[A portable manual sternal compressor for cardiac massage of a patient under transportation--1. Evolution after trials and errors].

Difficulties of external cardiac massage during transportation of a patient on a litter or stretcher prompted us to develop a new portable manual sternal compressor. A seemingly good idea of sternal compression with an inflatable balloon placed between the sternum and a chest band engaged us in a long ordeal of trial and error until we retreated from this preconception. A practical sternal compressor has finally been created by applying two hydraulic pistons, one as a sternal compressor and the other as its push-pull energizer incorporated into a manual lever system. In this paper, one of the serial reports on this new device, all our errors are described lest some one in the future meet the same problems. Details of this new apparatus and the results of our experimental study and clinical application will soon follow this paper.