(227 days)
Not Found
No.
The document does not mention AI, DNN, or ML, and the device description outlines a hardware-based system generating electromagnetic fields with preset frequencies and harmonics, without any indication of adaptive learning or AI model integration.
Yes
The device is described as a "medical device" and its intended use is to "temporarily increase blood circulation" and "stimulate healthy muscles to improve and facilitate muscle performance," which are therapeutic outcomes.
No
The device's intended use and function are solely for therapeutic purposes (increasing blood circulation, stimulating muscles), not for diagnosing conditions.
No
The device is not a software-only medical device because the description explicitly states it generates pulsed, bipolar, and variable electromagnetic fields using a "hardware component" and that it involves "generating a pulsed magnetic field." It also mentions "Performance testing, electromagnetic compatibility and safety testing were conducted in accordance with several standards, including EN 60601-1, EN 60601-1-2" which are standards for electrical medical equipment, not typically for pure software.
No.
The device description and intended use indicate it is an external physical therapy device using magnetic fields to stimulate muscles and improve blood circulation, not to analyze biological samples for diagnostic purposes.
N/A
Intended Use / Indications for Use
The indications for the Limfa Therapy System are to temporarily increase blood circulation in healthy leg muscles and to stimulate healthy muscles in order to improve and facilitate muscle performance.
Product codes
NGX
Device Description
The Limfa® Therapy System is a medical device, intended for stimulation with extremely low frequencies (ELF), pulsed, and low frequency (ELF 3-300 Hz) magnetic fields, which generates pulsed, bipolar and variable electromagnetic fields, at very low and variable intensity and frequency using complex waveforms (sinusoidal, triangular and rectangular), thus obtaining multiple signals within a frequency spectrum composed of base waves from 2 to 80 Hz plus the harmonics that are produced by the hardware component.
The manufacturer presets base wave frequencies and the harmonics are generated by the DM hardware. The therapy is based on the generation of a pulsed magnetic field with a very low and variable frequency and variable intensity.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Not Found
Anatomical Site
healthy leg muscles (specifically, skeletal muscles)
Indicated Patient Age Range
Not Found
Intended User / Care Setting
Hospitals, physician offices and home
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
Not Found
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
The electromagnetic compatibility and safety testing and other performance testing were conducted in accordance to the following standards:
- EN 60601-1: 2006 / A11: 2011 / A1: 2013 Medical electrical equipment. Part 1: General requirements relating to basic safety and essential performance
- EN 60601-1-2: 2015/A1: 2021; IEC 60601-1-2: 2014/A1: 2020 – Medical electrical equipment – Part 1: General requirements for safety and general requirements – Collateral standard: electromagnetic compatibility - Requirements and tests
- EN 62304: 2006 - Software for medical devices - Processes related to the software life cycle
- EN 62366: 2008 - Medical devices - Application of the engineering of the utilization characteristics to medical devices
- EN 62353: 2015 - Electro-medical equipment - Periodic checks and tests to be carried out after repairs to electro- medical equipment
- EN ISO 14971: 2019—Medical devices. Application of risk management to medical devices
- EN SIO 15223-1: 2021 – Symbols to be used in medical device labels, labeling, and information to be provided. Part 1: General requirements
- IEC TR 60601-4-2: Medical electrical equipment- Part 4-2: Guidance and interpretation – Electromagnetic immunity: performance of medical electrical equipment and medical electrical systems
In all instances the Limfa® Therapy System functioned as intended and the results observed were as expected.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Not Found
Predicate Device(s)
Reference Device(s)
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc)
Not Found
§ 890.5850 Powered muscle stimulator.
(a)
Identification. A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.(b)
Classification. Class II (performance standards).
FDA 510(k) Clearance Letter - Limfa Therapy System
Page 1
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
Doc ID # 04017.07.05
May 15, 2025
EYWA srl
℅ Thomas Lawson
Regulatory Affairs for EYWA srl
EYWA srl America
1224 Navellier Street
El Cerrito, California 94530
Re: K243165
Trade/Device Name: Limfa Therapy System (Limfa Therapy)
Regulatory Class: Class II
Product Code: NGX
Dated: September 26, 2024
Received: September 30, 2024
Dear Thomas Lawson:
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" (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).
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K243165 - Thomas Lawson Page 2
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).
