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دانلود رایگان مقاله انگلیسی + خرید ترجمه فارسی
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| عنوان فارسی مقاله: | تجزیه و تحلیل و شبیه سازی مدل تکثیر برای ارتباطات بی سیم حسگر های زیستی |
| عنوان انگلیسی مقاله: | Analysis and Simulation of Propagation Model for Wireless Communication of Bio-Sensors |
| مشخصات مقاله انگلیسی (PDF) | |
| سال انتشار | 2010 |
| تعداد صفحات مقاله انگلیسی | 4 صفحه با فرمت pdf |
| رشته های مرتبط | کامپیوتر، مهندسی ارتباطات وفناوری اطلاعات ICT، شبکه های کامپیوتری و مدیریت فناوری اطلاعات |
| مجله | کنفرانس بین المللی شبکه های بی سیم ارتباطات و محاسبات موبایل(International Conference on Wireless Communications Networking and Mobile Computing) |
| دانشگاه | گروه علوم کامپیوتر دانشگاه اقرا، کراچی، پاکستان |
| کلمات کلیدی | حسگر های زیستی، پیوند، خواص الکتریکی، دو قطبی۷ شدت میدان الکتریکی |
| لینک مقاله در سایت مرجع | لینک این مقاله در سایت IEEE |
| نشریه | IEEE |
| مشخصات و وضعیت ترجمه مقاله (Word) | |
| تعداد صفحات ترجمه مقاله | 10 صفحه با فرمت ورد، به صورت تایپ شده و با فونت 14 – B Nazanin |
| ترجمه تصاویر | ترجمه توضیحات زیر تصاویر انجام شده و اشکال و نمودارها به صورت عکس در فایل ترجمه درج شده است. |
| فرمول ها و محاسبات | تمامی فرمول ها و محاسبات به صورت عکس در فایل ورد ترجمه درج شده است. |
فهرست مطالب:
چکیده
مقدمه
مدل سیستم
افت توان
الگوی رابطه دو قطب نیم موجی درون بدن انسان
نتیجه گیری
بخشی از ترجمه:
امکان پیوند شبکه گره های حسگر های زیستی به درون بدن انسان برای پایش از دور سلامتی و اهداف درمانی و تشخیصی امکان پذیر است. برای ارتباط این حسگر ها، کانال و یا معبری در بافت بدن انسان موجود است. حسگر ها ها با استفاده از فناوری بی سیم با ارسال اطلاعاتی به صورت تمواج فرکانس رادیویی الکترو مغناطیسی ارتباط برقرار می کنند. این سیگنال ها طی عبور به دلیل این که کانال ارتباطی دارای بخشی از سیال است به شدت کاهش می یابند. برای پی بردن به این میزان افت سیگنال یک مدل افت تکثیر و یا نفوذ از PMBA قبلا ایجاد شده است. این مقاله به بررسی مسافت مناسب بین گره ها برای برقراری بهتر ارتباط می پردازد. دامنه فرکانسی طیف رادیویی ۱ تا ۳.۵ گیگا هرتز برای شبیه سازی متلب مورد استفاده قرار می گیرد. مشاهده شده است که هم چنان که فرکانس سیگنال عبوری افزایش پیدا می کند حد مسافت کاهش پیدا کرده و افت توان بالا می رود. استفاده از الگوی تابش نشان می دهد که شدت میدان الکتریکی با افزایش مسافت کاهش پیدا می کند.
۱ مقدمه
شبکه پیوندی حسگر های زیستی درون بدن انسان از اهمیت قابل توجهی بر خوردار است زیرا امکان پایش سلامتی انسان را از حیث پیش گیری می دهد. یک حسگر زیستی وسیله ای است که می تواند اطلاعات را در خصوص هر گونه تغییر ایجاد شده در یک سیستم زنده شناسایی و انتقال دهد. این سیستم متشکل از گره های مختلف حسگر های زیستی پیوند داده شده در بخش های مختلف بدن انسان برای پایش فشار خون، EGC، پالش و سطح قند خون می باشد. این سنجنده ها با ایستگاه های خارجی و نیز با خودشان(یکدیگر) ارتباط بر قرار می کنند. این مقاله به بررسی موضوعات اصلی در خصوص ارتباط درون بدنی می پردازد که برای کاربرد های متعدد از جمله درمان سلول های رتینای چشم برای نا بینایان دارد. ارتباط سیمی درون بدن به هیچ وجه عملی نیست زیرا کاری بس خطرناک و دشوار (زمان بر) است. این ارتباط حسگر های زیستی درون بدن انسان یکی از موضوعات پژوهشی مهم می باشد زیرا کانال موجود برای این ارتباط یک فضای آزاد نبوده و بافت های انسان که به عنوان یک محیط لزج به دلیل وجود مواد لنفی وسیال می باشند. از این رو افت معنادار در توان عبوری از گروه های پیوندی قبل از رسیدن آن به گره ها(گیرنده ها) رخ می دهد که عمدتا به دلیل جذب توان در کانال بافتی است.
