Telemedicine journal : the official journal of the American Telemedicine Association最新文献

Cooperative telemedicine environments are required for many situations such as consultations between residents and senior doctors, case correlations, and for teaching and research purposes. The mode of collaboration may vary with different situations, in terms of the synchronisation of tasks, the sharing of data and the extent of collaboration among participants. It is essential for participants to be able to remotely view and manipulate visual data (images, two-dimensional and three-dimensional graphics, animation, and video) as well as interactively run application programs that involve visual data in real-time. However, this is not possible with current network bandwidth limitations when large amount of visual data are involved. In this article, we first provide an analysis of functional requirements by participants in cooperative diagnosis in different types of situations, before discussing technical requirements, which form the basis for our system architecture design. A new approach is also presented for efficient handling of programs, which involve visual data in real time. This is achieved via the construction and transmission of small messages that encapsulate the operations in a pipelined or hierarchical fashion.

Many medical services are often not available to people living in remote areas because of the lack of medical specialists. This problem would be alleviated if a suitable environment was designed to allow physicians to collaborate and exchange ideas with centrally located medical specialists. This article describes an ongoing research project to design and implement a collaborative multimedia environment to allow medical specialists to cooperate in diagnosis. The environment will support remote database access for medical images, the retrieval of relevant medical cases to support diagnosis, and communication among participants through telepointers and image annotation by free-hand drawing.

In this article, three novel lossless image compression schemes, hybrid predictive/vector quantization lossless image coding (HPVQ), shape-adaptive differential pulse code modulation (DPCM) (SADPCM), and shape-VQ-based hybrid ADPCM/DCT (ADPCMDCT) are introduced. All are based on the lossy coder, VQ. However, VQ is used in these new schemes as a tool to improve the decorrelation efficiency of those traditional lossless predictive coders such as DPCM, adaptive DPCM (ADPCM), and multiplicative autoregressive coding (MAR). A new kind of VQ, shape-VQ, is also introduced in this article. It provides predictive coders useful information regarding the shape characters of image block. These enhance the performance of predictive coders in the context of lossless coding. Simulation results of the proposed coders applied in lossless medical image compression are presented. Some leading lossless techniques such as DPCM, hierarchical interfold (HINT), CALIC, and the standard lossless JPEG are included in the tests. Promising results show that all these three methods are good candidates for lossless medical image compression.

Telemedicine involves the integration of information, human-machine, and healthcare technologies. Because different modalities of patient care require applications running on heterogeneous computing environment, software interoperability is a major issue in telemedicine. Software agent technology provides a range of promising techniques to solve this problem. This article discusses the development of a methodology for the design of interoperable telemedicine systems (illustrated with a tele-electrocardiography application). Software interoperability between different applications can be modeled at different levels of abstraction such as physical interoperability, data-type interoperability, specification-level interoperability, and semantic interoperability. Software agents address the issue of software interoperability at semantic level. A popular object-oriented software development methodology - unified modeling language (UML) - has been used for this development. This research has demonstrated the feasibility of the development of agent-based interoperable telemedicine systems. More research is needed before widespread deployment of such systems can take place.

The objective was to evaluate digital images of the retina from a handheld fundus camera (Nidek NM-100) for suitability in telemedicine screening of diabetic retinopathy. A handheld fundus camera (Nidek) and a standard fundus camera (Zeiss) were used to photograph 49 eyes from 25 consecutive patients attending our diabetic clinic. One patient had cataracts, making it impossible to get a quality image of one of the eyes (retina). The Nidek images were digitized, compressed, and stored in a Fujix DF-10M digitizer supplied with the camera. The digital images and the photographs were presented separately in a random order to three ophthalmologists. The quality of the images was ranked as good, acceptable or unacceptable for diabetic retinopathy diagnosis. The images were also evaluated for the presence of microaneurysms, blot hemorrhages, exudates, fibrous tissue, previous photocoagulation, and new vessel formation. kappa Values were computed for agreement between the photographs and digital images. Overall agreement between the photographs and digital images was poor (kappa < 0.30). On average, only 24% of the digital images were graded as being good quality and 56% as having an acceptable quality. However, 93% of the photographs were graded as good-quality images for diagnosis. The results indicate that the digital images from the handheld fundus camera may not be suitable for diagnosis of diabetic retinopathy. The images shown on the liquid crystal display (LCD) screen of the camera were of good quality. However, the images produced by the digitizer (Fujix DF-10M) attached to the camera were not as good as the images shown on the LCD screen. A better digitizing system may produce better quality images from the Nidek camera.

Aging populations and rising health costs have created the need to care for more patients in their own homes. Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) is developing a project, Hospital Without Walls, which aims to provide continuous monitoring of patients in certain diagnostic categories. The key technology is a miniature, wearable, low-power radio that can transmit vital sign and activity information to a home computer, from which data may be sent by telephone line and the Internet to appropriate medical professionals. The initial clinical scenario for this work is monitoring of elderly patients who have presented to hospitals following repeated falls. Accelerometers built into the radio sets will monitor activity and detect and characterise falls. Simultaneous measurement of heart rate will provide information about abnormalities of cardiovascular physiology at the time of a fall. The system has been tested in laboratory conditions and is being adapted for initial clinical trials.

This article relates to a teleradiology trial undertaken in 1998-1999 at the Women's and Children's Hospital (WCH) in Adelaide, the capital of South Australia. The trial involved linking the hospital to a range of rural and remote sites in South Australia and the Northern Territory. The main aim of the project was to evaluate the advantages, limitations, benefits, and costs of a teleradiology service provided by WCH. The major finding from the study is that for a tertiary hospital providing second opinions in complex medical cases, a new form of business justification is required for teleradiology. The justification would include an emphasis on the range of high-level services that a subspecialist hospital such as the WCH can provide. The justification would also include the range of benefits to different parties, particularly the patient, and the intangible nature of many of the benefits.

The objective was to review multipoint videoconferencing in Queensland Health from July 1996 to June 1999. Most videoconferencing has been conducted using desktop systems connected by integrated systems digital network (ISDN) at 128 kbps. Data on utilization and problems were extracted from monthly reports and a survey was conducted. Multipoint videoconferencing increased steadily over the 3 years from just and handful of conferences per month to 101 conferences and 703 hours of bridge use per month. Primary uses were education and administration. Relatively few technical failures and operator errors were recorded. But by 1999, late connection and low attendance were major problems. Survey responses indicated that multipoint videoconferencing met expectations at the great majority of sites. Most respondents were satisfied with the level of administrative and technical support provided. In this large and decentralized state, multipoint videoconferencing has proven a useful and effective means of bringing healthcare workers together for a common purpose, supplementing face-to-face events and other encounters mediated by communications technology such as satellite broadcasts and audioconferences.