A versatile cardiac electrical stimulator for clinical and experimental use.

A cardiac electrical stimulator developed for clinical and laboratory applications is described. The stimulator has 5 separate generators and 4 output channels. The generator settings are defined by the operator using a special keyboard, with the same structure as a television screen on which all the parameters are displayed. A number of user-specified settings can be stored in the apparatus and are available within seconds. Several programming modes provide a simple way to determine stimulation thresholds and/or refractory periods. Hardware and software security checks prevent dangerous stimulation in case of malfunction or erroneous settings. The stimulator control unit is digitally connected to constant current output stages located near the stimulation site. The stimulator functions are performed by programmable hardware controlled by a microcomputer dedicated exclusively to the presentation and input of stimulator settings. The application of a simple (personal) microcomputer leads to a favorable price/performance ratio.