Explore how wearable sensors capture the body in motion. Control the runner to see how ECG, EMG, PPG, and EEG respond to exercise, and how movement affects signal quality.
HOLD → TO RUN
←→BRAKE / RUN
These four signals are synthetic and physiologically informed, not human recordings, and time is compressed. They share one model of speed, cadence, gait phase and heart rate. Cadence and motion artifact respond quickly to speed, heart rate lags. Hamstring bursts follow the stride cycle, and artifacts sit at the step rate and its harmonics, as in wearable and mobile EEG recordings. Amplitudes, the EEG rhythms and the exact timings are illustrative. Methods & Validation
01Bio
Eighteen years of ballet made Evangelia curious about how the brain runs the body.
After years of competitive training, that curiosity led her to neuroscience at the University of Michigan and now a master's in neural engineering at Columbia. Her work sits at the intersection of neural and physiological sensing, signal processing, machine learning and human movement, with experience in EMG, gait analysis and wearable technology.
As a personal trainer, she sees the challenge of translating science into practice firsthand. Advanced sensing technology is still concentrated in research and clinical settings, while consumer wearables are accessible but rely on generalized metrics that miss individual differences and rarely turn measurements into personalized insight.
Her ambition is to bridge that gap with intelligent technology that combines neural and physiological sensing, signal processing and machine learning to understand and ultimately enhance how the brain and body function, communicate and adapt. Because every person has a unique physiological baseline, she envisions technology that goes beyond monitoring to help people understand their own physiology, overcome limitations and expand their capabilities, in health and in performance.
Ballet18+ years
Half marathonJuly 2026
HYROXin training
Off the clockdrawing, painting, travel
02Education
In progress
Columbia University
M.S. Biomedical Engineering, Neural Engineering
Expected December 2026
Dean's M.S. Academic Excellence Fellow
Coursework
Computational Neuroscience
Multimodal Neuroimaging
Deep Learning for Biomedical Signal Processing
Signal Processing for Medical Devices
Computational Modeling of Physiological Systems
Biomedical Innovation (including medical device regulation)
Stem Cell and Genome Engineering
Tissue Engineering
Applied Linear Algebra
Graduated
University of Michigan
B.S. Neuroscience B.S. Modern Greek Language and Literature
August 2024
University Honors. Carrie Arbour Scholarship. N2N Neuropsychology Prize. Vasilis Lambropoulos Modern Greek Translation Prize.
Coursework
Cellular and Molecular Neuroscience
Molecular Basis of Neurological Disease
Behavioral Neuroscience
Human Neuropsychology
The Visual System
Research Methods in Brainwave Recording
Human and Animal Physiology
Biochemistry
Genetics
Statistics and Data Analysis
Programming and Data Structures (EECS 280)
Elementary Programming Concepts (EECS 183)
Abroad
University of Athens, Advanced Modern Greek, C1 (2024) American College of Thessaloniki, Ancient Greek Art and Architecture (2023)
Languages
English and Greek (bilingual). French and Spanish (intermediate). Some Italian and German.
03Experience
September 2026 to presentTeaching assistant
Cellular and Molecular Neurobiology, Columbia University
Supports a 100+ student course with weekly office hours, exam proctoring and concept guides on neuronal electrophysiology, synaptic transmission and sensory systems.
June 2026 to presentResearch assistant
ROAR lab, Columbia University
Robotics and Rehabilitation Laboratory
Built a Random Forest gait classifier in Python on 12,000+ strides from 24 subjects (53.5% baseline accuracy across 11 walking conditions, before separating overground and treadmill walking, leave-one-subject-out cross-validation).
Cleaned and validated 13,500+ stride records and is now separating overground and treadmill walking.
Helps collect wireless surface EMG during biceps curls, comparing free weights with cable-driven robotic assistance.
February 2026 to presentPersonal trainer
Grind House Manhattan
60-minute cross-training sessions
Designs and leads individualized sessions using biomechanics, joint torque and exercise physiology.
Reads wearable metrics (HRV, resting heart rate, sleep, training load) to set intensity and recovery, and sees where today's fitness technology falls short.
January 2025 to presentLeadership
Information Technology Director
National Hellenic Student Association of America
Manages the website for a national student organization, with 7,600+ page views over 316 days.
April to September 2023Internship
Programming Intern, Evercore Technology Partners
Developed full-stack web applications in PHP and Laravel with automated testing across two client projects.
