The Amelung KC 4 A Micro Coagulation Analyzer is a semi-automated mechanical clot detection system designed for the determination of prothrombin times (PT), activated partial thromboplastin times (APTT), fibrinogen concentrations and other clotting tests. Any clotting time test that has fibrin formation as its endpoint may be performed on the KC 4 A.

Device Description

AI/ML Overview

The provided text describes performance testing for the Amelung KC 4 A Micro Coagulation Analyzer, a semi-automated mechanical clot detection system. However, specific acceptance criteria are not explicitly stated in a defined table or section. Instead, the study aims to demonstrate substantial equivalence to predicate devices and acceptable precision.

Here's an analysis of the available information:

1. Table of "Acceptance Criteria" and Reported Device Performance

Since explicit acceptance criteria are not provided, I will interpret "acceptable limits" for precision and strong correlation coefficients for method comparison as the implied criteria for substantial equivalence.

Performance Metric	Implied Acceptance Criterion (Inferred)	Reported Device Performance	Comments
Method Comparison (Correlation with Reference/Predicate Devices)	Correlation coefficient (r) close to 1, and regression equation (y = mx + b) where m is close to 1 and b is close to 0 (indicating good agreement)	See detailed results below	The reported `r` values are generally high, indicating strong correlation.
Precision	"Within acceptable limits" (for beta sites); Coefficient of Variation (CV) < 9% (for in-house studies)	Beta Sites: "Results were within acceptable limits." In-house: CV < 9% for all studies.	This indicates good reproducibility of results by the device.

Detailed Method Comparison Performance:

Beta Site Studies (Comparison with Sigma Diagnostics Reference Lab):

Site #	Assay	Reported r	Reported Regression Equation
#1	PT	0.991	y = 0.981x + 0.492
#1	APTT	0.960	y = 1.066x + 0.379
#2	PT	0.989	y = 1.019x - 0.248
#2	APTT	0.965	y = 1.029x + 1.021
#3	PT	0.974	y = 1.012x + 0.326
#3	APTT	0.927	y = 0.786x + 9.470

In-house Studies (Comparison with Fibrometer and CA-5000 Predicate Devices):

Assay	Predicate Device (Implied)	Reported r	Reported Regression Equation
PT	Fibrometer	0.988	y = 1.051x - 0.241
APTT	Fibrometer	0.896	y = 1.235x + 0.873
Fibrinogen	CA-5000	0.930	y = 1.067x + 30.749
Factor IX	CA-5000	0.897	y = 0.958x - 3.403
Factor X	CA-5000	0.974	y = 1.010x - 0.166

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

Beta Sites (Method Comparison): "more than 45 samples" for PT and APTT assays.
- Provenance: Data was collected from three physician office laboratories (POLs) and compared to a reference laboratory (Sigma Diagnostics). This implies prospective collection from real-world clinical settings, likely within the United States given the Sigma Diagnostics address.
In-house Studies (Method Comparison): "more than one hundred samples" for PT and APTT. Additional assays (Fibrinogen, Factor IX, Factor X) were also performed but their explicit sample size isn't separately stated, likely falling under the "more than one hundred samples" umbrella for in-house testing.
- Provenance: "In-house performance studies," suggesting data collected at the manufacturer's facility, likely mimicking clinical samples.

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

The concept of "experts" to establish ground truth as typically understood for AI/diagnostic imaging devices (e.g., radiologists interpreting images) does not directly apply here. For this type of coagulation analyzer, the "ground truth" or reference values are established by:

Reference Laboratory: Sigma Diagnostics acted as the reference laboratory in the beta site studies. Their methods and results were considered the standard against which the KC 4 A was compared. The qualifications of the personnel at Sigma Diagnostics are not specified, but they would typically involve trained medical technologists or clinical laboratory scientists proficient in coagulation testing.
Predicate Devices: The Fibrometer and CA-5000 were used as predicate devices in the in-house studies. The results from these established and legally marketed devices served as the "ground truth" for comparison.

There isn't a stated number of individual "experts" establishing ground truth through consensus, as would be common in qualitative diagnostic assessments.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1, 3+1 for consensus readings) are typically used when there's subjective interpretation of qualitative results (e.g., image reading). For quantitative measurements like coagulation times, adjudication in this manner is not relevant. The comparison is made between the numerical output of the test device and the numerical output of the reference/predicate device. Any discrepancies would be analyzed statistically rather than by panel consensus.

