The accuDEXA is a dual-energy x-ray device indicated for use in measuring an index of the bone density of the middle finger of the nondominant hand (BMD). This BMD value is a relative indicator of bone density elsewhere in the body. The measurement is compared to similar measurements from patients of the same gender and ethnicity to provide t-scores (number of standard deviations above or below the mean for a reference group of young healthy individuals) and z-scores (number of standard deviations above or below the mean for a cohort of the same age). A t-score or a z-score may be used by a physician as one factor, in conjunction with other clinical indicators, to diagnose osteoporosis and other bone disorders. When a normative database of the same ethnicity and gender is not available, the BMD value may still be used to compare to the patient's own baseline value, for example in following the patient's response to treatment for osteoporosis.

Below normal bone density can be associated with a variety of conditions or disorders of bone. For example, the Society of Nuclear Medicine and American College of Nuclear Physicians has identified specific medical indications for measurement of a patient's bone mass: for patients with premenopausal oophorectomy, spontaneous menopause, or estrogen deficiency conditions; for treatment-related osteopenia; when the diagnosis of osteopenia is suggested or established by other means, such as x-ray; during long-term immobilization; for endocrinopathies known to be associated with osteopenia; for post-gastrectomy and other malabsorption states leading to osteopenia: during long-term corticosteroid therapy; for chronic renal disease, particularly in childhood or adolescence; and to monitor treatment programs for osteoporosis.

Device Description

The accuDEXA device is a Dual Energy X-Ray Absorptiometer (DEXA) device. The device is intended to calculate an index of bone mineral density in the middle finger of the non-dominant hand. By changing the high voltage on the X-ray tube, two energies are produced. Each of the two settings produces an image of the finger and each image is analyzed using various algorithms to produce a value of bone mineral density (BMD) and bone mineral content (BMC). These values are compared with a normative database, yielding a t-score and a z-score. The t-score is the number of standard deviations that the patient is above or below the mean of a reference sample of young healthy individuals. The zscore is the number of standard deviations that the patient is above or below the mean of a reference sample of individuals of the same age as the patient.

AI/ML Overview

Here's an analysis of the provided text regarding the Schick accuDEXA Bone Densitometer, focusing on acceptance criteria and the supporting study:

Schick accuDEXA Bone Densitometer Acceptance Criteria and Study

The provided document, a 510(k) Summary for the Schick accuDEXA Bone Densitometer, describes the device's performance characteristics through a study to demonstrate substantial equivalence to predicate devices. While explicit "acceptance criteria" in a numerical or threshold format are not directly stated, the document implies them through its claims of precision, accuracy, and correlation with predicate devices and ground truth.

1. Table of Acceptance Criteria and Reported Device Performance

Given the nature of a 510(k) submission, the "acceptance criteria" are implied by the demonstration of performance that supports substantial equivalence to existing devices. The document highlights key performance characteristics rather than specific pass/fail values.

Acceptance Criterion (Implied)	Reported Device Performance
Precision (Repeatability)	"The accuDEXA measurements are very repeatable, even with repositioning."
Accuracy	"The very high correlation of the accuDEXA measurements with the ashed bone weights shows that the accuDEXA measurements are very accurate."
Correlation with Predicate Devices	"The good correlation of the accuDEXA measurement with measurements with the two predicate devices demonstrates that the accuDEXA results for the middle finger are at least as good an indicator of BMD as the currently marketed predicate devices."
Ability to Generate Clinical Scores	"A reference data base has been developed in a clinical study which allows the calculation of t-scores and z-scores for each patient."

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

Sample Size for Test Set: The document states the study was conducted "on cadavers" for precision and accuracy testing. It does not specify the exact number of cadavers or bone samples used in this study.
Data Provenance: Retrospective, as it involves cadaveric tissue. The country of origin of the data is not specified.

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

The document does not mention the number or qualifications of experts used to establish ground truth. The ground truth (ashed bone weights) is an objective physical measurement, not an expert interpretation.

4. Adjudication Method for the Test Set

None specified. For the "ashed bone weights" ground truth, adjudication by experts would not be applicable, as it's a direct physical measurement.

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

No. The document does not describe a multi-reader multi-case (MRMC) comparative effectiveness study involving human readers with and without AI assistance. The study focuses on the device's intrinsic performance (precision and accuracy) and its correlation with predicate devices.

6. Standalone Performance Study

Yes. The primary study described evaluates the "precision and accuracy of the accuDEXA device" and its correlation with ashed bone weights. This is a standalone assessment of the algorithmic performance in determining bone density.

7. Type of Ground Truth Used

For the accuracy evaluation, the ground truth used was "ashed bone weights." This is an objective, quantitative physical measurement of true bone mineral content.

8. Sample Size for the Training Set

The document mentions "A reference data base has been developed in a clinical study which allows the calculation of t-scores and z-scores for each patient." However, it does not specify the sample size of this clinical study that formed the normative database.

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

The ground truth for the "reference data base" (which acts as a training set for norm-based scoring) was established through "a clinical study." It is assumed that this clinical study involved measuring BMD in a population to derive mean and standard deviation values for different age, gender, and potentially ethnic groups, thereby establishing the normative data for t-scores and z-scores. The specific methods for establishing the "ground truth" (i.e., true bone density measurements in this clinical cohort) are not detailed beyond "measurements."

