(108 days)
To be used for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, arm, leg and foot, due to strain from exercise or normal household and work activities
The Low-Frequency Therapy Instrument is a product that adopts modern electronic science and technology to produce low-frequency electrical pulse and transmit that through the skin to the underlying peripheral nerves by electrodes, in order to reach the therapeutic aim.
There are three models of Low-Frequency Therapy Instrument which are KTR-201, KTR-202, KTR-203. Their technical parameters are slightly different, but they share the basically same characteristics: 1) They are small, and exquisite; 2) they have different treatment modes which can satisfy various demands, thus can be used by a wider range of people; 3) LCD display with a big screen makes the operation easy and clear, and the contents displayed on LCD can guide the treatment.
The Low-Frequency Therapy Instrument is mainly composed of the host and electrode patches and it uses AAA batteries for power supply. To start therapy, first insert batteries, then paste the electrode patches onto treatment areas and press power button to turn the power on. The modes and intensity can be selected according to needs. The current status is displayed on LCD.
This FDA 510(k) submission describes the "Low-Frequency Therapy Instrument" (Models: KTR-201, KTR-202, KTR-203), a Transcutaneous Electrical Nerve Stimulator (TENS) for pain relief.
Here's an analysis of the acceptance criteria and supporting studies based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with corresponding performance metrics. Instead, the acceptance is implied by demonstrating substantial equivalence to a predicate device (Shenzhen OSTO Technology Company Limited's Health Expert Electronic Stimulator, Model AST-300C and AST-300D, K133929) and compliance with relevant voluntary standards.
The "Technological characteristics and substantial equivalence" table (pages 5-6) serves as the core comparison for "performance." Key metrics and their comparison to the predicate are:
| Parameter | Subject Device (K170205) | Primary Predicate (K133929) | Remark / Implied Acceptance |
|---|---|---|---|
| Indications for Use | Temporary pain relief for sore/aching muscles (shoulder, waist, back, arm, leg, foot) due to strain from exercise/normal activities. | Temporary pain relief for sore/aching muscles (shoulder, waist, back, back of the neck, arm, leg, foot) due to strain from exercise/normal activities by applying current to stimulate nerve. | Similar. The subject device's indications are slightly narrower (omitting "back of the neck"), but fundamentally the same therapeutic area and type of pain relief. Implied acceptance: performs a similar therapeutic function for similar conditions. |
| Regulation Number | 21 CFR 882.5890 | 21 CFR 882.5890 | Identical. Implied acceptance: operates under the same regulatory classification. |
| Product Code | NUH | NUH, NGX | Similar. NUH is shared, indicating the core function. Implied acceptance: fits the same product category. |
| Class | Class II | Class II | Identical. Implied acceptance: same regulatory class. |
| OTC/Rx | OTC | OTC | Identical. Implied acceptance: same intended availability. |
| Power Supply | KTR-201: DC 3V, 30 mA; KTR-202: DC 4.5V, 100 mA; KTR-203: DC 3V, 30mA | 100-240VAC, 50-60Hz, 0.1A | Different. Predicate is mains-powered. Remark states: "Predicate is powered by mains supply but does not affect safety and effectiveness of subject device." Implied acceptance: different power source does not compromise safety/effectiveness. |
| Output Modes | KTR-201: 10; KTR-202: 10; KTR-203: 5 | 25 | Identical. (This remark seems incorrect; the numbers are different for all subject models compared to the predicate's 25. It should likely state "Similar" or "Different but does not affect...") Implied acceptance: sufficient modes for therapy. |
| Output Channels | KTR-201: 1; KTR-202: 1; KTR-203: 2 | 2 | Similar. Remark states: "Does not affect safety and effectiveness of subject device." Implied acceptance: sufficient channels for therapy. |
| Timer Range | 15 mins | 25 mins | Different. Remark states: "Different but does not affect safety and effectiveness of subject device." Implied acceptance: sufficient timer for therapy sessions. |
| Waveform | Pulsed symmetric, biphasic, square wave | Pulse symmetric, biphasic, rectangular with interphase interval | Similar. Implied acceptance: provides therapeutically similar electrical stimulation. |
| Max Output Voltage | 44V@500ohm, 58V@2kohm, 63.5V@10kohm | 44V±10% @500ohm, 80V±10% @2kohm, 112V±10@10kohm | Similar. Implied acceptance: within acceptable therapeutic range. |
| Max Output Current | 88mA@500ohm, 29mA@2kohm, 6.35mA@10kohm | 88mA±10% @500ohm, 40mA±10% @2kohm, 11.2mA±10% @ 10kohm | Similar. Implied acceptance: within acceptable therapeutic range. |
