The VFE assay is an in vitro enzyme immunoassay for quantifying the concentration of von Willebrand Factor Antigen in human plasma to aid in differentiating patients with von Willebrand disease from those with Classical Hemophilia A.

Device Description

VFE is an enzyme immunoassay, in microplate format, intended for the in vitro quantification of von Willebrand Factor antigen in serum or plasma as an aid to differentiate patients with von Willebrand disease from those with classical Hemophilia A. This assay represents an updated technical format, with performance improvements, when compared to the predicate device.

AI/ML Overview

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

Device: VFE (von Willebrand Factor Antigen Assay)

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state "acceptance criteria" but rather presents a comparison to a predicate device (SPECTRO vWF) to demonstrate "substantial equivalence." The performance parameters of the VFE are compared to those of the predicate. We can infer that the VFE's performance should be comparable to or better than the predicate's for "substantial equivalence."

Parameter	Acceptance Criteria (Inferred from Predicate)	Reported Device Performance (VFE)
Sensitivity	Comparable to 0.23% N	0.78% N
Intra-assay reproducibility - CV	Comparable to 6.2 - 8.0	5.0 - 5.8
Inter-assay reproducibility - CV	Comparable to 6.3 - 12.8	7.0 - 11.5
Accuracy - R (compared to predicate test results)	N/A (predicate compared to Laurell Rocket)	0.849 (n=118)

Note on Sensitivity: The VFE's reported sensitivity (0.78% N) is higher than SPECTRO vWF's (0.23% N). In this context, a higher percentage might indicate a detection limit, where a lower percentage is generally better for sensitivity in an assay (meaning it can detect lower concentrations). However, without further context on the specific units and definition of "% N," it's difficult to definitively say if VFE is "better" or if it represents a different measure. The conclusion statement indicates "similar characteristics," suggesting this difference was not considered a deal-breaker for substantial equivalence.

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

Sample Size for Accuracy (compared to predicate): 118 samples (n = 118)
Data Provenance: Not explicitly stated. The comparison is made to a predicate test, "SPECTRO vWF," which is also from Ramco Laboratories, Inc. No information regarding the country of origin or whether the data was retrospective or prospective is provided.

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

This information is not provided in the document. The accuracy of the VFE is compared to results from the predicate device, and the predicate's accuracy was "original comparison versus Laurell Rocket electrophoresis results." There is no mention of experts establishing a ground truth.

4. Adjudication Method for the Test Set

This information is not provided. The comparison is statistical (R value) against a predicate device's results.

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. This device is an in vitro diagnostic (IVD) enzyme immunoassay, not an AI-powered diagnostic imaging device. Therefore, an MRMC study with human readers and AI assistance is not applicable.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, implicitly. The performance data presented (sensitivity, reproducibility, accuracy) represents the standalone performance of the VFE assay itself, without human interpretation in the sense of a "human-in-the-loop" for image or complex data analysis. The assay produces a quantitative result.

7. The Type of Ground Truth Used

For the VFE's accuracy, the ground truth was the results obtained from the predicate device (SPECTRO vWF).
For the predicate device's original accuracy, the ground truth was derived from Laurell Rocket electrophoresis results.

8. The Sample Size for the Training Set

This information is not applicable/not provided. The VFE is an enzyme immunoassay, not a machine learning model that requires a "training set" in the conventional sense. The "training" of an assay involves optimization during development, but specific sample sizes for such an activity are not documented in the same way as for AI models.

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

Not applicable/not provided. As mentioned above, this is an immunoassay, not an AI model.

Summary

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OCT 22 1998

Image /page/0/Picture/1 description: The image shows the logo for Ramco Laboratories Inc. The logo is in black and white and features the company name in a bold, sans-serif font. The address "4507 Mt. Vernon St." is printed in a smaller font below the company name.

07 Mt. Vernon • Houston, Texas 77006 • (713) 526-9677 • Toll Free Number 1-800-231-6238 24 hrs. Fax No.: 713-526-1528

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 Premarket Notification [510(k)] Number is:_______________________________________________________________________________________________________________________

Submitter:	Ramco Laboratories, Inc.4507 Mt. VernonHouston, Texas 77006
Phone #:Fax #:	(713) 526-9677(713) 526-1528
Contact Person:	Jeffrey B. Grubb, President
Dated Prepared:	September 3, 1998
Device Name:	von Willebrand Factor Antigen Assay
Trade Name:	VFE
Common Name:	Enzyme Assay for von Willebrand Facto r
Classification Name:	Enzyme Linked Immunoassay
Predicate Device Name:	SPECTRO vWFRamco Laboratories, Inc.4507 Mt. VernonHouston, Texas 77006510(k) #K861159

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Description of Device:

This assay represents an updated technical format, with performance improvements, when compared to the predicate device.

