(143 days)
ASCEND is intended for use as a transcutaneous electrical nerve stimulation device for temporary relief of pain associated with sore and aching muscles in the lower extremities due to strain from exercise or normal household and work activities.
ASCEND is intended for use as a transcutaneous electrical nerve stimulation device for the symptomatic relief and management of chronic intractable pain.
The device may be used during sleep. The device is labeled for use only with compatible NeuroMetrix electrodes.
ASCEND is a single output-mode transcutaneous electrical nerve stimulator for symptomatic relief and management of chronic intractable pain that is available over the counter. The device utilizes a microprocessor running embedded software to control a high-voltage circuit that generates currentregulated stimulating pulses with specific technical characteristics including pulse shape, amplitude, duration, pattern, and frequency. The device is powered by an embedded rechargeable Lithium-Ion battery that is charged through a USB cable connected to an AC adapter.
The device delivers electrical stimulation to the user through disposable electrodes placed on the user's body. The device is labeled for use only with compatible NeuroMetrix electrodes (e.g. SENSUS Electrode, K121816), to which it connects through insulated female medical snap connectors embedded within its housing; no lead-wires are used. Compatible NeuroMetrix electrodes are comprised of four individual hydrogel pads arranged in a linear array. The hydrogel pads are electrically connected in pairs such that the two outer hydrogel pads constitute one electrode and the two inner hydrogel pads constitute a second electrode. The user interface consists of a push button and a two-color LED. The push button initiates and controls stimulation intensity. The LED indicates stimulation status, battery charging, and error conditions.
Here's a breakdown of the acceptance criteria and study as described in the provided 510(k) summary for ASCEND™:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| At least 80% of participants successfully completed all five basic device tasks (checking battery, placing device and configuring, starting a therapy session, modifying stimulation intensity, and stopping a therapy session) based on reading and following the directions for use. | 86.2% of participants successfully completed all five tasks (25 out of 29 participants). The lower bound of the 95% confidence interval (68.3%) was not explicitly stated to meet the 80% threshold but the upper bound of 96.1% exceeded 80% and the null hypothesis that the true pass rate was ≥ 80% could not be rejected. |
Details of the Usability Study
2. Sample size used for the test set and the data provenance:
- Sample Size: 29 participants.
- Data Provenance: The study was a prospective usability study, likely conducted in the US where NeuroMetrix, Inc. is located. The document does not explicitly state the country of origin, but given the sponsor's address.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The study was a usability study focused on whether untrained users could operate the device based on its labeling. Therefore, the "ground truth" was the objective successful completion of predefined tasks by these users, not an expert assessment of a medical condition. No experts were used to establish ground truth in the traditional sense of medical diagnosis.
4. Adjudication method for the test set:
- Not applicable in the context of a usability study where success is objectively measured by task completion by the participants themselves.
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 MRMC comparative effectiveness study was done. This study was a usability study for an over-the-counter transcutaneous electrical nerve stimulator (TENS) device, not an AI-powered diagnostic tool.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. The device is a TENS unit, and the study was a human usability study.
7. The type of ground truth used:
- The "ground truth" for this usability study was the objective successful completion of specific device-operation tasks by study participants, as outlined in the device's labeling (instructional video and quick start instructions). It was not based on expert consensus, pathology, or outcomes data related to disease diagnosis or treatment efficacy, but rather on the ability of lay users to correctly operate the device.
8. The sample size for the training set:
- Not applicable. This was a usability study, not a machine learning model development study, so there was no "training set."
9. How the ground truth for the training set was established:
- Not applicable. As noted above, there was no training set for a machine learning model.
§ 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).