“…In terms of technology, 'assistive technology' can be regarded as a general term, so the keyword appeared more frequently and stands as a root of the map in Figure 7. Subsequently, specific technologies emerged for services with explicit demands, such as ultrasonic sensors [32], infrared sensors [33], computer vision [34], ultrawideband (UWB) [35], and GPS [36] to collect environmental information; image processing [37], convolutional neural network (CNN) [38], and deep learning [14] to achieve advanced intelligence; stereo audio [39], audio-tactile maps [40], and haptic feedbacks [41] to bridge humans and machines. From the perspective of requirement, 'accessibility', 'mobility', and 'wearable' are among the most popular keywords.…”