The ARIA WiFi Smart Scale is a body analyzer that measures body weight and uses bioelectrical impedance analysis (BIA) technology to estimate body fat percentage in generally healthy individuals 10 years of age or older. It is intended for home use only.

Device Description

ARIA is a body weight scale and a body fat analyzer that operates by using a low, safe, battery-generated electrical current through the body (using a bioelectrical impedance analysis technique) to provide body fat and body weight information. After the user registers their scale, the scale automatically recognizes the subject based on body weight and body fat readings. ARIA contains a WiFi module (802.11 module) that allows it to connect to the Internet in the user's home. The module provides a complementary interface to the Fitbit website. Body weight and body fat measurements are independent of internet communication after initial product registration.

The ARIA scale automatically measures body weight and body fat composition. The scale recognizes the user based on previous weight readings, and can accept up to eight (8) different users. The 16 most recent readings are kept in memory on the scale and readings are also transmitted to the user's optional fitbit.com personal account for trending. If users have similar weight, the proper identity can be selected by tapping the scale.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the Fitbit ARIA WiFi Smart Scale, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria for the ARIA WiFi Smart Scale are established not through explicit numerical thresholds but by demonstrating substantial equivalence to a predicate device (Withings Smart Body Scale K121971) and showing that its body fat measurements are not statistically different from the predicate, with variation within an acceptable range.

Feature/Metric	Acceptance Criteria (Implied from Predicate/Study)	Reported Device Performance
Substantial Equivalence	Demonstrates equivalence in technology, intended use, classification, product code, indication for use, device description, analysis method, operating parameters, number of electrodes, power source, IP connectivity, and measured parameters to the predicate device (Withings WBS01 Smart Body Scale K121971).	The ARIA WiFi Smart Scale is listed as substantially equivalent to the Withings Smart Body Scale (K121971) across all listed features. Differences noted (e.g., age range, specific power source type, minor IP connectivity details) are presented as not impacting substantial equivalence.
Body Fat Measurement	Body fat composition (%) measurements should not be statistically different (p>0.05) from the predicate device, and body fat measurements should vary by < 8% from one another when compared to the predicate device.	"Results of this study lead to the conclusion that the measurements from ARIA were not statistically different from the predicate device (p>0.05) and body fat measurements varied by <8% from one another."
Safety and EMC	Compliance with IEC 60601-1 (medical electrical equipment safety) and IEC 60601-1-2 (electromagnetic compatibility).	"The ARIA WiFi Smart Scale has been tested according to IEC 60601-1, IEC 60601-1-2 and was found to meet all requirements."
Reliability & Human Factors	Meet specified criteria as per internal testing.	"Performance data (reliability testing and human factors testing) also support that the ARIA device meet its specified criteria." (Specific criteria not detailed in the summary).

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

Sample Size for Test Set: 50 subjects (25 male and 25 female).
Data Provenance: The study was a "small comparative clinical study" comparing the ARIA WiFi Smart Scale to the predicate device. The text does not specify the country of origin but implies it was conducted by the manufacturer or a contracted clinical research organization. The study design strongly suggests it was prospective as it involved collecting new data for direct comparison between the two devices.

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

The study does not establish an independent "ground truth" against which the device performance is measured in the classical sense (e.g., DEXA or underwater weighing). Instead, the performance of the ARIA device is compared directly against the predicate device (Withings Smart Body Scale K121971) as the reference. Therefore, there were no experts used to establish a separate ground truth for the test set. The predicate device's measurements serve as the comparator.

4. Adjudication Method for the Test Set

Not applicable. This was a direct comparison study between a new device and a predicate device. There was no complex labeling or interpretation by multiple human readers requiring adjudication. The study involved objective measurements of body fat percentage from both devices.

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

No, an MRMC comparative effectiveness study was not done. This device (Fitbit ARIA WiFi Smart Scale) is a standalone measurement device for body weight and body fat, not an AI-assisted diagnostic tool that aids human readers. The study performed was a direct comparison of its measurement accuracy against a predicate device.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, a standalone performance study was done. The clinical performance testing compared the ARIA WiFi Smart Scale's measurements of body fat composition directly against the measurements from the predicate device. This is a standalone comparison as it assesses the device's output independently. The device's primary function is to measure and display these values, which are then transmitted to a user's account for tracking, but the core performance evaluation focuses on the accuracy of these direct measurements.

