IEEE - Aerospace and Electronic Systems - November 2019 - 26

Feature Article:

DOI. No. 10.1109/MAES.2019.2933971

RF Sensing Technologies for Assisted Daily Living in
Healthcare: A Comprehensive Review
Syed Aziz Shah, Francesco Fioranelli, University of Glasgow, U.K.

INTRODUCTION
The proportion of people aged over 65 years is increasing
worldwide with various estimations projecting the percentage of over 65 in next 50 years in the European Union [1].
The challenge of aging population is pushing toward novel
healthcare provision that evolves from the traditional hospital-based system, where the patients are treated or monitored
for severe health conditions in a controlled environment, to
a more person-centric approach where the patients are
observed in their homes remotely via modern technology.
This home-centric healthcare model can improve the quality
of life of different patients suffering from chronic diseases
including Parkinson's, dementia, epilepsy, narcolepsy, and
multiple sclerosis, and enables them to live longer and better
by minimizing the disruption to their usual routine and lifestyle. Moreover, providing the traditional levels of hospitalbased healthcare for the increasing number of older people
would be unfeasible for families and public authorities,
hence there is need to find cost-effective and reliable solutions based on emerging technologies.
A challenge to overcome is the provision of reliable
and continuous monitoring of individuals at risk, while at
the same time allowing them to live independently in their
homes. In first instance, the monitoring system needs to
detect critical events such as falls or other potentially dangerous behavior, and alert family, care-givers, or first responders for prompt help. The risk of dangerous behavior
increases with many health conditions such as Freezing of
Gait (FOG) Parkinson's disease, wandering behavior in
dementia, sleep attack in narcolepsy disease, and seizure
in epilepsy disease, affecting older individuals. Studies

Authors' current addresses: Syed Aziz Shah, School of
Computing and Mathematics, Manchester Metropolitan University, U.K. (e-mail: S.Shah@mmu.ac.uk).
Francesco Fioranelli, School of Engineering, University
of Glasgow, Glasgow G12 8QQ, U.K.
Manuscript received February 19, 2019, revised April 8,
2019, and ready for publication August 6, 2019.
Review handled by R. Wang
0885-8985/19/$26.00 ß 2019 IEEE
26

estimate that 67% of the dementia patients may exhibit
wandering behavior as the disease progresses because of
the memory loss and weariness [2]. There is a danger that
the patient might leave home or fall and injure him/herself. Similarly, a bedridden or frail older patient might
develop bedsores due to lack of repositioning and limited
mobility on bed. Sleep apnea is a condition where a person
suddenly stops breathing for some time while asleep. FOG
is a brief, episodic absence or marked reduction of forward
progression of the feet despite the intention to walk, and is
one of the most debilitating motor symptoms in
Parkinson's patients, as it may lead to falls [3].
Narcolepsy is a neurological disorder that affects the control of sleep and wakefulness [4]. Narcolepsy patients
might fall asleep while performing daily routine activities.
Epilepsy is also one of the neurological conditions where
people experience seizures and involuntary body movements, while performing activities of daily living (ADL).
The incidence of these diseases increases with aging,
together with a general reduction in mobility due to cardiovascular and musculoskeletal problems, with each individual affected by multiple conditions (multimorbidity).
Many technologies in the literature have been presented for patients monitoring. Camera-based sensors are
light dependent, require that the subject should remain in
line of sight while being observed, and may raise privacy
concerns in private rooms (e.g., bathrooms and bedrooms). Ambient sensors such as acoustic receivers, pressure pads, or passive infrared can be disrupted by ambient
interference (noise for acoustic or heat sources for thermal
infrared) and are expensive to retrofit in home environments. Wearable devices that consist of accelerometer,
gyroscope, and magnetic sensors can also be used for
monitoring daily routine activities and health related
parameters, but these must be worn or carried by the monitored subject, with potential issues of acceptance, discomfort, and compliance. Nevertheless, both sensor-based and
vision-based methods come at high costs thanks expensive
devices, deployment, and maintenance overhead. Some of
the advantages and limitations are shown in Table 1 [5].
The use of Radio-Frequency (RF) sensing has been
considered in recent years in the context of assisted living,

IEEE A&E SYSTEMS MAGAZINE

NOVEMBER 2019

IEEE - Aerospace and Electronic Systems - November 2019

Table of Contents for the Digital Edition of IEEE - Aerospace and Electronic Systems - November 2019