(108 days)
The Actalyke Activated Clotting Time System and Test Tubes are intended for use in the measurement of the activated clotting time test (ACT). Current markets using the ACT include: bypass surgery, vascular surgery, transplant surgery, renal dialysis, ECMO, cardiac catheterization and Percutaneous Transluminal Coronary Angioplasty (PTCA), Critical Care, and other medical therapies requiring heparin anticoagulation.
The Actalyke System is a portable, battery operated device designed to perform a range of whole blood coagulation tests at the patient's bedside using Activated Clotting Time (ACT) measurement techniques. Each test well of the Actalyke Instrument incorporates a highly sensitive clot detection mechanism. Operationally, the detection mechanism comprises a magnet located inside a test tube and two solid state magnetic detectors positioned within the test well - one situated at 0° and another situated at 90° with respect to the test tube. When a test tube is inserted into the test well, the detector at 0° senses the presence of the magnet as the tube slowly rotates. As clotting forms, the fibrin strands cause the magnet to rotate within the tube such that its presence is sensed by the detector at 90° (indicating the occurrence of clotting and triggering end-point detection). This two-point detection sensing system is an improvement in ACT detection methods and minimizes the possibility of a missed end-point. Each Actalyke test tube has a barcode label affixed to it, which is read by the Actalyke instrument to determine the test tube type (i.e., celite, kaolin, or glass bead), If the result is printed (optional), the normal range for the identified test tube type will be printed. The lot number and expiration date of each tube are also identified on the barcode label.
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria for the Actalyke System appear to be based on demonstrating "normal ranges" and "high correlation" with the legally marketed predicate device, the HEMOCHRON Whole Blood Coagulation System, across different test tube types (Celite, Kaolin, Glass Bead). Since specific quantitative acceptance thresholds are not explicitly stated, the reported performance is compared directly to the predicate device's performance in the provided tables.
| Test Tube Type | Acceptance Criteria (Implied) | Reported Actalyke Performance (Ranges from studies) | Predicate Device (HEMOCHRON) Performance (Ranges from studies) |
|---|---|---|---|
| Celite | Similar normal range to predicate | 108-133 seconds | 101-129 seconds |
| High correlation with predicate for varying heparin concentrations | See "Correlation with Predicate Device" tables and graphs. | See "Correlation with Predicate Device" tables and graphs. | |
| Kaolin | Similar normal range to predicate | 118-133 seconds | 108-133 seconds |
| High correlation with predicate for varying heparin concentrations | See "Correlation with Predicate Device" tables and graphs. | See "Correlation with Predicate Device" tables and graphs. | |
| Glass Bead | Similar normal range to predicate | 167-199 seconds | 145-191 seconds |
| High correlation with predicate for varying heparin concentrations | See "Correlation with Predicate Device" tables and graphs. | See "Correlation with Predicate Device" tables and graphs. |
Summary of Reported Device Performance:
- Normal Range Studies: The Actalyke System, using its own tubes, demonstrated normal ranges largely overlapping with or comparable to the Hemochron system using its own tubes, when tested on healthy patient samples (as shown in the detailed tables for Celite, Kaolin, and Glass Bead).
- Correlation Studies (with varying heparin): The Actalyke Instrument and Actalyke ACT tubes showed "high correlation" with the Hemochron Instrument and Hemochron ACT tubes across different heparin concentrations for all three tube types (Celite, Kaolin, Glass Bead), indicating similar performance in measuring coagulation time under anticoagulation. This was visually represented and stated generally as "high correlation" in the DATA SUMMARY.
2. Sample Sizes Used for the Test Set and Data Provenance
- Sample Size (Normal Range Studies):
- Celite Normal Range Study: 15 patient samples (S011-S024 excluding some, plus S002).
- Kaolin Normal Range Study: 15 patient samples (S033-S040, S004, S005, S009, S030, S031, S037, plus 11L001).
- Glass Bead Normal Range Study: 15 patient samples (S051, S027, S025, S052, S028, S019, S035, S045, 11L001, S049, S048, S006, S016, S030, S009).
- Sample Size (Correlation Studies):
- The sample size for the heparin correlation studies is not explicitly stated as a number of individual patients. However, the data represents "mean data" for varying heparin concentrations (0, 1, 3, 5 u/ml for Celite & Kaolin; 0, 0.3, 0.6, 1, 2 u/ml for Glass Bead), suggesting multiple measurements per heparin concentration. Given the normal range studies used 15 patients, it's plausible similar numbers were used for correlation, but it's not confirmed.
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). The patient IDs (e.g., S011, S002) suggest individual patient data was collected, but we cannot deduce if it was prospective or retrospective from the provided text.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
Not applicable. This device measures a physical property (clotting time) directly, rather than relying on expert interpretation of images or other qualitative data. The "ground truth" is the measured Activated Clotting Time (ACT) itself, or comparison to an established, legally marketed device (HEMOCHRON system).
4. Adjudication Method (for the test set)
Not applicable. As noted above, the device measures a physical property directly. There is no qualitative assessment or interpretation by experts that would require an adjudication method. The study design involves direct comparison of measurements between the Actalyke system and the predicate device.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This is not applicable to the Actalyke System. An MRMC study typically involves human readers interpreting cases (e.g., medical images) with and without AI assistance to assess changes in diagnostic performance. The Actalyke System is a point-of-care coagulation analyzer, not an AI-powered diagnostic imaging tool that assists human readers.
6. Standalone Performance Study
Yes, a standalone performance was done in the "Normal Range Study" for each tube type. The Actalyke instrument was used with Actalyke tubes to establish normal ranges, which were then compared to the normal ranges obtained by the Hemochron instrument with Hemochron tubes. Additionally, the correlation studies implicitly demonstrate standalone performance when the Actalyke instrument is used with Actalyke tubes across varying heparin concentrations.
7. Type of Ground Truth Used
The ground truth used is predominantly:
- Comparison to a Legally Marketed Predicate Device: The performance of the Actalyke System is evaluated by comparing its results directly to those obtained from the HEMOCHRON Whole Blood Coagulation System, which is the established standard.
- Measured Activated Clotting Time (ACT): For the normal range studies, the ACT measurements from healthy individuals define the "normal range." For the correlation studies, the measured ACT values at different heparin concentrations serve as the primary data point for comparison.
8. Sample Size for the Training Set
Not applicable. The Actalyke System does not appear to be an AI/machine learning device that requires a "training set" in the conventional sense. It is a hardware device based on magnetic detection principles. The studies described are performance validation studies, not training of an algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" for this device.
§ 864.7140 Activated whole blood clotting time tests.
(a)
Identification. An activated whole blood clotting time tests is a device, used to monitor heparin therapy for the treatment of venous thrombosis or pulmonary embolism by measuring the coagulation time of whole blood.(b)
Classification. Class II (performance standards).