OPTIMIZATION OF A LOW-COST TRULY PREEMPTIVE MULTITASKING PC DIAGNOSTIC WORKSTATION

The Windows 95/NT operating systems (Microsoft Corp, Redmond, WA) curr ently provide the only low-cost truly preemptive multitasking environm ent and as such become an attractive diagnostic workstation platform. The purpose of this project is to test and optimize display station gr aphical user interface (GUI) actions previously designed on the pseudo multitasking Macintosh (Apple Computer, Cupertino, CA) platform, and i mage data transmission using time slicing/dynamic prioritization assig nment capabilities of the new Windows platform. A diagnostic workstati on in the clinical environment must process two categories of events: user interaction with the GUI through keyboard/mouse input, and transm ission of incoming data files. These processes contend for central pro cessing units (CPU) time resulting in GUI ''lockout'' during image tra nsmission or delay in transmission until GUI ''quiet time.'' WinSocket s and the Transmission Control Protocol/lnternet Protocal (TCP/IP) com munication protocol software (Microsoft) are implemented using dynamic priority timeslicing to ensure that GUI delays at the time of Digital Imaging and Communications in Medicine (DICOM) file transfer do not e xceed 1/10 second. Assignment of thread priority does not translate in to an absolute fixed percentage of CPU time. Therefore, the relationsh ip between dynamic priority assignment by the processor, and the GUI a nd communication application threads will be more fully investigated t o optimize CPU resource allocation. These issues will be tested using 10 MB/sec Ethernet and 100 MB/sec fast and wide Ethernet transmission. Preliminary results of typical clinical files (10 to 30 MB) over Ethe rnet show no visually perceptible interruption of the GUI, suggesting that the new Windows PC platform may be a viable diagnostic workstatio n option. Copyright (C) 1997 by W.B. Saunders Company.