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To detect complex ventricular arrhythmias in different stages of chronic chagasic cardiopathy, the results of exercise testing to 24 hours Holter monitoring have been compared. We evaluated a group of 71 patients, half women, aged 51+/-10.3, with no others associated diseases. These patients were separated in 4 groups according to degree of cardiac involvement. Statistical data can be found elsewhere in the study. In group IA, Holter monitoring detected 4.3% of complex ventricular arrhythmias, group IB 25%, group II 55% and group III 90%. We found no difference between Holter and exercise testing in the detection of complex ventricular arrhythmias in groups II and III (p = ns). In groups IA and IB we found 100% concordance, concerning the no detection of complex ventricular arrhythmias by exercise testing seen by two independent examiners. In group II there was a 70% concordance (kappa = 0.368, p = 0.003) and 90% in group III (kappa = 0.78, p = 0.002). Different results were found, concerning the presence of complex ventricular arrhythmias, among patients in the initial and advanced stages of chronic chagasic cardiopathy. In groups II and III we found no difference between the two methods in the detection of complex ventricular arrhythmias. It seems reasonable to recommend either Holter on exercise testing in groups IA and IB if progression of disease is noticed.

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This paper describes the control system design for the Marlim three phase subsea separation system (SSAO) and how the standard subsea control system has been adapted for the new requirements for automated control. This is the most advanced subsea process system to date with several "first ever" applications of separation equipment subsea: harp, pipeseparator, desanders and hydrocyclones. The SSAO has a total of 7 control loops and a number of complex automatic sequences. Further, the paper addresses how dynamic simulation analysis has been used to validate the process control strategy and improve the operational procedures designed during the basic engineering phase. Control and operation of the SSAO has proved to be very challenging for several reasons:• There are strong interactions between different process components • The system dynamics are stiff due to small liquid hold-ups and low GOR in the system • The pressure drops of inline cyclonic equipment need to be balanced to ensure optimal performance • Constraints in valve opening/closing speed and the importance of limiting the number of valve movements put restrictions on controller performance • Instrumentation is limited compared to topside facilities The content described above contain several new aspects compared to a traditional subsea control system and this paper will describe system considerations with regards to implemented process control and also the importance of using dynamic simulations as a design tool.

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