The Zio AT device is intended to capture and transmit symptomatic and asymptomatic cardiac events and record continuous electrocardiogram (ECG) data for long-term monitoring. It is indicated for use on patients 18 years or older who may be asymptomatic or who may suffer from transient symptoms such as palpitations, shortness of breath, dizziness, light-headedness, pre-syncope, syncope, fatigue, or anxiety. It is not intended for use on critical care patients.

Device Description

The Zio AT® Electrocardiogram (ECG) Monitoring System is intended for continuous, long-term monitoring of a patient's ECG data with the ability to provide symptomatic and asymptomatic transmissions of potential arrhythmias during wear time. The Zio AT ECG Monitoring System enables ambulatory Mobile Cardiac Telemetry (MCT) services for non-critical care patients by providing the following devices for use. The Zio AT device consists of the Zio AT patch and Zio AT wireless gateway. The Zio AT patch is a single-use ECG monitor applied to the patient's chest, in-clinic or at home, and worn for up to 14 days without any required patient interaction for maintenance, such as replacing or charging a battery. The patch continuously records ECG data and transmits symptomatic and asymptomatic cardiac events through the Zio AT wireless gateway during the wear period. After the wear period concludes, the patient removes and returns the patch to the monitoring center, an Independent Diagnostic Testing Facility (IDTF), for analysis and end-of-wear reporting. The Zio AT wireless gateway securely receives ECG data from the Zio AT patch using Bluetooth technology. The gateway securely transmits ECG data through cellular technology for subsequent processing. The Zio AT device is designed to be used with the interoperable Zio ECG Utilization Service (ZEUS) SaMD which provides an arrhythmia detection algorithm for analysis and reporting.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and study for the Zio AT device, organized as requested:

Device: Zio AT® device (A100A1001)

This premarket notification (K240177) is for an updated version of an already cleared device (Zio® AT ECG Monitoring Device [K240029]). Therefore, the submission primarily focuses on demonstrating substantial equivalence to the predicate device through non-clinical testing rather than presenting new clinical study data with detailed acceptance criteria and performance metrics for the device's diagnostic capabilities. The document explicitly states: "No clinical testing was performed in support of this premarket notification."

As such, many of the requested details related to clinical performance, such as detailed acceptance criteria tables, sample sizes for test sets, expert qualifications, and MRMC studies, are not available in this 510(k) summary. The acceptance criteria described here pertain to safety and engineering standards, not clinical accuracy for arrhythmia detection.

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

Since this is a 510(k) for substantial equivalence based on non-clinical testing for an updated device, the "acceptance criteria" are predominantly for engineering and safety standards, and the "reported performance" is that the device conforms to these standards.

Acceptance Criterion (Type)	Reported Device Performance
System performance testing	Device conforms to specifications and performs as intended.
Biocompatibility testing	Device conforms to ISO 10993-1:2018, ISO 10993-5:2009.
Firmware verification testing	Device conforms to specifications.
Electrical safety and EMC testing	Device conforms to IEC 60601-1:2005/A1:2012, IEC 60601-1-2:2014, and IEC 60601-1-2:2014+A1:2020.
Usability	Device conforms to IEC 60601-1-6:2010/A1:2013+A2:2020 and IEC 62366-1:2015/A1:2020.
Alarm systems	Device conforms to IEC 60601-1-8:2006/A1:2012.
Labeling	Device conforms to ISO 15223-1:2021 (Fourth Edition) and ISO 20417:2021.
Risk Management	Device conforms to ISO 14971:2019.
Medical device software lifecycle	Device conforms to IEC 62304:2006 Ed. 1.1 2015.
Ambulatory ECG systems	Device conforms to IEC 60601-2-47:2012.
General FDA Guidance	Device conforms to Class II Special Controls Guidance (Oct 28, 2003), The 510(k) Program guidance (July 28, 2014), Cybersecurity in Medical Devices guidance (Sept 27, 2023), and Content of Premarket Submissions for Device Software Functions guidance (June 14, 2023).

