HemosIL Silica Clotting Time is intended for the detection of Lupus Anticoagulants in human citrated plasma on the IL Coagulation Systems by the use of screening (SCT Screen) and confirmatory (SCT Confirm) reagents sensitized to phospholipid dependent antibodies. For in vitro diagnostic use.

Device Description

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the HemosIL Silica Clotting Time device, based on the provided text:

Acceptance Criteria and Device Performance

Acceptance Criteria Category	Specific Acceptance Criteria (Implied by Predicate Equivalence)	Reported Device Performance (HemosIL Silica Clotting Time)
Method Correlation	Substantially equivalent correlation to predicate devices (HemosIL LAC Screen and HemosIL LAC Confirm)	Slope: 1.099 Intercept: -0.086 r (correlation coefficient): 0.874
Clinical Performance (Cut-off ≥ 1.20 for predicate)	Substantially equivalent diagnostic accuracy to predicate devices	Relative Sensitivity: 92.4% (95% C.I. = 82.1-97.0) Relative Specificity: 100% (95% C.I. = 97.6-100.0)
Precision (Within Run)	Acceptable within-run variability	Normal Control: 2.47% CV Low LA Control: 4.05% CV High LA Control: 5.24% CV
Precision (Total)	Acceptable total variability	Normal Control: 2.95% CV Low LA Control: 6.00% CV High LA Control: 5.60% CV

Note: The document explicitly states that the device "is substantially equivalent to the commercially available predicate devices (HemosIL LAC Screen and HemosIL LAC Confirm) in performance and intended use." This implies that the acceptance criteria were based on demonstrating comparable performance to these predicate devices rather than pre-defined absolute thresholds, for the correlation and clinical performance metrics. For precision, the reported %CVs fall within generally acceptable ranges for diagnostic assays.

Study Details

Sample size used for the test set and the data provenance:
- Method Comparison Study: 210 citrated plasma samples (120 normals/90 abnormals)
- Clinical Study: 206 citrated plasma samples (121 normals/85 abnormals)
- Data Provenance: "in-house study" and "clinical study." The document does not specify the country of origin, but given the manufacturer (Lexington, MA, USA) and the 510(k) submission to the FDA, it is highly probable the studies were conducted within the US or followed US regulatory guidelines. The studies appear to be retrospective as they involved analyzing collected plasma samples.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not explicitly state the number or qualifications of experts used to establish the ground truth for the test set. The ground truth appears to be based on the results from the predicate devices (HemosIL LAC Screen and HemosIL LAC Confirm) for comparison. The classification of samples as "normals" and "abnormals" for Lupus Anticoagulants would have been based on established clinical diagnostic criteria, likely involving expert interpretation of multiple tests, but this detail is not provided.
Adjudication method for the test set:
- The document does not describe a specific adjudication method. As the primary comparison is against predicate devices, the "ground truth" for the test set is established by the results of those predicate devices.
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) assay, not an AI-assisted imaging or diagnostic tool that requires human reader interpretation. Therefore, an MRMC study is not applicable.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes. The reported performance metrics (slope, intercept, r, sensitivity, specificity, precision) are for the HemosIL Silica Clotting Time device running on an IL Coagulation System, indicating a standalone (algorithm/device only) performance evaluation. There is no mention of human-in-the-loop performance.
The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The ground truth for the test sets (both method comparison and clinical) appears to be established by the results obtained from the predicate devices (HemosIL LAC Screen and HemosIL LAC Confirm). Additionally, for the clinical study, it's mentioned that "All known Lupus Anticoagulant samples (n=48) tested as part of this study gave SCT normalized ratios > 1.24," suggesting that a subset of the abnormal samples had a pre-established clinical diagnosis of Lupus Anticoagulant, likely based on a combination of tests and expert consensus.
The sample size for the training set:
- The document does not specify a separate "training set" in the context of machine learning. This is an IVD device, and the development process would involve formulation, optimization, and characterization rather than AI model training. The "in-house study" and "clinical study" are performance validation studies.
How the ground truth for the training set was established:
- Not applicable as there is no mention of a separate training set in the context of an AI/ML model for this IVD device. The development of such a device focuses on reagent formulation and instrument calibration, typically using well-characterized samples and reference methods.

