(190 days)
The WeSensor is used for a radiographic examination by a dental professional to assist in the diagnosing of diseases of the teeth, jaw and oral structures.
The WeSensor is an intraoral digital x-ray sensor. It comprises three components: (1) an intraoral digital X-ray sensor which connects to a PC via a USB port; (2) WeSensor Software package; and (3) a sensor holder as an accessory.
The provided text describes the WeSensor, an intraoral digital X-ray sensor, and its clearance by the FDA based on substantial equivalence to predicate devices. The document contains information relevant to performance data and comparison with predicate devices, but it does not contain a detailed formal study report with specific acceptance criteria and detailed performance of the WeSensor against those criteria.
However, it does state "The successful test results including max.image resolution, DQE, and MTF indicate that the subject device performance is comparable to or exceed those of the predicate devices." and "clinical images were examined by Dr.Park, a qualified dentist in the state of Nevada. The results demonstrated no significant difference in diagnosing dental diseases between the subject device and the predicate device."
Based on the information available, here's an attempt to structure the answer, acknowledging the limitations for certain points where specific details are not provided:
Acceptance Criteria and Device Performance (Inferred from Predicate Comparison)
The document primarily relies on "substantial equivalence" to predicate devices rather than pre-defined acceptance criteria based on numerical thresholds. The acceptance criteria are implicitly met by demonstrating that the WeSensor's performance characteristics are "comparable to or exceed" those of the predicate devices.
Table of Performance Characteristics (Implied Acceptance Criteria = Comparable/Exceed Predicate)
| Characteristic | WeSensor Reported Performance | Predicate (QuickRay HD) Performance | Implied Acceptance |
|---|---|---|---|
| Max. Image Resolution (lp/mm) | G150A & G350A: 14.3; F150A & F350A: 16.6 | ≥ 20 lp/mm | Performance must be comparable to or exceed predicate. (WeSensor's values are lower than the predicate listed, suggesting this might be a point of similarity despite the "exceed" statement elsewhere in the text, or a specific model of the predicate may vary.) |
| DQE | 0.464 at 0 lp/mm; 0.060 at 6 lp/mm | 0.45 at 0 lp/mm; 0.16 at 6 lp/mm | Performance must be comparable to or exceed predicate. (WeSensor's DQE at 0 lp/mm is slightly higher, but lower at 6 lp/mm, implying comparability across properties.) |
| MTF | 0.594 at 3 lp/mm; 0.1 at 13 lp/mm | 0.65 at 3 lp/mm; 0.09 at 13 lp/mm | Performance must be comparable to or exceed predicate. (WeSensor's MTF at 3 lp/mm is slightly lower, but higher at 13 lp/mm, implying comparability across properties.) |
| Pixel Size | 20 × 20µm | 20 × 20µm | Identical to predicate. |
| Gray Levels | 14 bits | 14 bits | Identical to predicate. |
| Clinical Diagnostic Performance | "no significant difference in diagnosing dental diseases" vs. predicate | Established by predicate device | Clinical performance must demonstrate non-inferiority/comparability to predicate. |
Study Details
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Sample Size and Data Provenance for Test Set:
- Sample Size: The document does not explicitly state the sample size used for the clinical image examination or the performance testing (max. image resolution, DQE, MTF).
- Data Provenance: The document states that "clinical images were examined by Dr. Park, a qualified dentist in the state of Nevada." This suggests the clinical images were likely generated prospectively or collected for this specific evaluation, and the data provenance is the USA (Nevada). It does not specify if the images were retrospective or prospective, only that they "were examined." The technical performance tests (DQE, MTF, resolution) are laboratory-based, not patient-data based.
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Number of Experts and Qualifications for Ground Truth (Test Set):
- Number of Experts: Only one expert is explicitly mentioned: "Dr. Park, a qualified dentist in the state of Nevada."
- Qualifications: "qualified dentist in the state of Nevada." No specific years of experience or subspecialty certification (beyond general dentistry) are provided.
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Adjudication Method for the Test Set:
- Method: "None" as only one expert ("Dr. Park") is mentioned for the clinical image examination. There is no indication of multiple readers or an adjudication process for clinical ground truth.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- Was it done? No, a formal MRMC study is not described. The clinical evaluation mentioned involves a single dentist's comparison of images for diagnostic equivalence, not an assessment of human reader improvement with or without AI assistance.
- Effect Size: Not applicable, as an MRMC study was not stated to be performed.
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Standalone Performance (Algorithm Only):
- Was it done? The WeSensor is an intraoral digital X-ray sensor, a hardware device that captures images. The "WeSensor Software package" is mentioned, and it performs "acquisition, storage, transmission along with simple editing functions." It does not appear to be an AI algorithm for diagnostic interpretation. Therefore, a standalone algorithm-only performance study (e.g., for AI interpretation) is not relevant or described. The clinical evaluation described evaluates the device's ability to produce images suitable for human diagnosis.
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Type of Ground Truth Used:
- For Clinical Images: "Expert consensus" by a single qualified dentist ("Dr. Park") comparing the subject device images to predicate device images for diagnostic equivalence. The document states, "The results demonstrated no significant difference in diagnosing dental diseases between the subject device and the predicate device."
- For Technical Performance: Physical measurements (e.g., lp/mm, DQE, MTF) are used, which are objective quantitative metrics not requiring human ground truth.
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Sample Size for Training Set:
- The document does not describe a "training set" as the WeSensor is a hardware imaging device, not an AI/ML model that requires a data training phase. Its software handles image acquisition and management, not AI-based diagnosis.
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How Ground Truth for Training Set was Established:
- Not applicable as there is no mention of an AI/ML component with a training set.
§ 872.1800 Extraoral source x-ray system.
(a)
Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for dental radiographic examination and diagnosis of diseases of the teeth, jaw, and oral structures. The x-ray source (a tube) is located outside the mouth. This generic type of device may include patient and equipment supports and component parts.(b)
Classification. Class II.