Design and Implementation of a Safe Medical Box to Maintain Insulin Pens in Good Conditions

Full text

Design and Implementation of a Safe Medical Box to Maintain
Insulin Pens in Good Conditions
Roy ABI ZEID DAOU1,2, Elie BOUTROS1, Tony YOUSSEF1, Ali HAYEK3, Josef BOERCSOEK3 and Jose Javier
SERRANO OLMEDO4
1 Lebanese German Unviersity, Faculty of Public Health, Biomedical Technologies Department, Sahel Alma, Lebanon – email:
r.abizeiddaou@lgu.edu.lb
2 MART Learning, Education and Research Center, Chananiir, Lebanon – email: roydaou@mart-ler.org
3 Department of Computer Architecture and System Programming, University of Kassel Kassel, Germany -email:{ali.hayek ;
j.boercsoek} @ uni-kassel
4 Lab of Bioinstrumentation and Nanomedicine, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Spain -
email: josejavier.serrano@upm.es
Abstract— Diabetes is becoming one of the most relevant medical
problems in today’s world. The insulin pen is a largely used
medication to limit the effects of this disease. However, this tool must
be reserved in good conditions in order to maintain its efficiency. A
very important parameter is the ambient temperature where the
insulin pen is placed. The below system provides a solution to
monitor and to control the temperature of the insulin pen. It consists
of creating a portable medical box with two chambers where new and
in-use pens are placed. Based on the temperature of these chambers,
a control unit acts to heat up or to cool down the chamber
temperature, therefore, the insulin pen reaches again the desirable
temperature range. Concerning the applied tools, temperature and
object detector sensors have been used to detect the presence of the
insulin pen whereas a Peltier device was used to heat up/cool down
the chamber temperature. Polystyrene was also implemented in the
design of the chamber to create more isolation to the system. In order
to increase electrical safety and system accuracy, some components’
redundancy has been applied, mainly at the level of the processing
unit and the temperature sensor. The system was tested for several
hours while phone application notifications were registered when the
chamber temperature was outside the acceptable range. Regarding
the control process, tests have shown that the system works well and
is very accurate.
Keywords— Insulin Pen; Isolation; Electrical Safety; Diabetes
Illness; Temperature Monitoring and Control; Phone Application
I. INTRODUCTION
Diabetes is one of the most frequent medical
problems that about ninth of the population face
nowadays. A projection for 2040 shows that this
percentage may rise to reach tenth of the population as
proposed by the International Diabetes Federation [1]. In
the last few years, diabetes was considered one of the
most dangerous diseases according to the world health
organization as 8.5% of adults aged 18 years and older
had diabetes in 2014. It was also the direct cause of 1.6
million deaths in 2016 and high blood glucose was the
cause of another 2.2 million deaths in 2012 [2].
As for the medication, a big percentage of the patients
use insulin pens in order to control the sugar blood level.
This pen must be maintained in a well reserved place
along with a pre-defined temperature level. Failure to
comply with this specification leads, on several
occasions, to the medication distortion; if consumed, this
may risk the life of the diabetic patient [3].
Regarding the temperature environment range where
the insulin pen must be stored, Kongmalai et al. showed
that in use insulin pens must be preserved in a
temperature between 24°C and 30°C [4] while non-used
pens must be kept in an area where the temperature
varies between 2°C and 8°C as shown by Romito [5]; A
domestic fridge may vary its temperature in a broader
rage, even between zero and 15ºC since.
Concerning engineering tools developed for diabetes
patients, Sezdi et al. proposed, in 2016, a new insulin pen
that can control the time and the dosage of insulin to be
delivered to the patient. This system was developed using
electronic components and it was mainly used to help old
persons and the ones with vision or mental problems to
take their medication in the correct way [6].
In the same year, another system was also proposed
by Ugar et al. in order to help blind patients taking the
right dose of their insulin medication. The system
consists of developing an electro-sensing system capable
of setting the exact dose [7].
Therefore, the main objective of this work is to
propose a system that handles insulin pens and acts in a
way to reserve them in the required temperature ranges
without changing the usual pen that the patients use.
Thus, the novelty of this work is to develop a low
cost, reliable and portable system that can hold more than
one pen, and most importantly, that allows to insert new
and already in use pens. As the system deals with
patients’ health, the electrical safety is also considered in

the design in order to limit errors and to increase
accuracy.
This paper is divided as follow: section II proposes
the block diagram of the whole system. Section III
presents the hardware tools used to design and implement
the system. In section IV, the phone applications and the
alarm system are proposed. At the end, section V shows
the results of this system, a conclusion and will propose
some future works that may enrich this work.
