The HearTwave II Cardiac Diagnostic System is intended for the recording of electrocardiograms, vector cardiograms and measurement of Microvolt T-Wave Alternans* at rest and during ECG stress testing.

The presence of Microvolt T-wave Alternans as measured by the HearTwave II Cardiac Diagnostic System in patients with known, suspected or at risk of ventricular tachyarrhythmia predicts increased risk of a cardiac event (ventricular tachyarrhythmia or sudden death).

The HearTwave II Cardiac Diagnostic System should be used only as an adjunct to clinical history and the results of other non-invasive and/or invasive tests. The interpretive results of the Alternans Processing System should be reviewed by a qualified physician.

The predictive value of T-wave Alternans for cardiac events has not been established in patients with active, untreated ischemia.

*Microvolt T-wave Alternans is defined as T-wave alternans which (a) is measured from high-resolution multi-segment sensors, (b) is present in leads X, Y, Z, VM or two adjacent precordial leads, (c) is at the level of 1.9 microvolts after signal optimization and subtraction of the background noise level, (d) is at least three standard deviations greater than the background noise level, (e) has an onset heart rate at or below 110 beats per minute, and (f) is sustained for all heart rates above the onset heart rate.

Device Description

The Cambridge Heart HearTwave II Cardiac Diagnostic System is intended for the measurement and recording of T-Wave alternans. The alternans levels reported in K983012, K001034, K003492 and K022149 were measured using the Analytic Spectral Method. This method consists of several computational steps that combine to form a unique analytical process. The Microvolt T-wave Alternans measurement, the output of this specific process, has been shown to be useful in predicting ventricular tachyarrhythmias and sudden cardiac death.

The Cambridge Heart HearTwave II Cardiac Diagnostic System provides T-wave alternans diagnostic capabilities to standard stress labs. The Analytic Spectral Method of Alternans Processing used in the Cambridge Heart HearTwave II is intended for the measurement of microvolt T-Wave alternans at rest and during treadmill, ergometer and pharmacologic stress testing.

The Alternans test using the Cambridge Heart HearTwave II is performed with seven standard stress test electrodes and seven proprietary multi-segment Micro-V Alternans™ Sensors. The electrodes and sensors are attached through a leadwire set to the beltworn Patient module, which provides digitized data to the HearTwave II.

AI/ML Overview

The provided document does not contain explicit acceptance criteria or a study proving the device meets specific performance criteria beyond general performance standards. This 510(k) submission primarily focuses on establishing substantial equivalence to a predicate device (K022149, the HearTwave II Cardiac Diagnostic System) for a modification, rather than detailing a new performance study with acceptance criteria.

The document indicates that the HearTwave II Cardiac Diagnostic System uses the same Analytic Spectral Method as the predicate device (CH2000, K022149) for measuring T-Wave Alternans. Therefore, the performance characteristics are presumed to be largely similar to the predicate.

Here's an analysis of the provided text in relation to your request:

1. Table of Acceptance Criteria and Reported Device Performance:

No explicit acceptance criteria (e.g., specific sensitivity, specificity, accuracy targets) are provided in this document. The submission focuses on compliance with general performance standards for medical electrical equipment and ECG devices.
No specific device performance metrics (e.g., sensitivity, specificity, PPV, NPV) are reported for this specific 510(k) submission. The document states "The Microvolt T-wave Alternans measurement, the output of this specific process, has been shown to be useful in predicting ventricular tachyarrhythmias and sudden cardiac death," but does not provide new performance data to support this for the modified device. It likely refers to studies done on prior versions of the system.

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

Not specified. The document does not describe a new test set or data used for an independent performance evaluation for this 510(k) submission.

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

Not applicable/Not specified. Since no new performance study with a test set is detailed, information about experts for ground truth is not provided.

4. Adjudication Method for the Test Set:

Not applicable/Not specified. As no new performance study is detailed, no adjudication method is mentioned.

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

No. The document does not describe an MRMC study or any assessment of human-AI collaboration for this submission. The device appears to be an analytical tool, not primarily an AI-assisted diagnostic tool in the sense of image interpretation.

6. Standalone (Algorithm Only) Performance Study:

Implied, but no new study is reported in this document. The "Analytic Spectral Method" is an algorithm. The 510(k) states: "The HearTwave II Cardiac Diagnostic System uses the same Analytic Spectral Method as the CH2000 (K02149) for measuring T-Wave Alternans." This suggests the standalone performance was established for the predicate device, but no new standalone study specific to this K050225 modification is detailed.

7. Type of Ground Truth Used:

Not specified for this submission. For the predicate device's original validation of its predictive value, the ground truth would likely have been clinical outcomes data (e.g., confirmed ventricular tachyarrhythmia or sudden cardiac death). However, this document does not detail how ground truth was established for the claims made.

