The Buttock Muscle Stimulator, model WL-2413E, is intended for use by healthy persons to apply transcutaneous electrical muscle stimulation(EMS) through skin contact electrode for the purpose of improvement of muscle tone of the buttocks muscles.

Device Description

The Buttock Muscle Stimulator, model WL-2413E, is a two channel battery operated muscle stimulation system specifically designed to exercise the buttocks' muscle. The device comprises mainly the electronic stimulator module which generates the required stimulation signals. The Buttock Muscle Stimulator, model WL-2413E, comprises a short with silicon pad electrodes which connect the signals from the stimulator to the skin. The electrodes are placed on the inner surface of the accessories. The product is supplied with a 510(K) cleared conductive gel, a user's manual, 3AAA batteries, 2 lead wires and a storage bag. The required power of the device is derived from 3 batteries located in a compartment protected by a removable battery cover. The electrodes are in the inner surface of the shorts which is worn as shown on the picture of user manual. There is no current passed from side to side. The user cannot access the wiring or connectors within the shorts.

AI/ML Overview

The provided 510(k) summary for the Buttock Muscle Stimulator, model WL-2413E, does not contain information about acceptance criteria or a study that specifically proves the device meets those criteria, particularly in the context of typical AI/medical imaging device submissions.

This submission is for a medical device that applies transcutaneous electrical muscle stimulation (EMS) and is seeking substantial equivalence to a predicate device. The "study" referenced in this document is a comparison of technical characteristics to demonstrate substantial equivalence, rather than a clinical trial or performance study with acceptance criteria often seen in AI device submissions.

Therefore, most of the requested information cannot be extracted from this document as it pertains to a different type of device and regulatory submission.

However, I can provide what is available regarding the comparison to the predicate device, which serves as the basis for its clearance.

1. Table of "Acceptance Criteria" (Comparison of Performance/Characteristics to Predicate) and Reported Device Performance

Instead of formal "acceptance criteria" and "reported device performance" in the sense of a clinical outcome study, this document focuses on demonstrating that the new device's technical characteristics are "substantially equivalent" to a legally marketed predicate device. The performance is indirectly compared by showing that critical parameters are either identical or within acceptable ranges when compared to the predicate.

Characteristic	Acceptance Criteria (Predicate Device)	Reported Device Performance (New Device: WL-2413E)
General Features
Prescription or OTC	OTC	Same (OTC)
Indication for use	Purpose of improvement of muscle tone of the buttocks muscles	Same
FDA product code	NGX	Same (NGX)
Manufacturer	SPORT-ELECT	Well-Life
Unit Characteristics & Output
Waveform	Biphasic	Biphasic
Shape	Rectangular	Rectangular
Max Output Voltage @500Ω	31.2V	40.8V
Max Output Voltage @2KΩ	66.0V	70.0V
Max Output Voltage @10KΩ	66.0V	106.0V
Max Output Current @500Ω	62.4mA	81.6mA
Max Output Current @2KΩ	33.0mA	35.0mA
Max Output Current @10KΩ	6.6mA	10.6mA
Duration of primary phase (usec)	200 Max	300 Max
Pulse Duration (usec)	540 Max	720 Max
Frequency (Hz)	70 Max	70 Max
Symmetrical phases?	Yes	Yes
Power Source	1.5Vx3 (AAA Size)	1.5Vx3 (AAA Size)
Patient Leakage Current	Under 0.1 uA (Normal), Under 0.5 uA (Single Fault)	Under 0.1 uA (Normal), Under 0.5 uA (Single Fault)
Number of Output Modes	4	4
Number of Output Channels	Synchronous, Output Coil	Synchronous, Output Coil
Regulated Current or Voltage?	Voltage	Voltage
Software/Firmware/Microprocessor	Yes	Yes
Automatic Overload Trip?	No	No
Automatic No-Load Trip?	Yes	Yes
Automatic Shut Off?	Yes	Yes
User Override control?	No	No
Timer Range (Minutes)	20-40	20-40
Compliance with Voluntary Stds?	IEC 60601-2-10	IEC 60601-2-10
Compliance with 21 CFR 898?	Yes	Yes
Weight (g)	171.6	80
Dimensions (mm.) [W x H x D]	87×43×69	64×90×20
Housing Materials	ABS	ABS
Net charge	0	0
Max. phase charge	14 uc	24 uc
Max. current Density	0.0784 mA/cm²	0.0997 mA/cm²
Max. Average current @500Ω	38.43mA	38.644mA
Max. Average current @2KΩ	14.892mA	16.907 mA
Max. Average current @10KΩ	4.996mA	5.120 mA
Max. Power Density	0.00274 Watts/cm²	0.00399 Watts/cm²
Burst Mode	Yes	Yes

2. Sample size used for the test set and the data provenance:

Sample Size: Not applicable. This submission relies on comparing technical specifications and safety standards, not a clinical test set with human subjects.
Data Provenance: Not applicable in the context of a clinical test set. The data provenance relates to the technical specifications of the predicate device (from its 510(k) K092142) and the technical specifications of the new device derived from engineering tests and calculations.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

Not applicable. There was no "test set" and no "ground truth" in the clinical sense in this document. The determination of "substantial equivalence" is made by the FDA based on the presented technical comparisons and compliance with relevant standards.

