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The EVAHEART Left Ventricular Assist System is composed of implantable and external components.
The implantable components are a Blood Pump,
an Inflow Cannula, and an Outflow Graft. A pump cable or driveline
passes percutaneously through the patient’s skin and connects the Blood Pump to the Controller.
The external components are the Controller with
CS System, power
sources, Emergency Controller, Outer Belt, External Monitor, and Battery Charger.
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Implantable components
Blood Pump
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The primary component of the EVAHEART System is the Blood Pump. The 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 impeller positioned within the blood pump chamber, mounted on a shaft,
and driven by a motor. The Pump is connected to the Controller by a percutaneous driveline.
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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.
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Inflow Cannula and Outflow Graft
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The EVAHEART Blood Pump is connected to the patient via the Inflow Cannula and the
Outflow Graft.
The Inflow Cannula is inserted into the apex of the left ventricle, affixed to the surface via
a sewing cuff, and then connected to the Pump.
The Outflow Graft, connected to the Pump, is then anastomosed to the ascending aorta.
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External Components
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Controller
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The Controller contains the electronic components and power to control the Blood Pump
and the CS System that maintains the bearing and seals. The Controller is connected
directly to the implanted Blood Pump by a driveline. A Controller is placed in a Carrying Bag
during normal usage. The Controller, with its displays and alarms, is the user interface
to the Blood Pump.
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The Controller displays pump speed (rpm) and pump power (watts), as well as battery status
and alarms for the Controller, Pump, and CS System Unit (CSU).
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CS System
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The CSU is the primary component of the CS System, and it consists of a
reservoir, a diaphragm pump, a filter and two pressure sensors.
The CS System circulates sterile water to the pump seal/bearing and back through the Controller.
In the event that blood gets past the seal, the CS fluid will carry it away. The fluid is then
filtered to continuously supply clean sterile water to the seal and bearing. Changes in the CS
Lines' pressures can indicate abnormalities in the CS System.
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Overview of Blood Pump and CS System
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Power Sources and AC/DC Adapter
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To power the EVAHEART LVAS safely, power sources (external batteries and an internal emergency
battery) and an AC/DC Adapter are provided.
The EVAHEART LVAS uses rechargeable lithium ion batteries; two batteries can power the system for
8 to 10 hours. A separate dedicated Battery Charger is used to charge the batteries.
The batteries are used when the patient has no access to an AC power supply. It is recommended
to keep the two batteries connected to the Controller at all times. The remaining power
left in the batteries is shown on the Controller.
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The AC/DC adapter can be plugged into any conventional grounded home outlet (100 to 125 VAC, 50/60 Hz).
When voltage from the AC/DC Adapter is detected, it is used preferentially.
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The emergency battery supplies power to the system in emergency situations, such as when
there are no outside power sources. The emergency battery is automatically
charged when connected to an AC/DC power source.
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Emergency Controller
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The Emergency Controller is designed to be used - in very rare situations - as a back-up to
the Controller if it fails.
The Emergency Controller, with batteries attached, can provide power to the Blood Pump until
medical personnel can replace or repair the Controller.
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