Stethophone Pro is an electronic stethoscope that enables detection, amplification, filtering, and transmission of auscultation sound data (heart and lungs), whereby a clinician at one location can listen to the auscultation sounds of a patient acquired on site or at a different location. Stethophone Pro is intended for use on adult patients. Stethophone Pro is not intended for self-diagnosis and not intended to be used as a sole means of diagnosis. Stethophone Pro can be used in clinical and nonclinical environments.

For Rx-only: Stethophone Pro is intended to provide decision support to clinicians in their evaluation of patients' heart sounds. The software analyzes heart sounds and phonocardiograms and can automatically detect murmurs that may be present, sound timing and character, including S1, S2, and the absence of a heart murmur. The interpretations of heart sounds offered by the software are not diagnoses and are meant only to provide decision support to the clinician, who may use the result in conjunction with their own evaluation and clinical judgment.

For OTC: When used without access to the automatic analysis feature or under supervision of healthcare professional, Stethophone Pro is also intended to be used by lay users.

Device Description

Stethophone Pro is an electronic stethoscope software application that operates on smartphones. Stethophone enables the capture and amplification of chest sounds for real-time or recorded listening. Cloud storage with sound record sending capabilities, filtering for selected frequency ranges, and visualization all assist with sound analysis.

Stethophone is designed to assist healthcare professionals in both hearing and visualizing heart and lung sounds during a physical examination of a patient and in storing recorded sounds in the cloud for later analysis. It also enables home users to record and send chest sounds to their physicians.

Stethophone can be used for the assessment of chest sounds of adult patients in clinical and non-clinical environments. Assessment should be performed by healthcare professionals, while sound capturing can be performed by both healthcare professionals and home users.

While all functions described above are available to both prescription and OTC users, the following analysis features and the associated report are accessible exclusively with a prescription: Stethophone Pro performs basic analysis of heart sounds, including detection of murmurs, identification of S1 and S2 heartbeats on the timeline, and calculation of timing intervals between them.

Key Product Features Available for both prescription and OTC users

Capturing chest sounds using the smartphone microphone:
- Real-time listening to chest sounds
- Recording of chest sounds
Sending examinations to specialists for assessment
Two modes of sound visualization: oscillogram and spectrogram
Selecting from three audio filters for listening:
- Bell Traditional filter used in stethoscopes for low frequency sounds
- Diaphragm Traditional filter used for higher frequency sounds of heart and lungs
- Starling Filter for listening to the full frequency of chest sounds

All of these features are present in both the primary predicate, Stethophone Pro (K240901), and the reference device, Stethophone (K231551), and are now available for OTC use.

Product Features For prescription users only

Detecting murmurs, timing for S1 and S2 sounds, and calculating heart rate

These features are derived from the Stethophone Pro (K240901, Rx-only).

Collectively, these features enable home users to acquire their own sounds, share them with healthcare professionals, and control their health, as well as allow healthcare professionals to examine and monitor patients on site and remotely, seek out second opinions from specialists, and use the device in a telemedicine context.

AI/ML Overview

Based on the provided FDA 510(k) clearance letter for Stethophone Pro (K252595), here's an analysis of the acceptance criteria and study information:

The document explicitly states that no new performance data was required for this submission. This is because the device is a modified version of previously cleared devices (Stethophone Pro K240901 and Stethophone K231551), and the modifications were solely to the indications for use, not to the underlying acoustics algorithms or automated sound analysis capabilities.

Therefore, the following information is not available in the provided document, as no new studies were conducted for this specific clearance (K252595):

A table of acceptance criteria and the reported device performance
Sample sizes used for the test set
Data provenance for the test set
Number of experts used to establish ground truth for the test set
Qualifications of experts
Adjudication method for the test set
Whether a multi-reader multi-case (MRMC) comparative effectiveness study was done
Effect size of human reader improvement with AI vs. without AI assistance
If a standalone performance (algorithm only without human-in-the-loop performance) was done
Type of ground truth used (expert consensus, pathology, outcomes data, etc.)
Sample size for the training set
How the ground truth for the training set was established

However, we can infer that acceptance criteria and performance data were established and met in the previous clearances (K240901 and K231551) for the functionalities that remain unchanged.