4. Adjudication method for the test set:

Not applicable. No clinical test set with adjudicated results was used.

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. This is not an AI diagnostic device.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Not applicable. This is not an AI diagnostic device.

7. The type of ground truth used:

Not applicable in a clinical sense. The "ground truth" for this submission is the established technical characteristics and safety profile of the legally marketed predicate device and the adherence to relevant international standards (e.g., IEC 60601-2-10).

8. The sample size for the training set:

Not applicable. This is not an AI/machine learning device that requires a training set.

9. How the ground truth for the training set was established:

Not applicable.

Summary

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510(K) Summary

The assigned 510(k) number is: K123075

Submitter's Identifications: 1.

Well Life Healthcare Limited 1F., No. 16, Lane 454, Jungjeng Road, Yunghe City, Taipei County 234, Taiwan, ROC

Contact: Jenny Hsieh Telephone: + 886 2 2928 2112

Date of Summary Preparation: May 25, 2013

2. Name of the Device:

Trade/Device Name: Buttock Muscle Stimulator, model: WL-2413E. Regulation Number: 21 CFR 890.5850 Requlation Name: Power muscle stimulator. Regulatory Class: II Product Code: NGX

3. Information of the 510(k) Cleared Device (Predicate Device):

SPORT-ELEC models Body Control System "BS"( K092142)

Device Description: 4.

The Buttock Muscle Stimulator, model WL-2413E, comprises a short with silicon pad electrodes which connect the signals from the stimulator to the skin. The electrodes are placed on the inner surface of the accessories. The product is supplied with a 510(K) cleared conductive gel, a user's manual, 3AAA batteries, 2 lead wires and a storage bag.

The required power of the device is derived from 3 batteries located in a compartment protected by a removable battery cover. The electrodes are in the inner surface of the shorts which is worn as shown on the picture of user manual. There is no current passed from side to side. The user cannot access the wiring or connectors within the shorts.

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5. Intended Use:

Discussion of Non-Clinical Tests Performed Determination of Substantial Equivalence are റ. as follows:

Compliance to applicable voluntary standards includes IEC 60601-2-10, as well as IEC 60601-1, and IEC 60601-1-2 requirement.

In addition to the compliance of voluntary standards, the software verification has been carried out according to the FDA software guidance.

Discussion: The Compliance to applicable voluntary standards as above mentioned indicates that the new device in this submission used the same standards as that of predicate device in addition to the software validation standard. For our new device, the software validation was prepared according to FDA guidance, however the predicate device used IEC 60601-1-4 to prepare their software validation report. For this difference we believe that we used more adequate reference tool to prepare software validation report than the predicate device. Therefore, we consider that the compliance of standards included in our submission is adequate for the determination of substantial equivalence.

7. Comparison of Significant device features

ComparisonFeatures	Models to be Compared
Model	SPORT-ELEC Body Control System"BS"	WL-2413E
510(K) No.	K092142	K123075
Prescription or OTC	OTC	Same
Indication for use	intended for use by healthy persons toapply transcutaneous electrical musclestimulation(EMS) through skin contactelectrode for the purpose of improvementof muscle tone of the buttocks muscles	Same
FDA product code	NGX	Same
Electrode Used	Self Adhesive Electrode( 5 X 5 cm)	K082065, Silicon Pad Electrode( 7.0 cm diameter)
Manufacturer	SPORT-ELECT	Well-Life

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8. Comparison of Unit Characteristics & Output Specification

