Instrumentation & Measurement Magazine 26-4 - 21

(in upload) and 300 Mbps (in download). However, these relatively
high data rates and long-range coverages are generally
counterbalanced by higher power consumption.
In order to meet the power consumption constraints typical
of sensor networks, a derivation of the LTE standard
designed for IoT applications requiring data rates around 250
kbps downlink and 20 kbps up-link has been proposed, namely
Narrow-Band IoT (NB-IoT). With similar aims, LoRa has been
proposed, although it works on unlicensed bands and provides
the physical layer for developing LoRaWAN®, which is supported
by the LoRa Alliance. The LoRaWAN® specification is a
Low Power, Wide Area (LPWA) networking protocol designed
to wirelessly connect battery-operated 'things' to the internet in
regional, national or global networks, and targets key Internet
of Things (IoT) requirements such as bi-directional communication,
end-to-end security, mobility and localization services,
with data rate typically below of 100 kbps.
Examples of Distributed Measurement
Systems and Measurement Applications
Wearable and Networked IMU to Monitor and
Capture Movement Disorders in Patients with
Neurodegenerative Diseases
The digitization of the healthcare system is one of the European
Commission's objectives for the next five years [20].
COVID-19 highlighted the fragility of national healthcare systems
and reinforced the need for converging toward digitized
healthcare systems. In this context, the study of telemedicine
is rapidly becoming a topic of great interest in the scientific
community as well, and it aims to combine and use innovative
technologies to make healthcare easier and more accessible
to everyone. Remote health monitoring represents one of
the possible solutions to be applied in the field of telemedicine
[21]: the patient can be observed by the doctor directly at
home while carrying out his/her normal daily activities. This
may lead to a reduction in stress caused by traveling to specialized
clinics and decrease long waiting lists; furthermore,
real-time monitoring allows doctors to respond quickly to abnormal
conditions and prescribe customized treatments. To
meet these requirements, it becomes important to find networked,
low-power, low-cost, non-invasive, and accurate
measurement systems that allow data storage and real-time
communication from patient to doctor. These features are
well represented by wearable sensors, which are widely used
as devices to detect movement disorders in patients affected
by neurodegenerative diseases. In particular, the use of characterized
Inertial Measurement Unit systems (IMU) and the
implementation of motion analysis algorithms can help the
doctor suggest a more accurate diagnosis based on objective
measurements [22]. In the case of Parkinsonian patients, such a
measurement system can correctly identify typical movement
June 2023
Fig. 1. System architecture for data exchange communication.
disorders (i.e., tremors, bradykinesia, dyskinesia) caused by
the disease.
There are different wearable devices used to detect movement
disorders [23]; in particular, in [24] the researchers
focused their attention on IMU, namely MetaMotionR (MMR),
which is a nine-axis device characterized by an accelerometer,
gyroscope, and magnetometer. The small size of the sensor
means that it can be worn by the subject in a non-intrusive way.
The communication technology used to acquire data from
the device is based on the Bluetooth Low Energy 4.0 Smart®
module, which allows direct connection via a proprietary application
called MetaBase.
The architecture and communication system are described
and illustrated in Fig. 1. The sensor node is represented by the
MMR, which is able to acquire information such as acceleration,
angular velocity, and magnetic field. Communication
with the device is enabled via the MetaBase application, which
allows the user to set the measurement parameters of interest
and enables streaming data acquisition or data storage on the
onboard flash memory (8 MB). Once the data have been acquired,
they are downloaded and sent via Bluetooth to the PC.
Because the MMR is a commercial device used and tested in
other motion capture applications, it was not necessary to develop
a specific body network as it was preferred to exploit
already established hardware and communication technologies.
Most energy is spent in the data processing phase by
developing specific motion analysis algorithms.
The Bluetooth LE communication protocol used in the
described application is robust and reliable. The low power
consumption during the data acquisition phase allows a longer
battery life and thus a usage between 8 to 24 hours in
streaming mode, and between 2 to 48 hours in recording mode.
The architecture adopted is simple and easy to use both by the
doctor in the clinical environment and by the patient directly
at home.
An IoT Distributed Platform for Radon
Concentration Measurement
The radioactive decay of uranium found in underground soil
produces radon, a radioactive gas that has no smell, color,
IEEE Instrumentation & Measurement Magazine
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