(25 days)
X-ray Bone Densitometer designed to estimate the bone mineral density of patients when medically indicated by their physicians.
- Provides an estimate of bone mineral density at various anatomical sites (Spine, Femur, Forearm). These values can then be compared to an adult reference population at the sole discretion of the physician.
- Provides an assessment of relative risk based on the patient's T-score value using the categories of fracture risk defined by the World Health Organization (WHO).
- Provides an assessment of 10-year fracture risk using WHO FRAX model.
- Provides a standardized bone density report using data from the densitometer and physician-generated assessments based on the patient's demographics, which can assist the physician in communicating scan results to the patient and the patient's referring physician.
The Aria X-ray Bone Densitometer is designed to be a value product version of the predicate device, the Prodigy (K982267 and K161682). Like its predicate Prodigy device, the proposed Aria device is composed of a scanner and a computer that runs the software. The scanner comprises the x-ray source and detector, the patient scan table, the mechanical drive system, and the lowest level portions of the control system. The scanner is in communication with the computer, which is a standard PC. The computer runs the enCORE software, and thus controls the scanner, acquires scan data from the scanner, stores and analyzes the data, and interacts with the human operator.
Aria X-ray Bone Densitometer functions with the same software as the one that is FDA cleared under GE Lunar DXA Bone Densitometers with enCORE version 17 (K161682).
Here's a breakdown of the acceptance criteria and the study conducted for the Aria device, based on the provided text:
Based on the provided information, the Aria device is an X-ray Bone Densitometer. The study presented is a bench testing to demonstrate precision and accuracy, not a clinical study involving human subjects or AI algorithms. As such, several requested items like "Multi-reader multi-case (MRMC) comparative effectiveness study" and "Human reader improve with AI vs without AI assistance" are not applicable.
1. Table of Acceptance Criteria and Reported Device Performance
| Measure | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Precision | 0.95 | Met (demonstrated in results) |
2. Sample Size and Data Provenance for the Test Set
- Sample Size: The text mentions "a wide range of phantoms" for precision and accuracy tests, and "a set of phantoms with different BMD and tissue composition properties." However, specific numerical sample sizes for these phantom sets are not provided.
- Data Provenance: The tests were conducted during "product development" as "bench testing." The data provenance is from phantom measurements, not human participants. No country of origin is explicitly stated for the phantom data, but it's implied to be internal testing by GE Healthcare (USA). The study is retrospective in the sense that it's based on controlled phantom measurements rather than prospective patient recruitment.
3. Number of Experts and Qualifications for Ground Truth
- Not applicable. The ground truth for the test set was established using phantoms with known bone mineral density (BMD) and tissue composition properties, not by human experts. The accuracy was verified by showing an "excellent correlation to previously released Prodigy product," implying a comparison to an established device's performance.
4. Adjudication Method for the Test Set
- Not applicable. Since the ground truth was phantom-based and not expert-driven, there was no adjudication method involving multiple experts.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The presented study is a bench test, and the device is a bone densitometer, not an AI-assisted diagnostic tool for human interpretation. Therefore, there's no "effect size of how much human readers improve with AI vs without AI assistance" to report.
6. Standalone (Algorithm Only) Performance Study
- Yes, a standalone performance study was done. The precision and accuracy bench testing evaluates the algorithm's (and the overall device's) ability to accurately and precisely estimate bone density from phantom measurements without human intervention in the measurement process. The results "demonstrate that Aria can accurately and precisely estimate bone density."
7. Type of Ground Truth Used
- The ground truth used was phantom-based with established, known values for bone mineral density (BMD) and tissue composition properties. These values were validated against the performance of the predicate Prodigy product.
8. Sample Size for the Training Set
- Not explicitly stated and likely not applicable in the traditional sense for a machine learning model. The Aria device is presented as a "value product version" using the "same software as the one that is FDA cleared under GE Lunar DXA Bone Densitometers with enCORE version 17 (K161682)." This suggests that the core algorithms might have been developed and "trained" (if applicable for this type of system) with data associated with the enCORE software, but the document does not provide details on a specific training set size for Aria's development.
9. How the Ground Truth for the Training Set was Established
- Not explicitly stated and likely not applicable in the traditional sense for a machine learning model. Given that the Aria uses the same software (enCORE v17) as its predicate, the ground truth for any underlying algorithm "training" would have been established during the development of that software. Typically for bone densitometry, this involves:
- Phantom studies: Similar to the testing described, using phantoms with known physical properties.
- Clinical studies: Correlating device measurements against other established methods or clinical outcomes, although this document states clinical studies were "not required" for Aria's substantial equivalence.
§ 892.1170 Bone densitometer.
(a)
Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.