(291 days)
- 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
accufit (subject device) when using the Biphasic/Interferential (4P) waveforms is a noninvasive powered muscle stimulator used to provide an electrical stimulation of muscles for muscle re-education. The accufit is used on an outpatient basis under the supervision of a clinician.
The accufit is the result of a close collaboration between Lutronic Corporation and Mettler Electronics, Corporation. Mettler is the manufacturer of both the subject and predicate device. Using the Mettler Sys*Stim ME240 (K113017) as a starting point, the accufit utilizes two of the original and unchanged waveforms for muscle reeducation.
There are four preprogrammed treatment regimens that enable users to mimic common physical exercises. Each treatment regimen has recommended treatment electrode placement depicted in both the accufit operator's manual and on the accufit graphic user interface (GU). The IntelliSTIM treatment electrodes have been designed to support the accufit and are controlled by an intelligent real-time impedance feedback Mettler System. The IntelliSTIM are held in place with hydrogel adhesive strips and Velcro body wraps. The user may select the treatment duration of either 15, 30 or 45 minutes. The size, type of electrode and technical/performance characteristics.
This document is a marketing submission for a medical device (510(k)). It describes the "accufit" powered muscle stimulator and its associated electrodes ("IntelliSTIM" and "IntelliGEL"). The submission aims to demonstrate substantial equivalence to previously cleared predicate devices, rather than presenting a study to prove acceptance criteria for a novel device with new performance claims.
Therefore, the typical acceptance criteria and study design for performance claims (e.g., sensitivity, specificity, accuracy against a gold standard, or comparative effectiveness studies) are not applicable in the context of this 510(k) summary. The "acceptance criteria" here are essentially the demonstration that the new device is as safe and effective as the predicate device based on its design, technical specifications, and compliance with recognized standards.
However, I can extract the information on the technical specifications and performance testing that were conducted to support the claim of substantial equivalence.
Here's a breakdown of the requested information based on the provided text, adapted to the context of a 510(k) submission for substantial equivalence:
1. Table of Acceptance Criteria and the Reported Device Performance
As this is a 510(k) showing substantial equivalence, the "acceptance criteria" are not framed as specific performance metrics against a disease state or outcome. Instead, the criteria are the demonstration of comparable technical characteristics and compliance with relevant safety and performance standards to the predicate device. The "reported device performance" is the accufit's (and its electrodes') specifications and test results, which are shown to be identical or substantially equivalent to the predicate devices and compliant with standards.
Here's a summary of the key comparisons and performance aspects for the accufit powered muscle stimulator:
| Characteristic (Acceptance Criteria for SE) | accufit (Reported Performance) | Predicate (Mettler Sys*Stim ME240, K113017) (Reference) | Basis for Equivalence/Comment |
|---|---|---|---|
| Indications for Use (Applicable Waveforms) | 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 | Same indications for Biphasic and Interferential (4P) waveforms. (Predicate has additional indications for other waveforms not present in accufit) | Identical for the shared waveforms. |
| Waveforms Generated | 2 (Biphasic and Interferential (4P)) | 9 (including Biphasic, Interferential (4P), Medium Frequency (Russian), HVPC, Premodulated (2P), Microcurrent, TENS, DC) | accufit uses a subset of identical waveforms. Claim of SE limited to these two. |
| Waveform Shape | Square (Biphasic), Sinusoidal (Interferential (4P)) | Square (Biphasic), Sinusoidal (Interferential (4P)) | Identical |
| Max Output Voltage (Biphasic) | 104 @ 500Ω; 197 @ 2kΩ; 178 @ 10kΩ | 104 @ 500Ω; 197 @ 2kΩ; 178 @ 10kΩ | Identical |
| Max Output Current (Biphasic) | 106 @ 500Ω; 49 @ 2kΩ; 9 @ 10kΩ | 106 @ 500Ω; 49 @ 2kΩ; 9 @ 10kΩ | Identical |
| Pulse Width (Biphasic) | 40-800 µSec | 40-800 µSec | Identical |
| Frequency (Biphasic) | 1-200 Hz | 1-200 Hz | Identical |
| Electrical Safety (IEC 60601-1, -1-2, -2-10) | Found to be in compliance | Predicate was compliant. | Device tested and confirmed compliant with the same standards as the predicate. |
| Software V&V (ISO 62304, FDA Guidance) | Software V&V testing conducted; documentation provided; moderate level of concern (FDA), Class B (ISO 62304) | Predicate was considered compliant. | Testing conducted per recognized guidance; no new safety/effectiveness questions raised. |
