(51 days)
The LessRay™ is intended for use in any application where a fluoroscope is incorporated to aid in diagnosis and treatment of disease.
The LessRay™ is a stand-alone computer display system interfaced to a fluoroscope with a video cable. The images produced by the fluoroscope are transmitted to a frame grabber in the computer where the images are enhanced and then displayed on the LessRay™ monitor. Each image is displayed on the LessRay™ monitor at the same time as the corresponding original image is displayed on the fluoroscope monitor(s).
Here's an analysis of the acceptance criteria and study information for the LessRay™ device based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided summary does not explicitly state quantitative acceptance criteria in the form of specific metrics (e.g., minimum SNR improvement, maximum noise reduction percentage) that the LessRay™ device needed to meet. Instead, the "Performance Data" section discusses "validation tests" designed to establish substantial equivalence to the predicate device.
The reported device performance is described more qualitatively in relation to these tests and the comparison with the predicate device.
| Test/Characteristic | Acceptance Criteria (Explicitly Stated) | Reported Device Performance |
|---|---|---|
| Validation Test 1: | Not explicitly stated as a quantitative criterion. Implied: Demonstrated image improvement under low dose/pulse conditions. | The LessRay™ system can merge sequential and non-sequential images of the same anatomy to enhance image quality. It uses an averaging algorithm to use full-dose images to enhance image quality. "Validation testing demonstrate that the LessRay™ provides accurate and clinically relevant images." |
| Validation Test 2: Blocked Anatomy | Not explicitly stated. Implied: Effective image processing despite blocked anatomy. | (Performance not detailed beyond its execution) |
| Validation Test 3: Parallax Test | Not explicitly stated. Implied: Accurate image handling despite parallax. | (Performance not detailed beyond its execution) |
| Validation Test 4: Pig Study | Not explicitly stated. Implied: Safe and effective in a simulated clinical setting. | (Performance not detailed beyond its execution) |
| Overall Equivalence | As safe and effective as the predicate device (3DFIS). | "Performance testing demonstrates that the LessRay™ is as safe and effective as the 3DFIS." (Based on identical indication, similar technological characteristics, and results of performance testing). Provides reduced noise images. |
| Electrical Safety and EMC Standards | Compliance with IEC 60601-1 and IEC 60601-1-2. | The LessRay™ system meets these standards. |
2. Sample Size Used for the Test Set and Data Provenance
The document mentions "Validation Test 4 Pig Study." This implies the test set involved animal data. However:
- The sample size for the test set (e.g., number of pigs, number of images acquired) is not specified.
- The data provenance (e.g., country of origin, retrospective or prospective) is not specified beyond it being a "Pig Study."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
There is no information provided regarding the number or qualifications of experts used to establish ground truth for any of the validation tests, including the Pig Study. The document primarily focuses on technical and comparative performance rather than human-in-the-loop evaluation for establishing ground truth.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1, none) for the test set.
5. 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
There is no mention of a multi-reader multi-case (MRMC) comparative effectiveness study. The validation tests appear to be primarily focused on the device's technical performance and comparison to a predicate, not on how it impacts human reader performance or an "AI assistance" scenario (as the device is image enhancement, not an AI diagnostic tool in the modern sense).
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the studies described are predominantly standalone performance assessments of the LessRay™ device. The "Validation Test 1 Low Dose/Pulse Image Improvement," "Validation Test 2 Blocked Anatomy," "Validation Test 3 Parallax Test," and "Validation Test 4 Pig Study" appear to evaluate the algorithm's output directly, rather than its impact on a human reader's decision-making. The description states, "The images produced by the fluoroscope are transmitted to a frame grabber in the computer where the images are enhanced and then displayed on the LessRay™ monitor." This workflow implies the device processes and displays enhanced images, and the validation tests would assess the quality of these enhanced images.
7. The Type of Ground Truth Used
The document does not explicitly state the type of ground truth used for the validation tests.
- For "Low Dose/Pulse Image Improvement," ground truth might involve comparing enhanced images to high-dose images or using objective image quality metrics.
- For "Blocked Anatomy" and "Parallax Test," ground truth would likely involve successful visualization or elimination of artifacts under controlled conditions.
- For the "Pig Study," while not explicitly stated, ground truth would likely refer to the actual anatomical structures or known pathological conditions within the pig model, potentially confirmed by other imaging modalities or direct observation, against which the fluoroscopic images were judged for clarity and diagnostic utility.
8. The Sample Size for the Training Set
The document does not provide any information about a training set or its sample size. The LessRay™ device is described as using an "averaging algorithm" to enhance images, which implies a rule-based or signal-processing approach rather than a machine learning model that typically requires a large training set.
9. How the Ground Truth for the Training Set Was Established
Since there is no mention of a training set, there is no information provided on how ground truth for a training set would have been established.
§ 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.