(135 days)
The C7 XR™ Imaging System with C7 Dragonfly™ Imaging Catheter is intended for the imaging of coronary arteries and is indicated in patients who are candidates for transluminal interventional procedures. The C7 Dragonfly™ Imaging Catheter is intended for use in vessels 2.0 to 3.5 mm in diameter. The C7 DragonflyTM Imaging Catheter is not intended for use in the left main coronary artery or in a target vessel which has undergone a previous bypass procedure.
The C7 XR™ Imaging System (C7 System) and C7 Dragonfly™ Imaging Catheter (Dragonfly Catheter) provide images of the coronary arteries in patients who are candidates for transluminal interventional procedures. The system utilizes fiber-optic technology to transmit and receive light reflected from coronary tissue in order to produce high resolution, real-time images. The system consists of the C7 XR™ Imaging System (cart-mounted computer and optical engine), the C7 Dragonfly™ Imaging Catheter and Disposable Accessories (sterile, single-use catheter with fiber optic imaging core and external sheath), and the Off-line Review Workstation (personal computer with software to import, maintain and review images).
The provided text describes the C7 XR™ Imaging System and C7 Dragonfly™ Imaging Catheter. Here's an analysis of its performance testing.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria / Endpoint | Device Performance (C7 System & Dragonfly Catheter) |
|---|---|
| Efficacy Endpoint: Median Clear Image Length | 44.0 mm (statistically significant, close to 50 mm system limit) |
| Primary Hypothesis: True, population median Clear Image Length exceeded 24 mm | Met (44.0 mm observed) |
| Intra-observer reliability (Clear Image Length & cross-sectional lumen area) | Lin Concordance Correlation Coefficients ≥ 0.95 (Very good or excellent agreement) |
| Inter-observer reliability (Clear Image Length & cross-sectional lumen area) | Lin Concordance Correlation Coefficients ≥ 0.95 (Very good or excellent agreement) |
| Safety Endpoint: Incidence of predefined safety events (during procedure) | 0% (0/59 subjects) |
| Measurement Accuracy (Diameter) | 3.7% error (upper 95th percentile limits) |
| Measurement Accuracy (Area) | 8.6% error (upper 95th percentile limits) |
| Biocompatibility | Successfully passed ISO 10993:1 and ISO 10993:4 |
| Software Verification & Validation | Passed all requirements |
| International and Performance Standards (Electrical, Electromagnetic, Laser Safety) | Met EN 60601-1, 60601-2-18, 21 CFR Part 1040, IEC 60825 |
| Bench (Performance) Testing | Met performance specifications |
2. Sample Size Used for the Test Set and Data Provenance
The clinical study was a prospective, multi-center study.
The provided text does not explicitly state the specific country of origin for the clinical study data, but it was conducted under a "Significant Risk IDE application", suggesting it was likely conducted in the US.
- Clinical Study Test Set:
- Number of imaged subjects: 59
- Bench Testing (Measurement Accuracy): The sample size for arterial phantoms of different sizes is not explicitly stated.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document mentions "intra- and inter-observer reliability (variability) of cross-sectional lumen area measurements and Clear Image Length measurements were evaluated," and these analyses "concluded that both intra- and inter-reader agreements were very good or excellent." This implies at least two readers were involved in reading the clinical images.
The qualifications of these readers/experts are not specified in the provided text.
4. Adjudication Method for the Test Set
The document mentions "intra- and inter-observer reliability (variability)" and "intra- and inter-reader agreements were very good or excellent. Lin Concordance Correlation Coefficients were all 0.95 or greater." This suggests that multiple readers independently evaluated the images, and their agreement was assessed. However, it does not explicitly describe a specific adjudication method (e.g., 2+1, 3+1 consensus) for resolving discrepancies or establishing a single "ground truth" for the test set from the readers' interpretations. The high concordance coefficients suggest strong agreement, potentially rendering a formal adjudication process unnecessary for the reliability analysis itself.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
No, a multi-reader multi-case (MRMC) comparative effectiveness study evaluating human readers with vs. without AI assistance was not performed or described in this document. The study assessed the device's standalone performance in providing clear images and the reliability of human measurements using the device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The device is an "Imaging System" with a catheter, so "standalone" in the traditional sense of an AI algorithm would not apply. However, the performance assessment described is essentially the standalone performance of the imaging system to produce images that are "suitable for the measurement of lumen diameter and cross-sectional area." The efficacy endpoints (Clear Image Length, measurement accuracy) and reliability analyses assess the quality of the output that human readers then use for diagnosis and measurement. There's no mention of an algorithm autonomously making diagnoses or measurements without human input; rather, the device provides the images for human interpretation.
7. The Type of Ground Truth Used
- Clinical Study (Efficacy): The ground truth for "Clear Image Length" was established by human readers/observers (implied from the intra- and inter-observer reliability analysis). For safety, adverse events were "adjudicated," but the specific type of ground truth beyond clinical observation and expert judgment is not detailed.
- Bench Testing (Measurement Accuracy): For diameter and area measurements, the ground truth was established using a simulated model of the coronary vasculature (arterial phantoms) with known sizes.
8. The Sample Size for the Training Set
The document does not provide any information regarding a training set sample size. This submission is for an imaging system, not explicitly an AI/machine learning algorithm that requires a distinct training phase.
9. How the Ground Truth for the Training Set Was Established
As no training set is mentioned for an AI/machine learning algorithm, the establishment of ground truth for a training set is not applicable based on the provided text.
§ 892.1560 Ultrasonic pulsed echo imaging system.
(a)
Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body tissue to determine the depth or location of the tissue interfaces and to measure the duration of an acoustic pulse from the transmitter to the tissue interface and back to the receiver. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). A biopsy needle guide kit intended for use with an ultrasonic pulsed echo imaging system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.