Sincerely,
Tushar Bansal -S
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K243165 - Thomas Lawson Page 3
for Heather Dean, PhD
Assistant Director, Acute Injury Devices Team
DHT5B: Division of Neuromodulation and
Physical Medicine Devices
OHT5: Office of Neurological and
Physical Medicine 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: 07/31/2026
See PRA Statement below.
Submission Number (if known)
K243165
Device Name
Limfa Therapy System (Limfa Therapy)
Indications for Use (Describe)
The indications for the Limfa Therapy System are to temporarily increase blood circulation in healthy leg muscles and to stimulate healthy muscles in order to improve and facilitate muscle performance.
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
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"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."
Page 5
K243165 510(k) SUMMARY
General Information
| Submitter | Eywa S.r.l. |
|---|---|
| Address | Eywa S.r.l. |
| Via Pietrarubbia, 25/E | |
| Rimini 47922 | |
| Italy | |
| 510(k) Number | K243165 |
| Correspondence Person | Thomas Lawson, PhD |
| Contact Information | Email: drthomlawson@gmail.com |
| Phone: 510-206-1794 | |
| Date Prepared | 14 May 2025 |
Proposed Device
| Trade Name | Limfa® Therapy System |
|---|---|
| Common Name | Limfa® System |
| Regulation Number and Regulation Name | 21 CFR§890.5850. Powered Muscle Stimulator |
| Product Code | NGX |
| Regulatory Class | II |
Predicate Device #1
| Trade Name | Bemer Classic Set |
|---|---|
| Common Name | Bemer Classic |
| Premarket Notification | K151834 |
| Regulation Number and Classification Name | 21 CFR§890.5850, Powered Muscle Stimulator |
| Product Code | NGX |
| Regulatory Class | II |
Page 6
Predicate Device #2
| Trade Name | Bemer Classic Set |
|---|---|
| Common Name | Bemer Classic |
| Premarket Notification | K210174 |
| Regulation Number and Regulation Name | 21 CFR§890.5850. Powered Muscle Stimulator |
| Product Code | NGX |
| Regulatory Class | II |
Device Description
The Limfa® Therapy System is a medical device, intended for stimulation with extremely low frequencies (ELF), pulsed, and low frequency (ELF 3-300 Hz) magnetic fields, which generates pulsed, bipolar and variable electromagnetic fields, at very low and variable intensity and frequency using complex waveforms (sinusoidal, triangular and rectangular), thus obtaining multiple signals within a frequency spectrum composed of base waves from 2 to 80 Hz plus the harmonics that are produced by the hardware component.
The manufacturer presets base wave frequencies and the harmonics are generated by the DM hardware. The therapy is based on the generation of a pulsed magnetic field with a very low and variable frequency and variable intensity.
Indications for Use
The indications for use of the Limfa® Therapy System are:
- To temporarily increase local blood circulation in healthy leg muscles;
- To stimulate healthy muscles in order to improve and facilitate muscle performance;
The Limfa® Therapy System has the exact same intended use and indications for use
Page 7
statements as the BEMER Classic Set device.
Comparison of Technological Characteristics with the Predicate Devices
The Limfa® Therapy System is equivalent to two predicate devices in terms of indications for use, intended use, and a basic design in which the user places an emitter focused on the target body region (predicate device #K151834) or the patient lies on a body pad (predicate device #K210174) in order to facilitate electrical stimulation of affected body parts. All three devices meet EM compatibility and electrical safety standards. In general, these three devices are substantially equivalent since they share basic designs and are used repeatedly in order to achieve the desired clinical effect.
Comparison of the LIMFA Therapy System's Emitter (subject device) to the BEMER Classic Set's B.SPOT Emitter
| | Subject Device
LIMFA Therapy System's Emitter
Eywa S.r.l.
(This Submission) | Predicate Device #1
BEMER Classic Set's B.SPOT BEMER Int. AG
(K151834) | Equivalence |
|---|---|---|---|
| Class | II | II | Equivalent
The class is the same |
| Product Code | NGX | NGX | Equivalent
The product code is the same |
| Regulation | 21 CFR 890.5850 | 21 CFR 890.5850 | Equivalent
The regulation is the same |
Page 8
| | Subject Device
LIMFA Therapy System's Emitter
Eywa S.r.l.
