(129 days)
PreXion3D Explorer EX is intended to produce two-dimensional digital x-ray images including panoramic image and three-dimensional digital x-ray images of the dental, oral, maxillofacial region, ENT (Ear, Nose and Throat) and neck region at the direction of healthcare professionals as diagnostic support for adult and pediatric patients.
This device is not intended for use on patients less than approximately 21 kg (46 lb) in weight and 113 cm (44.5 in) in height; these height and weight measurements approximately correspond to that of an average 5 year old. Use of equipment and exposure settings designed for adults of average size can result in excessive radiation exposure for a smaller patient. Studies have shown that pediatic patients may be more radiosensitive than adults (i.e., the cancer risk per unit dose of ionizing radiation is higher), and so unnecessary radiation exposure is of particular concern for pediatric patients.
PreXion3D Explorer EX consists of a scanner, which is used for generating X-ray and detecting image data, and a Console, which is used for operating the scanner and managing the data. The scan data acquired by the scanner will be transferred to the Console. PreXion3D Explorer EX Image Analysis System will then perform the image analysis (2D/3D) or image edition (creating cross-section diagram, etc.), and output the image to a printer.
X-ray image data is acquired while the rotation arm is rotating around the secured "patient's head" at a constant speed. X-rays, which are emitted from X-ray generator (built in one side of rotation arm), pass through a patient and are detected by the flat panel detector (built in the other side of rotation arm). The detected X-ray absorption data is used to process image reconstruction on the Console to create the 3D image (CT scan) and the tomographic image (CT scan, CT-Panoramic scan, Panoramic Scan).
This document is a 510(k) Summary for the PreXion3D Explorer EX, a Computed Tomography X-ray System. It describes the device, its intended use, and its substantial equivalence to a predicate device (PreXion3D Explorer, K190320) and a reference device (PreXion3D Excelsior, K181983).
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not present a formal table of "acceptance criteria" in the sense of specific performance metrics that the device had to achieve for clearance. Instead, it details modifications to a predicate device and then states that system tests and imaging performance tests were conducted to confirm the validity and diagnostic quality of these modifications, ensuring compliance with relevant standards.
The closest to "acceptance criteria" are the standards the device complies with, and the "reported device performance" is the confirmation that it passed these tests or was deemed equivalent.
| Feature / Aspect | Acceptance Criteria (Implicit from Standards/Confirmation) | Reported Device Performance (as stated in the document) |
|---|---|---|
| Biocompatibility | Safe materials (ISO 10993-1, -5, -10) | Confirmed safe, uses same materials as marketed device (PreXion3D Excelsior). Passed relevant ISO standards. |
| Touch Panel/Mirror | Not affecting product safety and performance; electrical safety (IEC60601-1); acceptable risk management for mirror. | IEC60601-1 test performed by qualified lab; risk management performed and mirror decided acceptable. |
| Modified FOV (15 x 8 to 15 x 10) | Validity of new FOV. | System test performed to confirm validity. |
| Added FOV (10 x 10) | Validity of new FOV. | System test performed to confirm validity. |
| Added Panoramic Scan Function | Compliance with imaging performance standard (IEC61223-3-4). | Imaging performance test performed and confirmed to comply with IEC61223-3-4. |
| Detector's effective area change (smaller by 1.5mm) | Retention of diagnostic quality. | An American board-certified radiologist confirmed diagnostic quality. |
| Disabled Cephalometric Scan Function | System validity with this function disabled. | System test performed to confirm validity. |
| General Safety (Electrical, Electromagnetic, Radiation, Usability, Software, etc.) | Compliance with various IEC, ANSI/AAMI, ISO, and NEMA standards (e.g., IEC 60601-1, IEC 60601-1-2, IEC 60601-1-3, IEC 60601-1-6, IEC 62366-1, IEC 62304, ISO 14971, NEMA PS 3.1 - 3.20). | Passed all testing in accordance with internal requirements, national standards, and international standards. |
| Cybersecurity | Collect cybersecurity information and report breaches. | No cyber security threat found as of Oct 2019; no cyber breach reported by customers of predicate device as of Nov 2019. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document focuses on non-clinical performance data and a "substantial equivalence" argument rather than clinical or AI algorithm performance studies with defined test sets.
- Sample size: Not applicable in the context of typical AI algorithm test sets. The "sample" referred to here are individual modifications to the device and the associated technical tests.
- Data provenance: Not explicitly stated as "data provenance" for a test set. The document refers to internal requirements and compliance with international/national standards, suggesting in-house testing or third-party laboratory testing. The radiologist who confirmed diagnostic quality for the detector change is described as "American board-certified," implying a U.S. context for that specific assessment. The cybersecurity information for the predicate device mentions six units installed in the US.
- Retrospective or prospective: Not applicable. These are verification and validation activities for device modifications, not a study on an AI algorithm's performance on a dataset of patient cases.
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)
Only one expert is explicitly mentioned for a specific aspect:
- Number of experts: One.
- Qualifications: "An American board-certified radiologist." No information on years of experience is provided.
- Role: Confirmed that images with the detector modification retained "diagnostic quality." This serves as a form of expert assessment for a specific technical change, rather than establishing ground truth for a test set in an AI study.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. The document describes engineering and performance tests for hardware and software modifications, not a review of clinical cases by multiple experts. The single expert review mentioned for the detector change does not involve an adjudication method as there wasn't a panel.
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 MRMC comparative effectiveness study was done. The device is a Computed Tomography (CT) X-ray system, not an AI-powered diagnostic aide. The document only references "diagnostic support" as the general purpose of the imaging system. There is no mention of AI capabilities or human reader improvement with AI assistance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This device is an imaging system, not an AI algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the specific point where an expert was involved (detector's effective area change), the "ground truth" was the expert opinion of an American board-certified radiologist confirming "diagnostic quality." This is not a clinical ground truth like pathology for specific disease detection but an assessment of image quality for diagnostic purposes. For other technical aspects, the "ground truth" was primarily compliance with established national and international standards.
8. The sample size for the training set
Not applicable. The document describes a medical imaging device (hardware and software), not an AI algorithm that requires a training set.
9. How the ground truth for the training set was established
Not applicable, as there is no training set mentioned for an AI algorithm.
§ 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.