Russia, Saint-Petersburg, “MEDI” Joint-Stock Company, medi@medi.spb.ru

The medical digit-system with digital video and radio diagnostics for the first time developed and implemented into the out-patient dental practice of MA "Medi" allows optimizing of the diagnostic process as well as realization patients consultations and uninterrupted education of dental doctors at a distance. Consultations in the real time mode and "postponed" consultations are discussed.

Россия, Санкт-Петербург, ЗАО “Меди”, medi@medi.spb.ru

Впервые разработанная и внедренная в амбулаторную стоматологическую практику MA “Меди” Цифровая Медицинская Система с дигитальной видео- и рентгенодиагностикой позволяет не только оптимизировать диагностический процесс, но и осуществлять консультации пациентов и непрерывное обучение врачей- стоматологов на расстоянии в режимах on-line и off-line.

In recent years the analog channels of information transfer have been replaced by digital ones, the global net communications have been spread widely. Technical problems on the way of telemedicine development can be solved successfully on the base of advanced informative technologies and the modem computer equipment. The principle peculiarity of digital medical systems consists in that they are able to transmit medical information without any loss of quality. Depending on possibilities of a telecommunication tools and the tasks to be fulfilled the consultations can be performed either in the mode of a real time or in the mode of "postponed" consultations.

The digital medical system (DMS) of "Medi" joint-stock company is a part of a corporate information system, which includes the following basic components:

• hardware with computers and office equipment;
• operating systems and database management systems;
• network software and hardware;
• application software;
• telecommunication systems.

A valuable DMS is able to function only in case when all the basic components of a corporate informational system have been implemented and can support the enterprise life cycle. The DMS based on the available hardware and software suggests a creation of specialized databases and applications. If the system is suggested to function under the presence of enterprise affiliates, the critical role should be given to the use of modem telecommunication systems.

To transmit the data between the remote affiliates and the central database, the technology of ISDN (Integrated Service Digital Network) has been selected. The ISDN is a commutative digital net, which allows making calls or transmit the data and the video-images through a united network interface with the rate of 64 kb/c for every informational channel. The use of this technology gives the possibility to treat affiliates as a part of a united informational infrastructure, to organize a highly effective and active connection, to perform consultations in a real time mode.

The DMS of the "Medi" joint-stock company is composed of a base segment of computer network connected with segments of affiliates and clinics.

The base segment of the computer network includes work stations of the central diagnostic radiology room, work stations of the largest "Elite"-clinic, servers for keeping and copying the databases and computers of support services. Equipment of the central diagnostic radiology room includes:

1. Work stations of a radiology-consultant physician and of an X-ray technician equipped with computers owing a special software and a scanner which allows the scanning of radiograms with a sufficiently high resolution.
2. Specialized dental radiological complex. The database servers have high-rate disk storage of large volume; the system of reserve copying supports the generation of copies given by a specialized schedule.

The central clinic has seven rooms equipped with personal computers and with three movable radiovisiography stations "Trophy". The network equipment maintains the data transmission with the rate of 10 Mb/sec and 100 Mb/sec. High rate channels are used for exchange the data between the work stations and database servers.

DMS segments of standing-off clinics and branches are connected with the central segment by means of a digital commutation. The number of work stations in clinics varies depending on the class of the clinic. The digital connection supports the transmitting of data with the rate of 64 kb/h, which is sufficient for performing consultations either in the mode of a real time or in the "postponed" mode.

For keeping the patients records of the central diagnostic room the specialized program "Roentgen" is used which allows the patients' data input, keeping history and kinds of examination, keeping the records of diagnostic X-ray-examinations.

Use of various equipment for gathering the data of individual patients in local unconnected database systems arises the problem of informational integration in a united network database.

Within the system of "Medi" dental clinics the movable computer radiovisiography stations "Trophy" are applied. Every "Trophy" station has its own local database and special software. Electronic patients cards application is used for data integration when patients are registered in these different local databases. Thus this application is a connecting-link that accumulates all patient data. The electronic cards contain the orthopantomogram images, aimed pictures, video information received by digital video cameras. While using the system of electronic cards, the doctor is always able to compare visually the diagrams of performed treatment and the planned ones. He also can analyze the dependence of treatment results on the concomitant patient's diseases, look through the video and radio graphs, gather the statistics of performed treatment, exchange the experiences with colleagues. Thus the base of knowledge is formed containing a structured information on treatment of a great number of patients including the data on radiology examination and video information. Creating this base is the most topical task now, when the system of dental clinics works on unified technologies. The importance of that kind of base hardly can be overestimated.

Thanks to digital techniques some principally new facilities of processing and getting information transmitted by radiation appeared. One of the striking examples of these facilities is the computer processing of radiograms. Digital processing methods with their inherent precision and flexibility and the modem hardware as well defined the increasing role of digital methods in comparison with the analogue ones.

The "Neuron Vision" system is designed for realization scientific research in semiautomatic mode. The special structure of sign description of areas, textures and objects has been developed. It allows composition of most complete conception of the examination subject on a modem scientific level. The system can be used for a complicated scientific research associated with image analysis and for fulfilling the stream of standard image operations as well.

By means of "Neuron Vision" signs vectors can be received. They describe the geometry of binary objects and halftone areas as well as densitometric and textural features of halftone areas. Geometrical signs of an object include the signs presenting the geometry of the object, i.e. it's surface area, perimeter, form factor etc. Densitometric features of an area include the signs received from measures of optic densities. They are the integral optic density, dispersion of the optic density, etc. For image areas having a regular structure of pixels location with definite values of optic density the texture signs are used.

Measures can be carried out in an automatic or an interactive mode. Interactive measurement mode is possible on binary or halftone images. Mode of automatic measurement suggests performing the measures of coupled images: a binary image and a halftone prototype.

The mode of consultations is determined by the presence of necessary telecommunication equipment and by tasks to be resolved.

The digital connection provides enough rate for performing consultations in the on-line mode, i.e. in the mode of a real time. At the time of diagnostics the doctor being in an affiliate uses program tools of TCS (telecommunication station). Doctor selects an image to be consulted and informs the TCC (telecommunication center) about readiness to perform the consultation. The information can be transmitted by phone or by e-mail. The radiology- consultant physician establishes connection with remote computer and starts a cooperative image processing using a common access to the resources of TCS. In case of performing the teaching consultations the TCS-doctor does not participate in the processing. By means of equipment of the consulting doctor, the physician of the telecommunication center carries out analyses pictures, performs required measurements, writes conclusions, performs pictures rejection. Comments are transmitted by phone in the mode of a conference or by microphone as well as directly by computer by means of a message editor. Connection session in the online mode is presented on the figure.

When the consultation with affiliates clinics owing no digital connection channels is required, standard equipment is used which allows sending the image by e-mail. A regulation mode of transmitting the electronic cards permits to perform the delayed consultations on a base of the most complete radiological and video information of a patient.

The affiliates that have access to Internet can apply the mode of consultations in a real time without possibilities of synchronous image processing. Common resources of WWW-servers are used to perform these consultations. In this case consultations are held in a question- answer-mode with a simultaneous review of video information by TCS-doctor and by consultant-physician as well.