3D Printing Applications in Cardiovascular Medicine

James K Min, Bobak Mosadegh, Simon Dunham, Subhi J. Al'Aref, James K Min, Bobak Mosadegh, Simon Dunham, Subhi J. Al'Aref

• Publisher: Academic Press
• Year: 2018
• ISBN:
  9780128039434
• Topic: Medicine
• Subtopic: Cardiology

3D Printing Applications in Cardiovascular Medicine addresses the rapidly growing field of additive fabrication within the medical field, in particular, focusing on cardiovascular medicine. To date, 3D printing of hearts and vascular systems has been largely reserved to anatomic reconstruction with no additional functionalities. However, 3D printing allows for functional, physiologic and bio-engineering of products to enhance diagnosis and treatment of cardiovascular disease. This book contains the state-of-the-art technologies and studies that demonstrate the utility of 3D printing for these purposes.

• Addresses the novel technology and cardiac and vascular application of 3D printing
• Features case studies and tips for applying 3D technology into clinical practice
• Includes an accompanying website that provides 3D examples from cardiovascular clinicians, imagers, computer science and engineering experts

Chapter 1

History of 3D Printing

Amanda Su^1,2, and Subhi J. Al'Aref^{1,2 1}Department of Radiology, Weill Cornell Medicine, New York, NY, United States ²Dalio Institute of Cardiovascular Imaging, NewYork-Presbyterian Hospital, New York, NY, United States

Abstract

Since its invention 50 years ago, 3D printing technology has progressed at a rapid pace, with significant impact in both the industrial and commercial world. Stereolithography, selective laser sintering, and fused deposition modeling were among the first widely successful methods of 3D printing, initially used for industrial prototyping. 3D printing technology was soon developed for use in a variety of fields, for large-scale manufacturing, engineering of highly complex parts, and even for personal use. In healthcare in particular, 3D printing facilitates more patient-specific interventions, including surgical planning and implant design. Additionally, 3D bioprinting technology plays an integral role in the advancement of tissue engineering and biomedical research. As 3D printing continues to become more sophisticated, it is likely to have a great influence on healthcare in the future.

Keywords

3D printing; Bioprinting; History; Stereolithography

Introduction to 3D Printing

Traditionally, industries used subtractive manufacturing to construct products, whereby designs were carved out of a solid block of material. In contrast, additive manufacturing uses a layer-by-layer technique that allows for more intricate designs and interior modeling. Rapid prototyping was one of the first uses of additive manufacturing. It allowed manufacturers to create prototypes much faster, facilitating the evaluation and testing of designs before producing a finished product. In rapid prototyping, 3D models are first created using computer-aided design software. Machines then construct 3D objects based on that model.

Early Research

The earliest research into the use of photopolymers to create 3D objects took place in the 1960s at Battelle Memorial Institute in Ohio. The aim of the experiment was to polymerize resin by intersecting two laser beams of differing wavelengths. Wyn Swainson applied for a patent in 1971 for a similar dual laser beam approach called photochemical machining [1]. He subsequently founded the Formigraphic Engine Company in California, but this technology never materialized into a commercially available system [2]. In the late 1970s, Dynell Electronics Corporation invented solid photography. This technology used a laser or milling machine to cut cross-sections based on a computer model, and then stack them together to form an object [3].

Beginning of 3D Printing

Hideo Kodama, at the Nagoya Municipal Industrial Research Institute in Japan, was one of the first to develop a rapid prototyping technique using a single laser beam [4]. Though he submitted a patent application for this invention in 1980, it expired without proceeding to the later stages of the Japanese patent process. In 1980 and 1981, he published papers on his experiments to develop methods for automatic fabrication of three-dimensional models using UV rays and a photosensitive resin, using a mask to control exposure of UV source. He described techniques of solidifying thin consecutive layers of photopolymer [5], key aspects of what would later be called stereolithography (SLA) (Fig. 1.1).

In 1984, Charles Hull invented stereolithography. He was issued a patent for stereolithography in 1986, and in the patent described a process in which liquid polymers were hardened under UV light to form cross-sections of a 3D model [6]. This method used digital data and a computer-controlled beam of light to create each layer, one on top of the other. Hull subsequently founded 3D Systems, which eventually produced and sold stereolithography machinery. The first commercial SLA printer in the world was produced by 3D Systems in 1988 [2,3].

Around the same time as Hull's SLA patent, Carl Deckard, at the time still an undergraduate student at the University of Texas, developed the concept of the selective laser sintering (SLS) process. SLS was based on the selective solidification of powder using a laser beam [7]. Deckard went on to found Desktop Manufacturing Corporation (DTM Corp), which produced its first SLS printers in 1992. DTM was eventually acquired by 3D Systems. In 1993, Deckard founded Sinterstation 2000, which launched SLS technology into the industry [8].

S. Scott and Lisa Crump founded the company Stratasys, and in 1989 filed a patent for a form of rapid prototyping called fused deposition modeling (FDM), in which a plastic filament or metal wire was heated in a nozzle and extruded. Its deposition was guided by a computer, based on a predetermined digital model. Each layer was kept at a temperature just below solidification point for good interlayer adhesion [9]. Stratasys eventually developed thermoplastic and printer systems for 3D printing [3].

Figure 1.1 Diagram illustrating the components of a stereolithography system.

Later in 1989, Hans Langer in Germany formed Electro Optical Systems (EOS), with a focus on direct metal laser sintering, which fabricated 3D parts directly from computer design models. This technology used selective exposure of a laser to metal powder for liquid phase sintering [10]. EOS sold its first stereo system in 1994, and is recognized today for industrial prototyping. EOS acquired the right to all DTM patents related to laser sintering in 2004 [11].

In the early 1990s, several other 3D printing techniques were being investigated. Ballistic Particle Manufacturing, patented by William Masters, projected micro-droplets of molten wax material from a jet moving in an X–Y plane to form thin cross-sections. The stationary platform moved in the Z-axis to allow for each layer of the 3D object to be added [12]. Michael Feygin filed a patent for laminated object manufacturing in 1995, which used automated formation of cross-sectional slices from sheet material according to a digital 3D model, then stacking and bonding the layers to form a solid object. However, Feygin's company, Helisys Inc., soon went out of business due to financial difficulties [13]. Solid ground curing was invented by Itzchak Pomerantz, and used an optical mask system to selectively expose layers of photocurable resin. The remaining liquid was then removed and replaced with wax, which was then milled to form a flat substrate for the next layer [14].

In the mid-1990s, the 3D printing industry split into 2 areas of focus: high end for highly engineered complex parts (e.g., medical) and printers for concept development and functional prototyping—user-friendly, cost effective. By the end of the 1990s, only three original companies remained: 3D Systems, Statasys, and EOS [3].

Commercialization of 3D Printing

The patent for Statasys' FDM technology expired around 2005, and subsequently two open source 3D printer projects started: the RepRap Movement and Fab@Home. Both projects had the goal of developing and sharing designs for a 3D printer that was affordable to a wider range of individuals.

Adrian Bowyer, a senior lecturer in mechanical engineering at the University of Bath, started an open source project to create a 3D printer based on FDM technology that became known as the RepRap movement. Bowyer developed designs for a self-replicating rapid-prototyper, and published his designs online and encouraged others to post their improved versions [15,16].

The first printer, Darwin, was released in 2007 and the second, named Mandel, in 2009 (Fig. ...