13   Medical Applications

The following projects were carried out during the year 2005:

Employees of Masaryk University in Brno and the 2nd Medical Faculty of Charles University in Prague were directly involved in the activities. Specialists from the following institutions participated in the implementation of the individual projects as members of working groups and in the preparation of the joint projects for the next period: EuroMISE (a joint facility of the Academy of Sciences of the Czech Republic and Charles University in Prague), Constitutional Court in Brno, Brno University of Technology, St. Ann's Teaching Hospital, Thomayer Teaching Hospital, Central Military Hospital, Masaryk Memorial Cancer Institute, Masaryk Hospital in Ústí nad Labem, Palacký University Olomouc, Charles University, Na Bulovce Teaching Hospital, Hospital in Znojmo, Municipal Hospital in Litoměřice, Hospital in Hořovice and the Medtel o. p. s. company. Specialised hardware and software was developed in cooperation with companies TatraMed spol. s r. o. from Bratislava, IMA s. r. o. and Intercom Systems a. s. from Prague.

13.1   Standard Environment for Medical Applications

A basic internal paper entitled "Selected legal aspects of the management of medical records and telemedicine from the Czech and European point of view" was created during the first half of the year as a result of cooperation with the EuroMISE centre of the Institute of Informatics of the Academy of Sciences of the Czech Republic. Further work on this task was started as of 1 October 2005 in the form of a PhD thesis in Biomedical Informatics at the 1st Medical Faculty of Charles University. The topic is "Legal aspects of electronic communication in telemedicine" and its supervisor is also the leader of the Medical applications activity. The possibility of consultations with P. Mates, JD, from the University of Economics, who specialises in this issue, is also important.

13.2   Medical Applications Related to Grid Technology

Further development in the area of medical applications related to the Grid technology was coordinated within the MediGRID project of the Informational Society programme of the Academy of Sciences. We cooperated with two other international projects, EuroCareCF (research of cystic fibrosis, a genetic disorder of multiple human tissues) and MedGeNet (support for the research of thalassemia, a genetically determined hematopoietic disorder). After their respective contracts will have been signed, further research will follow as a part of the Virtual collaborative environments focusing on the required technological support.

13.3   Medical Applications within the Framework of the CzechLight Project

The original aim of creating a communication infrastructure for the Cell Therapy Centre was affected by delayed delivery of optical connectivity to the key locality FN Motol due to the clash with the construction of a new power centre in the hospital. Migrating the hospital network infrastructure from ATM to gigabit Ethernet technology proved to be another limiting factor by the end of 2005.

A similar situation occurred in the case of the originally planned integration of the three teaching hospitals in the Prague area into a single communication unit. Complications arose due to a change in the management of the health care system in Prague that resulted from the changes at the Ministry of Health of the Czech Republic. The original intention to interconnect the General Teaching Hospital at Karlovo náměstí (Charles Square) with the Teaching Hospital Na Bulovce and Thomayer Teaching Hospital in Krč into a single "virtual" network had been pursued for approximately one year. During this period, activities were started with the goal of establishing an infrastructure with sufficient data throughput between these interconnected hospitals. The change in the health care system occurred immediately before signing the relevant contracts. Now the hospitals are returning to the model of independent operation.

Further developments of the communication infrastructure are described in the chapter Optical networks. This section includes only information that is special to the medical applications themselves. The available infrastructure allows for many different experiments and applications, but we will focus only on two of them.

The first important area are specialised consultations. Of all the hospitals connected, Thomayer Teaching Hospital (TTH) showed strong interest in neurosurgical consultations by experts of the Central Military Hospital in Střešovice (CMH), as they treat complicated polytrauma patients - most often victims of car accidents - and lack their own neurosurgical team. They often face decisions as to whether to continue the treatment by means of trauma surgery or to pass the patient to the department of neurosurgery for urgent operation. Their requirements on consultations pose many logistical problems. For one, data transfers must be sufficiently fast and reliable but, on the other hand, sensitive data about patients must be handled in a secure way. Another strict but understandable requirement expressed by the specialists in CMH is that the consultations for TTH should not become an excessive burden for them. Physicians therefore need to be able to process the images to be consulted in their own standard environment. In terms of hospital information systems, it is in fact an upload system, when the images coming from TTH are placed in CMH's system, as if having originated from a specialised department of CMH. The basic diagram of this interaction is shown inFigure 13.1.

[Figure]

Figure 13.1: Remote consultations

As mentioned in the chapter Optical networks, both TTH and CMH were connected to the CzechLight network through gigabit links, both of them terminated at the CESNET headquarters in Prague-Dejvice. This way we resolved the first problem of the pilot operation - insufficient connection speed for specialised services. This was especially important for transferring computed tomography sequences (CT) that are needed for examination in neurology and neurosurgery, where a 100 Mbps link connecting the site was often found insufficient. Given the life-threatening conditions, the data transfer must be fast and reliable. As a precaution for sites with unreliable or slow connectivity, the image is also sent via ambulance. Of course, this causes a delay in the image evaluation ranging from 30 to 45 minutes, depending on road traffic conditions.

