A PC-based on-line system for physiological in vivo and in vitro experiments.

A PC-based system for data acquisition, control of experiments and analysis of physiological signals has been developed. The system has a flexibility that makes it useful for many different types of study, e.g. hemodynamics, electrophysiology and in vitro studies of organ contractile functions. The experimental set-up is specified in a number of tables, which can be modified with a table editor. The specifications can be stored in file and used for other experiments with an identical experimental set-up. The recording of data can be done either intermittently or continuously, and the intermittent recordings are initiated automatically at predefined times, or manually. With a tape recorder utility, data can be recorded during an experiment and analyzed at a later time. The signal analysis module has a high degree of flexibility, achieved by parameters defining preprocessing, heartbeat detection, heartbeat selection and analysis. Data is presented on the display in three types of window, showing phasic signals, derived parameters in trend graphs and derived parameters in numerical form. Data is saved on disk in two types of file: sampled raw data or derived parameters (ASCII file). An Ethernet-based network is used to send data to a VAX cluster, where it is further processed in RS/1 or the BIOLAB analysis program. The source code has been written in Ada, and the compiler generated a 32-bit code, which facilitated the development of a large program with large data buffers.