Summary of Device Performance and Acceptance Criteria (Based on Previous Clearances - Not explicitly detailed in this document):

The document states:

"The acoustics algorithms for sound filtering (that are used for both OTC and Rx parts of the software) capabilities remain entirely unchanged from those validated and cleared in both K240901 and K231551."
"Automated sound analysis capabilities (that are available for Rx use only) remain entirely unchanged from those validated and cleared in K240901."

This implies that for the features that do have performance claims (specifically, automated sound analysis for murmur detection and heart sound timing in the Rx-only version), acceptance criteria were met during the clearance of K240901. Similarly, for the basic functions of sound capture, amplification, filtering, and transmission, acceptance criteria were met during the clearance of K231551 and K240901.

To obtain the specific details regarding the acceptance criteria, study designs, sample sizes, and ground truth methodologies for these functionalities, one would need to refer to the original 510(k) submissions for K240901 and K231551. This current document (K252595) serves as a modification that leverages the previously established substantial equivalence and performance data.

Summary

FDA 510(k) Clearance Letter - Stethophone Pro

Page 1

September 12, 2025

Sparrow Acoustics Inc.
Nadia Ivanova
Chief Product Officer
2416 Natura Dr.
Lucasville, NS B4B 0X3
Canada

Re: K252595
Trade/Device Name: Stethophone Pro
Regulation Number: 21 CFR 870.1875
Regulation Name: Stethoscope
Regulatory Class: Class II
Product Code: DQD
Dated: August 11, 2025
Received: August 15, 2025

Dear Nadia Ivanova:

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.

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"

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K252595 - Nadia Ivanova Page 2

(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 (QS) 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 (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-reporting-combination-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-devices/device-advice-comprehensive-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-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

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K252595 - Nadia Ivanova Page 3

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/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-devices/device-advice-comprehensive-regulatory-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,

Stephen C. Browning -S

LCDR Stephen Browning
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

Page 4

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2023
See PRA Statement below.

510(k) Number (if known): K252595

Device Name: Stethophone Pro

Indications for Use (Describe)

For Rx-only: Stethophone Pro is intended to provide decision support to clinicians in their evaluation of patients' heart sounds. The software analyzes heart sounds and phonocardiograms and can automatically detect murmurs that may be present, sound timing and character, including S1, S2, and the absence of a heart murmur. The interpretations of heart sounds offered by the software are not diagnoses and are meant only to provide decision support to the clinician, who may use the result in conjunction with their own evaluation and clinical judgment.

For OTC: When used without access to the automatic analysis results or under supervision of healthcare professional, Stethophone Pro is also intended to be used by lay users.

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services
Food and Drug Administration
Office of Chief Information Officer
Paperwork Reduction Act (PRA) Staff
PRAStaff@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

FORM FDA 3881 (6/20) Page 1 of 1 PSC Publishing Services (301) 443-6740 EF

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510(k) SUMMARY

Page 1 of 4
Stethophone Pro – Special 510(k): Device Modification – K252595

1	Summary Date	September 10, 2025
2	Submitter	Sparrow Acoustics Inc.2416 Natura Dr.Lucasville, NSCanada, B4B 0X3Tel: +1 (902) 989-3908
3	Correspondent	Nadia Ivanova
4	Device Trade Name	Stethophone Pro
5	Device Common Name	Smartphone stethoscope
6	Classification	Electronic Stethoscope21 CFR 870.1875(b)Class IIProduct Code: DQDPanel: Cardiovascular

7. Intended Use / Indications for Use

For OTC: When used without access to the automatic analysis feature or under supervision of healthcare professional, Stethophone Pro is also intended to be used by lay users.

