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Ricerca>Progetti>Live-For-All>Initial
proposal and goals Project Title LIVE-FOR-ALL Date November 4th, 1999 Participants to the Project Project manager and principal investigator Dr. Michele Crudele Medical Informatics Laboratory Libera Università "Campus Bio-Medico" di Roma via Longoni 83 I-00155 ROMA tel. +39-06.22.54.13.60 fax +39-06.22.54.14.56 m.crudele@unicampus.it http://crudele.unicampus.it Other investigators Flavio Fulciniti Multimedia expert Via F.Massara, 18 I-88100 Catanzaro Tel. +39-09.61.77.44.27 f.fulciniti@tiscalinet.it Marco Venditti Telecommunication expert Information Systems Department Libera Università "Campus Bio-Medico" di Roma via Longoni 83 I-00155 ROMA tel. +39-06.22.54.13.58 fax +39-06.22.54.14.56 m.venditti@unicampus.it Summary In modern medical teaching the operating theatre procedures play an important role. There is a common limit to the availability of operating rooms for students: space is never enough. The use of video transmission to other sites, such as classrooms, has been spreading in the last years, but it requires point-to-point connection, lacking flexibility. The recent advancements in digital video encoding and streaming video technology make now possible to deliver high quality moving images and sound to a LAN. Personal computers are ubiquitous and allow anybody to access a live transmission in any room. For live transmissions, multicasting saves bandwidth if there are multiple users. Milestones
Background In "Campus Bio-Medico" University of Rome the Medical Informatics Laboratory started two years ago a research plan dealing with streaming video technology for educational purpose. So far the full Anatomy video course for medical students has been digitalized and is available on any PC of the students' laboratory. It is based on an HP Netserver running WindowsMedia server and delivers on-demand video clips encoded at 500 Kbps to HP Vectra clients. The quality has been judged good by professors and students. Some of the nursing training videos have been also encoded and are available, with a content index, allowing direct access to internal parts. Activity Description Set up of operating theatre video infrastructure The first step is to provide the operating theatre with a permanent video production infrastructure. Cameras will be installed in the lighting devices in order to point directly to the operating field. An omni directional ambient microphone and a radio controlled one, according to the specific needs, will be used. Set up of encoding system and quality tests The audio and video signals can be digitalized locally by installing appropriate equipment, or remotely, using an existing video connection to the Medical Informatics Laboratory. The last solution would simplify the handling by not requiring a technician in the operating theatre. The encoding machine needs to be a double processor to reach high quality levels. Our experience with Anatomical videos shows that a good quality at 352x288 size 15 fps can be reached by coding at 500 Kbps with a Pentium 400 MHz. Higher bandwidth means higher quality and we are aware that for live operations and detail examination we should be able to encode at 1024 Kbps. This requires higher processor power. Using a HP Kayak 2x300MHz we were able to achieve more than 2000 Kbps encoding. Our attempts to use full screen 640x480 or 704x576 failed both for the insufficient processor power and for the capture card performance. A 2x550 MHz machine and a new generation capture card would give us all the processing power to test the highest possible quality and choose the best cost/performance solution. We have to consider also the available bandwidth on the existing 10 Mbit LAN and the possible migration to 100 Mbit. We are going to use Microsoft WindowsMedia technology because it allows us to overcome the 1024 Kbps limitation, typical of RealSystem's encoder. Moreover, RealEncoder does not yet support double processors. Set up of video server The video server will be set up on a Windows NT 4 machine, later updated to Windows 2000 as soon as the WindowsMedia server software migrates to that operating system. The connection between the encoding machine and the video server is through LAN. Even though the full Campus network is 10 Mbit, we are planning to use 100 Mbit switches for the server, the encoder and the connection to all the most frequent users' locations. Performance tests of unicast transmissions to classrooms Performance tests will be undertaken to verify the upper limit for the number of concurrent users. In the first phase users will be always grouped in classrooms, watching the event on a wide screen, in order to minimize bandwidth on LAN and also for tutorial support. We'll evaluate the need for a feedback to the surgeon in the operating theatre. Questions could be asked by attending students. A tutor in the classroom should answer them, but we'll provide a textual interaction. Therefore the tutor will be able to pass a specific request to the surgeon, by typing the question. A technician or a nurse in the operating theatre will read the question and formulate it to the surgeon, who will be able to answer vocally. Set up of multicast infrastructure The final goal is to transmit to different locations in the University campus, which means that many concurrent users may be watching the same live feed. LAN bandwidth can suffer significantly if we are going to use 1024 Kbps streams. Only 8 users would overload the 10 Mbit Ethernet available everywhere. Two solutions can be applied. The first is to raise to 100 Mbit the whole network. It means changing all the hubs or switches, which do not comply with the new standard. This procedure would allow tens of concurrent users, but would also generate a lot of traffic, which may disturb other bandwidth hungry applications, such as image file transfer from the Radiological department. The second solution is to enable multicasting. Through multicasting we are able to use only one stream, so that each client uses 1024 Kbps. In order to enable multicasting, switches must replace hubs. It is not possible to change them immediately all over the places; therefore we'll set up the multicasting infrastructure only with the most frequent used locations, allowing other users to utilize unicasting transmission. The most effective balance between these modalities will be studied. Start of routine transmission By setting up an easy procedure to start a live transmission, daily use of the operating theatre multicasting will be possible. Our goal is to minimize the impact for the surgeon and all the personnel in the operating room. Final assessment During all project phases, assessments will be run, with interviews and questionnaires to physicians and students in order to increase the quality level. A final assessment will provide clues to future enhancements and related projects. Publication of the results This proposal is available at http://research.unicampus.it/live-for-all Ongoing process and results will be published on the same site. | |||||||||||||||