The intended use of the CTXA Hip Extence Data accessory for the CTXA Hip Bone Mineral Densitometry module is to provide a context for the clinical interpretation of a patient's proximal femur BMD estimates. T-scores are calculated relative to a US normal female Caucasian reference population age 20-39 years, and Z-scores are calculated relative to a US normal female Caucasian reference population age 20-79 years. The use of a reference data set and the interpretation of parameters derived by the CTXA Hip module when comparing patient-specific BMD estimates to the installed and selected reference data set is at the discretion of the physician.

Device Description

The CTXA Hip Extenced Reference Data is an accessory to the CTXA Hip Bone Mineral Densitometer. The CTXA Hip Extended Reference Data is used within the CTXA Hip module to calculate T-scores and percent young normal for any patient, and Z-scores for patients age 20-80 for BMD estimates made using the CTXA Hip module.

AI/ML Overview

The provided text describes a 510(k) premarket notification for the "CTXA Hip Extended Reference Data" device, which is an accessory to the CTXA Hip Bone Mineral Densitometer. The purpose of this accessory is to provide a broader reference dataset for calculating T-scores and Z-scores for Bone Mineral Density (BMD) estimates from the CTXA Hip module.

1. A table of acceptance criteria and the reported device performance:

Acceptance Criteria (Implicit)	Reported Device Performance
Premarket Equivalence to Predicate Device: The device must demonstrate substantial equivalence to the legally marketed predicate device (K002113: CTXA Hip Bone Mineral Densitometer) in terms of safety and effectiveness, despite the expanded reference data.	The CTXA Hip Extended Reference Data is intended to be an accessory to the CTXA Hip Bone Mineral Densitometer. The submission explicitly states: "The CTXA Hip Extended Reference Data is substantially equivalent to the listed predicate device."
Accuracy of BMD Estimates: BMD estimates obtained with the accessory should be consistent with those from the predicate device.	"BMD estimates obtained with CTXA Hip with Extended Reference Data accessory are identical to BMD estimates obtained with the predicate CTXA Hip."
Clinical Significance of T-score Differences: Any differences in calculated T-scores due to the expanded reference data should not be clinically significant.	"T-scores calculated with CTXA Hip with Extended Reference Data accessory are slightly less negative than those calculated with CTXA Hip, approximately 0.1-0.2 Tscore units. This difference is not significant clinically."
Clinical Interpretation: The clinical interpretation of BMD estimates made with the accessory should be comparable to that of the predicate device.	"The clinical interpretation of BMD estimates made with CTXA Hip Extence Data is comparable to that associated with the predicate device."
Expanded Z-score Range: The device must successfully calculate Z-scores for a broader age range (20-80 years) compared to the predicate (20-39 years).	The device description and intended use clearly indicate this expanded capability: "The current CTXA Hip Extence Data is an accessory to CTXA Hip that also is used to calculate T-scores and percent young normal, and also is used to calculate Z-scores for ages 20-80." And in Indications for Use: "Z-scores are calculated relative to a US normal female Caucasian reference population age 20-79 years."

2. Sample size used for the test set and the data provenance:

The document does not explicitly state a specific sample size used for a test set in the context of a validation study for the "CTXA Hip Extended Reference Data" accessory itself.

Instead, the substantiation for substantial equivalence appears to rely on:

Logical deduction: BMD estimates are "identical" to the predicate, implying the core measurement accuracy is unchanged.
Quantification of T-score differences: A "0.1-0.2 T-score unit" difference, which is then deemed "not significant clinically."
Reference Population: The reference data set used for T-scores and Z-scores is described as a "US normal female Caucasian reference population." The specific size, collection methodology (retrospective/prospective), or exact provenance (e.g., specific study) of this reference population is not detailed in the provided text.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

The document does not mention the use of experts to establish ground truth for a test set in the context of the device's performance evaluation. The device's function is a calculation based on predefined reference data, not a diagnostic interpretation that typically requires expert consensus for ground truth.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

Not applicable. The document does not describe an adjudication method for a test set, as its evaluation focuses on the consistency of calculations and the clinical insignificance of minor differences, rather than a diagnostic accuracy study where adjudication is common.

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. The device, "CTXA Hip Extended Reference Data," is an accessory for a bone densitometer providing reference data for score calculation. It does not involve AI assistance to human readers or a multi-reader multi-case study. It simply provides a new reference population for existing BMD measurements.

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

The device's core function is standalone in the sense that it provides a calculation of T-scores and Z-scores based on a reference database. The "algorithm" (i.e., the method of calculating these scores against the reference data) is performed without human intervention in the calculation itself. However, the interpretation of these scores "is at the discretion of the physician," meaning the overall diagnostic process remains human-in-the-loop. The document focuses on the accuracy and clinical insignificance of differences in these calculated scores.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

The "ground truth" in this context refers to the reference population data against which patient BMD estimates are compared to calculate T and Z scores. The document describes this as a "US normal female Caucasian reference population age 20-39 years" for T-scores and "US normal female Caucasian reference population age 20-79 years" for Z-scores. The specific methodology for establishing this "normal" reference population (e.g., how subjects were selected, what criteria defined "normal," how BMD was measured for this database) is not detailed in the provided text.

