(126 days)
The bone density estimates from the Apollo™ can be compared to estimates of young normal Caucasian men and women, and as an aid to physicians in diagnosing and managing osteoporosis. The bone density estimates from the Apollo™ can be used as an aid to physicians in determining fracture risk.
The Norland Apollo™ Bone Densitometer (Apollo™) scans the os calcis (heel) using the industry standard DXA pencil beam technology to assess bone density. A water bath is not required and the scan takes less than 30 seconds. Patient dose is less than 0.5 mRem and scatter radiation is less than 0.1 mRem/hour at 3 feet.
Two reference sets are provided, one for female Caucasians and one for male Caucasians. These reference data sets allow comparison of Apollo™ BMD scan results to healthy young adults aged 20 to 42. The results of the comparison is given in terms of T-Score (the number of standard deviations from the healthy young adult value), % Young Reference (the percentage relative to the healthy young adult value), and in graphical form.
The Apollo™ Reference Population capability also includes Fracture Risk assessment based on the World Health Organization (WHO) criteria. In general, this means that patients with T- Scores from +1 to -1 are considered to be normal; with T-Scores from -1 to -2.5 are considered to have low bone mass and have an increased risk of fracture; and T-Scores below -2.5 are considered to be osteoporotic and have a high risk of fracture.
Other reference data sets will be available in the future.
Here's an analysis of the provided text regarding the Norland Apollo™ Bone Densitometer's reference population capability, structured according to your requested information.
It's important to note that the provided 510(k) summary primarily focuses on establishing substantial equivalence for a reference population capability rather than a device with a specific performance metric like accuracy or sensitivity/specificity against a ground truth. The "device" in this context refers to the software feature that allows the Apollo™ densitometer to compare BMD results against a healthy young adult population. Therefore, typical acceptance criteria that you might expect for a diagnostic algorithm (e.g., AUC, sensitivity, specificity) are not present here. Instead, the "acceptance criteria" are implied by the successful establishment of this reference population.
1. Table of Acceptance Criteria and Reported Device Performance
As noted above, this 510(k) is for a reference population capability, not an algorithm that produces a diagnostic output with typical performance metrics. The "device performance" here relates to the establishment and utilization of reference data.
| Aspect of Capability | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Reference Data | Need for robust, representative data for young normal Caucasians (men and women) aged 20-42. | "Two reference sets are provided, one for female Caucasians and one for male Caucasians. These reference data sets allow comparison of Apollo™ BMD scan results to healthy young adults aged 20 to 42." The document states that the capability is comparable to other bone densitometers in the industry. The specific characteristics of the reference population dataset (e.g., size, inclusion/exclusion criteria beyond age/ethnicity, statistical methodologies used to derive the reference values) are not detailed in this summary. |
| T-Score Calculation | Ability to calculate T-Scores based on the established reference population. | The device "results of the comparison is given in terms of T-Score (the number of standard deviations from the healthy young adult value)." |
| % Young Reference | Ability to calculate % Young Reference. | The device "results of the comparison is given in terms of... % Young Reference (the percentage relative to the healthy young adult value)." |
| Graphical Form | Ability to present comparison results graphically. | The device "results of the comparison is given in terms of... graphical form." |
| Fracture Risk Assessment Integration | Integration of WHO-based fracture risk assessment criteria using T-Scores. | "The Apollo™ Reference Population capability also includes Fracture Risk assessment based on the World Health Organization (WHO) criteria. In general, this means that patients with T- Scores from +1 to -1 are considered to be normal; with T-Scores from -1 to -2.5 are considered to have low bone mass and have an increased risk of fracture; and T-Scores below -2.5 are considered to be osteoporotic and have a high risk of fracture." |
| Safety and Effectiveness | No new safety or effectiveness issues compared to predicate devices. | "The Reference Population capability for the Apollo™ is comparable to reference population capabilities in use with other bone densitometers in the industry. No new safety or effectiveness issues are raised with this capability." This is a general statement rather than a specific performance metric. |
2. Sample Size Used for the Test Set and Data Provenance
The 510(k) summary does not explicitly describe a "test set" or a study designed to evaluate the performance of an algorithm against a specific gold standard using such a set. The document refers to "reference sets" which are effectively population normative data.
- Sample Size: Not specified for the reference sets of young normal Caucasians.
- Data Provenance: Not specified (e.g., country of origin, retrospective/prospective). The data is described as "young normal Caucasian men and women."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the 510(k) summary. Given that the submission is for a reference population capability and not a diagnostic algorithm, the concept of "experts establishing ground truth for a test set" in the traditional sense of evaluating an algorithm's output doesn't directly apply. The "ground truth" would be the derivation of the normative reference values, which typically involves statistical analysis of a healthy population, not individual expert adjudication of cases.
4. Adjudication Method for the Test Set
This information is not provided as there is no described test set that underwent adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study is not mentioned or implied in this 510(k) summary. The context is not an AI-assisted interpretation but rather the provision of normative reference data for bone density measurements.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The "device" here is the software capability to provide reference population comparison, T-Scores, and fracture risk assessment based on WHO criteria. This is a standalone computational function of the densitometer; it doesn't involve human-in-the-loop performance for its core operation. The densitometer measures BMD, and the software then applies these reference data and algorithms to present results. However, it's not a standalone diagnostic AI algorithm in the contemporary sense.
7. The Type of Ground Truth Used
For the reference population, the "ground truth" is implicitly derived from statistical analysis of a defined "healthy young adult" population. This isn't pathology, outcomes data, or expert consensus on individual cases, but rather population-level normative data representing ideal bone mineral density for healthy young adults.
8. The Sample Size for the Training Set
The 510(k) summary does not specify the sample size for the "reference sets" (which serve as the basis for the device's capability, akin to a training set for normative data).
9. How the Ground Truth for the Training Set Was Established
The document states: "Two reference sets are provided, one for female Caucasians and one for male Caucasians. These reference data sets allow comparison of Apollo™ BMD scan results to healthy young adults aged 20 to 42."
The method for establishing these "reference sets" (the "ground truth" for normative data) is not detailed in this summary. Typically, such reference populations are established through:
- Careful selection of individuals meeting specific health criteria (e.g., no known conditions affecting bone metabolism, within a specific age range, ethnicity).
- Measurement of their bone mineral density using the densitometer.
- Statistical analysis of this data to derive mean BMD values and standard deviations for different age groups within the defined population.
The predicates mentioned (K931996 for pDEXA™ Reference Population and K973104 for Fracture Risk Assessment) imply that established methodologies for creating and using reference populations for bone densitometers were followed for the Apollo™ system.
§ 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.