Here's a summary of the key comparisons and performance aspects for the IntelliSTIM and IntelliGEL electrodes:
| Characteristic (Acceptance Criteria for SE) | IntelliSTIM & IntelliGEL (Reported Performance) | Predicate (Self-adhesive Electrode, K222252) (Reference) | Basis for Equivalence/Comment |
|---|---|---|---|
| Regulation & Product Code | 21 CFR 882.1320, GXY | 21 CFR 882.1320, GXY | Identical |
| Classification Name | Cutaneous electrode | Cutaneous Electrode | Identical |
| Biocompatibility | ISO 10993 compliant (ISO 10993-5 (cytotoxicity), ISO 10993-10 (irritation, sensitization) for IntelliGel) | ISO 10993 compliant | Tested and compliant with ISO 10993 standards; no appreciable risk detected. |
| Electrical Safety (ANSI AAMI ES60601-1) | Compliant | Compliant | Identical compliance with standard. |
| AC Impedance | <200Ω | <300Ω | Substantially Equivalent (better performance); ensures safety against burns. |
| Adhesive Strength | >185g/in (using a different methodology than predicate) | ≥7N | Stronger in subject device due to design for exclusive use. |
| Conductive Component | Copper coated carbon film | Silver coated carbon film | Both are highly conductive; copper chosen for strength in reusable accessory; tested biocompatible. |
| Intended Use | Forms a conductive adhesive interface between the accufit and the patient’s skin. | Reusable, conductive adhesive interface between patient's skin and marketed electrical stimulators (TENS, EMS, IF, PGF) for transmitting electrical current. | Substantially equivalent function, though IntelliSTIM is specific to accufit. |
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
This information is not provided in the document as it's not a clinical study with a "test set" in the traditional sense of evaluating a new performance claim against a ground truth dataset. The testing performed consists of:
- Bench Testing: To ensure compliance with electrical safety, EMC, and powered muscle stimulator standards. These are engineering verification tests, not clinical evaluations on patient data.
- Biocompatibility Testing: Conducted on the IntelliGel hydrogel adhesive strips according to ISO 10993 standards. These tests are typically performed in a lab on material samples and don't involve a "patient test set" or clinical data provenance.
- Software Verification and Validation Testing: Performed on the accufit's software. This is also an engineering/software quality assurance process, not a data-driven clinical performance study.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)
Not applicable. As described above, there was no clinical "test set" requiring ground truth established by experts for performance evaluation against a diagnostic or therapeutic outcome. The "ground truth" for the performed tests is adherence to recognized performance standards (e.g., the output voltage/current should be within a certain range as per engineering specifications, or a material should not cause cytotoxicity based on ISO 10993).
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. No clinical test set or adjudication process for clinical outcomes was described.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. The device is a powered muscle stimulator, not an AI-assisted diagnostic or interpretive tool that would involve "human readers" or "AI assistance" in the sense of image interpretation or similar cognitive tasks.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. This device is a powered muscle stimulator, not an algorithm. Its operation inherently involves human interaction (clinician supervision, patient interrupt switch).
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
Not applicable. For the purposes of this 510(k), the "ground truth" for the device's substantial equivalence is its compliance with internationally recognized safety and performance standards (e.g., IEC 60601 series, ISO 10993 for biocompatibility) and the demonstration that its technical specifications (e.g., output characteristics like voltage, current, pulse width) either match or are equivalent to those of the predicate device for the claimed indications.
8. The sample size for the training set
Not applicable. This device is not an AI/ML product developed using a "training set" of data.
9. How the ground truth for the training set was established
Not applicable. There was no training set for an algorithm.
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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services seal on the left and the FDA acronym along with the full name of the agency on the right. The FDA part of the logo is in blue, with the acronym in a square and the full name written out to the right of the square.
