The BACK 4 device in RF mode is intended to provide topical heating for the purpose of elevating tissue temperature for the treatment of selected medical conditions such as relief of pain, muscle spasms, and increase in local circulation. The BACK 4 massage device is intended to provide a temporary reduction in the appearance of cellulite.

The BACK 4 device in EMS mode is intended for:
*Prevention or retardation of disuse atrophy
*Increasing local blood circulation
*Muscle re-education
*Maintaining or increasing range of motion.

The RF treatment mode and EMS mode should not be used in combination or sequentially.

Device Description

The BACK 4 device generates high frequency sinusoidal current with a monopolar mode of application using two electrodes. A neutral electrode is placed in contact with the patient and a handheld active electrode is manipulated by a therapist. When both electrodes are in contact with a patient the electrical circuit is closed and RF therapy can be provided. The device can be operated in a capacitive or resistive monopolar modes and a multipolar mode.

The product consists of a power console, LCD monitor, and accessories including capacitive, resistive and multipolar electrodes. The unit can be adjusted to provide various levels of treatment frequency ranging from 300kHz to 1MHz.

The product can also employ EMS technology. It generates a 4kHz or 1.5kHz electrostimulation signal (modulated at a frequency set between 2Hz and 200Hz).

The two RF and EMS technologies should not be used in combination or sequentially.

An Emergency stop button feature allows the patient to shut down the unit in the event of any discomfort.

AI/ML Overview

The provided text describes the regulatory clearance of a medical device (BACK 4) through a 510(k) premarket notification. The core of a 510(k) submission is demonstrating substantial equivalence to a legally marketed predicate device. This typically involves showing that the new device is as safe and effective as the predicate, often through performance testing.

However, the provided document focuses heavily on comparing the technical characteristics and intended uses of the BACK 4 device to two predicate devices (BACK3 COLOR and Evolve System with T3 Applicator). It lists various performance parameters and notes where the BACK 4 is identical or differs from the predicates, consistently concluding that these differences do not raise new questions of safety and effectiveness because the device underwent required performance testing and validation.

Crucially, the document explicitly states that performance testing was done, but does not provide specific acceptance criteria for these tests or detailed results that quantify the device's performance against said criteria. It highlights that tests were conducted according to relevant IEC standards for electrical safety, EMC, and software validation, and that a "tissue temperature elevation study" was performed for the RF mode.

Given this, I can only construct the table and address the other points based on the inference from the document that these tests were performed and deemed satisfactory for substantial equivalence, rather than providing concrete numerical acceptance criteria and reported numerical performance values. The document asserts that performance was "satisfactory" and "demonstrated conformity," implying that the device met internal or standard-driven criteria.

Here's a breakdown based on the provided text, addressing your points where information is available:

Acceptance Criteria and Device Performance

Due to the nature of this 510(k) summary (focusing on substantial equivalence to predicates rather than presenting de novo clinical trial data with explicit performance metrics), specific numerical acceptance criteria and reported device performance values are not provided in the document. The document primarily asserts that the device met its design requirements and applicable standards, implying that it met the necessary performance thresholds established for substantial equivalence to the predicate devices.

Table 1. Acceptance Criteria and Reported Device Performance (Inferred from Document)

Feature/Parameter	Acceptance Criteria (Inferred)	Reported Device Performance (Inferred)
RF Mode
Topical Heating	Equivalent to BACK3 COLOR (K214090) in elevating tissue temperature for pain relief, muscle spasms, increased local circulation, and temporary reduction of cellulite.	Demonstrated ability of all applicators to maintain therapeutic temperature (38-42°C on human skin) for these purposes, as confirmed by a human being testing study.
Target Temperature	Maintain therapeutic temperature between 38-42°C.	Maintained temperature within 38-42°C.
EMS Mode
Muscle Stimulation	Equivalent to Evolve System with T3 Applicator (K210877) for preventing/retarding disuse atrophy, increasing local blood circulation, muscle re-education, and maintaining/increasing range of motion.	Specific performance metrics not provided, but asserted to be substantially equivalent and conform to design requirements.
Burst Characteristics	Capable of stimulating muscle for at least one second per burst and providing at least one second of muscle relaxation between successive pulse bursts.	Provides muscle stimulation for 5 seconds per burst and muscle relaxation for 1 second (matching FDA guidance requirements).
General Safety & Performance
Electrical Safety	Compliance with IEC 60601-1 standard.	Full electrical safety testing done in compliance with IEC 60601-1; satisfactory results.
Electromagnetic Compatibility (EMC)	Compliance with IEC 60601-1-2 standard (emissions and immunity).	EMC testing done for emissions and immunity with IEC 60601-1-2; satisfactory results.
Biocompatibility	Compliance with ISO 10993-1 standard.	Samples of tissue contacting probes tested for cytotoxicity, sensitization, and intracutaneous reactivity; found to comply.
Software Assessment	Compliance with FDA software validation guidelines (Levels of Concern, User & System Requirements, Hazard Analysis, Software Requirements, Architectural Design, Software Validation & Testing).	Software features assessed, and all aspects addressed; satisfactory results.
Usability and Risk Management	Verification of user interface, safety features, and satisfactory performance using worse-case assumptions.	Usability and Risk Management assessments done; satisfactory results.

