Dan, sounds like your conversation with World Heart folks was informative. But, some of your conclusions seem heavily influenced by your investment in WHRT. This is understandable, I would feel the same way.
Some points to consider.
1) Granted, the first targeted market for most VAD's is bridge to transplant, hopefully followed by bridge-to-recovery (permanent implant). This is a logical sequence. I cannot imagine the Heart Saver would not be used as a bridge-to-transplant first. Anything else would be foolish and over-confident. It would be like trying to run a marathon before you could walk. Jarvik tried this with the Jarvik-7. The results were less than inspiring. Whoever dominates the bridge-to-transplant market will have a huge advantage in the permanent implant market. This assumes the device is capable of doing both. Clinical data is showing that the DeBakey VAD has a high probability of achieving this.
2) Cell damage and clotting are no more of an issue with the DeBakey VAD than a pulsatile pump. Cell damage levels for the DeBakey VAD are lower than some people even believe. Clotting is proving to be less of an issue with the DeBakey VAD than with pulsatile pumps. It's all in the design. Blood gets in and out of an axial pump so much faster than a pulsatile pump. Residence time seems to be an important factor.
3) As for changing flowrate in response to physical exertion, we're not talking about taking a bedridden person and turning them into an Olympic athlete. Adding an additional 5 liters/minute will allow the patient to do all but the most strenuous tasks. When someone is able to go from complete lethargy to active walking, traveling, and normal social activities, it's a huge improvement in their quality of life.
4)Organ damage from a continuous flow vs. pulse? Don't know much about that one. I do know if the patient has a pulse at all, the DeBakey VAD will follow it and in fact amplify the pulse. Will it do this as strongly as a pulsatile pump? Certainly not. Now we're talking about degrees of pulsatility. What's sufficient for long term organ health. (140/60,120/80, etc...) Keep in mind that the speed of an extremely lightweight impeller can be changed rapidly. You don't need much of speed change to make a pulse. It's easily done. Also, it's well known that after a VAD is implanted, the patient's own heart improves, sometimes dramatically. This would result in improving pulsatility over the long term. This is not conjecture, but actual proven fact.
Add in all the features of a tiny, lightweight, low power, reliable pump and the competitive advantage gets pretty compelling.
World Heart must view the DeBakey VAD as a competitor. It could severely reduce their ability to raise capital or worse, put them in the "also ran" category.
Having said that, I'm impressed by your level of research for a non-engineer/medical type person as you say. It shows a great deal of thoroughness. Best of luck with your investment.
Regards,
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