A cardio-stimulator of the 23rd century
A cardio-stimulator aboard DS9
A cardio-stimulator aboard Voyager
The cardio-cstimulator was a Federation medical device used for cardio-stimulation: to restart a stopped heart.
A cardiostimulator was among the medical equipment, E'Lis received from Doctor Phlox in 2152 to treat the injuries in their mining colony. Phlox noted that he was unaware that processing deuterium was such a dangerous business. (ENT: "Marauders")
In 2154, Doctor Phlox attempted to use a cardio-stimulator to save Major Hayes. Unfortunately, the major's injuries were too extensive, and he died. (ENT: "Countdown")
In 2268, Doctor Leonard McCoy used a portable version of the device aboard the USS Enterprise during an operation on Ambassador Sarek, after the power to sickbay had failed and the operating table's own cardio-stimulator had ceased functioning. (TOS: "Journey to Babel")
In 2371, The Doctor used a cardio-stimulator to revive Commander Chakotay after his bio-neural energy was displaced by the Komar. (VOY: "Cathexis")
In 2378, Tom Paris used a cardio-stimulator to cajole the heart of Brin's son to life. Although the initial charge of three millijoules was unsuccessful, the second charge set at five millijoules was successful. (VOY: "Friendship One")
Contemporary cardiac defibrillators can be viewed as forerunners of this device.