The KRELL Weight & Body Fat Monitoring Scale is indicated to measure body weight and impedance and estimate the percentage of Body Fat and body water, Bones mass using BIA (bioelectrical impedance analysis). This product is for use by generally healthy adults and children (from age 10 and up) who are not ill, feverish, have a chronic or acute disease, or a condition that affects the level of hydration such as pregnancy.

Device Description

The patient steps on the scale device, where two electrodes are located. The patient must step on the electrodes with bare feet, with normal moisture. Through harmless current stimulation of 500 µA, at 50 kHz, the Krell Body Fat Analyzer calculates the body fat percentage. This calculation is done via the Bioelectrical Impedance Method. The current is passed through the body and the impedance of the body determines the body fat. The calculation is based upon electrical impedance, height, age. and gender. The calculation is performed via internal software, which uses the variables programmed in by the user. There are elements of this process that can produce erroneous readings, such as dry feet or improperprogrammed data. The User's Manual defines items which could cause erroneous readings.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information based on the provided document:

Acceptance Criteria and Device Performance

The document states that "Clinical testing was used to validate the effectiveness and accuracy of the device. All test results were satisfactory." However, it does not provide specific numerical acceptance criteria for accuracy or effectiveness, nor does it present detailed performance metrics other than the general statement that results were "satisfactory."

Without explicit targets, it's impossible to create a table comparing acceptance criteria to reported device performance. The submission relies primarily on demonstrating substantial equivalence to predicate devices (Tanita BC-533, K040778; Bonso Health o meter BMF583, K030349) rather than establishing and meeting quantitative performance goals for a de novo device.

Study Details

Here's what can be extracted about the study from the provided 510(k) summary:

Sample size used for the test set and the data provenance:
- Sample Size: Not specified in the document.
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). The device company is based in China, but the location of the clinical testing is not mentioned. It is implied to be prospective clinical testing to "validate the effectiveness and accuracy of the device."
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not specified. The document only mentions that the Bioelectrical Impedance Method "has been validated via DXA (Dual Energy X-Ray Absorptiometry)," implying DXA was used as the ground truth. However, details on who performed or interpreted the DXA scans, or their qualifications, are not provided in the context of this specific device's validation study.
Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not specified.
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 device is a standalone body fat and weight scale, not an AI-assisted diagnostic tool that would involve human readers or comparative effectiveness studies of this type.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone study was done. The device operates as a standalone unit, calculating body fat percentage via its internal software using Bioelectrical Impedance through electrodes. The clinical testing mentioned in point 8 ("Clinical testing was used to validate the effectiveness and accuracy of the device") supports this standalone performance.
The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The document states, "This bioelectrical impedance method has been validated via DXA (Dual Energy X-Ray Absorptiometry)." This indicates that DXA (Dual Energy X-Ray Absorptiometry) was used as the ground truth for validating the bioelectrical impedance method. DXA is a well-established method for measuring body composition, including body fat.
The sample size for the training set:
- Not specified. While the device uses internal software, the document treats the Bioelectrical Impedance Method itself as having been previously validated, rather than detailing a specific training set for this device's algorithm.
How the ground truth for the training set was established:
- Not specified. Assuming the "bioelectrical impedance method" was itself developed and validated, the ground truth would have been established through methods like DXA in those earlier validation efforts, but this document does not provide details specific to the training of this particular device's internal software.

Summary of Missing Information:

It's important to note that the provided 510(k) summary is quite brief on the details of the clinical validation study. Common information expected in such submissions, like specific sample sizes, demographic breakdowns of study participants, detailed performance metrics (e.g., mean absolute error, correlation coefficients, or agreement rates with DXA), and specific acceptance criteria, are not present. The submission relies more on the general statement of "satisfactory" test results and the established validity of the BIA method, along with substantial equivalence to predicate devices.

Summary

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4081587 PAGE 1 OF 3

510(k) Summary

OCT 2 4 2008

This summary of 510(k) safety and effectiveness information is being submitted in accordance with requirements of 21 CFR Part 807.92.