Runner and biosignal simulation: methods, checks and limits
The four traces on the portfolio home page (ECG, EMG, PPG, EEG) are synthetic. They come from one shared physiological state, so heart rate, gait, muscle activity and motion artifact stay consistent with each other. This page states what is modelled, what was tested, and what is simplified. It is a physiologically informed educational simulation. It has not been validated against experimental human recordings and is not a clinically validated model.
Scope
The simulation is an illustration of how movement changes wearable signal quality. It is not a physiological model for estimating anything, and no real recordings are used. Amplitudes are in arbitrary display units.
Model structure
Shared state. Speed drives exercise intensity (slow lag), cadence and motion intensity (fast lag), and a heart-rate state split into a fast and a slow component. Every channel reads this state.
ECG. P, QRS and T built from Gaussians. QRS width is fixed in time, T timing scales with √RR. Respiratory baseline, step-rate sway, electrode-motion resonance and muscle noise are added.
PPG. A pulse that follows the R wave by a simulated pulse arrival delay (pulse arrival time, PAT) that shortens with exercise. PAT includes the cardiac pre-ejection period as well as vascular transit time, so it is not pulse transit time alone. The model delay (about 220 ms at rest to 180 ms at full exercise to the pulse start) is a design value in the range reported for resting PAT, not a fitted result, plus arm-swing, impact, drift and slip artifacts at the measurement stage.
EMG. 20–90 Hz noise shaped by a gait-phase envelope. The main burst falls in late swing into early stance, which is the supported pattern for the biceps femoris long head. Two smaller bursts (late stance, and early swing when running) are illustrative simplifications added for visual realism. No cited source here supports them as universal, and their amplitude is kept low.
EEG. Neural part (≈10 Hz mu rhythm, beta, 1/f background) and artifact part (footstep kicks, cable sway, scalp muscle) are generated separately, which is what allows the annotation "MOTION > NEURAL SIGNAL".
Runner. Knee, hip and foot angles are drawn from gait kinematics. Background scroll speed equals the stance-foot speed.
Sampling
All four channels are generated at 250 Hz of simulated time and drawn in a 7 s rolling window (1750 samples) with a 1 s grid of 250 samples. A real-time accumulator advances the model in fixed 4 ms steps, so scroll speed and the grid stay tied to simulated time whatever the screen's frame rate. The R-wave phase is stored in a ring buffer so the PPG can look up the cardiac phase from one pulse arrival delay earlier. Random noise uses a seeded generator, so a run is repeatable. In the page, measured output through every stage change was 249.4 to 251.1 samples per second.
Automated Simulation Checks: 40/40 Passed
These checks test internal consistency (do the channels agree with each other and with the model's own rules) and physiological plausibility (are values in sensible ranges and trends). They are not validation against experimental human recordings. Each result below is computed from samples the simulation generates.
Check
Result
R-R interval equals displayed heart rate at rest, walk, jog, hard
difference under 1.5 bpm; at 139 bpm R-R is 432 ms, at 105 bpm 572 ms
PASS
R-R variability falls as intensity rises
rest > walk > hard
PASS
ECG peaks coincide with simulated R events
max offset under 12 ms (4 ms sample period)
PASS
QRS width and amplitude independent of heart rate
71 ms and 0.99 at R-R 940, 600, 360 ms
PASS
T-wave timing shortens as R-R shortens
T peak 262, 209, 162 ms after R
PASS
PPG maximum upslope arrives after the R wave, same rhythm
150–300 ms (measured to max upslope, which is later than the pulse foot), pulse period equals R-R
PASS
EMG main burst precedes ipsilateral heel strike; one complex per stride; quiet at contralateral strike
walk, jog, hard
PASS
EMG amplitude rises less than proportionally with speed
hard vs walk under 4× for 4× speed
PASS
EMG power is high frequency
5% below 15 Hz, 95% above
PASS
EEG mu peak at rest
8–13 Hz
PASS
EEG gait artifact at stride rate, step rate and harmonics
>1.5× off-harmonic baseline
PASS
Artifact-to-neural ratio grows with speed
below 0.35 at rest, above 1 running hard
PASS
Cadence and motion artifact respond faster than heart rate
time to 63% of change compared
PASS
Heart rate stays elevated after dropping from hard run to jog
more than 10 bpm above steady state
PASS
Final walking cadence 100–115 steps/min
within 98–118
PASS
Full sequence returns to REST; no NaN or jumps
REST at about 56 s
PASS
Display limiter rarely engaged (no flat tops)
all channels under 2% of samples near limit
PASS
No overstriding: foot lands near hip, shank near vertical, knee flexed
foot ≈2 px ahead of hip, shank −3° to −6°
PASS
Stance foot does not slide on the ground
difference below 0.05 px/s
PASS
Drawn heel strikes per minute equal displayed cadence
108 vs 109, 174 vs 176
PASS
References and what each one supports
Each entry was opened and read for this page, except where noted. Support is limited to the claim stated.