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

This section is not applicable to the provided study.

The Amelung KC 4 A Micro Coagulation Analyzer is a device for performing laboratory tests, not an AI-powered diagnostic tool for human reader improvement.
The study focuses on the analytical performance of the device itself (accuracy, precision) compared to other devices or a reference lab, not on the impact of AI assistance on human readers.

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

This section is applicable as it describes the standalone performance of the device. The entire study described focuses on the standalone performance of the KC 4 A Micro Coagulation Analyzer, without human intervention in the result generation beyond operating the semi-automated system.

The correlation coefficients and regression equations presented demonstrate how well the KC 4 A's measurements align with those from established methods (reference lab or predicate devices) when operating independently.
Precision studies also evaluate the inherent variability of the device itself.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The ground truth used in this study is based on:

Reference Laboratory Testing: For the beta site studies, the results obtained from Sigma Diagnostics served as the reference standard.
Predicate Device Results: For the in-house studies, the results generated by the Fibrometer (for PT and APTT) and the CA-5000 (for Fibrinogen, Factor IX, Factor X) were considered the ground truth. These are established, validated devices whose outputs are accepted clinical measures.

This is essentially a method comparison study where the new device's performance is gauged against established clinical laboratory methods.

8. The Sample Size for the Training Set

This study describes performance validation testing, not an AI model development process. Therefore, there is no explicit "training set" as would be defined for machine learning. The device itself is a mechanical and optical system, not an algorithm that "learns" from data.

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

As there is no "training set" in the context of AI for this device, this question is not applicable. The device's operational parameters and calibration would be established through engineering design and standard laboratory calibration procedures using known controls, not through a data-driven training process with established ground truth.

Summary

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510(k) NOTIFICATION

Sigma Diagnostics 545 South Ewing Avenue St. Louis, MO 63103

KC 4 A Micro Coagulation Analyzer December 15, 1995

KG5535

12/11/2000

ATTACHMENT 1

Summary of Safety and Effectiveness

{1}------------------------------------------------

510(k) NOTIFICATION

KC 4 A Micro Coagulation Analyzer December 15, 1995

ATTACHMENT 1

510(k) Summary of Safety and Effectiveness

In beta sites performance studies, three physician office laboratories (POL) analyzed more than 45 samples using the KC 4 A. Split samples from the same specimens were also analyzed using the KC 4 A at Sigma Diagnostics, the study's reference laboratory. PT and APTT assays were performed at all sites. The correlation coefficient and the regression equation for these comparisons were as follows:

Site #1:	PT:	r = 0.991	y = 0.981x + 0.492
	APTT:	r = 0.960	y = 1.066x + 0.379
Site #2:	PT:	r = 0.989	y = 1.019x - 0.248
	APTT:	r = 0.965	y = 1.029x + 1.021
Site #3:	PT:	r = 0.974	y = 1.012x + 0.326
	APTT:	r = 0.927	y = 0.786x + 9.470

Precision studies were also performed at all sites. Results were within acceptable limits.

In in-house performance studies. PT and APTT were performed on more than one hundred samples using both the KC 4 A and the Fibrometer. The CA-5000 was used as the predicate device for Fibrinogen, Factor IX, and Factor X assays. The correlation coefficient and the regression equation were as follows:

PT:	r = 0.988	$y = 1.051x - 0.241$
APTT:	r = 0.896	$y = 1.235x + 0.873$
Fibrinogen:	r = 0.930	$y = 1.067x + 30.749$
Factor IX:	r = 0.897	$y = 0.958x - 3.403$
Factor X:	r = 0.974	$y = 1.010x - 0.166$

Precision studies were performed in-house. The coefficient of variation (CV) for all studies was less than 9%.

These data clearly demonstrate that the performance of the KC 4 A Micro Coagulation Analyzer is substantially equivalent to the performance of the predicate device.

Regulation Number and Section

§ 864.5425 Multipurpose system for in vitro coagulation studies.

(a)
Identification. A multipurpose system for in vitro coagulation studies is a device consisting of one automated or semiautomated instrument and its associated reagents and controls. The system is used to perform a series of coagulation studies and coagulation factor assays.(b)
Classification. Class II (special controls). A control intended for use with a multipurpose system for in vitro coagulation studies is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.