The Mini Patch, model: WL-2301A & WL-2301B Transcutaneous Electrical Nerve Stimulators are intended for temporary relief of pain associated with sore and aching muscles in the upper and lower extremities (arm and/or leg) due to strain from exercise or normal household and work activities.

Device Description

The Mini Patch, models WL-2301B are transcutaneous electrical nerve stimulator used for pain relief by applying an electrical current to electrodes, which are attached on the skin. The output and waveform characteristic is fixed for every model, only the intensity is adjustable.

The Mini Patch, models WL-2301A & WL-2301AB, consist mainly of two parts: the stimulus generator, electrode. The stimulus generator generates the output current specified as the input of controller. The output port transmits the output current to the electrode, which is attached to the patient's skin so as to transmit this stimulus current to the patient for pain relief.

The stimulation mode for Mini Patch is burst mode with fixed pulse rate, frequency, and fixed timer, only amplitude is adjustable. This operation way is considered the simplification from the burst mode of comparison clear model, WL-2302(K020020). Every model of Mini-TENS has its individual stimulation operation cycle.

AI/ML Overview

This 510(k) summary describes a Transcutaneous Electrical Nerve Stimulator (TENS) device, the "Mini Patch" (models WL-2301A & WL-2301B), intended for temporary pain relief. The submission focuses on demonstrating substantial equivalence to a predicate device, not on proving clinical efficacy through a new clinical effectiveness study. Therefore, many of the requested criteria (like ground truth, expert adjudication, MRMC studies, standalone performance, and training set information) are not applicable as this type of submission typically relies on engineering and performance testing to show the new device operates similarly and safely to an already cleared device.

Here's a breakdown based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

For this type of device and submission (510(k) for substantial equivalence), the "acceptance criteria" are primarily established through compliance with recognized standards and comparison to a predicate device's specifications. The study demonstrating this is a non-clinical comparison and verification/validation testing.

Acceptance Criteria (Comparison to Predicate Device WL-2407 (K091757))	Reported Device Performance (Mini Patch WL-2301A & WL-2301B)
Intended Use: Same as predicate	Same (temporary relief of pain in upper/lower extremities due to sore muscles)
Product Code: Same as predicate (NUH)	Same
Regulation Number: Same as predicate (21 CFR 882.5890)	Same
Prescription or OTC: Same as predicate (OTC)	Same
Manufacturer: Same as predicate (Well-Life)	Same
Power Source(s): Similar (Predicate: 1.5Vx3 AAA; New: 3Vx1)	3Vx1
Method of Line Current Isolation: Same as predicate (Type BF)	Same
Patient Leakage Current (Normal): Under 0.1 uA	Same (Under 0.1 uA)
Patient Leakage Current (Single Fault): Under 0.5 uA	Same (Under 0.5 uA)
Number of Output Modes: Similar (Predicate: 8; New: 3)	3
Waveform: Same as predicate (Biphasic, Rectangular)	Same
Max Output Voltage (@500Ω): Predicate: 40V; New: 30V	30V
Max Output Current (@500Ω): Predicate: 80mA; New: 60mA	60mA
Duration of Primary Phase: Predicate: 260 Max usec; New: 250 Max usec	250 Max usec
Pulse Duration: Predicate: 500.26 ms/Max.; New: 33.58 ms/Max.	33.58 ms/Max.
Frequency (Rate): Same as predicate (60 Max Hz)	Same (60 Max Hz)
Symmetrical phases? Same as predicate (No)	Same (No)
Net charge: Zero for symmetrical biphasic wave	Achieved (Zero for symmetrical biphasic wave)
Max. phase charge: Predicate: 20.8 uc; New: 15 uc	15 uc
Max. current Density: Predicate: 0.050 mA/cm²; New: 0.055 mA/cm²	0.055 mA/cm²
Max. Average Current (RMSA) (@500Ω): Predicate: 38.43mA; New: 29.394mA	29.394 mA
Max. Power Density: Predicate: 0.0020Watts/cm²; New: 0.0017Watts/cm²	0.0017Watts/cm²
Compliance with Voluntary Standards: ANSI/AAMI NS4, IEC 60601-1, IEC 60601-1-2	Same
Compliance with 21 CFR 898: Yes	Same
Software Verification: Carried out according to FDA guidance	Confirmed as carried out

The "study" that proves the device meets the acceptance criteria is the non-clinical testing, verification, and validation activities performed by the manufacturer, as summarized in sections 6, 8, and 9 of the 510(k) submission. These tests compare the new device's technical specifications and safety features against those of the predicate device and relevant voluntary standards to demonstrate that the small differences do not raise new questions of safety or effectiveness.

