(249 days)
The Bunkerhill BMD Algorithm is a post-processing AI-powered software intended for adults 30 years and above to assess estimated DXA-measured average areal bone mineral density of spinal bones from existing CT scans and outputs a flag for low bone density below a pre-specified threshold. It is not intended to replace DXA or any other tests dedicated to BMD measurement.
Bunkerhill BMD is an opportunistic AI-powered tool that enables:(1) retrospective assessment of bone density from CT scans acquired for other purposes, (2) assessment of bone density in conjunction with another medically appropriate procedure involving CT scans, and (3) assessment of bone density without a phantom as an independent measurement procedure
The Bunkerhill BMD application is a software only medical device (SaMD) that includes deep- learning-based computer vision and post-processing algorithms that estimates the bone mineral density from previously obtained computed tomography (CT) images.
The results from Bunkerhill BMD are not intended to be used as the primary input for clinical decision making, but rather are intended to provide information that may assist the clinician to identify 'findings of interest' within existing imaging studies.
Here's a breakdown of the acceptance criteria and study details for the BunkerHill BMD device, based on the provided FDA 510(k) clearance letter:
Acceptance Criteria and Device Performance Study for BunkerHill BMD
1. Table of Acceptance Criteria and Reported Device Performance
| Metric | Acceptance Criteria | Reported Device Performance (95% Confidence Interval) | Status |
|---|---|---|---|
| Sensitivity | Lower bound > 70% | 81.0% (74.0% - 86.8%) | Pass |
| Specificity | Lower bound > 70% | 78.4% (72.3% - 83.7%) | Pass |
| Pearson Correlation Coefficient | Not explicitly stated, but implicitly supported by "further supporting the robustness and reliability" | 0.791 (0.752–0.830) | N/A (Secondary) |
| AUROC | Not explicitly stated, but implicitly supported by "further supporting the robustness and reliability" | 0.883 (0.849–0.916) | N/A (Secondary) |
| PPV (Positive Predictive Value) | Not explicitly stated, but implicitly supported by "further supporting the robustness and reliability" | 73.6% (66.4%–79.9%) | N/A (Secondary) |
| NPV (Negative Predictive Value) | Not explicitly stated, but implicitly supported by "further supporting the robustness and reliability" | 84.8% (79.0%–89.5%) | N/A (Secondary) |
2. Sample Size and Data Provenance for the Test Set
- Test Set Sample Size: 371 CT studies
- Data Provenance: The studies were collected from four (4) geographically diverse sites. The retrospective nature of the study is explicitly stated ("stand-alone retrospective study").
3. Number of Experts and Qualifications for Ground Truth
The document does not explicitly state the number of experts used to establish the ground truth or their specific qualifications (e.g., "radiologist with 10 years of experience").
4. Adjudication Method for the Test Set
The document does not explicitly state the adjudication method (e.g., 2+1, 3+1, none) used for the test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not reported in the provided text. The study described is a standalone performance evaluation of the algorithm.
6. Standalone Performance Study
Yes, a standalone (algorithm only without human-in-the-loop performance) study was done. The document states: "Bunkerhill BMD performance was validated in a stand-alone retrospective study for overall agreement of the device output compared to the established ground truth."
7. Type of Ground Truth Used
The type of ground truth used is implied to be based on DXA-measured average areal bone mineral density of spinal bones, as the device is intended to "assess estimated DXA-measured average areal bone mineral density." The text refers to "established ground truth" in relation to this assessment.
8. Sample Size for the Training Set
The document does not provide the sample size for the training set. It only describes the test set.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how the ground truth for the training set was established. It only refers to "established ground truth" for the test set evaluation.
§ 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.