Post on 24-Nov-2014
De Montfort UniversityFaculty of Technology
Department of EngineeringMSc. Rapid Product Development
The role of Rapid Prototyping in surgical planning for medical
treatments
Rapid Prototyping ENGT 5132
Prof. David Wimpenny November 2010
Amani FarajStudent ID: 10374103
The role of Rapid Prototyping in surgical planning for medical treatments
Abstract
Technology is a term indicating ways used by individuals to innovate, discover and
develop. For centuries, it has been essential to strive to invent tools, machines,
materials and methods that made work and life easier. From this concept, the need
has come to invent new technologies in all areas such as communication, education,
medicine and industry.
1.There is no doubt that the tremendous advances in manufacturing
technology have had a great impact on many sectors. Given the importance
of the medicine sector, scientists, researchers and any person concerned
directly or indirectly with this area try to utilize the new technologies
provided in this field.One of the best of these technologies which has brought
a remarkable development to medicine is Rapid Prototyping (RP). Its
influence is not limited to production methods and the design of medical
devices, but also RP extends to patient treatment methods. It can be said RP
has broadened horizons to develop and improve conventional techniques
which have been used in clinical approaches. The aim of this paper is to
introduce some of the medical applications of Rapid Prototyping in surgical
planning for treatment means. It will also describe some cases in which RP
has been useful and how it has provided surgeons, doctors and patients with
possible solutions in very complex cases. In other words, how RP can make
differences in patients' lives.Table of ContentsAbstract2Contents3A
bbreviations4Table of Figures51.0 Introduction62.0 Background
63.0 Rapid Prototyping7 3.1 Definition of Rapid Prototyping
73.2 Rapid Prototyping Process Procedures 7 3.3 Rapid Prototyping
Techniques8 3.3.1 Stereolithography8 3.3.2 Fused Deposition
Modeling9 3.3.3 Three Dimensional Printing10 3.3.4 Laser
Sintering11 3.4 Selection of RP Techniques and Materials12 3.5
The Advantages of Rapid Prototyping134.0 The Role of Rapid
Prototyping in Surgical Planning For Medical Treatments…134.1 Rapid
Prototyping and The involved Technologies in the Fabrication of Medical
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The role of Rapid Prototyping in surgical planning for medical treatments
Models14 4.2 Rapid Prototyping for Pre Surgical Training………….…….
……………………….………..15 4.2.1 Stereolithography for pre-surgical
planning models ................................16 4.2.2 Fused Deposition Modeling
for pre-surgical planning models...................16 4.2.3 Laser Sintering
Melting for pre-surgical planning of Cranio-Maxillofacial
surgery……………………………………………………………………………………………………………
….…..16 4.3 Rapid Prototyping for Validating Customized Implants Before
The surgery......18 4.4 Rapid Prototyping for customizing surgical aid
tools .........................................19 4.5 Disadvantages of Using Rapid
prototyping in Medical Applications …...............205.0 Conclusion ................
