HemosIL von Willebrand Factor Activity is an automated latex enhanced immunoassay intended for the in vitro diagnostic quantitative determination of von Willebrand Factor Activity (VWF Activity) in human citrated plasma on IL Coagulation Systems.

Device Description

The VWF Activity kit is a latex particle enhanced immunoturbidimetric assay to quantify VWF Activity in plasma. The activity of VWF is determined by measuring the increase of turbidity produced by the agglutination of the latex reagent. A specific anti-VWF monoclonal antibody adsorbed onto the latex reagent, directed against the platelet binding site of VWF (Glycoprotein Ib receptor), reacts with the VWF of patient plasma. The degree of agglutination is directly proportional to the activity of VWF in the sample and is determined by measuring the decrease of transmitted light caused by the aggregates.

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the HemosIL von Willebrand Factor Activity device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The submission does not explicitly state pre-defined acceptance criteria in terms of specific thresholds for correlation coefficients or precision values. Instead, it presents performance data and asserts substantial equivalence to a predicate device. We can infer that the reported performance values were considered acceptable for demonstrating substantial equivalence.

Performance Metric	Acceptance Criteria (Inferred)	Reported Device Performance
Method Comparison (vs. Predicate Device)	Strong correlation (high 'r' value), slope near 1, intercept near 0	ACL 9000:Slope: 0.832Intercept: 4.782r: 0.972
Precision (Within-run CV%)	Low variability	ACL 9000:Normal Control: 2.7%Special Test Controls Level 1: 4.6%Special Test Controls Level 2: 7.5%
Precision (Total CV%)	Low variability	ACL 9000:Normal Control: 4.9%Special Test Controls Level 1: 9.0%Special Test Controls Level 2: 8.7%

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

Sample Size (Method Comparison): 108 citrated plasma samples.
Sample Size (Precision): Not explicitly stated how many individual samples composed the "three levels of control plasma," but a single sample generated data over "multiple runs."
Data Provenance: Not explicitly stated (e.g., country of origin). The data appears to be from a prospective study conducted for the submission since it's presented as "Method Comparison studies on an ACL 9000" and "Precision... assessed over multiple runs." No indication of retrospective data.

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

Not Applicable. This device is an in-vitro diagnostic test for quantitative determination of a biomarker, not an imaging device or one requiring expert interpretation of results to establish ground truth in the traditional sense. The "ground truth" for the method comparison was the result obtained from the predicate device. For precision, the ground truth was the mean value determined by the device itself.

4. Adjudication Method for the Test Set

Not Applicable. As explained above, this type of device does not involve expert adjudication for its performance evaluation in this context. The comparison is against an established method and the device's own internal consistency.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and its effect size

No. An MRMC study is not relevant for this type of in-vitro diagnostic device. These studies typically compare human reader performance with and without AI assistance for tasks like image interpretation.

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

The performance data presented (method comparison and precision) is inherently standalone performance of the device (automated latex enhanced immunoassay) on an IL Coagulation System. There is no human-in-the-loop aspect to the VWF Activity measurement itself for interpretation or modification of results, beyond the operator loading samples and running the instrument.

7. The Type of Ground Truth Used

Method Comparison: The results obtained from the predicate device (Shield Von Willebrand Factor Activity ELISA) served as the comparative 'ground truth' or reference for assessing the new device's performance.
Precision: The mean value of the device's own measurements for control plasmas was used to assess precision (variability around that mean).

8. The Sample Size for the Training Set

Not Applicable. This device is described as an "automated latex enhanced immunoassay" which uses specific monoclonal antibodies. It is a biochemical assay and does not appear to involve machine learning or AI algorithms that require a separate "training set" of data in the typical sense. Its performance is based on the chemical reactions and optical detection, not an algorithm trained on a dataset.

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

Not Applicable. As explained above, there is no indication of a training set as would be found in AI/ML applications. The device's operational characteristics are intrinsic to its chemical and optical design.

