EVAHEART LVAS Components
The EVAHEART Blood Pump
The EVAHEART System uses a centrifugal blood pump to generate blood flow and pressure in a patient with compromised left ventricular function.
The pump consists of an open vaned impeller positioned within the blood pump chamber, mounted on a shaft, and driven by a motor. A hydrodynamic bearing provides lubrication and support to the rotating impeller shaft. The pump is connected to the Controller by a percutaneous driveline.
The speed of the pump can be adjusted to generate flows as much as 14 liters per minute, depending on the patient’s dynamic state. For example, when the impeller is rotating at 2200 rpm, the System can produce a flow rate of 8 lpm with a pressure head (the pressure difference between pump inlet and outlet) of approximately 90 mmHg.
To reduce the risk of thrombosis, blood-contacting surfaces of the pump housing, the impeller, and both inner and outer surfaces of the Cannula are coated with MPC, a commercially developed coating by NOF Corporation of Japan.
 |
 |
Inflow Cannula and Outflow Graft
The EVAHEART Blood Pump is connected to the patient via the Inflow Cannula and the Outflow Graft. The 16 mm diameter Inflow Cannula is inserted into the apex of the left ventricle and affixed to the surface via a cuff. The pump draws blood from the left ventricle through the Inflow Cannula, and then propels it into the Outflow Graft. The distal end of the 16 mm diameter Outflow Graft is anastomosed to the ascending aorta.
Controller
The Controller provides power and control for the Blood Pump via the pump’s percutaneous driveline. The Controller display panel and audible alarms serve as the user interface to the LVAS. Specifically, the Controller displays pump speed (rpm) and power (watts), available power sources, battery charge level, and alarm codes for the Controller, Blood Pump, and CSU. The Controller is placed in a Carrying Bag during normal use.
CSU
The CSU circulates sterile water (CS fluid) to and from the Blood Pump. As the CS fluid passes through the pump it forms the lubricating film in the pump’s hydrodynamic bearing. This fluid then exits the pump and returns to the CSU where it passes through an ultrafiltration filter before it cycles through the bearing again.
CS fluid is transported to and from the Blood Pump via two tubes in the pump driveline. A mechanical seal, with a gap of 0.2 µm separates CS fluid in the hydrodynamic bearing from the pump’s blood chamber.
Power Sources
An AC/DC Adapter, 2 External Batteries and an internal Emergency Battery are used to power the EVAHEART LVAS.
The AC/DC Adapter can be plugged into any conventional grounded home outlet (100 to 125 VAC, 50/60 Hz). When power from the AC/DC Adapter is detected by the Controller, it is used preferentially to power the LVAS.
When the patient has no access to an AC power supply, the EVAHEART LVAS can be powered using rechargeable lithium ion batteries. External Batteries are charged by a separate dedicated Battery Charger and two charged batteries, in addition to the Emergency Battery, should be connected to the Controller at all times. The Controller displays the charge level(s) of all attached batteries.
The Emergency Battery serves as a backup if all other power supplies (External Batteries or AC/DC Adapter) are unavailable. The Emergency Battery is automatically charged when the Controller is connected to an AC/DC power source.
 |
 |
 |
Emergency Controller
The Emergency Controller is designed to be used – in very rare situations – as a back-up to the Controller if it fails.
When External Batteries are attached, the Emergency Controller can provide power to the Blood Pump until medical personnel can replace or repair the Controller.