Date: March 11, 2007

1. Company and Correspondent making the submission:

Name Krell Precision (Yang Zhou) Co., LTD
Address Number 28, Xing Yang Road, Yang Zhou, Jiang Su Province,
China

Telephone -- +86(0)514-87961819

Fax - +86(0)514-87961918

Contact Mike Zheng
Email mike zheng@krellprecision.com
1. Device :

Trade/proprietary name: KRELL WEIGHT AND BODY FAT SCALE/BFA-

8530

Common Name	: Analyzer, Body Fat
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Classification Name : Impedance plethysmograph

1. Predicate Devices :
  Tanita BC-533, (K040778); Bonso Health o meter BMF583
1. Classifications Names & Citations :
  21CFR 870.2770, MNW, Body Fat Analyzer, Class2

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5. Description :

5.1 General
The patient steps on the scale device, where two electrodes are located. The patient must step on the electrodes with bare feet, with normal moisture. Through harmless current stimulation of 500 µA, at 50 kHz, the Krell Body Fat Analyzer calculates the body fat percentage. This calculation is done via the Bioelectrical Impedance Method. The current is passed through the body and the impedance of the body determines the body fat. The calculation is based upon electrical impedance, height, age. and gender. The calculation is performed via internal software, which uses the variables programmed in by the user. There are elements of this process that can produce erroneous readings, such as dry feet or improperprogrammed data. The User's Manual defines items which could cause erroneous readings.

This bioelectrical impedance method has been validated via DXA (Dual Energy X-Ray Absorptiometry).

5.2 Direction

As discussed in the General description, the Krell Body Fat Analyzer is relatively simple to use. The user inputs the variable data of age, height, and gender. The user steps onto the scale and the devices measures the user weight and body impedance (via the Bioelectric Impedance through the two electrodes on the scale). The scale displays the user's body fat composition. Upon the user's selection, the device can also display the user's weight.

6. Indication for use :

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1. Comparison with predicate device :
  Krell Precision (Yang Zhou) Co., LTD, believes that the Krell Weight and Body Fat Scale is substantially equivalent to the Tanita BC-533 (K040778), Bonso Health o meter Model BFM583 (K030349)
1. Safety and Performance Data :
  Electrical, mechanical, environmental safety and performance testing according to standard EN/IEC 60601-1. Clinical testing was used to validate the effectiveness and accuracy of the device. All test results were satisfactory.

CF 2

1. Conclusions:
  In accordance with the Federal Food, Drug and Cosmetic Act, 21 CFR Part 807 and based on the information provided in this premarket notification Krell. Inc. concludes that The Krell Weight and Body Fat Scale is safe and effective and substantially equivalent to predicate devices as described herein.
1. Krell Precision (Yang Zhou) Co., LTD will update and include in a summary any other information deemed seasonably necessary by the FDA.
  END

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the seal for the Department of Health & Human Services - USA. The seal is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. In the center of the seal is an abstract image of an eagle.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

OCT 2 4 2008

Krell Precision (Yang Zhou) Co., Ltd. c/o Mr. Charles Mack Principal Engineer International Regulatory Consultants, LLC 340 Shady Grove Road FLINTVILLE TN 37335

Re: K081587

Trade/Device Name: KRELL Weight & Body Fat Monitoring Scale, Model BFA-8530 Regulation Number: 21 CFR §870.2770 Regulation Name: Impedance plethysmograph Regulatory Class: II Product Code: MNW Dated: October 12, 2008 Received: October 20, 2008

Dear Mr. Mack:

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 such 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 conceming your device in the Federal Register.

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Page 2

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 (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 this letter:

21 CFR 876.xxx	(Gastroenterology/Renal/Urology)	240-276-0115
21 CFR 884.xxx	(Obstetrics/Gynecology)	240-276-0115
21 CFR 894.xxx	(Radiology)	240-276-0120
Other		240-276-0100

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807,97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometrics' (OSB's) Division of Postmarket Surveillance at 240-276-3474. For questions regarding the reporting of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at 240-276-3464. You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers. International and Consumer Assistance at its toll-free number (800) 638-2041 or (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

Jorgu M. Whang

Joyce M. Whang, Ph.D Acting Director. Division of Reproductive. Abdominal, 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):

K081587

Device Name: Weight & Body Fat Monitoring Scale (Model BFA-8530)

Indications For Use:

Prescription Use (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use X (21 CFR 801 Subpart C)

(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 Sign-Off)
Division of Reproductive, Abdominal,
and Radiological Devices
510(k) Number K081587

Page 1 of 1

Regulation Number and Section

§ 870.2770 Impedance plethysmograph.

(a)
Identification. An impedance plethysmograph is a device used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs.(b)
Classification. Class II (special controls). The device, when it is a body composition analyzer which is not intended to diagnose or treat any medical condition, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.