(190 days)
Merge Hemo displays, measures, and records physiological data from a patient undergoing a cardiac catheterization procedure.
The Hemo System can visualize and capture vital sign values including ECG, impedance respiration, SpO2 and Pleth waveforms, invasive blood pressure, non-invasive blood pressure (NIBP). Thermodilution cardiac output and Fractional Flow Reserve (FFR). The system can display and capture diagnostic quality 12 Lead resting ECG to visualize arrhythmias, and ST-segment changes. Some Hemo systems have an option to measure and display Side-stream End Tidal Carbon Dioxide (EtCO2) along with apnea and respiration rates calculated from the EtCO2 waveform.
The hemodynamic portion of the system is comprised of the Patient Data Module (PDM) and the Merge Hemo Monitor PC. The two units are connected via a serial interface.
All vital parameters are acquired and calculated in the PDM. This data is then transmitted to the Merge Hemo Monitor PC via the serial interface. All data can then be displayed on the Merge Hemo Monitor PC. The Merge Hemo system is not intended to produce alarms for out-of-range conditions.
Patient allergies and current medication information can be entered by the system. If desired and using a third party database the Hemo system can display drug to allergy interaction information.
The system is intended for use in hospital catheterization laboratories and in pre-and post-procedure care areas in the hospital under the close supervision of qualified medical personnel.
Merge Hemo is a hemodynamic recording and display system designed to measure, record, and display vitals signs data for patients undergoing cardiac catheterization procedures.
The addition of a Merge Hemo software feature that provides the ability to calculate and display Fractional Flow Reserve (FFR) values is described. No hardware changes are required in order to enable or perform this functionality.
FFR provides a quantitative assessment of the functional severity of a coronary artery stenosis identified during coronary angiography and cardiac catheterization.
FFR measurement involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery.
The Merge Hemo software user interface displays the pressure waveforms from the third party FFR pressure transducers that are placed distal and proximal to the lesion. When the FFR feature is enabled, the system shows the section of each of the waveforms that is used to calculate the mean pressure.
The results of the pressure waveform recording is expressed as a fraction of the normal blood flow in the coronary artery compared to the maximum achievable blood flow in the same artery. An FFR measurement of 1.0 indicates an artery with normal blood flow. FFR measurements less than 0.80 indicate that ischemia could be caused by blood flow blockage.
The Merge Hemo software initially selects segments of the waveforms to use for FFR calculations but the user can easily change where the values are taken by using the touchscreen interface to move the segment markers along the waveforms. The FFR value recalculates accordingly.
Here's a breakdown of the acceptance criteria and study information for the Merge Hemo device based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria in a table format. However, it describes the performance objective of the FFR calculation and the results of the key comparison study.
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Accuracy and Precision of FFR Calculation | "The Merge Hemo and ACIST FFR systems showed excellent correlation and met all criteria for accuracy and precision. The FFR calculations from both systems were demonstrated to be equivalent." |
| Compatibility with Third-Party FFR Pressure Transducers | "The statistical analysis of the data demonstrated that various makes and models of FFR pressure transducers are compatible with Merge Hemo, including: ACIST Navvus MicroCatheter, St Jude Aeris PressureWire, Volcano Verrata Pressure Guide Wire, Volcano PrimeWire PRESTIGE® PLUS Pressure Guide Wire." "The standardized pressure values generated by FFR transducers are consistent and compatible with Merge Hemo's FFR calculations." |
| Compatibility with Standard Pressure Transducers | "The statistical analysis of the data also demonstrated that various makes and models of standard pressure transducers are compatible with Merge Hemo, including: Edwards TruWave Disposable Pressure Transducer, ICU Medical Transpac IV Disposable Pressure Transducer System, Merit Meritrans® Pressure Transducer." |
| Safety and Effectiveness (overall bench testing) | "All in-house bench tests passed. No issues of safety and effectiveness were raised." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify a numerical sample size for the test set used in the "Integration Test: Comparison of Merge Hemo System vs. ACIST FFR System" or the "Integration Test: Compatibility of Different FFR Pressure Transducers." It refers to "varying the input pressure values" for the physiologic simulator test and "various makes and models" for the compatibility tests without quantifying the number of data points or instances.
- Data Provenance: The data was generated through in-house bench testing using physiologic simulators and commercially available third-party FFR pressure measurement devices and standard pressure transducers. No patient data (retrospective or prospective) was used for these specific tests according to the document.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
There were no experts utilized to establish the ground truth for the test set for the FFR calculation. The ground truth was established by:
- The known input values from physiologic simulators.
- The output from a legally marketed predicate FFR system (ACIST RXi Rapid Exchange FFR System, K132474), which was used as the reference standard for comparison.
4. Adjudication Method for the Test Set
Not applicable. There was no human adjudication process described. The comparison was against known values or a predicate device's output.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was Done
No, an MRMC comparative effectiveness study was not done. The document explicitly states: "No clinical tests were required in order to demonstrate the proper integration of the measurements into Merge Hemo for the calculation of FFR values."
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, a standalone performance evaluation was conducted. The tests described ("Physiologic Simulator Test," "Integration Test: Comparison of Merge Hemo System vs. ACIST FFR System," and "Integration Test: Compatibility of Different FFR Pressure Transducers") evaluate the algorithm's calculation and compatibility purely based on its output compared to a reference, without human interaction influencing the FFR calculation itself after the pressure inputs are provided. The user can move segment markers to re-calculate FFR, but the calculation itself is algorithmic.
7. The Type of Ground Truth Used
The ground truth used was:
- Known values from physiologic simulators (for the "Physiologic Simulator Test").
- Comparison against a predicate device's output (ACIST RXi Rapid Exchange FFR System) for the FFR calculation, which itself is a cleared medical device and serves as a de-facto "expert consensus" or established standard in this context.
8. The Sample Size for the Training Set
The document does not provide any information regarding a training set or its sample size. This suggests that the FFR calculation feature might not rely on machine learning models that require a separate training set. The description of FFR ("The calculation of the FFR ratio is relatively simple and is well known...") implies a deterministic, algorithm-based calculation rather than a learned model.
9. How the Ground Truth for the Training Set Was Established
Since no training set information is provided, this question is not applicable.
§ 870.1425 Programmable diagnostic computer.
(a)
Identification. A programmable diagnostic computer is a device that can be programmed to compute various physiologic or blood flow parameters based on the output from one or more electrodes, transducers, or measuring devices; this device includes any associated commercially supplied programs.(b)
Classification. Class II (performance standards).