Study Details:

Sample sizes used for the test set and the data provenance:
- Test Set (Human Being Testing): The "tissue temperature elevation study" for the RF mode was conducted on "three different people on three body parts."
- Data Provenance: Not explicitly stated, but given the company (SWIMS America Corp, White Plains, NY), it's likely US-based or conducted to US regulatory standards. The study type is prospective as it involved actual testing on human subjects for the purpose of demonstrating performance.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not specify the number or qualifications of experts involved in establishing ground truth for the "human being testing" or any other performance studies. The ground truth for the human testing appears to be the directly measured skin and room temperatures and the clinical observation of whether therapeutic temperatures were maintained.
Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- The document does not provide information on any adjudication methods. The performance testing described (electrical safety, EMC, biocompatibility, software validation, human temperature study) likely involves objective measurements against predefined criteria/standards rather than subjective assessments requiring adjudication.
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:
- No, an MRMC comparative effectiveness study was not done. This device is a powered muscle stimulator/RF heating device, not an image analysis AI device that would typically involve human "readers" or AI assistance for diagnostic tasks.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- This question is not directly applicable as the device is a therapeutic physical medicine device, not an algorithm-only diagnostic or analytical tool. Its performance is inherent in its physical outputs (RF heating, EMS signals) as applied to a patient, rather than an "algorithm-only" output in the sense of an AI diagnostic model. However, the performance parameters (e.g., RF frequency, output power, EMS specifications) are outputs of the device's internal algorithms and hardware configurations, and these were assessed in the various safety and performance tests.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the RF mode's topical heating performance, the ground truth was direct physiological measurement (skin and room temperatures) against a defined therapeutic range (38-42°C).
- For electrical safety, EMC, and biocompatibility, the ground truth was adherence to established international standards (IEC 60601-1, IEC 60601-1-2, ISO 10993-1), verified through objective testing.
- For software assessment, the ground truth was compliance with FDA software validation guidelines.
- For usability and risk management, the ground truth was adherence to predefined worst-case assumptions and risk analysis principles.
- For the EMS mode, the ground truth for parameters like burst characteristics was compliance with FDA Powered Muscle Stimulator Guidance.
The sample size for the training set:
- This information is not applicable/provided as this is a medical device clearance, not an AI/machine learning model where "training sets" are explicitly discussed. The device's design and operation are based on engineering principles and regulatory standards, not on a machine learning training process.
How the ground truth for the training set was established:
- Not applicable, as there is no "training set" in the context of this device's development as described. The device's design and verification relied on established engineering standards, predicate device characteristics, and performance testing data.

Summary

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Image /page/0/Picture/0 description: The image contains the logos of the Department of Health & Human Services and the Food and Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo includes the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue text.

September 14, 2023

SWIMS America Corp Matthieu Commeau Managing Director 1133 Westchester Avenue Suite N 220 White Plains, New York 10604

Re: K230167

Trade/Device Name: BACK 4 Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF. PBX Dated: August 17, 2023 Received: August 17, 2023

Dear Matthieu Commeau:

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 (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 located 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.

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

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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 803) for devices or postmarketing safety reporting (21 CFR 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 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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,

Jitendra V. Virani -S

CDR Jitendra Virani, MS, MBA Assistant Director DHT5B: Division of Neuromodulation and Physical Medicine Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Ouality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K230167

Device Name BACK 4

Indications for Use (Describe)

The BACK 4 device employs RF technology or EMS technology for the treatment of selected medical conditions.

The BACK 4 device in EMS mode is intended for:

*Prevention or retardation of disuse atrophy
*Increasing local blood circulation

*Muscle re-education

*Maintaining or increasing range of motion.

The RF treatment mode and EMS mode should not be used in combination or sequentially.

