(11 days)
The DIGITAL RADIOGRAPHY CXDI-Elite / E1 provides digital image capture for conventional film/screen radiographic examinations. This device is intended to capture, for display, radiographic images of human anatomy, and to replace radiographic film/screen systems in all general purpose diagnostic procedures. This device is not intended for mammography applications.
The DIGITAL RADIOGRAPHY CXDI-Elite, also called the DIGITAL RADIOGRAPHY E1, (hereinafter referred to as CXDI-Elite) is a solid-state x-ray imager. The CXDI-Elite is a series of detectors, and in the predicate device consists of the CXDI-720C Wireless detector unit, also called the AR-E3543W detector. The detector intercepts x-ray photons, and the scintillator emits visible spectrum photons that illuminate an array of photodetectors that create electrical signals. After the electrical signals are generated, the signals are converted to digital values, and the images will be displayed on monitors. The digital value can be communicated to the operator console via a wired or wireless connection.
The subject of this Special 510(k) submission is a change to the CXDI-Elite to add new detectors, the CXDI-420C Wireless (also called AR-E4343W) and the CXDI-420C Fixed (also called AR-E4343S), to the CXDI-Elite series of detectors. In addition, a Detector Stand (DS-01) has also been added as a component to be used with both the CXDI-720C Wireless and CXDI-420C Wireless. Compatibility with the Power Box (PB-01), a CXDI-Pro component that was cleared under K220098 has also been added. The CXDI Control Software has been updated from V3.10.0.4 to V3.10.2.2 to fix some bugs, update the GPU driver, and add several minor functional changes. Together, these changes make up the CXDI-Elite.
Upon review of the provided document, it is important to note that the submission is for an imaging device (Digital Radiography CXDI-Elite / E1), not an AI/Software as a Medical Device (SaMD) that performs diagnostic or assistive functions requiring performance studies with acceptance criteria based on accuracy metrics.
The document primarily addresses a Special 510(k) submission for changes to an existing, cleared device. These changes involve adding new detectors, an optional accessory, and software bug fixes/minor functional changes. Therefore, the "acceptance criteria" and "study that proves the device meets the acceptance criteria" in this context refer to engineering and safety performance, rather than clinical efficacy measured by AI model output and human reader performance.
The provided text does not contain information about:
- A table of acceptance criteria and reported device performance related to diagnostic accuracy.
- Sample sizes for test sets (in the context of clinical performance evaluation).
- Data provenance (country of origin, retrospective/prospective).
- Number of experts for ground truth establishment or their qualifications.
- Adjudication methods.
- Multi-Reader Multi-Case (MRMC) comparative effectiveness studies.
- Standalone algorithm performance studies.
- Types of ground truth (expert consensus, pathology, outcomes data).
- Sample size for training sets.
- How ground truth for training sets was established.
Instead, the document focuses on demonstrating substantial equivalence to a predicate device by confirming that the modifications do not raise new questions of safety or effectiveness. This is primarily achieved through non-clinical/bench testing and adherence to relevant standards.
Here's a summary of what the document does provide regarding acceptance criteria and performance, as it pertains to the hardware and basic software functionality of a digital radiography system:
Acceptance Criteria and Study for Digital Radiography CXDI-Elite / E1 (Hardware/Software Updates)
The acceptance criteria are implicitly met by demonstrating continued compliance with relevant international and FDA standards, and by showing that the changes (new detectors, accessory, software update) do not negatively impact the fundamental performance or safety characteristics of the device.