Peer-reviewed
Pulse arrival time. Heimark S, et al. Blood pressure altering method affects correlation with pulse arrival time. Blood Press Monit 2022;27(2):139-146. doi:10.1097/MBP.0000000000000577. Defines PAT as R wave to a PPG fiducial point, reports about 181 ± 23 ms at rest (PPG foot), PAT falling during isometric and dynamic exercise, and notes PAT includes the pre-ejection period. Supports the delay concept and its direction with exercise, not the exact model values.
Hamstring timing. Mao L, Ren D, Huang S, Wu X, Ruan M. Fascicle behavior and muscle activity of the biceps femoris long head during running at increasing speeds. J Sports Sci Med 2024;23(3):603-610. doi:10.52082/jssm.2024.603. Reports highest activity in late swing and early stance, rising from about 83% to 116% of MVC between 4 and 6 m/s. Supports the main burst timing only. It does not support the smaller bursts.
Fast heart-rate response at exercise onset. Fontolliet T, et al. Vagal blockade suppresses the phase I heart rate response but not the phase I cardiac output response at exercise onset in humans. Eur J Appl Physiol 2021;121(11):3173-3187. doi:10.1007/s00421-021-04769-3. Phase I was roughly 50% (supine) to 70% (upright) of the heart-rate change and was largely abolished by atropine, which points to vagal withdrawal. The 50/50 fast and slow split in the model is a simplification inspired by this, in a 0-80 W cycling protocol with nine young men.
Gait artifact in EEG, walking. Snyder KL, Kline JE, Huang HJ, Ferris DP. Independent component analysis of gait-related movement artifact recorded using EEG electrodes during treadmill walking. Front Hum Neurosci 2015;9:639. doi:10.3389/fnhum.2015.00639. Reports spectral peaks near the step frequency and related frequencies, more prominent at faster speeds, and warns that ICA can produce apparently neural components from artifact. The paper does not use the word "harmonics" in the text I read.
Gait artifact in EEG, jogging. Ledwidge PS, et al. A comparison of approaches for motion artifact removal from wireless mobile EEG during overground running. Sensors 2025;25(15):4810. doi:10.3390/s25154810 (PMC12349273). Reports EEG power at the gait frequency (2-3 Hz) and its first two harmonics during jogging, greatest at the gait frequency and reduced but not always eliminated by cleaning. Only part of the page text was available to me, so I cannot confirm every detail of its methods.
Not cited
Cadence values. Walking at 100-115 steps/min and running at 145-176 steps/min are design values chosen for the animation. I have not verified a peer-reviewed source for a typical running cadence, so none is claimed, and no single cadence is presented as universal. Running cadence varies with speed, height, training and the individual.
Time constants, respiratory sinus arrhythmia depth, EEG amplitudes, and the late-stance and early-swing EMG bursts have no source here. They are modelling choices.
Limitations
Time is compressed. Heart-rate and exercise-intensity time constants are a few seconds so changes are visible in a short interaction. Real adaptation takes longer. These constants are not taken from a cited study.
No comparison with real recordings. No simulated trace was compared with measured ECG, EMG, PPG or EEG data. Agreement with the literature is qualitative.
Fixed ECG shape. Morphology does not change with posture, lead or exercise ST changes. The P-to-R interval check is only reliable at moderate rates, because at very short R-R the windows of neighbouring waves overlap.
EMG is one muscle. A single hamstring channel. Amplitude saturates with speed, whereas the cited running study shows activation still rising from 4 to 6 m/s. The extra stance and early-swing bursts are simplifications.
PPG delay is a design value. It is measured to the maximum upslope, which comes later than the pulse foot used in the cited resting PAT figure.
EEG rhythms are illustrative. Mu and beta amplitudes and their modulation during gait are simplified. No source localization or artifact-removal method (for example ICA) is shown.
Runner has no flight phase and is a side-view sprite, so joint angles are plausible, not measured.
Everything is synthetic. The page says so on the signal readout.
How the checks are run
The checks run the same simulation code as the page headlessly, at 250 Hz of simulated time, and compute each result from the generated samples. Results above come from that run on the current published version.