Prototype System Design For Telemedicine Using Fixed WIRELESS INTERNET - Seminar Paper

Prototype System Design For Telemedicine Using Fixed WIRELESS INTERNET
With the day to day improvement in the field of medicine the urban society is enjoying a healthy life, but for the people of rural and remote areas even the basic health care is not sufficiently available. For the rural masses to enjoy the breakthroughs in the field of medicine, 'Telemedicine' can be used. The present form of telemedicine does not suit the Indian scenario due to the described factors. To make telemedicine suitable for Indian conditions we design a low cost, efficient prototype system making use of fixed Wireless Internet. In our system we connect the remote or rural areas to the nearest well established hospital through the Fixed Wireless Internet. In the rural center, less trained medical attendant can work upon patients by the guidance given by the efficient doctor guiding him through the fixed wireless Internet. The basic structure of our Telemedicining is achieved through a digital camcorder and VoIP enabled telephones, which are both compatible with Fixed Wireless Internet. For the effective performance of the Fixed Wireless Internet system the design criteria of the transceiver is of utmost importance. The use of Fixed Wireless Internet System as a bridge solves the problem of Band -width requirements and cost effectiveness. With these Telemedicine system remote consultations, monitoring is possible. Depending Upon the infrastructure and the Personnel available in the rural center, telesurgery can become a reality.
Recently, the United Nation's Human Development Report 2000 was released which has praised India's human rights endeavors. In the same report, it has also been stated that the rural health profile of the country is disturbing. When the researchers are creating the map of chromosomes, the doctors in US using 'biochip', many people, from our rural India die because of unavailability of proper medical facilities. Besides the lack of willingness from the practitioners side, the paucity of health related data is a major handicap in providing medicinal facilities in a developing country like ours, having overburden of population and financial constraints. Moreover India is undergoing a demographic transition and the age groups of the older are growing faster than the age groups of the younger. Today India counts over 70 million elderly people. Approximately 7% of the Indian population is over 60 years of age. 75% of these elderly live in rural regions and 20% are disabled to varying degrees. The average life expectation of a person born today is around 62 years. But the sad realities in India show that the greater the longevity, the higher the chances of disability and frailty. The fact that most of the government sponsored old age homes are located in urban areas clearly shows that elderly citizens of rural area do not receive proper care. It is also difficult to take them to efficient urban hospitals due to our 'kachha' roads.
Communication and computers have brought about technological wonders in all spheres of life, altering the living style of people. Information super-highway has really made the world a 'global village' with the help of innovations taking place both in hardware and software and in the transmission medium. All the development activities center around urban areas. We would like to utilize the technology marvel to deliver 'Medical Care' to reach the needy rural masses with the help of telemedicine.
Telemedicine has the potential to perform this task more ably and thus profoundly change the health status of rural India.
Rural Center
It provides entry for patients into wireless telecom network. It comprises of all system, which digitize data from lab instruments that can be sent to a Hi - Fi hospital that is connected through Fixed Wireless Internet. In the rural center, the digital camcorder records the patient's image, which is digitized and fed to the computer interface. 

              Hi - Fi Hospital
It provides entry to telemedicine for health care provider. Here the physician accesses information from the rural center and can also access database and reference information simultaneously. It includes two way voices; video, which allows the physician to monitor and communicate with the person who, is in the rural center with the simultaneous transfer of digitized data.
VoIP enabled phones empower both the patient as well as the doctor to have effective conversation with each other.
Digital camcorder is provided in the hospital so that the patient in the rural hospital can also see the image of the doctor. Hence the patient can have face to face conversation, which gives a feeling that the doctor is physically present. This helps to develop an enhanced doctor - patient relationship, which the Indian patients look for. VoIP Enabled Phones:
We make use of VoIP enabled phones so that our system is compatible with Fixed Wireless Internet network.
The DSP in VoIP is responsible for signal processing functions such ac analog to digital conversion of voice signals, voice compression, echo cancellation and voice -activity detection call origination, call detection, signaling.

>       Signaling in VoIP network is accomplished by exchange of IP datagram messages between the components. The format of this message is covered by the standard data link layer protocols.
>       In VoIP digitized voice is bundled into IP packets and sent out into the network for delivery. Routers, Switches and other network equipment direct the packets to their destination IP address.
>       In addition to performing the analog to digital conversion, the CODECs compress the voice data stream. Compression of the voice wave form results in bandwidth savings. The output from CODECs is a data stream that is put into IP packets and transported across the network to an end point. The end points must use the same standards as well as common set of codec parameters. Use of different parameters at the end points will lead to unintelligible communication. Use of complex coders with higher compression ratios reduce the band width consumption. But there is a price paid for the conversion: increased conversion delay. > Another way to save bandwidth is the use of silence suppression, in which voice is not sent between the gaps in human conversations. The voice-activity detection technique allows the monitoring of silence in speech data.

