The PIXI™ young adult reference population for os calcis and forearm provides the ability to compare the BMD result of the PIXI™ to the value of an average young adult, age 20-45 years old, of the same sex. The results from this comparison are expressed as a percentage of young adults, or as a T-score, defined as a number of standard deviations from the young adult value.

This additional feature is highly comparable to similar features in the Norland pDEXA as well as the Osteon Osteoanalyzer densitometers.

The use of the PIXI™ young adult reference population for os calcis and forearm, is restricted to prescription use only.

Device Description

The reference BMD values incorporated in this submission, provides the ability to compare the BMD result of the PIXI™, to the value of an average young adult, age 20 - 45 years old, of the same sex. The results from this comparison are expressed as a percentage of young adult, or as a T-Score, defined as number of standard deviations from the young adult value.

AI/ML Overview

The provided text describes a 510(k) submission (K972053) for the PIXI™ young adult reference population for os calcis and forearm, which is an enhancement to a bone densitometer. The submission focuses on establishing descriptive reference data rather than a device's diagnostic performance against a specific disease. Therefore, the traditional acceptance criteria and study design for diagnostic devices (e.g., sensitivity, specificity, reader studies with AI assistance) are not directly applicable in the same way.

Instead, the "acceptance criteria" here relate to the adequacy and representativeness of the reference population data for calculating T-scores and percentage comparisons. The "study" is the data collection process for this reference population.

Here's an attempt to structure the information based on your request, adapting where necessary given the nature of the submission:

Acceptance Criteria and Study for PIXI™ Young Adult Reference Population for Os Calcis and Forearm (K972053)

This 510(k) submission describes the integration of a new reference population into the PIXI™ bone densitometer. The primary "performance" being evaluated is the generation of statistically sound and representative normative data for young adults (20-45 years old) to allow for the calculation of T-scores (number of standard deviations from the young adult mean) and percentage comparisons. Since this is a reference dataset for a measurement device, traditional diagnostic performance metrics (e.g., sensitivity, specificity, AUC) are not presented.

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Implicit from Submission)	Reported Device Performance (as described for the reference population)
Adequacy of Sample Size: Sufficient number of individuals to establish reliable mean and standard deviation for BMD at specified sites and sex.	Os Calcis:- Female: n=143, Mean=0.556, SD=0.089- Male: n=107, Mean=0.682, SD=0.106Forearm:- Female: n=126, Mean=0.523, SD=0.062- Male: n=91, Mean=0.623, SD=0.085
Demographic Representativeness: Data collected from a "normal white young adult" population as appropriate for the intended use.	Data collected on "normal white young adult men and women, age 20 to 45 years." (Specific country of origin not stated but implied to be North America given the submitter's location).
Comparability to Predicate Devices: The method of using reference values is consistent with existing, legally marketed bone densitometers.	"The use of reference values with the PIXI™ bone densitometer is comparable to how reference values are utilized on other commercially available bone densitometers." The feature is also stated to be "highly comparable to similar features in the Norland pDEXA as well as the Osteon Osteoanalyzer densitometers" (identified as predicate devices). This indicates functional equivalence.
No New Safety and Effectiveness Questions: The addition of this reference population does not introduce new risks or concerns.	"No new safety and effectiveness questions are raised with PIXIM young adult reference population for os calcis and forearm."

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

In this context, the "test set" is the population from which the reference data was collected.

Sample Size:
- Os Calcis: 143 females and 107 males.
- Forearm: 126 females and 91 males.
Data Provenance:
- Country of Origin: Not explicitly stated but the company (LUNAR Corporation) is based in Madison, WI, USA, strongly implying US-based data collection.
- Retrospective or Prospective: Not explicitly stated. However, the phrasing "Data were collected on normal white young adult men and women" suggests a prospective collection of data for the purpose of establishing this reference.

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

This is not applicable in the traditional sense for this submission. The "ground truth" here is the measured BMD values themselves from the healthy young adult population. There is no diagnostic classification being made that would require expert consensus for ground truth. The expertise would lie in the design of the study, proper operation of the densitometer, and statistical analysis of the collected data. The submission does not detail who designed or executed the data collection.

4. Adjudication Method for the Test Set

Not applicable. There is no diagnostic uncertainty or disagreement requiring adjudication in the collection of these normative BMD values.

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

Not applicable. This submission is for a reference population used in a bone densitometer feature, not an AI-based diagnostic tool that assists human readers in interpreting images.

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done

This concept doesn't directly apply here. The "algorithm" in this case is the statistical calculation of T-scores and percentage comparisons using the collected reference data. The device's primary function (measuring BMD) is standalone, and the reference population provides comparative context to that measurement. There isn't an "algorithm only" performance separate from the reported means and standard deviations of the reference data.

