(60 days)
The HEMOCHRON® Electronic System Verification Tube is intended for in vitro diagnostic use in performing a quantitative electronic detection system verification of HEMOCHRON® Coagulation Instruments. The Electronic System Verification Tube electronically simulates test initiation and clot detection in the same manner as patient assay end points are recorded.
The device is a plastic tube with battery operated electronic circuitry that electronically simulate test initiation and clot detection using the same principles employed in a clotting time assay. Once started and placed in the Hemochron test well, the ESVT electronically simulates the operation of a 100, 300 and 500 second clotting time.
The comparison of the displayed Hemochron clotting time with the ESVT clotting time is a quality control test of the functionality of the test well and test detector.
The HEMOCHRON® Electronic System Verification Tube (ESVT) is an in vitro diagnostic device used for quantitative electronic detection system verification of HEMOCHRON® Coagulation Instruments. It electronically simulates test initiation and clot detection to check the timing capability and well rotation of HEMOCHRON instruments.
Here's a breakdown of the acceptance criteria and the study that demonstrates the device meets these criteria:
1. Acceptance Criteria and Reported Device Performance
| Control | Acceptable Range | Reported Mean | Reported Standard Deviation (SD) | Reported Coefficient of Variation (CV%) |
|---|---|---|---|---|
| Normal level | 90-110 seconds | 97.56 seconds | 2.67 | 2.74% |
| Abnormal level I | 290-310 seconds | 297.3 seconds | 3.03 | 1.02% |
| Abnormal Level II | 490-510 seconds | 497.6 seconds | 3.11 | 0.63% |
Analysis:
The reported mean values for all three control levels (Normal, Abnormal I, and Abnormal II) fall within their respective acceptable ranges. The low Standard Deviation and Coefficient of Variation percentages indicate high precision and reproducibility of the device's performance across different operators and days.
2. Sample Size and Data Provenance for Test Set
- Sample Size for Test Set: For each of the three control levels (Normal, Abnormal I, Abnormal II), the sample size (N) was 120. This means 120 measurements were taken for each level.
- Data Provenance: The study was conducted by International Technidyne Corp., located in Edison, NJ, USA. The data is prospective, as it was generated specifically for the purpose of demonstrating the device's performance and supporting its 510(k) submission. There is no indication of retrospective data use.
3. Number of Experts and Qualifications for Ground Truth
The provided document describes a precision study for the HEMOCHRON® ESVT, not a study involving interpretation by human experts to establish ground truth for clinical outcomes or diagnoses. The "ground truth" in this context is the pre-defined ideal timing ranges for the electronic simulations, which are a characteristic of the device itself and its internal electronic circuitry.
Therefore:
- Number of Experts: Not applicable.
- Qualifications of Experts: Not applicable.
4. Adjudication Method for the Test Set
Since this is a precision study of an electronic device's timing accuracy against pre-defined electronic simulation ranges, there was no need for human adjudication of results in the traditional sense (e.g., for diagnostic discrepancies). The device's output (clotting time) was compared directly to the electronically simulated time.
Therefore:
- Adjudication method: Not applicable.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted and is not relevant for this device. The HEMOCHRON® ESVT is an electronic quality control device, not a diagnostic aid requiring human interpretation of clinical cases. Its purpose is to verify the functionality of a coagulation instrument, not to assist humans in making clinical diagnoses.
6. Standalone (Algorithm Only) Performance Study
Yes, the study described is a standalone performance study (algorithm only, though "algorithm" here refers to the electronic circuitry and its programmed timing). The device operates independently to simulate clotting times, and its outputs were measured and analyzed directly for accuracy and precision against preset electronic values. There is no human-in-the-loop component in the primary function being tested (electronic simulation and output).
7. Type of Ground Truth Used
The ground truth used is pre-defined electronic simulation timing values. These values were established based on the previous predicate device submission (K940957/S1) and represent the expected outputs for a properly functioning HEMOCHRON® instrument. The device is designed to simulate these specific clotting times.
8. Sample Size for the Training Set
The document does not specify a separate "training set" sample size. The HEMOCHRON® ESVT simulates fixed, predefined timing values. These timings are inherent to the device's design and function, rather than being "trained" on a dataset in the way a machine learning algorithm would be. The precision study assesses the device's consistent execution of these predefined timings.
9. How the Ground Truth for the Training Set Was Established
As mentioned above, there isn't a traditional "training set" in the context of this device. The "ground truth" for the simulated times (90-110s, 290-310s, 490-510s) was established and previously approved in the predicate device submission (K940957/S1). These are intrinsic design specifications for the electronic quality control system, not data derived from training.
§ 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.