Bioengineering and Biomaterials in Ventricular Assist Devices

Eduardo Guy Perpétuo Bock

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000462890
• Edition: 1
• Topic: Medicine
• Subtopic: Cardiology

Often associated with artificial hearts, ventricular assist devices (VADs) are blood pumps that can provide circulatory assistance to the left ventricle, the right ventricle, or both. Bioengineering and Biomaterials in Ventricular Assist Devices reviews constructive details of VADs and the biomaterials used in their development and support.

FEATURES

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• Establishes an area of intersection between engineering and medicine

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• Shows process development from mechanical design to automation and control

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• Discusses biofunctional materials, tribology in ceramic biomaterials, biosensors, and surface engineering and blood

This text is aimed at advanced students, researchers, and practicing engineers conducting work on VADs and will be of interest to a broad interdisciplinary group, including bioengineers, materials engineers, chemical engineers, mechanical engineers, and electrical engineers.

Part I

Bioengineering in Ventricular Assist Devices

1 VAD Design

Aron J. P. Andrade and Gustavo C. Andrade

Instituto Dante Pazzanese de Cardiologia

Juliana Leme

Dental Morelli

Bruno U. Silva

Universidade São Judas Tadeu

CONTENTS

1.1 Author’s Experiences—How It Began

1.2 Ventricular Assist Device (VAD)

1.3 Rotor Geometry

1.4 Hemolysis and Thrombosis

1.5 Computational Fluid Dynamics (CFD)

1.6 Transventricular Assist Device (TVAD)

1.7 Apical Aortic Blood Pump (AABP)

1.8 Temporary Ventricular Assist Device (TVAD)

References

1.1 AUTHORS’ Experiences—How It Began¹

Dr. Aron Andrade is a co-editor for Central and South America for Artificial Organs. Dr. Aron Jose Pazin Andrade is one of the pioneers in mechanical circulatory support in Latin America. Before finishing mechanical engineering school in 1983, he began his student-training program at the Institute Dante Pazzanese of Cardiology (IDPC), an important research and healthcare center maintained by the Government of the State of São Paulo. There he developed a cardiovascular simulator for prosthetic heart valve evaluation. After getting his diploma in 1985, he was admitted as an engineer at IDPC—Department of Bioengineering—and also began his master’s degree program at the University of Campinas, performing comparative assessment studies with different cardiac prosthetic valves. He became the head of the Biomechanical Laboratory in 1990, where the development of many types of prostheses, medical devices, and surgical instruments occurred—great contributions to Brazilian cardiology. In 1995, Dr. Andrade’s PhD thesis sent him to the Department of Surgery at Baylor College of Medicine in Houston, TX. There, under the tutelage of Prof. Yukihiko Nosé, Dr. Andrade began the evaluation of a new model of centrifugal blood pump for cardiopulmonary bypass (CPB), which became known and patented as the Spiral Pump. At Baylor, he had the opportunity to join Prof. Nosé’s research group. He helped to improve and to evaluate an electromechanical total artificial heart (TAH) and to test an implantable centrifugal pump under development at that time. Just before returning to Brazil, Dr. Andrade proposed a new project of an artificial heart to Dr. Nosé, but not an orthotopically implanted device such as Baylor’s model: Dr. Andrade proposed a heterotopic artificial heart, the so-called auxiliary TAH (ATAH). Back at IDPC, he began to work on this new ATAH based on the same electromechanical principle as Nosé’s TAH, but with new design features, technologies, and different applied materials. The main purposes of the ATAH were to have easier and faster implantation without removing the patient’s natural heart; to have a more effective device controller as it would need only to follow the natural heart rate using a full empty control mode; to provide safer application as the natural heart still can maintain a patient’s blood circulation in case of a catastrophic device failure; and to maintain the possibility of native heart reverse remodeling. The ATAH project grew and became his main PhD thesis subject, which was concluded in 1998. A few years later, the first ATAH prototypes were prepared for initial preclinical trials and the external components as the batteries system and controlling system were completely functional. During ATAH development, Dr. Andrade also started his work on the dissemination of artificial organs information in Latin America. In 1998, he founded a scientific society called LASAO—Latin American Society for Artificial Organs and Biomaterials, with important help from his colleagues. In the same year, the first LASAO congress was held in Belo Horizonte, Brazil, with 409 attendants and 107 presentations. From 2001 to 2004, Dr. Andrade was the head of LASAO and after that became a member of its Board of Trustees. LASAO has published three peer-reviewed special issues for Artificial Organs, presenting selected articles from its congresses. During this period, Dr. Andrade, his students, and colleagues started several other projects in mechanical circulatory support, biomedical engineering, and cardiology. These projects, including the ATAH, caused Dr. Andrade to become renowned as a successful professional, professor, and researcher in Brazil and in Latin America. In 2009, Dr. Andrade created and became the head director of the “Engineering Center of Circulatory Assistance” (ECCA), the first center in Latin America exclusively dedicated to the development of blood pumps and devices for mechanical circulatory assistance. At ECCA, his research associates and students began new projects such as implantable centrifugal pumps and mixed flow blood pumps for left ventricle assistance, CPB and temporary ventricular assist devices, device controllers and controlling system software, and a hybrid cardiovascular simulator for blood pump evaluations. The implantable centrifugal blood pump is in preclinical trials, and a new remodeled version of the Spiral Pump is approved for CPB. Currently, Dr. Andrade is a professor teaching materials science and biomedical technology at FATEC—College of Technology (since 1992)—and USP—University of São Paulo (since 2007), where he is a PhD program adviser in Cardiovascular Technology. He has published over 240 articles, 5 book chapters, 15 technological products, and 8 patents and has received 20 awards and titles. Dr. Andrade continues to organize the COLAOB Special Issue in collaboration with Artificial Organs.

