The Fitbit ECG App is a software-only mobile medical application intended for use with Fitbit wrist wearable devices to create, record, store, transfer, and display a single channel electrocardiogram (ECG) qualitatively similar to a Lead I ECG. The Fitbit ECG App determines the presence of atrial fibrillation (AFib) or sinus rhythm on a classifiable waveform. The AFib detection feature is not recommended for users with other known arrhythmias.

The Fitbit ECG App is intended for over-the-counter (OTC) use. The ECG data displayed by the Fitbit ECG App is intended for informational use only. The user is not interpret or take clinical action based on the device output without consultation of a qualified healthcare professional. The ECG waveform is meant to supplement rhythm classification for the purposes of discriminating AFib from normal sinus rhythm and not intended to replace traditional methods of diagnosis or treatment. The Fitbit ECG App is not intended for use by people under 22 years old.

Device Description

The Fitbit ECG App is a software-only medical device used to create, record, display, store and analyze a single channel ECG. The Fitbit ECG App consists of a Device application ("Device app") on a consumer Fitbit wrist-worn product and a mobile application tile ("mobile app") on Fitbit's consumer mobile application. The Device app uses data from electrical sensors on a consumer Fitbit wrist-worn product to create and record an ECG. The algorithm on the Device app analyzes a 30 second recording of the ECG and provides results to the user. Users are able to view their past results as well as a pdf report of the waveform similar to a Lead I ECG on the mobile app.

AI/ML Overview

Below is the information regarding the Fitbit ECG App's acceptance criteria and the study that proves it, based on the provided document:

1. Table of acceptance criteria and the reported device performance

Category	Acceptance Criteria	Reported Device Performance
AFib Detection (Sensitivity)	Not explicitly stated in the provided text as a numerical criterion, but implicitly expected to be high for AFib detection. The predicate device's performance often forms the basis for substantial equivalence.	98.7% for AFib detection
AFib Detection (Specificity)	Not explicitly stated in the provided text as a numerical criterion, but implicitly expected to be high for ruling out AFib. The predicate device's performance often forms the basis for substantial equivalence.	100% for AFib detection
ECG Waveform Morphological Equivalence to Lead I	ECG waveform "qualitatively similar to a Lead I ECG" and expected to meet specific morphological equivalence criteria.	95.0% of AF and SR tracings deemed morphologically equivalent to Lead I of a 12-Lead ECG waveform.

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

Sample Size: 475 subjects.
Data Provenance: Subjects were recruited across 9 US sites. This indicates prospective data collection from the United States.

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

Number of Experts: For subjects with a known history of AFib, a "single qualified physician" performed the screening and assigned them to the AFib cohort. The document doesn't specify how many experts reviewed the 12-lead ECGs for the ground truth of AFib or Sinus Rhythm (NSR) for all 475 subjects, beyond the single physician for the AFib cohort screening. For the overall study, it implies a 12-lead ECG was the reference, which would typically be interpreted by qualified cardiologists or electrophysiologists.
Qualifications of Experts: For AFib screening, the expert was referred to as a "single qualified physician." Specific qualifications like "radiologist with 10 years of experience" are not provided.

4. Adjudication method for the test set

The document does not explicitly state an adjudication method (e.g., 2+1, 3+1). It mentions that subjects with a known history of AFib were screened by a "single qualified physician." For the simultaneous 12-lead ECG, it implies a clinical standard interpretation which often involves adjudicated reads, but this is not detailed in the provided text.

5. If a Multi-Reader, Multi-Case (MRMC) comparative effectiveness study was done

No, a Multi-Reader, Multi-Case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance was not reported in this document. The study focuses on evaluating the standalone performance of the Fitbit ECG App against a clinical standard (12-lead ECG).

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

Yes, a standalone performance study was done. The document states: "The Fitbit ECG App software algorithm was able to detect AF with the sensitivity and specificity of 98.7% and 100%, respectively." This indicates a direct evaluation of the algorithm's performance.

7. The type of ground truth used

The ground truth was established using a simultaneous 30-second 12-lead ECG. This is a clinical gold standard for rhythm analysis.

8. The sample size for the training set

The document does not provide the sample size for the training set. It only details the clinical testing conducted for validation/evaluation of the device.

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

The document does not provide information on how the ground truth for the training set was established, as it focuses on the validation study.

Summary

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September 11, 2020

Fitbit, Inc. Shruti Rajagopalan Medical Regulatory Compliance Manager 199 Fremont Street San Francisco, California 94105

Re: K200948

Trade/Device Name: Fitbit ECG App Regulation Number: 21 CFR 870.2345 Regulation Name: Electrocardiograph software for over-the-counter use Regulatory Class: Class II Product Code: ODA Dated: August 10, 2020 Received: August 11, 2020

Dear Shruti Rajagopalan:

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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

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

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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); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

for

Jennifer Shih Kozen Acting Assistant Director Division of Cardiac Electrophysiology, Diagnostics and Monitoring Devices Office of Cardiovascular Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K200948

Device Name Fitbit ECG App

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)
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Prescription Use (Part 21 CFR 801 Subpart D)

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

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Image /page/3/Picture/0 description: The image shows the Fitbit logo. The logo consists of a stylized, geometric shape made up of small circles on the left side. To the right of the shape is the word "fitbit" in a sans-serif font. There is a registered trademark symbol to the right of the word.

