jasc- paper Essay

Design of Antenna for Real Time Breath Detection

Jemi Anugraha #1, Maria Sharon Sanjana *2

KCG College of Technology, Department o f Electronics and Communication, Karapakkam

[email protected]

[email protected]

Ms. B Thyla assistant professor (Sel. Grade)

ABSTRACT —This paper presents 2 wearable models based on ISM antenna for real tim e breath detection.

It demonstrates a novel design of a compact fiber antenna which has been developed for medical

applications. The proposed antenna covers a frequency range from 2.4 GHz – 2.

5 GHz. A new generation

of wearable antenna is presented, and its potential use as a contactless and non -invasive sensor for human

breath detection is demonstrated. The antenna is made from multimaterial ?ber designed for short -range

wireless network applications at 2.4 GHz frequency. It this project various antenna shapes are analyzed

in using HFSS software/environment based on the return loss, gain & radiation pattern. The spiral

shaped fiber antenna is chosen as the optimum design on promising comfort or restricting movement of

the user due to their high ?exibility, and ef?ciently shield the antenna from the environmental

perturbation. Breathing rate (BR) is a vital sig n used to monitor the progres sion of illness and an

abnormal BR is an important indicator of serious illnes s.

Variation in BR can be used to predict potentially serious clinical events such as heart attack.

Keywords — ISM (Industrial Scientific Medical) band, HFSS (High Frequency Struc ture Simulator) , wearable

antenna, BR (Breathing rate), Multimaterial fibre.

1. INTRODUCTION

With t he exponential development of wireless communication technologies, researchers are now focusing on the study of

Wireless Body Area Network (WBAN), which allow the communication between wearable devices (on -body communications),

between body -worn devices a nd surrounding devices (o? body communications), and ?nally between implanted devices and

devices mounted on human body surface (in -body communications) .

Breathing (or respiration) is an important physiological task in living organisms. Breathing rate (B R) is a vital sign used to

monitor the progression of illness and an abnormal BR is an important indicator of serious illness. Variation in BR can be us ed

to predict potentially serious clinical events such as heart attack. For example, using changes in BR measurements, patients

could have been identi?ed as high risk up to 24 h before the event with 95.5% con?dence. BR monitoring devices are separated

into two categories: contact and non -contact sensors. In contact BR monitoring sensor, a direct physical contact with the body is

needed. Howe ver, in non -contact monitoring sensor, the BR is measured without making contact with the subject’s body. The

most popular contact -based approach to derive the BR is from the ECG signal.

Several antenna designs have been proposed for medical applications i n the industrial, scienti?c and medical (ISM) and Ultra

High Frequency (UHF) bands fabricated a modi?ed inverted -F antenna inkjet printer directly on the fabric using silver

nanoparticle ink with a frequency radiating at 2.45 GHz. With the rapid progress o n the fabrication of conductive textile, silver

yarn was used to create a spiral antenna for a system that senses heart rate, fall detection and measures ambient temperature .

II. PROPOSED METHOD

A spiral ?ber antenna was integrated into a ?tted T -shirt at the mid -chest position, allowing the chest expansion to slightly

stretch the antenna. The operating frequency shift was continuously measured using a VNA connected to the antenna through an

SMA.

2

Connector by mean of a coaxial cable, with this con?guration, performed a series of measurements to detect breathing of a

volunteer asked to take four breaths, followed by one minute of relaxed, shallow breathing, and four more deep breaths. A

frequency sh ift of 120 MHz was detected for deep breathing, while relaxing, shallow breathing led to smaller 4 –15 MHz

frequency shifts. These measurements validate the proposed respiration sensor based on multimaterial ?ber in spiral shape

arrangement integrated into a standard T -shirt for breath detection. Although these measurements seem to be very promising,

the user’s comfort which is an important factor as discussed in the introduction needs to be addressed. Received signal stren gth

based breathing monitoring is e merging as an alternative non -contact technology. A wireless systems operating at a 2.4 -GHz

frequency to estimate the respiration rate has been presented recently, and showed limitation in term of detection accuracy a nd

heavy mathematical treatments.

III. Design using HFSS

Two fibre antenna have been designed using HFSS and their parameters have been studied.

Table 1: Model specifications

Model Dimension Operating

frequency

Gain Return l oss

Half wave dipole

antenna

Length=61mm 2.45GHz 3.34dBi -32.5dB

Spiral Length=10cm 2.45GHz 3.34dBi -27.5dB

Model 1

Half wave Dipole shape antenna

Materials involved – Polyamide, polystyrene, silver

Length=61mm

Feed at the centre

Gain – Ranges from -25dB to 5dB

Return loss at 2.45GHz = 0.00001dB

Fig 1: Dipole shaped antenna

3

Fig 2: A closer look at the dipole antenna

A. GAIN

Gain of the antenna is to direct the input radiation in a particular direction producing the output of the radiated

antenna. The gain of the antenna is shown in figure 3.

Fig 3: Gain of the dipole antenna

Generally the gain value should be positive, i.e.>0dB. Here, the gain value is taken with respect to the theta value.