October 6, 2023
Mettler Electronics Corporation An Le QS/RA Manager 1333 South Claudina Street Anaheim. California 92805
Re: K223802
Trade/Device Name: accufit Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF Dated: October 5, 2023 Received: October 5, 2023
Dear An Le:
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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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 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 mediation-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,
Jitendra V. Virani -S
CDR Jitendra Virani, MS, MBA Assistant Director DHT5B: Division of Neuromodulation and Rehabilitation Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
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Indications for Use
510(k) Number (if known) K223802
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
Type of Use (Select one or both, as applicable)
| X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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FORM FDA 3881 (6/20)
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Mettler Electronics, Corporation Traditional 510k Submission accufit Powered Muscle Stimulator
21 CFR §890.5850
510(k) Summary – accufit (510k number K223802)
Mettler Electronics Corporation
accufit 510k Summary
l. Submitter
Mettler Electronics, Corporation 1333 South Claudina Street Anaheim, CA USA 92805
Contact Person Timothy Duggins Phone: 602-200-4981 Email: timd@horizonphoenix.biz Date Revised: March 27, 2023
II. Device
| Trade Name: | accufit |
|---|---|
| Usual Name: | powered muscle stimulator |
| Regulation Number: | 21 CFR 890.5850 |
| Regulation Name: | Powered Muscle Stimulator |
| Regulatory Class: | Class II |
| Product Code: | IPF |
lll. Predicate Device
Premarket Notification:
| Primary Predicate Device (for the accufit): | |
|---|---|
| Trade Name: | Mettler Sys*Stim ME 240, K113017 |
| Common or Usual Name: | powered muscle stimulator |
| Regulation Number: | 21 CFR 890.5850 |
| Regulation Name: | Powered Muscle Stimulator |
| Regulatory Class: | Class II |
| Product Code: | IPF, GZJ, ILY, LIH |
Secondary Predicate Device: Self-adhesive Electrode, K222252 for the IntelliSTIM and IntelliGEL
| Trade Name: | Self-adhesive Electrode |
|---|---|
| Common or Usual Name: | Cutaneous electrode |
| Regulation Number: | 21 CFR 882.1320 |
| Regulation Name: | cutaneous electrode |
| Regulatory Class: | Class II |
| Product Code: | GXY |
| Premarket Notification: | Shenzhen Roundwhale Technology Co., Ltd, K222252, (01/19/2023) |
Mettler Electronics K113017 (06/22/2012)
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IV. Device Description
accufit (subject device) when using the Biphasic/Interferential (4P) waveforms is a noninvasive powered muscle stimulator used to provide an electrical stimulation of muscles for muscle re-education. The accufit is used on an outpatient basis under the supervision of a clinician.
The accufit is the result of a close collaboration between Lutronic Corporation and Mettler Electronics, Corporation. Mettler is the manufacturer of both the subject and predicate device. Using the Mettler Sys*Stim ME240 (K113017) as a starting point, the accufit utilizes two of the original and unchanged waveforms for muscle reeducation.
There are four preprogrammed treatment regimens that enable users to mimic common physical exercises. Each treatment regimen has recommended treatment electrode placement depicted in both the accufit operator's manual and on the accufit graphic user interface (GU). The IntelliSTIM treatment electrodes have been designed to support the accufit and are controlled by an intelligent real-time impedance feedback Mettler System. The IntelliSTIM are held in place with hydrogel adhesive strips and Velcro body wraps. The user may select the treatment duration of either 15, 30 or 45 minutes. The size, type of electrode and technical/performance characteristics.
V. Indications for Use
As the accufit (subject device) and the Mettler Sys* Stim ME240 (predicate device K113017) have nearly identical technical and performance specifications. The two devices share the same indications for use considering the accufit uses only 2 of the Mettler Sys*Stim ME240 9 outputs/waveforms as indicated:
| Waveform | Indication for Use |
|---|---|
| Biphasic, Interferential (4P) | 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 |
VI. Comparison of the technology characteristics with the predicate device
Mettler Electronics, Corporation believes that the accufit described herein and for use under the conditions of the proposed labeling is substantially equivalent to the Mettler Sys*Stim ME240, predicate device (K113017). Owing to the close collaboration between Lutronic Corporation and Mettler Electronics the subject and predicate device have nearly identical Technical Characteristics.
{5}------------------------------------------------
21 CFR §890.5850 Utilizing FDA's Guidance for Industry and FDA Staff "Format for traditional and Abbreviated 510(k)s", the accufit (subject device) is substantially equivalent to the Mettler Sys*Stim ME 240 (predicate device K113017).
