R_Bibb_Medical_Modelling_The_Application_of_Adv.pdf

60 Medical modelling
systems. Since then, the incredible progress that has been made in computer
processing power and software sophistication has led to the adoption of
CAD/CAM in almost all industries. This rapid growth in the application of
CAD/CAM systems fuelled the growth in the demand for RP systems.
During the 1980s and 1990s the number of RP systems increased dramatically,
and a range of material and process approaches were introduced.
Initially, many of these processes were inaccurate and unreliable leading
to many promising ideas failing to reach the commercial market. Several
processes did secure funding and developed into commercial manufacturing
companies producing RP machines for sale across the world. Since then,
the established technologies have been developed to produce effective,
accurate and reliable machines using a variety of techniques. As with any
other emerging industry, there have been some business failures and some
consolidation of the market with mergers, acquisitions and licensing
agreements.
One of the fi rst casualties from this period was Helisys Inc., manufacturers
of the laminated object manufacturing machines. Although initially
popular, the machines proved unreliable and sometimes even caught fi re.
This led to dissatisfi ed commercial customers and rapidly declining sales
that ended the business.
DTM Corp. had been developing selective laser sintering based on technology
developed at the University of Austin, Texas since the 1980s and
by the mid 1990s had a successful product and good sales. This success
was due in part to the fact that the machine used thermoplastic materials
and, therefore, produced strong and functional prototypes. However, the
company became focused on developing metal materials for use in tooling
applications. This technology was costly and somewhat failed to capture
the interest of the tooling market, which in the main remained faithful to
the increasingly effi cient high-speed milling machines. This and protracted
legal action against the German RP manufacturer, EOS GmbH, adversely
affected the company and it was then acquired by 3D Systems. EOS itself
also suffered from the effects of legal action with 3D Systems, which has
since been resolved.
This has led to an industry dominated by two large USA-based corporations,
3D Systems and Stratasys. 3D Systems was the fi rst major player in
the RP market with stereolithography technology. Good development of
the technology and, importantly, the materials led to the highly successful
SLA-250 model, which provided the company with an installed customer
base and subsequent larger and more effi cient machines. Today SLA ® (3D
Systems Inc., 26081 Avenue Hall, Valencia, CA 91355, USA) is still by far
the most commonly used RP process. The company has strongly followed
a business development strategy, which involved setting up national subsidiaries
in many countries, aggressively protecting intellectual property,