II. BLOCK DIAGRAM
Figure 1 shows the block diagram of the system.
There are two containers to insert the in-use and the new
insulin pens. For each container, there is a controller that
can heat or cool the chamber. Both containers are
separated using well isolating material. In addition, the
whole system is isolated too in order to decrease the
energy consumed for heating and cooling it.
A processing unit is responsible to monitor and
control the temperature of these containers as well as to
transmit data, via a Bluetooth module, to the phone
application for monitoring.
The portable system is also equipped with two types
of alarms: an audible alarm and a visual one that are
turned on whenever the battery is low or the containers’
temperatures are not in the required ranges for several
minutes.
As for the communication protocol between the
system and the mobile, a Bluetooth connection was used
as the insulin box must be with the patient when going
outside. However, switching to other communication
protocols as WiFi or GSM is still an option that does not
require of much modification.
Concerning the duplications, the main system failures
were detected at the level of the power supply, the
processing unit, the accuracy of the temperature sensor
and the alarms. Thus, we have opted to use a good
quality power supply and to duplicate the other
components to limit errors and to increase system
accuracy.
Regarding the choice of sensors, actuators and
processing units, they will be presented in detail in the
next section.
Insulen Pen Container
Processing
Unit
(duplicated)
Temperature
Sensor (2 sensors
per container)
Object
Detector
Sensor
Control signal
Heater/
Cooler Device
Power Supply
unit
Isolation
Material
Phone
Application
Alarm System
(audible and
visual)
Figure 1. Block diagram of the proposed system
III. HARDWARE TOOLS
This section will present all hardware-related
components applied for the design and the
implementation of the proposed system. The choice of
the different modules was made referring to their cost,
accuracy, power consumption, and size.
A. Sensors
To ensure the main objectives of the proposed system,
two measurements are needed: temperature and object
detection.
Concerning the temperature monitoring, DHT11
sensor was used to measure the temperature of the two
containers where the insulin pens are placed. This sensor
has a thermistor based on 4 pins to power up the system
and to deliver data. Its temperature measurement range is
between 0°C and 50°C, and its accuracy is ±1.0°C. It
needs low energy to power up, and its size is compatible
with the system. This sensor delivers an 8-bit analog
output ranging between 0V and 5V with a conversion
ratio of 0.1V/°C [8].
As for the detection of the insulin pens in the
container, the infrared sensor was used. The module
detects an object within a distance range between 2cm
and 30cm. This sensor generates a digital output where a
low voltage corresponds to the presence of the insulin
pen. This module requires an input voltage of 5V and a
current of less than 50mA. It operates between -10°C and
50°C [9]. Thus, an IR sensor was placed in each
container to check the presence of the insulin pens.
Whenever they are present, the algorithm to regulate the
temperature within each container is initiated. In case of
their absence, no heating or cooling to the container is
applied.
B. Actuators
The actuators were used to control the temperature of
the two containers. The desired average temperature of

the in-use insulin pen’s chamber is 27°C, whereas, for the
new pens, the temperature chamber is 6°C. In order to
reach this objective, a heating/cooling system, based on
the thermoelectric cooler also known as peltier cooler,
was applied. This module is a semiconductor-based
electronic component.
As for its functioning, when applying a low DC
voltage, the heat will be moved from one side to the other
side through the semiconductor, leading the module face
to be cooled while the opposite one will be heated
simultaneously. This phenomenon will be reversed by
reversing the polarity of applied power.
The thermoelectric cooler consists of two or more
semiconductor material elements that are connected
electrically in series and thermally in parallel. These
thermoelectric elements and their electrical interconnects
typically are mounted between two ceramic substrates.
The substrates serve to hold the overall structure together
mechanically and to insulate the individual elements
electrically from one another and from external mounting
surfaces. After integrating the various component parts
into a module, thermoelectric modules size typically
40mm x 40mm x 3.75mm [10] [11].
As for its features, it can have a temperature
difference of 70°C between both sides whereas its
working environment temperature ranges between -55°C
and 83°C. Concerning its power consumption, it needs a
supply voltage of 12V and can handle a maximum
current of 5.8A.
C.
Alarms system
The alarms of the system were implemented at two
levels: internal alarms in the insulin medical box and
external alarms via the phone applications (this latter will
be described in the next section).