Indications for Use
The accufit (subject device) and the Mettler Sys*Stim ME240 (predicate device K113017) have the following identical indications for use considering the two common waveforms (Biphasic and Interferential (4P) bolded).
| Waveform | accufit | ME240 (K113017) | Comment |
|---|---|---|---|
| BiphasicInterferential (4P) | Relaxation of muscle spasms, Preventionor retardation of disuse atrophy, Increaselocal blood circulation, Muscle re-education, Maintaining or increasing rangeof motion, Immediate post-surgicalstimulation of calf muscles to preventvenous thrombosis | Relaxation of muscle spasms,Prevention or retardation of disuseatrophy, Increase local bloodcirculation, Muscle re-education,Maintaining or increasing range ofmotion, Immediate post-surgicalstimulation of calf muscles toprevent venous thrombosis | Identical |
| Microcurrent,Interferential (4P),Premodulated (2P3),Biphasic and TENSwaveforms | Not applicable. | Symptomatic relief andmanagement of chronic, intractablepain, Post-traumatic acute pain,Post-surgical acute pain | See Note below. |
| DC (Direct Current)Mode | Not applicable. | Relaxation of muscle spasm | See Note below. |
| Laser and clusterapplicators of theSys*Stim 240emitinfrared energy | Not applicable. | Temporary increase in bloodcirculation, Temporary relief ofminor muscles and joint aches,pains and stiffness, relaxation ofmuscles, temporary relief of musclespasms, temporary relief of minorpain and stiffness associated witharthritis. | See Note below. |
NOTE: The ME 240 (predicate device K113017) has other modes (Microcurrent, Premodulated (2P3), TENS, DC (direct current), and laser/cluster applicators which are NOT present in the acufit (subject device). There is no claim of substantial equivalency with these modes and their indications for use.
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Powered Muscle Stimulator
21 CFR §890.5850
| Characteristic | accufit510k -K223802(subject device) | Mettler Sys*Stim ME240,K113017 (predicate device) | 21 CFR §890.5850Substantial equivalence discussion |
|---|---|---|---|
| Manufacturer | Mettler Electronics Corporation | Mettler ElectronicsCorporation | Identical |
| Classification | Class II- 890-5850 - IPF | Class II- 890-5850 - IPF, GZJ,ILY, LIH | Identical |
| Power Source | 100-240VAC, 50/60Hz, 1.0A(Fuse: 250V / 6.3A) | 100-240VAC, 50/60Hz, 1.0A(Fuse: 250V / 6.3A) | Identical |
| Therapeutic Modality | Electrical muscle stimulator | Electrical muscle stimulator | Identical |
| Treatment Output Mode | Electrode | Electrode | Identical |
| Method of Line Current Isolation | Double Insulated WireNon- Conductive Enclosure | Double Insulated WireNon- Conductive Enclosure | Identical |
| Measured Patient Leakage: | |||
| Normal Condition (μ A) | Less than 100µA | Less than 100µA | Identical |
| Single Fault Condition (µA) | Less than 500µA | Less than 500µA | Identical |
| Number of Output Modes | 2 | 9 | See Note #7. |
| Number of Output Channels | 2 | 2 | Identical |
| Regulated Current or Voltage? | Current = 100mA maximum | Current = 100mA maximum | Identical |
| Synchronous or Alternating | Synchronous Channel 1&2 | Synchronous Channel 1&2 | Identical |
| Constant Current | NA | Optional | See Note #5. |
| Constant Voltage | NA | Optional | See Note #5. |
| Method of Channel Isolation | Line current isolation | Line current isolation | Identical |
| Pulse Intensities | Adjustable, 0-100 mA peak into 500ohmload each Electrode channel | Not known | See Note #6. |
| Software/Firmware/MicroprocessorControl? | Yes | Yes | Substantially Equivalent see Note#1 |
| Automatic Overload Trip? | Yes | Yes | Identical |
| Automatic No Load Trip? | Yes | Yes | Identical |
| Automatic Shut Off? | Yes | Yes | Identical |
| Patient Override Control? | Patient Interrupt (Stop) Switch | Patient interrupt Switch | Identical |
| Indicator Display: | Yes | Yes | Substantially Equivalent see Note#1 |
| On/ Off Status? | Yes | Yes | Substantially Equivalent see Note#1 |
| Low Battery? | NA | Yes | NA See Note #3. |
| Voltage/ Current Level? | Yes | Yes | Substantially Equivalent see Note#1 |
| Timer range | 15, 30, 45 mins | 0 - 60 minutes | Substantially Equivalent see Note#2 |
| Compliance: Voluntary Standards | IEC 60601-1; 60601-1-2; 60601-2-10, ISO14971, UL 60601, CSA C22.2 No 606.1,MDD 93/42/EEC, Annex II | IEC 60601-1; 60601-1-2;60601-2-10, ISO 14971, UL60601, CSA C22.2 No 606.1,MDD 93/42/EEC, Annex II | Identical |