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

Sample Size for Test Set: Not applicable in the context of a clinical test set. The submission refers to engineering and performance verification and validation tests for the device itself, not patient data. These tests would involve multiple units of the new device to confirm consistency and adherence to specifications.
Data Provenance: Not applicable for clinical data. The data provenance is from the manufacturer's internal engineering and testing labs in Taiwan, ROC, where the device was developed and tested. This is a retrospective comparison to an existing predicate device's specifications and prospective engineering testing of the new device's physical and electrical properties.

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

Not applicable. This submission is for substantial equivalence of a TENS device based on engineering and performance testing, not a diagnostic or clinical study requiring expert-established ground truth from patient data. The "ground truth" here is the adherence to electrical engineering specifications and safety standards as outlined by regulatory bodies and voluntary standards.

4. Adjudication method for the test set

Not applicable. No expert adjudication of clinical cases was performed, as this was not a clinical study involving interpretation of patient data.

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 device is a TENS unit, not an AI-powered diagnostic or assistive tool for human readers. No MRMC study was conducted.

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

Not applicable. This is a physical medical device (TENS unit), not an algorithm. Its "standalone" performance refers to its operational characteristics (output voltage, current, etc.) which were assessed through engineering tests as described in the comparison tables.

7. The type of ground truth used

Engineering Specifications and Safety Standards (e.g., ANSI/AAMI, IEC 60601-1, IEC 60601-1-2): The "ground truth" for this submission is adherence to established electrical and mechanical safety standards and conformity to the operational parameters of a legally marketed predicate device (Well-Life OTC TENS, K091757), which itself was cleared based on similar principles.

8. The sample size for the training set

Not applicable. This device does not use machine learning or AI, so there is no training set in the conventional sense.

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

Not applicable. As there is no training set, this is irrelevant.

Summary

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510(K) Summary

SEP 7 2012

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

The assigned 510(k) number is: K121353

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: August 17, 2012

Name of the Device:

Trade/Device Name: Mini Patch, model : WL-2301A & WL-2301B. Regulation Number: 21 CFR 882.5890 Regulation Name: Stimulator, Nerve, Transcutaneous For Pain Relief. Requlatory Class: II -Product Code: NUH

Information of the 510(k) Cleared Device (Predicate Device): ന് Well-Life OTC TENS for Arm & Leg Pain Relief. (K091757)

Device Description:

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5. Intended Use:

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

Compliance to applicable voluntary standards includes ANSI/AAMI, NS4-1985, 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.

7. Comparison of Significant device features

ComparisonFeatures	Models to be Compared
Model	OTC TENS for Arm & Leg	Mini Patch
510(K) No.	WL-2407	WL-2301A & WL-2301B
Prescription orOTC	K091757	K121353
Indication for use	OTC	Same
FDA product code	intended for temporary relief of painassociated with sore and achingmuscles in the upper and lowerextremities (arm and/or leg) due tostrain from exercise or normalhousehold and work activities	Same
Electrode Used	NUH	Same
Manufacturer	K082065, Snap Type self adhesiveelectrode (5 X 5 cm)	K082065, Snap Type self adhesiveelectrode (2.925 x 5.6 cm)
	Well-Life	Same

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8. Comparison of Unit Characteristics & Output Specification

Parameter		Predicate Device	New Device
510(K) Number		K091757	K121353	K121353
Device Name and Model		WL-2407	WL-2301A	WL-2301B
	Manufacturer	Well-Life	Same	Same
	Power Source(s)	1.5Vx3(AAA Size)	3Vx1	3Vx1
	- Method of Line current Isolation	Type BF	Same	Same
	- Patient Leakage Current	---	---	---
	- Normal condition (uA)	Under 0.1	Same	Same
	- single Fault condition (uA)	Under 0.5	Same	Same
Average DC current through electrodes whendevice is on but no pulses are being applied(UA)		Not applicable	Same	Same
	Number of Output Modes	8	3	3
Number of OutputChannels:	Synchronous orAlternating?	Synchronous	Same	Same
	Method of ChannelIsolation	Output Coil	Same	Same
	Regulated Current or Regulated Voltage?	Voltage	Same	Same
	Software/Firmware/Microprocessor control?	Yes	Same	Same
	Automatic Overload Trip?	No	Same	Same
	Automatic No-Load Trip?	Yes	Same	Same
Automatic Shut Off?		Yes	Same	Same
User Override control?		No	Same	Same
Indicator Display:	On/Off Status?	Yes	Same	Same
	Low Battery?	Yes	Same	Same
	Voltage/CurrentLevel?	Yes	Same	Same
Timer Range (Minutes)		5~60	20	20
Compliance with Voluntary Standards?		ANSI/AAMI NS4,IEC 60601-1 &IEC 60601-1-2.	Same	Same
Compliance with 21 CFR 898?		Yes	Same	Same
Weight (g)		43	20	20
Dimensions (mm.)[W x H x D]		90×52.5×19.4	59×30×12.15	60.2×31.9×14.4
Housing Materials and construction		ABS	Same	Same