7. The Type of Ground Truth Used

The "ground truth" for the clinical performance study was the measurements obtained from the predicate device (Withings Smart Body Scale K121971). The study aimed to demonstrate that the ARIA device's measurements were not statistically different from those of the legally marketed predicate device. While BIA is an estimation method itself, for the purpose of demonstrating substantial equivalence, the predicate device's output serves as the comparative reference.

8. The Sample Size for the Training Set

The document does not mention a training set or any machine learning/AI model that would require a distinct training set. The ARIA WiFi Smart Scale uses Bioelectrical Impedance Analysis (BIA) technology, which is a well-established method, not typically relying on a separately described "training set" in the context of regulatory submissions for this type of device. The description focuses on its sensor technology and comparison to a predicate.

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

As no training set is mentioned or implied for a machine learning model, this question is not applicable. The device relies on physical principles of bioelectrical impedance.

Summary

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K133872 Page 1 of 2

fitbit

JUN 0 2 2014 510(k) Summary of Safety and Effectiveness

Manufacturer and Submitter

Company Name:	Fitbit, Inc.
Company Address:	150 Spear Street, Suite 200San Francisco, CA 94015Tel 1.650.333.4001
Contact Person:	Arndt Hufenbach
Date Summary Prepared:	December 2013

Device Name and Classification

Trade/Device Name:	ARIA WiFi Smart Scale
Common/Usual Name:	Analyzer, Body Composition
Classification Name:	Impedance Plethysmograph
Regulation Number:	21 CFR §870.2770
Product Code:	MNW
Classification Panel:	Cardiovascular Devices
Classification:	Class II

Substantial Equivalence

This 510(k) submission demonstrates that the ARIA WiFi Smart Scale is substantially equivalent to the Smart Body Scale (Withings, K121971) in both technology and intended use.

Feature	ARIA WiFi Smart ScaleNew Device	Withings Smart Body Scale(Predicate) K121971
Classification	21 CFR 870.2770	21 CFR 870.2770
Product Code	MNW	MNW
Indication for Use	The ARIA WiFi Smart Scale isa body analyzer that measuresbody weight and usesbioelectrical impedanceanalysis (BIA) technology toestimate body fat percentagein generally healthy individuals10 years of age or older. It isintended for home use only.	The Withings WBS01 SmartBody Scale measures weightand uses bioelectricalimpedance analysis (BIA)technology to estimate bodyfat mass in generally healthyadults 18 years of age orolder. It is intended for use inthe home/domestic settingonly.
Device Description	Fitbit ARIA WiFi Smart Scaleuses a "foot-to-foot"bioelectrical impedanceanalysis (BIA) technology todetermine internal bodycomposition	Withings WBS01 Smart BodyScale utilizes a "foot-to-foot"bioelectrical impedanceanalysis (BIA) technology todetermine internal bodycomposition
Analysis method	BIA (Bioelectrical ImpedanceAnalysis)	BIA (Bioelectrical ImpedanceAnalysis)
Operating parameters	50 KHz	50 KHz

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K133872 Page 2 of 2

Feature	ARIA WiFi Smart ScaleNew Device	Withings Smart Body Scale(Predicate) K121971
Number of electrodes	4	4
Power Source	4-AA	4-AAA
Operating Keys	None	No operating key, 1 unitswitch, 1 pairing button
IP Connectivity	802.11b (WiFi)	802.11b/g (WiFi)
Parameters Measured	Body weight, Body fatcomposition	Body weight, Body fatcomposition

Device Description

Intended Use/Indications for Use

Performance - Bench Testing

The ARIA WiFi Smart Scale has been tested according to IEC 60601-1, IEC 60601-1-2 and was found to meet all requirements. Performance data (reliability testing and human factors testing) also support that the ARIA device meet its specified criteria.