Regarding the study that proves the device meets the acceptance criteria:

The study referenced is a comprehensive set of nonclinical performance testing. The document states: "All necessary performance testing was conducted on the Zio AT device to ensure performance as intended per specifications and to support a determination of substantial equivalence to the predicate device."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Sample Size for Test Set: Not applicable/not provided for clinical performance. The nonclinical testing involves evaluating the physical device and its software against engineering standards. The sample size would refer to the number of devices or components tested to ensure compliance with specific technical standards (e.g., a certain number of units for electrical safety testing, material samples for biocompatibility), but specific quantities are not detailed in this summary.
Data Provenance: Not applicable, as this is nonclinical (engineering/safety) testing.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable, as this document focuses on nonclinical testing and substantial equivalence, not clinical diagnostic performance requiring expert interpretation as ground truth.

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

Not applicable, as this document focuses on nonclinical testing, not clinical performance where adjudication of "ground truth" labels would be necessary.

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 MRMC comparative effectiveness study was done or reported in this 510(k) summary. This submission explicitly states "No clinical testing was performed in support of this premarket notification." The Zio AT device uses an arrhythmia detection algorithm (provided by the interoperable ZEUS SaMD), but the evaluation here is for the physical device's safety and engineering, not the diagnostic performance of the AI component.

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

This document does not provide details on standalone algorithm performance. The "Zio AT device is designed to be used with the interoperable Zio ECG Utilization Service (ZEUS) SaMD which provides an arrhythmia detection algorithm for analysis and reporting." While an algorithm exists, its performance is not detailed or assessed in this specific 510(k) submission as the focus is on the physical hardware's substantial equivalence to a predicate. Evaluations of the ZEUS SaMD's algorithm (which likely includes standalone performance) would have been part of previous submissions for that software.

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

For the nonclinical testing described, the "ground truth" would be the defined standards and specifications (e.g., a device passes the electrical safety test if it meets the voltage and current limits specified in IEC 60601-1). This is not clinical ground truth.

8. The sample size for the training set

Not applicable/not provided. This submission does not discuss the training of any AI algorithm, as it's a 510(k) for an updated physical device and primarily addresses nonclinical performance and substantial equivalence based on engineering and safety standards.

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

Not applicable/not provided for the same reasons as #8.

Summary

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October 30, 2024

iRhythm Technologies, Inc. Soyini Hamit Senior Regulatory Affairs Program Lead 699 8th Street Suite 600 San Francisco, California 94103

Re: K240177

Trade/Device Name: Zio AT® device (A100A1001) Regulation Number: 21 CFR 870.1025 Regulation Name: Arrhythmia detector and alarm (including ST-segment measurement and alarm) Regulatory Class: Class II Product Code: QYX, DSH, DXH, DXH, DSI Dated: August 13, 2024 Received: August 13, 2024

Dear Soyini Hamit:

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 (the 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 available 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.

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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (OS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled. "Misbranding by reference to premarket notification" (21 CFR 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-regulatory

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assistance/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,

Kimberly N. Crowley -S

For: Jennifer Kozen Assistant Director DHT2A: Division of Cardiac Electrophysiology, Diagnostics, and Monitoring Devices OHT2: Office of Cardiovascular Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

Submission Number (if known)

K240177

Device Name

Zio AT® device (A100A1001)

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)

Prescription Use (Part 21 CFR 801 Subpart D)

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

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iRhythm Technologies, Inc.