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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510(k) Premarket Notification SWIMS America Corp K230167 Section 1.5

510(k) Summary

Date : 09/13/2023

1.	Submitted By:	SWIMS America Corp1133 Westchester Avenue Suite N 220White Plains, NY 10604Tel. 917-371-7388
2.	Contact Person :	Mr. Matthieu COMMEAUManaging Director of SWIMS America Corp1133 Westchester Avenue Suite N 220White Plains, NY 10604Tel. 917-371-7388Email : mat@winback.com
3.	Common Name:	BACK4 Massager, Radiofrequency Induced Heat therapy andElectrostimulation device
4.	Trade Name :	BACK 4
5.	Regulation Number:	21 CFR 890.5850
6.	Regulation Name:	Powered Muscle Stimulator
7.	Device Product Codes:	IPF, PBX
8.	Regulatory Class:	II
9.	Predicate Devices:	Primary Predicate Device: BACK3 COLOR, K214090Secondary Predicate Device: Evolve System with the T3Applicator, K210877

Description:

The product can also employ EMS technology. It generates a 4kHz or 1.5kHz electrostimulation signal (modulated at a frequency set between 2Hz and 200Hz).

The two RF and EMS technologies should not be used in combination or sequentially.

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An Emergency stop button feature allows the patient to shut down the unit in the event of any discomfort.

Intended Use:

The BACK 4 device employs RF technology or EMS technology for the treatment of selected medical conditions.

The BACK 4 device in EMS mode is intended for:

*Prevention or retardation of disuse atrophy

*Increasing local blood circulation

*Muscle re-education

*Maintaining or increasing range of motion.

The RF treatment mode and EMS mode should not be used in combination or sequentially.

Substantial Equivalence/Technological Characteristics:

The BACK 4 device is substantially equivalent to the following primary and secondary devices for the technology RF and EMS accordingly.

Device	Manufacturer	510(k) No.	Technical characteristics similar to the Subject device
Primary device
BACK3 COLORProduct codes: PBX	Daeyang Medical	K214090 (SWIMS America Corp)	RF technology (300kHz-1MHz)
Secondary device
Evolve System with the T3 ApplicatorProduct codes : IPF, PBX, GZJ	InMode Ltd.	K210877	EMS technology signals

A Primary predicate device (RF technology)

The BACK 4 device is substantially equivalent to the BACK3 COLOR device from SWIMS America Corp which was cleared under premarket notification K214090. Both devices are cart mounted consoles with electrode accessories capable of operation in monopolar and multipolar modes in the range of 300kHz to 1MHz radiofrequency.

Both devices operate in the same treatment range and feature intensity adjustments from 0 to 100%. Electrical safety and biocompatibility have been established for both devices. No direct comparison was made since there are no significant differences in operation and test results indicate identical safety.

> Secondary predicate device (EMS technology)

The BACK 4 device shares also the same intended use and Product codes (PBX, IPF) as the FDA-Cleared Evolve System with the T3 Applicator (K210877). Both devices are also designed to deliver electro-muscle stimulation (EMS) for the treatment of different body areas for various medical

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applications. These devices have the same range of frequencies (Subject Device: 2-200 Hz; Secondary Predicate: 3-200 Hz).

Indeed, both devices have specifications in common:

A Main Line Frequency (nominal): 50-60 Hz
Input Voltage (nominal): 100 240 VAC. A

Please note that the Subject device does not follow the Product code GZJ, which the secondary predicate does follow. That is why some intended uses linked to this Product Code are not found in the intended use of the Subject device: Symptomatic relief and management of chronic, intractable postsurgical acute pain.

These minor differences in technical specifications should not alter the device safety and effectiveness. Furthermore, the Subject device had underwent the required performance testing and validation testing and demonstrates its conformance with device design requirements and with applicable standards.

The safety features and compliance with safety standards of the subject device are similar to the safety features and compliance with safety standards of the predicate devices. All user-contacting materials were tested for biocompatibility and found to comply with the ISO 10993-1 standard. Furthermore, the design and development phases of the subject device were validated throughout a set of performance tests, including software validation testing, electrical and mechanical safety testing according to IEC 60601-1 standard, electromagnetic compatibility testing according to IEC 60601-1-2 standard, safety and essential performance of nerve and muscle stimulators testing according to IEC 60601- 2-10 standard.

All in all, these performance tests demonstrated that the device specifications meet the system requirements and do not raise new safety or effectiveness concerns.

Consequently, it can be concluded that the BACK 4 is substantially equivalent to its predicate device and can be sold in the US market.

The table below summarizes the equivalence of the devices.