216.0 References227.0 Appendix24List of
FiguresFigure 1 Flow Chart for RP
procedures........................................................................8Figure 2 Principles
of SLA.............................................................................................9Figure 3
Principles of FDM
technology......................................................................10Figure 4 An
overview of the 3DP
technique..............................................................11Figure (5) an overview of
the LS process...................................................................12Figure (6)
Procedures for medical model
fabrication..................................................14Figure (7) Patient's skull
showing with a tumour......................................................15Figure (8) a
physical titanium implant on patient's
skull.............................................17Figure (9) a mandibular
implant................................................................................17Figures (10a) and
(10b) the physical implant for chin augmentation.........................18Figures
(10c) and (10D) the patient before and after the
operation..........................19Figure (11) Schematic representation of SimPlant
and a SurgiGuide…..………………....20List of TablesTable 1 Comparison between
some of RP methods ..................................................24Table 2 Brief about RP
methods..................................................................................25Abbreviations
RPRapid PrototypingCADComputer- Aided
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The role of Rapid Prototyping in surgical planning for medical treatments
DesignSTLStandard Triangulation LanguageSLA
StereolithographyFDM Fused Deposition Modeling3DP
3 Dimensional Printing LS Laser SinteringLM
Laser MeltingCAM Computer- Aided ManufacturePC
polycarbonateABS Acrylonitrile Butadiene StyrenePPSF
PolyphenylsulfoneCT Computed TomographyCBCT
Cone- Beam Computed TomographyMRI Magnetic
Resonance ImagingDICOM Digital Imaging and Communication in
Medicine2D Two Dimensions3D Three DimensionsUV
Ultraviolet1.0 IntroductionThe development of production and
industrial design processes has become linked to the recent technological
development of computer science that is used in these processes. This
development facilitates the design process and productivity in order to
optimize performance in terms of quality and speed of product delivery. All
this will eventually lead to reducing the time required for modeling and
minimizing the cost. In addition to developments in the aforementioned
related technologies and the correlation with the evolution in manufacturing
processes, intense competition in the global market has led to the invention
of new technologies and the development of existing ones in order to achieve
the maximum profit.2.0 BackgroundIt is generally agreed that there are
three possible methods of creating a part. Firstly, conservative techniques
such as casting and forging, in which there is no need to add or remove
materials. Secondly, subtractive techniques in which the part is produced by
removing unwanted materials to end with the required design. Both these
types of techniques can be considerably expensive and waste materials and
time. Thirdly, additive manufacturing (Rapid Prototyping) which, put simply,
combines parts to build a product part by part. This concept can be cost-
effective by saving the time needed to build a mould and reducing materials
wasted by removing or tooling 1. For decade, it was difficult to apply this
concept until the 1980s due to the inexistence to many factors, for instance,
appropriate materials and computer modeling programs. In the late 1980s,
linked to advances in computer software, the first system of Rapid
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The role of Rapid Prototyping in surgical planning for medical treatments
Prototyping techniques was introduced by 3D System by Chuck Hull in
Valencia, California. It led to a revolution in the industrial sector1. 3.0 Rapid
Prototyping3.1 Definition of Rapid Prototyping Process A simple
description of RP Technique is that it is a process in which the desired
product is built from special materials layer by layer. Each layer, which
represents a cross section of the product, is fused by a laser on a moving
platform. After the layer is built, the platform moves down by the layer's
thickness to start fabricating the next one 2. 3.2 Rapid Prototyping
Process Procedures There are many steps which should be taken in the
RP process, some of them as preparation steps others after the complete part
has been built. These steps, shown in Figure (1), are:CAD modeling: The first
step is that a solid model for the entire part should be prepared as computer-
aided design (CAD) model with all its geometrical specifications .
1. STL generating: in this step, an STL file is created for the 3D model using
specific software such as Materialise Magics to import the 3D CAD model and
break the part surface into triangular facets.
2. Part orientation: an appropriate orientation for the model should be defined.
Many factors should be considered such as accuracy, surface finish, and
reducing supporting materials as much as possible.
3. Supports generation: supporting structures should be generated to the STL
model for overhanging features.
4. Model slicing and path tooling: The next step is slicing the model into layers
and defining the tool path to produce the model on the RP machine.
5. Prototyping production: building the model on the desired machine.
6. Post- processing: finally, the complete model may need to have the
supported structures removed and the surface polished 3.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (1) A flow chart for RP procedures 3.
3.3 Rapid Prototyping techniques
Rapid Prototyping systems can be classified according to the materials which are
used to fabricate the model. From this concept RP technologies are organized as
below:
Liquid-based systems, such as Stereolithography.
Powder-based systems, such as Selective Laser Sintering.
Solid-based systems, such as Fused Deposition Modeling 4.
