(154 days)
The Norland Body Composition Option (body composition) assesses the non-bone tissue determined during the bone density scans performed by Norland DEXA bone densitometers, and estimates soft tissue mass, fat mass, lean mass, total soft tissue mass, % fat, TBMC/LBM (Total Bone Mineral Content / Lean Body Mass), and Siri and Brozek equation equivalent values.
These body composition estimates are useful to health care professionals in their management of diseases/conditions where the disease/condition itself, or its treatment, can affect the relative amounts of patient fat and lean tissue. The Norland Body Composition Option does not diagnose disease, or recommend treatment regimens, or quantify treatment effectiveness. Only the health care professional can make these judgments. Some of the diseases/conditions for which lean and fat tissue estimates are useful are chronic renal failure, Anorexia Nervosa, excessive obesity, AIDS/HIV, and Cystic Fibrosis. Body composition is also a convenient alternative to hydrostatic weighing and skin fold measurements.
The Norland Body Composition Option (body composition) is used with Norland DEXA bone densitometers to estimate the relative amounts of lean and fat tissue in the scan area. Body composition does not require any changes to the bone densitometer nor does it require additional scanning or radiation exposure beyond the bone density scans. In most cases, existing scans can be re-analyzed to provide the body composition values. Although body composition is most useful for whole body scans, it is compatible with all scan modes for Norland DEXA bone densitometers. Body composition values for whole body scans were compared to underwater weighing (UWW) values in clinical studies involving hundreds of subjects. The UWW values were determined using both the Siri and Brozek equations. Based on this study, the Norland body composition provides the Siri and Brozek equivalent values for the Whole Body scans.
The provided text describes the Norland Body Composition Option, a software addition to DEXA bone densitometers. The information available focuses on the device's intended use, safety, and regulatory clearance via 510(k) summary, rather than a detailed scientific study with explicit acceptance criteria.
However, based on the text, we can infer some details about the study and acceptance criteria related to its substantial equivalence claim.
1. Table of Acceptance Criteria and Reported Device Performance
The document states: "Body composition values for whole body scans were compared to underwater weighing (UWW) values in clinical studies involving hundreds of subjects. The UWW values were determined using both the Siri and Brozek equations. Based on this study, the Norland body composition provides the Siri and Brozek equivalent values for the Whole Body scans."
While specific numerical acceptance criteria (e.g., a specific correlation coefficient or percentage agreement) are not provided, the implicit acceptance criterion is that the Norland Body Composition Option's values "provide the Siri and Brozek equivalent values." This suggests that the device's output was considered sufficiently close to the UWW measurements (calculated via Siri and Brozek equations) to be deemed equivalent and acceptable.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Device provides "Siri and Brozek equivalent values" for Whole Body scans compared to Underwater Weighing (UWW) measurements. | The Norland body composition provides the Siri and Brozek equivalent values for the Whole Body scans. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: "clinical studies involving hundreds of subjects."
- Data Provenance: The document does not specify the country of origin. It does not explicitly state whether the data was retrospective or prospective, but "clinical studies" typically imply prospective data collection for such comparisons.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This information is not provided in the document. Underwater weighing (UWW) is a direct measurement method for body density, from which body composition is calculated using established equations (Siri and Brozek). Therefore, human expert "ground truthing" in the sense of image interpretation is not directly applicable to the UWW measurements themselves. The expertise would lie in correctly performing UWW and applying the equations, which is assumed.
4. Adjudication Method for the Test Set
Not applicable, as the ground truth (UWW) is a direct measurement, not an expert-driven assessment requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC study was not done. The study described compares the device's output to a physical measurement (UWW), not to human readers' interpretations with and without AI assistance.
6. If a Standalone Study (i.e., algorithm only without human-in-the-loop performance) was done
Yes, the study described is a standalone performance assessment. The Norland Body Composition Option, a software feature, generates body composition values, which were then directly compared to UWW values. There's no mention of a human-in-the-loop component in this comparison.
7. The Type of Ground Truth Used
The ground truth used was outcomes data / physical measurement, specifically Underwater Weighing (UWW), from which body composition values were derived using the Siri and Brozek equations. This is considered a gold standard for body composition assessment.
8. The Sample Size for the Training Set
The document does not specify a separate training set or its sample size. The description of the clinical study appears to refer to the validation of the device's output against UWW. Given the nature of this 510(k) summary for a software option, it's possible the core algorithms for converting DEXA data to body composition were developed and validated independently prior to this specific submission, or the "clinical studies involving hundreds of subjects" served as the primary validation set for the software's performance against a gold standard.
9. How the Ground Truth for the Training Set was Established
This information is not provided, as a distinct training set and its ground truth establishment are not discussed in the document. If the "clinical studies involving hundreds of subjects" served as the primary validation, then the ground truth for this validation was established via Underwater Weighing (UWW) as described in point 7.
