## 4 Intelligent Wearable Solutions for VRU Safety: Trends, Challenges, and Opportunities
### Wearable Assistive Devices for Visually Impaired Users
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Reference** & **Year** & **Interface Technology** & **Experimental Validation Method** \\ \hline [PERSON] et al. [62] & 2013 & Vibrotactile belt with multiple motors for information transfer and obstacle avoidance & Testing with five subjects for vibration perception evaluation; a total of 49 subjects in game simulation for reaction time and collision avoidance \\ \hline [PERSON] et al. [70] & 2014 & Smartphone-based navigation assistant using computer vision with chest-mounted harness & Comprehensive survey and comparative analysis of 12 wearable systems for visually impaired navigation \\ \hline [PERSON] et al. [57] & 2016 & Electronic spectacle with four ultrasonic sensors and dual-mode audio and vibrotactile feedback & Performance evaluation with 20 participants to measure response time to vibration warnings; blind spot evaluation of sensor coverage \\ \hline [PERSON] et al. [81] & 2017 & Monocular camera-based system with deformable grid algorithm for obstacle detection and avoidance & Objective performance testing using RGB-D camera to establish ground truth; compared with five conventional methods across three scenarios \\ \hline [PERSON] et al. [82] & 2017 & Wearable system with bone-conducting earphones and camera using adaptive extraction and consistency analysis algorithm for crosswalk detection & Field testing with five blindfolded subjects; compared algorithm performance with bipolarity-based methods \\ \hline [PERSON] et al. [64] & 2018 & Wearable collision warning device with shoulder-mounted camera and vibrotactile wristbands & A total of 29 blindfolded and 8 blind subjects testing obstacle navigation, warning accuracy, and navigational decision-making \\ \hline [PERSON] et al. [83] & 2018 & RGB-D camera wearable system for intersection navigation with three integrated detection modules & Performance testing against previous algorithms; field trials at six intersections with blindfolded subject \\ \hline [PERSON] et al. [71] & 2018 & Wearable RGB camera-based navigation system with temporal alignment technique and pose estimation for path following & Testing across six indoor and six outdoor paths using chest-mounted camera and headphones \\ \hline [PERSON] et al. [63] & 2019 & Low-cost open source ultrasound-sensing based wrist-worn navigational device with vibrotactile feedback & Testing with five blindfolded subjects across nine practical navigation scenarios, including indoor/outdoor obstacle detection and avoidance \\ \hline \hline \end{tabular}
\end{table} 
Table 8: _Cont._ \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Reference** & **Year** & **Interface Technology** & **Experimental Validation Method** \\ \hline [PERSON] et al. [73] & 2019 & IoT-enabled wearable navigation system with Raspberry Pi, camera, ultrasonic sensors, GPS, and GSM modules & Lab testing of neural network object identification and ultrasonic distance ranging; demonstrated GSM emergency notification capabilities \\ \hline [PERSON] et al. [74] & 2019 & Novel framework for outdoor mobility assistance using multisensor data fusion, advanced computer vision, and auditory display & Proposed framework with experimental design for data collection from visually impaired users; planned evaluations using cross-validation and statistical measures \\ \hline [PERSON] et al. [58] & 2020 & ODG R7 smart glasses with custom algorithms for crosswalk guidance using computer vision and verbal cues & Testing with three visually impaired subjects in both indoor (simulated) and outdoor crosswalk scenarios \\ \hline [PERSON] et al. [75] & 2020 & Nvidia Jetson TX2 portable GPU and ZED camera, designed for integration with bone-conduction headsets for audio feedback & Testing with custom dataset of 3693 urban intersection images \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Summary of orientation interfaces for visually impaired pedestrians (Part 2: 2019–2025).