1. Table of Acceptance Criteria (Implicit) and Reported Device Performance (as stated in the document):
| Acceptance Criteria (Implicit/Standard Compliance) | Reported Device Performance (as per "Summary of Non-Clinical / Test Data") |
|---|---|
| Fundamental Scientific Technology Unchanged | "The fundamental scientific technology of the CXDI-Elite has not been modified." |
| Conformance with U.S. Performance Standard for Radiographic Equipment | "Evaluation of the addition of the new detector and optional accessories confirmed that the changes did not impact CXDI-Elite conformance with the U.S. Performance Standard for radiographic equipment..." |
| Compliance with Voluntary Safety Standards (Electrical Safety, EMC) | "...and with relevant voluntary safety standards for Electrical safety and Electromagnetic Compatibility testing, specifically IEC standards 60601-1, 60601-1-2, 60601-2-54, and 60601-1-6." |
| Device Works as Intended (Functional Performance) | "Adequate detector bench testing should be sufficient to demonstrate that the subject detector CXDI-Elite / E1 works as intended." (This indicates bench testing was done to verify the new components and software perform correctly within the system.) |
| No New Questions Regarding Safety or Effectiveness Compared to Predicate | "These verification/validation activities successfully demonstrated that the device continues to meet the standards for the areas impacted by the modifications to the predicate device and raises no new questions regarding either safety or effectiveness when compared to the predicate device." |
| Pixel Pitch | 125μm (Identical to predicate) |
| Scintillator | CsI(Tl) [Cesium Iodide doped with Thallium] (Identical to predicate) |
| Spatial Resolution | 45% [MTF@2lp/mm] (Identical to predicate) |
| DQE (Detective Quantum Efficiency) | 67% [@0.5 lp/mm, 3.5 uGy] (Identical to predicate) |
| IP Level (Ingress Protection) | CXDI-720C Wireless: IP57, CXDI-420C Wireless: IP57, CXDI-420C Fixed: N/A (Modified from predicate, detailed for each new component) |
| Wireless Communication | IEEE 802.11a/b/g/n/ac, 2.4GHz/5GHz, Bluetooth Low Energy (only for CXDI-720C Wireless and CXDI-420C Wireless) (Identical to predicate's wireless capabilities) |
| External Dimensions | CXDI-720C Wireless: 384 x 460 x 15.5 mm, CXDI-420C Wireless: 460 x 460 x 15.5 mm, CXDI-420C Fixed: 460 x 460 x 15.3 mm (Modified from predicate, detailed for each new component) |
| Photographing Mode (Functional Modes of Operation) | Standard Synchronization Mode, Standard Synchronization Mode with Built in AEC Assistance, Non Generator Connection Mode, Standalone Mode (only for CXDI-720C Wireless and CXDI-420C Wireless) (Modified from predicate to reflect modes available with new detectors; one mode removed for fixed detector) |
| Compliance with Applicable FDA Guidance Documents | The proposed device follows applicable elements of several FDA guidance documents (e.g., Guidance for the Submission of 510(k)s for Solid State X-ray Imaging Devices, Content of Premarket Submissions for Management of Cybersecurity in Medical Devices, etc.) |
2. Sample Size Used for the Test Set and Data Provenance:
- The document states "Adequate detector bench testing should be sufficient to demonstrate that the subject detector CXDI-Elite / E1 works as intended." This implies physical testing of the devices, but does not specify sample sizes for "test sets" in the clinical performance sense, as this was not a clinical performance study. The testing appears to be primarily engineering verification and validation of hardware and software components.
- Data provenance: Not applicable in the context of clinical images or patient data. The testing is a validation of the device's technical specifications and compliance.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts:
- Not applicable. This was not a study requiring expert readers to establish ground truth on clinical images, as it was not a diagnostic performance study for an AI algorithm.
4. Adjudication Method for the Test Set:
- Not applicable for the reasons stated above.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and what was the effect size of how much human readers improve with AI vs without AI assistance:
- No. This was not an AI-enabled diagnostic device or a comparative effectiveness study involving human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- No. This device is a digital radiography system, not a standalone AI algorithm. Its function is to capture and display radiographic images.
7. The Type of Ground Truth Used:
- Not applicable in the clinical diagnostic sense. The "ground truth" for this submission are the established engineering specifications, safety standards (IEC 60601 series), and FDA guidance documents, against which the device's technical performance (e.g., MTF, DQE, IP level, functional modes) is verified via bench testing.
8. The Sample Size for the Training Set:
- Not applicable. This device does not involve machine learning or AI models with training sets.
9. How the Ground Truth for the Training Set was Established:
- Not applicable for the reasons stated above.
In conclusion, the provided document is a 510(k) summary for a digital radiography hardware system with minor modifications. The "acceptance criteria" and "study" described pertain to engineering validation, safety testing, and demonstration of substantial equivalence by showing that the updated device continues to meet established performance and safety standards, and does not pose new risks. It is not an AI/SaMD performance study seeking to establish diagnostic accuracy against clinical ground truth.
§ 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.