(400 days)
The intended use of the Hologic® Body Composition Software Option for QDR® X-Ray Bone Densitometers is to estimate the lean body mass and fat mass of non-osseous tissues in situations where medically necessary.
The Hologic® Body Composition Software Option for QDR® X-Ray Bone Densitometers is a software algorithm that permits an operator to display soft tissue characteristics. Soft tissue estimates are obtained using the Dual X-Ray Photon Absorptiometry (DXA) technique in which the x-ray tube emits alternating pulses of "high" and "low" energy x-rays which pass through the subject and are received by the detector array. The attenuation of the x-ray beam due to the subject is estimated by the detectors. By comparing the attenuation of the high and low energy pulses, the contributions of bone in the subject can be eliminated, leaving only the contributions due to non-osseous tissues.
Here's a breakdown of the acceptance criteria and study information for the Hologic® Body Composition Software Option for QDR® X-Ray Bone Densitometers, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly list quantitative "acceptance criteria" in the formal sense (e.g., minimum sensitivity, specificity, or specific error margins). Instead, it describes "performance data" that establishes the utility and validity and concludes substantial equivalence based on strong correlations and small differences compared to predicate devices and among its own models.
| Metric (Implicit Acceptance Criteria) | Reported Device Performance |
|---|---|
| Correlation with other modalities and within models for: | |
| Fat Mass | Correlation coefficient approximately 0.99 with strong positivity. Incremental percentage difference among models: ~2.5% |
| Lean Mass | Correlation coefficient approximately 0.99 with strong positivity. Incremental percentage difference among models: - |
| Total Soft Tissue Mass | Correlation coefficient approximately 0.99 with strong positivity. Incremental percentage difference among models: - |
| Percentage Fat | Correlation coefficient approximately 0.99 with strong positivity. Incremental percentage difference among models: ~0.5% |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify a distinct "test set" sample size. The performance data refers to:
- "Published reports using in vitro and in vivo models": No specific sample sizes for these are given.
- "Normative data generated among healthy individuals spanning the adult age-range (as well as in children and adolescents)": No specific sample size is given.
- "Studies included comparative experiments to evaluate DXA and other modalities": No specific sample size is given.
- "A study was also conducted to determine the strength of agreement among the QDR® models with the body composition software": No specific sample size is given.
Data Provenance: The document does not specify the country of origin of the data. The studies appear to be retrospective or a combination of retrospective analyses of published data and prospective internal studies ("A study was also conducted...").
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish ground truth for a test set in the traditional sense of human readers for image interpretation. The ground truth appears to be established through:
- Comparative experiments with "other modalities commonly used for estimating body composition": These other modalities would serve as the reference standard (ground truth). The nature and expertise involved in validating these other modalities are not detailed.
- Agreement among QDR® models: This suggests a self-validation approach within the Hologic ecosystem, implying the existing QDR® technology acted as a form of ground truth or reference.
4. Adjudication Method for the Test Set
No adjudication method is mentioned or implied, as the ground truth was established through comparison to other measurement modalities or internal consistency among QDR® models rather than human expert interpretation requiring adjudication.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No such MRMC comparative effectiveness study was mentioned. The device is a software algorithm for body composition measurement, not one requiring human interpretation of images in the context of an AI-assisted diagnostic workflow.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the performance data presented is for the standalone software algorithm. It performs the calculations for fat mass, lean mass, and total soft tissue mass based on the DXA data. The "operator" role is to display the characteristics, not to interpret raw data to derive the metrics themselves.
7. The Type of Ground Truth Used
The ground truth or reference standard appears to be:
- Comparative measurements from "other modalities commonly used for estimating body composition." The specific nature of these modalities (e.g., DEXA from other manufacturers, hydrostatic weighing, MRI) is not detailed.
- Internal consistency and agreement among different QDR® models themselves. This suggests that the established accuracy of existing QDR® hardware and software served as a reference.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" or its size. The device is a software algorithm for processing DXA data. Its development likely relied on historical data and established physiological models, rather than a distinct machine learning training set as understood today. The "published reports using in vitro and in vivo models" and "normative data" likely informed the algorithm's development and parameters.
9. How the Ground Truth for the Training Set Was Established
As no specific training set is outlined, the establishment of ground truth for training is not detailed. However, the foundational "utility and validity" of determining soft tissue components with QDR® devices was established through:
- In vitro and in vivo models.
- Comparative experiments evaluating DXA against other body composition modalities.
- Normative data from healthy individuals.
- Data from patients with syndromes affecting body composition (e.g., AIDS, cystic fibrosis).
This suggests that the algorithm's underlying principles were developed and validated against established scientific and medical understanding of body composition measurement, anchored by comparisons to other accepted methods and observations in various populations.