Concerning the internal alarms, three leds were used:
the first one blinking when the battery level becomes low
whereas the two others are green whenever the
temperatures in the containers are wihtin the required
values, although they switch to red light when the actual
temperature is outside the targeted range. A beeper is
added to generate an audible alarm if one of the situations
described above occurs.
Added to that, a beeper is added to generate an
audible alarm if one of the occurences prescibed above
occurs.
D.
Communication protocol
The main objective of this module is to send the
temperature values of the two chambers from the
processing unit to the phone for monitoring. Bluetooth
communication was used and the HC-06 module was
connected to the main processing unit. It will be paired
with the Bluetooth module of the mobile phone in order
to send and receive data.
E.
Power supply
Concerning the sensors and the control unit, they
need 5V with a very low current consumption. The total
current is lower than few tenth of milliamps. However,
the main energy consumption device is the Peltier
thermo electrical heat conditioner as it may need 5.8A
and a supply voltage not lower than 12V.
Thus, a 12V/50.800 mAh portable car jump starter
pack battery was used to run the device. It weighs about
350g and can run the system continuously for about 60
minutes, which is more than needed thanks to the
implemented isolation system [12].
F.
Isolation Technique
Polystyrene is a waterproof thermoplastic foam
which is an excellent temperature insulation material
[13]. It is FDA approved and can be used in contact with
food [14]. Added to that, it is of low cost and low weight
material. It can be found easily in the market as boards
of 3cm or 5cm sick within different dimensions. In the
proposed system, a 3cm sickness material was used to
reduce the volume.
G.
Processing Unit
In order to control and monitor the above sensors, a
control unit is a must. Thus, two Arduino Uno
microcontrollers were used as they are low cost
components, easy to program, and open source, contains
the needed analog and digital pins and can handle
wireless connection module [15].
Figure 2 shows the connection between the modules
and one of the Arduino microcontrollers pins. As for the
second one, it has the same connectivity but it is not
connected to Bluetooth. However, both controllers
communicate together to compare their processing
outputs before sharing the results to the phone application
via this Bluetooth module.
Figure 2. Connections between the sensors and main Arduino
microcontroller

Figure 3 shows the flowchart of the algorithm
running on the main microcontroller. Once initialized, the
system tests first the battery level as well as the presence
of insulin pens in each container. If the battery level is
below 20% (value also confirmed from the second
microcontroller), an alarm is generated within the system
and is also sent to the phone application. In addition,
whenever an insulin pen is present in the appropriate
container, if the temperature range of the chambers is
outside the acceptable ranges, other alarms are also
generated (as discussed in the above paragraphs) and the
control process is initialized to heat up/cool the chamber
cell.
So, before generating the alarms, the main
microcontroller reads the values computed by the
secondary microcontroller. If the same outputs are
obtained, data is sent to the phone application and alarms
are turned on if required.
Figure 3. Flowchart of the main microcontroller code
In more details, figure 4 shows the flowchart applied
for the control of the in-use insulin pens container. We
have decided to specify the temperature between 25°C
and 29°C which is wihtin the range already specified in
the first section of this paper (24~30°C).
Added to that, one can notice that the peltier is turned
on, for both cooler and heater modes, for few seconds.
This time is enough to get the required temperature. If
the system can’t reach the required range within two
minutes, an alarm is sent to the phone application and is
displayed on the box itself. This can explain that the
used batteries can last for more than one day.
Figure 4. Flowchart of the temperature control of the in-use insulin pen
container
IV. PHONE APPLICATION
In this section, the mobile application will be
presented. This application allows the patient to monitor
and, when necessary, to be alerted of the temperature of
the chambers where the insulin pens are placed.
The MIT app inventor was used to develop this
application. It displays, via Bluetooth connectivity
between the insulin pen microcontroller and the mobile
phone, the temperature of each chamber, the presence of
the insulin pens in the chambers and the battery voltage.
If the temperature of any chamber is out of range for
at least two minutes, the application sends a voice
message to the user and a text will be displayed on the
screen every two minutes until the temperature value is
back to the acceptable range. In addition, if the device's
voltage is lower than 20% of its total energy capacity, a
voice and a text message are sent.
Figure 5 shows the display of the phone application
along with all its functionalities as already presented.
Figure 5. Main view of the mobile application

V. RESULTS, CONCLUSION AND FUTURE WORKS
This system was implemented, assembled and tested.
Each module was tested alone in first place, and
afterwards the whole system was tested to measure its
accuracy and the battery lifetime. Figure 6 shows some
photos of the implemented systems.
