The T-Tek Thrombin Time Reagent contains a lyophilized thrombin reagent, for use in the quantitative determination of thrombin time in citrated plasma. The thrombin time test is a one-stage quantitative test performed on diluted plasma samples in the general patient population. The thrombin time test is used to detect disorders of fibrinogen. The T-Tek, Thrombin Time Reagent should only be used in an appropriate clinical laboratory by qualified laboratory professionals.

Device Description

The T-Tek Thrombin Time Reagent contains a lyophilized thrombin reagent, for use in the quantitative determination of thrombin time in citrated human plasma. The thrombin time test is a one-stage quantitative clotting test performed on citrated plasma samples in the general patient population. The thrombin time test is used to detect disorders of fibrinogen. The T-Tek, Thrombin Time Reagent should only be used in an appropriate clinical laboratory by qualified laboratory professionals. The test may be performed manually, or using semi-automated and automated coagulation analyzers.

AI/ML Overview

Here's an analysis of the acceptance criteria and study proving device performance for the R2 Diagnostics T-Tek, based on the provided 510(k) premarket notification:

Note: This submission is for a medical reagent (thrombin time test) which typically focuses on chemical and functional equivalence to a predicate device, rather than the complex clinical performance metrics often seen with imaging AI devices. Therefore, some of the requested categories (e.g., MRMC studies, ground truth for training) are not directly applicable or explicitly detailed in this type of submission.

Acceptance Criteria and Reported Device Performance

Acceptance Criteria Category	Specific Criteria	Reported Device Performance
Correlation	Correlation coefficient ($r^2$) for abnormal patient plasma (photo-optical instrument)	$r^2 = 0.801$
	Slope (photo-optical instrument)	$0.848$
	Intercept (photo-optical instrument)	$3.466$
	Correlation coefficient ($r^2$) for abnormal patient plasma (mechanical instrument)	$r^2 = 0.800$
	Slope (mechanical instrument)	$1.204$
	Intercept (mechanical instrument)	$-4.904$
Precision (Within-run)	Coefficient of Variation (CV)	$< 3%$
Precision (Between-run)	Coefficient of Variation (CV)	$< 3%$

Note on Acceptance Criteria: The document implies these values (especially the correlation coefficients and precision benchmarks) were considered acceptable for establishing substantial equivalence to the predicate device. The comparison device, STA Thrombin 10, is reported to have CV's of less than 3% in its Instructions for Use, serving as a benchmark for the T-Tek's precision.

Study Details Proving Device Performance

Sample Size and Data Provenance:
- Test Set Sample Size: The exact number of plasma samples (normal, abnormal, and heparin therapy patients) tested for correlation studies is not explicitly stated in the provided document.
- Data Provenance: Not explicitly stated, but the "correlation studies at two sites" suggests clinical laboratory settings. It's likely retrospective in nature, using banked or collected patient samples. The country of origin is not specified but implicitly assumed to be the USA, given the applicant and regulatory body.
Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
- Not applicable / Not specified. For diagnostic reagents like the T-Tek, the "ground truth" is typically the quantitative measurement obtained from a reference method (the predicate device, STA Thrombin 10). The study focuses on comparing the output of the new device to the predicate, demonstrating analytical performance equivalence. There is no subjective interpretation by experts in the determination of a thrombin time value, unlike in imaging studies.
Adjudication Method for the Test Set:
- Not applicable. As the "ground truth" is a quantitative measurement from a comparative device, no adjudication is required or performed by human experts in the context of this study.
Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No. This type of study is typically performed for imaging devices where human readers interpret images. The T-Tek is a laboratory reagent for a quantitative blood test, so MRMC studies are not relevant.
Standalone Performance (Algorithm only without human-in-the-loop performance):
- Yes, implicitly. The device (reagent) performance is assessed independently of user influence, although qualified laboratory professionals perform the test. The "performance" refers to the reagent's analytical output. The study evaluated the reagent's performance when used "manually, or using semi-automated and automated coagulation analyzers" (described in the device description), which covers its standalone analytical capability.
Type of Ground Truth Used:
- Comparative Measurement to a Predicate Device. The "ground truth" for the performance study was the thrombin time values obtained using the STA Thrombin 10 predicate device. The study sought to demonstrate analytical equivalence, meaning the T-Tek should yield similar results to a legally marketed, established product.
Sample Size for the Training Set:
- Not applicable / Not specified. This device is a chemical reagent, not an AI or machine learning model that requires a "training set." Its formulation and performance are based on chemical properties and manufacturing, not iterative learning from data.
How the Ground Truth for the Training Set Was Established:
- Not applicable. As noted above, there is no "training set" in the context of this reagent. The "ground truth" concept is applied to the performance evaluation against the predicate device.

