Khuri MpH system performs as intended according to its performance specifications. The Khuri MpH system is substantially equivalent to the predicate device.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo features the department's name, "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA," arranged in a circular pattern around a symbol. The symbol is a stylized representation of an eagle or bird-like figure, composed of three curved lines that suggest wings or feathers.

Public Health Service

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JUN 2 0 2002

Terumo Cardiovascular Systems Corporation c/o Mr. Steve Arick Regulatory Affairs Manager 1311 Valencia Avenue Tustin, CA 92780

Re: K020967

Trade Name: Terumo Khuri™ Myocardial pH Monitoring System Regulation Number: 21 CFR 868.1170 Regulation Name: Analyzer, Ion Hydrogen-Ion, (pH) Blood, Phase Indwelling Regulatory Class: Class II (two) Product Code: CBZ Dated: March 15, 2002 Received: March 25, 2002

Dear Mr. Arick:

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. Iisting 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.

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Page 2 - Mr. Steve Arick

Please be advised that FDA's issuance of a substantial equivalence determination does not niean 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.

This letter will allow you to begin marketing your device as described in your Section 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 21 CFR Part 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4646. 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 Part 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/cdrh/dsma/dsmamain.html

Sincerely yours,

Dala Tell

Donna-Bea Tillman, Ph.D. Acting Director Division of Cardiovascular and Respiratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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2.4 ODE Form, Indications for Use Statement

Page 1 _of 1

510(k) Number (if known): KOXO967

Device Name: Terumo Khuri™ Myocardial pH Monitoring System

Indications for Use:

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

Concurence of CDRH, Office of Device Evaulation (ODE)

Prescription Use
(Per 21 CFR 801.109)

(Optional Format 3-10-98)

(Posted July 1, 1998)

Division of Cardiovascular & Respiratory Devices
510(k) Number K020967

Regulation Number and Section

§ 868.1170 Indwelling blood hydrogen ion concentration (pH) analyzer.

(a)
Identification. An indwelling blood hydrogen ion concentration (pH) analyzer is a device that consists of a catheter-tip pH electrode and that is used to measure, in vivo, the hydrogen ion concentration (pH) in blood to aid in determining the patient's acid-base balance.(b)
Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Indwelling Blood Gas Analyzers; Final Guidance for Industry and FDA.”