510(k) SUMMARY

Submitter	Fitbit, Inc199 Fremont Ave, 14th Floor,San Francisco, CA 94105
Contact Person:	Shruti Rajagopalan
Phone:	408-242-2515
Email:	shruti.rajagopalan@fitbit.com
Date Prepared:	09 September 2020
Name of Device:	Fitbit ECG App
Common or Usual Name:	Heart Rhythm Assessment, ECG
Regulation Number:	21 CFR§870.2345
Regulation Name:	Electrocardiograph software for over-the-counter use
Regulatory Class:	Class II
Product Code:	QDA
Submission Number	K200948

Predicate Device Information:

Name of Device:	ECG App
Manufacturer:	Apple, Inc.

De Novo Petition Number: DEN180044

Indications for Use

The Fitbit ECG App is a software-only mobile medical application intended for use with Fitbit wrist-wearable devices to create, record, store, transfer, and display a single channel

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Image /page/4/Picture/0 description: The image shows the Fitbit logo. The logo consists of a stylized, geometric shape made up of small circles arranged in a pattern resembling a stylized "F". To the right of the geometric shape is the word "fitbit" in a sans-serif font. The logo is simple, modern, and easily recognizable.

electrocardiogram (ECG) qualitatively similar to a Lead I ECG. The Fitbit ECG App determines the presence of atrial fibrillation (AFib) or sinus rhythm on a classifiable waveform. The AF detection function is not recommended for users with other known arrhythmias.

The Fitbit ECG App is intended for over-the-counter (OTC) use. The ECG data displayed by the Fitbit ECG App is intended for informational use only. The user is not intended to interpret or take clinical action based on the device output without consultation of a qualified healthcare professional. The ECG waveform is meant to supplement rhythm classification for the purposes of discriminating AFib from normal sinus rhythm and not intended to replace traditional methods of diagnosis or treatment. The Fitbit ECG App is not intended for use by people under 22 years old.

Device Description

Summary of Technological Characteristics

	Subject DeviceFitbit ECG App	Predicate DeviceApple ECG app
	K200948	DEN180044
Indications forUse	The Fitbit ECG App is asoftware-only mobile medicalapplication intended for use withFitbit wrist-wearable devices tocreate, record, store, transfer, anddisplay a single channelelectrocardiogram (ECG)qualitatively similar to a Lead IECG. The Fitbit ECG Appdetermines the presence of atrial	The ECG app is a software-onlymobile medical applicationintended for use with the AppleWatch to create, record, store,transfer, and display a singlechannel electrocardiogram (ECG)similar to a Lead I ECG. The ECGapp determines the presence ofatrial fibrillation (AFib) or sinusrhythm on a classifiable waveform.
	fibrillation (AFib) or sinus rhythmon a classifiable waveform. TheAFib detection feature is notrecommended for users with otherknown arrhythmias.The Fitbit ECG App is intended forover-the-counter (OTC) use. TheECG data displayed by the FitbitECG App is intended forinformational use only. The user isnot intended to interpret or takeclinical action based on the deviceoutput without consultation of aqualified healthcare professional.The ECG waveform is meant tosupplement rhythm classificationfor the purposes of discriminatingAFib from normal sinus rhythmand not intended to replacetraditional methods of diagnosis ortreatment. The Fitbit ECG App isnot intended for use by peopleunder 22 years old.	The ECG app is not recommendedfor users with other knownarrhythmiasThe ECG app is intended forover-the-counter (OTC) use. TheECG data displayed by the ECGapp is intended for informationaluse only. The user is not intendedto interpret or take clinical actionbased on the device output withoutconsultation of a qualifiedhealthcare professional. The ECGwaveform is meant to supplementrhythm classification for thepurposes of discriminating AFibfrom normal sinus rhythm and notintended to replace traditionalmethods of diagnosis or treatment.The ECG app is not intended foruse by people under 22 years old.
Mechanism ofOperation	Uses input from consumerwrist-worn devices to detect theelectrical potential differencesbetween the electrical sensors andgenerate an ECG waveform.	Uses input from consumerwrist-worn devices to detectelectrical potential differencesbetween the electrodes and thecrown and generate an ECGwaveform.
DeviceClassification	Class II	Class II
FDA ProductCode andRegulatoryClassification	QDA21 CFR 870.2345	QDA21 CFR 870.2345
Anatomical sites	Left hand fingers to right wrist orvice versa on a consumer gradeelectronic.	Left hand fingers to right wrist orvice versa on a consumer gradeelectronic.
Patientpopulation	Individuals (22 years or older)	Individuals (22 years or older)
Data storage	ECG data stored locally onwrist-worn device untiltransmission to a server.	ECG data stored locally onwrist-worn device untiltransmission to a server.
Prescription/OTC	OTC	OTC
ECG Channels	Single Channel, Lead I	Single Channel, Lead I
User Interface	Device app and Mobile app	Device app and Mobile app
Use Method	Record a 30 second ECG on thewrist-worn device and receiveresults determining the presence ofAtrial Fibrillation or Normal SinusRhythm.	Record a 30 second ECG on thewrist-worn device and receiveresults determining the presence ofAtrial Fibrillation or Normal SinusRhythm.
Results of thealgorithm	Atrial FibrillationNormal Sinus RhythmInconclusive	Atrial FibrillationNormal Sinus RhythmInconclusive
ECG WaveformDisplay	Qualitatively similar to a Lead IECG waveform displayed as a pdfon the Mobile app	Similar to a Lead I ECG displayedas a pdf on the Mobile app