3.3.1 Stereolithography (SLA/SL)
SLA as shown in Figure (2), it is an RP process in which a part is fabricating in a
container filled with a photopolymer liquid resin as cross-sectional layers. After each
layer is cured by a UV laser, it is bonded to the layer below and the platform is
dropped one layer thickness and then a sweep arm spreads another coat of resin.
This process is repeated until the completed part is formed. Supporting structures
are built during the fabrication of each layer. A wide range of materials is available
for SLA technology either
6
1 .CAD modeling
2 .STL files generation
5 .Model slicing and path tooling
6 .Prototype production
7 .Post -processing
4 .Support generation
3 .Part orientation
Product Design
Final Prototype Model
The role of Rapid Prototyping in surgical planning for medical treatments
from machine manufactures or materials manufactures, such as DSM and 3D
systems. These materials are based on photocurable resins, for example epoxy,
acrylic and polyurethane 5.
Figure (2) Principles of SLA 6.
3.3.2 Fused Deposition Modeling (FDM)
In this technology, each layer of the 3D part is formed by extruding a heated plastic
filament or metal wire in a heated extrusion nozzle. The nozzle is controlled by
computer-aided manufacturing software (CAM) to move in two directions vertically
and horizontally. After the molten material is deposited, it is immediately hardened.
Another head builds supporting structures which can be from materials dissolved in
water or easily removed by hand. Both heads can be in different dimensions and two
coloured materials can be used. Examples of materials used include Acrylonitrile
butadiene styrene (ABS), polycarbonate (PC) and polyphenylsulfone (PPSF) 7.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (3) Principles of FDM technology 8.
3.3.3 3 Dimensional Printing (3DP)
This process has the same principles of additive manufacturing technology. The
complete model is formed layer by layer. The machine deposits a layer of powder on
the platform, then the liquid binder supply (resin), which can be transparent or
coloured, deposits the binder on the layer of the powder as a defined cross-section
of the part. The binder bonds the layer to the one below. The machine repeats this
step until the complete product is constructed. In this process, the model is built
without supporting structures where the unused powder backs up the model and
can be recycled afterwards. After the model is left to cure in the powder, an infiltrant
can be used to improve the model’s properties. This stage depends on the planned
use of the product 9.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (4) A overview of the 3DP technique 10.
3.3.4 Laser sintering method
In this process, the cross section of each layer is formed by using a high power laser
which selectively melts the based powder material on a powder table surface. After
the layer is built, the powder surface is lowered and another layer of powder is
applied on top of the previous one to start producing another layer. The surrounding
unfused powder supports the model; therefore, there is no need to built supporting
structures. The powder can be plastic, metal, ceramic or glass 11. If the materials used
are metals, the process is called Selective Laser Melting, (SLM) 12. Figure (5) shows
the concept of the LS apparatus.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (5) A overview for LS process 13.
3.4 Selection of RP technique and materials
Selection of an appropriate technique, which suits a specific part, can be difficult due
to the limitation of references and the availability of a wide range of techniques.
There are many factors which must be taken into account, for example, cost
(including materials and fabricating time), properties needed for the model, quality,
accuracy and surface finish. In terms of the medical applications of RP, there are
many specifications which should be taken into account. For instance, medical
materials must be biocompatible and inactive such as titanium alloys, due to the
need to implant them into the patient's body, medical models for diagnosing the
disease and understanding the surgical procedures for cancerous regions, which are
made by SLA, should be made from photosensitive resign14. Comparison between
the aforementioned RP methods can be seen in the Appendix, Table 1 and Table 215.
These tables can be used as guidelines.
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The role of Rapid Prototyping in surgical planning for medical treatments
3.5 The advantages of Rapid Prototyping
It should be noted that RP technology has brought breathtaking benefits to the
world market. It can be considered as a revolution in manufacturing sector. Some of
these benefits are:
The ability to produce complex geometric products.
Saving time and money, impliedly, minimizing cost
The capability for use in many sectors such as Medicine, Education, and
Industry.
