A reliable multimedia communication network that links the remote centres with hospitals is essential. The delivery of multimedia content in a timely fashion is very important. The key is to find a method of delivery that is universally acceptable, easy to use, and reliable. The answer comes from the Internet. The Internet offers a developer the ability to publish information very quickly. It provides a widely used and uniform communications medium to link users together to access or deliver multimedia information. However, while using mobile devices and the Internet as vehicles for multimedia delivery and interaction, the following factors are to be taken into account:
The application requirements can range from a very simple radio to very complex real-time image/signal processing system
Text requires the lowest bandwidth, while audio and video data and signals require a significant increase in bandwidth. Specification of bandwidth to be used and compression techniques used are to be laid down so that the data and images that are transmitted are of diagnostic quality. The following issues arise in using networked communication:
Choice of equipment and bandwidth management for fast, reliable, and secure transmission of patient data.
Bandwidth determines the information capacity of a network per unit of time. Wireless networks deliver lower bandwidth than wired networks. Hence software techniques based on compression should be used. Also scheduling communication intelligently can save bandwidth. For use in telemedicine, the techniques should be extremely reliable. Current cutting-edge technologies are yet to develop. Bandwidth requirements along with applications are given in (approximate) logarithmic scale in Figure 1.
Three common technologies used are (bps = bits per second; K= Kilo; M= Mega; G = Giga):
Dial-up mode: Rate 28.8 Kbps
T1: 1.544 Mbps
DS3: 45 Mbps
As an example, standard X-ray transmission takes 30 minutes in dial-up mode, 30 seconds in T1 mode, and 1 second in DS3. It is obvious that the cost goes up as we want to increase the bandwidth to communicate voice, data, and pictures.
As mentioned earlier, even a low-cost dial-up mode can be helpful in telemedicine. Of course the more sophistication we introduce the more complex and costly the system gets, and the system has to be supported by governmental agencies or health insurance providers.
DS3 is a dedicated, private line service designed for point-to-point communication. This service uses fibre- optic cable. One can have the option of tiered DS3 service from lower to higher bandwidth from 5 Mbps to 45 Mbps, depending upon cost considerations and transmission requirements.
We need a proper choice of graphics and audio equipment for quality images and audio for diagnosis.
Low-cost workstations are to be made available at the user 's and health provider's end. Suitable software and hardware are to be developed so that the workstations are easy to use by doctors , nurses, and other paramedical staff. For this purpose, suitable training centres are to be made available.
Low cost per consultation, faster diagnosis, faster reply to queries, and quicker medical aid when compared with the conventional method of a direct visit to the doctor.
Quick evaluation of emergency cases and arrangement for transportation to hospitals supported with mobile telemedical personnel and equipment.