(154 days)
NuVasive® LessRay® with Enhanced Tracking is intended for use in any application where a fluoroscope is incorporated to aid in diagnosis and treatment of disease.
LessRay is a software application which can be interfaced to a fluoroscope with a video cable. The images produced by the fluoroscope are transmitted to a frame grabber in the computer running LessRay where the images are enhanced and then displayed. When used in connection with the low dose and/or pulse setting on the fluoroscope, the user can improve the quality (clarity, contrast, noise level, and usability-) of a noisy (low-quality) image. Using this system, much of the graininess of low radiation dose images can be eliminated. This allows for greater utility of low dose imaging. LessRay with Tracking provided the additional feature of being able to interface LessRay with a tracking system in order to aid the C-arm technician in positioning the fluoroscope between the various views of the patient necessary for the intervention. LessRay with Tracking ensures that the fluoroscope is centered over the correct anatomy prior to taking any additional x-ray images.
NuVasive LessRay with Enhanced Tracking has additional capability of instrument tracking to aid the user in positioning an instrument using prior baseline x-rays. A tracker is attached to the instrument and as the instrument moves, the tracking system connected to LessRay tracks the location of the instrument. NuVasive LessRay with Enhanced Tracking uses this information to aid the user in positioning the instrument.
The NuVasive® LessRay® with Enhanced Tracking device is intended for use in fluoroscopic applications to aid in diagnosis and treatment. The study performed focuses on the new "Enhanced Tracking" feature which aids in instrument positioning.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with specific numerical targets. Instead, the performance claims for the "Enhanced Tracking" functionality are described qualitatively. Based on the provided text, here’s a representation of the acceptance criteria and the claimed performance:
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Instrument Tracking (Relocalization Ability): Allow the user to reposition an instrument to a previously identified location. | Confirmed through Verification of Instrument Tracking. |
| GUI Functionality: Graphical User Interface performs according to specifications. | Confirmed through Verification of Graphical User Interface (GUI). |
| Clinical Efficiency (Relocalization): Instruments can be relocalized with fewer X-ray images. | Confirmed through Validation of Instrument Tracking. |
| Accuracy (Relocalization): Instruments can be relocalized with greater accuracy. | Confirmed through Validation of Instrument Tracking. |
| Time Efficiency (Relocalization): Instruments can be relocalized in less time than conventional fluoroscopy. | Confirmed through Validation of Instrument Tracking. |
| Core Functionalities (Regression): Maintain image alignment, glyph tracking, and image registration performance. | Confirmed through Regression Testing. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the sample size for any of the test sets used for verification or validation of the Enhanced Tracking feature. The provenance of the data (e.g., country of origin, retrospective or prospective) is also not mentioned.
3. Number of Experts and Qualifications
The document does not mention the number or qualifications of experts used to establish a ground truth for the test set related to the "Enhanced Tracking" feature.
(Note: Footnote 1 refers to a "side by side visual comparison of 30 image pairs with and without LessRay processing" for evaluating image quality improvement, but this appears to be related to the original LessRay functionality and not specifically the new Enhanced Tracking feature. It also doesn't specify experts or their qualifications for this particular evaluation).
4. Adjudication Method
The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for the test set used for the Enhanced Tracking feature.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance is explicitly described for the "Enhanced Tracking" feature.
6. Standalone Performance
The performance data are described for the "Enhanced Tracking" functionality, indicating the capabilities of the algorithm in aiding instrument positioning. The validation focuses on the device's ability to help users achieve specific outcomes (fewer X-rays, greater accuracy, less time). While it describes the performance of the device's feature, it's not a standalone performance study in the sense of an algorithm making a diagnostic decision by itself without human input, as the device is designed to aid the user.
7. Type of Ground Truth
The document doesn't explicitly state the type of ground truth used for the verification and validation of the "Enhanced Tracking" feature. Given the nature of the evaluation (positioning an instrument), the "ground truth" would likely be derived from:
- Physical measurements/known states: For verifying the accuracy of instrument tracking systems against known positions.
- Procedural compliance/expert observation: For validating that the GUI performs as intended and that the instrument can be consistently relocalized.
- Observed outcomes: For validating reduced X-ray images, improved accuracy, and reduced time.
8. Sample Size for the Training Set
The document does not mention any training set or its sample size. This suggests that the "Enhanced Tracking" feature is likely based on engineered algorithms or heuristics rather than machine learning models that require a distinct training phase with labeled data.
9. How the Ground Truth for the Training Set was Established
As no training set is mentioned, the method for establishing its ground truth is also not described.
§ 892.1650 Image-intensified fluoroscopic x-ray system.
(a)
Identification. An image-intensified fluoroscopic x-ray system is a device intended to visualize anatomical structures by converting a pattern of x-radiation into a visible image through electronic amplification. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). An anthrogram tray or radiology dental tray intended for use with an image-intensified fluoroscopic x-ray system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9. In addition, when intended as an accessory to the device described in paragraph (a) of this section, the fluoroscopic compression device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.