Table 1. Subject and Predicate Device Comparison

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Non-clinical Testing

All necessary performance testing was conducted on the Fitbit ECG App to support a determination of substantial equivalence to the predicate device. This testing included testing of input signal quality as per IEC 60601-2-47:2012 Medical Electrical Equipment -Ambulatory Electrocardiographic Systems. Testing was conducted using appropriate databases from ANSI/AAMI EC57:2012.

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Image /page/7/Picture/0 description: The image shows the Fitbit logo. The logo consists of a stylized, geometric shape made up of small circles arranged in a pattern resembling a stylized letter 'F' or a diamond shape. To the right of the geometric shape is the word "fitbit" in a sans-serif font. A small circle with an 'R' inside is located to the right of the word.

Human Factors Testing

Human Factors testing was performed to demonstrate that the user can correctly use the device by solely reading the device labeling and also correctly interpret the device output and understand when to seek medical care. This testing satisfies the special control requirements of the predicate device and provides evidence of substantial equivalence.

Clinical Testing

Clinical testing was performed similar to the predicate device. 475 subjects, with and without a known diagnosis of AFib, were recruited to participate across 9 US sites. Eligible subjects underwent a 10-second screening using a 12-lead ECG. Subjects with a known history of AFib were screened for AFib by a single qualified physician and assigned to the AFib cohort. Subjects without a known history of AFib were screened for NSR and assigned to the NSR cohort. Subsequently, subjects underwent a simultaneous 30-second 12-lead ECG and Fitbit ECG App test. The Fitbit ECG App software algorithm was able to detect AF with the sensitivity and specificity of 98.7% and 100%, respectively. The Fitbit ECG App's single lead waveform was deemed morphologically equivalent to the Lead I of a 12-Lead ECG waveform overall for 95.0% of AF and SR tracings reviewed qualitatively. The qualitative and quantitative results of the clinical study demonstrated substantial equivalence.

Conclusions

The Fitbit ECG App is similar in technological characteristics and has the same intended use as the Apple ECG app. Differences in technological characteristics have been evaluated through performance testing including the special controls requirements of the predicate which has shown that the minor technological differences between the Fitbit ECG App and the predicate device raise no new issues of safety or effectiveness. Bench and clinical data demonstrate that the Fitbit ECG App is substantially equivalent to the Apple ECG App.

Regulation Number and Section

§ 870.2345 Electrocardiograph software for over-the-counter use.

(a)
Identification. An electrocardiograph software device for over-the-counter use creates, analyzes, and displays electrocardiograph data and can provide information for identifying cardiac arrhythmias. This device is not intended to provide a diagnosis.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Clinical performance testing under anticipated conditions of use must demonstrate the following:
(i) The ability to obtain an electrocardiograph of sufficient quality for display and analysis; and
(ii) The performance characteristics of the detection algorithm as reported by sensitivity and either specificity or positive predictive value.
(2) Software verification, validation, and hazard analysis must be performed. Documentation must include a characterization of the technical specifications of the software, including the detection algorithm and its inputs and outputs.
(3) Non-clinical performance testing must validate detection algorithm performance using a previously adjudicated data set.
(4) Human factors and usability testing must demonstrate the following:
(i) The user can correctly use the device based solely on reading the device labeling; and
(ii) The user can correctly interpret the device output and understand when to seek medical care.
(5) Labeling must include:
(i) Hardware platform and operating system requirements;
(ii) Situations in which the device may not operate at an expected performance level;
(iii) A summary of the clinical performance testing conducted with the device;
(iv) A description of what the device measures and outputs to the user; and
(v) Guidance on interpretation of any results.