Abstract— This daily news proposes a miniaturized Ultra-Wide Band (UWB) ingestible supplement antenna to get wireless supplement endoscopy (WCE). The antenna is a compact planar placed microstrip patch antenna which has a modified part ground airplane. Rogers TMM 13i is used as the substrate material of the antenna. The estimated environment with the whole individual gastrointestinal (GI) tract with surrounding damaged tissues is designed with CST Microwave Studio and the performance in the antenna can be investigated by simply placing it in the centre in the environment. The proposed antenna size is 85 mm3 (10 mm × 10 logistik × zero. 9 mm), resonant consistency is about 5. 5 Gigahertz with a -10 dB band width of about installment payments on your 9 GHz ranging from a few. 1 GHz to 6 Gigahertz, and the light pattern is usually omnidirectional with circular polarization in the neurological model. It really is observed the fact that maximum rays efficiency is usually -28. 39 dB. The SAR benefit in GI tract is usually determined intended for biocompatibility examination.
Index Terms—Wireless supplement endoscopy, Pills antenna, UWB antenna, Ingestible antenna, Stomach tract.
Advantages
Cellular capsule endoscopy (WCE) can be described as noninvasive method for visualizing the complete gastrointestinal (GI) tract, where traditional endoscopy cannot reach the inside of small intestine [1]. Moreover, the standard endoscopy possessing a long and flexible tube furnished with a video camera passes through human neck to anal area which causes pain and discomfort. Doctors advise a supplement endoscopy instead of a traditional one particular, to find the reason behind GI bleeding, to identify the inflammatory bowel illnesses, cancer, celiac disease and so forth [1].
A Wireless capsule is actually a vitamin-size tablet usually below 11 logistik × 31 mm (diameter × length) in size [2], consists of several microelectronic circuits, sensors, a CMOS camera, LEDs, battery and a transmission device antenna which in turn communicates with the external products to display the photographs or effects of the GI tract although passing through it. Thus an antenna is actually a vital a part of WCE.
Ingestible tablet antennas have to be small to support inside the supplement. In addition , it should be omni-directional and circularly polarized so that the info can be transmitted independent of the course and orientation of the tablet and to include higher bandwidth for real time video transmission of GI Tract [2]. Most importantly, it needs being operated inside a sensitive environment i. electronic. human body. So , it is a tough task to design such kind of antenna.
Many analysts have designed different types of sending antennas pertaining to WCE just like spiral, conical helix, microstrip loop etc . [3]. For instance, Lim et al. [4] recommended two types of dual music group planar antenna having scale 30 millimeter × twenty-five mm and 23 logistik × 24 mm correspondingly for WCE inside a basic human box model which will operates in 500MHz with about 250MHz bandwidth. Within study, Guo and Chu [5] developed a planar inverted-F antenna of size 18 mm × 10 millimeter for wi-fi ingestible tablet inside a one-layer cube muscle phantom that operates at ISM (2. 4-2. twenty four GHz) strap. In addition , a conformal 434 MHz in-body capsule antenna of twelve mm long and six mm in diameter that remains combined below –10 dB in wide range of human body tissues is usually constructed simply by Nikolayev ainsi que al. [6]. Additionally, Li ainsi que al. [7] proposed a conformal circularly polarized (CP) capsule antenna of five mm in radius and 15 millimeter in length inside a one-layer homogeneous muscle phantom model that provides 10-dB impedance bandwidth of 31. 58%. Furthermore, a conformal trapezoid strip thrilled broadband hemispherical dielectric resonator antenna of volume 134 mm3 within a tissue simulating fluid plantom that works at extra wide-band (UWB) low group 3. 1-4. 8 Gigahertz has been proposed [8]. Currently, companies such as Olympus, Intromedic, and Philips produce WCE supplement named Endocapsule, MicroCam, and Intellicap [2, 9]. However , the bandwidth with the above mentioned antennas are not enough for real time transmission. Although UWB antenna of volume level 81 mm3 [10] and 528. 864 mm3 [11] have been recommended for high data rate (bandwidth 1 . 8 Gigahertz and installment payments on your 2 GHz respectively) WCE inside the allocated UWB frequency band of 3. 1 GHz to 10. 6 GHz, almost always there is a range of miniaturization and band width enhancement in the antenna.
In this newspaper, a UWB compact planar slotted patch antenna in the frequency array of 3. you GHz to six GHz is recommended for WCE and its overall performance is analysed throughout the GI Tract unit. The issues of this style to get over were size miniaturization, improving the bandwidth with an optimized resonant frequency, having omni-directional the radiation pattern with circular polarization and protecting patient security. The paper is organized as follows. Section II describes the antenna design and human GI tract version. Section III analyses the performance in the antenna inside the GI tract. Finally, Section IV shows the concluding remarks and future recommendations.
Style and Unit
Different aspects of the antenna design and human GI tract unit are mentioned below:
Antenna Design
The proposed antenna consists of a doing patch, a ground aircraft, and a substrate. With this design, the substrate is sandwiched involving the patch and ground.
The volume of designed microstrip patch antenna is 80 mm3 (10 mm × 10 logistik × zero. 9 mm) in size, which is only three or more. 16% with the capsule quantity.
The structure of the proposed antenna is demonstrated in Fig. 1 plus the sizes of antenna’s parts are stated in Table I. From this work, Rogers TMM 13i is chosen as a substrate because it includes a high family member permittivity (εr = 12. 85) and loss tangent (tanδ sama dengan 0. 0019) which allows by lowering the successful wavelength for this miniaturized antenna. The patch and earth are made of copper mineral.