15121353

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Parameter	Predicate Device	New Device
Mode or Program Name	WL-2407	WL-2301A WL-2301B
Waveform (e.g., pulsed monophasic, biphasic)	Biphasic	Same Same
Shape (e.g., rectangular, spike, rectified sinusoidal)	Rectangular (with deformation on the top of each pulse)	Same Same
Maximum Output Voltage (volts) (+/- 20 %)	40V@500Ω62V@2kΩ104V@10kΩ	30V@500Ω50V@2kΩ80V@10kΩ 30V@500Ω50V@2kΩ80V@10kΩ
Maximum Output Current (specify units) (+/- 20 %)	80mA@500Ω31mA@2kΩ10.4mA@10kΩ	60mA@500Ω25mA@2kΩ8.0mA@10kΩ 60mA@500Ω25mA@2kΩ8.0mA@10kΩ
Duration of primary (desplarizing) phase (usec)	260 Max	250 Max 250 Max
Pulse Duration (usec)	500.26 ms/Max.	33.58 ms/Max. 33.58 ms/Max.
Frequency (Hz) [or Rate (pps)]	60 Max	60 Max 60 Max
Formultiphasicwaveformsonly:	Symmetrical phases?Phase Duration (include units), (Stage range, if applicable), (both phases, if asymmetrical)	NoNot applicable SameSame SameSame

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K121353

9. Significant output characteristics comparison table:

Comparison feature	Model		Remarks
Net charge	WL-2407	WL-2301/2301B	Note 1
Max. phase charge	20.8 uc	15uc
Max. current Density	0.050 mA/cm²	0.055 mA/cm²
Max. Averagecurrent(RMSA)	500 Ω	38.43mA	29.394 mA
	2K Ω	14.892mA	12.248 mA
	10 Ω	4.996mA	3.9192 mA
Max. Power Density	0.0020Watts/ cm²	0.0017Watts/ cm²
Burst Mode	No	6Sec/On & 1Sec/Off

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

10. Conclusions

The Well-Life Mini Patch, model: WL-2301A & WL-2301B Transcutaneous Electrical Nerve Stimulators has the same intended use and the similar technological characteristics as the cleared device- Well-Life OTC TENS for Arm & Leg Pain Relief. (K091757) . Moreover, verification and validation tests contained in this submission demonstrate that the difference in the submitted 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/1 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo is a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is an abstract image of an eagle.

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

SEP 7 2012

Well Life Healthcare, Ltd % Ms. Jenny Hsieh 1F1, No.16, Lane 454, Jungjeng Rd. Yunghe City, Taipei County Taiwan, R.O.C.

Re: K121353

Trade/Device Name: Mini Patch, Model WL-2301A & WL-2301B Regulation Number: 21 CFR 882.5890 Regulation Name: Transcutaneous Electrical Nerve Stimulator for Pain Relief Regulatory Class: II Product Code: NUH Dated: August 17, 2012 Received: August 21, 2012

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 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 statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical

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device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) 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 go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. 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/ReportalProblem/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/Resourcesfor You/Industry/default.htm.

Sincerely yours.

Kesia Alexander

Malvina B. Eydelman, M.D. Director Division of Ophthalmic, Neurological, and Ear, Nose and Throat Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications For Use

510(k) Number (if known): K121353

Device Name: Mini Patch, model : WL-2301A & WL-2301B

Indications For Use:

Prescription Use (Part 21 CFR 801 Subpart D) Over-The-Counter Use (21 CFR 807 Subpart C)

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Kunz

(Division Sign-Off) Division of Ophthalmic, Neurological and Ear, Nose and Throat Devices

510(k) Number K121353

Regulation Number and Section

§ 882.5890 Transcutaneous electrical nerve stimulator for pain relief.

(a)
Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.(b)
Classification. Class II (performance standards).