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Design and Development of an Intra-Ventricular Assistive Device For End Stage Congestive Heart Failure Patients: Conceptual Design

Hosseinipour, Milad
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372726495

Abstract Details

2013, Master of Science, University of Toledo, Mechanical Engineering.
A novel intra-ventricular ventricular assistive device (VAD) for end stage heart failure patients is presented here. VADs are approved by FDA as Bridge to Transplantation Therapy, Bridge to Recovery Therapy and permanent or Destination Therapy for patients at NYHA Class IV level as an alternative to heart transplant. While all current devices need an open heart surgery, this new flexible structure enables a transcatheter implantation and therefore eliminates the thoracotomy. This also addresses the problem of anatomical fit for smaller adults and children, which is a limitation for many of the current VAD systems. Low energy consumption and similarity of the structure to currently available cardiac defibrillators makes the transcutaneous energy transmission (TET) possible, which reduces the possibility of infection significantly. Using flexible, biocompatible smart materials such as Ionic Conducting Polymer Metal Composites (IPMC) and Shape Memory Alloys (SMA) to actuate the device reduces the number of mechanical parts implanted. Compared with other ventricular assistive devices or total artificial hearts the absence of pistons, impellers, bearings, housings, bladders and valves makes the manufacturing, inspection and maintenance processes much simpler. The device will also reduce the risk of calcification, wearing out or other mechanical failures. Moreover, by mimicking natural motion of the heart, the device exerts almost no shear stress on blood cells and leaves no stagnant points, hence reduces the risk of hemolysis and thrombosis. Actuators, sensors, driveline, and drive unit are the main parts of the device. The actuator sits at the bottom of the ventricle and replicates the motion of the heart by squeezing and upward-downward motion. It may perform one or both of the motions based on the level of assistance needed. Different combinations of these motion mechanisms provide high, medium or low level of pressure increment and volume displacement based on the physiological needs and dependency of the patient on mechanical circulatory support system. Currently available VADs are riddled with many issues. A comprehensive review was performed on all available total artificial hearts, ventricular assistive devices and heart restraint methods. Advantages and disadvantages of each device were investigated. Since a precise model representing the non-geometric inner shape of the ventricle is essential for predicting the working environment and space limitations, a 3D CAD model was extracted from MRI of a real subject. Hemodynamics of an eligible patient was then examined to define the average working conditions and physiological needs. Next, different motion mechanisms were evaluated to find the one with maximum volume displacement, mimicking natural motion of the heart. Several actuators and actuation mechanisms using novel actuation materials were then studied. Different possible designs for actuators were then introduced to represent the possibility of utilizing active materials to perform desired motions and address the cardiac insufficiency. A combination of IPMCs and SMAs was chosen as the actuation mechanism. As the preliminary evaluation of the device, FE solution of the governing differential equation of the electrochemical-mechanical behavior of IPMCs was used to check the compliancy of IPMCs with those needs defined by hemodynamics and motion analyses. One-dimensional results of the FEM solution were extended to 2D to find the tip displacement of a flap IPMC actuator and were then experimentally verified. Finally, actuator embodiments were validated by FEA on Shape Memory Alloy actuators.
Mohammad Elahinia, PhD (Advisor)
Efstratios Nikolaidis, PhD (Committee Member)
Lesley Berhan, PhD (Committee Member)
198 p.
Biomechanics; Biomedical Engineering; Biomedical Research; Engineering; Fluid Dynamics; Materials Science; Mechanical Engineering; Mechanics; Medical Imaging; Rehabilitation; Surgery; Therapy
heart; congestive heart failure; ventricular assistive device; ionic polymer metal composite; shape memory alloy; smart material; finite element analysis; CAD modeling; total artificial heart; actuator; experiment; hemodynamic; MRI; heart restraint method

Recommended Citations

Citations

  • Hosseinipour, M. (2013). Design and Development of an Intra-Ventricular Assistive Device For End Stage Congestive Heart Failure Patients: Conceptual Design [Master's thesis, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372726495

    APA Style (7th edition)

  • Hosseinipour, Milad. Design and Development of an Intra-Ventricular Assistive Device For End Stage Congestive Heart Failure Patients: Conceptual Design. 2013. University of Toledo, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372726495.

    MLA Style (8th edition)

  • Hosseinipour, Milad. "Design and Development of an Intra-Ventricular Assistive Device For End Stage Congestive Heart Failure Patients: Conceptual Design." Master's thesis, University of Toledo, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372726495

    Chicago Manual of Style (17th edition)

toledo1372726495
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© 2013, all rights reserved.
This open access ETD is published by University of Toledo and OhioLINK.