8. The sample size for the training set:

The document does not mention a training set in the context of machine learning or AI. The "reference data" would be analogous to a training set here, but its sample size is not specified.

9. How the ground truth for the training set was established:

The document does not detail how the "US normal female Caucasian reference population" (which serves as the "ground truth" or reference for the device's calculations) was established. It is simply referred to as a "reference population."

Summary

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KO3O33O

510(k) SUMMARY OF SAFETY AND EFFECTIVENESS

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

Contact Information:	Christopher E. Cann, Ph.D.CEO and Director of Research and DevelopmentMindways Software, Inc282 Second St., 4th FloorSan Francisco, CA 94105Phone: 415-247-9932Fax: 415-247-9931Email: chris@gct.com
Date:	January 30, 2003
Device/Trade Name:	CTXA Hip Extended Reference Data
Common/Usual Name:	Bone Mineral Densitometer
Classification Name:	Bone Densitometer, 21 CFR 892.1170, Class II
	Predicate Devices:

K002113: CTXA Hip Bone Mineral Densitometer

Device Description

Intended Use

The intended use of the CTXA Hip Extence Data accessory for the CTXA Hip Bone Mineral Densitometry module is to provide a context for the clinical interpretation of a patient's proximal femur BMD estimates. The use of a reference data set and the interpretation of parameters derived by the CTXA Hip module when comparing patient-specific BMD estimates to the installed and selected reference data set is at the discretion of the physician.

Summary of Technological Characteristics and Comparison with Predicate Devices

The predicate K002113 CTXA Hip Bone Mineral Densitometer Module (CTXA Hip) provides estimates of bone mineral content (BMC) and bone mineral density (BMD) values similar to those obtained from DXA devices. These BMD estimates from the predicate device are compared to a reference database of age 20-39 US Caucasian females to calculate T-scores and percent young normal for patient BMD estimates and Z-scores for patient BMD estimates for ages 20-39. The current CTXA Hip Extence Data is an accessory to CTXA Hip that also is used to calculate T-scores and percent young normal, and also is used to calculate Z-scores for ages 20-80. The CTXA Hip BMD estimates referenced to the CTXA Hip Extence Data reference population are used as an aid to the physician in identifying patients with low bone mineral density and as an aid in determining a patient's fracture risk.

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Summary of Clinical Performance Data

BMD estimates obtained with CTXA Hip with Extended Reference Data accessory are identical to BMD estimates obtained with the predicate CTXA Hip. T-scores calculated with CTXA Hip with Extended Reference Data accessory are slightly less negative than those calculated with CTXA Hip, approximately 0.1-0.2 Tscore units. This difference is not significant clinically.

Conclusions

The CTXA Hip Extended Reference Data is substantially equivalent to the listed predicate device. The clinical interpretation of BMD estimates made with CTXA Hip Extence Data is comparable to that associated with the predicate device.

Cth Rm

Signature

Christopher Cann Printed Name

CEO and Director of Research and Development Title

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Image /page/2/Picture/1 description: The image shows the seal of the Department of Health & Human Services (HHS) of the USA. The seal is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is an abstract image of an eagle with three lines representing its wings.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Christopher E. Cann, Ph.D. CEO and Director of Research Mindways Software, Inc. 282 Second Street, Fourth Floor SAN FRANCISO CA 94105

Re: K030330

JUN 2 0 2003

Trade/Device Name: CTXA Hip Extended Reference Data Regulation Number: 21 CFR 892.1170 Regulation Name: Bone densitometer Regulatory Class: II Product Code: 90 KGI Dated: May 16, 2003 Received: May 19, 2003

Dear Dr. Cann:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). 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 II (Special Controls) or class III (PMA). it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (sections 531-542 of the Act); 21 CFR 1000-1050.

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This letter will allow you to begin marketing your device as described in your Section 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), please contact the Office of Compliance at one of the following numbers, based on the regulation number at the top of the letter:

8xx.1xxx	(301) 594-4591
876.2xxx, 3xxx, 4xxx, 5xxx	(301) 594-4616
884.2xxx, 3xxx, 4xxx, 5xxx, 6xxx	(301) 594-4616
892.2xxx, 3xxx, 4xxx, 5xxx	(301) 594-4654
Other	(301) 594-4692

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" (21CFR Part 807.97) you may obtain. Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.

Sincerely yours.

Nancy C. Brogdon

Nancy C. Brogdon Director, Division of Reproductive, Abdominal and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

Page 2

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Page

K030330

510(k) NUMBER (IF FINNI.)

CTXA HIP EXTENDED REFERENCE DATA DEVICE NAME :

INDICATIONS FOR USE:

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use (Per 21 CFR 801.109)

Over-The-Counter-Use (Optional Format 1-2-96)

David h. Lyman

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.