(277 days)
The Well-Life OTC EMS System / model no. WL-2412(A) is intended for use by healthy adults for the stimulation of healthy muscles in order to improve or facilitate muscle performance.
The Well Life OTC EMS System, model no. WL-2412(A) is intended for use by healthy adults for the stimulation of healthy muscles in order to improve or facilitate muscle performance; it is not intended as a therapy for any medical condition. Basically the model WL-2412(A), powered by 4.5V (3xAAA/Alkaline battery), is muscle stimulation device and identical to the SE predicate device - Slendertone EnerVive, Type 561, vith the following features:
- It is a portable two-channel, battery operated neuromuscular electronic stimulation system.
- It contains 6 programs as the predicate device; the output waveform is selectable pre-programming change among P1~P6
- The output strength is adjustable at 0
80mA via requlated voltage, with variable setting time 560 minutes counting from switching ON. - The LCD display is provided for the indication of operation status including operation mode, output program mode, output intensity, time to cut-off, and battery low indication.
- The device uses exactly Ultrastim Electrode (K000947) same as predicate device, providing as stimulation transmission media.
The provided text describes a 510(k) summary for the Well-Life OTC EMS System, model WL-2412(A). It establishes substantial equivalence to a predicate device, the Slendertone EnerVive 561 (K071666). The approval process for this device did not involve typical "acceptance criteria" and a "study proving the device meets the acceptance criteria" in the way a diagnostic or treatment algorithm would. Instead, the focus is on demonstrating that the new device has "the same safety and effectiveness" as a legally marketed predicate device through technical comparison and compliance with standards.
Here's a breakdown based on the information provided and what can be inferred for a 510(k) submission:
1. Table of Acceptance Criteria and Reported Device Performance
For this type of device and submission, the "acceptance criteria" and "reported device performance" are primarily based on the comparison to the predicate device and adherence to established standards. There aren't specific numerical performance metrics in the way a diagnostic algorithm (e.g., sensitivity, specificity) would have. The criteria are related to maintaining fundamental technological characteristics and safety/effectiveness.
| Acceptance Criteria (Implicit for Substantial Equivalence) | Reported Device Performance (Well-Life OTC EMS System WL-2412(A)) |
|---|---|
| Intended Use Equivalence: Same intended use as predicate. | "The Well-Life OTC EMS System / model no. WL-2412(A) is intended for use by healthy adults for the stimulation of healthy muscles in order to improve or facilitate muscle performance," which is the same as the predicate. |
| Technological Characteristics Equivalence: Similar fundamental technological characteristics to predicate. | See detailed comparison table below. Minor differences in voltage and current at specific resistances are within acceptable deviation ranges (±20%). |
| Safety and Effectiveness Equivalence: No new safety or effectiveness concerns. | The submission states that "the WL-2412(A) could maintain the same safety and effectiveness as that of cleared device." |
| Compliance to Applicable Standards: Adherence to relevant voluntary standards. | Compliance to ANSI/AAMI NS4-1985, EN 60601-1, and EN 60601-1-2. Software verification carried out according to FDA guidance. |
Detailed Comparison of Technological Characteristics (from text):
| Attribute | Predicate Device (EnerVive 561, K071666) | Well-Life OTC System (WL-2412(A)) | Discussion of Difference (implicitly accepted if "Same" or within tolerance) |
|---|---|---|---|
| Design | Muscle Stimulator | Muscle Stimulator | Same |
| Size | 104×63.4×30 mm | 90×52.5×18.9 mm | (No specific acceptance criteria listed for size, considered non-critical) |
| Waveform | Symmetrical biphasic square | Symmetrical biphasic square | Same |
| Channels | Dual | Dual | Same |
| Power supply | 9V | 4.5V | Same (likely referring to the function of power supply, not voltage) |
| Material (Unit Housing) | ABS plastic | ABS plastic | Same |
| Number of Self-Adhesive Electrodes | 2 pairs of butterfly gel pads type 719 | 2 pairs of ULB 355 | Same supplier; 510(k) K000947 cleared |
| Nos. of Programs | 6 | 6 | Same |
| Amplitude (mA) | 0~80 | 0~80 | Same |
| Pulse rate (Hz) | 4~99 | 4~99 | Same |
| Pulse width (µS) | 200~300 (also listed below as 200-300) | 200~300 | Same |
| Frequency (Hz) | 4-99 | 4-99 | Same |
| Maximum Phase charge (µC) @500Ω | 28.4 | 28.4 | Same |
| Maximum Current Density (mA/cm²) @500Ω | 0.1485 | 0.1485 | Same |
| Maximum Power Density (W/cm²) @500Ω | 0.00594 | 0.00594 | Same |
| RMS Voltage (RMSV) (±20%) @ 500Ω | 7.5V | 8.8 V | Max. deviation 17.3%, within acceptable |
| deviation range (±20%). | |||
| RMS Voltage (RMSV) (±20%) @ 1KΩ | 12.5V | 11.7V | Within acceptable deviation range (9.6%) |
| RMS Voltage (RMSV) (±20%) @ 1.5KΩ | 13.7V | 13.8V | Within acceptable deviation range (1.1%) |
| RMS Voltage (RMSV) (±20%) @ 2kΩ | - | 16.3V | (New point for WL-2412A) |
| RMS Voltage (RMSV) (±20%) @ 10kΩ | - | 27.2V | (New point for WL-2412A) |
| RMS Current (RMSA) (±20%) @ 500Ω | 15mA | 17.6mA | Within acceptable deviation range (17.3%, derived from voltage deviation) |
| RMS Current (RMSA) (±20%) @ 1KΩ | 12.5mA | 11.7mA | Within acceptable deviation range (9.6%) |
| RMS Current (RMSA) (±20%) @ 1.5kΩ | 9.1mA | 9.2mA | Within acceptable deviation range (1.1%) |
| RMS Current (RMSA) (±20%) @ 2kΩ | - | 8.15mA | (New point for WL-2412A) |
| RMS Current (RMSA) (±20%) @ 10kΩ | - | 2.72mA | (New point for WL-2412A) |
| Prescription or OTC | OTC | OTC | Same |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document primarily relies on non-clinical tests (comparison of specifications and compliance with standards) rather than clinical studies with patient test sets. Therefore, there is no sample size for a test set in the traditional sense of patient data. The "testing" involved verifying the new device's specifications against those of the predicate and against engineering standards. The data provenance is from the device manufacturer (Well Life Healthcare Limited in Taiwan) and relates to their internal testing and comparison. The nature of these tests is not explicitly stated as retrospective or prospective in the context of patient data, as it's primarily engineering verification.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. As noted above, there isn't a "test set" of patient data requiring expert ground truth in this 510(k) submission. The ground truth for this submission is based on engineering specifications and adherence to recognized standards for electrical medical devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. There is no adjudicated test set of clinical 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 muscle stimulator, not an AI-powered diagnostic or interpretation tool that would involve human readers.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. This is a hardware medical device with pre-programmed settings, not an algorithm.
7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)
The "ground truth" for this 510(k) submission is the engineering specifications of the predicate device and the new device, along with established international and national standards (e.g., ANSI/AAMI NS4-1985, EN 60601-1, and EN 60601-1-2) for the safety and performance of powered muscle stimulators. The verification and validation tests confirmed that the WL-2412(A) met the technical requirements and maintained safety and effectiveness comparable to the predicate.
8. The sample size for the training set
Not applicable. This being a hardware muscle stimulator, there is no "training set" in the context of machine learning or AI.
9. How the ground truth for the training set was established
Not applicable. As there is no training set.
§ 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).