The Mini-TENS including a series of TENS models (WL-2401, WL-2402, WL-2403, and WL-2302) is intended for symptomatic relief of chronic intractable pain.

Device Description

The Mini-TENS series, including WL-2401, WL-2402, WL-2403, and WL-2302 are transcutaneous electrical nerve stimulator used for pain relief by applying an electrical current to electrodes, which are attached on the patient's skin. The output and waveform is adjustable according to the situation of patient.

Mini-TENS series, models WL-2401, WL-2402, WL-2403, and WL-2302, 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-TENS 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-2102A. Every model of Mini-TENS has its individual stimulation operation cycle.

The Mini-TENS series (WL-2401, WL-2402, WL-2403, and WL-2302) are almost identical in function outlook and specification.

AI/ML Overview

This document describes the 510(k) summary for the Well-Life Mini-TENS series (models WL-2401, WL-2402, WL-2403, and WL-2302), which are transcutaneous electrical nerve stimulators (TENS devices). The purpose of this submission is to demonstrate substantial equivalence to a legally marketed predicate device (Well-TENS, model WL-2102A).

This submission does not contain information related to the performance of an AI/ML device in the context of acceptance criteria from a study. It focuses on the comparison of specifications and intended use of new TENS device models against a predicate TENS device for 510(k) clearance. Therefore, a table of acceptance criteria and reported device performance isn't applicable in the context of an "AI/ML device" and a study proving it meets acceptance criteria.

However, I can extract the comparative information presented in the document, which serves as the basis for determining substantial equivalence for these medical devices.

Summary of Device Comparison and Non-Clinical Tests (as presented in the 510(k) submission):

The document presents a comparison of the new Mini-TENS series with the predicate device (WL-2102A) to demonstrate substantial equivalence. The "acceptance criteria" here implicitly refer to the notion that the new devices should not raise new questions of safety or effectiveness, and their characteristics should be comparable to or within acceptable limits relative to the predicate device and relevant standards.

Table of Performance Comparisons for Substantial Equivalence (derived from the document):

Feature/Specification	Predicate Device (WL-2102A)	New Device Models (WL-2401, WL-2402, WL-2403, WL-2302)	Comments on Equivalence
Intended Use	Pain relief (TENS device)	Symptomatic relief of chronic intractable pain	Same intended use
Operation Mode	3 modes (B/C/M)	1 mode (Burst mode)	Simplified operation, considered safe and effective by comparison to predicate's burst mode.
Output Channels	2	1	Different, but not raising new safety/effectiveness concerns.
Power Source	1x9V Alkaline, Type BF	1x3V Lithium, Type BF	Different battery, but still Type BF for isolation and leakage current within limits.
Normal Condition Line Current Isolation	< 0.001mA	< 0.001mA	Equivalent
Single Fault Condition Line Current Isolation	Not tested	Not tested	Consistent with predicate.
Regulated Current/Voltage	Regulated Current (RC)	Regulated Current (RC)	Equivalent
Software/Firmware/Microprocessor	Firmware	Firmware	Equivalent
Automatic Overload Trip	No	No	Equivalent
Automatic No-Load Trip	No	No	Equivalent
Automatic Shut Off	Yes	Yes	Equivalent
Patient Override Control	No	No	Equivalent
Indicator Display (On/Off)	Yes	Yes	Equivalent
Indicator Display (Low Battery)	No	No	Equivalent
Indicator Display (Voltage/Current Level)	No	No	Equivalent
Timer Range	15/30/60 mins adjustable	15, 30, or 60 mins fixed (model dependent)	Different, but considered safe and effective.
Compliance with Voluntary Standards	ANSI/AAMI NS4	ANSI/AAMI NS4, EN 60601-1, EN 60601-1-1, EN 60601-1-2	New models meet broader and additional standards.
Compliance with 21 CFR 898	Yes	No	Not applicable to new models based on transition period.
Weight	135 g	19 g (WL-2401/02), 19 g (WL-2403/02)	Lighter weight, not impacting safety/effectiveness.
Dimensions	92x62x25 in	Varied (e.g., 60x47.3x14.6 in)	Smaller dimensions, not impacting safety/effectiveness.
Housing Materials	Plastic	Plastic	Equivalent
Waveform Type	Biphasic	Biphasic	Equivalent
Waveform Shape	Rectangular	Rectangular	Equivalent
Max Output Voltage (@500Ω)	38V	32V (WL-2401/02), 38.2V (WL-2403/02)	Within acceptable physiological range.
Max Output Current (@500Ω)	+76mA	+64mA (WL-2401/02), +76.2mA (WL-2403/02)	Within acceptable physiological range.
Pulse Width (us)	30-260 adjustable	Fixed/changeable (e.g., 250, 150-250)	Within acceptable range.
Frequency (Hz)	2-150 adjustable	Fixed/changeable (e.g., 30, 30-60)	Within acceptable range.
Net Charge (µC per pulse) @500 Ω	20.8	16.0 (WL-2401/02), 8.76 (WL-2403/02)	Within acceptable range.
Maximum Phase Charge (µC)	22	12.5 (WL-2401/02), 9.2 (WL-2403/02)	Within acceptable range.
Maximum Current Density (mA/cm²)	0.18525	Varied (e.g., 0.0333 to 0.007)	Lower/safer than predicate.
Maximum Power Density (W/cm²)	0.0070395	Varied (e.g., 0.0010656 to 0.0002674)	Lower/safer than predicate.

