Following the release of the Optical Physiological Bench, we have shipped the next instrument in PiEEG Cloud's scientific recording series: the Oculomotor, Blink & Pupillometry Bench.
Rather than rendering a casual full-face webcam preview, the bench locks onto the medial and lateral canthi of both eyes offscreen (1280×720 at 30 Hz), affine-rectifies head roll to 0°, and isolates only two roll-stabilized periocular scopes (OD · Right Eye and OS · Left Eye) synchronized on a shared monotonic clock with your live PiEEG electrophysiological channels.
Four Transparent Pipeline Stages
Every computer-vision and signal-coupling step is exposed for inspection and CSV/JSON export—never hidden behind opaque scores:
- Pixel-Level Segmentation & Chord Profiling: Switch either eye viewport live between rectified RGB, the per-pixel segmentation overlay (dark pupil core, iris stroma annulus, corneal Purkinje glint exclusion, and eyelid margins), and the 2D Sobel gradient, paired with the 1D horizontal iris chord intensity profile
I(u). - Distance-Invariant Pupillometry & Photic Reflex (PLR): Computes the iris-normalized pupil ratio (
D_pupil / D_iris) with blink hold-last-valid gating and zero-phase Butterworth filtering so head Z-movement and blink occlusions don't masquerade as dilation. Includes a built-in photic step trigger to quantify pupillary light reflex constriction latency, amplitude, peak velocity, andT63recovery alongside occipital alpha reactivity. - Ballistic Blink & Gaze Kinematics: Tracks asymmetric closing versus opening eyelid velocity (
dA/dt), conjugate gaze azimuth/elevation, binocular vergence, and 68% bivariate contour ellipse area (BCEA) fixation stability. - Live Optical-to-Bio L2 Ridge Coupling: Continuously fits standardized L2-regularized regression weights mapping
[eyelidClosure, eyelidVel, gazeAzimuth, gazeElevation]onto each concurrent EEG/EOG channel—reporting per-channelR²and reconstructing the ocular dipole contribution in microvolts in real time.
Open It in PiEEG Cloud
Launch PiEEG Cloud and open Oculomotor, Blink & Pupillometry Bench from the Experiences gallery (including built-in reference PLR validation takes when running without a camera).
