The product will acquire and record the acoustic signals of the heart and analyze these signals. The analysis procedure will identify specific heart sounds that may be present. Identified sounds include S1, S2, and suspected systolic murmurs.

The device is indicated for use in the clinical setting, by a physician or by trained personnel who are acting on the orders of a licensed physician. It in not intended as a sole means of diagnosis.

The interpretations of heart sounds offered by the Heart STG System are only significant when used in conjunction with physician over-read as well as consideration of all relevant patient data.

Device Description

The Heart STG is software intended to provide support to medical personnel in the evaluation of heart sounds. The software records and analyzes an acoustic signal of the heart and aids the healthcare provider by marking S1, S2, and suspected systolic murmurs on the waveform.

As a complete system the Heart STG system consists of an electronic stethoscope and software running on a computer with Windows operating system. The user must provide a compatible electronic stethoscope and a computer.

AI/ML Overview

The Stethographics Heart STG System is designed to provide support to physicians in evaluating heart sounds, specifically identifying S1, S2, and suspected systolic murmurs.

Here's a breakdown of its acceptance criteria and the study proving it meets them:

1. Table of Acceptance Criteria (Implicit) and Reported Device Performance

Performance Metric	Acceptance Criteria (Stated Goal: Comparability to Expert Cardiologists)	Reported Device Performance (STG Data Set)	Reported Device Performance (Proctor Harvey Data Set)
Overall Percent Agreement with Experts	Comparable to inter-cardiologist agreement	83%	82%
Agreement with Murmur-Positive (Recall)	Comparable to inter-cardiologist agreement	70%	91%
Agreement with Murmur-Negative (Specificity)	Comparable to inter-cardiologist agreement	93%	62%
Heart Rate (HR) Correlation with Experts	High correlation (e.g., >0.90)	0.96	0.91

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

The device was evaluated using two test sets:

STG Data Set:
- Sample Size: 91 sounds from 91 patients.
- Data Provenance: Prospective collection. The sounds were obtained from patients scheduled for echocardiography assessment. Specific country of origin is not explicitly stated, but the company is located in Boston, MA, suggesting a US origin for this data.
Proctor Harvey Data Set:
- Sample Size: 363 sounds from 232 patients (63 from children, 300 from adults).
- Data Provenance: This is a retrospective, pre-existing dataset. It's described as "provided in the Clinical Auscultation of the Cardiovascular System, by Proctor Harvey and David C. Canfield," which is considered a "gold standard for teaching and covers a broad range of heart disorders." Its origin is likely academic/educational.

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

Number of Experts: Three experienced cardiologists.
Qualifications: "Experienced cardiologists." No specific years of experience are provided.

4. Adjudication Method for the Test Set

Adjudication Method: 2+1 (two out of three cardiologists agreeing on the presence or absence of a murmur).
- "All sounds were graded by three experienced cardiologists. Ground truth was considered to be positive when 2 out of 3 cardiologists agreed on the presence of murmur." (This implies a similar rule for negative cases, though not explicitly stated for negative cases, the performance tables show agreement with 2/3 cardiologists positive and negative).

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

No, an MRMC comparative effectiveness study was not done. The study design focuses on comparing the device's performance against expert consensus ground truth. While inter-cardiologist agreement is reported, there's no comparison of human readers with and without AI assistance to determine an effect size for improvement.

6. Standalone (Algorithm Only) Performance Study

Yes, a standalone performance study was done. The reported "Heart STG +" and "Heart STG -" values represent the algorithm's performance in identifying murmurs without human intervention, compared against the adjudicated ground truth.

7. Type of Ground Truth Used

Type of Ground Truth: Expert consensus (three experienced cardiologists, with a 2-out-of-3 agreement rule).

8. Sample Size for the Training Set

Not explicitly stated. The document describes the "test sets" (STG data set and Proctor Harvey data set) but does not provide details on the training data used for the algorithm.