Traditional 510(k): 510(k) Summary

510(k) Notification K240177

l. General Information Applicant: iRhythm Technologies, Inc. 699 8th Street, Suite 600 San Francisco, CA 94103 USA Phone: 415-632-5700 Fax: 415-632-5701 Contact Person: Soyini Hamit Sr. Regulatory Affairs Program Lead Phone: 310-571-5418 Email: soyini.hamit@irhythmtech.com Alternate Contact Person: Qiuwei Feng Sr. Director, Regulatory Affairs Phone: 267-798-6382 Email: qiuwei.feng@irhythmtech.com Date Prepared: October 21, 2024 II. Device Information Trade Name: Zio AT® Generic/Common Name: Outpatient Cardiac Telemetry Classification Name Medical magnetic tape recorder [21CFR§870.2800] Telephone electrocardiograph transmitter and receiver [21CFR§870.2920] Arrhythmia detector and alarm (including ST-segment measurement and alarm) [21 CFR§870.1025] Regulatory Class: Class II (Special Controls) Product Codes: QYX, Outpatient Cardiac Telemetry DSH, Recorder, Magnetic Tape, Medical

DXH, Transmitters and Receivers, Electrocardiograph, Telephone

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DSI, Detector and Alarm, Arrhythmia

lll. Predicate Devices

The following predicate device has been selected:

iRhythm Technologies, Inc. Zio® AT ECG Monitoring Device [K240029]

IV. Device Description

The Zio AT ECG Monitoring System enables ambulatory Mobile Cardiac Telemetry (MCT) services for non-critical care patients by providing the following devices for use.

The Zio AT device consists of the Zio AT patch and Zio AT wireless gateway:

Zio AT Patch
The Zio AT patch is a single-use ECG monitor applied to the patient's chest, in-clinic or at home, and worn for up to 14 days without any required patient interaction for maintenance, such as replacing or charging a battery.

The patch continuously records ECG data and transmits symptomatic and asymptomatic cardiac events through the Zio AT wireless gateway during the wear period.

After the wear period concludes, the patient removes and returns the patch to the monitoring center, an Independent Diagnostic Testing Facility (IDTF), for analysis and end-of-wear reporting.

= Zio AT Wireless Gateway
The Zio AT wireless gateway securely receives ECG data from the Zio AT patch using Bluetooth technology. The gateway securely transmits ECG data through cellular technology for subsequent processing.

The Zio AT device is designed to be used with the interoperable Zio ECG Utilization Service (ZEUS) SaMD which provides an arrhythmia detection algorithm for analysis and reporting.

V. Indications for Use

The Indications for Use statement for the Zio AT device is as follows:

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VI. Comparison of Technological Characteristics with Predicate Devices (Substantial Equivalence) The subject and predicate device have the same intended use and similar indications for use statements. The difference in technological characteristics between the subject and predicate Zio AT device are minor and do not raise different questions of safety and effectiveness. Bench testing (non-clinical tests) performed on the subject Zio AT device using the same test methodologies as the predicate, did not identify any issues and further confirm that the device performs as intended.
A comparison table outlining the differences and similarities between the subject device, the Zio AT device, and the predicate device is provided in Table 1.

Feature	Subject Device:	Predicate Device:
	Zio AT device	Zio AT ECG Monitoring System(K240029)
General Characteristics
Classification	Class II	Class II
Classification Regulations	21CFR§870.2800;21CFR§870.2920;21CFR§870.1025	Same
Product Code	QYX, DSH, DXH, DSI	Same
Indications for Use	The Zio AT device is intended tocapture and transmitsymptomatic and asymptomaticcardiac events and recordcontinuous electrocardiogram(ECG) data for long-termmonitoring. It is indicated foruse on patients 18 years orolder who may beasymptomatic or who maysuffer from transient symptomssuch as palpitations, shortnessof breath, dizziness, light-headedness, pre-syncope,syncope, fatigue, or anxiety. It isnot intended for use on criticalcare patients.	Same
Patient Environment	In clinic; At home	Same
Patient Population	18 years and older, non-criticalcare, ambulatory patients	Same
Technological Characteristics
Key System Components	1. Zio AT Patch2. Zio AT Gateway	Same

Table 1: Substantial Equivalence Summary Table

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Event Trigger	Patient-triggered (Button press by the patient for symptomatic events) Auto-trigger (Asymptomatic)	Same
System Communication/Transmission	Short range RF (between patch and gateway) Cellular RF, LTE (between gateway and ZEUS System) Manual/computer interface (between patch and ZEUS System)	Same

VII. Performance Data

There are no required FDA performance standards for the Zio AT device. All necessary performance testing was conducted on the Zio AT device to ensure performance as intended per specifications and to support a determination of substantial equivalence to the predicate device.