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FEB 1 3 1998
K973459
510k Summary
as required by 807.92(c) for Norland Body Composition Option
Prepared January 1998
Norland Corporation Submitted by: W6340 Hackbarth Road Fort Atkinson. WI 53538 Reg. # 2124648 920-563-8456 Mr. Terry Schwalenberg Contact Person: Director Regulatory Affairs Norland Body Composition Option Device Trade Name: Body Composition Option for DEXA bone densitometers Common Name: Classification: Bone densitometer, (21 CFR 892.1170), product code 90KGI; Class II Predicate Devices: Lunar Total Body Software Option for the DPX bone densitometer (K935454) The Norland Body Composition Option (body composition) is used with Description of Norland DEXA bone densitometers to estimate the relative amounts of lean Device: and fat tissue in the scan area. Body composition does not require any changes to the bone densitometer nor does it require additional scanning or radiation exposure beyond the bone density scans. In most cases, existing scans can be re-analyzed to provide the body composition values. Although body composition is most useful for whole body scans, it is compatible with all scan modes for Norland DEXA bone densitometers. Body composition values for whole body scans were compared to underwater weighing (UWW) values in clinical studies involving hundreds of subjects. The UWW values were determined using both the Siri and Brozek equations. Based on this study, the Norland body composition provides the Siri and Brozek equivalent values for the Whole Body scans. Intended use Body composition assesses the non-bone tissue determined during the bone density scans performed by Norland DEXA bone densitometers, and estimates soft tissue mass, fat mass, lean mass, total soft tissue mass, % fat, TBMC/LBM (Total Bone Mineral Content / Lean Body Mass), and Siri and Brozek equation equivalent values.
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These body composition estimates are useful to health care professionals in their management of diseases/conditions where the disease/condition itself, or its treatment, can affect the relative amounts of patient fat and lean tissue. The Norland Body Composition Option does not diagnose disease, or recommend treatment regimens, or quantify treatment effectiveness. Only the health care professional can make these judgments. Some of the diseases/conditions for which lean and fat tissue estimates are useful are chronic renal failure, Anorexia Nervosa, excessive obesity, AIDS/HIV, and Cystic Fibrosis. Body composition is also a convenient alternative to hydrostatic weighing and skin fold measurements.
Safety
Body composition doesn't require additional radiation exposure over what is required for the bone density scan alone. The data which is normally analyzed for the bone values can also be analyzed for the lean and fat values. During the scan, the subject lies quietly on a cushioned table (or sits in a chair); they are not required to be in contact with any electrical part or to ingest any chemical/drug.
The delivered dose for Norland bone densitometers range from 0.07 mrem for a whole body scan, to 3 mrem for a pDEXA forearm scan, to 10 mrem for a hip scan. Stray radiation is very small. At a distance of three feet from the x-ray beam, the radiation field is less than 0.1 mRem per hour. This field is present only during the few minutes of the actual patient scan; and is primarily scatter from the patient. Shielded rooms are not required, and the operators are not required to be out of the room during the scan. These dose levels compare favorably to the background radiation level of 100 mrem per year; to a chest x-ray of 35 mrem; and to the increased dose received during a cross country (round trip) airline flight of 5 mrem.
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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 a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is an abstract image of an eagle.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
FEB 1 3 1998
Terry Schwalenberg Director, Regulatory Affairs Norland Corporation W6340 Hackbarth Rd. Fort Atkinson, WI 53538-8999 Re: K973459
Norland Body Composition Option for Norland Dexa Bone Densitometers Dated: January 5, 1998 Received: January 6, 1998 Regulatory class: II 21 CFR 892.1170/Procode: 90 KGI
Dear Mr. Schwalenberg:
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 Device Amendments, or to 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.
If your device is classified (see above) into either class III (Premarket 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 Current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS 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 submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under 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 vitte diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for question 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 http://www.fda.gov/cdrbdsmamain.html": ---------------------------------------------------------------------------------------------
Sincerely yours,
h. Tiau Yu.
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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Indications for Use
510(k) number (if known):
Device Name: Body Composition Option for Norland DEXA Bone Densitometers
Indications for use:
The Norland Body Composition Option (body composition) assesses the non-bone tissue determined during the bone density scans performed by Norland DEXA bone densitometers, and estimates soft tissue mass, fat mass, total soft tissue mass, % fat, TBMC/LBM (Total Bone Mineral Content / Lean Body Mass), and Siri and Brozek equation equivalent values.
These body composition estimates are useful to health care professionals in their management of diseases/conditions where the disease/condition itself, or its treatment, can affect the relative amounts of patient fat and lean tissue. The Norland Body Composition Option does not diagnose disease, or recommend treatment regimens, or quantify treatment effectiveness. Only the health care professional can make these judgments. Some of the diseases/conditions for which lean and fat tissue estimates are useful are chronic renal failure, Anorexia Nervosa, excessive obesity, AIDS/HIV, and Cystic Fibrosis. Body composition is also a convenient alternative to hydrostatic weighing and skin fold measurements.
- (Please do not write below this line - continue on another page if needed) -----------Concurrence of CDRH; Office of Bevice Evaluation (ODE)--------------
Prescription Use (Per 21 CFR 801.109)
(Optional Format 1-2-96)
OR
Over-the-counter Use
David le. Sejimm
(Division Sign-Off)
Division of Reproductive, Abdominal, ENT and Radiological Devices
510(k) Number K973459
§ 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.