بخشی از مقاله انگلیسی:
Abstract— It has become possible to implant a network of Bio sensor nodes inside human body for remote health monitoring, diagnostic and prosthetic purposes. For communication of these sensors the channel available is human tissue. The sensors communicate using wireless technology, by sending information as electromagnetic (EM) radio frequency (RF) waves. These signals encounter a significant loss during transmission because this communication channel contains a major portion of fluid. To find out this loss, a propagation loss model PMBA has already been developed. This paper investigates the appropriate distance between nodes for better communication. The frequency range of Radio spectrum (1GHz to 3.5GHz) is used for MATLAB simulation. It is observed that as frequency of transmitting signal is increased, the distance limit is decreased and Power loss is increased. Using radiation pattern it is shown that the electric field intensity decreases with increasing distance. Keywords-component; Bio-sensors; implantation; dielectric properties; dipole; electric field intensity. I. INTRODUCTION Implanted network of Bio sensors inside human body is of great interest because it provides remote health monitoring facility, which is significant in terms of prevention. A Bio Sensor is a device that can detect, and transmit information about any change produced in a living system. The system may consists of various bio-sensor nodes implanted at different locations inside human body e.g. for monitoring of blood pressure, EGC, pulse, blood glucose level etc. These sensors communicate with external base station as well as with each other. This paper deals with the main issues of the intra body communication which may be required for various applications such as retina prosthesis for visually impaired persons [1]. Wired communication within the body is not practical to implement, because it becomes a hazardous and time consuming task. Hence wireless technology is used. This communication of Bio sensors within human body is a great research issue because the channel available for this communication is not free space, but it is human tissue, which is considered as a lossy medium due to presence of lots of fluid. Hence a significant loss in transmitted power from implanted node takes place before it can reach the other (receiver) node, which is mainly because of the absorption of power in the tissue channel [2]. Due to presence of this channel the model becomes essentially different from traditional wireless networks in which free space is used as a communication channel. Therefore, the models which have been developed for free space communication need to be modified by taking Dielectric properties of human body into account [3,4]. Calculation of Specific Absorption Rate (SAR) is significant to find out the power absorbed by human tissue. This absorption is directly proportional to the frequency, which results in tissue warming, due to which tissue damaging may occur. In order to avoid this, lower frequency range must be used, but if frequency is lowered, the wavelength will increase, due to which the dimensions of antenna will have to be increased as antenna dimensions are directly related to wavelength [6]. Hence there is a trade-off between frequency and antenna dimensions. For implantation purposes, high frequency RF waves are used, which makes the size of antenna practical for implantation. As power loss in RF signal varies inversely with the distance, therefore it becomes important to calculate the maximum distance between nodes inside the body, so that they can communicate in efficient manner. II. RELATED WORK There has been a considerable research done in energy harvesting techniques in order to provide power to implanted bio sensors, as they must have small but continuous power. Different harvesting technologies for self-powered bio-sensors, including conversion of nano scale mechanical energy into electrical energy and use of hybrid cell for solar and mechanical energies are discussed in [5]. Implanted network of Bio Sensors can provide expanded health care services for persons who require continuous monitoring. These networks require a technological platform as well as algorithms which must be time sensitive and must avoid packet collisions in wireless environments. The use of 978-1-4244-3709-2/10/$25.00 ©2010 IEEE implicit Earliest Deadline First policy is recommended in [8] to reduce congestion in network traffic flow. As these networks are fundamentally different from those working in free space, so energy utilization must be accomplished in an efficient manner; So that, the network works on minimum possible energy. Two different energy efficient communication protocols, namely cluster-based and tree-based protocols are compared and analyzed that are designed to reduce energy consumption [7]. The analysis shows that the cluster-based protocol has better energy performance. Propagation of EM wave in a medium mainly depends on its dielectric properties. The dielectric properties of body tissue have been investigated in [3] to determine pathway of current flow inside the human body. The propagation loss model for intra body communication of Bio sensors network has been developed in [2]. However the appropriate distance between sensors for effective communication has not been discussed. In this paper, the goal of our research is to find out this distance, and variation of electric field intensity with respect to distance. III. SYSTEM MODEL For simplicity, this paper considers only two implanted bio sensor nodes connected with elementary oscillating (Hertzian Dipole) antenna used for transmission and reception of RF waves. The length of the dipole is the main determining factor of the operating frequency of the antenna. One reason for using dipole antenna is the fact that even though the Hertzian short dipole is very small in size, its effective aperture is comparable to antennas which are many times larger than it [4]. One way to overcome the body losses during implanted communication is to make an efficient transmitting antenna. Due to practical constraints, antenna should be of very small size, i.e. in order of a few millimeters, which is another reason for using small dipole antenna for this model. A very small portion of tissue surrounding antenna is considered so that tissue can be considered as homogeneous medium, so that it can be considered that power loss is not due to scattering or diffraction, but it is mainly due to absorption by tissue. As the channel for this communication model is human tissue, therefore dielectric properties of human tissue i-e conductivity, permittivity and permeability must be considered [4]. The channel around the transmitting antenna is bifurcated in near-field and far-field regions, because the power loss in the near field depends mainly on H-field and in the far field, it mainly depends on E-field. In general, it is considered that far field starts from the distance which is larger than the wavelength used. In this field, both components of the electromagnetic field become perpendicular to the direction of wave propagation. Therefore, power loss is calculated by using different equations which are derived using Maxwell equations of E and H-field inside a lossy medium [1]. The extent of near field, for short dipole it is given by / 2 o d = λ π .
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دانلود رایگان مقاله انگلیسی + خرید ترجمه فارسی
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| عنوان فارسی مقاله: | تجزیه و تحلیل و شبیه سازی مدل تکثیر برای ارتباطات بی سیم حسگر های زیستی |
| عنوان انگلیسی مقاله: | Analysis and Simulation of Propagation Model for Wireless Communication of Bio-Sensors |
| برای دانلود رایگان مقاله انگلیسی روی عنوان انگلیسی کلیک نمایید.برای خرید ترجمه آماده ورد، روی عنوان فارسی مقاله کلیک کنید. | |
