(260 days)
Stivax is an electro-acupuncture device for use in the practice of acupuncture by qualified practitioners of acupuncture as determined by the states.
The Stivax is a single use, battery-powered, electrical nerve stimulator which is used for the stimulation of the vagus nerve via the ear. The device connects an electrode cable to two sterile (radiation) acupuncture needles that have been applied by a healthcare practitioner. The stimulator connects to a clip holder on medical grade adhesive tape. The stimulator (with tape) adheres to the patient, behind the ear.
The STIVAX and the sterile (radiation) stimulation double needle are intended for single use.
The device consists of the stimulator and a stimulation double needle. The device cannot be recharged. The device has no connection to any external devices except the electrode.
The stimulator is housed in plastic. It is connected through a plug to the stimulation double needle (needles made of titanium, insulated wire). The power is supplied by a 3 V battery (type CR1220).
The dimensions of the device are W x H x D 34 x 7 x 20 mm, the weight is 4.41 g with battery.
The device is activated by connecting the stimulation double needle.
This document is a 510(k) premarket notification for the Stivax System, an electro-acupuncture device. The core of this submission is to demonstrate substantial equivalence to a predicate device, the Biegler P-Stim System (K140788), rather than proving the device meets specific acceptance criteria through a clinical study. Therefore, most of the requested information regarding acceptance criteria and performance studies for an AI/algorithm-based device is not directly applicable or available in this document.
However, I can extract the information that is present concerning the device's technical specifications and the non-clinical testing performed for its substantial equivalence claim.
Here's the breakdown based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't present "acceptance criteria" in the typical sense for an AI/algorithm where specific metrics (e.g., sensitivity, specificity) are defined and then performance against those metrics is reported. Instead, it relies on demonstrating that the subject device (Stivax) has equivalent or comparable specifications and performance to its legally marketed predicate device (P-Stim).
| Feature | Acceptance Criteria (Implied by Predicate) | Reported Stivax Performance (Comparison to Predicate) |
|---|---|---|
| General Characteristics | The Stivax System is described as a single-use, battery-powered, electrical nerve stimulator for vagus nerve stimulation via the ear, similar in principle to the predicate. It connects an electrode cable to two sterile acupuncture needles. The stimulator (with tape) adheres to the patient, behind the ear. Dimensions: 34 x 7 x 20 mm, Weight: 4.41 g. | |
| Power Source | 3x 1.4 V zinc-air batteries (Predicate) | 3 V battery (CR1220) |
| Output Modes | 1 (Predicate) | 1 |
| Output Channels | 1 (Predicate) | 1 |
| Waveform | Biphasic (Predicate) | Monophasic (Difference noted, but deemed not to raise new safety/risks. Deemed substantially equivalent.) |
| Waveform Shape | Rectangular (Predicate) | Rectangular |
| Maximum Output Voltage | Variable, e.g., 2.74 V (500 Ω), 3.75 V (10 kΩ) for Predicate | Variable, e.g., 0.56 V (500 Ω), 8.40 V (10 kΩ) (The Stivax has a different maximum output voltage and current profile compared to the predicate, with a lower current for constant current stimulation, which is deemed acceptable.) |
| Maximum Output Current | Variable, e.g., 5.52 mA (500 Ω), 0.38 mA (10 kΩ) for Predicate | Variable, e.g., 1.12 mA (500 Ω), 0.84 mA (10 kΩ) (The Stivax has a constant current stimulation with a lower maximum output current than the predicate, considered acceptable because "constant current stimulation allows us to use a lower maximum output current.") |
| Maximum Phase Charge | 3.31 µC (500 Ω) for Predicate | 0.224 µC (500 Ω) |
| Contact Area (needle electrode) | 1.898 mm² (1 needle) for Predicate | 3.796 mm² (2 needles x 1.898 mm²) (Difference in electrode configuration, but deemed not to raise new safety/risks. Deemed substantially equivalent.) |
| Maximum Current Density | 0.97 mA/mm² (500 Ω) for Predicate | 0.59 mA/mm² (500 Ω) |
| Pulse Duration | 1 ms (Predicate) | 200 µs (Difference noted, but deemed acceptable as "200 us is enough to deliver the energy.") |
| Maximum Average Current | 5.52 mA (500 Ω) for Predicate | 1.12 mA (500 Ω) |
| Maximum Power Density | 2.66 x 10⁻³ W/mm² (500 Ω) for Predicate | 0.33 x 10⁻³ W/mm² (500 Ω) |
| Frequency (Hz) | 1 Hz (Predicate) | 1 Hz |
| Timer Range | Fixed 3 h on / 3 h off (Predicate) | Fixed 40 min on / 20 min off (Difference noted based on "user feedback suggested that the shorter pause of 20 min is less disruptive to the user when they are sleeping." Deemed not to raise new safety/risks and substantially equivalent.) |
| Indication Display | No status indicators (Predicate) | No status indicators (e.g., On/Off, low battery, voltage/current, etc.) |
| Microprocessor Control | Yes (Predicate) | Yes |
| Electrode Cable | Yes (Predicate) | Yes |
| Compliance with Standards | AAMI ANSI ES6060-1 and IEC 60601-1-2 (Predicate) | Stivax complies with AAMI ANSI ES6060-1, IEC 60601-1-2, AND IEC 60601-2-10 (for electrical stimulators). |
| Materials | Identical titanium alloy patient contact needles. Similar medical tape to affix the device. (Implied similarity to predicate) | Materials inclusive of patient contacting materials of the Stivax system are similar to the predicate. The patient contact needles are of identical titanium alloy. A similar medical tape is used to affix the device. |
| Basic Safety and Essential Performance | Met all requirements and specifications (through non-clinical testing against standards and internal specifications) | Verification Testing to ensure the device meets its specifications. Testing of hazard mitigations. Testing for compliance to AAMI ANSI ES60601-1, IEC 60601-1-2, and IEC 60601-2-10. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
No test set for evaluating algorithm performance (clinical or otherwise) is mentioned. This is a medical device 510(k) submission, not an AI/ML algorithm submission that requires such a test set. The submission relies entirely on non-clinical (bench) testing and comparison to a predicate device.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not applicable. No ground truth establishment by experts for an algorithm's performance is mentioned.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not applicable.
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.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
Not applicable. The "ground truth" here is compliance with electrical safety and performance standards, and comparison to the predicate device's established safety and effectiveness.
8. The sample size for the training set:
Not applicable. This device is a hardware electrical stimulator, not an AI/ML algorithm requiring a training set.
9. How the ground truth for the training set was established:
Not applicable.
N/A