The ability to detect faults in existing products, enabling correction.
The chance to test features of the product such as function, design
specifications and accuracy.
Involvement of customers in the design process, allowing them to visualize
the complete product 16.
4.0 The role of Rapid Prototyping in surgical planning for medical
treatments
Recent years have seen the widespread use of Rapid Prototyping technology. The
impact of RP technology and related technologies such as CAD, CT, MRI and Mimics
should be grateful and appreciated. The usability of RP can be seen in many medical
fields. In addition to medical devices and instruments, RP is beneficially used in
preoperative planning, surgical aid tools, implants and tissue engineering. It can be
specifically applied to produce customized items for particular patients according to
the condition of their illness.
4.1 RP and the technologies involved in the fabrication of medical
models
In order to process information into an RP machine, there is a need for a medium to
handle the 3D model specifications "Inputs". There are many technological methods
and software packages available in addition to CAD and CAM. Some of the
technologies related to RP are:
Computed Tomography (CT): this is a medical imaging tool which applies a
tomographic technique by using an X-ray source to computationally create a
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The role of Rapid Prototyping in surgical planning for medical treatments
cross-section image of the body of the patient. This technology is particularly
useful for bone imaging 17.
Cone-Beam Computed Tomography (CBCT): this uses the same technical
procedures as CT but it can be more beneficial for soft-tissue imaging and
dental applications 17.
Magnetic Resonance Imaging (MRI): this technique uses a high power
magnetic field and radio waves to generate a cross-section image. Although
it is not effective in bone imaging, in RP, MRI data for soft-tissue and CT data
for bone image can be combined to generate a complete 3D model of a
particular organ or a specific region 17.
Digital Imaging and Communication in Medicine (DICOM): this '' is a standard
for handling, storing, printing, and transmitting information in medical
imaging '' 18.
Medical imaging transferring software: in order to transfer medical image
data obtained from medical imaging technologies such as CT or MRI, accurate
and effective software is required, for instance, Mimics from Materialise NV
(Leuven, Belgium) 19. CT, CBCT and MRI produce the data of the model in a
group of 2D images with extremely small thickness and Mimics is able to
transfer image data which is a DICOM file to a STL file of the 3D model 20.
Figure (6) illustrates common RP procedures for medical model.
Figure (6) Procedures for medical model fabrication 21
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The role of Rapid Prototyping in surgical planning for medical treatments
4.2 RP for pre-surgical training
Until the 1980s, surgeons had to rely on subtractive methods to create a 3D model
by using a milling machine and producing the model by removing the material from a
block. This process was adequate except for producing accurate internal and
external features. These problems were solved in the early 1990s after
Sterolithography was introduced in the late 1980s 22.
Research confirms that the use of Rapid Prototyping in the stage prior to some
complex operations which need accuracy and experience helps surgeons to have a
perceptible view of the steps of the surgery. Producing a model using RP provides an
aid to clinicians in evaluating the operation and making the appropriate decisions. As
a result, simulating and rehearsing the surgery contribute significantly to reducing
the risk to the patient's life. Furthermore, by minimizing the time needed for surgery,
impliedly, this will reduce costs 23.
4.2.1 Stereolithography for pre- surgical planning models
Normally, SLA resins are transparent or translucent. This property can be useful in
producing customized models in which surgeons can see internal features. Coloured
regions can be provided by exposing the required regions to extra UV light after
applying an anti-UV lacquer which does not pass UV light. This technique can be
used to mark vascular structures needed to be avoided during the surgery. Figure (7)
shows the use of SLA to differentiate tumour tissue from the skull bone 24 .
Figure (7) - patient skull showing tumour 25
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The role of Rapid Prototyping in surgical planning for medical treatments
4.2.2 FDM and 3 DP for Pre-surgical planning
The capability to produce models from two heads in the FDM process provides the
clinicians with another solution for producing coloured parts. For example, the first
head which fabricates the part can be used to create healthy regions and the other,
which builds supporting structures, to build cancerous areas. The same capability to
produce coloured parts is afforded by the 3DP process but parts can be created with
more than two colours 24.