| Compliance: 21 CFR 898 | Yes | Yes | Yes |
| Weight | 27 kg | 4.5 lbs.,5.5 lbs. with battery | See Notes #3 and #4. |
| Dimensions (mm) W x L x H | 452 x 582 x 1101 | 8 inches (H) x 8 inches(W) x 13 inches (L) | See Note #4 |
| Housing, Materials and Construction | ABS plastic | ABS plastic | Identical |
| Powered Muscle Stimulator Device | accufit 510k - K223802 | Mettler SysStim ME240 -K113017 (predicate device) | SubstantialEquivalence Discussion |
| (subject device) | |||
| Waveforms | 2 (Biphasic and Interferential (4P)) | Medium Frequency (Russian),Biphasic, High Volt PulsedCurrent (HVPC), Interferential(4P), Premodulated (2P),Microcurrent, TENS and DC(Direct Current) Mode | DifferentSee Note #2 |
| Shape | Square (Biphasic)Sinusoidal (Interferential (4P)) | Square (Biphasic) Sinusoidal(Interferential (4P)) | Identical |
| Maximum Output Voltage (Biphasic)(Volts, peak to peak) | 104 @ 500Ω; 197 @ 2kΩ; 178 @ 10kΩ | 104 @ 500Ω; 197 @ 2kΩ; 178 @10kΩ | Identical |
| Maximum Output Voltage (Interferential(4P)) (Volts, peak to peak) | 106 @ 500Ω; 144 @ 2kΩ; 122 @ 10kΩ | 106 @ 500Ω; 144 @ 2kΩ; 122 @10kΩ | Identical |
| Maximum Output Current (Biphasic)(mA, ±20%) | 106 @ 500Ω; 49 @ 2kΩ; 9 @ 10kΩ | 106 @ 500Ω; 49 @ 2kΩ; 9 @10kΩ | Identical |
| Maximum Output Current(Interferential (4P)) (mA, ±20%) | 106 @ 500Ω; 35 @ 2kΩ; 6.3 @ 10kΩ | 106 @ 500Ω; 35 @ 2kΩ; 6.3 @10kΩ | Identical |
| Pulse Width (Biphasic) | 40-800 µSec | 40-800 µSec | Identical |
| Pulse Width (Interferential (4P)) | 200-400 µSec | 200-400 µSec | Identical |
| Frequency (Biphasic) | 1-200 Hz | 1-200 Hz | Identical |
| Frequency (Interferential (4P)) | 2.5 kHz, 4 kHz, 5 kHz | 2.5 kHz, 4 kHz, 5 kHz | Identical |
| For Interferential (4P) modes only: BestFrequency (Hz) | 1-250 Hz | 1-250 Hz | Identical |
| For Multiphasic waveforms only:Symmetrical phases? | Yes | Yes | Identical |
| Phase duration (Biphasic) - (μSec) | ~35 µSec | Not known | See Note #1. |
| Phase duration (Interferential (4P)) -(μSec) | 100, 125, 200 µSec | 100, 125, 200 µSec | Identical |
| Net Charge (μC micro Coulombs perpulse). If zero, method of achieving | Net Charge = 0 µC (Biphasic &Interferential (4P) pulses aresymmetrical about OV) | Net Charge = 0 µC(Biphasic &Interferential (4P) pulses aresymmetrical about 0V) | Identical |
| Duration of Primary (depolarizing) Phase | ~35 µSec | Not known | See Note #1. |
NOTE 1: In each device the software operates the GUI. In the case of the accufit the software only activates the 2 waveforms described, the Biphasic and the Interferential (4P). The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 2: The accufit uses identical levels of intensity however for a shorter duration. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
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Mettler Electronics, Corporation Traditional 510k Submission accufit Powered Muscle Stimulator
21 CFR §890.5850
Note 3: The accufit does not have a battery. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 4: The accufit is enclosed in an upright, wheeled configuration which is merely a branding initiative. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 5: The accufit does have these options. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 6: The accufit (subject device) and ME 240 (predicate device K113017) have identical electronic characteristics, therefore the difference in pulse intensities (if any) do not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 7: The accufit (subject device) and ME240 (predicate device K113017) generate identical (40) waveforms. The ME240 (predicate device K113017) generates six additional waveforms and one additional mode which are not found in the accufit (subject device). Substantially equivalency claim is limited only to the Biphasic and Interferential (4P) waveforms. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
VII. Comparison of the output specifications with the predicate device (K113017)
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Powered Muscle Stimulator
21 CFR §890.5850
| Pulse Duration | 360 µSec | Not known | See Note #1. |
|---|---|---|---|
| Maximum Phase Charge(µC) (Biphasic) | 42.4 µC, 500 Ω | 42.4 µC, 500 Ω | Identical |
| Maximum Phase Charge (Interferential(4P)) | 14.9 µC, 500 Ω | 14.9 µC, 500 Ω | Identical |
