Abstract — Cerebral Oximetry NIRS
of bNIRS and EEG signals, and demonstrate its use on multi-channel bNIRS data recorded with concurrent EEG on healthy adults during a visual stimulation task. We introduce the use of the Finite Impulse Response functions within the General Linear Model for bNIRS and show its feasibility to statistically localize the haemodynamic and metabolic activity in the occipital cortex. Moreover, our results suggest that the fusion of haemodynamic and metabolic measures unveils additional information on brain functioning over haemodynamic imaging alone. The cross-correlation-based analysis of interrelationships between electrical (EEG) and haemodynamic/metabolic (bNIRS) activity revealed that the bNIRS metabolic signal offers a unique marker of brain activity, being more closely coupled to the neuronal EEG response.
Sensor Interfacing & Analog Front-End Conditioning
Over the past few decades, neuroimaging technologies have allowed us to advance our knowledge of the mechanisms underlying human brain function, both in health and disease. Functional neuroimaging methodologies are widely used in the fields of cognitive neuroscience and neuropsychology in order to investigate the relationship between a specific task or mental function and the corresponding patterns and/or locations of brain activity. Different functional neuroimaging techniques are based on different principles, and can be broadly categorized as: electrophysiological (e.g., electroencephalography (EEG) and magnetoencephalography (MEG)), haemodynamic (e.g., functional magnetic resonance spectroscopy (fMRI) and functional near-infrared spectroscopy (fNIRS)), and metabolic (e.g. fluorodeoxyglucose positron emission tomography (FDG-PET) and broadband near infrared spectroscopy (bNIRS)). Each of these capture different and complimentary aspects of brain function, distinguished by the complex sequence of neurophysiology that underlies the generation of their signals.
Bio-Signal Waveform Analysis & Simulation Findings
Furthermore, each modality has strengths and limitations that largely depend on the spatiotemporal characteristics of the signal. Electrophysiological recordings provide direct measures of neuronal activity with high temporal resolution but poor spatial resolution, while haemodynamic and metabolic imaging methods are able to indirectly assess brain activity by capturing the physiological changes linked to neurovascular and neurometabolic coupling, with better spatial specificity but lower temporal resolution. It has therefore become increasing popular to fuse data from multiple imaging modalities to yield a more detailed understanding of brain dynamics.
Scope & Clinical Applications
- Real-time multi-parameter vital signs telemetry (ECG, Heart Rate, SpO2, Temperature, Respiration)
- Low-noise Analog Front-End (AFE) conditioning with active Driven Right Leg (DRL) 50 Hz cancellation
- Digital signal processing in MATLAB: Pan-Tompkins QRS detection, FIR/IIR notch, and Continuous Wavelet Transforms
- Finite element tissue bio-electromagnetics and orthopedic mechanical simulations in COMSOL & ANSYS
- Complete Arduino firmware .INO sketches, circuit schematics, and university dissertation reports
Bio-Potential Sensors
ECG, EEG, EMG & PPG optical probes
Low-Noise AFE
INA128 / AD8232 instrumentation amps
Arduino Firmware
Real-time ADC interrupt sampling & BLE
MATLAB Bio-DSP
Pan-Tompkins QRS & wavelet transforms
COMSOL Multiphysics
Tissue electro-thermal & SAR simulation
IEC 60601-1 Safety
Galvanic optical & magnetic isolation
Biomedical Sensors, Electronics & Simulation Suites
Engineered using clinical-grade bio-transducers, low-noise analog amplifiers, and multi-physics simulation platforms.
| Subsystem / Software | Diagnostic & Engineering Role | Instrumentation Tier |
|---|---|---|
| Arduino / ESP32 MCU | High-speed SPI/I2C sensor polling, 500 Hz timer interrupt ADC sampling, BLE telemetry streaming | Embedded Hardware |
| MATLAB R2024b | Pan-Tompkins QRS detection, 50 Hz Butterworth notch filtering, wavelet decomposition, SpO2 ratio | Signal Analytics |
| COMSOL Multiphysics | Electromagnetic tissue absorption (SAR), bio-heat thermal transfer, acoustic transducer wave propagation | Tissue Physics |
| ANSYS Mechanical | Orthopedic bone-implant contact mechanics, prosthetic socket stress distribution, dental load FEA | Biomechanics FEA |
| AD8232 / ADS1298 AFE | Medical-grade 3-lead ECG front-end with built-in instrumentation amp, DRL feedback, and high CMRR | Clinical AFE IC |
Biomedical Acquisition & Multi-Physics Simulation Workflow
Comprehensive signal flow from human bio-potential electrodes and optical sensor probes to embedded Arduino firmware, MATLAB DSP, and COMSOL tissue modeling.
