(223 days)
The 0.014" Willow Guidewire is intended for general intravascular use, including neurovascular and peripheral vasculatures. It can be used to selectively introduce and position catheters and other interventional devices within the peripheral and neuro vasculature. This device should be used only by physicians trained in percutaneous, intravascular techniques and procedures.
Like the predicate device, the 0.014" Willow Guidewire is a single-use product with a shapeable tip available in straight and pre-shaped configurations, used to gain intravascular access to facilitate the positioning and exchange of interventional devices in small diameter, tortuous vasculature for neuro and peripheral diagnostic and interventional procedures. The wire can be torqued to facilitate navigation through the vasculature. The 0.014" Willow Guidewire comes in three stiffness profiles: Soft, Standard and Support.
The provided FDA 510(k) clearance letter and summary for the 0.014" Willow Guidewire do not describe a study involving an AI/Machine Learning device.
Instead, this document describes a traditional medical device (a guidewire) and its clearance process through substantial equivalence to a legally marketed predicate device. The "acceptance criteria" and "study that proves the device meets the acceptance criteria" in this context refer to engineering and biocompatibility bench testing, not clinical performance studies for an AI algorithm.
Therefore, many of the questions related to AI/ML device performance (like sample size for test/training sets, expert ground truth, adjudication methods, MRMC studies, standalone performance, effect size of AI assistance) are not applicable to this document.
However, I can extract the relevant information regarding the acceptance criteria and the engineering study (bench performance testing) for the 0.014" Willow Guidewire.
Acceptance Criteria and Study for the 0.014" Willow Guidewire
The 0.014" Willow Guidewire is a traditional medical device, not an AI/ML device. Therefore, the "acceptance criteria" and "study" refer to engineering specifications and bench performance testing, along with biocompatibility testing, to demonstrate substantial equivalence to a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are generally implied by "Acceptance criteria were met" or "considered acceptable" for each test. The reported device performance is that these criteria were successfully achieved.
| Test | Test Method Summary | Reported Device Performance / Conclusions |
|---|---|---|
| Bench Performance Testing | ||
| Coating Lubricity | Hydrophilic coating lubricity was assessed after multiple pull cycles through silicone pads. | Acceptance criteria were met. |
| Coating Durability | Coating durability was assessed after repeating multiple pull cycles through silicone pads. | Acceptance criteria were met. |
| Coating Integrity | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Inspected pre- and post-simulated use tracking with comparison to predicate. | Coating integrity was reported and considered acceptable. |
| Corrosion Resistance | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). | Acceptance criteria were met. |
| Dimensional & Visual Insp. | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Verified key dimensions. | Acceptance criteria were met. |
| Flex Fatigue | Subjected guidewire to multiple flexure cycles around cylindrical pins. | Acceptance criteria were met. |
| Fracture | Subjected guidewire to multiple wrappings around cylinder and visually inspected for signs of fracture. | Acceptance criteria were met. |
| Kink Resistance | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Wrapped guidewire around test fixture with clinically relevant radii. | Acceptance criteria were met. |
| Particulate Characterization | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Counted particulates after tracking through tortuous simulated use model, with comparison to predicate. | Particulate counts were reported and considered acceptable. |
| Radiopacity | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Evaluated subject and predicate guidewires under fluoroscopy. | All Willow Guidewires demonstrated acceptable radiopacity; comparable to predicate. |
| Simulated Use | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Tested with microcatheter, introducer, and torque device while navigating to target in a tortuous simulated use model. | Acceptance criteria were met. |
| Tensile Strength | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Measured force to break at each bond. | Acceptance criteria were met. |
| Tip Flexibility | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Measured force to deflect tip at 5 mm, 10 mm, and 20 mm gauge lengths, compared to predicate. | Acceptance criteria were met. |
| Tip Shapeability | Shaped the guidewire tip three times per labeling. | Acceptance criteria were met. |
| Tip Shape Retention | Measured tip shape retention after tracking through a tortuous simulated use model. | Acceptance criteria were met. |
| Torqueability | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Tracked through tortuous simulated use model; evaluated steerability and torque response. | Acceptance criteria were met. |
| Torque Strength | Per FDA guidance "Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling" (2019). Recorded rotations until failure. | Acceptance criteria were met. |
| Biocompatibility Testing | ||
| Acute Systemic Toxicity | Per ISO 10993-11. | Pass: No evidence of acute systemic toxicity. |
| Compliment Activation | Per ISO 10993-4. | Pass: Non-activator. |
| Cytotoxicity – MEM Elution | Per ISO 10993-5. | Pass: Non-cytotoxic. |
| Hemolysis | Per ISO 10993-4. | Pass: Non-hemolytic. |
| Intracutaneous Reactivity | Per ISO 10993-10. | Pass: Non-reactive. |
| In Vivo Thrombogenicity | Per ISO 10993-4. | Pass: Non-Thrombogenic. |
| Pyrogenicity | Per ISO 10993-11. | Pass: Non-pyrogenic. |
| Sensitization | Per ISO 10993-10. | Pass: Non-sensitizing. |
Information Not Applicable (NA) to this Device/Submission:
The following questions are specifically targeted at AI/ML medical devices and are not relevant to the 0.014" Willow Guidewire, which is a traditional physical medical device.
- Sample size used for the test set and the data provenance: NA (This is a physical device, not an AI/ML algorithm requiring a data test set.)
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: NA (No "ground truth" in the AI/ML sense is established for this type of device.)
- Adjudication method (e.g. 2+1, 3+1, none) for the test set: NA (No adjudication method described for physical device testing.)
- 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: NA (No MRMC study or AI assistance involved.)
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: NA (Not an algorithm.)
- The type of ground truth used (expert consensus, pathology, outcomes data, etc.): NA (Ground truth is not a concept applied in this context; performance is measured against engineering specifications and predicate characteristics.)
- The sample size for the training set: NA (No training set for a physical device.)
- How the ground truth for the training set was established: NA (No training set or ground truth in this context.)
§ 870.1330 Catheter guide wire.
(a)
Identification. A catheter guide wire is a coiled wire that is designed to fit inside a percutaneous catheter for the purpose of directing the catheter through a blood vessel.(b)
Classification. Class II (special controls). The device, when it is a torque device that is manually operated, non-patient contacting, and intended to manipulate non-cerebral vascular guide wires, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.