(99 days)
The accufit is indicated for use for Relaxation of muscle spasms, Prevention or retardation of disuse atrophy, Increase local blood circulation, Muscle re-education, Maintaining or increasing range of motion, Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis, Improvement of abdominal tone, for strengthening of the abdominal muscles, for development of firmer abdomen, and Improvement of muscle tone and firmness, for strengthening muscles in arms, thighs and buttocks areas.
The principle of operation of the accufit device is to provide direct electrical stimulation of muscles which produces muscle contractions in and around the area of the treatment electrodes. The accufit generates electrical stimulation to contract the muscles to achieve the desired intended use using unique IntelliPhase waveforms and IntelliSTIM electrodes. It offers two unique IntelliPhase waveforms, Biphasic and Interferential (4P), that are designed to optimize muscle re-education and activation for patients. The four IntelliPhase waveform protocols are twist, hold, grip, and tap. Each protocol may be used for 15, 30, or 45 minutes. Not only are there four IntelliPhase protocols, but there is also a fully automated protocol (IntelliCycle) that integrates all the above listed waveforms in a comprehensive, interlaced series. This engages all the targeted muscles in a continuous program to maximize muscle effects with the touch of a button. accufit is both the proprietary-trade name and generic name. accufit is a supplement to existing treatments and does not replace any traditional treatment or therapy. The system console is the heart of the accufit and contains the Touch LCD/GUI, electrodes, and power supply module. The main console also includes a key switch used to turn the power on and off, and an emergency stop push button that quickly de-energizes the system in emergency situations. There are 4 casters in the console base that can be used when moving the system.
The accufit device is a Powered Muscle Stimulator (Product Codes IPF, NGX) indicated for various muscle-related therapies, including:
- Relaxation of muscle spasms
- Prevention or retardation of disuse atrophy
- Increase local blood circulation
- Muscle re-education
- Maintaining or increasing range of motion
- Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
- Improvement of abdominal tone, for strengthening of the abdominal muscles, for development of firmer abdomen.
- Improvement of muscle tone and firmness, for strengthening muscles in arms, thighs and buttocks areas.
The device operates by providing direct electrical stimulation to muscles, causing contractions using unique IntelliPhase waveforms (Biphasic and Interferential (4P)) and IntelliSTIM electrodes. It offers four IntelliPhase waveform protocols (twist, hold, grip, and tap), each usable for 15, 30, or 45 minutes, as well as a fully automated IntelliCycle protocol.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document details a clinical study primarily focused on the improvement of muscle tone and firmness, specifically for strengthening muscles in the arms. While acceptance criteria in a quantitative sense (e.g., a specific percentage increase in strength) are not explicitly stated, the study's overall finding that "most patients saw improvement in muscle strength" serves as the reported device performance against an implied criterion of demonstrating clinical effectiveness for its new indication.
Given the available information, here is a summary related to the clinical study and its findings:
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Device effectively strengthens arm muscles. | "most patients saw improvement in muscle strength from the initial to final treatment, as measured by the dynamometer." |
| Device is well-tolerated with no significant adverse events. | "There were no significant adverse events noted in the duration of the study." |
2. Sample Size and Data Provenance for Test Set
- Sample Size: 45 subjects were enrolled in the study.
- Data Provenance: Not explicitly stated regarding the country of origin. The study appears to be prospective as subjects were "enrolled" and "treated" with the device, and follow-up assessments were conducted.
3. Number and Qualifications of Experts for Ground Truth
Not applicable. This was a clinical study assessing the physiological effect of the device on muscle strength, not an AI/image-based diagnostic device requiring expert interpretation for ground truth. Muscle strength was measured objectively using a dynamometer.
4. Adjudication Method for Test Set
Not applicable. Muscle strength was measured using a dynamometer, which provides objective, quantitative data, thus negating the need for an adjudication method typically used for subjective assessments or interpretations.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The study described is a clinical trial assessing the direct effect of the device on muscle strength in human subjects.
6. Standalone (Algorithm Only) Performance
Not applicable. This device is a powered muscle stimulator for direct application to the human body, not an algorithm-only or AI-driven diagnostic tool. Its performance is intrinsically linked to human-device interaction.
