The CardioTag device is a tool that can be used to record, display and transfer vibrational waveforms produced by the heart contractions and transmitted to the chest as well as single-channel electrocardiogram (ECG) rhythms and heart rate. It also measures pulse waveform and pulse rate by photoplethysmograph (PPG). The CardioTag may be used as a tool to measure the timing of the aortic valve opening and closing in the cardiac cycle. The CardioTag is intended for spot-checking of adult patients in clinics or at home under the care of a physician. The data from the CardioTag is intended for use by healthcare professionals as an aid to diagnosis and treatment.
Device Story
CardioTag is a rechargeable wearable device for spot-check cardiac monitoring. User places device on sternum for 2-minute recording session. Device inputs include single-lead ECG (electrodes), PPG (optical sensors), and SCG (accelerometer) to capture heart contraction vibrations. Data transfers to cloud-based backend for processing and calculation of heart/pulse rates. System generates downloadable PDF report for clinician review. Clinician uses output to aid diagnosis, treatment, and timing of aortic valve opening/closing. Device intended for use in clinics or home settings under physician supervision.
Clinical Evidence
Clinical study conducted in the US with diverse demographic representation. Primary endpoints met; results demonstrated acceptable performance and high accuracy compared to commercially available devices. Biocompatibility (ISO 10993-1), electrical safety, and EMC testing also performed.
Technological Characteristics
Reusable, battery-powered wearable. Sensors: electrodes (ECG), optical sensor arrays (PPG), accelerometer (SCG). Connectivity: cloud-based backend for data storage/processing. Biocompatibility: ISO 10993-1 (cytotoxicity, sensitization, irritation). Safety: compliant with electrical safety, EMC, and wireless coexistence standards. Form factor: chest-worn, adhesive-applied.
Indications for Use
Indicated for spot-checking adult patients in clinical or home settings under physician care to record/display/transfer heart contraction vibrational waveforms (SCG), single-channel ECG, heart rate, and PPG-derived pulse waveform/rate. Used as an aid to diagnosis and treatment by healthcare professionals.
Regulatory Classification
Identification
A ballistocardiograph is a device, including a supporting structure on which the patient is placed, that moves in response to blood ejection from the heart. The device often provides a visual display.
Predicate Devices
HeartForce Medical, dBG Digital Ballistocardiograph (K081603)
{0}
FDA U.S. FOOD & DRUG ADMINISTRATION
July 22, 2025
Cardiosense, Inc.
Arezou Azar
VP, Compliance
400 N Aberdeen St.
Suite 900
Chicago, Illinois 60642
Re: K243566
Trade/Device Name: CardioTag
Regulation Number: 21 CFR 870.2320
Regulation Name: Ballistocardiograph
Regulatory Class: Class II
Product Code: DXR, DRG, DPS, MWI
Dated: June 17, 2025
Received: June 17, 2025
Dear Arezou Azar:
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"
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
{1}
K243566 - Arezou Azar
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.
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).
{2}
K243566 - Arezou Azar
Page 3
Sincerely,
Jennifer W. Shih -S
Jennifer Kozen
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
{3}
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.
Submission Number (if known)
K243566
Device Name
CardioTag™
Indications for Use (Describe)
The CardioTag device is a tool that can be used to record, display and transfer vibrational waveforms produced by the heart contractions and transmitted to the chest as well as single-channel electrocardiogram (ECG) rhythms and heart rate. It also measures pulse waveform and pulse rate by photoplethysmograph (PPG). The CardioTag may be used as a tool to measure the timing of the aortic valve opening and closing in the cardiac cycle. The CardioTag is intended for spot-checking of adult patients in clinics or at home under the care of a physician. The data from the CardioTag is intended for use by healthcare professionals as an aid to diagnosis and treatment.
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."
{4}
CARDIOSENSE
K243566
Page 1 of 4
# 510(k) Summary
## I. SUBMITTER
Cardiosense, Inc.
400 N Aberdeen St., Suite 900
Chicago, IL 60642
Contact Person: Arezou Azar, Ph.D.