Summary

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Section 3 HemosIL Silica Clotting Time - 510(k) Summary (Summary of Safety and Effectiveness)

Submitted by:

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

Contact Person:

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

Summary Prepared:

January 28, 2005

Name of the Device:

HemosIL Silica Clotting Time

Regulatory Information:

Regulation Section: Partial Thromboplastin Time Tests (864.7925) Classification: Class II Product Code: GFO Panel: Hematology

Identification of Predicate Device(s):

K990302 HemosIL LAC Screen and HemosIL LAC Confirm

Description of the Device/Intended Use(s):

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

The HemosIL Silica Clotting Time is substantially equivalent to the commercially available predicate devices (HemosIL LAC Screen and HemosIL LAC Confirm) in performance and intended use.

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Section 3 HemosIL Silica Clotting Time - 510(k) Summary (Summary of Safety and Effectiveness)

Summary of Performance Data:

Method Comparison

In an in-house study of 210 citrated plasma samples (120 normals/90 abnormals) on an ACL Advance, comparing HemosIL Silica Clotting Time to the predicate devices, the following correlation data were obtained:

Unit	slope	intercept	r	Reference method
NormalizedLAC ratio	1.099	-0.086	0.874	LAC Screen/Confirm

In a clinical study of 206 citrated plasma samples (121 normals/85 abnormals), comparing HemosIL Silica Clotting Time (cut-off > 1.24) to the predicate devices (cut-off ≥ 1.20) on an ACL Futura, a relative Sensitivity of 92.4% (95% C.I. = 82.1-97.0) and a relative Specificity of 100% (95% C.I. = 97.6-100.0) were determined. All known Lupus Anticoagulant samples (n=48) tested as part of this study gave SCT normalized ratios > 1.24.

Within Run Precision

Within run and between run precision was assessed over multiple runs (n=80) using three levels of controls.

Instrument	Control	MeanNormalized Ratio	Within run%CV	Total%CV
ACL Advance	Normal Control	1.05	2.47	2.95
ACL Advance	Low LA Control	1.90	4.05	6.00
ACL Advance	High LA Control	2.77	5.24	5.60

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Image /page/2/Picture/1 description: The image is a black and white logo for the Department of Health & Human Services - USA. The logo is circular in shape, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter of the circle. In the center of the circle is an abstract symbol that resembles an eagle or other bird in flight. The symbol is composed of several curved lines that create the impression of feathers or wings.

MAR 3 0 2005

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

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

Re: K050221

Trade/Device Name: HemosIL Silica Clotting Time Regulation Number: 21 CFR 864.7925 Regulation Name: Partial thromboplastin time tests Regulatory Class: Class II Product Code: GFO Dated: January 28, 2005 Received: January 31, 2005

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. Iisting of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adultcration.

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 (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,

Robert Beckerh

Robert L. Becker, Jr., MD, I 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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Indications for Use Statement

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name: HemosIL Silica Clotting Time

Indications for Use:

For in vitro diagnostic use.

Prescription Use
(Part 21 CFR 801 Subpart D)

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 In Vitro Diagnostic Devices (OIVD)

Josephine Bautista
Division Sign Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) K050221

Regulation Number and Section

§ 864.7925 Partial thromboplastin time tests.

(a)
Identification. A partial thromboplastin time test is a device used for primary screening for coagulation abnormalities, for evaluation of the effect of therapy on procoagulant disorders, and as an assay for coagulation factor deficiencies of the intrinsic coagulation pathway.(b)
Classification. Class II (performance standards).