(227 days)
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.
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.
The provided FDA 510(k) clearance letter and summary for the Limfa Therapy System (K243165) do not describe a study involving "acceptance criteria and the study that proves the device meets the acceptance criteria" in the context of an AI/ML-driven medical device performance study, which is implied by the detailed questions about sample sizes, expert ground truth, MRMC studies, and training sets.
Instead, this submission focuses on demonstrating substantial equivalence to predicate devices (Bemer Classic Set, K151834 and K210174) based on:
- Indications for Use: Identical.
- Technological Characteristics: Similar primary mode of action (non-invasive tissue stimulation via magnetic field induction), comparable frequency and intensity ranges (ELF PEMF), and compliance with the same safety standards. Differences in waveform shape, pulse duration, and treatment timing are argued to be equivalent without raising new safety or effectiveness concerns.
- Safety and Performance Testing: Compliance with relevant electrical safety (IEC 60601-1, -1-2, -1-6, -1-11), software (EN 62304, EN 62366), quality/risk management (EN ISO 14971), and labeling standards (EN ISO 15223-1, IEC TR 60601-4-2).
The document explicitly states:
- "No animal testing of the subject device was necessary. The performance tests are sufficient."
- "No clinical testing of the subject device was necessary. The performance tests are sufficient."
This type of 510(k) submission, common for devices deemed substantially equivalent to existing, cleared devices, generally does not require new de novo clinical studies demonstrating effectiveness, especially if the device operates on the same principles and within similar parameters as its predicates. The "performance tests" mentioned refer to engineering and electrical safety testing, not clinical performance studies with patient outcomes or expert reviews.
Therefore, I cannot extract the information requested about acceptance criteria, test set details, expert ground truth, MRMC studies, standalone performance, or training set specifics from this document because such studies were not required or performed for this specific 510(k) clearance. The device is cleared based on its substantial equivalence to previously cleared devices through technical comparisons and compliance with relevant safety and performance standards.
FDA 510(k) Clearance Letter - Limfa Therapy System
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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
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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."
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K243165 510(k) SUMMARY
General Information
| Submitter | Eywa S.r.l. |
|---|---|
| Address | Eywa S.r.l.Via Pietrarubbia, 25/ERimini 47922Italy |
| 510(k) Number | K243165 |
| Correspondence Person | Thomas Lawson, PhD |
| Contact Information | Email: drthomlawson@gmail.comPhone: 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 |
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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
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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 DeviceLIMFA Therapy System's EmitterEywa S.r.l.(This Submission) | Predicate Device #1BEMER Classic Set's B.SPOT BEMER Int. AG(K151834) | Equivalence | |
|---|---|---|---|
| Class | II | II | EquivalentThe class is the same |
| Product Code | NGX | NGX | EquivalentThe product code is the same |
| Regulation | 21 CFR 890.5850 | 21 CFR 890.5850 | EquivalentThe regulation is the same |
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| Subject DeviceLIMFA Therapy System's EmitterEywa S.r.l.(This Submission) | Predicate Device #1BEMER 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 sameDevices are equivalent |
| Site of use | Hospitals, physician offices and home | Same | Sites of use are the sameDevices 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 | EquivalentThe 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 | EquivalentThe Limfa Therapy System delivers different frequencies by modulating both the waveform type and the pulse amplitude, allowing the system to |
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| 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 | EquivalentWhile 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 |
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| 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 | EquivalentThe 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. |
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| 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<5mA (acc. to IEC 60601-1) | Current directly applied to the patient's body<5mA (acc. to IEC 60601-1) | EquivalentUsing the same technology to apply the current in the form of indirect induction through an electromagnetic fieldBoth devices use the same safety standard (IEC 60601-1) and the same equivalent frequency to induce a similar quantity of current into the body to result in equivalent effectiveness. |
Treatment mode, Treatment time
| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Local Treatment | Local ApplicatorMax 2 applicators connected to consoleLocal treatment on skeletal muscles—to be used in separate locations (not at the same time)Treatment area restricted by applicator geometryIntensities 1 – 71-7 ProgramsIntensities Preset according to the program selectedTreatment time 20 to 53 minutes. Stimulation per treatment is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation. | SameSameIntensities 1 – 10Treatment time 8 minutesIntensities 3 – 10Treatment time 8 to 20 minutes | EquivalentEquivalentEquivalentEquivalentWhile the Limfa Therapy System offers a timer range of 20 to 53 minutes, compared to 8 to 20 minutes in the predicate device, this extended duration does not represent a significant change in clinical application or safety profile.Both devices operate within comparable frequency and intensity parameters. The additional time in Limfa simply allows for extended application when using lower duty cycles, without increasing the electromagnetic dose beyond what is already documented as safe and effective. Limfa's standard protocol is 1 treatment (20 to 53 minutes), 3 times a week, while the predicate device is recommended for daily use. Limfa's treatment stimulation is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation.Therefore, the increased timer flexibility does not alter the intended use or impact safety and effectiveness, and the two systems remain substantially equivalent in their therapeutic range. |
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| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Weight of the console | 3.5 kg | 1.3 kg | EquivalentThe difference is due to the fact that the LIMFA system has a passive heatsink cooling system that discharges onto the metal casing while the predicate devices have fan cooling and a plastic casing. This weight difference does not affect the usability or portability of the subject device in relation to that of the predicate devices. |
| Dimensions of the console | 34 x 19 x 6 cm | 32 x 32 x 7 cm | EquivalentThe small difference in dimensions of the consoles does not affect safety or effectiveness. |
| Dimensions of the Emitters | 11.7 x 6.3 x 2.7 cm | 13 x 13 x 3 cm | EquivalentThe modest dimensional differences are due to the orientation of the coils contained within the Emitters. The subject device's Emitter contains vertical coils in an oblong capsule with rounded edges. This shape concentrates the magnetic field over a narrow rectangular patch while keeping the Emitter thin, lightweight, and easy to strap in place at localized treatment areas. The Emitter of the predicate device has a horizontal coil that is contained in a circular, disc-like housing. Bench testing confirms that both Emitters deliver equivalent ranges of average flux density; consequently, the shape and size differences do not raise new safety or effectiveness concerns. |
| Power consumption | 36 Watt max | 30 Watt max | EquivalentThe extra 6 watts of the subject device does not affect safety or effectiveness |
| Input | 90-264 VAC47-63 Hz0.25–0.74A | 100-240 VAC50-60 Hz0.6 A | Equivalent |
| Output | 12 VDC0 – 5 A | 12-15.1 Vdc2.0 A | Equivalent |
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| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Biocompatibility | Yes | Yes | Equivalent |
| Number of output modes | 1 | 1 | Equivalent |
| Number of output channels and ports | 2 | 2 for each | Equivalent |
| Software Controlled | Yes | Yes | Equivalent |
| Voltage / Current Level | 1-7 programs using variable intensity | 1-10 intensity indicator | Equivalent |
| Timer Range | 20 to 53 minutes | 8 to 20 minutes | EquivalentThe extended duration of the subject device does not represent a significant change in clinical application or safety profile.Both devices operate within comparable frequency and intensity parameters. The additional time in Limfa simply allows for extended application when using lower duty cycles, without increasing the electromagnetic dose beyond what is already documented as safe and effective. Limfa's treatment stimulation is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation.Therefore, the increased timer flexibility does not alter the intended use or raise new questions of safety or effectiveness, and the two systems remain substantially equivalent in their therapeutic range. |
| Compliance with voluntary standards | EN 60601-1EN 60601-1-2EN 60601-1-6EN 62366EN 62304EN 62353IEC TR 60601-4-2EN ISO 14971EN ISO 15223-1 | IEC 60601-1IEC 60601-1-2EN 60601-1-6EN 62366EN 60601-1-11 | Equivalent |
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| Subject Device | Predicate Device #1 | Equivalence | |
|---|---|---|---|
| Sterilization | Not provided sterile | Not provided sterile | Equivalent |
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Comparison of the Limfa Therapy System's Body Mat (subject device) to the BEMER Classic B.Body Mat (predicate device #2).
| Subject DeviceLimfa Therapy SystemEywa S.r.l.Body Mat(This Submission) | Predicate Device #2BEMER Classic Set's B.BODY. BEMER Int. AG (K210174) | Equivalence | |
|---|---|---|---|
| Class | II | II | EquivalentThe class is the same |
| Product Code | NGX | NGX | EquivalentThe product code is the same |
| Regulation | 21 CFR 890.5850 | 21 CFR 890.5850 | EquivalentThe regulation is the same |
| 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 | EquivalentThe statements are the same |
| Site of use | Hospitals, physician offices and home | Same | Sites of use are the sameDevices are equivalent |
| System Components | 1. Control unit (console)2. Total Body Mat (max. 2 mats connected to the console)AC/DC power adapter | 1. B.Box Classic Control unit (console)2. B.BODY pad (max. 2 pads connected to the console)AC/DC power adapter | EquivalentThe systems all have comparable components |
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| Subject Device | Predicate Device #2 | Equivalence | |
|---|---|---|---|
| Primary Mode of Action | Non-invasive tissue stimulation via magnetic field induction | Non-invasive tissue stimulation via magnetic field induction | EquivalentThe primary mode of action is the same. |
| Treatment of large or multiple regions simultaneously | Yes | Yes | EquivalentThe treatments actions are the same. |