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Page 2 of 4
Stethophone Pro – Special 510(k): Device Modification – K252595

8. Device Description

Key Product Features Available for both prescription and OTC users

Capturing chest sounds using the smartphone microphone:
- Real-time listening to chest sounds
- Recording of chest sounds
Sending examinations to specialists for assessment
Two modes of sound visualization: oscillogram and spectrogram
Selecting from three audio filters for listening:
- Bell Traditional filter used in stethoscopes for low frequency sounds
- Diaphragm Traditional filter used for higher frequency sounds of heart and lungs
- Starling Filter for listening to the full frequency of chest sounds

All of these features are present in both the primary predicate, Stethophone Pro (K240901), and the reference device, Stethophone (K231551), and are now available for OTC use.

Product Features For prescription users only

Detecting murmurs, timing for S1 and S2 sounds, and calculating heart rate

These features are derived from the Stethophone Pro (K240901, Rx-only).

9. Predicate Devices

Stethophone Pro (primary)	Stethophone (reference)
510(k) Number: K240901¹Manufacturer: Sparrow Acoustics Inc.Product Code: DQDClassification: 870.1875	510(k) Number: K231551²Manufacturer: Sparrow Acoustics Inc.Product Code: DQDClassification: 870.1875

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Page 3 of 4
Stethophone Pro – Special 510(k): Device Modification – K252595

10. Comparison to Predicates

The comparison chart below provides evidence to facilitate the substantial equivalence determination between Stethophone to the predicate devices with respect to intended use, technological characteristics, and principles of operation:

Characteristic	Stethophone Pro version 3.6.0	Stethophone Pro versions 3.0.0 - 3.5.0	Stethophone version 2.x.x
Classification	Class II device	Class II device	Class II device
US FDA Regulation	21 CFR 870.1875(b)	21 CFR 870.1875(b)	21 CFR 870.1875(b)
Product code	DQD	DQD	DQD
Device	Stethoscope, Electronic	Stethoscope, Electronic	Stethoscope, Electronic
US FDA Clearance	Pending	K240901	K231551
Intended Use / Indications for Use	Stethophone Pro is an electronic stethoscope that enables detection, amplification, filtering, and transmission of auscultation sound data (heart and lungs), whereby a clinician at one location can listen to the auscultation sounds of a patient acquired on site or at a different location. Stethophone Pro is intended for use on adult patients. Stethophone Pro is not intended for self-diagnosis and not intended to be used as a sole means of diagnosis. Stethophone Pro can be used in clinical and nonclinical environments.For Rx-only: Stethophone Pro is intended to provide decision support to clinicians in their evaluation of patients' heart sounds. The software analyzes heart sounds and phonocardiograms and can automatically detect murmurs that may be present, sound timing and character, including S1, S2, and the absence of a heart murmur. The interpretations of heart sounds offered by the software are not diagnoses and are meant only to provide decision support to the clinician, who may use the result in conjunction with their own evaluation and clinical judgment.For OTC: When used without access to the automatic analysis feature or under supervision of healthcare professional, Stethophone Pro is also intended to be used by lay users.	Stethophone Pro is an electronic stethoscope that enables detection, amplification, filtering, and transmission of auscultation sound data (heart and lungs).Stethophone Pro is intended to provide decision support to clinicians in their evaluation of patients' heart sounds. The software analyzes heart sounds and phonocardiograms and can automatically detect murmurs that may be present, sound timing and character, including S1, S2, and the absence of a heart murmur.Stethophone Pro is not intended to be used as a sole means of diagnosis and is for use in environments where health care is provided by clinicians. The interpretations of heart sounds offered by the software are meant only to provide decision support to the clinician, who may use the result in conjunction with their own evaluation and clinical judgment. The interpretations are not diagnoses.Stethophone Pro is intended for use on adult patients.	Stethophone is an electronic stethoscope that enables detection, amplification, filtering, and transmission of auscultation sound data (heart and lungs), whereby a clinician at one location can listen to the auscultation sounds of a patient acquired on site or at a different location.Stethophone is intended for use on adult patients. Stethophone is intended to be used by professional or lay users in a clinical or nonclinical environment. Stethophone is not intended for self-diagnosis.
Prescription/ OTC	Prescription and OTC	Prescription	Prescription and OTC
Population Type	Adults	Adults	Adults
Device Type	Standalone software for smartphone	Standalone software for smartphone	Standalone software for smartphone
Dedicated Device vs. Smartphone	Operates on smartphone using its hardware and operating system	Operates on smartphone using its hardware and operating system	Operates on smartphone using its hardware and operating system

