(215 days)
The EXPD 4343S Digital X-ray detector is indicated for use in generating radiographic images of human anatomy. This device is intended to replace film or screen based radiographic systems in all general purpose diagnostic procedures on general populations. This device is not intended for mammography applications.
The EXPD 4343S Detector is a square plate-shaped indirect conversion device that converts incoming X-rays into visible light. This visible light is subsequently captured by an optical sensor, which produces an electric charge representation of the spatial distribution of the incoming X-ray quanta. Through thin film transistors, the charges are transformed into a modulated electrical signal is amplified, then changed from an analog to digital form (from voltage to signal) so that it can be printed out, sent for remote viewing, or saved as an electronic data file for later viewing. The subject device features two matrix arrays strategically positioned in an overlapping configuration within the housing, facilitating the generation of multiple images with a single exposure. Array #1 works similarly to the predicate device by detecting incident X-ray photons and converting them into electrical signals. Simultaneously, Array #2 captures unabsorbed X-rays from Array #1 after passing through it. As a consequence of this configuration, the subject device has the capacity to produce three distinct images: a Standard image produced by Array #1, a second image (a soft tissue image) obtained by processing the Standard image using Console software, and a third image (a bone image) generated by processing the image obtained from Array #2.
The provided text describes a 510(k) summary for the EXPD 4343S Digital X-ray detector, claiming substantial equivalence to a predicate device (EXPD 4343P). However, the document does not contain specific acceptance criteria or a detailed study proving the device meets those criteria with quantitative values.
Instead, it presents a comparison of technological characteristics and states that:
- "an overall assessment of the subject device's essential performance revealed that it is basically on the equivalent level with the predicate device."
- "the clinical image evaluation was performed to assess the device's clinical performance and average score of evaluation results by two experienced physicians demonstrated that the device is prove to be effective in clinical practice."
- "The result showed that images acquired by the subject device were generally in diagnostic quality, and evaluators stated that the device proved to be effective use in clinical practice."
Without specific numerical acceptance criteria and a structured study result, it's impossible to fill out the requested table and answer many of the specific questions.
Based on the information available, here's what can be extracted and what remains unknown:
Acceptance Criteria and Device Performance (Based on available comparative data)
While no explicit acceptance criteria are provided in the sense of pass/fail thresholds, the document implies that the device's performance is deemed acceptable if it is "basically on the equivalent level" to the predicate device and found to be "effective in clinical practice" and "of diagnostic quality" by physicians.
| Criteria (Implied/Compared) | Subject Device (EXPD 4343S) | Predicate Device (EXPD 4343P) |
|---|---|---|
| Modulation Transfer Function (MTF) | 45 % at 2.0 lp/mm | 52 % at 2.0 lp/mm |
| Detective Quantum Efficiency (DQE) | 55 % at 0.5 lp/mm | 55 % at 0.5 lp/mm |
| Clinical Image Quality | Evaluated by two experienced physicians; images "generally in diagnostic quality" and "effective in clinical practice." | (No specific clinical performance data for predicate provided, but implied as the comparable standard.) |
| Electrical Safety | Meets IEC 60601-1 requirements | (Implied to meet similar standards as part of predicate clearance) |
| Electromagnetic Compatibility | Meets IEC 60601-1-2 requirements | (Implied to meet similar standards as part of predicate clearance) |
Study Details (Inferred and Missing Information)
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Sample size used for the test set and the data provenance:
- Sample Size: Not specified. The document states "Chest PA imaging sets used for evaluation".
- Data Provenance: Not specified (e.g., country of origin, retrospective/prospective). It just mentions "Chest PA imaging sets".
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Number of Experts: Two experienced physicians.
- Qualifications: "experienced physicians." No further detail regarding their specialty (e.g., radiologist) or years of experience is provided.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Adjudication Method: Not specified. It mentions an "average score of evaluation results" and that "visual system was adapted with each physician's overall assessment," which suggests independent assessment followed by some form of averaging or consensus, but the specific method is not detailed.
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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:
- MRMC Study: No, an MRMC study was not conducted as described for AI assistance. The study described is a clinical image evaluation of the device's output by physicians, not an evaluation of AI assistance to human readers. The device itself is an X-ray detector, not an AI diagnostic tool.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Standalone Performance: Not applicable in the context of an X-ray detector's primary performance. The "soft tissue image" and "bone image" are generated by processing, which implies an algorithm, but the performance evaluation described is of the final image quality and diagnostic effectiveness by human readers. There is no mention of a quantitative standalone performance evaluation of these derived images in terms of specific diagnostic tasks.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Ground Truth: Expert assessment/consensus from the two experienced physicians on the "diagnostic quality" and "effectiveness in clinical practice" of the images generated by the device. It is not based on pathology or outcomes data.
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The sample size for the training set:
- Training Set Sample Size: Not applicable. This document is for an X-ray detector, not an AI algorithm that requires a training set. The "soft tissue" and "bone" image processing is fundamental to the detector's output, not a separate AI application.
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How the ground truth for the training set was established:
- Training Set Ground Truth: Not applicable, as no training set for an AI algorithm is mentioned.
Summary of what's provided vs. what's missing:
The document provides basic comparative technical specifications and a high-level qualitative summary of a clinical image evaluation. It lacks detailed quantitative results, specific acceptance criteria for image quality, detailed expert qualifications, sample sizes, and adjudication methods that would be expected in a rigorous study for an AI-enabled diagnostic device. Given that the device is a digital X-ray detector, the focus of the provided information is on demonstrating the equivalence of its imaging capabilities to a predicate device, rather than the performance of a diagnostic AI algorithm.
§ 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.