AYUSH MAHAJAN
BRAIN–COMPUTER INTERFACE VENTURE2019—24
Cerebralx / Xone

Turning visual attention into a command a connected device can understand.

I founded Cerebralx and led Xone, a lower-cost brain–computer-interface prototype that captured visual-attention EEG patterns, classified one target from a fixed set, and mapped it to a predefined connected-device command.

For
People and teams exploring alternate, hands-free interaction with connected devices
Ayush owned
Founder and principal engineer; led a multidisciplinary team of roughly ten across hardware and software
Scope
Visual stimulus → dry-electrode EEG → signal processing → SSVEP classification → device command
CONCEPTUAL / XONE / SIGNAL-TO-DEVICE LOOPConcept demo · not a medical device · does not read thoughts
01 / VISUAL ATTENTIONATTEND ONE TARGET FROM A FIXED SET
02 / DRY-ELECTRODE EEGFaint signal + physical-world noise
  1. 01
    ATTENDVisual target
  2. 02
    CAPTUREDry-electrode EEG
  3. 03
    FILTERSignal over noise
  4. 04
    CLASSIFYAttended target
  5. 05
    MAPPredefined command
PREDEFINED COMMAND SETLIGHT / ONCONNECTED DEVICE RESPONDSObservable feedback closes the loop
01 / THE PRODUCT STORY

Before architecture, the workflow.

SITUATION

A conventional interface assumes reliable speech or movement.

The product question was whether lower-cost brain-signal hardware could support another control path: a person focuses on a visual target, the system recognizes the associated neural response, and a connected device receives the intended command.

FRICTION

The signal is faint; the noise is part of the product.

Dry electrodes, constrained electronics, movement, environmental noise, individual variation, real-time processing, and device connectivity all affect whether an apparent signal becomes a dependable command. No single model or hardware component can solve the loop in isolation.

WHAT I BUILT

An end-to-end signal-to-device prototype and venture around it.

I owned the stack across electronics and PCB prototyping, embedded firmware, signal processing, SSVEP decoding experiments, real-time control, and cloud/device integration while coordinating the multidisciplinary team, grants, demonstrations, and stakeholders.

02 / WHAT USING IT FEELS LIKE

The product in human steps.

The default story stays at the level of the person and the work they are trying to finish.

  1. 01
    Choose a visual target

    The interface presents distinguishable visual frequencies tied to possible commands.

  2. 02
    Capture the response

    Dry-electrode EEG hardware records the activity associated with sustained visual attention.

  3. 03
    Clean the signal

    Filtering and signal processing reduce interference before interpretation.

  4. 04
    Classify the attended target

    SSVEP-oriented classification matches the response to one frequency from the fixed target set.

  5. 05
    Control the connected device

    The application sends the chosen command through the embedded and IoT path.

03 / THE DIFFICULT PRODUCT DECISION

Where should the product boundary sit when hardware and signal quality shape every software result?

Across the whole loop. Electronics, firmware, decoding, interface, and device control had to be designed together.

A better classifier cannot recover a signal the electrodes never captured, and better hardware is not useful if the command path feels slow or opaque. The team treated the complete signal-to-action loop as the product rather than optimizing one layer in isolation.

04 / WHAT CHANGED DURING DEVELOPMENT

The work moved from component experiments to an integrated control loop.

BEFORE

EEG acquisition, noise reduction, classification, embedded control, and connected-device behavior could each look promising in isolation.

OBSERVATION

A demonstration failed whenever any boundary between those layers introduced noise, latency, an invalid command, or an integration mismatch.

CHANGE

I led hardware and software iteration as one system: electrode and ADC work informed filtering; decoding constraints informed the interface; firmware and connectivity completed the command path.

RESULTING PRODUCT PRINCIPLE

The durable engineering principle was multidisciplinary: when the input comes from the physical world, product reliability lives between disciplines.

05 / VERIFIED EVIDENCE

What the record supports—and where it stops.

~₹50Lnon-dilutive support

Government-backed support associated with the Cerebralx venture period.

Source
Canonical résumé and master project record
Boundary
Funding support for venture development, not product revenue, sales, or clinical adoption.
~10multidisciplinary team

Ayush founded and led work spanning hardware, embedded systems, signal processing, software, and product.

Source
Canonical résumé
Boundary
Approximate team scale across the venture, not a precise headcount for every development phase.
END-TO-ENDsignal-to-device prototype

The development work included a multiplayer BCI demonstration and connected-device control loop.

Source
Master project record and accepted portfolio evidence
Boundary
Prototype evidence—not clinical validation, medical approval, peer-reviewed efficacy, or commercial release.
06 / OPTIONAL TECHNICAL ROUTE

Architecture is available, not compulsory.

The technical route traces signal acquisition, constrained decoding, connected-device execution, and the publication boundary between a working prototype and a clinically validated device.

FOR TECHNICAL READERSArchitecture, boundaries, failure modes, and verification
T01

One loop from attention to action

The system connects visual stimulus, EEG acquisition, filtering, decoding, embedded control, and device response.

  • Visual stimuli provide known frequencies that can elicit steady-state visual evoked potentials.
  • Dry-electrode EEG and constrained acquisition electronics capture the low-amplitude signal.
  • Signal processing and classification estimate which target the person is attending to.
  • ESP32, firmware, MQTT, and connected-device paths carry the constrained command into an observable action.
T02

The model begins after the measurement problem

Classification quality depends on electrode contact, acquisition, filtering, and the interaction protocol before inference starts.

  • Dry electrodes trade setup convenience against signal consistency and noise sensitivity.
  • ADC behavior, shielding, movement, and environmental interference shape the usable signal.
  • Filtering must preserve the frequencies the decoder needs rather than merely smooth the trace.
  • Constrained command selection is materially different from unconstrained mind-reading or thought reconstruction.
T03

An uncertain signal should not become an arbitrary command

The product must account for weak confidence, calibration variation, connectivity loss, and device-state mismatch.

  • Low-confidence or noisy windows require rejection, retry, or recalibration rather than forced selection.
  • A decoded target still needs validation against the allowed command set.
  • Firmware and network failures must not be confused with unsuccessful neural decoding.
  • Observable device feedback closes the loop so the person can see whether the intended action occurred.
T04

Prototype evidence has a deliberate ceiling

Demonstration, funding, and multidisciplinary implementation do not establish clinical performance.

  • The end-to-end prototype and multiplayer demonstration establish integrated development work.
  • Approximately ₹50 lakh in non-dilutive support establishes external backing for the venture period.
  • The route does not publish accuracy, medical efficacy, diagnostic, or hospital-use claims.
  • Exploratory SDK, XR, and reconstruction ideas are not presented as shipped Xone capabilities.
TECHNOLOGY CONTEXT

The implementation followed the product boundary.

  • EEG / SSVEP
  • Dry electrodes
  • ESP32
  • PCB / electronics
  • Signal processing
  • Python / ML
  • Firmware
  • MQTT
07 / WHAT THIS PROVES FOR A CLIENT

This work shows I can lead products whose hardest problems cross hardware, software, signal processing, real-time systems, team coordination, and the practical work of turning research into a demonstrable loop.

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