4.2.3 Selective Laser melting for Pre-surgical planning of Cranio-Maxillofacial
surgery
Cranio-Maxillofacial injury can be defined as damage to the skull. This disease can
result from many causes, for instance, an infected tumor, an accident (contusion) or
birth defects. The need to reconstruct the damaged area is very substantial whether
for the functional performance of the facial region or the aesthetic aspect. Any
impairment of one or both definitely has an adverse impact on the patient's life.
Rehabilitation of the deformed region needs transplantable tissues or artificial
implants to replace the defective area. If transplanted tissues are available then they
will be the first choice. The patient's bone can be used in reconstructing the
damaged area in the maxillofacial region. However, this choice incurs some risks,
especially for the donor, thus artificial implants from biocompatible materials can be
made to achieve the physical and aesthetic function of the organ 30.In the case of
replacing a damaged area, there are radical required properties which should be
obtainable in the implant materials such as biocompatibility, inactivity and lightness.
Titanium or cobalt-chrome alloys are two of the most compatible materials used to
make implants. Figure (8) shows a model of a patient's skull with an implant printed
on it. Using a SLM apparatus, two implants were produced prior to the surgery for a
patient who had a cranial deformity. The first model for the implant was produced
using polyamide to use as communication tool which provided surgeons, engineers
and the patient with a full understanding of the surgical procedures. The second one
was built from titanium alloy to replace the deformed area 26.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (8) a physical titanium implant on patient's skeleton 26
Figure (9) shows a mandibular implant for a twenty-four-year old man who had
suffered from hemifacial microsomia, which is a birth defect. In this case, there were
specific characteristics which were necessary in the implant material. The implanted
part had to prevent development of bacteria and be light weight to conform to
functional properties. As for the cranial implant, two models were produced by using
SLM. The first was made of polyamide for inspection procedures and the real model
was made of a titanium alloy. Generally, by using RP methods, surgeons become
satisfactorily able to diagnose the disease and then determine treatment method or
how to conduct the surgery 26.
Figure (9) A mandibular implant 26
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The role of Rapid Prototyping in surgical planning for medical treatments
4.3 Rapid Prototyping for validating customized implants before
surgery
In addition to the possibility to simulating the surgery, rehearsing it and how it can
be conducted, RP has enabled surgeons to examine the compatibility of implants
which are needed to replace defective areas and obtain the desired geometric
specifications before the surgery.
In a case study of a woman who needed to augment the size of her chin, an implant
had to be built such that the inner surface must matched the outer surface of her
real chin and the outer surface of the implant had be suitable from an aesthetic
standpoint. In this case, it was necessary to produce a physical model for the
mandible using CT data and exporting it to an RP machine. After the mandible had
been built using the RP technique, the geometric characteristics of the inner surface
of the implant were obtained by using reverse engineering software. The outer
surface was determined by using Magics software from Materialise and a cadaver
mandible, Figure (10a) shows the 3D model of the implant. By gathering all the
geometrical data, a model for the implant was produced and its compatibility to the
model of the mandible examined by fitting it to the mandible model as Figure (10b)
shows. This implant was used to produce positive pattern to make a silicon rubber
mould where a titanium implant was fabricated. Figure (10c) and Figure (10d) shows
the patient before and after the surgery 27.
Figure (10a) 3D implant model Figure (10b) the physical implant for chin augmentation 27.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (10c) the patient before the surgery figure (10-D) the patient after the surgery 27
4.4 Rapid Prototyping for customizing surgical aid tools
Since it has become common to use RP in simulating surgery, as previously
mentioned, keeping in mind its tremendous influence, the optimal utility of it has
become the target of specialists in this area. In addition in inspecting implants and
planning surgery, RP is used to fabricate surgical tools in order to facilitate the
surgery.
