(30 days)
The GR40CW Digital X-ray Imaging System is intended for use in general projection radiographic applications wherever conventional screen-film systems or CR systems may be used. This device is not intended for mammographic applications.
The GR40CW digital X-ray imaging system consists of Detector, Power supply box, Battery pack, Battery charger, Access point, CIB(Control Interface Box), Workstation, Barcode scanner, Main cable and software for image acquisition and image processing and does not include the X-ray generator. This system is used to capture images by transmitting X-ray to a patient's body. The X-ray passing through a patient's body is sent to the detector and then converted into electrical signals. These signals go through the process of amplification and digital data conversion in the signal process device before being sent to the S-Station (Operation Software) and saved in DICOM file, a standard for medical imaging. The captured images are sent to the Picture Archiving & Communication System (PACS) server, and can be used for reading images. The GR40CW digital X-ray imaging system was previously cleared with K180543, and through this premarket notification, we would like to add more configurations in the previously cleared GR40CW as three detectors are newly added, and some software features called as SimGrid, S-Enhance, BSI (Bone Suppression Image), Remote View and manual Stitching are newly added as stated below. SimGrid software option, cleared with K171119. is able to compensate the contrast loss due to scatter radiations, primarily acquisitions without a physical anti-scatter grid. BSI software option suppresses bone anatomy and S-Enhance is renamed from Tube & Line Enhancement (TLE), which was cleared before with the predicate device GM85 at K171119, to enhance visibility of tubes and lines and provide enhanced images separately from original images. In this submission, the scope of S-Enhance is expanded from tubes and lines on chest images to foreign body (e.g. tubes, lines and needles) and urinary stones on chest, abdomen, and L-spine. And Manual Stitching to capture a body part that is larger than the detector's by capturing multiple images and Remote View function to remote access to view the current image on the workstation through a web browser. It was determined that the level of concern for the software contained in the GR40CW digital X-ray imaging system was Moderate in accordance with the FDA guidance for the Content of Premarket Submissions for Software Contained in Medical Device".
Here's a breakdown of the acceptance criteria and study information for the GR40CW device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly list a table of "acceptance criteria" with pass/fail thresholds in the typical sense for product validation. Instead, it focuses on demonstrating substantial equivalence to predicate devices. The performance evaluation is primarily comparative.
However, based on the non-clinical and clinical data descriptions, we can infer the key performance areas evaluated and the general finding of equivalence.
| Performance Metric Area | Acceptance Criteria (Inferred from Substantial Equivalence) | Reported Device Performance |
|---|---|---|
| Non-Clinical Data | Performance equivalent to predicate device (K180543) | No significant difference in non-clinical testing data (MTF and DQE measurements) compared to the predicate device. |
| MTF (Modulation Transfer Function) | Equivalent to predicate device | Met (no significant difference reported) |
| DQE (Detective Quantum Efficiency) | Equivalent to predicate device | Met (no significant difference reported) |
| Clinical Data (S-Enhance) | Image quality equivalent to predicate devices for new detector and S-Enhance (expanded scope) | No significant difference in the average score of image quality evaluation between the proposed device and the predicate device. S-Enhance confirmed to generate clear companion images for foreign bodies and urinary stones. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set for New Detector and S-Enhance (Clinical Data):
- Sample Size: Not explicitly stated as a number of images or patients. It mentions "Anthropomorphic phantom images were provided"; and "these images were not necessary to establish substantial equivalence... but they provide further evidence...".
- Data Provenance: Not explicitly stated (e.g., country of origin). The study used "Anthropomorphic phantom images," which are specialized phantoms designed to mimic human anatomy for imaging studies. This is a controlled, laboratory-based setup rather than real patient data. It is a prospective study design as the images were "provided" for evaluation.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not explicitly stated. The document mentions "They were evaluated by professional radiologists." The exact number (e.g., 3, 5, 10) is not provided.
- Qualifications: "Professional radiologists." No specific years of experience or subspecialty are listed.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly stated. The text only says "They were evaluated by professional radiologists." This implies individual evaluation, but it doesn't describe a consensus or majority rule method if multiple radiologists were involved, nor does it specify if a single radiologist was the sole evaluator.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
- MRMC Study: No, a formal MRMC comparative effectiveness study, comparing human readers with AI assistance versus without AI assistance, was not explicitly detailed or performed as part of this submission. The clinical data section focuses on "Anthropomorphic phantom images" evaluated by radiologists to demonstrate equivalence of the device (including the S-Enhance feature) to predicate devices, not on the improvement of human performance using the AI feature.
- Effect Size: Not applicable, as an MRMC study demonstrating human reader improvement with AI assistance was not described.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
- Standalone Performance: The non-clinical data provides standalone performance metrics for the device components like MTF and DQE (measured by IEC 62220-1), which characterize the imaging chain's inherent physical performance.
- For the software features like S-Enhance, the clinical data describes evaluations by radiologists of images generated by the software. While radiologists evaluate the output, the core performance of the S-Enhance algorithm in creating the companion images is assessed based on their ability to "provide clear visibility for foreign bodies such as lines, and needles, and urinary stones." This suggests a form of standalone performance evaluation of the algorithm's output, even if human experts are interpreting that output. The submission aims to show the complete system works as intended and that S-Enhance produces images with desired characteristics.
7. The Type of Ground Truth Used
- Ground Truth Type: For the clinical evaluation regarding the new detector and S-Enhance, the ground truth was expert consensus/opinion (professional radiologists) on the "image quality evaluation" and the "clear visibility for foreign bodies... and urinary stones" in images generated from anthropomorphic phantoms. Phantoms provide a known truth in terms of implanted objects.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not provided or discussed in this document. This submission pertains to modifications to an already cleared device, and the focus is on the performance of the new detectors and expanded software features (S-Enhance). Details about the training data for the S-Enhance or other software algorithms are not included.
9. How the Ground Truth for the Training Set Was Established
- Training Set Ground Truth Establishment: Not provided or discussed, as the training set sample size was not mentioned.
§ 892.1680 Stationary x-ray system.
(a)
Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate and control x-rays for examination of various anatomical regions. 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). A radiographic contrast tray or radiology diagnostic kit intended for use with a stationary 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.