Computerized Medical Devices: Trends, Problems, and Safety

Virtually all of the medical devices utilizing electronics will contain a micro or minicomputer by 1990. These devices accounted for $7 billion in U.S. sales in 1984. Their capabilities can provide the means for new or greatly improved medical procedures, and ensure greater patient safety. However, these benefits can easily be compromised if ``computer safety' is not practiced in the design, manufacturing, testing and clinical use of these devices. Along with a trend to wider usage, the number of recalls of medical devices due to computer-related problems has approximately doubled in the last five years. ``Computer-caused' problems are often not recognized or reported as such, resulting in an underestimation of the prevalence of this type of problem. Our study of technical factors causing problems in computerized devices revealed that software quality assurance (SQA), the quality of the ac power, and electromagnetic interference are primary factors. Selected design and QA techniques that are well-known in military-aerospace industries can be used to prevent the most prevalent problems occurring in computerized medical devices, without significantly affecting overall device manufacturing costs.     

Training astronauts using three-dimensional visualisations of the International Space Station

Recent advances in personal computer technology have led to the development of relatively low-cost software to generate high-resolution three-dimensional images. The capability both to rotate and zoom in on these images superposed on appropriate background images enables high-quality movies to be created. These developments have been used to produce realistic simulations of the International Space Station on CD-ROM. This product is described and its potentialities demonstrated. With successive launches, the ISS is gradually built up, and visualised over a rotating Earth against the star background. It is anticipated that this product's capability will be useful when training astronauts to carry out EVAs around the ISS. Simulations inside the ISS are also very realistic. These should prove invaluable when familiarising the ISS crew with their future workplace and home. Operating procedures can be taught and perfected. "What if" scenario models can be explored and this facility should be useful when training the crew to deal with emergency situations which might arise. This CD-ROM product will also be used to make the general public more aware of, and hence enthusiastic about, the International Space Station programme.     

Formal verification and legacy redesign

Sustaining weapons system hardware and software represents a significant and ever-increasing portion of total system cost. Hardware components are becoming obsolete much sooner while weapons system lifetimes are increasing, We must identify more cost-effective solutions to engineering and reengineering these subsystems. Verifying and validating weapons systems are two of the most costly parts of either engineering process. Traditionally, hardware validation and verification is done by simulation and testing, In the past few years, math- and logic-based formal methods tools have begun to scale up to and be applied successfully to real-world problems. Incorporating formal verification methods into engineering and reengineering processes will cost-effectively and significantly improve the level of trust and the quality of our weapons systems. Formal methods are especially well suited for redesigning current weapon systems which have become unsupportable due to component obsolescence because they help minimize the astronomical costs of rigorously reverifying the reengineered components. We believe that formal methods are an important tool for effective engineering of future weapon systems