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Page 4 of 4
Stethophone Pro – Special 510(k): Device Modification – K252595

Characteristic	Stethophone Pro version 3.6.0	Stethophone Pro versions 3.0.0 - 3.5.0	Stethophone version 2.x.x
iPhone model Compatibility	XS, XS Max, XR, SE 2nd gen, 11, 11 Pro, 11 Pro Max, 12, 12 Pro, 12 Mini, 12 Pro Max, 13, 13 mini, 13 Pro, 13 Pro Max, SE 3rd gen, 14, 14 Plus, 14 Pro, 14 Pro Max, 15, 15 Plus, 15 Pro, 15 Pro Max, 16, 16 Plus, 16 Pro, 16 Pro Max, 16e	XS, XS Max, XR, SE 2nd gen, 11, 11 Pro, 11 Pro Max, 12, 12 Pro, 12 Mini, 12 Pro Max, 13, 13 mini, 13 Pro, 13 Pro Max, SE 3rd gen, 14, 14 Plus, 14 Pro, 14 Pro Max, 15, 15 Plus, 15 Pro, 15 Pro Max, 16, 16 Plus, 16 Pro, 16 Pro Max, 16e	XS, XS Max, XR, SE 2nd gen, 11, 11 Pro, 11 Pro Max, 12, 12 Pro, 12 Mini, 12 Pro Max, 13, 13 mini, 13 Pro, 13 Pro Max, SE 3rd gen, 14, 14 Plus, 14 Pro, 14 Pro Max, 15, 15 Plus, 15 Pro, 15 Pro Max, 16, 16 Plus, 16 Pro, 16 Pro Max, 16e
Software Platform	iOS	iOS	iOS
Sound Type	Heart, lungs	Heart, lungs	Heart, lungs
Sound Processing	Yes	Yes	Yes
Ability to Visualize Sound	Spectrogram, oscillogram	Spectrogram, oscillogram	Spectrogram, oscillogram
Murmur detection	Yes	Yes	No
Heart sound timing	Yes	Yes	No
Signal quality assessment	Yes	Yes	No

11. Performance Data

The acoustics algorithms for sound filtering (that are used for both OTC and Rx parts of the software) capabilities remain entirely unchanged from those validated and cleared in both K240901 and K231551. Automated sound analysis capabilities (that are available for Rx use only) remain entirely unchanged from those validated and cleared in K240901. Therefore, no new performance data is required.

12. Biocompatibility Testing

Not Applicable (Standalone Software)

13. Sterilization & Shelf-life Testing

Not Applicable (Standalone Software)

14. Electrical safety and electromagnetic compatibility (EMC)

Not Applicable (Standalone Software)

15. Statement of Substantial Equivalence

Stethophone Pro is a modified version of the previously cleared primary predicate Stethophone Pro K240901 and reference Stethophone K231551. All technological characteristics are the same, including the entire acoustics features and automated analysis. This submission was solely intended to address a modification to the indications for use.

Stethophone Pro and the predicates have the same intended use and similar indications, technological characteristics and principles of operation, and had no modifications to affect performance. The minor differences in indications for use do not present different questions of safety or effectiveness than the predicate devices.

This summary of 510(k) safety and effectiveness information is submitted in accordance with the requirements of 21 CFR §807.92.

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.