A system and method of increasing the pumping efficiency of an individual's heart, wherein an actual pumping efficiency is compared to an optimal pumping efficiency to determine a force assist profile. A cardiac assist device is created that will apply the force assist profile to the heart. The cardiac assist device is surgically inserted in vivo to physically affect the heart. The cardiac assist device has an outer shell and at least one inflatable membrane that passes over the ventricles of the heart, wherein the inflatable membrane is inflated and deflated in accordance with a pressure profile provided by a pneumatic pump. The outer shell embodies outer shell strain characteristics. Each inflatable membrane embodies membrane strain characteristics. The force assist profile is a function of the outer shell strain characteristics, the membrane strain characteristics, and the pressure profile.

A system and method of increasing the pumping efficiency of an individual's heart, wherein an actual pumping efficiency is compared to an optimal pumping efficiency to determine a force assist profile. A cardiac assist device is created that will apply the force assist profile to the heart. The cardiac assist device is surgically inserted in vivo to physically affect the heart. The cardiac assist device has an outer shell and at least one inflatable membrane that passes over the ventricles of the heart, wherein the inflatable membrane is inflated and deflated in accordance with a pressure profile provided by a pneumatic pump. The outer shell embodies outer shell strain characteristics. Each inflatable membrane embodies membrane strain characteristics. The force assist profile is a function of the outer shell strain characteristics, the membrane strain characteristics, and the pressure profile.