8. Sample Size for the Training Set:

Not specified. The document does not mention any training sets for machine learning models as it describes a specific "Analytic Spectral Method" rather than a trained AI model in the contemporary sense. If the "Analytic Spectral Method" has tunable parameters, how those parameters were determined (e.g., "signal optimization," "subtraction of the background noise level") would be relevant, but this information is not provided.

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

Not applicable/Not specified.

Summary of what is present in the document:

Indications for Use: The system records ECGs, vector cardiograms, and measures Microvolt T-Wave Alternans at rest and during stress testing. The presence of Microvolt T-wave Alternans (as defined by specific criteria) predicts increased risk of cardiac events in specific patient populations.
Definition of Microvolt T-wave Alternans: This is a crucial "acceptance criteria" for the measurement itself, detailing conditions like amplitude (1.9 microvolts after signal optimization), statistical significance (three standard deviations above noise), and heart rate conditions. This is a definition of a positive finding by the device, not an acceptance criterion for the device's overall performance (e.g., accuracy against a clinical outcome).
Device Description: It uses an "Analytic Spectral Method" for T-wave alternans processing, which is stated to be the same as the predicate device.
Performance Standards: The device is designed to meet various national and international safety and electrical performance standards (e.g., ANSI/AAMI EC11-1991, EN60601 series, IEC 60601 series, FDA guidances). These are engineering standards, not clinical performance metrics.
Substantial Equivalence: The primary assertion of the 510(k) is that the modified HearTwave II Cardiac Diagnostic System is "essentially the same device" as the predicate (K022149) with respect to the T-wave Alternans measurement method. This implies that the performance characteristics of the predicate are sufficient and apply to the modified device.

Summary

{0}------------------------------------------------

05-0225

APR 7 2005

510(k) Summary

January 31, 2005

Submitter: Cambridge Heart, Inc 1 Oak Park Bedford, Ma 01730 (781) 271-1200 (781) 275-8431

Contact: Dave Chazanovitz

510(k) Numbers and Product Codes of equivalent devices:

Cambridge Heart, Inc .; HearTwave II Cardiac Diagnostic System

510(k) Number: # K022149

Product Code: 74 DPS

CFR Section: 870.2340

Indications for Use and Intended Population

The presence of Microvolt T-wave Alternans as measured by the analytic spectral method of the HearTwave II Cardiac Diagnostic System in patients with known, suspected or at risk of ventricular tachyarrhythmia predicts increased risk of a cardiac event (ventricular tachyarrhythmia or sudden death).

The Cambridge Heart HearTwave II Cardiac Diagnostic System should be used only as an adjunct to clinical history and the results of other non-invasive and/or invasive tests.

The predictive value of T-wave Alternans for cardiac events has not been established in patients with active, untreated ischemia.

Device Description

HearTwave II Cardiac Diagnostic System Special 510(k) Pre-market Submission Section 4.0 - 510(k) Summary page 1

Ong

{1}------------------------------------------------

K050225

unique analytical process. The Microvolt T-wave Alternans measurement, the output of this specific process, has been shown to be useful in predicting ventricular tachyarrhythmias and sudden cardiac death.

Patient Electrodes:

Patient electrodes designed and approved specifically for use during exercise stress testing should be used at all times with the Cambridge Heart Model HearTwave II Cardiac Diagnostic System.

Measurement of alternating beat to beat T-wave amplitude (alternans) requires the use of the Cambridge Heart Hi-Res Electrode (Ref: # K962115) or The Cambridge Heart Micro-V Alternans Sensor (Ref: #K002230) in conjunction with other Patient electrodes designed and approved specifically for use during exercise stress testing.

Performance Standards

The Cambridge Heart HeartWave II Cardiac Diagnostic System is designed to meet the following Performance Standards:

ANSI/AAMI EC11-1991 .
EN60601-1: 2004, "Medical Electrical Equipment, Part 1: General Requirements . for Safety" including Amendments A1 and A2
EN60601-1-1: 2000, "Medical Electrical Equipment, Part 1: General . Requirements for Safety - Section 1.1 Collateral standard: Safety requirements for medical electrical systems"
EN60601-1-2: 2004, "Medical Electrical Equipment, Part 2: Collateral Standard: . Electromagnetic Compatibility - Requirements and Tests"
EN60601-1-4: 2000, "Medical Electrical Equipment, Programmable Medical . Systems"
IEC 60601-2-25: 1993, "Particular requirements for the safety of ● electrocardiographs" including Amendment 1
. IEC 60601-2-51: 2003 "Particular requirements for safety, including essential performance, of recording and analyzing single and multichannel electrocardiographs

HearTwave II Cardiac Diagnostic System Special 510(k) Pre-market Submission Section 4.0 - 510(k) Summary page 2

{2}------------------------------------------------

FDA Diagnostic ECG Guidance: 1998, Version 1.0 .
FDA Electrocardiograph Lead Switching Adaptor Guidance: 1997, Version 1.0 .
FDA Guidance For Industry: 2000 " General Principles of Software Validation" .
FDA Guidance For Industry: 1999 " Guidance for Off-The -Shelf Software for use . in Medical Devices"
ISO 14971: 2000 " Application of risk management to medical devices" .