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510(k) SUMMARY
JUN 1 3 1997
గ్ర
Hologic® Body Composition Software Option for QDR® X-Ray Bone Densitometers
| Submitter Name: | Hologic, Incorporated |
|---|---|
| Submitter Address: | 590 Lincoln StreetWaltham, Massachusetts 02154 |
| Contact Person: | Nandini Murthy, Regulatory Scientist |
| Phone Number: | (617) 890-2300 |
| Fax Number: | (617) 890-8031 |
| Date Prepared: | May 8, 1996 |
| Device Trade Name: | Hologic® Body Composition Software Optionfor QDR® X-Ray Bone Densitometers |
| Device Common Name: | X-Ray Bone Densitometer |
| ProposedClassification Name: | Body Composition Software Optionfor Bone Densitometer |
| Predicate Devices: | DPX Tissue Quantitation Output; Lunar CorporationCT 9800; General Electric Corporation |
| Device Description: | The Hologic® Body Composition Software Option forQDR® X-Ray Bone Densitometers is a software algorithmthat permits an operator to display soft tissue characteristics.Soft tissue estimates are obtained using the Dual X-RayPhoton Absorptiometry (DXA) technique in which the x-raytube emits alternating pulses of "high" and "low" energy x-rays which pass through the subject and are received by thedetector array. The attenuation of the x-ray beam due to thesubject is estimated by the detectors. By comparing theattenuation of the high and low energy pulses, thecontributions of bone in the subject can be eliminated,leaving only the contributions due to non-osseous tissues. |
| Intended Use: | The intended use of the Hologic® Body Composition SoftwareOption for QDR® X-Ray Bone Densitometers is to estimate thelean body mass and fat mass of non-osseous tissues in situationswhere medically necessary. |
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Device Technological There is no significant change from existing QDR® software for total body scans. However, as an optional Characteristics and feature, operators are now able to display soft-tissue Comparison to characteristics, specifically estimation of lean body mass and Predicate Devices: fat mass of non-osseous tissues in situations where medically necessary. Published reports using in vitro and in vivo models have Performance Data: established the utility and validity of determining the soft tissue components of body composition with the QDR® devices. Studies included comparative experiments to evaluate DXA and other modalities commonly used for estimating body composition; normative data generated among healthy individuals spanning the adult age-range (as well as in children and adolescents); and the value of DXA among patients with syndromes known to affect body composition (e.g., AIDS and cystic fibrosis). A study was also conducted to determine the strength of agreement among the ODR® models with the body composition software. Measurements were recorded for fat mass, lean mass, total soft tissue mass and percentage fat for each subject. All correlation coefficients were strongly positive; approximately 0.99 for each comparison. The incremental percentage difference among the models was small, ranging from approximately 0.5% for percentage fat to 2.5% for fat mass. These data support the conclusion that, in selected cases, such as monitoring of patients where marked changes in body composition are expected, the ODR® models may be used interchangeably, especially if attention is given to obtaining cross-calibration data. Conclusion: The Hologic® Body Composition Software Option for ODR® X-Ray Bone Densitometers is substantially equivalent to predicate devices for the intended use of estimation of lean body mass and fat mass of non-osseous tissues in situations where medically necessary.
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Image /page/2/Picture/0 description: The image shows the logo for the Department of Health & Human Services USA. The logo is circular, with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" arranged around the perimeter of the circle. In the center of the circle is a stylized image of three human figures.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
Nandini Murthy Regulatory Scientist Hologic, Inc. 590 Lincoln Street Waltham, Massachusetts .02154 ..................
JUN 1 3 1997
Dear Ms. Murthy: 参
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
Re: K961787
Dated: May 1, 1997
Received: May 5, 1997 Regulatory class: II
Hologic Body Composition Software Option for
QDR® X-Ray Bone Densitometers
21 CFR 892.1170/Procode: 90 KGI
If your device is classified (see above) into either class III (Prematce Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Good Manufacturing Practice for Medical Devices: General (GMP) regulation (21 CFR Part 820) and that, through periodic GMP inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification does not affect any obligation you might have under sections 51 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in yitro diagnostic devices), please contact the Office of Compliance at (301) 594-4591 for Radiology devices, or 594-4613 for Ear, Nose and Throat devices. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address . پ "http://www.fda.gov/cdrh/dsmamain.html".
Sincerely yours,
Lillian Xia, Ph.D.
Lillian Yin, Ph.D. Director, Division of Reproductive, Abdominal, Ear, Nose and Throat, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Number (if known):
Device Name:
Hologic® Body Composition Software Option for QDR® X-Ray-Bone- -----Densitometers
Indications For Use: ત્ત્વ
The intended use of the Hologic® Body Composition Software for QDR® X-Ray Bone Densitometers is to estimate the lean body mass and fat mass of non-osseous tissues in situations where medically necessary.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEFDED)
Concurrence of CDRH; Office of Device Evaluation (ODE)
| Prescription Use(Per 21 CFR 801.109) | X |
|---|---|
| ------------------------------------------ | --- |
OR... Over-The-Counter Use
(Optional Format 1-2-96)
(Division Sign-Off)
Division of Reproductive, Abdominal, ENT, and Radiological Devices
| 510(k) Number | K961787 |
|---|---|
| --------------- | --------- |
§ 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.