| Local Treatment | Local Applicator1 Body Mat connected to consoleLocal treatment on skeletal musclesTreatment area restricted by applicator geometry1-7 ProgramsIntensities Preset according to the program selectedTreatment time 20 to 53 minutes.Stimulation per treatment is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation. | Local Applicator (max 2 body pads) connected to consoleSameSameIntensities 1 – 6Treatment time 8 minsIntensities 1 – 10Treatment time 8 to 20 minutes | EquivalentEquivalentEquivalentEquivalentWhile the Limfa Therapy System offers a timer range of 20 to 53 minutes, compared to 8 to 20 minutes in the predicate device, this extended duration does not represent a significant change. |
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| Subject Device | Predicate Device #2 | Equivalence | |
|---|---|---|---|
| Both devices operate within comparable frequency and intensity parameters. The additional time in Limfa simply allows for extended application when using lower duty cycles, without increasing the electromagnetic dose beyond what is already documented as safe and effective. Limfa's standard protocol is 1 treatment (20 to 53 minutes) 3 times a week, while the predicate device is recommended for daily use.Limfa's treatment stimulation is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation.Therefore, the increased timer flexibility does not alter the intended use or impact safety and effectiveness. The two systems remain substantially equivalent in their therapeutic range. | |||
| Weight of the console | 3.5 kg | 1.3 kg | EquivalentThe difference is due to the fact that the LIMFA system has a passive heatsink cooling system that discharges onto the metal casing while the predicate devices have fan cooling and a plastic casing. This weight difference does not affect the usability or portability of the subject device in relation to that of the predicate devices. |
| Dimensions of the console | 34 x 19 x 6 cm | 32 x 32 x 7 cm | EquivalentThe small difference in dimensions of the consoles does not affect safety or effectiveness. |
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| Subject Device | Predicate Device #2 | Equivalence | |
|---|---|---|---|
| Dimensions of the full body mat | 170 x 75 x 2.2 cm | 180 x 60 x 2 cm | EquivalentThe dimensional difference of the two mats/pads do not affect safety or effectiveness of the two devices. |
| Average Flux Density | Up to 35.5 µT | Up to 35 µT (max level) | EquivalentThe subject device has an Average Flux Density that is similar to that of the predicate device. Therefore, this does not impact safety and effectiveness. |
| Power consumption | 36 Watt max | 30 Watt max | EquivalentThe extra 6 watts of the subject devices, required by the larger display, do not affect safety or effectiveness |
| Input | 90-264 VAC47-63 Hz0.25–0.74A | 100-240 VAC50-60 Hz0.6 A | Equivalent |
| Output | 12 VDC0 – 5A | 12-15.1 Vdc2.0 A | Equivalent |
| Biocompatible | Yes | Yes | Equivalent |
| Number of output modes | 1 | 1 | Equivalent |
| Number of output channels and ports | 2 | 2 | Equivalent |
| Software controlled | Yes | Yes | Equivalent |
| Voltage / Current Level | 1-7 programs using variable intensity | 1-10 intensity indicator | EquivalentThe intensity is related to the program the user chooses for applying the magnetic field. |
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| Subject Device | Predicate Device #2 | Equivalence | |
|---|---|---|---|
| Timer Range | 20 to 53 minutes | 8 to 20 minutes | EquivalentThe extended duration of the subject device does not represent a significant change in clinical application or safety profile.Both devices operate within comparable frequency and intensity parameters. The additional time in Limfa simply allows for extended application when using lower duty cycles (Limfa suggested duty cycle is 3 times a week, while the predicate device is recommended for daily use), without increasing the electromagnetic dose beyond what is already documented as safe and effective. Limfa's treatment stimulation is performed in intervals: 20 minutes of stimulation is followed directly by 10 minutes of no stimulation.Therefore, the increased timer flexibility does not alter the intended use or impact safety and effectiveness. The two systems remain substantially equivalent in their therapeutic range. |
| Compliance with voluntary standards | EN 60601-1EN 60601-1-2EN 60601-1-6EN 60601-1-11EN 62366EN 62304EN 62353IEC TR 60601-4-2EN ISO 14971EN ISO 15223-1 | IEC 60601-1IEC 60601-1-2EN 60601-1-6EN 60601-1-11EN 62366 | Equivalent |
| Sterilization | Not provided sterile | Not provided sterile | Equivalent |
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Biocompatibility testing
The components of the Limfa® Therapy system do not contact patient skin, so such testing was not required. They do contact user intact skin but are identified by the FDA as having low risk when in contact with intact skin. The cover of the Emitter is silicone. The cover of the Total Body Mat is phthalate-free PVC.
Software testing
According to the FDA's Guidance for Industry and FDA Staff, Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices, the software for this device is considered to have a "moderate" level of concern.
Performance Testing
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
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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.
Animal Testing
No animal testing of the subject device was necessary. The performance tests are sufficient.
Clinical Studies
No clinical testing of the subject device was necessary. The performance tests are sufficient.
Conclusion
The information submitted in this premarket notification confirms that the Limfa® Therapy System raises no new questions of safety and effectiveness and that it is substantially equivalent to the predicate devices.
§ 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).