| Maximum Power Density (Biphasic) (usingsmallest electrode conductive surfacearea) | 0.043 W/cm², 500 Ω | 0.043 W/cm², 500 Ω | Identical |
| Maximum Power Density (Interferential(4P)) (using smallest electrode conductivesurface area) | 0.176 W/cm², 500 Ω | 0.176 W/cm², 500 Ω | Identical |
| Maximum Current Density (Biphasic) | 5.13 mA/cm², 500 Ω | 5.13 mA/cm², 500 Ω | Identical |
| Maximum Current Density (Interferential(4P)) | 5.196 mA/cm², 500 Ω | 5.196 mA/cm², 500 Ω | Identical |
| Burst Mode (pulse trains) | NA (no bursts) | NA (no bursts) | Identical |
| ON Time (seconds) | Biphasic 1 – 240Interferential (4P) NA | Not known | See Note #1. |
| OFF Time (seconds) | Biphasic 1 – 240Interferential (4P) NA | Not known | See Note #1. |
Note 1: The accufit (subject device) and ME 240 (predicate device K113017) have identical electronic characteristics, therefore the difference in these characteristics (if any) do not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 2: The accufit (subject device) and ME240 (predicate device K113017) generate identical (4P) waveforms. The ME240 (predicate device K113017) generates six additional waveforms and one additional mode which are not found in the accufit (subject device). Substantially equivalency claim is limited only to the Biphasic and Interferential (40) waveforms. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
The IntelliSTIM and IntelliGEL are substantially equivalent to the Self Adhesive Electrode predicate device (K222252) as shown in the following table:
| CharacteristicSee Note 1 | IntelliSTIMIntelliGELK223802Subject Device | Self-adhesive ElectrodePredicate DeviceK222252 | Discussion |
|---|---|---|---|
| Regulation | 21 CFR 882.1320 | 21 CFR 882.1320 | Identical |
| Product Code | GXY | GXY | Identical |
| Manufacturer | Mettler ElectronicsCorporation | Shenzhan RoundwhaleTechnology Co. Limited | NA |
| Classification Name | Cutaneous electrode | Cutaneous Electrode | Identical |
| Model Name | IntelliSTIM (electrodes)IntelliGEL (hydrogeladhesive) | Self-adhesive Electrodewith lead wire | See Note #1. |
| Common Name | Reusable NeurostimulationElectrode | Reusable NeurostimulationElectrode | |
| OTC/Prescription | Prescription | OTC and Prescription | See Note #5. |
| Target Population | General (Adult) | General (Adult) | Identical |
| Electrical Connection | Lead wire | Lead wire, snap button,Magnetic Button | IdenticalSee Note #2. |
| Size and Shape | Rectangular 60*70mm | Round 50±0.5cm),Rectangular (50*30±0.5mm), Square5050±0.5mm, Square4040±0.5mm, Oval40*80±0.5mm | Substantially EquivalentSee Note #2. |
| Protective Cover/Liner | ABS | PET | Substantially EquivalentSee Note #3. |
| Conductive Component | Copper coated carbon film | Silver coated carbon film | Substantially EquivalentSee Note #4. |
| Color | Red and Black | White | See Note #5. |
| Lead Wire Connector | .080.0.1" female socket orpin connector | .080/0.1" female socket orpin connector | Identical |
| Design Features | (1) Protective film lining ofthe applied part consistingof Polyethyleneterephthalate and Silicon;(2) the hydrogel with silverchloride substrate and (3) aliner protecting thehydrogel and the electrodeconsisting of Polyethyleneterephthalate and Silicon. | Six layers: 1.Insulationbacking material:Fabric/Foam/ Tan fabric2.Conductive film:Aluminum foil film /Carbonfilm/Carbon film coatedwith silver/ 3.Conductivehydrogel 4.Connection5.double sides adhesivetape 6.Release liner | See Note #1. |
| Reusable | Reusable | Reusable | See Note #1. |
| Single Patient Use | Yes | Yes | Identical |
| Biocompatibility | ISO 10993 compliant | ISO 10993 compliant | Identical |
| Sterile | Nonsterile only | Nonsterile only | Identical |
| Adhesive Type | Self-adhesive(biocompatible self-adhesive conductivehydrogel) | Self-adhesive | Identical See Note #1. |
| Electrical Safety | ANSI AAMI ES60601-1:2005/(R)2012 & A1:2012,C1:2009/(R)2012 &A2:2010/(R)2012 (Cons. Text)[Incl. AMD2:2021] , Medicalelectrical equipment - Part 1:General requirements for basicsafety and essentialperformance | ANSI AAMI ES60601-1:2005/(R)2012 & A1:2012,C1:2009/(R)2012 &A2:2010/(R)2012 (Cons. Text)[Incl. AMD2:2021] , Medicalelectrical equipment - Part 1:General requirements forbasic safety and essentialperformance | Identical See Note 5. |
