Prototype Development of an Implantable Compliance Chamber for a Total Artificial Heart

Abstract

At our institute a total artificial heart is being developed. It is directly actuated by a linear drive in between two ventricles, which comprise membranes to separate the drive and blood flow. A compliance chamber (CC) is needed to reduce pressure peaks in the ventricles and to increase the pump capacity. Therefore, the movement of the membrane is supported by applying a negative pressure to the air volume inside the drive unit. This study presents the development of the implantable CC which is connected to the drive unit of the total artificial hearts (TAH). The anatomical fit of the CC is optimized by analyzing CT data and adapting the outer shape to ensure a proper fit. The pressure peaks are reduced by the additional volume and the flexible membrane of the CC. The validation measurements of change in pressure peaks and flow are performed using the complete TAH system connected to a custom mock circulation loop. Using the CC, the pressure peaks could be damped below 5 mm Hg in the operational range. The flow output was increased by up to 14.8% on the systemic side and 18.2% on the pulmonary side. The described implantable device can be used for upcoming chronic animal trials.

Apical aortic blood pump preclinical assessment for long‐term use: Durability test and stator topology to reduce wear in the bearing system

“…This test consists of maintaining the device under similar (head pressure and flow) conditions when implanted until device failure. An AAPB prototype was connected to a mock loop circulation system for specific parameters register, and those registered parameters include: current consumption [A], stator (Tstator) and environment temperatures [ºC], and head pressure [mm Hg)]. Figure presents a scheme for the mock circulation loop system.…”

“…This test consists of maintaining the device under similar (head pressure and flow) conditions when implanted until device failure. An AAPB prototype was connected to a mock loop circulation system [4][5][6] for specific parameters register, and those registered parameters Head pressure in this system was maintained at 100 mm Hg, flow was 5 L/min. Those values represent the mean operation values for a LVAD during mechanical assistance and were considered as reference for the durability tests.…”

Downsizing of a Pulsatile Total Artificial Heart—The Effect on Hemolysis

“…An additional CC connected to the TAH is still mandatory when implanted to achieve a pneumatic decoupling of both membranes and thereby ensure a passive filling of each pump chamber during its diastole. 6 A hermetically sealed drive unit could provoke suction of the atria, higher inflow acceleration and faster closing of the mechanical heart valves. A prototype of a fully implantable CC was designed and its influence on hemolysis was investigated in comparative trials.…”

“…First studies demonstrated its proof of principle. [3][4][5][6][7][8] The new downsized ReinHeart TAH uses the same principle as already described in literature but with its implantable pump unit reduced in volume by 20% to around 390 ml and a new stroke volume of around 34 ml (compared with 41 ml of the original design). A comparison of both designs can be seen in Figure 1.…”

Artificial Organs 2017: A Year in Review

“…Schmitz et al of RWTH‐Aachen University, Aachen, Germany reported on their development of a compliance chamber (CC) for their total artificial heart (TAH). They optimized the anatomical fit of the CC by analyzing CT data and adapting the outer shape to ensure a proper fit.…”