Computer control of a modified Langendorff perfusion apparatus for organ preservation using cryoprotective agents.

The construction of an isolated rat heart cryopreservation apparatus which is interfaced to a process-control computer is described. The flexibility of the equipment is demonstrated by the running of simultaneous dual sets of experiments under multiple and variable conditions. The computer-control program allows interactive calibration of the instruments, accurate control of variables and modification of parameters during the experiments. By controlling the speed of the perfusate's peristaltic pump, perfusion pressure was not allowed to exceed a present level. Experiments are reported which allow the storage of hearts at -22 degrees C with the aid of the cryoprotective agents, ethylene glycol.