Study Information (Based on the provided document):

Sample size used for the test set and the data provenance: Not applicable. This submission relies on engineering specifications comparison and compliance with voluntary standards, rather than testing on a biological "test set" with data provenance in the context of an AI/ML device. The document explicitly states: "The WL-2402 is the most complicate in these three models, so the assessment results for the features of performance and safety of this model could cover that of the other three models." This suggests a representative model was chosen for detailed assessment, but this isn't a "sample size" in the usual clinical study sense.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth from experts is not a concept used in this type of device submission, which relies on objective measurements against engineering specifications and voluntary standards.
Adjudication method (e.g., 2+1, 3+1, none) for the test set: Not applicable. No clinical test set or adjudication process described.
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/ML device, and no MRMC study was performed.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is not an AI/ML device.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not applicable in the context of AI/ML. For this device, the "ground truth" or basis for acceptance is adherence to established engineering specifications, safety standards (ANSI/AAMI NS4-1985, EN 60601-1, etc.), and demonstrating that any differences from the predicate device do not raise new questions of safety or effectiveness. The device's performance is objectively measured against these defined technical criteria.
The sample size for the training set: Not applicable. This is not an AI/ML device and does not involve a training set.
How the ground truth for the training set was established: Not applicable. This is not an AI/ML device.

Conclusion stated in the 510(k) Summary:

The submitter concludes that the Mini-TENS series has the "same intended use and technological characteristics as the cleared device WL-2102A. 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."
The engineering differences identified "do not: (1) affect the intended use or (2) alter the fundamental scientific technology of the device." This forms the basis for the FDA's substantial equivalence determination.

Summary

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510(K) SUMMARY

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: _K020020

DEC 3 0 2002

Submitter's Identifications: Well-Life Healthcare Inc. Room 6C01, No. 5, Sec. 5, Hsin Yi Rd., Taipei, Taiwan, R.O.C.

Contact: Ms. Grace Chang Sales Manager

Date of Summary Preparation: October, 2001.

1. Name of the Device: Well-Life TENS (Transcutaneous Electrical Nerve Stimulation Device), Model Mini-TENS series. including WL-2401, WL-2402, WL-2403, and WL-2302.
1. Information of the 510(k) Cleared Device (Predicate Device):

4. Device Description:

The Mini-TENS series (WL-2401, WL-2402, WL-2403, and WL-2302) are almost identical in function outlook and specification. The main differences between these four models are indicated in the following table.

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Model	Outlook	Time foreachoperationcycle	Combination ofwave form	Wave form information
				Type	Pulse rate(Hz)	Pulse width(μs)	Timeduration
Mini-TENSWL-2401	Type A	60minutes	Single waveform (A)	A	30	250	3s/ON,5s/OFF
Mini-TENSWL-2402	Type B	15minutes	A/1min→B/1min→C/1min, repeat 5times	A	30~60auto-change	250	6s/ON,1s/OFF
				B	30	150~250auto change	6s/ON,1s/OFF
				C	30~60auto change	150~250auto change	6s/ON,1s/OFF
Mini-TENSWL-2403	Type C	30minutes	Single waveform (A)	A	25	115	4s/ON,1s/OFF
Mini-TENSWL-2302	Type C	15minutes	A/2min→B/2min→C/2min→B/2min→D/2min→B/2min→C/3min	A	2	115	2s/ON,1s/OFF
				B	30	115	2s/ON,1s/OFF
				C	4	115	ON
				D	15	115	4s/ON,1s/OFF

The WL-2402 is the most complicate in these three models, so the assessment results for the features of performance and safety of this model could cover that of the other three models.