(ECG/EEG/PPG/Temp)
(INA128 / DRL Loop)
500Hz ADC Sampling
& QRS Detection
Tissue FEA Models
& EHR Dashboard
Verified Medical Waveforms, Diagnostic Images & Sensor Circuits
Advantages of the Cerebral Oximetry NIRS Project
Why this biomedical engineering project delivers superior academic grades and provides high technical evaluation standing.
Clinical Diagnostic Precision
Combines high-CMRR analog front-ends with precision digital filtering to extract microvolt bio-potentials with high SNR (> 35 dB).
Rigorous IEC 60601-1 Patient Safety
Incorporates dual galvanic isolation barriers (optical/magnetic) ensuring patient auxiliary leakage currents remain strictly under 10 μA.
Multi-Sensor Vital Signs Fusion
Simultaneously captures ECG, PPG, SpO2, Core Temperature, and Respiration for comprehensive physiological health monitoring.
Real-Time Arduino Embedded Firmware
Features optimized C++ interrupt-driven ADC sampling routines ready for immediate deployment on Arduino, ESP32, and STM32.
Validated Pan-Tompkins QRS Algorithm
Executes derivative, squaring, moving-window integration, and dual-threshold peak detection with > 99% R-peak accuracy.
COMSOL & ANSYS Multi-Physics Coupling
Models complex anatomical tissue structures, bio-electromagnetic Specific Absorption Rates (SAR), and prosthetic stress fields.
Driven Right Leg (DRL) Noise Suppression
Actively senses and neutralizes 50/60 Hz powerline hum and common-mode displacement currents without loading patient electrodes.
DICOM Medical Imaging Pipeline
Processes clinical MRI, CT, and Ultrasound scans using MATLAB contrast enhancement and morphological lesion boundary segmentation.
Direct Telehealth & Hospital IoT Readiness
Streams validated vital signs to mobile dashboards and electronic health records over encrypted BLE and MQTT protocols.
Complete Turnkey Project Package
Delivered with full Arduino .INO sketches, circuit schematics, MATLAB .m algorithms, university-format report, and viva defense slides.
Sample Arduino Firmware, ECG Waves & Sensor Telemetry
Representative excerpts illustrating the embedded sensor acquisition loop, live physiological waveform traces, and clinical parameter schedules.
[*] Initializing Analog Front-End (AFE) Signal Acquisition... [✓] Driven Right Leg (DRL) Active Feedback: 50 Hz Hum Attenuated by 42 dB ──────────────────────────────────────────────────────────────────────── [10:14:02.102] TRACE ECG Lead-II: ---__/\_/\_/\___ (Baseline: 0.02 mV | Normal ST Segment) [10:14:02.115] QRS R-Peak Registered (Fiducial Trigger: 1.24 mV | R-R Interval: 832 ms) [10:14:02.128] VITALS Heart Rate: 72.1 BPM | SpO2: 98.5% | PR Interval: 156 ms [10:14:02.140] TRACE ECG Lead-II: ---__/\_/\_/\___ (Baseline Stable | SNR = 36.8 dB) ──────────────────────────────────────────────────────────────────────── [✓] Diagnostic Evaluation: Sinus Rhythm Verified. Zero Ectopic Ventricular Beats.
[*] Synchronizing vital signs telemetry stream across bio-sensor channels...
| Physiological Parameter | Primary Transducer | Measured Amplitude | Sampling Bandwidth | Clinical Status |
|---|---|---|---|---|
| Cardiac Electrocardiogram (ECG) | Ag/AgCl + AD8232 AFE | 1.24 mV (R-Peak) | 0.05 Hz - 150 Hz | NORMAL SINUS |
| Pulse Oximetry (SpO₂) | MAX30102 Dual Red/IR | 98.5% Saturation | 100 Hz Optical | OPTIMAL |
| Heart Rate (HR) | R-R Peak Derivative | 72.1 BPM | 30 - 220 BPM range | EUKINETIC |
| Core Body Temperature | NTC Medical Thermistor | 36.8 °C | 0.1 Hz Thermal | AFEBRILE |
[✓] Diagnostic Evaluation: Patient physiological parameters within verified clinical tolerance band.
Frequently Asked Questions
Project Deliverables & Support
Everything needed from project inception to final viva defense — delivered with expert biomedical support.
.INO Sketches
Schematics
Algorithms
Report
Slides
Models
Datasets
Q&A
Support
Extension