IDUN Guardian 4: The next-generation brain-sensing platform, built to scale

Your smartwatch knows your heart rate. It counts your steps. It estimates when you fell asleep and tries to guess how well you slept. It infers your stress levels from heart rate variability. But there's one thing it can't do: actually measure what's happening in your brain.

This isn't a minor limitation—it's the fundamental constraint of modern wearables. Every metric your favorite wearable provides is an indirect inference, a proxy signal from your periphery that tries to work backward to understand what your brain is doing. It's like trying to understand a conversation by watching shadows on a wall instead of listening to the speakers.

For decades, the only way to directly measure brain activity was in a lab, with gel, a technician, and equipment that required you to sit perfectly still. The promise of real-world brain sensing seemed impossibly far away.

IDUN Guardian 3 proved that promise was within reach. Over the past years, research partners used it to study sleep architecture, measure cognitive workload, detect driving fatigue, and test closed-loop neurofeedback protocols, all with a device people could use outside a lab setting.

Now, we are excited to take to the stage of CES to unveil the IDUN Guardian 4, making the next step from proof-of-concept to practicality: growing from a research device into a scalable platform ready for the applications that will define the next decade of neurotechnology.

The Brain-Sensing Platform We've Been Waiting For

When we set out to design IDUN Guardian 4, we had a clear mandate: this couldn't just be "3 with improvements." We needed to build an operating system for the brain—a platform that could support real-time neuroadaptive applications at scale.

This meant rethinking everything—from how we capture neural signals to how we process them on-device to how we enable applications to respond to cognitive state in real-time.

Four core capabilities define IDUN Guardian 4:

1. An Operating System for the Brain: IDUN Guardian 4 provides a complete software and hardware platform that transforms raw EEG signals into actionable insights and real-time interactions. Like any OS, it handles the complexity underneath—signal acquisition, noise filtering, feature extraction, classifier execution—so applications can focus on what matters: responding intelligently to brain states. For OEM partners, we offer flexible integration options that can be tailored to specific product requirements.
2. Cleaner Brain Signals: The Analog Devices (ADI) front-end amplifier delivers improved noise performance, higher signal stability, and robust frequency features. IDUN Guardian 4 handles real-world motion, extended wear, and diverse users without compromising EEG quality during daily activities like walking, talking, working out, and commuting.
3. A True Brain-Sensing Earbud: Thanks to the Qualcomm Snapdragon S7 Sound platform, IDUN Guardian 4 provides audio and voice functionality alongside brain sensing.
4. On-Device Processing: Edge capabilities introduce DSP-based classifiers with future support for ML models running directly on the device. This provides lower latency, offline use cases, and entirely new brain-computer apps like neuroadaptive audio that responds to your cognitive state in real-time.

What this actually means: A Concrete Example

Let's make this tangible. Imagine you're listening to music during your morning commute. Your attention starts to drift—maybe you're tired, maybe the cognitive load of navigating a crowded train is overwhelming, maybe you're just not in the mood for high-tempo electronic music right now.

With IDUN Guardian 4, your device knows; not because it's guessing based on your heart rate, but because it's directly measuring your brain's response to the audio stimulus through continuous EEG sensing.

The device processes this information locally—no cloud round-trip, no latency, no privacy concerns about sending your brain data off-device. This opens up exciting possibilities like adjusting equalizer settings, shifting playlists, or modulating audio characteristics to match your cognitive state—neuroadaptive audio that responds in real-time.

This is hands-free interface control driven by your actual brain activity. No voice commands, button presses, or interruption to your experience. Just technology that responds to your neural state as naturally as your pupils respond to changing light. IDUN Guardian 3 couldn’t do it, but thanks to its improved comfort, on-device processing, and superior signal quality, IDUN Guardian 4 can.

Comfort as an Unlock

There's a reason traditional EEG requires gel, skilled technicians, and patient cooperation: getting clean electrical signals from the brain through the skin, skull, and tissue is genuinely difficult. Small movements, poor electrode contact, or unstable impedance can ruin signal quality.

IDUN Guardian 3 made this workable. IDUN Guardian 4 makes it comfortable enough for everyday use.

Brain sensing starts with high-quality electrodes. The IDUN Dryode® sensor is a soft and conformable ear tip sensor that looks and feels like a normal earbud ear tip, but is also conductive and can sense electrical brain signals.

The new Dryode® ear tip, refined mechanical structure, and improved wing design create more consistent electrode-skin contact while reducing pressure points. The difference isn't subtle—during testing across sleep, motion, commuting, and extended wear scenarios, users consistently reported faster setup times, better sustained comfort, and fewer adjustments needed during use.

This matters because comfort isn't a luxury feature in brain sensing—it's a fundamental requirement. The most sophisticated signal processing in the world can't fix an electrode that isn't making consistent contact because the user adjusted the device to relieve discomfort.

Validation to Match our Ambition

Moving from a research device to a scalable platform ready for a broader ecosystem of applications and partners requires more than engineering improvements—it requires a validation framework rigorous enough to support the claims we're making.

We developed the IDUN Guardian 4 Validation Framework specifically for this transition, used consistently across testing partners and internal engineering teams:

1. Pre-Validation: Study coordination ensures alignment on signal requirements, relevant literature, and partner use-cases before testing begins—no guessing about whether we're measuring the right things.
2. Hardware Validation: Focus on baseline hardware performance: signal stability, impedance behavior, and frequency-based EEG metrics benchmarked directly against IDUN Guardian 3's validated performance.
3. Algorithm Validation: Evaluate real-time classifiers, eye direction and jaw activity in both offline and on-device environments, tuning models for optimal performance.
4. Application Validation: Test complete end-to-end use cases—sleep tracking, cognitive load measurement, gesture-based interfaces—with direct comparisons to IDUN Guardian 3.
5. Documentation: Consolidate results into structured reports that partners can use for their own internal evaluation, product planning, and integration decisions. This transparency is critical: if IDUN Guardian 4 is going to serve as a platform, developers and researchers need confidence that their investment will be built on solid ground.
   
   

Backward-Compatible, Forward-Looking

Importantly for our existing partners: despite these architectural changes, IDUN Guardian 4 remains fully backwards compatible with workflows designed for IDUN Guardian 3.

Your existing applications work. Your SDK calls work. Your data formats work. No forced migration, no rewriting, no disruption.

At the same time, new capabilities including audio integration, on-device inference, sub-4ms timestamp synchronization, enhanced impedance monitoring provide room for innovation without breaking what's already working.

This balance is deliberate. Platform thinking means respecting the investments people have already made while creating space for what comes next.

The Roadmap This Enables

IDUN Guardian 4's platform architecture provides a clear evolution path, building on the software and hardware foundation we're unveiling at CES. This includes edge processing that enables real-time neurofeedback, neuroadaptive audio, gesture-free interfaces and brain-computer interactions that work in the real-world outside of research labs.

What Comes Next

The history of consumer wearables to this point has been one of gradually perfecting biosensors at the periphery, measuring what happens around your brain: your heart, your movement, your skin temperature, your blood oxygen.

The IDUN Guardian 4 is designed for what comes next: direct brain sensing that's comfortable enough for daily use, powerful enough for real-time interaction, and rigorously validated to support serious applications. It makes practical what IDUN Guardian 3 made possible.

The final frontier of consumer wearables isn't smaller sensors or longer battery life. It's accessing the organ that actually generates the experiences those other metrics can only infer: your brain.

This January 6-9, join us and our partner ADI at CES as we set out for that final frontier, together. You can book to meet us right here: Meet us at CES 2026