(382 days)
The ECOM (Endotracheal Cardiac Output Monitoring) System is intended for the monitoring of cardiac output by impedance cardiography while providing airway management by oral intubation with an ECOM Endotracheal Tube. The ECOM System is indicated for use in patients who are expected to be intubated for 24 hours or less and in whom an arterial pressure line is used.
The ECOM (Endotracheal Cardiac Qutput Monitoring) System consists of an ECOM Endotracheal Tube, which contains the electrodes, an ECOM Monitor, an ECOM Tube Cable, and a Laptop Computer. The ECOM System is used in conjunction with a commercially available arterial pressure (AP) line and 3 surface leads on the patient's chest for R-Wave Detection. The Instructions For Use in Appendix 1 includes pictures of each of these components.
The ECOM System is intended for the continuous monitoring of cardiac output by a specially designed endotracheal tube using the principle of bioimpedance (impedance cardiography). Bioimpedance is based on the principal that all biological tissues. including blood, muscle, bone and fat, have electrical properties. Of these, blood is one of the most electrically conductive. Because arterial blood is pulsatile, changes in blood flow result in changes in electrical conductivity and hence the impedance of the blood to electrical current.
The ECOM System measures impedance by injecting a small alternating electrical current (100kHz, 4.0mA) between a pair of electrodes located on the shaft and cuff of the ECOM Endotracheal Tube. Additional electrodes on the ECOM Endotracheal Tube sense the change of impedance caused by changes of the aortic blood flow.
A proprietary ECOM algorithm is used to calculate ventricular stroke volume (SV) from the impedance and arterial pressure waveforms. The stroke volume is multiplied by the patient's heart rate (HR) to calculate cardiac output (CO) in liters per minute. In addition to these parameters, ECOM displays traces of the impedance waveforms, R-Wave Detection signals, systolic and diastolic arterial pressure.
The ECOM Endotracheal Tube contains seven low profile, flexible electrodes affixed to the cuff and shaft of a Standard Endotracheal Tube. The close proximity of the endotracheal tube balloon cuff in relationship to the ascending aorta provides an optimal location from which to measure impedance changes resulting from aortic blood flow.
The ECOM Endotracheal Tube is provided sterile for single use only. It will be available in 6.0mm to 9.0mm sizes, in 0.5mm increments.
The ECOM Monitor, Laptop Computer, ECOM Tube Cable, Lead Wire, Arterial Pressure Cable. Cord Sets, Power Supply, and Power Conditioner are reusable and provided nonsterile.
The provided text describes the ECOM Endotracheal Cardiac Output Monitor. Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly define quantitative acceptance criteria for the ECOM System's performance (e.g., a specific percentage accuracy or an agreement threshold). Instead, it aims to demonstrate "substantial equivalence" to predicate devices. The reported device performance is described qualitatively as being "substantially equivalent at estimating cardiac output as are the predicate non/less invasive devices."
| Performance Metric | Acceptance Criteria (Explicit) | Reported Device Performance |
|---|---|---|
| Cardiac Output Estimation | Not explicitly stated; "Substantial Equivalence" to predicate devices. | Found to be substantially equivalent at estimating cardiac output as are the predicate non/less invasive devices. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not specify the exact number of patients or cardiac output measurements in the final clinical study (test set). It states, "For this study, time matched data for the ECOM System and pulmonary artery catheters were obtained, which provided multiple thermodilution cardiac output measurements." This implies a dataset with paired measurements, but the exact size is not given.
- Data Provenance: Not explicitly stated (e.g., country of origin). The study was framed as "the final step of a three-phase clinical development program" and states, "Imagyn's ECOM System is a new system for the measurement of CO that has been tested in human subjects," confirming prospective clinical data collection for the final validation.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
- The ground truth for the test set was established using pulmonary artery catheters (Swan-Ganz catheters) and thermodilution cardiac output measurements. These are considered a standard clinical method for measuring cardiac output, rather than relying on human expert adjudication of images or waveforms.
- Therefore, the concept of "number of experts" and "qualifications of experts" in the context of establishing ground truth for the ECOM System's accuracy against this invasive gold standard does not directly apply here. The expertise lies in the proper use and interpretation of the thermodilution method.
4. Adjudication Method for the Test Set
- There was no human adjudication method (e.g., 2+1, 3+1). The ground truth was established by another medical device (pulmonary artery catheter using thermodilution), which provides objective numerical measurements.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- No, an MRMC comparative effectiveness study was not performed. This type of study typically involves human readers interpreting diagnostic outputs (like images) and is not relevant for a device that directly measures physiological parameters like cardiac output. The study focused on the agreement between the ECOM system and a reference standard (pulmonary artery catheter).
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
- Yes, the clinical study described is effectively a standalone performance study. The ECOM System, through its proprietary algorithm, calculates cardiac output. The study then compares these calculated values directly against a reference standard (thermodilution measurements from pulmonary artery catheters) without direct human interpretation influencing the ECOM's output. Human users read the result from the device, but the device itself operates in a standalone manner to generate that result.
7. The Type of Ground Truth Used
- The ground truth used was outcomes data / reference device measurements, specifically "multiple thermodilution cardiac output measurements" obtained from "pulmonary artery catheters." This is a generally accepted clinical gold standard for cardiac output measurement.
8. The Sample Size for the Training Set
- The document states that "The two earlier phases were necessary to develop an algorithm for clinical applications and to calibrate the algorithm using actual clinical data." However, it does not specify the sample size for the training set (the data used in these earlier phases).
9. How the Ground Truth for the Training Set was Established
- The document states that the earlier phases were used to "develop an algorithm for clinical applications and to calibrate the algorithm using actual clinical data." It is highly probable that the ground truth for this training and calibration data was also established using clinical reference methods similar to or identical to the ground truth used in the final test set (e.g., pulmonary artery catheters and thermodilution), as this would be standard practice for developing and tuning such a device. However, this is not explicitly detailed for the training set in the provided text.
§ 870.2770 Impedance plethysmograph.
(a)
Identification. An impedance plethysmograph is a device used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs.(b)
Classification. Class II (special controls). The device, when it is a body composition analyzer which is not intended to diagnose or treat any medical condition, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.