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

Not explicitly stated for the training set. Given the approach for the test sets, it is highly probable that the training data ground truth was also established by expert cardiologists. However, the document focuses exclusively on the ground truth establishment for the test (evaluation) datasets.

Summary

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DEC 2 3 2005

K052283

115

Stethographics, Heart STG System 510(k) Summary

Company:

Stethographics, Inc 1153 Centre Street Boston, MA

Owner:

Raymond Murphy 1153 Centre St. Boston, MA Phone: (617) 983-7259 Fax: 617-522-4156

Contact:

Rozanne Paciej Stethographics, Inc 1153 Centre Street Boston, MA

Date Prepared:

August 17, 2005

Name of Device:

Stethographics Heart STG System

Common Name of Device:

Electronic Stethoscope

Classification Name:

Heart STG System 21 CFR 870.1870

Predicate Devices:

The Stethographics Heart STG System is substantially equivalent to the Zargis' Acoustic Cardioscan (#K031517).

Stethographics 510(k)

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Intended Use:

The Stethographics Heart STG is software intended to provide support to the physician in the evaluation of heart sounds in patients.

The product will acquire and record the acoustic signals of the heart and analyze these The product will acquire and reversity identify specific heart sounds that may be present. Identified sounds include S1, S2, and suspected systolic murmurs.

The device is indicated for use in the clinical setting, by a physician or by trained The device is indicated for use in the entired physician. It in not intended as a sole means of diagnosis.

The interpretations of heart sounds offered by the Heart STG System are only significant The microletonio of near with physician over-read as well as consideration of all relevant patient data.

Device Description:

The Heart STG is software intended to provide support to medical personnel in the The Freart STO is software mension vare records and analyzes an acoustic signal of the e valuation of near bounds - aids the healthcare provider by marking SI, S2, and suspected systolic murmurs on the waveform.

As a complete system the Heart STG system consists of an electronic stethoscope and As a complete system the rical by on a computer with Windows operating system. The user must provide a compatible electronic stethoscope and a computer.

Technological Characteristics:

The technological characteristics of the new device are compatible to those of the predicate devices.

Performance Data:

Both bench testing and clinical testing were performed to ensure that the device performs Doth ochen testing and chilied tooling in this pre-market notification includes descriptive as intended. The intended supplied in the echnological characteristics.

This information is provided pursuant to the requirements of the Safe Medical Devices Act of 1990 (SMDA).

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Device Specification
Recording frequency range	20Hz to 2000Hz
Sampling frequency	8,000 Hz
Data recording	Standard .wav (PCM) files at resolution of 16 Bit, Mono.
Recording time	20 seconds
Acoustic sensor	Electronic stethoscope. Compatible models include AndromediStethos, Cardionics e-Scope, 3M E-4000.
Number of sensors	1

----------------------------------------------------------------------------------------------------------------Device Snecification

Heart Sound Analysis STG Performance Data

In order to evaluate the Heart STG with both common heart disorders and more rare disorders, two different sets of cardiac sounds were utilized. The first set of cardiac fare disorders, two allerentise of Heart STG to record 91 patients that were scheduled Sounds were obtained of assessment (referred to as the STG data set). The second set was for conocurdio graphy abbeart sounds provided in the Clinical Auscultation of the Cardiovascular System, by Proctor Harvey and David C. Canfield (referred to as the Cardiovasoular Systems of Proctor Harvey course is considered the gold standard for I roctor frai vey tata bething and covers a broad range of heart disorders (363 sounds total), both common and rare. All sounds were graded by three experienced cardiologists. total), both common and fare. In be ositive when 2 out of 3 cardiologists agreed on the presence of murmur.

The STG data set included 91 sounds from 91 patients that were scheduled for th echocardiography assessment. Average age was 61±17 years (range 23 to 94). The cender distribution in this population was 44% male and 56% female. The patients were gender distribution in this peparates recording. The STG recorded 20 second sounds asked to nota then orean ouring stres STG performance to that of the cardiologists. The '+' indicates murmur-positive sounds and '-' indicates murmur-negative sounds.

