Biosignale

Biosignale are signals produced by living organisms that carry information about physiological states and processes. They can be electrical, chemical, or mechanical and are typically measured with sensors placed on or in the body.

Electrical biosignals include ECG, EEG, EMG, and EOG, which reflect heart activity, brain activity, muscle activity, and eye movements, respectively. Non-electrical biosignals include photoplethysmography (PPG), respiration curves, blood pressure waveforms, and chemical measurements such as glucose or lactate concentrations. Biosignals can be recorded non-invasively, invasively, or implantably, depending on the application.

Data are acquired with suitable instrumentation, amplified, filtered, and digitized. Processing steps may include artifact removal, segmentation, feature extraction in time, frequency, or time–frequency domains, and interpretation via diagnostic criteria or machine learning models.

Applications span clinical monitoring (intensive care, cardiology, neurology), diagnostics, rehabilitation, sleep research, brain–computer interfaces, sports science, and consumer wearables that track health and performance.

Challenges include variable signal quality, motion and physiological artifacts, inter-subject variability, standardization of measurement protocols, data privacy, and regulatory considerations for medical use.

Research in biosignale aims to integrate multiple signals for richer assessments, improve real-time analytics, and enable new interfaces between humans and devices.