Summary

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KIMDS

DEC - 2 1997

510(k) Summary

Schick accuDEXA Bone Densitometer

Common/Classification Name: Bone Densitometer 21 CFR 892.1170

Schick Technologies, Inc. 31-00 47th Avenue Long Island City, NY 11101 718-937-5765, 718-937-5962 (FAX) Contact: Enrico Renzi, Prepared: May 8, 1997

LEGALLY MARKETED PREDICATE DEVICES A.

The accuDEXA is substantially equivalent to bone densitometers The Osteogram Radiographic currently marketed in the U.S. Absorptiometry (RA) device, a pre-Amendment device originally from Compumed (now distributed by Merck), is similar in that it uses the three middle fingers of the hand to compute the bone density, though it uses X-ray film for recording. The Hologic QDR 2000+ DXA bone densitometer (K913321) is similar in that it uses the same dual-energy x-ray absorptiometry (DXA) technology, though it uses the forearm as the measurement site. The Schick CDR Digital Dental X-ray Receptor Array (K933455) currently marketed by Schick Technologies uses a similar digital imaging array.

DEVICE DESCRIPTION B.

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INDICATIONS FOR USE C.

D. SUBSTANTIAL EQUIVALENCE SUMMARY

The intended use for the accuDEXA and the predicate devices is the same. The accuDEXA Bone Densitometer has the same technological characteristics as the predicate devices. However, the descriptive characteristics may not be sufficiently precise to assure substantial equivalence. Therefore, Schick Technologies sponsored performance tests on the device and the predicate devices (see Section F, below), and a comparison of these data demonstrate that the accuDEXA Bone Densitometer is substantially equivalent to the predicate devices.

E. TECHNOLOGICAL CHARACTERISTICS

See Device Description, above.

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TESTING F.

Schick Technologies has sponsored a study on cadavers that examines the precision and accuracy of the accuDEXA device. The study also directly compared the bone density values obtained with the predicate devices. This study showed that the accuDEXA measurements are very repeatable, even with repositioning. The very high correlation of the accuDEXA measurements with the ashed bone weights shows that the accuDEXA measurements are very accurate. The good correlation of the accuDEXA measurement with measurements with the two predicate devices demonstrates that the accuDEXA results for the middle finger are at least as good an indicator of BMD as the currently marketed predicate devices.

A reference data base has been developed in a clinical study which allows the calculation of t-scores and z-scores for each patient.

G. CONCLUSIONS

Schick Technologies has demonstrated through its comparison of characteristics with the predicate devices and comparison of performance testing with the predicate devices that the accuDEXA Bone Densitometer is substantially equivalent to the predicate devices.

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Image /page/3/Picture/0 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is a stylized symbol that resembles three abstract human profiles facing to the right.

DEPARTMENT OF HEALTH & HUMAN SERVICES

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC = 2 1997

Schick Technologies, Inc. c/o T. Whit Athey, Ph.D. Senior Consultant C.L. McIntosh & Associates, Inc. 12300 Twinbrook Parkway, Suite 625 Rockville, Maryland 20852

Re:

K971735 AccuDEXA Bone Densitometer Dated: September 11, 1997 Received: September 11, 1997 Regulatory class: II 21 CFR 892.1170/Procode: 90 KGI

Dear Dr. Athey:

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

We have reviewed your Section 510(k) notification of intent to market the device 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, 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 (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 OS 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 vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. 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 http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

W.Liau 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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KIMDS

DEC - 2 1997

510(k) Summary

Schick accuDEXA Bone Densitometer

Common/Classification Name: Bone Densitometer 21 CFR 892.1170

Schick Technologies, Inc. 31-00 47th Avenue Long Island City, NY 11101 718-937-5765, 718-937-5962 (FAX) Contact: Enrico Renzi, Prepared: May 8, 1997

LEGALLY MARKETED PREDICATE DEVICES A.

DEVICE DESCRIPTION B.

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INDICATIONS FOR USE C.

D. SUBSTANTIAL EQUIVALENCE SUMMARY

E. TECHNOLOGICAL CHARACTERISTICS

See Device Description, above.

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TESTING F.

A reference data base has been developed in a clinical study which allows the calculation of t-scores and z-scores for each patient.

G. CONCLUSIONS

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Image /page/7/Picture/0 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is a stylized symbol that resembles three abstract human profiles facing to the right.

DEPARTMENT OF HEALTH & HUMAN SERVICES

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC = 2 1997

Schick Technologies, Inc. c/o T. Whit Athey, Ph.D. Senior Consultant C.L. McIntosh & Associates, Inc. 12300 Twinbrook Parkway, Suite 625 Rockville, Maryland 20852

Re:

K971735 AccuDEXA Bone Densitometer Dated: September 11, 1997 Received: September 11, 1997 Regulatory class: II 21 CFR 892.1170/Procode: 90 KGI

Dear Dr. Athey:

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

Sincerely yours,

W.Liau 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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STATEMENT OF INDICATIONS FOR USE

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name: Schick accuDEXA Bone Densitometer____________________________________________________________________________________________________________________________

Indications For Use:

The accuDEXA is a dual-energy x-ray device indicated for use in estimating the bone density of the middle finger of the non-dominant hand (BMD). This BMD value is a relative indicator of bone density elsewhere in the body.

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

David A. Siegman

Division Sign-Off) Division of Reproductive, Abdominal, EN and Radiological Devi 510(k) Number

Prescription Use (Per 21 CFR 801.109)

Over-The-Counter Use

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.