VP Compliance (Regulatory, Quality, Clinical) and Program Management
email: arezou@cardiosense.com
Phone: (650) 804-0285
Date Prepared: November 15, 2024
## II. DEVICE
Name of Device: CardioTag™
Common or Usual Name: Ballistocardiograph or seismocardiogram (SCG)
Classification Name: Ballistocardiograph (21 CFR 870.2320)
Regulatory Class: II
Product Code: DXR (primary); DRG, DPS, MWI
## III. PREDICATE DEVICE
Primary: HeartForce Medical, dBG Digital Ballistocardiograph, K081603
Secondary: Meridian, McPulse Photoelectric Plethysmograph, K023238
## IV. DEVICE DESCRIPTION
The CardioTag device consists of a rechargeable wearable that is responsible for collecting raw cardiac signals from a single patient, and produces a spot-check report of a patient's electrocardiogram (ECG), photoplethysmogram (PPG), and seismocardiogram (SCG) signals and heart rate. To generate the report, the user places the wearable on the sternum and starts a 2 minute recording session for waveform output and heart rate /pulse rate calculation. The wearable contains electrodes to measure single-lead ECG, light sources and optical sensor arrays to measure PPG, and an accelerometer to measure vibrational waveforms from the heart's contractions transferred to the chest wall (SCG). Sensor data is then transferred for storage and processing (e.g. to a cloud-based backend). The backend uses the recording to calculate heart rate and pulse rate and then visualizes the waveforms and heart rate in the format of a downloadable PDF report for the clinician. The SCG signal is intended to be used for manual interpretation by the clinician in conjunction with other information from the device. The device
{5}
CARDIOSENSE
K243566
Page 2 of 4
may be used as a tool to measure the timing of the aortic valve opening and closing in the cardiac cycle.
## V. INDICATIONS FOR USE
The CardioTag device is a tool that can be used to record, display and transfer vibrational waveforms produced by the heart contractions and transmitted to the chest as well as single-channel electrocardiogram (ECG) rhythms and heart rate. It also measures pulse waveform and pulse rate by photoplethysmograph (PPG). The CardioTag may be used as a tool to measure the timing of the aortic valve opening and closing in the cardiac cycle. The CardioTag is intended for spot-checking of adult patients in clinics or at home under the care of a physician. The data from the CardioTag is intended for use by healthcare professionals as an aid to diagnosis and treatment.
## VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE
Both the subject device and predicates have the same intended use.
The subject device combines the outputs of the primary and secondary predicate devices as an all-in-one solution. The subject and primary predicate are aligned in that they are both reusable, battery powered devices placed on the chest via adhesives, perform spot checks (i.e. non-continuous measurements), and output ECG and vibrational waveforms in reports. The subject device and secondary predicate are similar in that they are battery powered, reusable devices that are used for spot-check measurements (i.e. non-continuous measurement), and both output PPG waveforms and use PPG as an input into heart rate calculations.
Minor technological differences have been addressed through risk management, bench-testing, clinical testing, and application of FDA-Recognized standards and, thus, do not raise new questions of safety and effectiveness.
## VII. PERFORMANCE DATA
The following performance data were provided in support of the substantial equivalence determination.
### Biocompatibility Testing
The biocompatibility evaluation for the CardioTag device was conducted in accordance with the FDA guidance document, Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process", September 2023, and International Standard ISO 10993-1 Biological Evaluation of Medical Devices - Part 1: Evaluation and Testing Within a Risk Management Process, as recognized by FDA.
Patient-contacting parts of the device were subjected to the following tests:
- Cytotoxicity
- Sensitization
- Irritation
{6}
CARDIOSENSE
K243566
Page 3 of 4
The CardioTag has Limited (<24 hrs) contact duration with (surface) intact skin.
## Electrical Safety and Electromagnetic Compatibility (EMC)
Electrical safety, EMC, and wireless coexistence testing were conducted on the CardioTag device. The device complies with the following standards:
## Basic Safety and Performance
- Basic safety and Essential Performance
- Defibrillation – Proof Applied Parts (Differential Mode)
- Proof Applied Parts (Common Mode)
## Electromagnetic Compatibility
Electrical safety and EMC testing was performed to applicable standards, including EMC/RF disturbances and immunity.
## Software Verification and Validation Testing
Software verification and validation testing were conducted and documentation was provided as recommended by FDA’s Guidance for Industry and FDA Staff, Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices, November 2021.
## Performance Testing
Bench-testing (non-clinical) was conducted for ECG, PPG, SCG functions to confirm that the following functions met specifications:
- ECG Validation
- PPG Validation
- SCG Validation
## Animal Studies
No animal studies were undertaken to support substantial equivalence.
## Clinical Studies
The CardioTag device has been clinically tested and validated in the US. Substantial equivalence was based in part on the clinical study. The subjects were recruited based on US demographics to present proper race and ethnicity to ensure diverse representation.
The primary endpoints for the CardioTag study were all met. The study results demonstrated that the CardioTag performs at an acceptable level when compared to commercially available devices with high accuracy.
{7}
CARDIOSENSE
K243566
Page 4 of 4
# VIII. CONCLUSIONS
The subject and predicate devices have the same Intended Use and similar technological characteristics. Bench-testing, biocompatibility, electrical safety and EMC, and clinical studies demonstrate that the differences in technological characteristics do not raise new questions of safety and effectiveness. As such, the CardioTag is substantially equivalent to the predicate devices.
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.