Technology background

Sun Medical Technology Research Corporation, Suwa City, in the Nagano Prefecture of Japan ("SMT": www.evaheart.co.jp) is a technology holder and developed EVAHEART® LVAS in conjunction with Prof. Kenji Yamazaki, Professor & former Chairman at Tokyo Women’s Medical University, Department of Cardiothoracic Surgery. Dr. Yamazaki is an inventor of the EVAHEART® concept in collaboration with several universities including Wasada University, Tohoku University, Tokyo Women’s Medical University and the University of Pittsburgh. Arriving at the first clinical design in 2002, the Company completed final verification testing and, in 2005, initiated a clinical trial in Japan. The first-in-human use of the EVAHEART® LVAS occurred at Tokyo Women’s Medical University on May 7, 2005. The Company completed the clinical trial consisting of 18 patients in 2008 and final regulatory approval was granted by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) in Japan. SMT will supply the EVAHEART® LVAS and related components to EVI for use in North America, Europe, and other sales territories.

 Configuration of Evaheart Ventricular Assist Device System

Configuration of Evaheart Ventricular Assist Device System

Hydraulically levitated centrifugal pump 

 Open-vane type centrifugal pump

Open-vane type centrifugal pump

 Cross sectional schematic of the EVAHEART pump head

Cross sectional schematic of the EVAHEART pump head

Evaheart implemented a proprietary cooling mechanical seal system for an open vane impeller. The spinning impeller is levitated with an ultra thin layer of circulating sterile water, which in turn lubricates and cools down the temperature around the shaft.

The speed of the pump can be adjusted to generate high peak flows up to 14 liters, depending on the patient’s dynamic state. When the impeller is rotating at 2200 rpm, the Evaheart can produce a flow rate of 8 L/min 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.

 

Flexible e-PTFE 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.

                            e-PTFE graft with polymer spiral reinforcement

                           e-PTFE graft with polymer spiral reinforcement

Double cuff Tip-less inflow cannula

The new double cuff tip-less inflow cannula is designed with significantly improved anatomical fitting in mind. This technology enhances tissue in-growth and may contribute to decrease post LVAD stroke.

 The flush inflow ostium in the left ventricle, low profile inflow design, rotational apex suture cuff are designed to be forgiving on possible inflow cannula malposition and to minimize the risk of wedge thrombus.

The flush inflow ostium in the left ventricle, low profile inflow design, rotational apex suture cuff are designed to be forgiving on possible inflow cannula malposition and to minimize the risk of wedge thrombus.

Controller and Cool Seal Unit (CSU)

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.

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.

 Left: C02 External Controller Unit, Right: Cool Seal Unit (CSU)

Left: C02 External Controller Unit, Right: Cool Seal Unit (CSU)