| Net Charge (per pulse) | 0µC @500ohm | 0µC @500ohm | Identical. Important for safety to prevent DC component. Implied acceptance: safe. |
| Max Phase Charge | 11.7µC @500ohm | 12.78μC@500ohm | Similar. Implied acceptance: therapeutically comparable and safe. |
| Max Average Current (500ohm) | 7.4mA | 0.968mA | Different. Remark states: "Although the maximum average current is different, it is <10mA, which complies with the requirements of IEC 60601-2-10, so the difference does not affect safety and effectiveness of the subject device." Implied acceptance: safe and meeting standard. |
| Max Current Density | 0.15mA/cm²@500ohm | 0.235mA/cm²@500ohm | Different. Remark states: "Current density is <2mA/cm² which complies with the requirements of IEC 60601-2-10, so the difference does not affect safety and effectiveness of the subject device." Implied acceptance: safe and meeting standard. |
| Max Power Density | 0.56mW/cm²@500ohm | 1.38mW/cm²@500ohm | Different. Remark states: "Power density is <0.25W/cm² and does not affect safety and effectiveness of the subject device." (Note: The provided predicate value is 1.38mW/cm², which is 0.00138W/cm², significantly less than 0.25W/cm². The remark aligns with this.) Implied acceptance: safe and meeting standard. |
| Pulse Frequency | 1-200Hz | 77.3Hz | Similar. Implied acceptance: provides flexible yet therapeutically relevant frequencies. |
| Pulse Duration | 50-220us | 120us | Similar. Implied acceptance: provides flexible yet therapeutically relevant pulse durations. |
The primary "acceptance criteria" here are substantial equivalence to the predicate device and compliance with recognized IEC standards. The study aims to demonstrate that its electrical characteristics and safety parameters are comparable or fall within accepted safety limits defined by these standards, despite some differences from the predicate.
2. Sample Size Used for the Test Set and Data Provenance
The document describes non-clinical tests only. There is no mention of a clinical test set involving human subjects for performance or efficacy evaluation. The "data provenance" therefore refers to the origin of engineering and safety test results, rather than clinical data.
- Sample Size: Not applicable as no clinical test set is described. The relevant "samples" would be the units of the device models (KTR-201, KTR-202, KTR-203) used for engineering and electrical testing. The exact number of units tested is not specified but is typically a small number for such compliance testing.
- Data Provenance: The tests are non-clinical (engineering, electrical, software, biocompatibility). These tests were conducted by the manufacturer (Shenzhen Kentro Medical Electronics Co., Ltd) or accredited labs. The nationality is implied to be China, where the manufacturer is located. All tests are inherently prospective as they are conducted specifically to support this 510(k) submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not applicable. As no clinical test set is described, there is no "ground truth" established by medical experts for performance or efficacy. The "ground truth" in this context would be the specifications and requirements of the relevant IEC standards (e.g., IEC60601-1, IEC60601-2-10) and FDA guidance, against which the device's electrical outputs were measured. Compliance is determined by whether the measured parameters fall within the limits set by these standards.
4. Adjudication Method for the Test Set
Not applicable. Since there's no clinical data or human assessment of primary endpoints, no expert adjudication method (like 2+1, 3+1) is described or needed.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. An MRMC comparative effectiveness study is a type of clinical study involving multiple readers (e.g., radiologists) evaluating multiple cases (e.g., medical images) to compare the diagnostic performance of different methods or devices. This is not applicable to a TENS device, which provides direct therapeutic electrical stimulation, not diagnostic information. The submission focuses on substantial equivalence based on technical specifications and safety standards, not comparative clinical effectiveness.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
The device itself is a standalone therapeutic device; it is not an algorithm that requires human input to interpret its output in the same way an AI-powered diagnostic tool would. Its "standalone performance" is implicitly demonstrated through the non-clinical tests (electrical output, safety, software validation) showing it meets its design specifications and relevant standards. The device is intended for over-the-counter (OTC) use by consumers without professional human-in-the-loop operation, reflecting its standalone nature.