7. The Type of Ground Truth Used

The "ground truth" is the measured Bone Mineral Density (BMD) values from a defined population of "normal white young adult men and women, age 20 to 45 years." It's not clinical outcomes, pathology, or expert consensus on a diagnostic finding. It represents a statistical description of a healthy population.

8. The Sample Size for the Training Set

In this context, the "training set" is essentially the same as the "test set" described for the reference population. The data collected constitutes the reference (training) data for future comparisons.
- Os Calcis: 143 females and 107 males.
- Forearm: 126 females and 91 males.

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

The ground truth (i.e., the BMD values themselves) for this reference population was established through direct measurement using a bone densitometer (presumably the PIXI™ device itself or a similar predicate device). The data was collected from "normal white young adult men and women, age 20 to 45 years," implying a recruitment process for healthy individuals within this demographic range. The submission does not detail the specific methodology for subject recruitment or measurement protocols beyond stating the demographic and the measured sites.

Summary

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K972053

313 W. BELTLINE HIGHWAY

MADISON, WI 53713

(608) 274-2663

AUG - 8 1997

510(k) SUMMARY OF SAFETY AND EFFECTIVENESS 10.0

This summary of safety and effectiveness information is submitted in accordance with the requirements of 21 CFR 807.92(c).

Contact Person:	Kenneth D. BurokerLUNAR Corporation313 West Beltline HighwayMadison, WI 53713
Phone:	(608) 288-6460
Fax:	(608) 274-0853
Date:	May 29, 1997
Device/Trade Name:	PIXITM young adult reference population for os calcis andforearm.
Common Name:	Bone Densitometer
Classification Name:	Bone Densitometer21CFR 892.1170
Predicate Device:	Osteon Osteoanalyzer510 (k) K891582Norland pDEXA510 (k) K931996

DESCRIPTION OF DEVICE 10.1

The reference BMD values incorporated in this submission, provides the ability to compare the BMD result of the PIXI™, to the value of an average young adult, age 20 - 45 years old, of the the BMD result of the FTAT - , to the vatus of an areased as a percentage of young adult, or as a T-Score, defined as number of standard deviations from the young adult value.

Data were collected on normal white young adult men and women, age 20 to 45 years. This data is summarized as shown in Table A.

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	Female			Male
Site	n	Mean	SD	n	Mean	SD
Os Calcis	143	0.556	0.089	107	0.682	0.106
Forearm	126	0.523	0.062	91	0.623	0.085

Table A

10.2 CONCLUSION

The use of reference values with the PIXI™ bone densitometer is comparable to how reference values are utilized on other commercially available bone densitometers. This feature can be used by the clinician entirely at his/her discretion. No new safety and effectiveness questions are raised with PIXIM young adult reference population for os calcis and forearm.

Signature

Kenneth D. Buroker Printed Name

Director, Regulatory Affairs Title

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Image /page/2/Picture/0 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized caduceus symbol, which features a staff with a snake winding around it, and three horizontal bars above it. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES" is arranged in a circular fashion around the symbol.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

AUG - 8 1997

Kenneth D. Buroker Director, Regulatory Affairs Lunar Corporation 313 W. Beltline Highway Madison, WI 53713

Re: K972053

PIXI™ Young Adult Reference Population for OS Calcis and Forearm Dated: May 29, 1997 Received: June 2, 1997. Regulatory Class: II 21 CFR 892.1170/Procode: 90 KGI

Dear Mr. Buroker:

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.

If your device is classified (see above) into either class III (Premarket Aproval), 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 yitro 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 (30) 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/cdrh/dsmamain.html"

Sincerely your

Lillian Yin, Ph.D.

Lilian 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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INDICATION FOR USE FORM 4.0

Page 1 of 1

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501(k) Number (if known) K972053
PIXI™ young adult reference population for os calcis . Device name: and forearm... .. . . . .
Indications For Use: .

This additional feature is highly comparable to similar features in the Norland pDEXA as well as the Osteon Osteoanalyzer densitometers.

The use of the PIXI™ young adult reference population for os calcis and forearm, is restricted to prescription use only. The operator's manual for the PIXI system contains the following statement:

"United States Federal Law restricts this device to the sale, distribution, and use by or on the order of a physician."

PLEASE DO NOT WRITE BELOW THIS LINE. CONTINUE ON ANOTHER PAGE IF NEEDED.

Concurrence of CDRH, Office of Device Evaluation (ODE)
(Division Sign-Off)
Division of Reproductive, Abdominal, ENT,and Radiological Devices
510(k) Number	K972053
Prescription Use	X
(Per 21 CRF 801.109)
	OR
Over-the-Counter Use	__________
(Optional Format 1-2-96)

Regulation Number and Section

§ 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.