Predicate Device Comparison Table

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SWIMS America CorpK230167
Element ofComparison	510(k) Device:BACK 4	Primary Predicate Device:BACK3 COLORK214090	Secondary Predicate Device:Evolve System with the T3ApplicatorK210877	Explanation of Differences
Regulation andProduct ClassificationCodes	21 CFR 890.5850 (IPF)21 CFR 878.4400 (PBX)	21 CFR 878.4400 (PBX)	21 CFR 890.5850 (IPF)21 CFR 878.4400 (PBX)21 CFR 882.5890 (GZJ)	The BACK 4 device follows the same Productcodes as the two predicate devices: PBX, IPF.However, BACK 4 does not use the code GZJ-Transcutaneous electrical nerve stimulator forpain relief. Therefore, BACK 4 does not havethe indications for use of the GZJ Product Code.This does not raise new questions of safety andeffectiveness.
Prescription/OTC	Prescription	Prescription	Prescription	Identical
Indications for Use	The BACK 4 device employs RFtechnology or EMS technology for thetreatment of selected medicalconditions.PBX code: The BACK 4 device in RFmode is intended to provide topicalheating for the purpose of elevatingtissue temperature for the treatment ofselected medical conditions such asrelief of pain, muscle spasms, andincrease in local circulation.The BACK 4 massage device isintended to provide a temporaryreduction in the appearance of cellulite.IPF code:The BACK 4 device in EMS mode isintended for:Prevention or retardation of disuseatrophyIncreasing local blood circulationMuscle re-educationMaintaining or increasing range ofmotion.	PBX code: The BACK3 COLORdevice is intended to provide topicalheating for the purpose of elevatingtissue temperature for the treatmentof selected medical conditions suchas relief of pain, muscle spasms, andincrease in local circulation.The BACK3 COLOR massagedevice is intended to provide atemporary reduction in theappearance of cellulite.	The Evolve System with the T3Applicator employs RFtechnology or EMS-TENStechnology for the treatment ofselected medical conditions.PBX code:The T3 Applicator in RF modeis intended for the temporaryrelief of minor muscles achesand pain, temporary relief ofmuscle spasm, and temporaryimprovement of local bloodcirculation.IPF code:The T3 Applicator in EMSmode is intended for:Relaxation of muscle spasmsPrevention or retardation ofdisuse atrophyIncreasing local bloodcirculationMuscle re-education*Maintaining or increasingrange of motion	The BACK 4 device shares the same intendedfor use as BACK3 COLOR and Evolve Systemfor the RF technology (PBX code).Also, the BACK 4 device has less indicationsfor use than Evolve System with the T3Applicator for EMS-TENS modes.Therefore, the BACK 4 device does not havenew indications for use compared to the twopredicate devices for RF and EMStechnologies. This does not raise new questionsof safety and effectiveness.

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510(k) Premarket Notification SWIMS America Corp K230167 The RF treatment mode and EMS mode Immediate post-surgical stimulation of calf muscles to should not be used in combination or prevent venous thrombosis. sequentially. GZJ code: The T3 Applicator in TENS mode is intended for: Symptomatic and management of chronic, intractable pain Post-surgical acute pain Post-trauma acute pain. The RF treatment mode and EMS/TENS mode should not be used in in combination or sequentially. Hospital or Clinic setting Environment Used Hospital or Clinic setting Hospital or Clinic setting Identical IEC 60601-1: General requirements IEC 60601-1: General requirements Performance IEC 60601-1: General The BACK 4 device complies to the same standards (FDA for basic safety and essential for basic safety and essential requirements for basic safety performance standards as the two predicate recognized consensus performance performance and essential performance devices, except to standards) IEC 60601-2-2 as the Subject device is not IEC 60601-1-2: General requirements IEC 60601-1-2: General IEC 60601-1-2: General intended to be used in a surgical environment for basic safety and essential requirements for basic safety and requirements for basic safety nor in an emergency. Also, the BACK 4 device performance - Collateral Standard: essential performance - Collateral and essential performance is not a life supporting device. This does not Electromagnetic disturbances -Standard: Electromagnetic Collateral Standard: raise new questions of safety and effectiveness. Requirements and tests. disturbances - Requirements and Electromagnetic disturbances tests. Requirements and tests. IEC 60601-2-10: particular IEC 60601-2-10: particular requirements for the Basic Safety and IEC 60601-2-10: particular Essential Performance of Nerve and requirements for the Basic Safety requirements for the Basic Muscle stimulators. and Essential Performance of Nerve Safety and Essential and Muscle stimulators. Performance of Nerve and IEC 60601-1-6: General requirements Muscle stimulators. for basic safety and essential IEC 60601-1-6: General performance -Collateral standard: requirements for basic safety and IEC 60601-1-6: General Usability. essential performance -Collateral requirements for basic safety standard: Usability. and essential performance -Collateral standard: Usability.