		Table 1. STG compared to 2 out of 3 cardiologists. STG Data Set.
		------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Number of sounds 91	2 out of 3 cardiologists +	2 out of 3 cardiologists -
Heart STG +	23	4
Heart STG -	10	54

The corresponding overall percent agreement = 100%(23 + 54)/91 = 83% The contesponding overall percent adjoonists -positive = 100%(23)(23+10) = 70% Agreement of the STG with 2/3 cardiologists-negative = 100%*(54)/(54+4) = 93%

The Proctor Harvey data set included 363 sounds from 232 patients. Sixty-three sounds were recorded from children, 300 from adults. The Proctor Harvey data set is sounds were recorded from only of common and less common heart pathologies and, represemative of grout namber of be algorithm's performance in both common and less ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Stethographics 510(k)

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-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------common heart conditions. Table 2 compares STG performance to that of the cardiologists.

Table 2. STG compared to 2 out of 3 cardiologists. Proctor Harvey Data Set.

Number of sounds 363	2 out of 3 cardiologists+	2 out of 3 cardiologists-
Heart STG +	227	43
Heart STG -	23	70

The corresponding overall percent agreement = 100%(227 + 70)/363 = 82% The concesponaing & verair p 2/3 cardiologists-positive = 100%(227)(227+23) = 91% Agreement of the STG with 2/3 cardiologists-negative = 100%*(70)/(70+43) = 62%

The agreement between cardiologists was also calculated, Tables 3 and 4, columns 3 to 8.

Table 3. Agreement between cardiologists. STG Data Set.

	STGcompared to2 out of 3cardiologists	Cardiologist1 withcardiologist2 as a goldstandard	Cardiologist1 withcardiologist3 as a goldstandard	Cardiologist2 withcardiologist1 as a goldstandard	Cardiologist2 withcardiologist3 as a goldstandard	Cardiologist3 withcardiologist1 as a goldstandard	Cardiologist3 withcardiologist2 as a goldstandard
Agreementwithmurmur-positive	70	91	100	72	93	67	79
Agreementwithmurmur-negative	93	79	77	94	89	100	96

Table 4. Agreement between cardiologists. Proctor Harvey Data Set.

	STGcompared to2 out of 3cardiologists	Cardiologist1 withcardiologist2 as a goldstandard	Cardiologist1 withcardiologist3 as a goldstandard	Cardiologist2 withcardiologist1 as a goldstandard	Cardiologist2 withcardiologist3 as a goldstandard	Cardiologist3 withcardiologist1 as a goldstandard	Cardiologist3 withcardiologist2 as a goldstandard
Agreementwithmurmur-positive	91	97	97	83	94	82	93
Agreementwith	62	61	60	91	86	91	88

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	=469==========================================================================================================================================================================

murmur-
negative

Thus, the STG agreement with 2/3 cardiologists was found to be comparable to that measured among experienced cardiologists.

Heart Rate (HR) was validated by comparing the HR calculated by the STG to that Treat Rale (TIT) was vanuated by contpassion. The correlations between the Heart STG canculated by JN Entimall: 21.000 tlosscope for the STG data set and Proctor Harvey data set are 0.96 and 0.91, respectively.

41,30200 p 5 / 5

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/6/Picture/2 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo features a stylized eagle head with three lines forming the head and neck. The words "DEPARTMENT OF HEALTH AND HUMAN SERVICES. USA" are arranged in a circular pattern around the eagle head.