Mode or Program Name	Predicate Device	New Device
Waveform (e.g., pulsed monophasic, biphasic)	Biphasic	Biphasic
Shape (e.g., rectangular, spike, rectifiedsinusoidal)	Rectangular	Rectangular
Maximum Output Voltage (volts)-(+/- 20%)	31.2V @500Ω66.0V @2KΩ66.0V @10KΩ	40.8V @500Ω70.0V @2KΩ106.0V @10KΩ
Maximum Output Current (mA)-(+/- 20%)	62.4A @500Ω33.0A @2KΩ6.6A @10KΩ	81.6mA @500Ω35.0mA @2KΩ10.6mA @10KΩ
Duration of primary phase (usec)	200 Max	300 Max
Pulse Duration (usec)	540 Max.	720 Max.
Frequency (Hz) [or Rate (pps)]	70 Max	70 Max
Formultiphasicwaveformsonly:	Symmetrical phases?Phase Duration (include units),(Stage range, if applicable),(both phases, if asymmetrical)	YesNot applicable	YesNot applicable
510(K) Number	K092142	K123075
Device Name and Model	BS	WL-2413E
Manufacturer	SPORT-ELECT	Well-Life
Power Source(s)	1.5Vx3(AAA Size)	1.5Vx3(AAA Size)
- Method of Line current Isolation- Patient Leakage Current	Type BF---	Type BF---
- Normal condition (uA)	Under 0.1	Under 0.1
- single Fault condition (uA)	Under 0.5	Under 0.5
Average DC current through electrodes whendevice is on but no pulses are being applied ( uA)	Not applicable	Not applicable
Number of Output Modes	4	4
Number of OutputChannels:	Synchronous orAlternating?Method of ChannelIsolation	SynchronousOutput Coil	SynchronousOutput Coil
Regulated Current or Regulated Voltage?	Voltage	Voltage
Software/Firmware/Microprocessor control?	Yes	Yes
Automatic Overload Trip?	No	No
Automatic No-Load Trip?	Yes	Yes
Automatic Shut Off?	Yes	Yes
User Override control?	No	No
Indicator Display:	On/Off Status?Low Battery?Voltage/CurrentLevel?	YesYesYes	YesYesYes
Timer Range (Minutes)	20-40	20-40
Compliance with Voluntary Standards?	IEC 60601-2-10	IEC 60601-2-10
Compliance with 21 CFR 898?	Yes	Yes
Weight (g) including battery	171.6	80
Dimensions (mm.) [W x H x D]	87×43×69	64×90×20
Housing Materials and construction	ABS	ABS
Pulse per burst	Same for each program	Same for each program
Burst per second	Same for each program	Same for each program
Bust duration	Same for each program	Same for each program
Duty Cycle	Same for each program	Same for each program
Method of achieving zero net charge for net	Method of achieving zero net charge/pulse	Biphasic symmetric		Biphasic symmetric	Biphasic symmetric wave for each pulse	Biphasic symmetric wave for each pulse

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Comparison feature	Model		Remarks
	SPORT-ELECT BS	WL-2413E
Net charge	0	0	Note 1
Max. phase charge	14 uc	24 uc
Max. current Density	0.0784 mA/cm²	0.0997 mA/cm²
Max. Averagecurrent	38.43mA	38.644mA
500 Ω
2K Ω	14.892mA	16.907 mA
(RMSA)
10 Ω	4.996mA	5.120 mA
Max. Power Density	0.00274 Watts/ cm²	0.00399 Watts/ cm²
Burst Mode	Yes	Yes

9. Significant output characteristics comparison table:

Note 1: Net Charge is Zero for the symmetrical stimulation biphasic wave

10. Summary for the technology comparison.

Basically the WL-2413E has the similar technological characteristics with the predicate device in the product design, material, energy source type, main program mode and the main output waveform... etc. There exist some difference in the detailed output parameters( mainly in the pulse duration and electrode sizes). Through the detailed calculation comparison of stimulation output energy for each operation mode(in particular the output current density), we found the output level in each operation mode for our WL-2413E and predicate device are very close and within the acceptable range as specified in FDA guidance. So we believe the difference in detailed output parameters does not affect the determination of substantial equivalence.

11. Conclusions

The Buttock Muscle Stimulator, model: WL-2413E have the same intended use and the similar technological characteristics as the cleared device- SPORT-ELEC models Body Control System "BS"( K092142). Moreover, verification and validation tests contained in this submission demonstrate that the difference in the submitted models could maintain the same safety and effectiveness as that of cleared device.

In the other words, those engineering difference do not: (1) affect the intended use or (2) alter the fundamental scientific technology of the device.

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Image /page/4/Picture/0 description: The image shows the logo for the Department of Health & Human Services - USA. The logo is circular, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the top half of the circle. Inside the circle is a stylized symbol that resembles a person embracing another person, or a bird in flight, composed of three curved lines.

DEPARTMENT OF HEALTH & HUMAN SERVICES

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

July 11, 2013

Well-Life Healthcare Ltd C/O Ms. Jennv Hsieh 1F. No. 16, Lane 454, Jungjeng Road Yunghe City, Taipei County, Taiwan R.O.C.

Rc: K123075

Trade/Device Name: Well-Life Buttock Muscle Stimulator. model W1.-2413E Regulation Number: 21 CFR 890.5850 Regulation Name: Powered muscle stimulator Regulatory Class: Class II Product Code: NGX Dated: June 2. 2013 Received: June 5, 2013

Dear Ms. Hsieh:

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. 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 docs 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 (sec above) into cither 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 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

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Page 2 - Ms. Jenny Hsieh

CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Small Manufacturers, International and Consumer Assistance at its tollfree number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled. "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Joyce M. Whang -S

Victor Krauthamer, Ph.D. for Acting Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): K123075

Device Name: Well-Life Buttock Muscle Stimulator, model: WL 2413E

Indications For Use:

Prescription Use (Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use × (21 CFR 801 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Joyce M. Whang -S

(Division Sign Off) Division of Neurological and Physical Medicine Devices (DNPMD)

510(k) Number _ K123075_

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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).