7. The Type of Ground Truth Used
The "ground truth" for this device's acceptance is:
- Engineering/Performance Specifications: The device's own design specifications for output parameters (voltage, current, frequency, pulse duration, waveform).
- Voluntary Consensus Standards: The requirements and limits defined by international standards such as IEC 60601-1 (general safety), IEC 60601-1-11 (home healthcare environment), IEC 60601-2-10 (nerve and muscle stimulators), and IEC 60601-1-2 (EMC). For biocompatibility, ISO 10993-5 and ISO 10993-10 for the electrode patches.
- Predicate Device Characteristics: The established safety and effectiveness profile of the legally marketed predicate device (K133929), used as a benchmark for substantial equivalence.
There is no pathology or outcomes data from a clinical trial presented as ground truth.
8. The Sample Size for the Training Set
Not applicable. This device is an electrical stimulation device, not an AI/machine learning algorithm that requires a "training set" of data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set is used for this type of device.
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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
May 11, 2017
Shenzhen Kentro Medical Electronics Co., Ltd Tracy Che Application Correspondent No.3, Xihu Industry Zone, Xikeng Village, Henggang Town Longgang District Shenzhen City, 518115 CN
Re: K170205
Trade/Device Name: Low-Frequency Therapy Instrument /Model: KTR-201, KTR-202, KTR-203 Regulation Number: 21 CFR 882.5890 Regulation Name: Transcutaneous Electrical Nerve Stimulator For Pain Relief Regulatory Class: Class II Product Code: NUH Dated: April 24, 2017 Received: April 26, 2017
Dear Tracy Che:
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
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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 devicerelated 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 contact the Division of Industry and Consumer Education 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. 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
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 Industry and Consumer Education 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,
William J. Heetderks -S
for Carlos L. Peña, PhD, MS 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) K170205
Device Name
Low-Frequency Therapy Instrument/Model: KTR-201, KTR-202, KTR-203
Indications for Use (Describe)
To be used for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, arm, leg and foot, due to strain from exercise or normal household and work activities
Type of Use (Select one or both, as applicable)
Prescription Use (Part 21 CFR 801 Subpart D)
|X | Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) Summary K170205
(1) Applicant information:
| 510(k) owner's name: | SHENZHEN KENTRO MEDICAL ELECTRONICS CO., LTD |
|---|---|
| Address: | No.3, Xihu Industry Zone, Xikeng Village, Henggang Town,Longgang District, Shenzhen City, Guangdong Province, China |
| Contact person: | Zewu Zhang |
| Phone number: | +86 755 3382 5998 |
| Fax number: | +86 755 3382 5996 |
| Email: | kentro@kentro.com.cn |
| Date of summary prepared: | May 4, 2017 |
(2) Proprietary name of the device
| Trade name/model: | Low-Frequency Therapy Instrument /Model: KTR-201,KTR-202, KTR-203 |
|---|---|
| Common name: | Transcutaneous Electrical Nerve Stimulator |
| Regulation number: | 21CFR 882.5890 |
| Product code: | NUH |
| Review panel: | Neurology |
| Regulation class: | Class II |
(3) Predicate devices
| Sponsor | Shenzhen OSTOTechnologyCompany Limited | EnduranceTherapeutics | Tyece Ltd. | M.i.tech Co.,Ltd. |
|---|---|---|---|---|
| Device Nameand Model | Health ExpertElectronicStimulator, ModelAST-300C andAST-300D | T1040Aurawave | Tyece OTCTENS Device,Model SEM44 | HANAROCareReJu |
| 510(k)Number | K133929 | K124055 | K150386 | K160893 |
| ProductCode | NUH, NGX | NUH, NYN, NGX,GZJ | NUH | NUH |
| Regulation | 21 CFR 882.5890 | 21 CFR 882.5890 | 21 CFR | 21 CFR |
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| Number | 882.5890 | 882.5890 | ||
|---|---|---|---|---|
| RegulationClass | II | II | II | II |
(4) Description/ Design of device:
The Low-Frequency Therapy Instrument is a product that adopts modern electronic science and technology to produce low-frequency electrical pulse and transmit that through the skin to the underlying peripheral nerves by electrodes, in order to reach the therapeutic aim.
