A new hydraulic heart assist device.

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Medical Technology

Background:

• Heart failure necessitates advanced circulatory support systems.
• Existing ventricular assist devices face challenges in efficiency and integration.
• Development of a novel hydraulic biventricular assist device (HBVAD) is crucial for improved patient outcomes.

Purpose of the Study:

• To develop and evaluate a new lightweight magnetic drive for a hydraulic biventricular assist device (HBVAD).
• To assess the haemodynamic efficiency and interaction of the HBVAD in vivo.
• To investigate the HBVAD's performance under various cardiac conditions, including simulated heart disease.

Main Methods:

• Construction of a novel lightweight magnet with a permanent magnetic armature and integrated miniature optically incremental position sensor.
• Mock circulation tests to evaluate drive stability and preload pressure sensitivity.
• In vivo experiments in calves to assess haemodynamic efficiency on beating and fibrillating hearts, and inter-device vascular interaction.
• Pharmacological interventions (verapamil, adrenaline) to model heart disease and test preload sensitivity.

Main Results:

• The HBVAD drive demonstrated stability and sensitivity to preload pressure in mock circulation tests.
• In vivo experiments confirmed the HBVAD's ability to maintain circulation and unload the natural heart.
• Independent control of left and right drives showed significant vascular interaction.
• The device responded to preload variations consistent with Starling's law, functioning with both beating and fibrillating hearts.

Conclusions:

• The developed HBVAD drive is stable, efficient, and capable of maintaining circulation.
• The HBVAD effectively unloads the native heart and exhibits predictable responses to preload changes.
• This hydraulic biventricular assist device shows promise for managing complex cardiac conditions.