Summary

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APR 30 2004

K040843

Section 3 HemosIL von Willebrand Factor Activity 510(k) Summary (Summary of Safety and Effectiveness)

Submitted by:

Instrumentation Laboratory Co. 113 Hartwell Avenue Lexington, MA 02421 Phone: 781-861-4467 781-861-4207 Fax:

Contact Person:

Carol Marble, Regulatory Affairs Director Phone: 781-861-4467 / Fax: 781-861-4207

Summary Prepared:

March 31, 2004

Name of the Device:

HemosIL von Willebrand Factor Activity

Regulatory Information:

Regulation Section:	Factor Deficiency Test (864.7290)
Classification:	Class II
Product Code:	GGP
Panel:	Hematology

Identification of predicate device(s):

K000398 Shield Von Willebrand Factor Activity ELISA

Description of the device/intended use(s):

Statement of Technological Characteristics of the Device Compared to Predicate Device:

HemosIL von Willebrand Factor Activity is substantially equivalent to the commercially available predicate device (Shield Von Willebrand Factor Activity ELISA) in performance and intended use.

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Section 3 (Cont.) HemosIL von Willebrand Factor Activity 510(k) Summary (Summary of Safety and Effectiveness)

Summary of Performance Data:

Method Comparison

In separate method comparison studies on an ACL 9000 (n=108) using citrated plasma samples ranging from 0 to 192% VWF activity, the correlation statistics for HemosIL von Willebrand Factor Activity versus the predicate device are shown below:

IL System	% VWF ActivitySlope	Intercept	r
ACL 9000	0.832	4.782	0.972

Precision

Within run and total precision assessed over multiple runs using both three levels of control plasma gave the following results:

ACL 9000:	Mean (% VWF Activity)	CV% (Within run)	CV% (Total)
Normal Control	79.6	2.7	4.9
Special Test Controls Level 1	49.8	4.6	9.0
Special Test Controls Level 2	27.7	7.5	8.7

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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 features a stylized eagle with three stripes representing the three levels of government: federal, state, and local. The eagle is encircled by the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" in a circular arrangement.

Public Health Service

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

APR 3 0 2004

Ms. Carol Marble Director, Regulatory Affairs Instrumentation Labortory Co. 113 Hartwell Avenue Lexington, MA 02421

Re: K040843

Trade/Device Name: HemosIL von Willebrand Factor Activity Regulation Name: Factor deficiency test Regulation Number: 21 CFR 864.7290 Regulatory Class: Class II Product Code: GGP Dated: March 31, 2004 Received: April 1, 2004

Dear Ms. Marble:

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).

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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 (301) 594-3084. 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/dsma/dsmamain.html.

Sincerely yours,

Joseph L. Arblett

Joseph L. Hackett, Ph.D. Acting Director Division of Immunology and Hematology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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Indications for Use Statement

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name: HemosIL von Willebrand Factor Activity

Indications for Use:

HemosIL von Willebrand Factor Activity is an in vitro diagnostic automated latex enhanced immunoassay intended for the quantitative determination of von Willebrand Factor Activity (VWF Activity) in human citrated plasma on IL Coagulation Systems by immunoturbidity.

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Concurrence of CDRH, Office of Device Evaluation (ODE)
signature
Division Sign-Off
Office of In Vitro Diagnostic Device Evaluation and Safety

510(k)	K040843
Prescription Use (Per 21 CFR 801.019)	OR Over-The-Counter Use

Regulation Number and Section

§ 864.7290 Factor deficiency test.

(a)
Identification. A factor deficiency test is a device used to diagnose specific coagulation defects, to monitor certain types of therapy, to detect coagulation inhibitors, and to detect a carrier state (a person carrying both a recessive gene for a coagulation factor deficiency such as hemophilia and the corresponding normal gene).(b)
Classification. Class II (performance standards).