There are three models of Low-Frequency Therapy Instrument which are KTR-201, KTR-202, KTR-203. Their technical parameters are slightly different, but they share the basically same characteristics: 1) They are small, and exquisite; 2) they have different treatment modes which can satisfy various demands, thus can be used by a wider range of people; 3) LCD display with a big screen makes the operation easy and clear, and the contents displayed on LCD can guide the treatment.
The Low-Frequency Therapy Instrument is mainly composed of the host and electrode patches and it uses AAA batteries for power supply. To start therapy, first insert batteries, then paste the electrode patches onto treatment areas and press power button to turn the power on. The modes and intensity can be selected according to needs. The current status is displayed on LCD.
(5) Intended use / indications:
To be used for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, arm, leg and foot, due to strain from exercise or normal household and work activities.
(6) Materials
| Component name | Material ofComponent | Body ContactCategory | Contact Duration |
|---|---|---|---|
| Electrode patches | Hydrogel | Surface skin contact | Less than 24 hours |
We have directly purchased electrode patches from qualified supplier which has obtained FDA clearance with a 510(k) number of K152815 and been legally marketed to US market. For details, please refer to "Biocompatibility Discussion".
(7) Technological characteristics and substantial equivalence:
| Parameters | Subject(K170205) | device | Primary predicate(K133929) | Remark |
|---|---|---|---|---|
| Trade name | Low-Frequency | Health | Expert | N/A |
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| Therapy Instrument(Model: KTR-201, KTR-202, KTR-203) | Electronic Stimulator,Model: AST-300C and AST-300D | ||
|---|---|---|---|
| Indications for Use | To be used for temporary relief of pain associated with sore and achingmuscles in the shoulder, waist, back, arm, legand foot, due to strain from exercise ornormal household and work activities. | To be used for temporary relief of pain associated with sore andachingmuscles in the shoulder, waist, back, back ofthe neck, arm, leg,and foot due to strain fromexercise or normal household workactivities by applyingcurrent tostimulate nerve. | Similar |
| Regulation number | 21 CFR 882.5890 | 21 CFR 882.5890 | Identical |
| Product code | NUH | NUH, NGX | Similar |
| Class | II | II | Identical |
| OTC/Rx | OTC | OTC | Identical |
| Basic unit specifications | |||
| Power supply | KTR-201: DC 3V, 30 mAKTR-202: DC 4.5V, 100 mAKTR-203: DC 3V, 30mA | 100-240VAC, 50-60Hz, 0.1A | Predicate ispowered by mainssupply but does notaffect safety andeffectiveness ofsubject device |
| Output modes | KTR-201: 10KTR-202:10KTR-203: 5 | 25 | Identical |
| Output channels | KTR-201: 1KTR-202:1KTR-203: 2 | 2 | Similar. Does notaffect safety andeffectiveness ofsubject device. |
| Software | Yes | Yes | Identical |
| Automatic Shut off | Yes | Yes | Identical |
| Timer range | 15 mins | 25 mins | Different but doesnot affect safetyand effectivenessof subject device. |
| Dimensions | KTR-201: 147mm x59mm x 27.5mm | 428mm x 428.8mm x185mm | Not applicable |
| 100mm x 46mmKTR-203: 98.9mm x64mm x 31.25mm | |||
| Weight | KTR-201 (Host): 2.7ozKTR-202 (Host): 5.7ozKTR-203 (Host): 1.7oz | 70.5oz (2kg) (without accessories) | Not applicable |
| Housing materialand construction | ABS | ABS | Identical |
| Compliance withvoluntarystandards | IEC60601-1;IEC60601-1-2;IEC60601-1-11;IEC-60601-2-10 | IEC60601-1;IEC60601-1-2;IEC-60601-2-10;ISO10993-5;ISO10993-10 | Similar |
| Compliance with21 CFR 898 | Yes | Yes | Identical |
| Output specifications | |||
