K Number
K072664
Date Cleared
2008-11-21

(428 days)

Product Code
Regulation Number
892.1170
Panel
RA
Reference & Predicate Devices
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The GE Lunar Femur Strength analysis software option is an accessory to currently marketed GE Lunar DEXA bone densitometer devices, which are intended to estimate the bone mineral density and body composition (lean and fat tissue mass) of patients when medically indicated by their physicians. The Femur Strength software is intended to measure the hip axis length (HAL) and provides female adult Caucasian and Asian mean reference values of HAL from previously acquired GE Lunar femur scans.

The software calculates hip geometry values used to evaluate the structural properties of the hip, such as sub-region lengths, angles, ratios, buckling ratio, section modulus (Z), cortical thickness, cross-sectional area (CSA) and cross-sectional moment of inertia (CSMI). The software calculates a Femur Strength Index (FSI), a strength/stress ratio incorporating geometric properties of the hip such as CSMI, CSA, bone mineral density (BMD), patient age, height and weight. A ScanCheck feature is included to provide online messages to assist the operator or physician in checking that the scan was correctly taken. Color mapping of the variable density of bone images is also provided.

The values measured or computed provide additional information about the structure of the hip. They should be used in conjunction with the BMD T-score and other clinical risk factors as an aid in the diagnosis of osteoporosis and medical conditions leading to reduced bone density, and ultimately in the assessment of fracture risk.

Device Description

The Femur Strength Software Option for GE Lunar DEXA Bone Densitometers analyzes femur BMD scans to measure hip axis length (HAL) and provides a mean reference value of HAL and HAL fracture risk indication. The software calculates hip geometry values used to estimate the structural properties of the hip such as buckling ratio, section modulus (Z), cross-sectional area (CSA) and cross-sectional moment of inertia (CSMI). The software calculates a Femur Strength Index (FSI) based on inputs of CSMI, CSA, bone mineral density (BMD), patient age, height and weight. FSI represents the biomechanical properties of the hip and provides an estimate of the risk of fracture resulting from a fall on the hip.

AI/ML Overview

Here's an analysis of the acceptance criteria and study information for the GE Lunar Femur Strength Software based on the provided document:

This 510(k) submission states that no clinical tests were required to establish the safety or effectiveness of the device. Instead, the submission relies on the device's substantial equivalence to previously cleared predicate devices and non-clinical tests. Therefore, it's not possible to provide a table of acceptance criteria and reported device performance directly from a clinical study for this specific device.

However, the document does describe non-clinical tests that were performed, which can be interpreted as meeting certain "design specifications" that serve as a form of acceptance criteria.


Summary of Acceptance Criteria and Study Information:

Since no clinical study was performed for this device, a direct comparison of acceptance criteria to reported device performance from a clinical study cannot be provided. Instead, the non-clinical tests serve as the primary evidence.

1. Table of Acceptance Criteria and Reported Device Performance:

Acceptance Criteria CategorySpecific CriteriaReported Device PerformanceStudy that Proves Device Meets Criteria
Non-Clinical PerformanceIn vitro precision and accuracy values"within design specifications"Series of tests on phantoms
SafetyElectrical and mechanical safety conformity"conforms with applicable medical device safety standards"Evaluation against standards (not detailed in this document)
Quality SystemsConformity to quality system regulations"conforms with 21 CFR 820 and ISO 13485 quality systems"Manufacturer's internal processes, independent evaluation with ongoing factory surveillance
Substantial EquivalenceComparable to predicate devices in technological characteristics, safety, effectiveness, design, construction, materials, and intended uses"substantially equivalent to currently marketed devices"Comparison to Hologic Hip Structural Software Option and GE Lunar Prodigy Advanced hip assessment Software option

2. Sample Size for the Test Set and Data Provenance:

  • Sample Size: Not applicable for a clinical test set, as no clinical tests were performed. For the in vitro phantom tests, the sample size is not specified but is a "series of tests on phantoms."
  • Data Provenance: Not applicable for clinical data. For the in vitro phantom tests, the provenance is internal lab testing with phantoms.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:

  • Not applicable as no clinical ground truth was established by experts for a clinical test set. The "ground truth" for the phantom tests would be the known properties of the phantoms.

4. Adjudication Method:

  • Not applicable as no human-based ground truth adjudication was performed.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

  • No MRMC comparative effectiveness study was done. The document explicitly states, "No clinical tests were required to establish safety or effectiveness."

6. Standalone Performance:

  • The document describes the software's capabilities to calculate various parameters (HAL, FSI, etc.) based on BMD scans. The in vitro precision and accuracy tests on phantoms assessed the device's standalone performance in measuring these parameters, indicating they were "within design specifications."

7. Type of Ground Truth Used:

  • For the non-clinical tests, the ground truth was the known properties of the phantoms used to test in vitro precision and accuracy.
  • For the substantial equivalence claim, the ground truth is the performance and characteristics of the legally marketed predicate devices.

8. Sample Size for the Training Set:

  • Not applicable/Not provided. The document does not discuss a "training set" in the context of machine learning. The software's algorithms are likely based on established biomechanical models and equations, not solely on a data-driven training set in the modern AI sense.

9. How the Ground Truth for the Training Set Was Established:

  • Not applicable/Not provided. Given the nature of the device (calculating biomechanical properties based on established principles and BMD scans), ground truth for a "training set" (if one existed in a classical sense) would likely be based on expert knowledge, physical models, or previously validated population data used to derive the equations and reference ranges. The document does not detail this.

In summary: This 510(k) submission relied on non-clinical testing and substantial equivalence to predicate devices rather than clinical studies with human participants to establish safety and effectiveness. Therefore, many of the typical clinical study criteria fields are not applicable in this case.

§ 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.