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		510(k) Premarket Notification
		SWIMS America Corp
		K230167
			EN IEC 60601-2-2 :Particularrequirements for the basic safetyand essential performance ofhigh-frequency surgicalequipment and high-frequencysurgical accessories.
Applicator Shapes	Square, rectangular and circular	Square, rectangular and circular	Rectangular	Identical to the primary predicate device.Difference in shape compared to the secondarypredicate device. However, this differencedoes not raise any new questions of safety andeffectiveness compared to the secondarypredicate device. The biocompatibility testingand usability attest of the safety of theseaccessories.
Infrared Light	No	No	No	Identical
Vacuum (suction)	No	No	No	Identical
Applied energy	RF/EMS	RF	RF/EMS-TENS	The BACK 4 device has the same RFtechnological characteristics as the primarypredicate device.The subject device can apply the same energyEMS as the secondary predicate device.However, the BACK 4 does not use GZJ as thesecondary predicate device does. So, thesubject device does not have TENS energy.This does not raise new questions of safety andeffectiveness.
Power source	Main line frequency (nominal): 50-60Hz.Input Voltage (nominal):100-240VAC.Input current (rms): 1.25Aac@240Vac and 3Aac @ 100Vac.	Main line frequency (nominal): 50-60Hz.Input Voltage (nominal):100-240VAC.Input current (rms): 1.25Aac@240Vac and 3Aac @ 100Vac.	Main line frequency (nominal):50-60Hz.Input Voltage (nominal): 100-240VAC.Input current (rms): 4A.	Power source characteristics are identical to theprimary predicate device.The power source characteristics are differentto those of the secondary predicate device. Themain line frequency and input voltage aresimilar, except for the input current. However,this difference does not raise new safety andeffectiveness questions as electrical safetytesting has been performed following state ofthe art standards.

