(53 days)
The OTC Patch, Model WL-2406, is intended for temporary relief of pain associated with sore and aching muscles in the low back as well as upper and lower extremities (arm and/or leg) due to strain from exercise or normal household and work activities.
The OTC Patch, model WL-2406 is a single channel transcutaneous electrical nerve stimulator used for pain relief by applying an electrical current to electrodes, which are attached on the user's skin. The outbut and waveform characteristic is fixed for every operation mode, only the intensity is adjustable within specified limit. The OTC Patch, model WL-2406, 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 user's skin so as to transmit this stimulus current for pain relief. The stimulation modes for OTC Patch is pre-program modes with fixed pulse rate, frequency, and fixed timer, only amplitude is adjustable. This operation way is considered the simplification from the pre-program modes of comparison clear model, OTC TENS For Low Back Pain Relief/ Model WL-2406(K052785). Every operation mode of OTC Patch, model WL-2406 has its individual stimulation operation cycle. For the device included in this submission, we use the following of our 510(K) legally marketed predicate electrodes: K082065, "Well-Life Self Adhesive Electrode", CM Series/ model no. CM-130x70, size 130x70mm, snap type. With the combination of the main device parts, the device can be placed on the treatment locations as recommended in the user manual for temporary relief of pain associated with sore and aching muscles in the low back as well as upper and lower extremities (arm and/or leg) due to strain from exercise or normal household and work activities.
The provided document is a 510(k) summary for a Transcutaneous Electrical Nerve Stimulator (TENS) device, the OTC Patch, Model WL-2406. It focuses on demonstrating substantial equivalence to previously cleared predicate devices rather than proving independent efficacy through new clinical studies measuring clinical outcomes against acceptance criteria.
Therefore, the document does not contain the information requested regarding acceptance criteria and a study proving the device meets those criteria, as typically understood for an AI/CADe device. Instead, the "study" described is a non-clinical comparison to predicate devices.
However, I can interpret the request in the context of the provided document by extracting the comparison data that serves as the basis for the "substantial equivalence" claim.
Here's an analysis based on the available information:
1. Table of Acceptance Criteria and Reported Device Performance
In the context of a 510(k) for a TENS device, "acceptance criteria" are typically met by demonstrating that the new device shares the same intended use, fundamental technological characteristics, and similar performance specifications as legally marketed predicate devices, or that any differences do not raise new questions of safety or effectiveness. The reported device performance is presented as a comparison to these predicates.
| Feature | Acceptance Criteria (Predicate Device K052785, WL-2406) | Acceptance Criteria (Predicate Device K091757, WL-2407) | Reported Device Performance (New Device WL-2406) |
|---|---|---|---|
| Intended Use | Temporary relief of pain in low back | Temporary relief of pain in upper/lower extremities | Temporary relief of pain in low back and upper/lower extremities |
| Regulation Number | 21 CFR 882.5890 | 21 CFR 882.5890 | 21 CFR 882.5890 |
| Regulatory Class | II | II | II |
| Product Code | NUH | NUH | NUH |
| Waveform | Biphasic | Biphasic | Biphasic |
| Shape | Rectangular | Rectangular | Rectangular |
| Max Output Voltage | 25V @500Ω, 45V @2KΩ, 75V @10KΩ | 40V @500Ω, 60V @2KΩ, 100V @10KΩ | 25V @500Ω, 45V @2KΩ, 75V @10KΩ |
| Max Output Current | 50mA @500Ω, 22.5mA @2KΩ, 7.5mA @10KΩ | 80mA @500Ω, 30mA @2KΩ, 10mA @10KΩ | 50mA @500Ω, 22.5mA @2KΩ, 7.5mA @10KΩ |
| Duration of primary phase | 260 max µsec | 260 max µsec | 260 max µsec |
| Pulse Duration | 8700 max µsec | 650 max µsec | 8700 max µsec |
| Frequency | 120 max Hz | 60 max Hz | 120 max Hz |
| Symmetrical phases? | Yes | Yes | Yes |
| Power Source | 1.5Vx2 (AAA Size) | 1.5Vx3 (AAA Size) | 1.5Vx2 (AAA Size) |
| Method of Line Current Isolation | Type BF | Type BF | Type BF |
| Patient Leakage Current (Normal) | Under 0.1 uA | Under 0.1 uA | Under 0.1 uA |
| Patient Leakage Current (Single Fault) | Under 0.5 uA | Under 0.5 uA | Under 0.5 uA |
| Number of Output Modes | 8 | 8 | 8 |
| Number of Output Channels | Synchronous, Output Coil | Synchronous, Output Coil | Synchronous, Output Coil |
| Regulated | Voltage | Voltage | Voltage |
| Software/Firmware/Microprocessor control? | Yes | Yes | Yes |
| Automatic No-Load Trip? | Yes | Yes | Yes |
| Automatic Shut Off? | Yes | Yes | Yes |
| Low Battery Indicator? | Yes | Yes | Yes |
| Voltage/Current Level Indicator? | Yes | Yes | Yes |
| Timer Range | 10-60 Minutes | 5-60 Minutes | 10-60 Minutes |
| Compliance with Voluntary Standards | IEC 60601-2-10 | IEC 60601-2-10 | IEC 60601-2-10 |
| Compliance with 21 CFR 898? | Yes | Yes | Yes |
| Housing Materials | ABS | ABS | ABS |
| Method of achieving zero net charge | Biphasic symmetric wave for each | Biphasic symmetric wave for each | Biphasic symmetric wave for each |
| Electrode Used | Belt Electrode (5 X 5 cm)/K082065 | Belt Electrode and/or Self Adhesive Electrode(5 X 5 cm)/K082065 | Self Adhesive Electrode (13x7 cm)/K082065 |
| Max. phase charge | 13 uc | 20.8 uc | 13 uc |
| Max. current Density | 0.0246 mA/cm² | 0.04992 mA/cm² | 0.04875 mA/cm² |
| Max. Average current (RMSA) @500Ω | 50 mA | 80 mA | 50 mA |
| Max. Power Density | 0.00156 Watts/ cm² | 0.00200 Watts/ cm² | 0.001219 Watts/ cm² |
Study Proving Device Meets Acceptance Criteria:
The study described is a non-clinical bench testing and comparison study to demonstrate substantial equivalence to previously cleared predicate devices.