| Waveform | Pulsed symmetric, biphasic, square wave | Pulse symmetric, biphasic, rectangularwith interphase interval | Similar |
| Maximum outputvoltage (Vp) | 44V@500ohm58V@2kohm63.5V@10kohm | 44V±10% @500ohm80V±10% @2kohm112V±10@10kohm | Similar |
| Maximum outputcurrent | 88mA@500ohm29mA@2kohm6.35mA@10kohm | 88mA±10% @500ohm40mA±10% @2kohm11.2mA±10% @ 10kohm | Similar |
| Net charge (perpulse) | 0µC @500ohm | 0µC @500ohm | Identical |
| Maximum phasecharge | 11.7µC @500ohm | 12.78μC@500ohm | Similar |
| Maximum AverageCurrent (500ohm) | 7.4mA | 0.968mA | Although themaximum averagecurrent is different,it is <10mA, whichcomplies with therequirements ofIEC 60601-2-10,so the differencedoes not affectsafety andeffectiveness of thesubject device. |
| Maximum currentdensity | 0.15mA/cm²@500ohm | 0.235mA/cm²@500ohm | Current density is<2mA/cm² whichcomplies with the |
| requirements ofIEC 60601-2-10,so the differencedoes not affectsafety andeffectiveness of thesubject device. | |||
| Maximum powerdensity | 0.56mW/cm²@500ohm | 1.38mW/cm²@500ohm | Power density is<0.25W/cm² anddoes not affectsafety andeffectiveness of thesubject device |
| Pulse frequency | 1-200Hz | 77.3Hz | Similar |
| Pulse duration | 50-220us | 120us | Similar |
| ON time | No | 0.6s | Does not affectsafety andeffectiveness ofsubject device |
| OFF time | No | 0.6s | Does not affectsafety andeffectiveness ofsubject device |
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(8) Non-clinical studies and tests performed:
Non-clinical tests have been conducted to verify that the low-frequency therapy instrument meets all design specifications which supports the conclusion that it's Substantially Equivalent (SE) to the predicate device. The testing results demonstrate that the targeted device complies with the following standards:
- A IEC60601-1, Medical electrical equipment -- Part 1: General requirements for basic safety and essential performance
- A IEC60601-1-11, Medical electrical equipment -- Part 1-11: General requirements for basic safety and essential performance -- Collateral standard: Requirements for medical electrical equipment and medical electrical systems used in the home healthcare environment
- A IEC60601-2-10, Medical electrical equipment -- Part 2-10: Particular requirements for the basic safety and essential performance of nerve and muscle stimulators
- A IEC60601-1-2, Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic disturbances -Requirements and tests
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The body-contacting components of this device are electrode patches. We have directly purchased the electrode patches from qualified supplier which has obtained FDA clearance with a 510(k) number of K152815 and been marketed to US market. So we have reason to believe that the electrode patches are safe for the users. The electrode patches comply to the following standards.
- A ISO 10993-5, Biological Evaluation Of Medical Devices -- Part 5: Tests For InVitro Cytotoxicity
-
ISO 10993-10, Biological Evaluation Of Medical Devices - Part 10: Tests For Irritation And Skin Sensitization.
We have also conducted:
- A Software verification and validation test according to the requirements of the FDA "Guidance for Pre Market Submissions and for Software Contained in Medical Devices"
- A The waveform test report has also been conducted to verify the output specifications of the device according to Guidance for Transcutaneous Electrical Nerve Stimulator for Pain Relief Intended for Over the Counter Use
(9) Conclusion
Based on the above analysis and tests performed, it can be concluded that the performance and function of Low-Frequency Therapy Instrument are normal, safe and effective, and it is Substantially Equivalent (SE) to the predicate devices.
§ 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).