The second important application is image data archiving, which is demanded by hospitals that are already well equipped with film-free data processing technology. So far, each hospital has its own central data repository that can only be accessed from their local network. The MeDiMed project introduced certain elements of data distribution across WAN, be it for backing up data or creating specialised databases for research or teaching purposes.

In general, though, the peer-to-peer model for exchanging digital image data between remote hospitals seems to be preferable. An example is a project involving again the Central Military Hospital in Prague-Střešovice and the Masaryk Hospital in Ústí nad Labem (MHUL). The hospitals have to exchange their image data regularly in order to provide mutual backup. This task is more complicated in that it means a systematic cooperation in building and administering a data archive rather than a simple transfer of individual examinations. The procedure is approximately as follows: every day during off-peak business hours, the active parts of the data archive are replicated not only inside each site but also to the repository of the cooperating hospital. This means a substantial increase in the reliability of stored data and resilience against failure of either cooperation centre and also decreases the impact of regular maintenance tasks. As an important side-effect, of course, it also means easy data sharing for the purposes of medical research. The block diagram of the proposed solution is shown in Figure 13.2.

[Figure]

Figure 13.2: Distributed archiving system

Both sites will be equipped with FCoIP (Fibre Channel over IP) hardware, which handles protocol conversion, data encryption and transfers over distances exceeding usual metropolitan links, where issues with timing and delays may arise.

For metropolitan distances (up to 20 km), we intend to test the connection of disc arrays via Fibre Channel over DWDM links. We believe that the use of the DWDM system is a very suitable solution in this case, as dedicated optical fibres are usually prohibitively expensive in urban areas and use of the IP protocol leads to many technical complications and security concerns.

13.4   Development of the MeDiMed Project

The MeDiMed project is progressing in many directions. We started negotiations with Masaryk University and Masaryk Memorial Cancer Institute (MMCI) aimed at connecting the Masaryk Hospital in Ústí nad Labem (MHUL) to the central communication server PACS (Picture Archiving and Communication System). MHUL has a special interest in the area of oncology (transfer and evaluation of image data), where MMCI is the ultimate national authority.

In cooperation with the Teaching Hospital Na Bulovce and Charles University, we started the development of unique methods of merging image information from different sources, such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This approach uses state-of-the-art graphic processing algorithms and enables, for example, recognition of low density objects (vascular structures shadowed by bones) or modelling inner parts of joints.

Processing multidimensional models from real time image modalities is another project that enhanced the original plan of activities. This project is implemented using the central communication server PACS and CESNET infrastructure. The participating institutions are St. Ann's Teaching Hospital in Brno and the Department of Computer Graphics and Multimedia of the Faculty of Information Technology, Brno University of Technology.

Modern medicine increasingly employs various technologies and devices that allow for improving the quality of diagnostics and treatment of patients. Diagnostic imaging methods, such as Computer Tomography (CT) and Magnetic Resonance Imaging (MRI) are good examples. These techniques provide three-dimensional rendering of internal structures inside patient's body. However, evaluation of 3D images depends, no less than with 2D X-ray images, on a subjective judgement of the examining physician. One of the modern trends in this area is 3D modelling of tissues based on CT/MRI data and application of these models in clinical practice, e.g., for planning surgical and reconstructive operations, simulated surgery, navigation and aiming of instruments, realistic training of physicians on simulators, and so on.

A joint project of the Department of Computer Graphics and Multimedia of the Faculty of Information Technology (Brno University of Technology), Clinic of Imaging Techniques of St. Ann's Teaching Hospital in Brno and CESNET performed first experiments in the area of CT/MRI-based 3D modelling of human tissues. The project team proposed a clinically applicable method for 3D computer modelling of human tissue based on CT/MRI data. In addition, applications are being identified and prepared in order to introduce these methods in the clinical practice of many fields of medicine, such as orthopaedics, plastic surgery, dentistry, and others.

By its nature, it is a highly interdisciplinary undertaking that uses advanced knowledge of medicine, information technology, mechanical engineering and other disciplines. It is very difficult (in terms of financial, human and technical resources) to build an integrated facility that would be able to pass the research results effectively to the clinical practice. To this end, we started building the "virtual development and application workplace". The basic idea is to enable specialists to cooperate in this workplace without leaving - both physically and administratively - their parent organisations. The same applies to the sophisticated technical equipment (CT, MRI, 3D printer, graphic workstations, and so on). All data and communication integration is provided by the CESNET2 network.

Thanks to the existing network infrastructure with secure transfer of sensitive data, professionals (physicians or technical engineers) need not travel to remote facilities that are dispersed throughout the entire city. Transfer of CT/MRI data from hospitals to the technical workplace, segmentation of tissue images, preparation of 3D models, verification of their accuracy, and so on, is negotiated, authorised and performed through the CESNET2 network. This can be of crucial importance for human health and life in acute cases, when time is the key factor. It also enables better utilisation of the precious time of highly qualified specialists and capacity of sophisticated and expensive technical equipment (CT, MRI, 3D printer, and others). In addition, this "virtual workplace" can also be easily extended by adding more clinical or technical sites at the regional, district or national level.

