Compliant Buckled Foam Actuators and Application in Patient-Specific Direct Cardiac Compression. Academic Article uri icon

Overview

abstract

  • We introduce the use of buckled foam for soft pneumatic actuators. A moderate amount of residual compressive strain within elastomer foam increases the applied force ∼1.4 × or stroke ∼2 × compared with actuators without residual strain. The origin of these improved characteristics is explained analytically. These actuators are applied in a direct cardiac compression (DCC) device design, a type of implanted mechanical circulatory support that avoids direct blood contact, mitigating risks of clot formation and stroke. This article describes a first step toward a pneumatically powered, patient-specific DCC design by employing elastomer foam as the mechanism for cardiac compression. To form the device, a mold of a patient's heart was obtained by 3D printing a digitized X-ray computed tomography or magnetic resonance imaging scan into a solid model. From this model, a soft, robotic foam DCC device was molded. The DCC device is compliant and uses compressed air to inflate foam chambers that in turn apply compression to the exterior of a heart. The device is demonstrated on a porcine heart and is capable of assisting heart pumping at physiologically relevant durations (∼200 ms for systole and ∼400 ms for diastole) and stroke volumes (∼70 mL). Although further development is necessary to produce a fully implantable device, the material and processing insights presented here are essential to the implementation of a foam-based, patient-specific DCC design.

publication date

  • October 26, 2017

Research

keywords

  • Heart-Assist Devices
  • Robotics

Identity

PubMed Central ID

  • PMC5804100

Scopus Document Identifier

  • 85041953577

Digital Object Identifier (DOI)

  • 10.1089/soro.2017.0018

PubMed ID

  • 29412085

Additional Document Info

volume

  • 5

issue

  • 1