(28 days)
The V-TAG is intended to assist with stereotactic guidance, placement, and fixation for the operation of surgical instruments or devices during the planning and operation of neurological procedures performed in conjunction with preoperative and perioperative MR imaging. These procedures include laser coagulation, biopsies, catheter placement and electrode placement procedures.
The V-TAG™ device is a single-use, skull-mounted, rigid trajectory array guide used in stereotactic surgical procedures. The V-TAG can be manipulated to provide a wide range of surgical trajectories into the head. An image-quided neuronavigational system loaded with a stereotactic surgical plan is used to align the V-TAG to the planned trajectory; once aligned, the V-TAG is securely locked to provide a stable instrument guide. After positioning of the V-TAG, magnetic resonance imaging (MRI) is used to confirm alignment with the planned trajectory. Adjustment of the V-TAG may be performed in the MRI scanner to refine or change the trajectory based on updated intraoperative imaging. Intracranial placement of a neurosurgical device or surgical instrument using the V-TAG device is only to be performed after MRI confirmation of the trajectory.
The provided text describes a 510(k) premarket notification for the V-TAG (Voyager Trajectory Array Guide) device, a modification to a previously cleared predicate device (K180854). The core purpose of this submission is to modify the instructions for use to allow for trajectory adjustments in the MRI scanner based on intraoperative imaging.
Here's an analysis of the acceptance criteria and study information provided:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| X, Y, Z errors ≤ 2.0mm | All placements met the acceptance criteria. |
| Angular error of ≤ 2° | All placements met the acceptance criteria. |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: The document states, "For each trial, the beginning alignment was intentionally set to an error greater than 10mm." It does not explicitly state the total number of "trials" or "placements" conducted. It implies multiple trials but lacks a specific numerical count for the test set.
- Data Provenance: Not specified. The document does not mention the country of origin of the data or whether it was retrospective or prospective. Given the context of a 510(k) summary for a medical device, it is highly likely to be prospective testing specifically for this submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- This information is not provided in the document. The testing described appears to be a technical accuracy assessment (measuring alignment deviations) rather than an expert-adjudicated clinical outcome study.
4. Adjudication Method for the Test Set:
- This information is not provided and is not applicable in the context of the described technical accuracy testing. There's no indication of human expert adjudication for the "ground truth" errors, as the errors were likely directly measured against the planned trajectory.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and the effect size of how much human readers improve with AI vs without AI assistance:
- An MRMC comparative effectiveness study was not conducted. This device is a surgical guidance tool, not an AI-assisted diagnostic or interpretation system that would typically warrant such a study. The study focuses on the device's physical accuracy in guiding instruments.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- This question is not directly applicable as the V-TAG is a physical surgical guidance device, not primarily an algorithm or software that operates in a "standalone" fashion. While it works in conjunction with an image-guided neuronavigational system, the performance evaluation here is on the V-TAG's physical accuracy when manipulated by a human in a simulated or real surgical setting, confirmed by imaging. The "algorithm only" concept usually applies to diagnostic interpretations or automated decision-making.
7. The Type of Ground Truth Used:
- The ground truth for the accuracy testing appears to be the pre-planned trajectory of the center lumen to the target. The "projected errors were then calculated," implying a measurement of deviation from this intended target.
8. The Sample Size for the Training Set:
- This information is not applicable as the described study is a performance validation of a physical device's mechanical accuracy, not a machine learning model that requires a training set.
9. How the Ground Truth for the Training Set Was Established:
- This information is not applicable as there is no training set mentioned or implied for this type of device validation.
§ 882.4560 Stereotaxic instrument.
(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).