@ David Bell
Perhaps the unit could be fitted with a small speaker in order to produce artifical heart sounds, similar to electric cars being fitted with speaker to play fake engine sounds.
Seriously though, this is good work, but with heart disease being one of the biggest causes of death, the population is going to explode. I wonder how much one of these will extend the average lifespan.
Also, I don't think the circulatory system will have any problems dealing with this as the overall pressure will be lower. I do wonder whether the constant flow will have any weird effects on the body though, perhaps just because some systems work best with a pulsed blood supply. I'm no biology expert though so I have no idea whether any such systems exist, was just a curious thought :)
The unit could react to demand by monitoring the difference in oxygen levels leaving and entering the unit. I'm not up to date with my medical technology so I don't know whether something like that is possible on this scale. Anyone else know anything about this? I'm quite interested in learning more.