[Figure]

Figure 13.3: The initial shape of a face with a visible damage of tissue

[Figure]

Figure 13.4: Reconstruction based on the principle of symmetry

[Figure]

Figure 13.5: The final complement used for reconstruction

13.4.1   Electronic Signature in Transferring and Processing Medical Image Information

The Metropolitan Centre for processing of medical image information developed by the MeDiMed project uses technologies based on the DICOM (Digital Image Communication in Medicine) global communication standard. The issue of secure transfer of medical data, including authentication of users, inside the local network of a single hospital is usually addressed by the respective PACS vendor in cooperation with the supplier of the hospital system, without any ambitions to solve the compatibility requirements reaching beyond that particular health care facility.

Implementation of the authenticated access to medical image data among different health care facilities cooperating in the MeDiMed project brings a new quality of services provided, in particular support for the transfer of image information between multiple sites (hospitals) visited by the patient during the treatment, or information needed for the consultations of specialists. As a consequence, it clearly helps and accelerates the determination of an accurate diagnosis, eliminates repeated examinations, and saves the time of both patients and physicians.

The devices from various manufacturers that are currently connected to the metropolitan PACS server (visualisation workstations, specialised workstations for primary diagnostics or archiving, therapeutic devices etc.) form a highly heterogeneous environment. Access from individual workplaces is now controlled by means of client IP addresses or rather their mapping into the private address space of the metropolitan PACS VPN. This solution is sufficient e.g., for sources of image data or for visualisation workstations that are used by a single user. Authenticated access is certainly a logical alternative that would allow for duties in other hospitals, mobile worksites, home offices of physicians, and so on.

We solved this problem using an IPSec tunnel where a private IP address is assigned to IPSec clients based on their authentication. Each user of a shared workstation will then communicate with the PACS server via his or her own IPSec tunnel with a unique IP address. Initially, we considered the following two variants:

We finally decided to use PKI with users' credentials stored on USB keys.

In the role of the IPSec server, we used a pair of Cisco 3845 routers with HW-accelerated encryption. Cisco PIX series is not suitable as it only allows to assign addresses from a pool shared by all IPSec clients, whereas we need to assign a private IP address to each IPSec client based on his or her authentication. Hence, the only options were either a VPN concentrator of the Cisco VPN 3000 series or a generic Cisco router with a sufficient encryption performance. After considering economic parameters, we chose Cisco 3845, as the VPN 3000 concentrator is in the same price range but its performance is only one third of the former.

A Certification Authority and a pair of publication servers were established at Masaryk University for serving public PKI keys of all users. Initially, this Certification Authority will be run by Masaryk University but, depending on the number of users, other more effective variants may be considered in the future.

On the client side, one can use either the IPSec client of the Cisco VPN 3000 series (which requires no license fees) or a native IPSec client for the particular operating system. We used USB keys developed by Aladdin Knowledge Systems, Inc. for storing private PKI keys. Compatibility of this device with Cisco equipment was already verified. For this project, we obtained the minimum available order quantity, i.e., 25 pieces of USB keys and corresponding SW licenses. Additional equipment for future users will be funded from other resources.

The components of the proposed solution are installed, for safety reasons, in two sites of the Masaryk University in Brno that are far away from each other and interconnected via a high-speed network. The primary locality is the Institute of Computer Science of Masaryk University (ICS), while the secondary locality is the building of the Medical Faculty of Masaryk University.

In summary, we achieved the following goals:

13.4.2   Availability of the Distributed Medical Image Information in Case of a Malfunction in the Primary Transfer Routes

We evaluated the availability of various backup connections for remote hospitals connected via public data network. Backup of the primary data connection for these hospitals can be realised by using the one of following data circuits:

  1. A fixed dual connection of the hospital to the public data network. This solution has two major drawbacks:
    • It does not address a potential failure of Internet connectivity at the Institute of Computer Science. This problem is not critical, as that connectivity is sufficiently robust.
    • It is very expensive. The hospital should have connectivity to two different operators or at least two different PoPs of a single operator. The latter variant may be less reliable depending on the reliability and redundancy of that operator's network.

    In both cases, two independent ISP data circuits must be leased.

  2. A public dial-up data circuit to another operator. Many operators offer dial-up connections to their public telecommunication network free of charge. Such a connection, however, has insufficient transfer capacity.
  3. A dial-up data circuit "Hospital-ICS". This seems to be the only economically feasible solution with a sufficient transfer capacity. We plan to use the PPP Multi-Link protocol over the dial-up link. Using this protocol, it is theoretically possible to couple any number of transmission channels of lower capacity. The PPP Multi-Link protocol has high requirements on processor performance in the terminal unit. Currently we are looking for a device with a competitive price and sufficient CPU performance.

13.4.3   International Acknowledgement

MeDiMed represented Czech Republic at the eHealth 2005 conference in Tromso (Norway) as part of a special exhibition of successful projects, and at eHealth - Impact Case Studies 2005 in Tunis. This project was chosen and recommended by the Ministry of Informatics of the Czech Republic.

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