7. Type of Ground Truth Used
The ground truth used in the clinical study was objective physiological measurement: muscle strength measured by a dynamometer at specified time points (baseline, final treatment, 30-day post-treatment, and 90-day post-treatment).
8. Sample Size for Training Set
Not applicable. This device is a physical therapeutic device, not an AI/machine learning model that requires a "training set" in the conventional sense of data-driven algorithm development. The "training" for the device would be its engineering and design based on established principles of electrical muscle stimulation.
9. How Ground Truth for Training Set Was Established
Not applicable, as there is no specific "training set" for the type of device described. The device's design and operational parameters would be based on scientific and engineering principles for powered muscle stimulators. Its effectiveness for specific indications is then demonstrated through clinical studies, as detailed above.
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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. Underneath the square are the words "U.S. FOOD & DRUG ADMINISTRATION" in blue.
March 21, 2024
Mettler Electronics Corporation Kevin O'Connell VP Global Regulatory Affairs Lutronic Corporation Lutronic Center 219, Sowon-Ro Deogyang-Gu, Goyang-Si 410220 South Korea
Re: K233926
Trade/Device Name: accufit Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF, NGX Dated: March 7, 2024 Received: March 7, 2024
Dear Kevin O'Connell:
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.
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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).
Your device is also subject to, among other requirements, the Quality System (OS) 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 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-reportingcombination-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.
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-device-safety/medical-device-reportingmdr-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/medicaldevices/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-device-advice-comprehensive-regulatoryassistance/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.
Heather L. Dean -S
Heather Dean, PhD Assistant Director, Acute Injury Devices Team DHT5B: Division of Neuromodulation
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Enclosure
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Indications for Use
510(k) Number (if known) K233926
Device Name accufit
Indications for Use (Describe)
- Relaxation of muscle spasms
- Prevention or retardation of disuse atrophy
- Increase local blood circulation
- Muscle re-education
- Maintaining or increasing range of motion
- Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
- Improvement of abdominal tone, for strengthening of the abdominal muscles, for development of firmer abdomen.
- Improvement of muscle tone and firmness, for strengthening muscles in arms, thighs and buttocks areas.
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)
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510(k) SUMMARY
K233926
A summary of 510(k) safety and effectiveness information in accordance with the requirements of 21 CFR 807.92.
| 807.92(a)(1) - Submitter Information | |
|---|---|
| Name | Mettler Electronics Corporation |
| Address | 1333 South Claudina StreetAnaheim, CA USA 92805 |
| Phone number | 978-888-1426 |
| Fax number | N/A |
| Name of contact person | An LeQS/RA Manager, Mettler Electronics Corporation1333 South Claudina StreetAnaheim, CA 92805 |
| Date prepared | March 19, 2024 |
| 807.92(a)(2) - Name of device | |
| Trade or proprietary name | accufit |
| Common or usual name | Powered Muscle Stimulator |
| Classification name | Stimulator, Muscle, Powered, For Muscle Conditioning |
| Classification panel | Physical Medicine |
| Regulation | 21 CFR 890.5850 |
| Product Code(s) | IPF, NGX |
| 807.92(a)(3) - Legally marketed device(s) to which equivalence is claimed | |
| Mettler Electronics Corporation K223802 (10/06/2023) PredicateJohari Digital Healthcare Limited K192039 (03/29/2020) ReferenceSport- Elec K092476 (05/07/2010) Reference | |
| 807.92(a)(4) - Device description | |