While comparing with the original 510(k) clear device, WL-2102A. The main difference between burst mode operation of WL-2102A and Mini-TENS are indicated as the following table:

Comparisonfeatures	Clear model	New models
	WL-2102A	WL-2401	WL-2402	WL-2403	WL-2302
Timer control	15/30/60 minsadjustable	60 mins fixed	15 mins fixed	30 mins fixed	15 mins fixed
Burst durationtime	0.1s/ON,0.4s/OFF	3s/ON, 5s/OFF	6s/ON, 1s/OFF	4s/ON, 1s/OFF	2s/ON, 1s/OFFor 4s/ON,1s/OFF oralways ON
Pulse rate(Hz)	100Hz fixed	30Hz fixed	30~60Hz autochange	25Hz fixed	2/4/15/30 Hzauto change
Pulse width(μs)	0~260μsadjustable	250μs fixed	150~250μsauto change	115μs fixed	115μs fixed
Amplitude(mA)	0~80mAadjustable	0~50mAadjustable	0~50mAadjustable	0~50mAadjustable	0~50mAadjustable
Combinationfor the type ofwave form	Single (A)	Single (A)	3 wave formscombination:A(1m)→B(1m)→C(1m), 5repeat	Single (A)	4 wave formscombination:A(2m)→B(2m)→C(2m)→B(2m)→D(2m)→B(2m)→C(3m)

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ANNEX II

5. Intended Use:

Mini-TENS series including WL-2401, WL-2402, WL-2403, and WL-2302, is a portable, batterypowered, transcutaneous electrical nerve stimulators (TENS device) that are used in the treatment of pain syndromes, that is intended for use on intact skin, and that do not require surgical intervention or violation of the skin surface.

The electrode is included in the packing of Mini-TENS series.

Because that all the performances tested are completely within the limit of standard, and all the labeling is provided according to the requirement of standard, the Well-TENS series fall completely within the scope of clause 1 of ANSI/AAMI NS4-1985.

6. Comparison to the 510(k) Cleared Device (Predicate Device):

Features	Clear model	New model
	WL-2102A	WL-2401	WL-2402	WL-2403	WL-2302
1. 510(k) Number	K002874	K020020	K020020	K020020	K020020
2. Device Name, Model	Well-TENS,WL-2102A	Mini-TENS,WL-2401	Mini-TENS,WL-2402	Mini-TENS,WL-2403	Mini-TENS,WL-2302
3. Manufacturer	Well-Life	Well-Life	Well-Life	Well-Life	Well-Life
4. Power Source(s)- Method of Line CurrentIsolation	1x9V AlkalineType BF	1x3V LithiumType BF	1x3V LithiumType BF	1x3V LithiumType BF	1x3V LithiumType BF
Normal conditionSingle fault condition	< 0.001mANot tested	< 0.001mANot tested	< 0.001mANot tested	< 0.001mANot tested	< 0.001mANot tested
5. Number of Output Modes	3 (B/C/M)	1 (Burstmode)	1 (Burstmode)	1 (Burstmode)	1 (Burstmode)
6. Number of Output Channels- Synchronous or	2	1	1	1	1
Alternating?- Method of ChannelIsolation	SynchronousType BF	SynchronousType BF	SynchronousType BF	SynchronousType BF	SynchronousType BF
7. Regulated Current orRegulated Voltage?	RC	RC	RC	RC	RC
8. Software/Firmware/microprocessor Control?	Firmware	Firmware	Firmware	Firmware	Firmware
9. Automatic Overload Trip?	No	No	No	No	No
10. Automatic No-Load Trip?	No	No	No	No	No
11. Automatic Shut Off?	Yes	Yes	Yes	Yes	Yes
12. Patient Override Control?	No	No	No	No	No
13. Indicator Display:On/Off Status?Low Battery?Voltage/Current Level?	YesNoNo	YesNoNo	YesNoNo	YesNoNo	YesNoNo
14. Timer Range	15/30/60minutesadjustable	60 minutes	15 minutes	30 minutes	15 minutes

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	Clear model	New model	WL-2401	WL-2402	WL-2403
Features	WL-2102A
15. Compliance with VoluntaryStandards?	ANSI/AAMINS4	ANSI/AAMINS4	ANSI/AAMINS4	ANSI/AAMINS4	ANSI/AAMINS4
16. Compliance with 21 CFR898? (*Becomesmandatory beginning May,9, 2000)	Yes	No	No	No	No
17. Weight (g)	135	19	19	19	19
18. Dimensions (in) [W×H×D]	92×62×25	60×47.3×14.6	60×47.3×14.6	56×26×8	56×26×8
19. Housing Materials andConstruction	Plastic	Plastic	Plastic	Plastic	Plastic

