(90 days)
The xvision Spine System, with xvision System Software, is intended as an aid for precisely locating anatomical structures in either open or percutaneous spine procedures. Their use is indicated for any medical condition in which the use of stereotactic surgery may be appropriate, and where reference to a rigid anatomical structure, such as the spine or pelvis, can be identified relative to CT imagery of the anatomy. This can include the spinal implant procedures, such as Posterior Pedicle Screw Placement in the thoracic and sacro-lumbar region.
The Headset of the xvision Spine System displays 2D stereotaxic screens and a virtual anatomy screen. The stereotaxic screen is indicated for correlating the tracked instrument location to the registered patient imagery. The virtual screen is indicated for displaying the virtual instrument location to the virtual anatomy to assist in percutaneous visualization and traiectory planning.
The virtual display should not be relied upon solely for absolute positional information and should always be used in conjunction with the displayed stereotaxic information
The xvision Spine (XVS) system is an image-guided navigation system that is designed to assist surgeons in placing pedicle screws accurately, during open or percutaneous computer-assisted spinal surgery. The system consists of a dedicated software, Headset, single use passive reflective markers and reusable components. It uses wireless optical tracking technology and displays to the surgeon the location of the tracked surgical instruments relative to the acquired intraoperative patient's scan, onto the surgical field. The 2D scanned data and 3D reconstructed model, along with tracking information, are projected to the surgeons' retina using a transparent near-eye-display Headset, allowing the surgeon to both look at the patient and the navigation data at the same time.
Here's an analysis of the acceptance criteria and the study proving the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Stated) | Reported Device Performance |
|---|---|
| System Level Accuracy with a mean 3D positional error of 2.0mm and mean trajectory error of 2° | Phantom and Cadaver Studies: |
- Mean positional error: 2.32mm (99% UBL= 2.58mm)
- Mean angular error: 1.66° (99% UBL=1.93°)
Statistically significantly lower than 3mm positional and 3 degrees angular error. |
| Clinical accuracy for pedicle screw placement in sacral/lumbar vertebrae (Gertzbein score) | A total accuracy of 97.7% demonstrated.
Very similar to the literature control rate of 95%. |
| Electrical safety | Tested in accordance with ANSI AAMI ES60601-1:2005/(R)2012 and A1:2012,C1:2009/(R)2012 and A2:2010/(R)2012. Successfully completed. |
| Electromagnetic Compatibility (EMC) | Tested in accordance with IEC 60601-1-2:2014. Successfully completed. |
| Sterilization validation for single-use components | Conducted in accordance with ANSI AAMI ISO 11137-1:2006/(R)2015. Shelf life and packaging testing performed. All tests successfully completed. |
| Cleaning and steam sterilization validation for reusable components | Cleaning: AAMI TIR30:2011. Steam sterilization: ANSI/AAMI/ISO 17665-1:2006/(R)2013 and ANSI/AAMI/ISO 14937:2009/(R)2013. Successfully completed. |
| Biocompatibility of patient contact materials | Verified according to ISO 10993-1:2018 and FDA guidance on the use of ISO 10993-1, June 16, 2016. All tests successfully completed. |
| Software verification and validation | Conducted as required by IEC 62304 and FDA guidance on general principles of software validation, January 11, 2002. |
Note: While the reported positional error (2.32mm) is higher than the stated acceptance criteria (2.0mm), the text explicitly states it's "statistically significantly lower than 3mm," which implies it met a broader acceptable threshold or was deemed clinically acceptable despite exceeding the initial numerical target slightly.
2. Sample size used for the test set and the data provenance:
- Cadaver Study (Accuracy): The sample size for the cadaver study is not explicitly stated as a number of cadavers or individual pedicle screws. It generically mentions "pedicle screws were positioned percutaneously in thoracic and sacro-lumbar vertebrae."
- Provenance: This was an ex-vivo study (cadaver study), implying it likely occurred in a controlled lab environment. No specific country of origin is mentioned, but the submitter is based in Israel.
- Clinical Study (Clinical Accuracy):
- Sample Size: Seventeen (17) subjects.
- Provenance: Prospective, single-arm, multicenter study. No specific country of origin for the clinical sites is provided.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Cadaver Study: The text does not explicitly state the number of experts or their qualifications for establishing ground truth (e.g., measuring actual screw tip positions from post-op scans). This aspect is implicit in the "calculated as the difference between the actual screw tip position... and its virtual tip" description.
- Clinical Study: The ground truth for clinical accuracy was established using the Gertzbein score by "viewing the post-op scans." The number and qualifications of experts (e.g., experienced radiologists, spine surgeons) assessing the Gertzbein score are not specified in the provided text.
4. Adjudication method for the test set:
- The text does not explicitly describe an adjudication method (like 2+1, 3+1) for either the cadaver or the clinical study. It mentions the Gertzbein score being assessed by "viewing the post-op scans," but not how discrepancies among multiple reviewers, if any were used, would be resolved.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, and 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 was not done. The studies described focus on the standalone performance of the xvision Spine system, not on its impact on human reader performance or a comparison of human readers with and without AI assistance. The device is an image-guided navigation system for surgical procedures, assisting the surgeon directly during the procedure rather than improving pre-operative image interpretation by radiologists.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, standalone performance was evaluated. The "System Level Accuracy" criteria and the results from both the bench testing (phantoms) and the cadaver study directly assess the accuracy of the device itself (positional and angular errors) without human in-the-loop influence on the measurement of accuracy. The clinical study also measures the system's accuracy in a real-world setting using post-operative scans.
7. The type of ground truth used:
- Bench Testing (Phantoms): The ground truth was established by the known mechanical properties and precise measurements within the phantom setup, as well as presumably known parameters for partial detectability scenarios.
- Cadaver Study: Ground truth was established by comparing the device's recorded "virtual tip" and "virtual trajectory" to the "actual screw tip position" and "screw orientation" derived from post-operative imaging scans.
- Clinical Study: Ground truth for clinical accuracy was based on the Gertzbein score obtained from viewing post-operative imaging scans. The Gertzbein score implicitly provides a categorization of screw placement accuracy (e.g., ideal, acceptable, minor breach, major breach).
8. The sample size for the training set:
- The text does not provide any information about the sample size used for the training set of the xvision Spine system's algorithms. It focuses entirely on verification and validation testing.
9. How the ground truth for the training set was established:
- Since no information about a training set is provided, there is no information on how its ground truth was established.
§ 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).