This has become widely used in dental treatments where it has become possible to
produce assisting tools to facilitate implant treatments. Beside its capability to
fabricate crowns, bridges and artificial teeth, it can be used to produce surgical drill
guides which help with implant placement process by using special software such as
SimPlant from Materialise. SimPlant is software which uses CT data of the patient's
bone as an input to produce a 3D visualizing model of patient's mandible and create
implant planning with precise positions for implants. SimPlant provides surgeons
with all the important information such as bone density, bite force and sinus graft
volumes. Then, using Stereolithography, customized drill guides are manufactured to
place on the jawbone for accurate drilling and to avoid both nerves and
misplacement as Figure (11) shown 28.
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The role of Rapid Prototyping in surgical planning for medical treatments
Figure (11) Schematic representation of SimPlant and a SurgiGuide 29
4.5 Disadvantages of using RP for medical applications
Although RP has brought radical solutions to critical situations for many patients, in
some cases saving their lives, RP, as any other technology, has its own disadvantages
which can be briefly listed as:
It is costly process. It may be inappropriate to state this process is costly
when the result of it is to save or improve life. This cost is a result of the low
number of machines and cost of materials used to produce the part.
Optimistically, in time this cost will reduce.
In order to fabricate a medical model, special properties are required to be
provided such as biocompatibility and sterility. The available materials do not
always provide the desired degrees of these specifications. Moreover,
mechanical characteristics are poor to some extent, RP models are
considerably brittle and may not be able to shoulder a heavy load.
It is not suitable in an emergency situation when a model is needed urgently.
This technology may be appreciated by doctors and surgeons if it is applied to
long term pre-surgical planning.
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The role of Rapid Prototyping in surgical planning for medical treatments
Because of linking to others technologies from different disciplines such as
engineering, computer sciences and medicine; the RP process needs an
expert technician with sufficient experience in these disciplines. This
technician is unlikely to be available to accomplish all the required tasks of
producing a model, operating and maintaining the machine for RP medical
applications 30.
5.0 Conclusion
As mentioned before, RP has helped patients in finding solutions for complex
problems had adverse effects on their lives. To evaluate the efficiency of RP, it
suffices to indicate the differences which it has brought about in patients' lives. As
can be concluded from the cases in this paper, RP has achieved satisfactory results in
terms of the aesthetic and functional properties of the implants. RP might be
considered a costly technique and it is not affordable for every patient, but as with
any new technology, its cost might drop gradually from its level.
Rapid Prototyping has provided surgeons with chances to rehearse surgeries,
effectively diagnose diseases and to conduct surgeries confidently. As consequences,
they were able to reduce the risk to the patients and reduce the time of operations.
To sum up, regardless of the disadvantages of Rapid Prototyping in medical
applications; the lack of biocompatible materials, cost, and experience requirements,
it can be said that Rapid Prototyping has made a quantum leap in the medical sector
and many promising steps are planned.
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The role of Rapid Prototyping in surgical planning for medical treatments
6.0 References
1 Venuvinod, P.K and Weiyin M. Rapid Prototyping, Laser-Based and other technologies, USA, Kluwer Academic Publishers, 2004, p xi
2 Wimpenny, D, Basic principles of layer manufacturing, Rapid Product Development, De Montfort University, Leicester, 2010.
3 Venuvinod, P.K, P.K and Weiyin M. Rapid Prototyping, Laser-Based and other technologies, USA: Kluwer Academic Publishers, 2004, p 135
4 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,p.57
5 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,p.59
6 Princeton .edu available online at www.princeton.edu/~ cml/assets/images/mems02
7 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,p.75
8 custompartnet.com available online at www.custompartnet.com/wu/images/rapid-prototyping/fdm.png [accessed 23/10/2010]
9 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,p.66
10 custompartnet.com available online at www.custompartnet.com/wu/images/rapid-prototyping/3dp.png [accessed 23/10/2010]
11 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,p.64
12 Wikipedia, Selective Laser Sintering [online] available from http://en.wikipedia.org/wiki/Selective_laser_sintering [accessed 25/10/2010]
13 custompartnet.com available online www.custompartnet.com/wu/images/rapid-prototyping/sls.png [accessed 23/10/2010]
14 Milovanovic, J. and Trajanovic M, Medical applications of Rapid Prototyping, FACTA UNIVERSITATIS, 5, 1, 2007, pp 79-85.
