Instrumentation & Measurement Magazine 23-4 - 22

Research Advances of Indoor
Navigation for Blind People:
A Brief Review of
Technological Instrumentation
Darius Plikynas, Aru¯nas Žvironas, Marius Gudauskis, Andrius Budrionis,
Povilas Daniušis, and Ieva Sliesoraityte˙

lind persons need electronic traveling aid (ETA)
solutions for better orientation and navigation in
unfamiliar indoor environments, with embedded
features for detection and recognition of both obstacles and
desired destinations such as rooms, staircases, and elevators.
Because the use of GPS for locational references is impractical indoors, the development of such navigation systems is
challenging and requires a systematic review and evaluation
of different technological approaches. Using the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method, we evaluated and compared current
research papers that deal with the prototyping of assistive
devices (visual sensory perception substitution with audio
and haptic signals) for blind and visually impaired persons.
We conducted an instructional assessment of selected indoor
navigation prototypes using three main criteria: navigation
technologies, sensors, and computer vision approaches. For
the latter category, we conducted a separate systematic review,
as papers in this research area primarily specialize in software
computer vision solutions rather than hardware. The paper
provides useful insights for researchers regarding technological instrumentation for the development of ETA solutions for
blind and visually impaired (VI) persons in the field of indoor
orientation and navigation.

Introduction to ETA Instrumentation
One of the main tasks of ETA solutions for blind and VI people is location detection and navigation [1], [2]. This function
has been more or less successfully implemented for outdoor
environments with the aid of GPS technology [3]. However,
for indoor environments, the use of GPS or equivalent satellite
systems is limited due to the lack of a direct line of sight and
weakening of GPS signals when crossing walls. In this case,
special techniques or technologies must be used [4].
Before starting to develop a new solution or improve existing technology, however, it is necessary to investigate and

compare existing solutions and technologies. This study is
dedicated to that purpose. We performed a systematic review of indoor ETA instrumentation as applied to currently
developed research prototypes. We hope it will provide
value-added knowledge regarding instrumentation and measurement for researchers and developers in this field.
We found that the number of new publications on the research into, and development of, ETA solutions for blind and
VI people has been growing over the past five years. Most of
the publications provide information about different sensors
and assistive devices. A significant portion of these solutions
involves detecting obstacles and solving orientation and navigation issues.
Although many advanced solutions for orientation and
navigation are currently available, only a few systematic review articles were discovered [5], [6], as very few authors
provide systematized, structured, and tested information on
the technology, functionality, and end-user ratings of their solutions. For instance, we can find a systematized summary of
wearable devices, grouped by the technologies used in [2]. The
reviewed systems and devices are classified into two main
groups: sensor-based and video camera-based solutions. A
comprehensive analysis of visual assistive technologies is provided in [7]. Here, vision substitution solutions are divided
into three subcategories: ETA solutions, electronic orientation
aids, and position locator devices. The authors also provide a
quantitative evaluation of selected features. An evaluation of
various wireless technologies and algorithms for indoor positioning solutions is provided in publication [8].
In sum, this paper identifies current research trends in the
development of indoor navigation systems for blind and VI people. It also cross-validates whether new indoor ETA technologies
meet the expectations and requirements of blind and VI people, pointing out what is missing and what should be improved.
This article is organized as follows: First, the method of systematic review employed in this paper is described. The next

This project received funding from the European Regional Development Fund
(project No 01.2.2-LMT-K-718-01-0060) under a grant agreement with the Research Council of Lithuania (LMTLT).
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June 2020

Instrumentation & Measurement Magazine 23-4

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