RF Type	Multipolar/Unipolar	Multipolar/Unipolar	Multipolar/Unipolar	Identical
RF Frequency	300kHz – 1MHz	300kHz – 1MHz	1MHz	Identical to the Primary predicate device for RFtechnology.The RF frequency of the secondary device fallswithin range of the subject device.This difference does not raise any newquestions of safety and effectiveness comparedto the secondary predicate device.
Maximum RF outputPower	300W	300W	75W	Identical to the primary predicate device.Different from the secondary predicate device.However, this difference does not raise newquestions of safety and effectiveness. RF outputpower has already been cleared with theprimary predicate device.
Electrical type	Type BF	Type BF	Type BF	Identical
EMS outputspecifications;waveform	Biphasic with symmetrical waveform	N.A	SymmetricalBiphasic waveform	Identical
EMS Frequency	2 to 200Hz	N.A	3 to 200 Hz	Not identical.The EMS frequency range of the subject devicehas minor difference to the secondary predicatedevice.This difference does not raise any newquestions of safety and effectiveness comparedto the secondary predicate device.This characteristic does not apply to theprimary predicate device.
Patient LeakageCurrent -NormalCondition (uA)	<50uA patient leakage	N.A	<100uA patient leakage	Not identical.Patient leakage current range has minordifference to the patient leakage current rangeof the secondary predicate device.This difference does not raise any newquestions of safety and effectiveness comparedto the secondary predicate device.This characteristic does not apply to theprimary predicate device.
Patient LeakageCurrent-Single Faultcondition (uA)	<300uA line leakage	N.A	<300uA line leakage	Identical to the secondary predicate device.This characteristic does not apply to theprimary predicate device.
Number of Outputchannels	3	3	6	Not identical.The BACK 4 device has less output channelsthan the secondary predicate device. This doesnot raise new questions of safety andeffectiveness.
Console	Console, including a power supplyunit, controller, and user interfaceincluding a LCD touch screen.	Console, including a power supplyunit, controller, and user interfaceincluding a LCD touch screen.	Console, including a powersupply unit, controller, and userinterface including a LCD touchscreen.	Identical
Software control	Yes	Yes	Yes	Identical
Indicator Display	On/Off statusVoltage/current level	On/Off statusVoltage/current level	On/Off statusVoltage/current level	Identical
Battery	No	No	No	Identical
Timer Range(minutes)	0-60 (minutes)	0-60 (minutes)	0-60 (minutes)	Identical
Accessories provided	TECAR X handset	/	T3 Applicator:	Comparison with the primary predicate device:
with the device(diameter of the	RET Bracelet	RET Bracelet	Up to 6 units connected to theconsole via 6 designed cablesand 6 designated connectionport.Size of the applicator : 67.3mmL x 54.3mm D	*Addition/deletion of some accessories for thesubject device compared to the primarypredicatedevice: additionalaccessoriesprovided with the subject device are indicatedin blue.The addition of these accessories does not raisenew questions of safety and effectiveness of thesubject device.These accessories have been added to facilitatethe treatment of the therapist depending on thearea to be treated.These accessories have however the sameutility, the same intended use as the primarypredicate device and the associated modes areidentical to those of the predicate (CET, RET,etc.).
electrodes in	Neutral return plate	Neutral plate
millimeters)	Neutral handle	/
	RET electrodes (40, 60, 70mm) [1]	RET electrodes (40, 60, 70mm)
	Convex RET electrodes (25, 40mm) [1]	Convex RET electrode (25mm)
	CET electrodes (40, 60, 70mm)	CET electrodes (40, 60, 70mm)
	Convex CET electrodes (35, 40,60mm)	Convex CET electrode (35, 60mm)
	Hi-RET electrode	TECAR 6.0 HandpieceTECAR 6.0 Tip (M)
	Multipolar electrode S	3-Polar applicator Face
	Multipolar electrode L	3-Polar applicator Body
	RET Fixed Pad (120mm*60mm) [1]	Resistive Fix Pad
	Neutral Fixed Pad	Neutral Fix Pad		*Change of some accessory denominations:Some accessories have a new name but stay the
	TECAR mobile handle	/		same as for the predicate (same design, sameintended use, same contact material).
	Neutral generic cable	/
	RET/CET generic cable	Active cable for CET electrodesActive cable for RET electrodes		Not all the listed accessories of the subjectdevice can be connected as the same time, as
	RET snap cable	/		there are only 3 channels on the device. It is the
	CET Extender	/		same for the primary predicate device.
	RET Extender	/		[1] These accessories can be used with the EMSmode.
	Emergency stop button	Safety Switch
	Power cord	Alimentation cable		Comparison with the secondary predicate
	Essential conductive Cream	/		device:
	Fascia Blade	Physio Blade and Connector		The secondary predicate device has moreaccessories connected during the treatment. It
	/	CET handpiece		can have up to 6 accessories for RF or EMStechnology.Due to this configuration, it is less risky for thepatient to be treated with less pieces. Thedifference doesn't raise new questions of safetyand effectiveness.The size of the subject device electrodes usedfor EMS mode is different from the size of thesecondary predicate device applicator.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.
	/	RET handpiece
	/	Thai CET Electrode (70mm)
	/	Protect Ring (50, 70, 80mm)
	/	Capacitive Fix Pad
	/	Flex Pack
	/	Finger Handpiece
Modes	/	Double Cable
	/	CET straight
		/
	CET SOFT	CET	RF	Comparison with the primary predicate device:Change of some Mode's names: some modeshave a new name but are the same (same
	CET DEEP	CET DEEP		intended use and frequencies).
		SWIMS America Corp
		K230167
	RET	RET		This difference does not raise new questions of safety and effectiveness.
	RET + Hi-TENS	DEEP RET		The Hi-EMS mode does not apply to the primary predicate device.