15 Arpetch RP services Selection Guides available online at www.arptech.com.au/srvcompare.htm [ accessed 5/11/2010]
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The role of Rapid Prototyping in surgical planning for medical treatments
16 Wimpenny, D. Basic principles of layer manufacturing, Rapid Product Development, De Montfort University, Leicester, 2010
17 Wohlers, T, Wohlers Report 2008, State of the industry, USA, Wohlers Associates, 2008, p172.
18 Digital Imaging and Communications in Medicine, available online at en.wikipedia.org/wiki/DICOM [accessed 27/10/2010]
19 Gibson, I (editor), Advanced manufacturing technology for medical applications, England, John Wiley and Sons, 2005, pp 70-80.
20 Drstvensek, I Hren, N.I. , Strojnik T , applications of Rapid Prototyping in cranio- maxillofacial surgery procedures, International Journal of Biology and Biomedical Engineering, 1, 2, 2008.
21 Rapid Prototyping Journal, available online at www.Emeraldinsight.com/Journal.
22 Gibson, I (editor), Advanced manufacturing technology for medical applications, England, John Wiley and Sons, 2005, p22.
23 Hopkinson, N, Hague, R.J.M, Dickens, P.M. (editors) Rapid manufacturing an industrial revolution for the digital age, UK, John Wiley and Sons, 2006,pp.(177-178)
24 Gibson, I (editor), Advanced manufacturing technology for medical applications, England, John Wiley and Sons, 2005, pp 6-7.
25 Protomed.net available online at www.protomed.net/planning/tumor.html
26 Drstvensek, I Hren, N.I. , Strojnik T , applications of Rapid Prototyping in cranio- maxillofacial surgery procedures, International Journal of Biology and Biomedical Engineering, 1, 2, 2008.
27 Singare S, Dichen L and Bingheng L, customized design and manufacturing of chin implant based on Rapid Prototyping, Rapid Prototyping Journal, 11, 2, 2005, pp. 113-188
28 Gibson, I (editor), Advanced manufacturing technology for medical applications, England, John Wiley and Sons, 2005, p 92-94.
29 Materialise Dental available online at www.materialise.com/materialise/view/en/2970681-Selected+cases.html
30 Gibson, I (editor), Advanced manufacturing technology for medical applications, England, John Wiley and Sons, 2005, p 13-14.
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7.0 Appendix
FDM SLA SLS CNC 3DP
Relative Cost ( Small to medium size parts )
Relative Cost ( Medium to large size parts)
Accuracy
Functional Prototypes
Presentation Prototypes
Fine & Crisp Feature Detailing
Strength
Material Selection Range
Typical Lead time
Parts with snap fit features
22
POOR AVERAGE BEST N/A
The role of Rapid Prototyping in surgical planning for medical treatments
Water, Chemical, Heat resistance
Metal prototypes direct from machine
Elastomer, Flexible Rubber like parts
Master Models for Tooling
Table (1) Comparison between some RP methods15
FDM SLA SLS CNC 3DP
Brief summary of
the RP Technologie
s
Good combination of strength and surface finish at affordable price and lead time.
Excellent surface finish suitable for presentation, master models and light functional testing.
Range of materials available, soft like rubber to strong like metal. SLS Nylon suitable for snap and living hinge features
Use when mechanical properties can not be compromised with any additive RP process.
Suitable for general purpose parts for initial design stage with a quick delivery.
Table (2) Brief about RP methods15
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