| emc/emi | ANSI AAMI ES60601-1:2005/(R)2012 & A1:2012,C1:2009/(R)2012 &A2:2010/(R)2012 (Cons. Text)[Incl. AMD2:2021], Cl.8.5.2.3 | ANSI AAMI ES60601-1:2005/(R)2012 & A1:2012,C1:2009/(R)2012 &A2:2010/(R)2012 (Cons. Text)[Incl. AMD2:2021], Cl.8.5.2.3 | Identical |
| Biocompatibility | Complies with ISO 10933 | Complies with ISO 10933 | Identical |
| Force required to removewire from electrode | More than six pounds of force | More than six pounds of force | Identical |
| AC Impedance | <200Ω | <300Ω | SubstantiallyEquivalent - See Note 2. |
| Adhesive strength | >185g/in | ≥7N | See Note 6. |
| Indications for use | The IntelliSTIM and IntelliGelwhen used according to theaccufit operator's manualforms a conductive adhesiveinterface between the accufitand the patient's skin. | Self-Adhesive Electrode areintended for use as areusable, conductive adhesiveinterface between thepatient's skin and themarketed electricalstimulators (i.e. TENS(Transcutaneous ElectricalNerve Stimulation), EMS(Electrical MuscularStimulation), IF or IFC(Interferential) or PGF (PulsedGalvanic Stimulation) fortransmitting electricalcurrent. The electrode is forOTC (Over-The-Counter) orPrescription use. | Substantially Equivalent -See Note #1. |
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Mettler Electronics, Corporation Traditional 510k Submission accufit Powered Muscle Stimulator
21 CFR §890.5850
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Powered Muscle Stimulator
Note 1 – In each device the electrode floats above the patient through the use of a hydrogel pad. The accufit IntelliStim electrode and IntelliGel self-adhesive hydrogel pad forms an identical combination to the predicate device (K22252) however the IntelliStim electrode being separate is reusable. The IntelliGel pad is disposable. The Self Adhesive Electrodes [Predicate Device, K222252] is a substantially equivalent combination of electrode and hydrogel pad however as the electrode and hydrogel pad are a single unit, therefore entire accessory is single use. The IntelliGEL are for use only with the accufit and no claims are made for use on any other device. The difference does not raise any new safety or effectiveness questions and each device has identical biocompatible safety and performance characteristics
Note 2 – The electrode's size is directly related to the area being treated. Its AC impedance, size and shape evenly distributes the electrical stimulation preventing burns or similar injuries. The IntelliSTIM electrode was purpose-developed for use the accufit and for no other device, there is no snap button or magnetic button required. There is no substantial equivalence claimed for any size of the Predicate's (K22252) Square 50*50±0.5mm electrode. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 3 – Both materials are thermoplastics with identical performance characteristics. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
21 CFR §890.5850
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Powered Muscle Stimulator
21 CFR §890.5850
Note 4 - Both copper and silver are highly conductive materials. Copper is used in the IntelliSTIM because the metal is stronger and therefore more suited for a reusable accessory. Both the subject and predicate device (K222252) were tested according to the ISO 10993 series of Standard and were found to have zero toxic, irritating or sensitization risks. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 5 – The IntelliSTIM electrode set is designed to be used with the accufit and no other device. The Self-adhesive Electrode (K22252)is designed to be used with multiple devices. The IntelliSTIM electrodes was included in the accufit's electrical safety and emc/emi testing; for example IEC 60601 clause 8.5.2.3, the combination accufit and IntelliSTIM electrode was found to be in compliance with all pertinent requirements. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
Note 6 - 185g/in was determined using a different methodology then that used in the predicate device (K22252). The adhesive strength is stronger in the subject device owing to having two elements (IntelliSTIM and IntelliGEL) instead of one and it was designed for exclusive use with the accufit. Design did not have to consider the variety of devices that the electrode/adhesive might be used on. The difference does not raise any new safety or effectiveness questions and each device has identical safety and performance characteristics.
