EverSteady™ Stimulation Platform
The science behind sessions that work
The current-controlled engine inside every clinical Vagal stimulator. 50,000 adjustments per second ensure every pulse reaches your vagus nerve with precision.
Precision Engineered for Your Nervous System
EverSteady is Vagal's proprietary current-controlled stimulation platform. Unlike voltage-controlled TENS devices that push a fixed voltage and hope for the best, EverSteady continuously measures your skin's electrical properties and adjusts its output to deliver exactly the current you set.
Your skin is a living organ. Its impedance changes with temperature, hydration, sweat, even time of day. EverSteady adapts to all of it, 50,000 times per second, ensuring the therapeutic dose reaching your vagus nerve stays constant from the first second to the last.
See how this compares to voltage-controlled devicesThe EverSteady Feedback Loop
Measure Impedance
The stimulator reads your skin-electrode resistance in real time. This value changes constantly as you move, warm up, or perspire.
Calculate Voltage
Using Ohm's law (V = I x R), the processor determines the exact voltage needed to deliver your target current through the measured resistance.
Deliver Pulse
A precise biphasic square wave is generated. The positive phase stimulates; the negative phase reverses the charge, protecting tissue.
Repeat 50,000x/sec
This entire loop runs continuously. Every pulse is individually calibrated. No spikes, no decay, no drift.
What Makes EverSteady Different
Three engineering principles working together to deliver stimulation your nervous system can rely on.
Current Control
The device regulates current, not voltage. Your set intensity is the intensity delivered, regardless of skin impedance changes. No spikes, no decay.
Charge Balance
Every pulse is biphasic: an equal and opposite phase follows each stimulation phase. This ensures zero net charge accumulates in tissue, maximising safety.
Protocol Flexibility
EverSteady isn't locked to one frequency. Load custom stimulation protocols via the Vagal Tones app or the Tone Research Portal. The precision engine adapts to any waveform.
The EverSteady Modes
Current control is the foundation. These four modes sit on top of it, each solving a specific problem that shows up once you actually use a stimulator day after day.
Auto Wear Detection
The device senses when it is correctly placed in your ear and begins your session on its own. No unlocking your phone, no opening the app, no hunting for a button. Put it in, and it starts.
Adapt Anti-Habituation
Your nervous system tunes out signals that never change. Adapt introduces controlled variation within limits you set, so a long session stays as effective at minute forty as it was at minute one. We recommend 8 to 12 percent for most people.
Pulse+ Impedance Boost
Skin behaves like a capacitor, blunting the leading edge of every pulse. Pulse+ widens the pulse to push through that capacitive effect, so the charge your nerve actually receives matches the charge you asked for.
Switch Duty Cycle Control
Not everyone responds to the standard on-off cycling pattern. Switch lets you move between standard, rapid and saturation duty cycles, following the 415-patient Norwegian study that found non-responders often do better on an alternative cycle.
The EverSteady Control Range
Every parameter below is addressable from the Vagal Tones app and the Tone Research Portal. This is the same control surface our research partners use to build and publish custom protocols.
This is the full control envelope of the EverSteady platform. The range available to you depends on your device and firmware version, and the app keeps you inside safe limits for consumer use.
Explore the Tone Research PortalWhich Devices Include EverSteady?
EverSteady is built into our clinical-grade stimulators. Our entry-level Vagal Boost uses standard voltage-controlled tENS technology instead, making it an affordable way to try vagus nerve stimulation before upgrading.
- Current-controlled precision
- Completely wireless
- App-controlled protocols
- Over-the-air firmware updates
- Current-controlled precision
- 15 intensity levels
- 3 built-in plus loadable tones
- EverCharge wireless charging
- Voltage-controlled (standard tENS)
- Phone-powered via USB-C
- 6 stimulation modes
- Full refund credited toward upgrade
Does not include EverSteady. Upgrade to Oh! or Buddy for current-controlled precision.
Why Precision Stimulation Matters
Your vagus nerve contains approximately 100,000 individual fibres, each with different activation thresholds. Myelinated A and B fibres respond to lower currents; unmyelinated C fibres require different parameters entirely. Delivering the wrong current means activating the wrong fibres, or no fibres at all.
EverSteady ensures the current you set is the current delivered. Combined with the protocol flexibility of the Vagal Tones app, this means you can target specific therapeutic outcomes with repeatable precision, session after session.
Learn about vagus nerve fibre types