Genetic algorithms in pseudorandom testing of medical digitalcircuits

In this paper the problem of unsatisfactory diagnostic efficiency of pseudorandom testing (PRT) technique used to detect faults of digital circuits in testing medical systems of critical importance is presented. The simulations have revealed a weakness of commonly used PRT technique that generally does not assure that all stuck at faults are detected. Thus, it is suggested that PRT technique should be supplemented with additional deterministic testing sequences to enhance fault detection. To design built-in selftesting (BIST) structures a genetic algorithm and digital system stochastic model were used. By employing the stochastic model it is possible to reduce considerably the computer simulation time required for BIST architecture design. In particular, an effect of proportional and ranking selections on the convergence of genetic algorithm in searching for a globally optimal solution, while maintaining the diversity of the population of individuals and limiting its premature stagnation.