Glossary

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Accelerometer

A sensor that measures acceleration forces, including the constant force of gravity, along one or more axes. Accelerometers in smartphones and wearable devices detect device orientation, movement, and gestures. In accessibility applications, accelerometer data enables…

Activity Monitoring(also: Activity Recognition, Activity Tracking)

The use of sensors, algorithms, and computational models to automatically detect and track a person's actions and behaviours within an environment. In assistive technology contexts, activity monitoring enables smart home systems and cognitive orthoses to understand what a person…

Bio-Electrical Signal(also: Biosignal, Bioelectrical Signal, Physiological Signal)

A bio-electrical signal is an electrical potential generated by biological processes in the human body, including muscle contractions (EMG), brain activity (EEG), eye movements (EOG), heart rhythms (ECG), and skin conductance (GSR). In assistive technology, bio-electrical…

Capacitive Touch(also: Capacitive Sensing, Capacitive Touch Sensing)

A touch detection technology that works by measuring changes in electrical capacitance when a conductive object, such as a human finger, comes near or contacts an electrode surface. The finger and electrode form a capacitor whose capacitance changes upon contact, and this change…

Corneal Reflection(also: Pupil-Center Corneal Reflection, PCCR)

An eye tracking technique that works by shining a near-infrared light at the eye and measuring the relationship between the reflection off the cornea (the bright spot called the glint) and the center of the pupil. As the eye rotates to look at different screen positions, the…

Depth Sensing(also: Depth Perception (computer vision), 3D Sensing)

The ability of a sensor or system to measure the distance from itself to objects in the scene, producing a depth map or point cloud rather than a flat image. Common approaches include stereo vision (triangulating between two cameras), structured light (projecting a known…

Digital Compass(also: Electronic Compass, Magnetometer)

An electronic sensor that detects the Earth's magnetic field to determine the direction a person or device is facing, providing heading information in degrees or cardinal directions. In assistive technology for blind and visually impaired users, digital compasses are integrated…

EMG Switch(also: Electromyography Switch, Muscle Signal Switch)

An assistive technology switch that detects electrical signals produced by muscle contractions (electromyography) to generate a switch activation. EMG switches can detect even very small muscle movements, such as a slight facial twitch or jaw clench, making them suitable for…

Electroencephalography(also: EEG)

A non-invasive method of recording electrical activity of the brain using electrodes placed on the scalp. In assistive technology, EEG is the primary sensing technology behind brain-computer interfaces (BCIs), which allow people with severe motor impairments such as paralysis or…

Electromagnetic Tracking(also: Magnetic Tracking, 6-DOF Tracking)

Electromagnetic tracking is a position and orientation sensing technology that uses electromagnetic fields to determine the location and rotation of a sensor in three-dimensional space. Systems like the Polhemus tracker generate a low-frequency magnetic field from a stationary…

Electrooculogram(also: EOG, Electrooculography)

The electrooculogram (EOG) is a technique for measuring the electrical potential difference between the front and back of the eye using surface electrodes placed around the eyes. This corneal-retinal potential (CRP) varies linearly with eye rotation along both horizontal and…

Gyroscope(also: Gyro Sensor)

A sensor that measures rotational velocity around one or more axes, detecting how quickly a device is being turned or twisted. Combined with accelerometers in an inertial measurement unit, gyroscopes provide detailed motion tracking that enables gesture recognition, orientation…

Human Activity Recognition(also: HAR, Activity Recognition)

A field of machine learning and ubiquitous computing that uses sensor data — typically from accelerometers, gyroscopes, and other sensors in smartphones, smartwatches, or other wearable devices — to automatically identify and classify physical activities performed by a person.…

Inertial Measurement Unit(also: IMU)

An electronic sensor module that combines accelerometers and gyroscopes (and sometimes magnetometers) to measure motion, orientation, and gravitational forces. IMUs are embedded in smartphones, smartwatches, and other wearable devices, where they can detect gestures, track…

Inertial Sensing(also: IMU sensing, Inertial measurement)

The use of accelerometers, gyroscopes, and magnetometers — often built into smartphones and wearable devices — to measure motion, orientation, and direction of movement. In accessibility applications, inertial sensing enables dead reckoning for indoor navigation where GPS is…

Infrared Emitting Diode(also: IRED, IR LED, Infrared LED)

A light-emitting diode that produces infrared radiation, used in assistive technology for motion tracking and position sensing. IREDs are commonly used in head-tracking systems, eye-tracking devices, and other assistive input methods where a camera detects the infrared light…