Concerning the results, the whole system was tested
for about 36 hours in different environments where the
ambient temperature was fluctuating. Three pens were
inserted in the box (one in-use insulin pen and two new
pens as was displayed previously in the phone
application). The containers temperature got outside the
required ranges 17 times for the in-use insulin pens and
36 times for the new insulin pens. The peltier was turned
on for an average 35 seconds each time. After the trial,
the application showed that there is still about 31% of the
battery life.
Figure 6. Some photos of the insulin medical box
As a conclusion, the proposed system is able to
monitor and control the temperature, and to detect the
presence of the insulin pens in two different containers.
The phone application was designed to display to the user
the current parameters values and the battery level
percentage. Added to that, notifying the user in case of
low battery level or if the temperature is out of range is
an additional feature found integrated within the system
itself and within the phone application.
The testing of this system has shown good results
especially concerning the temperature monitoring and
controlling, the battery voltage level, the detection of the
pens in the chambers, the communication between
application and microcontroller and the peltier control.
Concerning the cost of this system, it was about 130$
compared to 20$, the cost of a single insulin pen. One
can get a lower system cost by using smaller batteries, as
the cost of the battery constitutes about 40% of the total
system cost.
As for the future works, the proposed system can be
improved in many ways. Here below, some of the ideas
are listed
• With a higher budget, these basic sensors can be
replaced with higher quality sensors that will allow
more accurate data recording;
• Developing a server dedicated to the application thus
all the monitoring results will be saved so the user
could check them when needed;
• Using a better and slimmer isolation material to get
more efficiency and reduce the devices size;
• Using a photovoltaic boards to recharge the battery to
enhance the usage time.
REFERENCES
[1]
International Diabetes Federation, "IDF DIABETES ATLAS -
8TH EDITION," IDF, 1 1 2017. [Online]. Available:
https://diabetesatlas.org/across-the-globe.html. [Accessed 23 4
2019].
[2]
w. h. organization, diabetes, WHO, 2018.
[3]
HealthLine, "Insulin Regular, Injectable Solution," HealthLine,
[Online]. Available: https://www.healthline.com/health/regular-
insulin-injectable-solution. [Accessed 06 May 2019].
[4]
T. Kongmalai, L. Preechasuk, S. Junnu, S. Manocheewa, C.
Srisawat and A. Sriwijitkamol, "The Effect of Temperature on
the Stability of In-Use Insulin Pens," American Diabetes
Association.diabetes, p. 67, 2018.
[5]
K. Romito, "Learning About Insulin Pens," MyHealth - Alberta -
Canda, 7 December 2017.
[6]
M. Sezdi and A. Bilen, "Bilensulin: Time and dose controlled
electronic insulin pen design," in Medical Technologies
National Congress (TIPTEKNO), Antalya, Turkey, 2016.
[7]
T. Ugar, O. Kogak and A. Akpek, "New concept design of an
insulin pen for visually impaired or blind diabetius mellitus
patients," in Medical Technologies National Congress
(TIPTEKNO), Antalya, Turkey, 2016.
[8]
Mouser Electronics, "DHT 11 Humidity & Temperature
Sensor," Mouser Electronics, Munich, Germany, 2011.
[9]
TkkrLab, "Arduino KY-032 Obstacle avoidance sensor
module," TkkrLab, 08 January 2018. [Online]. Available:
https://tkkrlab.nl/wiki/Arduino_KY-
032_Obstacle_avoidance_sensor_module. [Accessed 06 May
2019].
[10]
thermal.ferrotec, Thermoelectric Technical Reference, USA:
Ferrotec USA, 2019.
[11]
R. Atta, "Thermoelectric Cooling," in Bringing
Thermoelectricity into Reality, England, IntechOpen, 2018, pp.
247 - 267.
[12]
Amazon, "50800Mah Car Starter Battery Start Kit 12V,"
Amazon, [Online]. Available: https://www.amazon.com/Car-
Power-Bankusb3-0-Emergency-Flashlight/dp/B07K58YJ2X.
[Accessed 06 May 2019].
[13]
t. masterbuilder, "Thermal Insulation Material and Processes,"
The masterbuilder , 16 october 2018.
[14]
"polysteren," ChemicalSafetyFacts, 2019.
[15]
H.-
P. Halvorsen, "Introduction on Arduino.," University College
of Southeast Norway, Norway.
[16]
N. Boonma, A. Sangthong, S. Mitatha and C. Vongchumyen,
"Image recorder server with IP camera and pocket PC,"
Procedia Engineering, vol. 8, pp. 182-185, 2011.