Table for the comparison of output specifications for mini TENS

	Clear model	New model
Specification	WL-2102A	WL-2401	WL-2402	WL-2403	WL-2302
Waveform(e.g., pulsed monophasic, biphasic)	Biphasic	Biphasic	Biphasic	Biphasic	Biphasic
Shape(e.g., rectangular, spike, rectifiedsinusoidal)	Rectangular	Rectangular	Rectangular	Rectangular	Rectangular
Maximum Output Voltage (+/-20%)
@ 500 Ω	38V	32V	32V	38.2V	38.2V
@ 2 kΩ	55V	42V	42V	52.8V	52.8V
@ 10 KΩ	130V	80.8V	80.8V	84.8V	84.8V
Maximum Output Current (+/-20%)
@ 500 Ω	+76mA	+64mA	+64mA	+76.2mA	+76.2mA
@ 2 kΩ	+55mA	+42mA	+42mA	+52.8mA	+52.8mA
@ 10 KΩ	+13mA	+8.08mA	+8.08mA	+8.48mA	+8.48mA
Pulse Width (us)	30-260adjustable	250	150~250changeable	250	250
Frequency (Hz)	2-150adjustable	30	30-60changeable	25	2, 4, 15, 30changeable
Beat Frequency(for interferential modes only)	NA	NA	NA	NA	NA
Symmetrical phases(for multiphasic waveform only)?	NA	NA	NA	NA	NA
Phase Duration(for multiphasic waveform only)	NA	NA	NA	NA	NA
Net Charge (µ C per pulse) @500 Ω	20.8	16.0	16.0	8.76	8.76
Maximum phase Charge (µC)	22	12.5	12.5	9.2	9.2
Maximum Current Density (mA/cm²)	0.18525	0.0333	0.0265	0.006	0.007
Maximum Power Density (W/cm²)	0.0070395	0.0010656	0.000848	0.0002292	0.0002674

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

Compliance to applicable voluntary standards includes ANSI/AAMI, NS4-1985, as well as E.N 60601-1, EN 60601-1-1, and EN 60601-1-2 requirement.

8. Conclusions

The Mini-TENS series transcutaneous electrical nerve stimulator, WL-2401, WL-2402, and WL-2403, and WL-2302, have the same intended use and technological characteristics as the cleared device WL-2102A. 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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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/5/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three curved lines representing its body and wings. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle.

ood and Drug Administration 200 Corporate Boulevard Rockville MD 20850

Mr. Tony C. S. Chang Wincent Consultant Co., Ltd. No. 5. Alley 5. Lane Cheng Hsing, Chung Ching Road, Pei Tun District, Taichung, Taiwan, R.O.C.

Re: K020020

Trade/Device Name: Mini-TENS Series TENS Devices Models WL-2401, WL-2402, WL-2403, WL-2302 Regulation Number: 21 CFR 882.5890 Regulation Name: TENS Device for Pain Relief Regulatory Class: Class II Product Code: GZJ Dated: December 11, 2002 Received: December 12, 2002

Dear Mr. Chang:

We have reviewed your Section 510(k) premarket notification of intent to market the devices referenced above and have determined the devices are 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 devices, 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.

If your devices are classified (see above) into either class II (Special Controls) or class III (PMA), they may be subject to such 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 devices 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 devices comply with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies.

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Page 2 - Mr. Tony C. S. Chang

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); 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.

This letter will allow you to begin marketing your devices as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your devices to a legally marketed predicate device results in a classification for your devices and thus, permits your devices to proceed to the market.

If you desire specific advice for your devices on our labeling regulation (21 CFR Part 801 and additionally 21 CFR Part 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4648. Additionally, for questions on the promotion and advertising of your devices, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely yours.

Matt-1-Mather-

Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative, and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Page

510(k) Number (if known) K020020

Device Name:__Mini-TENS / Model: WL-2401, WL-2402, WL-2403, WL-2302

Indications For Use:

The Mini-TENS including a series of TENS models (WL-2401, WL-2402, WL-2403, and WL-2302) is intended for symptomatic relief of chronic intractable pain.

J. Hall of Williams

ivision Sign-Off) Division of General, Restorative and Neurological Devices

10(k) Number K020020

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use X OR

Over-The-Counter Use

(Optional Format 1-2-96)

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).