	Hi-TENS	PULSE		Comparison with the secondary predicate device:Both have the EMS mode. The only difference is the marketing name of it.
	MIX	FOCUS 3-POLARBODY 3-POLAR		Electrical safety and EMC testing have been
	/	FRACTAL		performed for the subject device. This difference does not raise new questions of safety and effectiveness.
	Hi-EMS	/	EMS
Functions	LOW	MINI	N.A	The names of the functions are the same as
	MEDIUM	MEDIUM		those of the primary predicate device, except
	BOOST	BOOST		for LOW function; The MINI function was
	DYNAMIC	DYNAMIC		renamed by LOW. However, the technical characteristics of that LOW function are
	SWAP	SWAP		identical to those of the MINI function.
	STATIC	STATIC
Design	The BACK 4 device consists of anAC/DC power supply unit, controller,2 RF generators and user interfaceincluding an LCD touch screen.The delivery of the RF/electricalenergy is controlled by a On/Offbutton positioned on the front panel.The system supports the followingcomponents:• LCD display touch screen• Audio loudspeaker	The BACK3 COLOR consists of anAC/DC power supply unit,controller, 2 RF generators and userinterface including an LCD touchscreen.The delivery of the RF is controlledby a On/Off button positioned onthe front panel.The system supports the followingcomponents:• LCD display touch screen• Audio loudspeaker	The EVOLVE system with T3Applicator consists of anAC/DC power supply unit,controller, 2 RF generators anduser interface including anLCD touch screen.The delivery of theRF/electrical energy iscontrolled by a Start/Stopbutton positioned on the frontpanel.	The subject device does not have the same dimensions and design than thee predicate devices.However, the screen of the BACK 4 device has the same size as the cleared device BACK 3 COLOR.Finger selection on screen for the three devices.However, the difference doesn't raise new questions of safety and effectiveness.
	• 100-240 VAC power supply• Controller (GMU card)• 2 RF generatorsThe system operates while connectedto the accessories (electrodes) in RFmode or in EMS mode.	• 100-240 VAC powersupply• Controller• 2 RF generators	The system supports thefollowing components:• LCD display touchscreen• Audio loudspeaker• 100-240V• Controller• 2 RF generators
		SWIMS America CorpK230167
		The system operates whileconnected to the accessories(electrodes) in RF mode.	The system operates whileconnected to the applicators inRF mode or in EMS-TENSmode.
Dimension console(height x width xdepth) in millimeters	403.6x379.0x190.5	148x306x358	100x460x460	Not identical.However, the difference doesn't raise newquestions of safety and effectiveness.The devices are not supposed to be moved.
Weight (kg)	6 kg	5 kg	33 kg	Not identical.The subject device is less heavy than thepredicate devices. That difference does notgenerate a safety and effectiveness issue.
Target temperatures	38-42°C	38-42°C	NA	Identical to the primary predicate device.
Treatment areas	All body, external part except eyes,mouth, heart, mucosa parts and brainarea	All body, external part except eyes,mouth, heart, mucosa parts andbrain area	Body parts requiring treatmentas specified in the indicationfor use	Identical
Safety features	Emergency stop button	Emergency stop button	System in STOP state level at60 minutes.	Identical
Sterility	N.A	N.A	N.A	N.A
EMS Output Mode
Waveform	Biphasic with symmetrical waveform	N.A	SymmetricalBiphasic waveform	Identical
Shape	Sinusoidal	N.A	Rectangular	Not identical.The subject device and the secondarypredicate device are capable of musclestimulation.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new question ofsafety and effectiveness.
				This characteristic does not apply to theprimary predicate device.
Maximum OutputVoltage (Vpeak)(+/-10%)	21.8 V @ 500 Ω32.3 V @ 2 k Ω36.6 V @ 10 k Ω	N.A	30 V @ 500 Ω54 V @ 2 k Ω54 V @ 10 k Ω	Not identical.The subject device provides a lower maximumoutput voltage than the secondary predicatedevice.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.
Maximum OutputCurrent (mA)(+/- 10%)	43.6 mA @ 500 Ω16.2 mA @ 2 k Ω3.7 mA @ 10 k Ω	N.A	60 mA @ 500 Ω27 mA @ 2 k Ω5.4 mA @ 10 k Ω	Not identical.The subject device provides a lower maximumoutput current than the secondary predicatedevice.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.
SWIMS America CorpK230167
Pulse Width (µsec)	Radial mode: 250µsecFocal mode : 250µsec	N.A	20 to 400µsec	Not identical.Radial mode:The pulse width of the subject device is withinthe range of the pulse width of the secondarypredicate device.This difference does not raise any newquestions of safety and effectiveness comparedto the secondary predicate device.This characteristic does not apply to theprimary predicate device.Focal mode:The pulse width of the subject device is withinthe range of the pulse width of the secondarypredicate device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.
Frequency (Hz)	2 to 200Hz	N.A	3 to 200 Hz	Not identical.The EMS frequency range of the subject devicehas minor difference to the secondary predicatedevice.This difference does not raise any newquestions of safety and effectiveness comparedto the secondary predicate device.This characteristic does not apply to theprimary predicate device.
Net Charge @ 500ohms (microC/pulse)	0	N.A	0	Identical to the secondary predicate device.This characteristic does not apply to theprimary predicate device.
			SWIMS America CorpK230167
Maximum PhaseCharge (microC)	28.8 microC @ 500 Ω	N.A	24 microC @ 500 Ω	Not identical.The subject device provides a higher maximumphase charge than the secondary predicatedevice.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.
Maximum CurrentDensity (RMS),(mA/cm²)(Using smallestelectrode conductivesurface area)	1.6 (mA/cm²)Surface = 12.6cm²	N.A	0.74 (mA/cm²)Surface = 6.46cm²	Not identical.The subject device provides a higher maximumcurrent density than the secondary predicatedevice.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.

