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The REFINITY (or REFINITY ST) Rotational IVUS Catheter (REFINITY ST catheter) is intended for the intravascular ultrasound examination of coronary arteries. Intrasound imaging is indicated in patients who are candidates for transluminal interventional procedures. REFINITY (or REFINITY ST) catheters are designed for use as an adjunct to conventional angiographic procedures to provide an image of the vessel lumen and wall structures.

The Refinity and Refinity Short Tip (ST) Rotational IVUS Imaging Catheter consists of two main assemblies: the imaging core and the catheter body. The catheter body is comprised of four sections: a distal section with a .014" compatible rapid exchange guide wire lumen and clear imaging window, a mid-shaft section, a braided proximal shaft, and a telescoping section. The distal, mid, and proximal sections comprise the usable length or working length of the catheter. The telescoping section remains outside of the guiding catheter. The telescoping section allows the imaging core to be advanced and retracted for up to 15 cm of linear movement. The corresponding movement of the transducer occurs from the proximal end of the guidewire exit port to the proximal end of the window portion of the distal section. The imaging core is composed of a hi-torque, flexible, rotating drive cable with a distal outward looking ultrasonic transducer. An electromechanical connector interface at the proximal end makes the connection to the patient interface module (PIM). The PIM-catheter interface consists of an integrated mechanical drive assembly and electrical connection. A flushing port with a one-way valve is used to displace the air initially present within the catheter. The catheter must be flushed with sterile heparinized normal saline prior to use, as this provides the acoustic coupling media required for ultrasonic imaging. The one-way valve helps retain saline in the catheter during use. The catheter body has a distal guide wire lumen with a proximal exit port located 15.5mm (for the short tip model) or 22mm (for the standard tip model) from the distal end. One radiopaque (RO) marker band is embedded 0.5 cm from the tip. In addition, insertion depth indicators are located on the catheter body at 90 cm and 100 cm. The catheter is packaged with a sterile PIM cover, 3 cc and 10 cc syringes, and 13 in extension tubing with a 3-way stopcock. The catheter is for use with the Volcano s5 and CORE® imaging systems with software V3.x.x.

The Volcano Corporation's REFINITY Rotational Intravascular Ultrasound (IVUS) Catheter and REFINITY Short Tip Rotational IVUS Catheter underwent a series of non-clinical device performance tests to demonstrate substantial equivalence to the predicate device, the Volcano Revolution® 45MHz Rotational Intravascular IVUS Imaging Catheter.

Here's an overview of the acceptance criteria and the studies performed, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size and Data Provenance

• Test Set Sample Sizes (where specified):
  • Visual Inspection: "Sample catheters" (specific number not provided).
  • Catheter Prep: "Sample catheters" (specific number not provided).
  • Guide Wire Movement: "Sample catheters" (specific number not provided).
  • Torsion: "Sample catheters" (specific number not provided).
  • Telescope Operation Force: "Sample catheters" (specific number not provided).
  • Force to Overextend Telescope: "Sample catheters" (specific number not provided).
  • Acoustic Emissions: Five Refinity catheters.
  • Image Assessment: Fifteen sets of side-by-side pullback videos were compared by each reviewer.
• Data Provenance: The studies described are non-clinical bench tests and assessments. They appear to be performed internally by Volcano Corporation. There is no mention of country of origin for data or whether it's retrospective or prospective, as these are typically not applicable to bench testing. The "Image Assessment" used "pullback videos of the same vessel," implying in vivo or ex vivo data, but the source (human, animal, phantom) is not specified.

3. Number of Experts and Qualifications for Ground Truth

• Image Assessment: Five independent end-user reviewers and one internal reviewer were used. Their specific qualifications (e.g., "radiologist with 10 years of experience") are not provided, only that they are "end user reviewers."
• B-Mode Testing: Three signal processing engineers assessed qualitative visual image brightness and integrity.

4. Adjudication Method

• Image Assessment: The reviewers "compared the pullback images and rated" various parameters. The text doesn't specify an adjudication method used to combine or reconcile the reviewers' ratings (e.g., 2+1, 3+1 consensus). It simply states they compared and rated.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• The document describes an "Image Assessment" where five independent end-user reviewers and one internal reviewer viewed side-by-side IVUS pullback videos of the same vessel taken with the Revolution (predicate) and Refinity (new device) catheters. They rated various image quality parameters without knowing which catheter produced which image.
• Effect Size: The document only states that "Results must meet the acceptance criteria as stated in the test protocol" and "Results met the acceptance criteria as stated in the test protocol." It does not quantify the effect size of improvement for human readers with AI vs. without AI assistance, as this study was a comparison of two IVUS catheters, not an AI-assisted interpretation study.

6. Standalone (Algorithm Only) Performance

• This information is not applicable. The device described is an Intravascular Ultrasound (IVUS) Catheter, a medical imaging device used by physicians, not an AI algorithm performing diagnostic tasks independently. The performance tests evaluate the physical and imaging characteristics of the catheter itself.

7. Type of Ground Truth Used

• Bench Testing: For most physical and electrical performance tests (e.g., dimensions, tensile strength, NURD, acoustic emissions, thermal dissipation, B-mode parameters), the "ground truth" is defined by known standards or product specifications.
• Biocompatibility: Ground truth is established by ISO 10993 standards and specific test protocols.
• Image Assessment: The "ground truth" for comparison for image quality seems to be the subjective assessment of image quality parameters (axial resolution, lateral resolution, NURD, depth of image penetration, and overall image aesthetics) by expert reviewers in comparison to the predicate device. The text implies a comparative evaluation against the established performance of the predicate, but not a separate, absolute "ground truth" for the images themselves.

8. Sample Size for the Training Set

• This information is not applicable, as this is a medical device, not an AI model that requires a training set.

9. How Ground Truth for Training Set was Established

• This information is not applicable, as this is a medical device, not an AI model that requires a training set.

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