| The principle of operation of the accufit device is to provide directelectrical stimulation of muscles which produces muscle contractions inand around the area of the treatment electrodes.The accufit generates electrical stimulation to contract the muscles toachieve the desired intended use using unique IntelliPhase waveformsand IntelliSTIM electrodes. It offers two unique IntelliPhasewaveforms, Biphasic and Interferential (4P), that are designed tooptimize muscle re-education and activation for patients. The fourIntelliPhase waveform protocols are twist, hold, grip, and tap. Each | |
| protocol may be used for 15, 30, or 45 minutes. Not only are there fourIntelliPhase protocols, but there is also a fully automated protocol(IntelliCycle) that integrates all the above listed waveforms in acomprehensive, interlaced series. This engages all the targeted musclesin a continuous program to maximize muscle effects with the touch of abutton. | |
| accufit is both the proprietary-trade name and generic name. accufit is asupplement to existing treatments and does not replace any traditionaltreatment or therapy. | |
| The system console is the heart of the accufit and contains the TouchLCD/GUI, electrodes, and power supply module. The main consolealso includes a key switch used to turn the power on and off, and anemergency stop push button that quickly de-energizes the system inemergency situations. There are 4 casters in the console base that canbe used when moving the system. | |
| 807.92(a)(5) Intended use of the device | |
| Indications for use | The accufit is indicated for use for Relaxation of muscle spasms,Prevention or retardation of disuse atrophy, Increase local bloodcirculation, Muscle re-education, Maintaining or increasing range ofmotion, Immediate post-surgical stimulation of calf muscles to preventvenous thrombosis, Improvement of abdominal tone, for strengtheningof the abdominal muscles, for development of firmer abdomen, andImprovement of muscle tone and firmness, for strengthening muscles inarms, thighs and buttocks areas. |
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| 807.92(a)(6) Summary of the technological characteristics of the device compared to the predicate | |||||
|---|---|---|---|---|---|
| Model Name | accufit | accufit | Torc Body | Body ControlSystem "4M" | Notes |
| 510(k) # | Subject device | K223802 | K192039 | K092476 | |
| Manufacturer | Mettler | Mettler | Johari DigitalHealthcare Limited | Sport-Elec S.A | |
| Indications for Use | • Relaxation of musclespasms• Prevention orretardation of disuseatrophy• Increase local bloodcirculation• Muscle re-education• Maintaining orincreasing range ofmotion• Immediate post-surgical stimulation ofcalf muscles to preventvenous thrombosis• Improvement ofabdominal tone, forstrengthening of theabdominal muscles, fordevelopment of firmerabdomen.Improvement of muscletone and firmness, forstrengthening muscles inarms, thighs andbuttocks areas. | • Relaxation of musclespasms• Prevention orretardation of disuseatrophy• Increase local bloodcirculation• Muscle re-education• Maintaining orincreasing range ofmotion• Immediate post-surgical stimulation ofcalf muscles toprevent venousthrombosis | • Improvement ofabdominal tone, forstrengthening of theabdominal muscles,for development offirmer abdomen.• Strengthening, toningand firming ofbuttocks & thighs. | Improvement ofmuscle tone andfirmness, forstrengtheningmuscles in arms,abdomen, thighs andbuttocks areas. | Identical to predicateplus referencedevices |
| Classification | 890-5850 - IPF, NGX | 890-5850 - IPF | 890-5850 - NGX | 890-5850 - NGX | Identical topredicate plusreference devices |
| Power Source | 100-240VAC ,50/60Hz, 1.0A (Fuse:250V / 6.3A) | 100-240VAC ,50/60Hz, 1.0A(Fuse: 250V / 6.3A) | 100-240AC,50/60Hz, 75VA | Battery powered | Identical |
| TherapeuticModality | Electrical musclestimulator | Electrical musclestimulator | Electrical musclestimulator | Electrical musclestimulator | Identical |
| Treatment OutputMode | Electrode | Electrode | Electrode | Electrode | Identical |
| Method of LineCurrentIsolation | Double Insulated WireNon- ConductiveEnclosure | Double InsulatedWire Non-ConductiveEnclosure | (a) AC Power supplyis converted to DCPower supplythrough a medicalgrade PSU.(b) Isolation thrutransformer inbetween device andpatient | Not available | Same as predicate |
| Measured PatientLeakage: | |||||
| Normal Condition(μ Α) | Less than 100μA | Less than 100μA | Less than 100μA | Not available | Identical |