Outer radius of

181µm

Inner radius of 100

µm

4

B. RADIATION PATTERN

Radiation pattern of the antenna is defined as a graphical representation of the radiation properties of the antenna

as a function of space coordinates which is shown in figure 4.

Fig 4: Radiation Patte rn

C. VSWR

The parameter VSWR is a measure that numerically describes how well the antenna is impedance matched to the

radio or transmission line it is connected to. VSWR stands for Vo ltage Standing Wave Ratio.

Fig 5: The VSWR of the dipole antenna

5

Model 2 (Chosen model)

Half turn Archimedean spiral shape antenna

Materials involved – Polyamide, polystyrene, silver

Length=10cm

Gain – Ranges from 5 dB to -12.5 dB

Return loss at 2.45GHz = 0. 000 dB

Fig 6: S Shaped antenna

This fibre antenna is designed with the inner silver coating having the thickness of 150±30 nm. The measured electrical dc

resistivity of 3.8 ± 1 ?/cm for the inner silver conductor along with the geometry of the structure of the antenna provides a good

electrical matching to the standard 50 ? impedance of the RF components, while the external polyim ide coating provides long –

term protection against the heat/humidity in the environment. Using the conductive multimaterial ?ber, the simplest designed

antenna for 2.4 GHz operating frequency: a half -turn Archimedean spiral shape. Half -turn Archimedean spiral is a special case

of the dipole antenna with ?/2 at 2.4 GHz equals to 10 cm fabricated using two 50 mm long ?ber. As it is known from the

antenna theory, operating frequency of the dipole and loop antennas can be adjusted for p articular applications simply by

varying their length.

6

A. GAIN

Fig 7: Gain of the S Shaped antenna in terms of Theta

B. RADIATION PATTERN

Fig 8: Radiation pattern of S Shaped antenna

7

C. VSWR

Fig 9: VSW R of S Shaped antenna

IV. CONCLUSION

A new generation of wearable antennas for healthcare monitoring was designed by integrating polymer -glass -metal

?ber composites into a well de?ned geometry. The mechanical properties of the ?ber enable an easy integr ation of the antenna

into textile using the classical weaving methods, thus leading to a development of new wireless communication platform. The

RF emissive performance of the textile -integrated ?ber loop, dipole and spiral antennas were characterized in t erms of return

loss, radiation pattern and gain, and found to be comparable to the commercial wireless router antennas, and suitable for sho rt

range wireless networks in the ISM band at 2.4 GHz.

The goal of this work was to demonstrate the capability of th e newly developed sensor to detect in real time the breathing

patterns of a human and communicate the data via a Bluetooth protocol at 2.4 GHz to a base station. For medical applications,

such as in situ diagnose of respiratory illnesses and monitor people suffering from asthma, or chronic obstructive pulmonary

disease, it is important to validate our system. This could be done by a head -to-head comparison with gold standard equipment

such as a spirometer or a pneumotograph, which is the subject of our futu re work.

ACKNOWLEDGEMENT

I sincerely express my gratitude to all the authors who have published papers on medical application of antennas, I wold also

like to extend my thanks to all the professors for motivating us to carry out this project.

8

REFER ENCES

[1] Jo?ao Vicente Faria: “Flexible Antennas Design and Test for Human Body Applications Scenarios” 2015

[2] M. Koohestani, “Human body proximity e?ects on ultra -wideband antennas,” Ph.D. dissertation, ? Ecole Polytechnique

F?ed?erale de Lausanne an d Instituto Superior T?ecnico, Sep 2014.

[3] Mourad Roudjane, Mazen Khalil, Amine Miled and Youn?s Messaddeq “New Generation Wearable Antenna Based on

Multimaterial Fibre for Wireless Communication and Real -Time Breath Detection” 11 October 2018

[4] George Shaker, Student Member, IEEE, Sa?eddin Safavi -Naeini, Member, IEEE, Nagula Sangary, Member, IEEE, and

Manos M. Tentzeris, Fellow, IEEE “Inkjet Printing of Ultra wideband (UWB) Antennas on Paper -Based Substrates” Date of

publication January 17, 2011.

[5] A min Rida, Li Yang, Rushi Vyas, and Manos M. Tentzeris “Conductive Inkjet -Printed Antennas on Flexible Low -Cost

Paper -Based Substrates for RFID and WSN Applications” IEEE Antennas and Propagation Magazine , Vol. 51, No.3, June

2009.

[6] Jaspreet Singh, Jyoti “Design of Wearable Textile Antenna for Wireless and Medical Applications” IJISET – International

Journal of Innovative Science, Engineering & Technology , Vol. 5 Issue 10, October 2018.

[7] Md. Masudur Rahman, d. Mozaffor Hossain, Kallol Krishna Karmakar “? -shape micro strip antenna design for WiMAX,

Wi -Fi and biomedical application at 2.45 GHz” 2013 3rd IEEE International Advance Computing Conference (IACC ).

[8] Majumder, S.; Mondal, T.; Jamal Deen, M. Wearable Sensors for Remote Health Monitoring. Sensor s 2016 .