K050225

Similarities and Differences to Predicates

The Model HearTwave II Cardiac Diagnostic System (new) is essentially the same device as in K02149 with the exception of the modification described in this premarket submission. The Model HearTwave II Cardiac Diagnostic System uses the same Analytic Spectral Method as the CH2000 (K02149) for measuring T-Wave Alternans.

Conclusion

There are more similarities than differences between the predicate device and the Cambridge Heart HearTwave II Cardiac Diagnostic System. Both the predicate devices use the Analytic Spectral Method of Alternans Processing. When used in accordance with the directions for use, by qualified personnel, the Cambridge Heart HeartWave II Cardiac Diagnostic System is safe and effective, as indicated, for its intended use.

{3}------------------------------------------------

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

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

2005 APR 7

Cambridge Heart, Inc. c/o Mr. John Greenbaum 20310 SW 48th Street Ft. Lauderdale, Florida 33332

K050225 Re:

K050223
Trade Name: HearTwave II Cardiac Diagnostic System Regulation Number: 21 CFR 870.1425 Regulation Name: Programmable Diagnostic Computer Regulatory Class: Class II (two) Product Code: 74 DQK Dated: March 11, 2005 Received: March 15, 2005

Dear Mr. Greenbaum:

We have reviewed your Section 510(k) premarket notification of intent to market the device We have reviewed your Section 510(x) premaint is substantially equivalent (for the indications
referenced above and have determined the devices marketed in interstate referenced above and have determined the acvee is sedicate devices marketed in interstate for use stated in the enclosure to tegally interest date of the Medical Device Amendments, or to
commerce prior to May 28, 1976, the enatures with the provision of the Federa commerce prior to May 28, 1976, the eliaculance with the provisions of the Federal Food, Drug, devices that have been reclassined in accordance warane approval application (PMA).
and Cosmetic Act (Act) that do not require approval approval applisions of the Act. The and Cosmetic Act (Act) that do not require approval or the general controls of the Act. The Act. The You may, therefore, market the device, subject to the gents for annual registration, listing of
general controls provisions of the Act include requires misbranding and general controls provisions of the Act mender requirements of a seainst misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it If your device to such additional controls. Existing major regulations affecting your device can
may be subject to such additional controls. Exist. 21 - 80 - In addition F may be subject to such additions. Laisting may regalato 898 In addion, FDA may
be found in the Code of Federal Regulations, Title 21, Parts 800 to 898 In addion, FDA m be found in the Code of Federal Regalations, The Federal Register.

{4}------------------------------------------------

Page 2 -- Mr. John Greenbaum

Please be advised that FDA's issuance of a substantial equivalence determination does not mean 1 Toast be advised that 1 Dris assumes over device complies with other requirements of the Act that I Dri has made a actuations administered by other Federal agencies. You must or any I cochar statutes and regalazents and united to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set CFR Part 807); adoning (21 CFR Part 820); and if applicable, the electronic forth in the quality bybeline (Sections 531-542 of the Act); 21 CFR 1000-1050. product lauation control provisions (overing your device as described in your Section 510(k) This letter wif anow you to ogen finding of substantial equivalence of your device to a legally prematication: The PDF intentigation 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 If you desire specific acrice ior Jour as 1) 276-0120. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97) you may obtain. Ivilsoranding of reference to premeesponsibilities under the Act may be obtained from the Oinci general informational and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely yours,

B. Summerfor

Bram D. Zuckerman, M.D. Director Division of Cardiovascular Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

{5}------------------------------------------------

Page 1 of 1

510(k) Number(if known): K050225

Device Name: HearTwave II Cardiac Diagnostic System

Indications For Use:

The predictive value of T-wave Alternans for cardiac events has not been established in patients with active, untreated ischemia.

Prescription Use_X_ (Per 21 CRF 801.109) Over-The-Counter Use

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Kllummer

(Division Sign-Off)
Division of Cardiovascular Devices
510(k) Number K050225

Regulation Number and Section

§ 870.1425 Programmable diagnostic computer.

(a)
Identification. A programmable diagnostic computer is a device that can be programmed to compute various physiologic or blood flow parameters based on the output from one or more electrodes, transducers, or measuring devices; this device includes any associated commercially supplied programs.(b)
Classification. Class II (performance standards).