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: Not applicable in the traditional sense of a clinical trial with patient data. The "test set" here refers to the device parameters and performance characteristics which are compared against those of the predicate devices. This involves analyzing the technical specifications and output characteristics of the new device.
- Data Provenance: The data comes from the technical specifications, design documents, and bench testing of the new device (OTC Patch, Model WL-2406) and the predicate devices (WL-2406 K052785, WL-2407 K091757). The document implies the origin is Well Life Healthcare Limited in Taiwan, ROC, the submitter. The data is retrospective in the sense that it relies on existing specifications of cleared devices and new device test results.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts:
- Not applicable. Ground truth, in this context, refers to the established specifications and performance of the predicate devices, as recognized by their previous 510(k) clearances. The evaluation is a comparative engineering assessment, not an expert review of clinical cases.
4. Adjudication Method for the Test Set:
- Not applicable. The "adjudication" is essentially a comparison of the technical specifications and performance data of the new device against the established parameters of the predicate devices, as reviewed by the FDA.
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:
- No. This is a TENS device, not an AI/CADe medical imaging device. Therefore, MRMC studies and "human readers improving with AI assistance" are not relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No. This is a physical device submission; there is no "algorithm only" performance concept here beyond the device's electrical characteristics. The device operates standalone in the sense that it delivers electrical stimulation as programmed without continuous human intervention during therapy, but it is not an AI diagnostic standalone system.
7. The Type of Ground Truth Used:
- The "ground truth" for comparison is the technical specifications, output characteristics, safety standards compliance (e.g., IEC 60601-2-10, IEC 60601-1, IEC 60601-1-2), and intended use of the legally marketed predicate devices.
8. The Sample Size for the Training Set:
- Not applicable. This is not a machine learning or AI device.
9. How the Ground Truth for the Training Set was Established:
- Not applicable. (See #8)
Summary of the "Study" (Non-Clinical Comparison):
The "study" conducted for K133723 is a comprehensive non-clinical comparison study that evaluates the new device against two predicate TENS devices (K052785 and K091757). The core of this study involves:
- Comparison of Intended Use: The new device combines and expands the indications of the two predicate devices, stating temporary relief of pain in "low back as well as upper and lower extremities (arm and/or leg)." This is considered substantively equivalent or a logical extension based on the predicate devices.
- Comparison of Technological Characteristics: Detailed comparison tables (Sections 7, 8, and 9) provide side-by-side analysis of:
- Operational modes and pre-programmed parameters (fixed pulse rate, frequency, timer).
- Output characteristics (waveform, shape, max voltage, max current, pulse duration, frequency).
- Safety features (patient leakage current, isolation, automatic shut-off).
- Physical characteristics (power source, dimensions, materials).
- Electrode type and size.
- Compliance with Voluntary Standards: The device demonstrates compliance with applicable voluntary standards, including IEC 60601-2-10, IEC 60601-1, and IEC 60601-1-2, as well as FDA software guidance. This demonstrates that the device meets recognized safety and performance benchmarks.
- Detailed Calculation Comparison: "Through the detailed calculation comparison of stimulation output energy for each operation model in particular the output current density and power density), we found the output level in each operation mode for our OTC Patch, model WL-2406 and predicate device are very close and within the acceptable range as specified in FDA guidance." This explicitly addresses that despite slight differences in "detailed output parameters (mainly in the pulse duration and electrode sizes)," the overall output energy, current density, and power density are comparable and safe.
- Conclusion of Substantial Equivalence: The study concludes that the new device has "the same intended use and the similar technological characteristics as the cleared devices" and that the "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." Meaning that the engineering differences do not affect intended use or alter the fundamental scientific technology.
This approach is standard for 510(k) submissions where a new device is substantially equivalent to a predicate device, and new large-scale clinical trials are not typically required unless there are significant changes in technology, indications, or safety profiles.
§ 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).