Advantages of VoIP
S Reduced cost
S Compelling technical advantages over circuit switching
•   Based on open architecture, hence more interchange able and more modular.
S Is suitable for computer telephony integration.

Digital Camcorder
The raw content is obtained by filming video instructions already captured on tape to digital format using a graphics card and A/D converter. The raw video content is edited and compressed and then saved in a format in which it is eventually distributed.
It incorporates software with limited editing capability and save video files to standard formats, such as 'avi' and 'mpeg'.
Once digital video scenes are created and edited, a range of file format options are available for storing and distributing images. Delay can be minimized by using file formats that optimize the media and retain quality, which the smallest possible file size. File sizes should be small and streamable to eliminate delays wherever possible.

Fixed Wireless Internet
With highly reliable RF transmission systems, it has been made possible to build economical, high-speed Fixed Wireless Internet networks. It acts as a bridge in linking the rural center with the Hi - Fi hospital. The bridge includes hardware and software of telemedicine as well as the wireless system design. It enables the transmission of higher resolution pictures of patient injuries and X - rays for consultation and opinion. The system facilitates anything from large e-mail attachments to interactive medical examinations. Working
The computer would digitize the voice and set up an Internet protocol address which packets the data. The packet signals are converted into RF signals. Spread Spectrum technology is made use of so as not interfere with the other frequency bands existing.
Design of Fixed Wireless Internet System
The design of Fixed Wireless Internet is the most important aspect in our system as it is unique, supporting the kind of bandwidth required for sophisticated operations in our country in a cost efficient manner. So utmost care is taken in the location and design of transceivers i.e., antennas and receivers. Once the design of Fixed Wireless System is taken care of in the physical layer, the information flows in familiar well-defined protocols through the data link and network layer and layers above them.

Antenna Design
The design and position of antenna, both for hospital center and rural center is a critical criterion for the efficient and successful working of the system. Higher gain antennas with narrow beam are made use of in our system. This reduces the interference transmissions from several remote stations. Line Of Sight
For Fixed Wireless Internet Network to work an unobstructed LOS is needed in between transmitting and receiving points, but practically it is no possible. Following criteria are taken in to consideration for the location of transceivers.
A series of imaginary concentric circles around direct LOS between two transceivers are drawn.
Those that fall within the first circle, known, as the first Fresnel zone is the most serious. For a reasonable loss less communication there should be no obstructions within the 0.61 times the radius of First Fresnel Zone at any point between the transceivers.
Based on the above criteria, assuming that our system operates at 2.4 GHz with transceivers placed at a distance of 10 Km apart, reliable communication depends that there are no objects at mid point lying within 10.59 m of LOS.

Receiver Location
Location of receivers in high frequency Fixed Wireless Internet systems is subject to quirks of environment, multipath fading is the most important of them. Seasonal changes in refractive indices of atmospheric layer will give rise to multipath fading.

Multipath Fading
The different atmospheric layers having different refractive indices cause it. It tends to manifest itself as a narrow band notch that moves dynamically through the received power range causing severe bit error rate.
To reduce effects of selective fading and to improve the path reliability three methods can be used:
a.    Space Diversity, in which two antennas are spaced slightly to transmit the

same message at different times.
b.    Frequency diversity, in which the same message is transmitted at two different

c.    Different Polarization's.
Under these circumstances the receiver must be designed to pick up the more reliable signal.

Features of Fixed Wireless Internet
S Higher reliable communication with enough bandwidth to deliver video signals
high-speed data as well as VoIP. •   Design, installation and operation are much simpler and cheaper than the
conventional wired local loops and optical fibers. S Makes use of spread spectrum technology so as not to interfere with other existing
frequency bands.
S 2.4-2.4835 GHz band can be made use of, because it is unlicensed and no fee is required for its use. The use of 2.4GHZ has been made possible because, recently IEEE has made it compatible with 802.11b.This allows the use of 2.4 GHz for long transmission distance with data transmission at the rate of 11MBps, fulfilling our requirements.
S Transmitted power can carry signals as for as 50 Km from the transmitter, but the
receiver must lie in the Line Of Sight. S Using extra amplifiers to boost up the transmission can increase distance.

Our prototype system addresses the technical requirements for the efficient implementation of telemedicine in India. In future all the hi-fi centers can be connected through Ethernet. This enables the rural center not only to access the hi-fi center to which it is primarily connected through Fixe wireless Internet, but also to more than one hi-fi centers. Thus saving money, time to rural people and giving access to all the medical facilities that urban people enjoy. We hope our system is brought into practical implementation in near future. So that more lives of the people in rural India can be saved.

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