A continuous available (CA) server for medical imaging applications.

RATIONALE AND OBJECTIVES The trend of medical imaging research and application is toward large database management and manipulation, which requires a robust image server to receive image data from sources and to deliver them to users reliably and in a timely fashion. This article describes the design, implementation, and clinical applications of a continuous available (CA) image server for these purposes. MATERIALS AND METHODS The design of the CA image server is based on the concept of a triple modular redundancy server with three redundant server modules. Coupled with a majority voting mechanism in the three modules and failover software, the triple modular redundancy server takes care of all single points of failure hardware components in the CA image server automatically to achieve fault tolerance. Methods and procedures of evaluating the fault tolerance system reliability caused by network connectivity, motherboard, and disk storage failures are described. RESULTS Thorough experimental results in laboratory and clinical environments verify that the image server achieves 99.999% hardware up time (or 5 minutes/year down time), satisfying the industrial terminology of hardware continuous availability. Performance of failover of the CA image server is automatically tabulated during these procedures. CONCLUSION Applications of CA image server are extensive. Two examples are given including Picture Archiving and Communication System, and off-site back-up archive using the Application Service Provider model. As designed, the CA image server is portable, scalable, affordable, easy to install, and requires no human intervention during failover and system recovery.

[1]  Avelino Francisco Zorzo,et al.  Rigorous Development of an Embedded Fault-Tolerant System Based on Coordinated Atomic Actions , 2002, IEEE Trans. Computers.

[2]  Greg Mogel,et al.  Informatics in radiology (infoRAD): A complete continuous-availability PACS archive server. , 2004, Radiographics : a review publication of the Radiological Society of North America, Inc.

[3]  Bor-Chin Chang,et al.  Design of fault-tolerant systems for actuator failures in nonlinear systems , 2002, Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301).

[4]  Michel Banâtre,et al.  Lessons from FTM: An Experiment in Design and Implementation of a Low-Cost Fault-Tolerant System , 1996, IEEE Trans. Reliab..

[5]  Algirdas Avizienis,et al.  Toward Systematic Design of Fault-Tolerant Systems , 1997, Computer.

[6]  Marcello R. Napolitano,et al.  Fault detectability analysis for requirements validation of fault tolerant systems , 1999, Proceedings 4th IEEE International Symposium on High-Assurance Systems Engineering.

[7]  Jean-Charles Fabre,et al.  A Metaobject Architecture for Fault-Tolerant Distributed Systems: The FRIENDS Approach , 1998, IEEE Trans. Computers.

[8]  Karama Kanoun,et al.  Fault-tolerant system dependability-explicit modeling of hardware and software component-interactions , 2000, IEEE Trans. Reliab..

[9]  H. K. Huang,et al.  Fault-tolerant PACS server , 2002, SPIE Medical Imaging.

[10]  Jr Gerald D. Dodd.  Jack Edeiken, MD , 2002 .

[11]  Fei Cao,et al.  Clinical experiences with an ASP model backup archive for PACS images , 2003, SPIE Medical Imaging.

[12]  A. Agrawal,et al.  Fault-tolerant systems design-estimating cache contents and usage , 2002, Proceedings, IEEE Aerospace Conference.

[13]  Juan A. Carrasco.  Computationally Efficient and Numerically Stable Reliability Bounds for Repairable Fault-Tolerant Systems , 2002, IEEE Trans. Computers.

[14]  Fei Cao,et al.  Fault-tolerant PACS server design , 2001, SPIE Medical Imaging.

[15]  H. K. Huang,et al.  Fault-tolerant back-up archive using an ASP model for disaster recovery , 2002, SPIE Medical Imaging.