Summary

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Premarket Notification 510(k) T-Tek

DEC 1 2 2005

K050817

8.0 Premarket Notification 510(k) Summary [As required by section 807.92(c)]

Applicant:	Michael J. MorrisR2 Diagnostics, Inc.412 South Lafayette Blvd.South Bend, IN 46601USA
Contact:	Dr. Peggy S. CarterR2 Diagnostics, Inc.412 South Lafayette Blvd.South Bend, IN 46601TEL: (574) 288-4377FAX: (574) 288-2272
Date:	October 25, 2005
Trade Name:	R2 Diagnostics T-Tek
Common Name:	Thrombin time test
Classification Name:	Test, thrombin time(per 21 CFR section 864.7875)
Comparison Device:	STA Thrombin, K884384

Description of the Device and Intended Use

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Summary of Substantial Equivalence Comparisons

R2 Diagnostics T-Tek Thrombin Time Reagent is substantially equivalent in intended use and performance to STA Thrombin 10. Both the predicate device and the proposed product are formulated to determine thrombin time in citrated plasma. In correlation studies normal and abnormal patient plasma, as well as plasma samples from patients undergoing heparin therapy, were tested using both reagents. Comparison of data from thrombin time testing at two sites and on two different instrument types yielded correlation coefficients of r2 = 0.801 (photo-optical), slope = 0.848, intercept = 3.466 and 2 = 0.800 (mechanical), slope = 1.204, intercept = - 4.904. Within-run and between-run precision studies were also performed and CV's of less than 3% were obtained for the proposed device. CV's of less than 3% are reported for the predicate device in the manufacturers Instructions for Use.

Conclusion: Substantial Equivalence Statement

In Summary, the similar intended use, technological characteristics and the performance data provided in this premarket notification demonstrate that R2 T-Tek Thrombin Time Reagent is substantially equivalent to (Diagnostica Stago) American Bioproducts Co., STA Thrombin 10.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

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 lines representing its wings and body. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle.

Public Health Service

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

DEC 1 2 2005

Dr. Peggy S. Carter Director, Product Development R2 Diagnostics, Inc. 412 South Lafayette Blvd South Bend, IN 46601

K050817 Re: Trade/Device Name: T-Tek Regulation Number: 21 CFR 864.7875 Regulation Name: Thrombin time test Regulatory Class: Class II Product Code: GJA Dated: October 26, 2005 Received: November 1, 2004

Dear Dr. Carter:

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); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). 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.

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If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (240) 276-0484. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). 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) 443-6597 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html

Sincerely yours,

lobatz Beckerh

Robert L. Becker, Jr., MD, PH.D Director Division of Immunology and Hematology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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6.0 Indications for Use

510(k) Number (if known): _KOSOKIT

Device Name: ____T-Tek

Indications for Use:

Statement of Indications for Use

Prescription Use X (Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Page _1_of _1

(Posted November 13, 2003)

Josephine Bautista

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) K050817

Regulation Number and Section

§ 864.7875 Thrombin time test.

(a)
Identification. A thrombin time test is a device used to measure fibrinogen concentration and detect fibrin or fibrinogen split products for the evaluation of bleeding disorders.(b)
Classification. Class II (performance standards).