(123 days)
The ACIST HDi System is intended to be used for ultrasound examination of coronary and peripheral intravascular pathology. Intravascular ultrasound in indicated in patients who are candidates for transluminal interventional procedures.
The ACIST Kodama Intravascular Ultrasound Catheter is intended for use with the ACIST HD System.
The primary function of HDi System is to collect reflected ultrasonic (sound) waves from the Kodama catheter and render an intravascular image on the console touchscreen. The catheter emits sound energy from a transducer at the tip; sound waves reflected from the inner vascular tissues are received from the transducer and sent to the console where a high resolution, cross-sectional image is displayed on the touchscreen in real-time.
The main devices are the Console, Patient Interface Module (PIM), Linear Translation System (LTS) (optional), and Kodama Catheter.
The console houses hardware and software required to generate the energy used to excite the transducer in the Kodama catheter; it is the center of control and system architecture for how signals are acquired, processed, images constructed and presented, and overall power management and control of the PIM and LTS. The system digitally records case images, provides a review of recorded cases, and provides for the archival of recorded cases onto removable media.
The handheld PIM provides the electromechanical interface between the catheter and the console. It also provides the mechanical interface to secure the catheter, as well as the mechanical energy to rotate the catheter's imaging assembly. The LTS device provides automated, controlled linear translation of the catheter by providing mechanical coupling to the PIM and to the catheter's telescoping anchor as the PIM is pulled back along the longitudinal axis. The coupling between the LTS and PIM and LTS to catheter is strictly mechanical. The LTS device allows the user to perform automatic pullbacks and can be controlled via touchscreen buttons on the console or the buttons on the LTS. Manual pullbacks may be performed with or without the LTS, making the use of the LTS optional to the user.
The Kodama Catheter emits sound energy from its transducer at the distal tip, which is guided into the coronary and peripheral vasculature. The catheter can be operated at two different frequencies, 40MHz and/or 60MHz. The electrical energy from the catheter is transmitted, via the coaxial cable embedded in the drive cable, back to the HDi console for signal processing and image reconstruction.
The ACIST HDi System and Kodama Intravascular Ultrasound Catheter are intended for ultrasound examination of coronary and peripheral intravascular pathology in patients undergoing transluminal interventional procedures. The device's primary function is to collect reflected ultrasonic waves from the Kodama catheter and display an intravascular image on the console touchscreen in real-time. This submission focuses on software modifications to extend the field of view for larger peripheral vessels.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| The Acquire screen is displayed during Imaging, Recording and Pullback and it has appropriate functional elements, including the new "Diameter" button. | Verified with passing results. |
| The Zoom/Decimation function allows the image to be magnified to the specified depth range in the extended field of view. | Verified with passing results. |
| The time gain compensation (TGC) control curve is controlled dynamically by the Diameter selection and covers the appropriate anatomical depth range. | Verified with passing results. |
| Users can utilize the new software features and interpret the resulting images correctly and that there were not new use errors identified. (Primary changes observed by the user are Graphical User Interface (GUI) changes to the "diameter" selection feature that sets the system field of view range and frequency). | All design validation testing was executed with passing results. |
| IVUS image quality generated by the HDi System with the modified system software is clinically useful at extended field of view diameters (12, 16, and 20 mm) and is equivalent to the current commercially available software within current field of view (6, 8, and 10 mm). | Physician assessment confirmed: |
| • IVUS images generated with the modified system software at 10mm field of view are substantially equivalent to IVUS images generated by the current system software at 10 mm field of view. | |
| • All IVUS images generated by the modified system software at 20 mm field of view are clinically useful, especially for vessel lumen measurement and determining stent strut location. | |
| • All IVUS images generated by the modified system software which measured the lumen at 20 mm field of view do not show any differences between 1.0 mm/s pullback speed (30 f/s) and 10.0 mm/s pullback speed (60 f/s). | |
| The device meets established performance specifications and performs as intended, with no new safety or performance issues raised. | Test results demonstrate the HDi System met the established performance specifications and performs as intended. No new safety or performance issues were raised during the testing. |
| The overall risk profile of the device has not changed. | One new use related risk was identified due to changes in the software user interface selection options; however, the overall risk profile of the device has not changed. |
2. Sample Size Used for the Test Set and Data Provenance
The document mentions an "animal study validation testing" to evaluate image quality. However, the specific sample size (number of animals or images) used for this test set is not provided. The provenance of this data is prospective as it was collected specifically for validation testing. The country of origin is not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document mentions "Physician assessment" for confirming the clinical utility and equivalence of the IVUS images. However, the number of experts involved and their specific qualifications (e.g., cardiologist with X years of experience in IVUS) are not provided.
4. Adjudication Method for the Test Set
The document states "Physician assessment confirmed," implying that experts evaluated the images. However, the specific adjudication method (e.g., 2+1, 3+1, none) used to establish ground truth or resolve discrepancies among multiple expert opinions (if applicable) is not specified.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance was not done or mentioned in the provided text. The study focused on the performance of the modified device itself, not on its impact on human reader performance.
6. If a Standalone Performance (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, in part. The "Design verification testing" and "Design validation testing" focused on the software and system's technical and functional performance, including the display of functional elements, zoom/decimation, and TGC control. This can be considered a form of standalone performance assessment as it evaluated the algorithm's output (images) and user interface functionality directly. The animal study also tested the system's ability to generate clinically useful images.
7. The Type of Ground Truth Used
The ground truth for the image quality assessment in the animal study was established through expert consensus/assessment by physicians. They confirmed the clinical utility and equivalence of the IVUS images.
8. The Sample Size for the Training Set
The document primarily describes validation and verification testing of modifications to existing software. It does not mention a separate "training set" or sample size for training an artificial intelligence or machine learning algorithm. This suggests that the device's image generation and display capabilities are based on established algorithms rather than a newly trained AI model.
9. How the Ground Truth for the Training Set Was Established
As no separate training set for an AI/ML algorithm is explicitly mentioned for this modification, the method for establishing its ground truth is not applicable based on the provided text. The modifications appear to be primarily functional extensions of existing software and firmware, rather than the introduction of a new learnable model.
§ 870.1200 Diagnostic intravascular catheter.
(a)
Identification. An intravascular diagnostic catheter is a device used to record intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among others.(b)
Classification. Class II (performance standards).