¹ Presented by Paul S. Malchesky, DEng Editor-in-Chief of Artificial Organs.

1.2 Ventricular Assist Device (VAD)

The development of blood pumps goes through design steps, prototype construction, in vitro evaluation, in vivo evaluation, clinical evaluation, and release for use. These items are included in the international standard ISO 14708—Implants for Surgery—Active implantable medical devices—Part 5: Circulatory support devices, 2010 (ISO 14708-5, 2010). This standard deals with a regulatory item of definitions, specifications, tests, and documentation for the development of all procedures and is already applied in Brazil as ABNT NBR ISO 14708-5: 2017.

Regarding the development (geometry and dimensions), the standard is not specific. It shows a methodology of step-by-step development, based on the progression of experiments and improvement of the project through preliminary results, the same proposed by Dr. Nosé in 1998 (ISO 14708-5, 2010; Nosé, 1998). In other words, the development is at the discretion of the ideology of the researcher, and from the results of the tests proposed by ISO 14708-5, changes are made in the project, which may result in a product different from the original and even for other applications.

For the development of blood pumps, it is necessary to understand how they are classified, which may be in terms of the type of pumping, the mode of activation, its location in the patient, and its applicability.

As for the type of pumping, the pumps can be pulsatile and nonpulsatile.

• Pulsatile: The blood flow occurs due to the movement of a diaphragm associated with the use of mechanical or biological artificial valves, which allow the unidirectional passage of blood (Nosé & Motomura, 2003);
• Nonpulsatile: The continuous flow can be generated by radial or axial drive:
  • Nonpulsatile radial drive pumps (centrifuges) promote a blood flow perpendicular to the pump rotation axis. Intake is performed by the center of the pump where the inlet connect...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword: What Is “Social” about Artificial Hearts?
• Editor
• Contributors
• Introduction
• PART I Bioengineering in Ventricular Assist Devices
• PART II Biomaterials in Ventricular Assist Devices
• Index