Performance - Clinical Performance Testing

A small comparative clinical study was conducted to compare body fat composition (%) in 25 male and 25 female subjects using the ARIA WiFi Smart Scale vs. the predicate device. This study was conducted in generally healthy subjects (without acute or chronic illness, disease, or condition such as pregnancy). Results of this study lead to the conclusion that the measurements from ARIA were not statistically different from the predicate device (p>0.05) and body fat measurements varied by <8% from one another.

Date of summary: April 2, 2014

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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 circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract symbol that resembles an eagle or bird in flight, composed of three curved lines.

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

June 2, 2014

Fitbit, Inc. % Diane Horwitz, Ph.D. Regulatory Affairs Consultant Mandell Horwitz Consultants, LLC 2995 Steven Martini Drive Fairfax, VA 22031

Re: K133872 Trade/Device Name: ARIA WiFi Smart Scale Regulation Number: 21 CFR§ 870.2770 Regulation Name: Impedance plethysmograph Regulatory Class: II Product Code: MNW Dated: April 4, 2014 Received: April 4, 2014

Dear Diane Horwitz,

We have reviewed your Section 510(k) premarket notification of intent to market the indication We have reviewed your Section 310(t) premaited is substantially equivalent (for the indications
referenced above and have determined the device is subscreenced in interstate referenced above and have determined the devices noredicate devices marketed in interstate for use stated in the encrosine) to legally manced provide Medical Device Amendments, or to commerce prior to May 28, 1970, the chance with the provisions of the Federal Food, Drug, devices that have been recolusined in accordance with approval application (PMA).
and Cosmetic Act (Act) that do not require approval of a provisions of the Act . The and Cosmetic Act (Act) that do not require approval or a provisions of the Act. The Act. The
You may, therefore, market the device, subject to the general cannus massessio You may, therefore, market the device, subject to the gentralize annual registration, listing of
general controls provisions of the Act include requirements michmoding and general controls provisions of the Fet mendate required misbranding and devices, good manufacturing practice, labelian information related to contract liability.
adulteration. Please note: CDRFI does not evaluate in the success to tracted adulteration. Please note: CDNFI does not evaluate information of misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it
in be If your device is classified (sec and of microsoft (spines affecting your device can be
may be subject to additional controls. Exist 800 to addition FDA may may be subject to additional controls. Existing major regardent on and interest of and in the corporations of the may be found in the Code of Tederal Regilations, This 20, vice in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean Please be advised that FDA s issualice of a substination with other requirements of the Act
that FDA has made a determination that your device with other agencies that FDA has made a determination mavy only other Federal agencies.

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Page 2 - Diane Horwitz, Ph.D.

You must comply with all the Act's requirements, including, but not limited to: registration and I va must compy man 7); labeling (21 CFR Part 801); medical device reporting (reporting of nsting (21 CFR ratt 007), accomig (2) CFR 803); good manufacturing practice requirements micular device-related as velos of the regulation (21 CFR Part 820); and if applicable, the as set form in the quality of control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please If you desire specific advice to: your dorners offices/CDRH/CDRHOffices/ucm115809.htm for go to mp3/7www.ba.gov/About D7. Corners) Office of Compliance. Also, please, and Radio Color Collection (2010) Port the Center for Devices and Radionaling by reference to premarket notification" (21CFR Pation (1 note the regulation entined, "Misoraneing of restrative of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the You may obain other general information on your icopediater Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address (800) 030-2041 of (501) 770 7700 er un no mores for You/Industry/default.htm.

Sincerely yours,

Image /page/3/Picture/6 description: The image shows the name "Benjamin R Fisher-S" in a stylized font. The text is mostly black, with some parts of the letters filled with a pattern of smaller text or symbols. The overall impression is of a logo or signature.

Benjamin R. Fisher, Ph.D. Director Division of Reproductive, Gastro-Renal, and Urological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): _K133872

ARIA WiFi Smart Scale Device Name:

Indications For Use:

The ARIA WiFi Smart Scale is a body analyzer that measures body weight and The ARTA WIFT Smart Scale is a bouj unling to estimate body fat uses bloelectively individuals 10 years of age or older. It is intended for home use only.

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

× Over-The-Counter Use (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)

Benjamin R. Fisher -2014.06.02 21:44:47 -04'00'

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.