Glossary

Searchable terminology from accessibility, web standards, and related fields.

4 results found in physiological sensing.

Autonomic Nervous System (ANS)
The division of the nervous system that regulates involuntary physiological processes including heart rate, blood pressure, respiration, digestion, and stress responses. The ANS has two main branches:…
Functional Near-Infrared Imaging (fNIR, fNIRS, Functional Near-Infrared Spectroscopy)
A neuroimaging technique that measures brain activity by detecting changes in oxygenated blood volume using near-infrared light transmitted through the skull. In accessibility contexts, fNIR enables b…
Heart Rate Variability (HRV)
The variation in time intervals between consecutive heartbeats, reflecting the balance between sympathetic (stress response) and parasympathetic (rest and recovery) branches of the autonomic nervous s…
Photoplethysmography (PPG)
A non-invasive optical technique used to detect blood volume changes in peripheral circulation, commonly implemented in wearable devices like smartwatches and fitness trackers. PPG sensors use light (…