The partial earth plane can be used to improve rays property. To boost the band width, the top sides of the surface are taken out. Notches will be introduced in the top centre of the earth to improve the impedance coordinating as well as to improve the bandwidth [12].
The conducting patch is actually a circular area of 2. five mm radius calculated using the formula [13] which is provided below:
(1)
exactly where is the radius of the spot, is the velocity of light inside the medium, is definitely the dielectric frequent of the substrate, and is the resonant rate of recurrence.
An advantage (+) shape slot can be introduced in the centre of the patch and a divide ring slot machine game is encircled outside the slot machine to enhance the bandwidth along with optimize the resonant frequency. Those slots decrease the Q-factor of the spot antenna while increase patch inductance. The bandwidth is definitely inversely proportional to the Q-factor. So the bandwidth is enhanced. At the same time, these types of slots associated with operating regularity range of the antenna reduce for a given size because of the resonance regularity being inversely proportional for the inductance in the patch. Two square slot machine games were also presented on the edge of the plot to obtain a sole feed circularly polarized antenna. The axial ratio was optimized making use of the parameters Ws and Ls [14].
The antenna is definitely fed through a waveguide dock. The spherical patch is definitely fed by a feed range with a complementing section of thickness 1 . 6 mm.
TABLE My spouse and i
Geometrical Sizes of the Proposed Antenna
Variable Value(mm)
Substrate Length, D = 12, Width, Watts = 15, Thickness = 0. 4
Patch C1 = 2 . 5, C2 = 1 . 5, C3 = 1 . 3, S1 = 1, S2 sama dengan 0. your five, Ls = Ws = 0. eight, Thickness sama dengan 0. twenty-five
Feed Range M1 sama dengan 1 . almost eight, M2 = 1 . almost 8, M3 = 3. 2, Thickness sama dengan 0. twenty-five
Ground A = several, B sama dengan 1, C = installment payments on your 8283, Width = 0. 25
To represent the capsule shell, the antenna is covered having a biocompatible material Teflon (εr = installment payments on your 1 and tanδ = 0. 0002) which maintains patient safety.
Human GI Tract Style
The ingestible antenna travels along the human GI tract which will comprises of esophagus, stomach, small intestine, huge intestine, rectum, and rectum. Thus, the models of a persons esophagus, abdomen, small is going to and large intestinal tract have been designed for simulating the approximate environment.
The esophagus have been modelled with a circular tube of 70 mm size and 12 mm radius, as demonstrated in Fig. 2 (a). Additionally , Fig. 2 (b) shows a 20 millimeter radius of spherical tummy model. Additionally, a rounded cylinder shape of small intestine including 85 mm duration and twelve mm radius is proven in Fig. 2 (c). A box model of huge intestine also has been designed with the dimensions of 40 millimeter x 70 mm times 40 millimeter, as displayed in Fig. 2 (d).
In addition , the surrounding cells (muscle, fat, skin) layers are placed in a sequential manner around many of these four types. The small dimension values with the four models have been selected for the sake of simplicity and quicker computational period. The get across section of the complete GI tract is demonstrated in Fig. 3. Desk II provides the properties of the tissues utilized in the ruse at your five GHz [15], [16]. The antenna is positioned at the center of the 4 GI system models, because shown in Fig. four and corresponding simulated answers are carried out to another section.
The ingestible antenna provides a minimum reflection coefficient magnitude (|S11|) of -20. 02 and a -10dB band width of about installment payments on your 9 Gigahertz ranging from several. 1 GHz to 6 GHz throughout the GI tract. Considering that the fractional bandwidth is higher than 50% through the GI tract, so it is an UWB antenna.
Radiation Pattern
The 2D far field radiation pattern from the antenna in E-plane and H-plane in the four cells models at the resonant regularity is displayed in Fig 6. Through the radiation pattern, it is evident that the antenna shows omni-directional radiation pattern throughout the GI tract to get both E-plane and H-plane. So the antenna will be able to transfer information all around independent of the direction and orientation of the pills which is important for ingestible antenna.
The 3D the radiation pattern of the antenna within the four tissue models of GI tract is definitely presented in Fig. several. The directivity of the antenna is found to be some. 76 dBi, 4. 59 dBi, some dBi, and 4. 46 dBi inside esophagus, belly, small intestinal tract, and large intestine respectively. The radiation efficiency and total effectiveness of the antenna in free space is usually -0. 3396dB and -0. 7398dB correspondingly, however , because of surrounding lossy tissues, the radiation efficiency and total performance is reduced to -28. 39 deutsche bahn and -28. 46 dB respectively within the GI tract shown in Table III.
The proposed antenna in this paper is more miniaturized and recieve more bandwidth than the antennas of [4], [5], [8], [10], and [11]. Alternatively, the antenna provides a better optimized size and band width than the antennas of [6] and [7].
Results
The paper shown the design, ruse and analysis of a small UWB ingestible capsule antenna for wireless capsule endoscopy. The antenna and the 4 regions of the field of operation in the antenna i. e. gastrointestinal tract happen to be modelled in CST Microwave studio. The simulation effects show which the antenna works at about some. 5 GHz with a -10dB bandwidth of about 2 . 9 GHz which range from 3. 1 GHz to six GHz, gives omni-directional the radiation pattern with circular polarization.
On the other hand, this antenna can be used for WCE, generally there needs a great experimental analysis to confirm the simulated results. Foreseeable future work will be included to manufacture a prototype with the antenna and also to design UWB conformal antennas for WCE.