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BACK 4 510(k)

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510(k) Premarket NotificationSWIMS America CorpK230167
Maximum PowerDensity, (mW/cm²)(Using smallestelectrode conductivesurface area)	15.7 (mW/cm²)	N.A	22.2 (mW/cm²)
			Not identical.The subject device provides a lower maximumpower density than the secondary predicatedevice.Electrical safety testing and EMC testing havebeen performed for the subject device.Usability and risk analysis have also beenperformed to support proof of safety andeffectiveness of the subject device.This difference does not raise new questions ofsafety and effectiveness compared to thesecondary predicate device.This characteristic does not apply to theprimary predicate device.Moreover, the maximum power density isunder the limit according to Section 3 ofAttachment II (Output Waveforms) of FDA'sPowered Muscle Stimulator Guidance(https://www.fda.gov/media/71804/download).

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510(k) Premarket NotificationSWIMS America CorpK230167
Burst Mode (i.e., pulse trains)a. Pulses per burstb. Bursts per secondc. Burst duration (seconds)d. Duty Cycle [Line (b) x Line (c)]	Yes,a. 2-200b. 1c. 5 secd. Time on/off	N.A	Yes,a. 3-200b. 1c. 1-60 secd. Time on/off	Not identical.Pulses per burst:The subject device has minor difference in pulses per bust range compared to the secondary predicate device. This difference does not raise any additional questions of safety and effectiveness compared to the secondary predicate device.This characteristic does not apply to the primary predicate device.Burst duration:The subject device has a different burst duration than the secondary predicate device.However, the burst duration of the subject device does not fall outside of the burst duration scope of the secondary predicate device.Electrical safety testing and EMC testing have been performed for the subject device.Usability and risk analysis have also been performed to support proof of safety and effectiveness of the subject device.This difference does not raise new questions of safety and effectiveness compared to the secondary predicate device.This characteristic does not apply to the primary predicate device.Moreover, according to Section 3 of Attachment II (Output Waveforms) of FDA'S Powered Muscle Stimulator Guidance, for effectiveness in achieving repeated muscle contractions, powered muscle stimulators typically are capable of stimulating muscle for at least one second per burst, and are capable of providing at least one second of muscle relaxation between successive pulse bursts.Regarding the burst characteristics, our subject device provides a muscle stimulation for 5 seconds per burst and a muscle relaxation for 1
ON Time (seconds)	5 sec (6 sec period)	N.A	1-60 sec	Not identical.The subject device does not fall outside of therange of the secondary predicate device. Thisdifference does not raise new question of safetyand effectiveness compared to the secondarypredicate device.This characteristic does not apply to theprimary predicate device.
OFF Time (seconds)	1 sec (6 sec period)	N.A	1-60 sec	Not identical.The subject device does not fall outside of therange of the secondary predicate device. Thisdifference does not raise new question of safetyand effectiveness compared to the secondarypredicate device.This characteristic does not apply to theprimary predicate device.
Treatment time(minutes)	Up to 60 minutes	N.A	Up to 60 minutes	Identical

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Summary of Testing:

The technological characteristics of the BACK 4 System has of electical safety, performance, biocompatbility, software and usability.

The following testing has been conducted with satisfactory results:

. B ACK4 Usability and Risk Management Usability and Risk Management assessments were done using worse-case assumptions to verify user interface, safety features and satisfactory performance.
Biocompatibility: Samples of the tissue contacting probes were tested for cytotoxicity, sensitization and intracutaneous reactivity, .
Software Assessment: Software features were assessed in accordance with FDA software validation guidelines. Levels of Concern, User & System . Requirements, Hazard Analysis, Software Requirements, Architectural Design, Software Validation & Testing were all addressed.
Electromagnetic Compatibility: EMC testing was done to evaluate emissions and immunity to electromage with IEC 60601-1-. 2.
Electrical Safety: Full electrical safety testing was done in compliance with IEC 60601-1. .

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. Human being testing: a tissue temperature elevation study was conducted to demonstrate ability of all applicators of the RF mode of subject device to maintain therapeutic temperature on the human skin. The study was conduct on three different people on three body parts with all device operation modes and at the lowest and highest power settings. The skin and room temperatures were measured.

Conclusion:

Based on the comparison to the predicate devices and on the nevels demonstrating that the BACK 4 is as safe and effective as the primary and secondary predicate devices, the BACK3 COLOR FDA cleared under 510(k) K214090, and the Evolve System with the T3 Applicator cleared under 510(k) K210877 and therefore the subject device is substantially equivalent to these predicate devices.

Regulation Number and Section

§ 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).