(161 days)
The CoaguChek Pro APTT test is for the quantitative determination of the activated partical thromboplastin time (APTT) of freshly drawn whole blood. It is intended for health care professional use only.
The APTT is used to evaluate intrinsic pathway function. The APTT is sensitive to deficiencies of factors VIII, IX, XI, and XII, prekallikrein, high molecular weight kinogen, as well as common pathway factors (II, V, X, and fibrinogen). The APTT is useful as a screening test for coagulation function, since it is sensitive to all coagulation factors except VII, platelet factor III and calcium. Additionally, the APTT is used to monitor the effectiveness of heparin therapy. Many diseases and drugs can prolong or prevent coagulation by altering the balance of clotting factors involved in coagulation. The APTT test is initiated by inserting a CoaguChek Pro APTT test cartridge into the instrument. The instrument reads a code on the test cartridge to determine test identity and lot number. The test cartridge contains a sample application well, a reagent chamber, and a reaction path. After the instrument heats the test cartridge, a drop of fresh, whole blood is placed on the test cartridge sample application well. Blood is drawn into the reagent chamber by capillary action, where it mixes with the reagent to initiate coagulation. The blood sample moves along the reaction path until a clot forms. The laser optical system detects the clot by monitoring blood flow; endpoint is reached when the blood stops moving. The time from sample application to clot detection is the APTT. The displayed result is equivalent to laboratory plasma APTT results. Because each newly-manufactured lot is calibrated to an internal reference lot, any lot-to-lot variability between reagents is corrected electronically using information coded on the lot-specific code key.
The medical device in question is the CoaguChek Pro System, APTT Test and Controls.
1. Table of Acceptance Criteria and Reported Device Performance
| Claim | CoaguChek Plus APTT Test (Predicate) | CoaguChek Pro APTT Test |
|---|---|---|
| Mean Normal | 31 seconds | 31 seconds |
| Verified Assay Range | 18 - 150 seconds | 18 - 150 seconds |
| Displayed Assay Range | 18 - 150 seconds | 18 - 150 seconds |
| Factor Sensitivity | Factors VIII, IX, XI, XII, prekallikrein, and kininogen | Factors VIII, IX, XI, XII, prekallikrein, and kininogen |
| Verified Hematocrit Range | 25.5% - 53% | 26.5% - 53% |
| Precision with controls | Control Mean CV | |
| Within-Day: | ||
| Level 1: 55.5 sec 4.7% | ||
| Level 2: 116.1 sec 4.5% | ||
| Between-Day: | ||
| Level 1: 56.2 sec 5.8% | ||
| Level 2: 116.8 sec 3.8% | Control Mean CV | |
| Overall: | ||
| Level 1: 44.2 sec 5.3% | ||
| Level 2: 83.4 sec 4.7% | ||
| Accuracy (Regression Analysis) | Center A, n = 73: y = 1.24x - 9.9, r = 0.78 | |
| Center B, n = 71: y = 1.54x - 22.5, r = 0.87 | ||
| Center C, n = 59: (data truncated) | Site 1, n = 55: y = 0.792x + 8.5, r = 0.89 | |
| Site 2, n = 54: y = 1.134x - 0.8, r = 0.93 | ||
| Site 3, n = 45: (data truncated) |
Note: The provided document does not explicitly state "acceptance criteria" but rather presents a comparison of performance characteristics between the new device (CoaguChek Pro) and its predicate (CoaguChek Plus). The implication is that the CoaguChek Pro's performance characteristics demonstrate substantial equivalence to the predicate device, thereby meeting the necessary criteria for market entry. The study aims to show that the CoaguChek Pro's performance is comparable to or acceptable relative to the already marketed CoaguChek Plus system.
2. Sample size used for the test set and the data provenance
The sample sizes for the accuracy study (which serves as the "test set" for this type of device comparison) are:
- Site 1: n = 55
- Site 2: n = 54
- Site 3: n = 45
The total number of samples for the accuracy study in the CoaguChek Pro is 55 + 54 + 45 = 154 samples.
The document does not explicitly state the country of origin of the data or whether it was retrospective or prospective. However, given the nature of a 510(k) submission for a diagnostic device, these studies are typically prospective clinical performance evaluations conducted in a controlled environment, likely in the United States, by the manufacturer or affiliated research sites.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This type of in vitro diagnostic device (APTT test) typically uses a laboratory reference method or a legally marketed predicate device's results as the "ground truth" for comparison, rather than expert interpretation of images or clinical findings.
The document states: "The displayed result is equivalent to laboratory plasma APTT results." and "Test results for both methods were originally calibrated to laboratory plasma method." This indicates that the ground truth for the reported accuracy data would be a standard laboratory plasma APTT method.
Therefore, the concept of "experts" in the sense of clinicians or radiologists establishing ground truth is not directly applicable here. The ground truth is established by the highly controlled and validated laboratory reference methods for APTT, which are operated by trained laboratory professionals. The document does not specify the number or qualifications of the lab personnel operating the reference method.
4. Adjudication method for the test set
No adjudication method is mentioned. For an in vitro diagnostic device comparing its results to a laboratory reference method, an adjudication process involving multiple human readers or experts is generally not relevant. The comparison is typically a direct quantitative assessment (e.g., correlation and regression analysis) between the device's numerical output and the reference method's numerical output.
5. If a multi-reader, multi-case (MRMC) comparative effectiveness study was done, and the effect size of how much human readers improve with AI vs without AI assistance
No, an MRMC comparative effectiveness study was not done.
This document describes an in vitro diagnostic device for measuring Activated Partial Thromboplastin Time (APTT) in whole blood, not an AI-assisted diagnostic imaging or clinical decision support system. Therefore, the concept of human readers improving with AI assistance is not applicable. The device provides a quantitative measurement directly.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, the performance presented is standalone/algorithm-only.
The CoaguChek Pro System provides a direct, quantitative measurement of APTT. The performance characteristics (Mean Normal, Assay Range, Factor Sensitivity, Hematocrit Range, Precision, Accuracy) describe the device's inherent analytical performance without direct human interpretation of the result in the clinical decision-making process for the purpose of the measurement itself. Healthcare professionals use the results provided by the device, but the device's detection of clot formation and calculation of APTT is an automated, standalone function.
7. The type of ground truth used
The ground truth used for performance validation is the laboratory plasma APTT method. The document explicitly states: "The displayed result is equivalent to laboratory plasma APTT results. Because each newly-manufactured lot is calibrated to an internal reference lot, any lot-to-lot variability between reagents is corrected electronically using information coded on the lot-specific code key." And "Test results for both methods [CoaguChek Pro and CoaguChek Plus] were originally calibrated to laboratory plasma method."
8. The sample size for the training set
The document does not explicitly specify a "training set" sample size. For an in vitro diagnostic device like this, the "training" equivalent would be the development and calibration of the instrument and reagents. While there's no mention of a traditional machine learning "training set," the device's internal reference lots and calibration processes are essentially what "train" the system to provide accurate results. The "Accuracy" and "Precision" data presented are considered the validation or test data, comparing the device's performance to the predicate and/or reference method.
9. How the ground truth for the training set was established
As noted above, the concept of a "training set" in the context of this device is analogous to its development and calibration. The ground truth for this process, as indicated by the text, is the laboratory plasma APTT method. The device's results are intended to be "equivalent to laboratory plasma APTT results" and were "originally calibrated to laboratory plasma method." This implies that the standard laboratory method was used as the reference to establish the correct readings and ensure lot-to-lot variability is corrected electronically.
§ 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.