Telemedicine and Its New Trends Xiaomei Yu Biomedical and Multimedia Information Technology (BMIT) Group, Basser Dept. of Computer Science, University of Sydney, NSW 2006, Australia

Telemedicine and Its New Trends Xiaomei Yu Introduction Current Applications Background A Prototype of Telemedicine Conclusions Biomedical and Multimedia Information Technology (BMIT) Group, Basser Dept. of Computer Science, University of Sydney, NSW 2006, Australia

Introduction Abstract--With the advancement of information and communications technology, how to use such technology to provide more efficient and convenient medical services becomes a very important and unavoidable issue. Telemedicine is the use of electronic information and communications technologies to provide and support health care when distance separates the participants. It has been used since 1920s. In the 1970s and 1980s, there are some large-scale demonstrations in telemedicine involving satellites, and telemedicine experiments focused on the transmission of medical images using television. WWW-based, ATM or ISDN network telemedicine applications are widely developed in the 1990s, most trials have experimented with the use of videoconferencing for remote consultation. In this paper, we first give a brief review of the history of telemedicine, then summarize the current applications, and provide a new prototype of telemedicine system. Generally speaking, the techniques of telemedicine system include: (1) image acquisition, (2) storage and retrieval, (3)telecommunications, (4) display and interpretation. (5) remote control.

Introduction In the 1970s and 1980s, the main techniques are: 1) network linked by telephone, cable television, microwave and satellite; 2) transmission of data, freeze-frame video, audio, facsimili, and medical information such as stethoscpic, endoscopic, microscopic, X-ray, electrocardiogram (EKG), and electro-encephalogram (EEG) brain-wave information. Black-white two-way interactive television was mainly used. Remote camera control, slow scan television and video tapes were used as well. In 1990s, the applications of telemedicine are more cost-effective, wide spread and facilitated. Asynchronous Transfer Mode (ATM), Integrated Services Digital Network (ISDN) and WWW-based network telemedicine applications are widely developed. Most trials have experimented with the use of videoconferencing for remote consultation.

Current Applications Internet, ATM or ISDN network Internet is the global internet based on the Internet (TCP/IP) architecture, connecting millions of hosts worldwide. Because it is wide spread and cost efficient (just as telephone call), it is getting popular recently. Example: Department of Radiological Sciences, Medical Center in UCLA developed a WWW telemedicine system using Java and Common Gateway Interface (CGI). Center of Medical Informatics, University Hospital of Geneva, Swizerland developed a tool for in-house access to PACS images and related data through WWW. They used ESQL for PACS database retrieval and resulted image can be stored by FTP.

Current Applications Internet, ATM or ISDN network ISDN is a digital communication service offered by telephone carriers and standardized by ITU-T. It combines voice connection and digital data services in a signal physical medium. The bandwidth range covers Kbps. Primary rate can be up to 1.54Mbps. Its capacity provides the basic videoconferencing video, but with the high compression ratio involved in these systems. Examples: Univ. of Washington: test, 128, 256, 384kbps. Univ. of Pittsburgh: 128kbps. ATM is a connection-oriented network technology that uses small, fixed size packets to carry data. The bandwidth range is from 45Mb/s to 2.48Gb/s. Examples: UCSF: 155Mbps, 8.3Mbytes/s(M-M). UCLA:137Mbps, 25Mbps. The combination of ATM and ISDN: European RETAIN project, TELEMEDICINA (Spain) ( ATM 155Mbps & ISDN).

Current Applications PACS-based telemedicine *A PACS consists of image and data acquisition, storage and display subsystems integrated by various digital networks. *Digital Imaging Communications in Medical (DICOM) provides standard formats for images, a common information model, application service definitions and protocols for communications. *Significance of DICOM: solving the Interoperability including exchanging images between equipments from multiple vendors, which is a long-standing problem for implementation of PACS in hospital. *an infrastructure to facilitate the implementation of telemedicine systems. Example: UCLA, UCSF have devoted some efforts on PACS-based telemedicine. Access image data stored at the remote hospital PACS archive was as easy as access to any images stored on any of the local distributed PACS archives. The images come from another hospital or from a local archive was transparent to the user.

Current Applications Videoconferencing/Remote control Videoconferencing is a very hot topic in multimedia network currently. The goals of videoconferencing and remote control are identical: to achieve real time synchronized teleconsultation. A large number of some-scale telemedicine systems have applied videoconferencing. In Japan, a telemedicine system is developed by Center Research laboratory of Hitachi, Ltd., which sent control data (such as telepointer, drawing line, comment) to reach remote control through the 64kbps N-ISBN during the actual conference. [36] The image data is sent to each side on duplicate IS&C (image save and carry) disks (650Mbyte) by mail or courier before the conference. The telepointer could be controlled with no noticeable delay by sending only the pointer's coordinates. Another kind of remote control is applied in telesurgery, in which the surgeon works on a virtual patient while a "robot" performs the actual surgery on the human subject at a remote location. PC-based, House-based telemedicines have been developed as well.

Background Telemedicine has a long history in Australia as well. The Children's Hospital Westmeat has installed a large-scale PACS for two years which is serviced by a comprehensive database of images and reports with integration through the ethernet to a Radiology Information System (RIS) and a Hospital Information System (HIS). There are about 60 terminals in hospital. The doctor and radiologist referring patient images do not need any films at all. A teleradiology system is being designed to link with Dubbo Base Hospital by 384kbps ISDN. One of the telemedicine requirements is real time consultation of obstetrical ultrasound examination of potential high-risk pregnancies. The 384kbps bandwidth provides the real time transfer, with compressed ultrasound images (25 frames/s).

A prototype of telemedicine system A prototype of telemedicine system -----Object-oriented Teleultrasound. Advantages: the content-based retrieval and video indexing are applied in it. Some image processing techniques also are used. A WWW interface for database accessed by internet is also designed. A remote control for teleconsultation will be used as well. (tele-education and consultation off hours.) Significance: 1) the current retrieval used in telemedicine systems and PACSs is key word retrieval, which using patient ID, birthday or other item of record as word to search. However, when a doctor encounters a special case of images, he prefers find some other similar images to refer. This can not be achieved by key word retrieval. However, content-based retrieval can provide it. It can be widely used in tele-education as well. 2) In teleultrasound, a large number of ultrasound sequences images are stored on a database. For such database, efficient retrieval and management are important and potential issues. 3) To satisfy some clinical requirements such as real time boundary detection and measurements of ultrasound image at the receiver side.

A prototype of telemedicine system The contents of telemedicine system are shown as follows: 1) image acquisition: ultrasound images are directly obtained from ultrasound scanner. 2) DICOM & compression: received ultrasound sequences are converted to DICOM format, then compressed. 3) communication: any universal communication tools can be used, such as ISDN, ATM. Internet also will be applied to access database. 4) Database: content-based retrieval and video indexing. 5) Display and remote control: border detecting and parameter measuring are used. Remote control will be used as well.

Conclusions A lot of telemedicine systems have been developed and used in rural areas recently. Some life safe examples have shown the significance of telemedicine. Although the current communications and computer technologies have enough capability to support preliminary requirements of telemedicine, there are still some technical challenges. Other factors such as law, cost effectiveness, patient acceptability and physician tolerance will affect the implement of telemedicine. In the future, with the further advancement of information, communication technology and the support of governments, telemedicine systems can be implemented on any area to replace current medical model in the world. In this paper, we have given a brief review of the history of telemedicine and summarized the current application. The prototype of telemedicine system is also provided to solve some requirements of telemedicine. Further research is necessary to explore video coding and motion analysis of ultrasound.