(188 days)
EXPD 114, EXPD 114P, EXPD 114G, EXPD 114PG Digital X-ray detector is indicated for digital imaging solution designed for providing general radiographic diagnosis of human anatomy. This device is intended to replace film or screen based radiographic systems in all general purpose diagnostic procedures. This device is not intended for mammography applications. It is intended for both adult and pediatric populations.
EXPD 114, EXPD 114G, EXPD 114P, EXPD 114PG are flat-panel type digital X-ray detector that captures projection radiographic images in digital format within seconds, eliminating the need for an entire x-ray film or an image plate as an image capture medium. EXPD 114, EXPD 114G, EXPD 114P, EXPD 114PG differs from traditional X-ray systems in that, instead of exposing a film and chemically processing it to create a hard copy image, a device called a Detector is used to capture the image in electronic form.
EXPD 114, EXPD 114G, EXPD 114P, EXPD 114PG are indirect conversion devices in the form of a square plate in which converts the incoming X-rays into visible light. This visible light is then collected by an optical sensor, which generates an electric charges representation of the spatial distribution of the incoming X-ray quanta.
The charges are converted to a modulated electrical signal thin film transistors. The amplified signal is converted to a voltage signal and is then converted from an analog to digital signal which can be transmitted to a viewed image print out, transmitted to remote viewing or stored as an electronic data file for later viewing.
The DRTECH Corporation's EXPD 114, EXPD 114G, EXPD 114P, EXPD 114PG Digital X-ray detectors were assessed for substantial equivalence to a predicate device (K223124). The company conducted non-clinical performance testing (bench tests) and a "Concurrence Study" for image quality to demonstrate this.
Here's a breakdown of the requested information based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a numerical or pass/fail format for the Concurrence Study beyond broad equivalence. Instead, it compares the performance of the subject device to the predicate device. The performance data mentioned primarily relates to technical specifications and general image quality assessment.
| Parameter | Acceptance Criteria (Implied: Equivalent to or comparable to predicate) | Reported Device Performance (Subject Device) | Reported Predicate Device Performance (K223124) |
|---|---|---|---|
| DQE | Equivalent to or comparable to predicate | EXPD 114: 45% @0.5lp/mm | |
| EXPD 114G: 25% @0.5lp/mm | |||
| EXPD 114P: 45% @0.5lp/mm | |||
| EXPD 114PG: 25% @0.5lp/mm | EXPD 129P, EXPD 86P: 50.0 % at 0.5 lp/mm | ||
| EXPD 129PG, EXPD 86PG: 25.0 % at 0.5 lp/mm | |||
| MTF | Equivalent to or comparable to predicate | EXPD 114: 40% @2.0lp/mm | |
| EXPD 114G: 40% @2.0lp/mm | |||
| EXPD 114P: 40% @2.0lp/mm | |||
| EXPD 114PG: 40% @2.0lp/mm | EXPD 129P, EXPD 86P: 45.0 % at 2.0 lp/mm | ||
| EXPD 129PG, EXPD 86PG: 45.0 % at 2.0 lp/mm | |||
| Resolution | Equivalent to or comparable to predicate | 3.5 lp/mm | 3.5 lp/mm |
| Image Quality (Clinical Assessment) | Equivalent to predicate device. | "the image quality of the subject device is equivalent to that of the predicate device" | Standard established by predicate device. |
Note on DQE and MTF: The subject device's DQE for EXPD 114/P is slightly lower than the predicate EXPD 129P/86P (45% vs 50%). Similarly, the MTF for all subject devices is lower than the predicate (40% vs 45%). Despite these numerical differences, the overall conclusion states "basically equal or worth the predicate device" and that the device meets acceptance criteria. This suggests that the measured differences were considered clinically acceptable within the context of substantial equivalence.
2. Sample Size Used for the Test Set and Data Provenance
The document states: "Our Concurrence Study for Image Quality was based on body parts (Chest, C-spine AP, L-spine AP, Shoulder AP, Pelvis AP, Extremity) to compare subject device and predicate device(K223124)."
- Sample Size: The exact number of images or cases analyzed in the Concurrence Study is not specified in the provided text. It only lists the anatomical sites included.
- Data Provenance: The document does not specify the country of origin of the data or whether the study was retrospective or prospective. It is a "Concurrence Study" which implies a direct comparison, likely of newly acquired images, but this is not explicitly stated.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Number of Experts: "a qualified clinical expert" (singular) is mentioned.
- Qualifications of Experts: The expert is described as "qualified clinical expert." No further details on their specific qualifications (e.g., radiologist, years of experience, board certification) are provided.
4. Adjudication Method for the Test Set
- Adjudication Method: The document only mentions "a qualified clinical expert confirmed" the image quality. This strongly suggests a single-reader assessment without any explicit adjudication method (e.g., 2+1, 3+1 consensus).
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- MRMC Study: Based on the description of "a qualified clinical expert confirmed," it appears that a formal MRMC comparative effectiveness study was not conducted. The assessment seems to be a qualitative comparison of image quality by a single expert.
- Effect Size of Human Reader Improvement: As an MRMC study was not indicated, there is no information on the effect size of how much human readers improve with AI vs. without AI assistance. The device is a digital X-ray detector, not an AI software intended for interpretation assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- The device is a digital X-ray detector, not an AI algorithm. Therefore, the concept of "standalone performance" of an AI algorithm is not applicable in this context. The "performance" described relates to the physical characteristics of the detector (DQE, MTF, Resolution) and its ability to produce images of diagnostic quality.
7. Type of Ground Truth Used
- Type of Ground Truth: The ground truth for the Concurrence Study was based on the expert's subjective assessment of image quality compared to the predicate device, stating that "the image quality of the subject device is equivalent to that of the predicate device." This is a form of expert consensus, albeit with only one expert explicitly mentioned. It's not based on pathology or outcomes data.
8. Sample Size for the Training Set
- The document describes a device (digital X-ray detector), not a machine learning model. Therefore, the concept of a "training set" in the context of an AI/ML algorithm is not applicable.
9. How the Ground Truth for the Training Set Was Established
- As the device is not an AI/ML algorithm, the concept of "training set ground truth" is not applicable.
§ 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.