| Single FaultCondition (μΑ) | Less than 100μA | Less than 100μA | Less than 300μA | Not available | Similar |
| Number of OutputModes | 4 | 4 | 3 | Not available | 1 additional mode |
| Number of OutputChannels | 2 | 2 | 2 | 2 | Identical |
| Regulated Currentor Voltage | Current = 100mAmaximum | Current = 100mAmaximum | 103.2 mA pp @ 500Ohm 31.2 mA pp @2K Ohm 6.6 mA pp@ 10K Ohm | Not available | Identical whencompared at 500Ohm |
| Pulse Intensities | Adjustable, 0-100 mApeak into 500ohm loadeach Electrode channel | Adjustable, 0-100mA peak into500ohm load eachElectrode channel | Not available | Not available | Same as predicate |
| Software/Firmware/MicroprocessorControl | yes | yes | yes | Not available | Identical |
| Automatic OverCurrent Trip? | yes | yes | yes | Not available | Identical |
| Automatic No LoadTrip? | yes | yes | no | Not available | Same as predicate |
| Automatic ShutOff? | yes | yes | yes | Not available | Identical |
| User Overridecontrol? | Patient Interrupt (Stop)Switch | Patient Interrupt(Stop) Switch | yes | Not available | Identical |
| Indicator Display: | yes | yes | yes | Not available | Identical |
| On/ Off Status? | yes | yes | yes | Not available | Identical |
| Voltage/ CurrentLevel? | yes | yes | yes | Not available | Identical |
| Timer range | 15, 30, 45 mins | 15, 30, 45 mins | 1 – 60 Minutes Instep of 1 minute | Not available | Similar |
| Compliance:VoluntaryStandards | IEC 60601-1; 60601-1-2; 60601-2-10, ISO14971, UL 60601,CSA C22.2 No 606.1 | IEC 60601-1;60601-1-2; 60601-2-10, ISO 14971, UL60601, CSA C22.2No 606.1 | YES IEC 60601-1,IEC 60601-1-2,IEC60601-2-10,and ISO14971 | Not available | Similar |
| Compliance: 21CFR 898 | yes | yes | yes | Not available | Identical |
| Weight | 27 Kg | 27 Kg | 32.66 Kgs | Not available | Similar |
| Dimensions (mm)W x L x H | 452 x 582 x 1101 | 452 x 582 x 1101 | 444 x 356 x 1016 | 84x126x30 | Similar |
| Housing, Materialsand Construction | ABS plastic | ABS plastic | ABS Plastic Body | Not available | Identical |
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| Medical EquipmentClassification | Type BF | Type BF | Not available | Not available | Identical |
|---|---|---|---|---|---|
| 807.92(b)(1) NON CLINICAL TESTS SUBMITTED | |||||
| IEC 60101-1, an International Standard on Medical electrical equipment general requirements for safety (FDA Recognition ListNumber 19-4); IEC 60601-1-2, an International Standard on Medical electrical equipment, electro- magnetic compatibility (FDA Recognition ListNumber 19-8); IEC 60601-1-6, an International Standard on Medical electrical equipment – Part 1-6: General requirements for basic safety andessential performance – Collateral standard: Usability (FDA Recognition List Number 5-132), IEC 60601-2-10 an International Standard on Medical electrical equipment - Part 2-10: Particular requirements for the basic safetyand essential performance of nerve and muscle stimulators (FDA Recognition List Number 17-16), and 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 (FDA Recognition List Number 19-19). IEC 62304 Medical device software - Software life cycle processes (FDA Recognition List Number 13-79) Cytotoxicity per ISO 10993-5:2009 Skin sensitization per ISO 10993-10:2021 Skin Irritation per ISO 10993-23:2021 | |||||
| 807.92(b)(2) CLINICAL TESTS SUBMITTED | |||||
| A clinical study was performed to assess the effect of the device on the strengthening and appearance of arms. 45 subjects were enrolled in thestudy and treated with this bioelectric muscle activation (BMA) device. Strength was measured with a dynamometer device at baseline, at thefinal treatment session, and at the posttreatment 30- and 90-day assessment. The device was tolerated, and most patients saw improvement inmuscle strength from the initial to final treatment, as measured by the dynamometer. There were no significant adverse events noted in theduration of the study. |
807.92(b)(3) Conclusion
Based on the companison of the technological characteristics, the specifications for the same or a subset of the Tore Body specifications. The options of two sized electrodes allow the users more options in how the same energy is shaped during delivery. The new indication of strengthening arms is supported by clinical testing. Also, the same as the reference device, SPORT-ELEC BODY CONTROL SYSTEM, MODEL 4M. Therefore, we believe that the subject device 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).