(29 days)
Respiratory Gating for Scanners (RGSC) is used to characterize the patient's respiratory patterns, providing the necessary information to diagnostic devices to acquire images synchronized with the breathing motion. RGSC can also be used to monitor the patient position during the image acquisition.
Respiratory Gating for Scanners (RGSC) is a respiratory motion monitoring device used in the breathing-synchronized acquisition of images on CT and/or PET CT Scanners. It first received FDA clearance in 2015 (K151533). The device consists of the RGSC cabinet (containing workstation unit & real-time unit for user control and interaction), a gating reflector block placed on the patient, a camera system which is used to monitor the reflector block and report the patient's respiratory motion to the workstation, and a visual coaching device. RGSC is operated primarily by radiologist technicians and/or radiotherapists with current licensure and/or certification as required by regional authority, in accordance with the prescription of radiologist or a radiation oncologist and under the general supervision of chief technologists and/or medical physicists, as required by regional authority.
The concepts in the operation of the device include:
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- Breathing-synchronized image acquisition
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- Breathing motion tracking and recording
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- Tracking, recording, and triggering with prospective and retrospective gating for diagnostic imaging
The infrared camera tracks the position and motion of the reflector block, which is placed on the patient's chest or abdomen during this process. This light, plastic block with four reflective markers which face the direction of the camera is in transitory contact with the patient's skin for a limited amount of time (
The provided document is a 510(k) summary for Varian Medical Systems' "Respiratory Gating for Scanners v2.0" (RGSC v2.0), seeking substantial equivalence to their predicate device, "Respiratory Gating for Scanners v1.0 MR1" (RGSC v1.0 MR1), cleared under K151533.
The key changes in RGSC v2.0 from the predicate device are:
- SmartTrack algorithm change to improve detection and tracking of the Reflector Block: The improved algorithm addresses issues with x-ray scatter and pixel noise that sometimes led to invalid results in previous versions. The new method is designed to be more robust in detecting the Reflector Block's position.
- Use of a new filtering method for noise reduction on the breathing amplitude signal: RGSC v2.0 uses a Kalman filtering method, which is presented as more robust against couch motions compared to the simple sliding averaging filter used in the predicate device.
- Support for couch-mounted camera (in addition to previous wall- and ceiling-mounted camera): This expands the system's installation flexibility.
The document explicitly states: "No animal or clinical tests are being submitted to establish substantial equivalence with the predicate device." This means that the acceptance criteria and performance data for this device are based on non-clinical verification and validation testing, not on clinical studies involving human or animal subjects that directly measure diagnostic accuracy or clinical outcomes.
Therefore, the requested information regarding certain aspects of clinical studies, such as sample size for test sets, data provenance, expert consensus, adjudication methods, MRMC studies, standalone algorithm performance, and ground truth establishment for such studies, is not applicable to this submission as no clinical performance data was provided or required for the substantial equivalence determination.
The submission focuses on engineering validation to demonstrate that the changes do not negatively impact safety and effectiveness and that the device performs its intended use as designed, consistent with the predicate.
Here's a breakdown of the available information based on the prompt's request:
1. A table of acceptance criteria and the reported device performance:
Since no clinical accuracy data is presented, acceptance criteria are generally implied by conformance to design specifications, industry standards, and the successful completion of non-clinical verification and validation tests. The "reported device performance" is described qualitatively by the improvements made.
| Acceptance Criteria (Implied by V&V) | Reported Device Performance |
|---|---|
| SmartTrack Algorithm Performance: | |
| Robust detection and tracking of Reflector Block, minimizing invalid results due to x-ray scatter and pixel noise. | Improved calculation method that explicitly removes noisy and bright pixels randomly caused by x-ray scatter from the Reflector Block size calculation, leading to increased robustness in detecting the Reflector Block position. (Qualitative improvement) |
| Breathing Amplitude Signal Noise Reduction: | |
| Effective noise reduction to ensure accurate breathing amplitude signal, especially robust against couch motions. | New Kalman filtering method applied for noise reduction on the amplitude signal, described as more robust against couch motions compared to the predicate's simple sliding averaging filter. (Qualitative improvement) |
| Camera Mounting Options: | |
| Extend compatibility to include couch-mounted camera with specified tracking distances. | Yes, supports couch-mounted camera with a tracking distance of 1.0 to 2.5 meters using a video camera with a 12mm lens. Retains support for wall- and ceiling-mounted cameras (2.5 to 5.6 meters with 25mm lens). (Functional enhancement) |
| Overall Safety and Effectiveness: | |
| Device operates safely and effectively for its intended use, with no negative impact from changes. | "The non-clinical Verification and Validation testing demonstrates that these changes do not negatively impact the safety and effectiveness of the subject device and the subject device performs its intended use as designed through the product's functional, usability, and safety requirements." Confirmed compliance with numerous standards including electrical safety (IEC 60601-1, IEC 60601-1-2), human factors (IEC 62366-1), and quality systems (21 CFR §820, ISO 13485, ISO 14971, IEC 62304). (Overall Conformance and Functional Performance) |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample size: Not applicable/Not specified for clinical data, as no clinical tests were submitted. The V&V testing involved various non-clinical scenarios (simulated use, bench testing).
- Data provenance: Not applicable for clinical data. For non-clinical V&V, the testing was conducted by Varian Medical Systems. Specific country of origin for the non-clinical test data is not detailed, but Varian Medical Systems is based in Palo Alto, CA, USA.
- Retrospective or prospective: Not applicable, as no clinical studies were submitted.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Not applicable, as no clinical studies with expert-adjudicated ground truth were submitted.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable, as no clinical studies requiring ground truth adjudication were submitted.
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
- No, an MRMC comparative effectiveness study was not done or submitted. The device is a "Respiratory Gating for Scanners," which is an input device for diagnostic imaging, not an AI software intended for image interpretation or diagnosis that would typically involve human reader performance studies.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No "standalone" performance study in the context of diagnostic accuracy was explicitly mentioned as having been performed or submitted. The device's function is to characterize respiratory patterns and provide information to diagnostic devices. Its performance is evaluated through its ability to accurately detect and track the reflector block and filter the breathing signal, which are functional aspects demonstrated by non-clinical V&V, not diagnostic output.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- For the non-clinical verification and validation testing, the "ground truth" would be the engineering specifications, known physical parameters, simulated conditions, and expected system behavior, rather than clinical ground truth (e.g., pathology or patient outcomes).
8. The sample size for the training set
- Not applicable. The document does not describe the device as employing machine learning that would require a "training set" in the conventional sense for AI clinical performance. The changes involve algorithmic improvements (SmartTrack, Kalman filter) but these are described in terms of engineering solutions rather than data-driven machine learning models.
9. How the ground truth for the training set was established
- Not applicable. See point 8.
§ 892.1750 Computed tomography x-ray system.
(a)
Identification. A computed tomography x-ray system is a diagnostic x-ray system intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data from the same axial plane taken at different angles. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.