(This Submission) | Predicate Device #1
BEMER Classic Set's B.SPOT BEMER Int. AG
(K151834) | Equivalence |
|---|---|---|---|
| Indications for Use | To temporarily increase local blood circulation in healthy leg muscles.
To stimulate healthy muscles in order to improve and facilitate muscle performance | To temporarily increase local blood circulation in healthy leg muscles.
To stimulate healthy muscles in order to improve and facilitate muscle performance | The statements are the same
Devices are equivalent |
| Site of use | Hospitals, physician offices and home | Same | Sites of use are the same
Devices are equivalent |
| System Components | 1. Control unit (console)
2. Emitters (max. 2 emitters connected to a console)
3. AC/DC power adapter | 1. B.Box Classic Control unit (console)
2. B.SPOT (max 2 emitters connected to a console)
3. AC/DC power adapter | Equivalent
The systems have comparable components |
Technical Characteristics
| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Primary Mode of Action | Non-invasive tissue stimulation via magnetic field induction | Same | The primary mode of action is the same. |
| Devices are equivalent | |||
| Waveform | Pulsed asymmetric, variable amplitude during treatment | Pulsed asymmetric, constant amplitude during treatment | Equivalent |
| The Limfa Therapy System delivers different frequencies by modulating both the waveform type and the pulse amplitude, allowing the system to |
Page 9
| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| generate complex therapeutic signals using multiple waveform shapes. In contrast, the predicate device (Bemer) achieves frequency variation by adjusting the duration of a fixed waveform—specifically a sinusoidal pulse—while keeping amplitude relatively constant. |
Therefore, while the predicate device is limited to sine wave modulation with variable pulse widths, the Limfa system achieves comparable therapeutic frequencies using a broader range of waveform dynamics, including controlled variation in amplitude.
Despite these differences in signal construction, both systems remain within comparable frequency and intensity ranges, supporting substantial equivalence. |
| Wave Shape | Variable, bipolar | Sinusoidal, monopolar | Equivalent
While the predicate device utilizes a monopolar sinusoidal waveform, Limfa employs a variable, bipolar waveform, which allows for more flexible signal shaping and improved field symmetry.
Bipolar waveforms are widely used in PEMF literature and are considered advantageous for reducing net charge accumulation in tissues and for enhancing waveform balance and reproducibility.
Despite this difference, both systems deliver low-frequency pulsed electromagnetic stimulation within comparable intensity ranges, achieving the same therapeutic objective. |
| Pulse repetition rate | 2 – 80 Hz | 10 – 30 Hz | Both devices operate within the Extremely Low Frequency (ELF) range (typically defined as 0–100 Hz).
The Limfa Therapy System uses frequencies between 2–80 Hz, while the predicate device operates between |
Page 10
| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| 10–30 Hz. These frequency ranges overlap, and both fall well within the established therapeutic ELF window used in PEMF therapy. |
Therefore, despite Limfa offering a broader frequency range, the core therapeutic frequencies are comparable, supporting substantial equivalence. |
| Single pulse duration | Fixed 1 µS | 10 – 33 µS | The Limfa Therapy System and the Bemer device deliver PEMF signals using different waveform generation methods, but achieve the same therapeutic goal.
Limfa uses ultra-short bipolar pulses (1 µs) at a carrier frequency of 100 kHz, modulated at therapeutic frequencies (e.g., 10 Hz). This approach enables precise shaping of the waveform and minimizes tissue polarization.
In contrast, the Bemer system applies monopolar sinusoidal pulses directly at 10–30 Hz, with frequency modulation achieved through varying the pulse width.
The waveform comparison (see figure) shows that while the carrier and waveform structures differ, both systems deliver comparable low-frequency electromagnetic stimulation in the ELF range (0–100 Hz), and thus remain substantially equivalent in safety and intended therapeutic effect. |
| Average Flux Density | Up to 190 µT | Up to 100 µT | Equivalent
The subject device has a higher average flux density compared to the predicate device. However, this difference does not impact safety and effectiveness. The slightly higher value for the subject device remains within the safe exposure limits defined by ICNIRP and IEC 60601 standards for low-frequency magnetic fields. |
Page 11
| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Maximum output voltage | N/A | N/A | Equivalent |
| Maximum Output Current | Current directly applied to the patient's body |