DEC 2 3 2005

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Stethographics, Inc. c/o Ms. Rozanne Paciej Director, Regulatory Affairs Quality Assurance 1153 Centre Street Boston, MA 02130

Re: K052283

Trade Name: Stethographics Heart STG System Regulation Number: 21 CFR 870.1875 Regulation Name: Stethoscope Regulatory Class: Class II (two) Product Code: DQD Dated: November 14, 2005 Received: November 22, 2005

Dear Ms. Paciej:

We have reviewed your Section 510(k) premarket notification of intent to market the device We have reviewed your Section 510(x) prematics is substantially equivalent (for the indications referenced above and have determined the actived predicate devices marketed in interstate for use stated in the encrosule) to regally manced promoted in vice Amendments, or to
commerce prior to May 28, 1976, the enactment date of the Federal Food. Drug commerce prior to May 28, 1970, the chacance with the provisions of the Federal Food, Drug, devices that have been reculted in accordance while approval application (PMA).
and Cosmetic Act (Act) that do not require approval of a providions of the Act. The and Cosment Act (Act) that do not require approvate of the general controls of the Act. The You may, therefore, market the device, subject to tits gonto for annual registration, listing of the and general controls provisions of the Free merals required.
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 If your device is classified (SCC above) the entile is a control stars and control device can
may be subject to such additional controls. Existing major regulations EDA mov may be subject to such additional controllar antitudes of the 21, Parts 800 to 898. In addition, FDA may be found in the Code of Poderal Regaring your device in the Federal Register.

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Page 2 – Ms. Rozanne Paciej

Please be advised that FDA's issuance of a substantial equivalence determination does not mean Please be advised that FDA s issualice of a subscription with other requirements of the Act
that FDA has made a determination that your device complies . You must that FDA has made a decidination that your de received by other Federal agencies. You musti of any Federal statutes and regulations daminities, but not limited to: registration and listing (21)
comply with all the Act's requirements, including, but not limited to: r comply with all the Act s requirements, morams, connective requirements as set CFR Part 807); labeling (21 CFR Part 807); good if applicable, the electronic
forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electroni form in the quality systems (QD) regulation (Sections 531-542 of the Act); 21 CFR 1000-1050.
product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1 product radiation control provisions (Decions of the as described in your Section 5 (0(k)
This letter will allow you to begin marketing your device as described in your high I his letter will anow you to begin manceing your and equivalence of your device to a legally premarket notification. The PDA multing of substantial equal and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Patt 801), please if you desire specific advice for your ac not one one one not the regulation entitled. comact the Office of Complanes at (210) = 15 = 16 = 16 = 1 = 1 = 1 = 1 = 1 = 1 = 5 = = $ Small Misoraliung by reference to promantovitibilities under the Act from the Division of Small other general information on your responsibilities and its toll-free number (800) 638-204 or btrail Manufacturers, International and October http://www.fda.gov/cdrl/industry/support/index.html.

Sincerely yours,

A. Ui Feinter for
Bram D. Zuckerman, M.D.

Director Division of Cardiovascular Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): _ KOS 2283

K052283

Device Name: Stethographics Heart STG System

Indications for Use:

The Stethographics Heart STG System, is an electronic auscultatory device, intended to provide support to the physician in the evaluation of heart sounds in patients.

The device is indicated for use in the clinical setting, by a physician or by trained personnel who are acting on the orders of a licensed physician. It in not intended as a sole means of diagnosis.

The interpretations of heart sounds offered by the Heart STG System are only significant when used in conjunction with physician over-read as well as consideration of all relevant patient data.

Prescription Use XXX (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 OF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

A.M. Mcclellan for Brian D. Zuckerman, (MD)
(Division Sign-Off)

Division of Cardiovascular Devices

510(k) Number

Page 1 of 1

Regulation Number and Section

§ 870.1875 Stethoscope.

(a)
Manual stethoscope —(1)Identification. A manual stethoscope is a mechanical device used to project the sounds associated with the heart, arteries, and veins and other internal organs.(2)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.(b)
Electronic stethoscope —(1)Identification. An electronic stethoscope is an electrically amplified device used to project the sounds associated with the heart, arteries, and veins and other internal organs.(2)
Classification. Class II (special controls). The device, when it is a lung sound monitor, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.