Intended Use and Indications for Use:

VFE is intended for use as an aid in the diagnosis and management of patients having an increased tendency to bleed. It is useful to differentiate patients with von Willebrand disease from those with Classical Hemophilia A (Factor VIII coagulant deficiency). The later group of patients have prolonged activated partial thromboplastin time (PTT) but have normal or increased concentrations of von Willebrand Factor (vWF) in their plasma. In contrast, patients with von Willebrand disease have depressed levels of vWF.

VFE should be used whenever a patient demonstrates:

a decrease in procoagulant activity as measured by activated PTT; and/or i)
ii) a prolonged bleeding time.

	VFE	SPECTRO vWF
Methodology	Sandwich ELISA	Sandwich ELISA
Solid phase	coated microtiterwells	coated beads
Material	polystyrene	polystyrene
Antibody	rabbit anti-humanvWF, IgG from(NH4)2SO4	rabbit anti-humanvWF, IgG from(NH4)2SO4
Conjugate	HRP labeled anti-human vWF antibodyLabeled anti-human vWF	Alkalinephosphatase
Antibody	sheep	rabbit

Summary of Technological Characteristics of Predicate and Proposed Device

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Sample Material	serum, plasma inEDTA or citrate	plasma inEDTA or citrate
Sample dilution	1:51 and 1:102 ifNeeded	1:51
Sample volume	20 microliters10 microliters if needed	50 microliters;
Incubations	2	2
Length #1	2 hours, 10 min.	2 hours
Length #2	30 minutes	30 minutes
Washes	4	as needed
Wash material	1X diluted washBuffer	deionized water
Calibrator	Lyophilized, pre-dilutedhuman plasma pool	liquid purified humanvWF in buffer
Number	5 dilutions per assay	one per assay
Assay Reading	microplate reader	spectrophotometer
Wavelength	450 nm	492 nm
Backgroundcorrection	yes	no
Substrate	TMB	phenylphosphatedisodium, 4-amino-tipyrine
Components/kit	1	2
Color developer	none	potassium ferricyanide
Stop Solution	1% HCl	none

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Non-clinical Performance Discussion:

The following non-clinical performance data comparison indicates that SPECTRO vWF, the predicate test, and VFE have similar characteristics and are substantially equivalent.

Parameter	VFE	SPECTRO vWF
Sensitivity	0.78% N	0.23% N
Intra-assayreproducibility - CV	5.0 - 5.8	6.2 - 8.0
Inter-assayreproducibility - CV	7.0 - 11.5	6.3 - 12.8
Accuracy - R	0.849*(n = 118)	0.96**(n = 24)

compared to predicate test results

**original comparison versus Laurell Rocket electrophoresis results

Conclusions from Non-clinical Testing:

Based on the above results the performance characteristics of, VFE, the subject device, and SPECTRO vWF, are substantially equivalent. Since two tests have very similar technological characteristics, this conclusion is not unexpected.

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Image /page/4/Picture/11 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized caduceus symbol, which features a staff with a serpent entwined around it. The logo is surrounded by the text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" in a circular arrangement. The text is in all caps and is evenly spaced around the caduceus symbol.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

OCT 2 2 1998

Mr. Jeffrey B. Grubb President Ramco Laboratories, Inc. 4507 Mt. Vernon Houston, Texas 77006

Re: K983107 Trade Name: VFE Regulatory Class: II Product Code: GGP Dated: September 3, 1998 Received: September 4, 1998

Dear Mr. Grubb:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we 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). 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 (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 A substantially equivalent determination assumes compliance to 895. with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Requlation (QS) for Medical Devices: General requlation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such Failure to comply with the GMP regulation may result in assumptions. regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

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This letter will allow you to begin marketing your device as described in your 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 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. 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"(21 CFR 807.97). Other qeneral information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers 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,

Steven Putman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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INDICATIONS FOR USE STATEMENT

510(k) Number: K983107

Device Name: VEE

The VFE assay is an in vitro enzyme immunoassay Indications for Use: for quantifying the concentration of von Willebrand Factor Antigen in human plasma to aid in differentiating patients with von Willebrand disease from those with Classical Hemophilia A.
(PLEASE DO NOT WRITE BELOW THIS LINE – CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)
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	(Division Sign-Off) Division of Clinical Laboratory Devices
510(k) Number	K983107

Prescription Use	✓	OR	Over-The-Counter
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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).