Location Awareness(also: Location-Aware Computing, Location Sensing)

The ability of a computing system to determine and respond to the physical location of a user or device, typically using GPS, Wi-Fi positioning, cellular triangulation, or other sensing technologies. In assistive technology, location awareness enables context-sensitive support…

Multimodal Sensing(also: Multi-Modal Sensing)

The simultaneous capture of data through multiple sensor channels - for example, combining physiological signals (heart rate, galvanic skin response, skin temperature) with behavioural signals (motion, audio, button input, pressure) - to produce a richer picture of a user's…

Occupancy Grid Map(also: 2D occupancy grid, Grid map)

A representation of an environment as a grid of cells, where each cell is labelled as walkable (free space), non-walkable (obstacle or wall), or unknown. Occupancy grid maps are a standard data structure in robotics and are increasingly used in blind-navigation systems built on…

Passive Infrared Sensor(also: PIR Sensor, PIR, Motion Sensor)

A passive infrared sensor detects movement by measuring changes in ambient infrared radiation in its field of view — typically body heat from a person moving across the detection zone. PIR sensors are inexpensive, low-power, and require no active emission, which makes them a…

Physiological Sensing(also: Biosensing)

Measuring bodily signals - such as heart rate, galvanic skin response, skin temperature, respiration, or muscle activity - to infer aspects of a user's physical or affective state. Physiological sensing is widely used in accessibility, affective computing, and digital health to…

Posture Detection(also: Posture Monitoring, Posture Recognition)

The use of sensors or computer vision to identify and monitor a person's body posture in real time. In assistive technology, posture detection systems can use accelerometers, gyroscopes, or cameras to determine whether a user is sitting, standing, slouching, or hunching, and…

RGB-Depth Camera(also: RGB-D camera, Depth camera)

A camera that captures both a conventional colour image (RGB) and a per-pixel depth map, usually via structured light, time-of-flight, or stereo sensing. RGB-D cameras are widely used in assistive navigation systems for people who are blind because they enable real-time…

RGBD Camera(also: RGB-D Camera, Depth Camera, Stereo Camera)

A camera that captures both a colour (RGB) image and a per-pixel depth (D) measurement of the scene, yielding a 3D representation of the environment. Depth can be produced by stereo vision, structured light, or time-of-flight sensing. In accessibility research RGBD cameras…

Signal Drift(also: Baseline Drift, DC Drift)

Signal drift is the gradual, unintended change in the baseline level of a measured signal over time, caused by factors unrelated to the intended measurement. In bio-electrical sensing for assistive technology, drift is a major challenge — for example, in electrooculography…

Surface Electromyography(also: sEMG, Surface EMG)

A non-invasive technique for measuring the electrical activity produced by skeletal muscles, using electrodes placed on the skin over the muscle. Surface EMG is used in biomechanics, prosthetic control, rehabilitation, and — increasingly — as an input modality for accessible…

Touch Sensor(also: Touch-Sensitive Sensor, Tactile Sensor)

An electronic component that detects physical contact or proximity of a finger or object on a surface. Touch sensors are used in accessible devices to enable direct tactile interaction, allowing blind users to trigger audio feedback by touching specific locations on a physical…

Ultra-Wideband(also: UWB, Ultra wideband)

A short-range radio-frequency technology that uses very wide frequency bands (typically above 500 MHz) and very short pulses to enable centimetre-accurate distance and angle-of-arrival measurements between paired devices. UWB is increasingly used in accessibility for indoor…

Visual Evoked Potential(also: VEP, Visually Evoked Response, VERP)

A visual evoked potential (VEP) is an electrical signal generated by the brain's visual cortex in response to a visual stimulus, typically a flash of light or a pattern change. VEPs are measured using electrodes placed over the occipital lobe and extracted from background EEG…

Wearable Sensor(also: Body-Worn Sensor, Wearable Device)

A small electronic device worn on the body that continuously collects data about the wearer's movements, physiological state, or environment. In accessibility and rehabilitation contexts, wearable sensors such as accelerometers, gyroscopes, and inertial measurement units can…

Wearable Sensors(also: Body-Worn Sensors, Wearable Sensor Technology)

Electronic devices worn on the body that collect data about movement, physiological signals, or environmental conditions. In accessibility contexts, wearable sensors include accelerometers, gyroscopes, and inertial measurement units (IMUs) embedded in clothing, shoes, watches,…

31 results.