First experiences with the modelling and simulation package MIRACLES applied to a picture archiving and communication system (PACS) in a clinical environment.

Since the construction of picture archiving and communication systems (PACS) appears to be extremely difficult, computer modelling and simulation are used as decision support tools. The package MIRACLES (Medical Image Representation, Archiving and Communication Learned from Extensive Simulation) has been developed at BAZIS in order to support the construction of simulation models of image information systems. This article discusses the application of MIRACLES to a prototypical PACS as being installed in a clinical environment. Attention is focussed to the required system analysis and difficulties which arose during the construction of the simulation model. The emphasis is on the presentation of the results of the simulation study, which show that simulation can be fruitfully used to predict, to analyse and to assist in solving performance problems. The simulation study confirmed assumptions and suppositions concerning both the system performance itself and strategies to improve the performance. The study also resulted in a number of concrete recommendations which might be useful for the set-up of the prototypical PACS.

Prediction and analysis of PACS performance with the simulation tool MIRACLES.

Since the construction of image information systems appears to be extremely difficult in practice, BAZIS has decided to use computer modelling and simulation as decision support tools. In order to support the construction of simulation models, the simulation package and modelling environment MIRACLES (Medical Image Representation, Archiving and Communication Learned from Extensive Simulation) has been developed by BAZIS. This paper describes modelling and simulation techniques in general, as well as the benefits of simulation within the scope of designing Picture Archiving and Communication Systems (PACS). In order to illustrate the theory, results of a concrete yet simple PACS, which has been simulated with MIRACLES, will be described and discussed.

Top-down design of a picture archiving and communications system (PACS) by means of simulation.

The development of picture archiving and communications systems (PACS) for medical applications can be regarded as a challenging field in medical informatics. Since 1982, several projects have been started into this direction worldwide. The Dutch IMAGIS (Image Information System) project, started in 1984, is one of them. Within this project, a top-down design strategy is chosen, with the following first steps: (1) A thorough information analysis for a Radiology Department, in which both qualitative and quantitative aspects are included. Such an analysis can be used to estimate the workload on a future PACS system. (2) The construction of a flexible performance prediction tool, based on discrete even simulation. Such a tool can be used to predict the performance of a certain computer system configuration under a certain workload. Based on the information analysis, and using the performance prediction tool, a PACS system is drafted for the thorax section of the Diagnostic Radiology Department of the Leiden University Hospital. In this first design attempt, the assumption was made that current working procedures concerning images will be maintained as much as possible.