(263 days)
3D-SHAPER uses data from conventional Dual Energy X-Ray Absorptiometry (DXA) scans to measure the distribution of bone mineral mass at specific cross sections of the hip and allows the physician to estimate structural properties of the hip, such as CSA, CSMI, Z, Buckling Ratio, cortical sBMD, trabecular vBMD and integral vBMD.
3D-SHAPER is indicated to be used by qualified medical professionals to assist healthcare professionals in the bone health evaluation & changes, and cannot fully substitute their clinical judgement.
3D-SHAPER is a software reconstructing in 3D, the shape and bone mineral density from 2D DXA images. The software incorporates a DXA-based 3D reconstruction and measures the distribution of bone mineral mass at specific cross sections of the hip. It provides physicians with estimates of the structural properties of the hip, such as densities or geometrical parameters. The software is not suitable for use with paediatric patients or for subjects with hip prosthesis such as total hip replacement prosthesis, hip resurfacing prosthesis or an osteosynthesis system, since the software has not been tested against these conditions. 3D-SHAPER is indicated to be used by qualified medical professionals to assist healthcare professionals in the bone health evaluation & changes, and cannot fully substitute their clinical judgement.
The 3D-SHAPER® measurements include:
Cortical surface Bone Mineral Density (Cortical sBMD, mg/cm2)
Trabecular volumetric Bone Mineral Density (Trabecular vBMD, mg/cm³)
Integral volumetric Bone Mineral Density (Integral vBMD, mg/cm³), the integral compartment being the union of the cortical and trabecular compartments.
Hip structural measurements: Cross-Sectional Area (CSA, in cm²), Cross-Sectional Moment of Inertia (CSMI, in cm4), section modulus (Z, in cm3) and buckling Ratio (BR).
Cortical sBMD, trabecular VBMD and integral vBMD are calculated at the total femur. CSA, CSMI, Z and BR are calculated in cross-sections at the neck, intertrochanteric region and lower shaft.
Here's a breakdown of the acceptance criteria and study information for the 3D-SHAPER device, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance:
The document primarily focuses on demonstrating substantial equivalence to a predicate device through correlation studies rather than establishing absolute performance metrics against predefined acceptance criteria for each measurement. However, it does outline the type of performance expected in the "Performance Bench Testing" section.
| Feature/Metric | Acceptance Criteria (Implied by correlation values) | Reported Device Performance (Correlation to QCT) |
|---|---|---|
| Integral vBMD | Very strong correlation (r ≥ 0.9) | r = 0.96 |
| Cortical sBMD | Very strong correlation (r ≥ 0.9) | r = 0.95 |
| Trabecular vBMD | Very strong correlation (r ≥ 0.9) | r = 0.93 |
| CSA | Very strong correlation (r ≥ 0.95) | r ≥ 0.95 |
| CSMI | Very strong correlation (r ≥ 0.92) | r ≥ 0.92 |
| Z | Very strong correlation (r ≥ 0.91) | r ≥ 0.91 |
| Buckling Ratio (BR) | Strong correlation (r ≥ 0.7) | r ≥ 0.71 |
| Computing time | Not explicitly stated as a target | Lower than 2 minutes and 30 seconds |
| Software convergence | Not explicitly stated as a target | Superior to 95% |
2. Sample Size Used for the Test Set and Data Provenance:
The document mentions two main studies:
- Correlation Study with Predicate Device:
- Sample Size: 740 men and women (94% women).
- Data Provenance: Not explicitly stated (e.g., country of origin). The study is retrospective in the sense that existing DXA scans were analyzed by both the 3D-SHAPER and the predicate device.
- Performance Bench Testing (Correlation to QCT):
- Sample Size: Not explicitly stated for this particular correlation study with QCT. It refers to "subject-specific models of the femoral shape and measurements compared to Quantitative Computed Tomography (QCT)." This implies data from human subjects but the exact number isn't provided.
- Data Provenance: Not explicitly stated. Likely retrospective, as it compares measurements to an established imaging modality (QCT).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
- Correlation Study with Predicate Device: Ground truth for this study was the measurements produced by the predicate device (Hologic Hip Structural Analysis software, K061561). No human experts were involved in establishing this specific ground truth; it relied on a previously cleared, validated software.
- Performance Bench Testing (Correlation to QCT): Ground truth was established by Quantitative Computed Tomography (QCT) measurements. QCT is a quantitative imaging technique that provides volumetric bone mineral density and structural information. No human experts are described as manually establishing this ground truth; it's a direct comparison to QCT output.
4. Adjudication Method:
- Correlation Study with Predicate Device: There was no adjudication method described. The study compared the output of the 3D-SHAPER software directly against the output of the predicate device.
- Performance Bench Testing (Correlation to QCT): There was no adjudication method described. The study compared the output of the 3D-SHAPER software directly against QCT measurements.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The study described focuses on the comparison of the 3D-SHAPER software's measurements against a predicate software and against QCT, not on how human readers' performance improves with or without AI assistance.
6. Standalone Performance:
Yes, a standalone performance study (algorithm only without human-in-the-loop) was done. The document consistently describes the 3D-SHAPER software's ability to measure structural properties from DXA scans and correlates these measurements with a predicate device and QCT. This is considered standalone performance.
7. Type of Ground Truth Used:
- Correlation Study with Predicate Device: The ground truth was the output of a legally marketed predicate device (Hologic Hip Structural Analysis software).
- Performance Bench Testing (Correlation to QCT): The ground truth was Quantitative Computed Tomography (QCT) measurements.
8. Sample Size for the Training Set:
The document does not provide any information regarding the sample size used for the training set. It focuses on the validation of the device.
9. How the Ground Truth for the Training Set Was Established:
The document does not provide any information on how the ground truth for the training set was established, as the training process itself is not detailed.
§ 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.