technology differentiation

The key to Ventracor succeeding is their being able to claim they have developed a different product to their competitors.

The serious issues they claim to have solved is clotting and strokes and device longevity due to the wearing out of parts. This is because of the non-pulsatile nature of the pump and the liquid cushion which replaces bearings. (refer New Scientist article).

I am not clear how well MicroMed (or the other hopefuls) have progressed in this regard. The diagram on their website looks like a plain cylinder with an impeller (driven by a DC motor).

The trial results are key. VCR have performed very, very well in the pilot, given the condition of the patients who qualified for the implant. They are likely to do so much better with healthier candidates, and their experiences will drive the success or otherwise of VCR.

VCR needs to have many results like the one quoted on their website (and I think they have that potential) .....

"I can walk with my wife when she goes shopping. Before I wasn't fit enough. We now go out for dinner, which I wouldn't have been able to do. I was able to go to my grandchild's graduation, which I would probably have missed. "It's changed my life a lot. You ought to see the smile on my wife's face." July 2004


New Scientist - Simpler pump boosts failing hearts - 29 July 2004

Most LVADs attempt to mimic the way the heart works, but their complicated design makes them prone to failure, and they have a tendency to make blood pool and clot, leading to strokes. That means LVADs are usually only used as a last resort for patients waiting for heart transplants.

What makes the VentrAssist different is that it only has one moving part, a spinning impeller that drives a continuous stream of blood. That means the pulse is replaced by a gentle whirling noise that patients describe as similar to the sound of a washing machine. More importantly, the device prevents blood from stagnating, reducing the risk of clotting.

Six copper coils within the device's titanium walls generate magnetic fields that make the magnet-cored impeller blades spin (see graphic). The blades push blood out to the body while forming a high-pressure, liquid cushion that levitates the impeller and holds it steady.

Most other attempts to use continuous rotary pumps in LVADs have relied on bearings to hold the impeller blades in place, making them susceptible to wear and failure.


Ventracor website product description

VentrAssist™ has only one moving part – a hydrodynamically suspended impeller. It has been designed to have no wearing parts or cause blood damage.


MicroMed website product description

The inducer/impeller is the only moving part of the pump. It has six blades with eight magnets hermetically sealed in each blade. The inducer/impeller spins at 7,500-12,500 RPM and is capable of generating flow in excess of 10 liters per minute.

The components are fully enclosed in a titanium flow tube that has been hermetically sealed. The pump is driven by a brushless, direct current (DC) motor stator that is contained in the stator housing.

The pump is attached to a titanium inlet cannula that is placed into the left ventricle. A graft is connected to the pump outlet and anastomosed to the aorta.

Weighing less than four ounces, the device is silent and is approximately 1/10 the size of other pulsatile products on the market. The MicroMed DeBakey VAD® is designed to be a lower-cost, less invasive alternative to the commercially available, larger ventricular assist devices (VADs).