VIII. Indications for Use Statement Comparison
The accufit (subject device) uses only two of the Mettler Sys*Stim ME240's waveforms/outputs:
| Waveform | accufit | ME240 (K113017) |
|---|---|---|
| Medium Frequency (Russian) | Not used | × |
| Biphasic | × | × |
| High Volt Pulsed Current (HVPC) | Not used | × |
| Interferential (4P) | × | × |
| Premodulated (2P3) waveforms | Not used | × |
| Microcurrent | Not used | × |
| Interferential (4P3) | Not used | × |
| Premodulated (2P) | Not used | × |
| DC (Direct Current) | Not used | × |
| Laser/cluster infrared | Not used | × |
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21 CFR §890.5850
IX. Performance Data
Biocompatibility
Testing
The accufit and the IntelliSTIM treatment electrodes have no meaningful biocompatibility risk or hazard as there is no patient contact.
The IntelliGel hydrogel adhesive strips biocompatibility evaluation was conducted in accordance with the FDA's Guidance for Industry and FDA Staff "Use of International Standard ISO 10993-1, "Biological Evaluation of Medical Devices Part 1: Evaluation and Testing within a Risk Management Process" using:
- a. ISO 10993-5, Biological evaluation of medical devices Part 5: Tests for in vitro cytotoxicity,
- b. ISO 10993-10, Biological evaluation of medical devices Part 10: Tests for Irritation and Sensitization,
No appreciable risk or hazard was detected.
Sterilization and Shelf-Life
The accufit, IntelliSTIM and IntelliGel are not provided sterile and does not need to be sterilized by the end user. The accufit and IntelliSTIM electrodes are cleaned with a soft cloth usually moistened with isopropyl alcohol or a gentle household cleaner. The IntelliSTIM treatment electrodes must have the hydrogel removed from the electrode using a lint free cloth soaked with 90% isopropyl alcohol. The IntelliGel expected service life is 2 years and has been established by accelerated shelf life testing.
Electrical Safety and Electromagnetic Compatibility (EMC)
Electrical safety and EMC testing were conducted on the accufit and IntelliSTIM treatment electrodes (including the hospital grade power cord and patient stop switch) by a duly accredited third party test laboratory whose scope includes electromedical equipment. In every instance the accufit and the IntelliSTIM treatment electrodes were found to be in compliance with:
- . IEC 60601-1, an International Standard on Medical electrical equipment general requirements for safety (FDA Recognition List Number 19-4);
- . IEC 60601-1-2, an International Standard on Medical electrical equipment, electromagnetic compatibility (FDA Recognition List Number 19-8);
- . IEC 60601-1-6, an International Standard on Medical electrical equipment – Part 1-6: General requirements for basic safety and essential performance – Collateral standard: Usability (FDA Recognition List Number 5-132), and
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Powered Muscle Stimulator
21 CFR §890.5850
- IEC 60601-2-10 an International Standard on Medical electrical equipment Part 2-10: . Particular requirements for the basic safety and essential performance of nerve and muscle stimulators (FDA Recognition List Number 17-16).
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" and ISO 62304 Medical device software — Software life cycle processes. The software for the accufit was considered as a "moderate" level of concern (FDA) and as a Class B (ISO 62304) since a failure of the software could result in minor injury to a patient or to a user of the device.
Performance Testing
No animal or clinical testing was required to demonstrate the accufit is safe and will perform as intended. Bench Testing was performed to ensure that the accufit performs as intended and documentation was provided. Testing included normal, single fault and multiple fault scenarios using the requirements of FDA recognized Standards for electrical safety, electromagnetic disturbances and powered muscle stimulators.
X. Conclusions
The accufit [subject device] and the ME240 (primary predicate device, K113017) emanate Biphasic/Interferential (4P) waveforms. The predicate device (K113107)has other modes and indications, but no claim of substantial equivalency is made for these. When used according to the accufit operator's manual, with only those two waveforms, the accufit has the identical intended use, identical indications for use, and the identical fundamental scientific technology and performance characteristics as the predicate device (K113017). The IntelliSTIM and IntelliGel (subject devices) have identical intended use, identical fundamental scientific technology and performance characteristics with the secondary predicate device the Selfadhesive electrode (K22252). The differences between the subject and primary (K113017) and secondary predicate device (K22252) are minor are NOT the result of any short coming or adverse event. Therefore, the accufit is as safe, as effective, and performs as well as the legally marketed predicate devices (K113017) and (K222252).
§ 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).