Nonclinical testing included:

. System performance testing
Biocompatibility testing
Firmware verification testing
Electrical safety and EMC testing

The scope of the nonclinical testing summarized in Table 2 demonstrates that the Zio AT device is in conformance with FDA recognized consensus standards and FDA guidance documents.

FDA#	Body	Number / Version	Title
19-4	IEC	60601-1:2005/A1:2012	General requirements for basic safety andessential performance for Medical electricalequipment
19-8	IEC	60601-1-2:2014	General requirements for safety – Collateralstandard: Electromagnetic compatibility—Requirements and tests
19-36	IEC	60601-1-2:2014+A1:2020	General requirements for basic safety andessential performance Collateral standard:Electromagnetic compatibility Requirements andtests
5-132	IEC	60601-1-6:2010/A1:2013+A2:2020	General requirements for safety – Collateralstandard: Usability
5-76	IEC	60601-1-8:2006/A1:2012	General requirements for safety – Collateralstandard: General requirements, tests and

Table 2. FDA-Recognized Consensus Standards & Guidance Document Summary

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			guidance for alarm systems in medical electricalequipment
2-258	ISO	10993-1:2018	Biological evaluation of medical devices -Evaluation and testing
2-245	ISO	10993-5:2009	Biological evaluation of medical devices-Part5:Tests for in vitro cytotoxicity
5-134	ISO	15223-1:2021 (FourthEdition)	Symbols to be used with medical device labels,labeling and information to be supplied-Part 1General Requirements
5-125	ISO	14971:2019	Medical devices - Application of riskmanagement to medical devices
5-135	ISO	20417:2021	Medical devices - Information to be supplied bythe Manufacturer
5-129	IEC	62366-1:2015/A1:2020	Medical device - Application of usabilityengineering to medical devices
13-79	IEC	62304:2006 Ed. 1.1 2015	Medical device software – Software lifecycleprocesses
3-155	IEC	60601-2-47:2012	Medical electrical equipment -- Part 2-47:Particular requirements for the basic safety andessential performance of ambulatoryelectrocardiographic systems
N/A	FDA	Class II Special ControlsGuidance Document forIndustry and FDA Staff	Arrhythmia Detector and Alarm (issued October28, 2003)
N/A	FDA	Guidance for Industry andFDA Staff	The 510(k) Program: Evaluating SubstantialEquivalence in Premarket Notifications [510(k)](issued July 28, 2014)
N/A	FDA	Guidance for Industry andFDA Staff	Cybersecurity in Medical Devices: Quality SystemConsiderations and Content of PremarketSubmissions (issued September 27, 2023)
N/A	FDA	Guidance for Industry andFDA Staff	Content of Premarket Submissions for DeviceSoftware Functions (issued June 14, 2023)

VIII. Clinical Testing in Support of Substantial Equivalence Determination

No clinical testing was performed in support of this premarket notification.

IX. Conclusion

The results of the nonclinical testing performed demonstrate that the Zio AT device meets the requirements of established conformance standards and performance specifications necessary for its intended use and does not raise new questions of safety or effectiveness as compared to the predicate device. The Zio AT device is substantially equivalent to the predicate device.

Regulation Number and Section

§ 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm).

(a)
Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to produce a visible or audible signal or alarm when atrial or ventricular arrhythmia, such as premature contraction or ventricular fibrillation, occurs.(b)
Classification. Class II (special controls). The guidance document entitled “Class II Special Controls Guidance Document: Arrhythmia Detector and Alarm” will serve as the special control. See § 870.1 for the availability of this guidance document.