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INDEPENDENT STUDY MODULE

MEDICAL RAPID PROTOTYPING

TECHNOLOGIES & DESIGN FOR

HIP IMPLANTS USING CAD


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JAMES CLARK

BSc CAD YEAR 3

CONTENTS

INTRODUCTION & JUSTIFICATION ................................................ ............................ 3

RESOURCES ............................................................................................................... 6

RAPID PROTOTYPING INTRODUCTION .................................................................... . 7

Rapid Prototyping Process .................................... ......................... ...................... 8

Rapid Prototyping History ................ .......................... .......................... ................. 9

HIP REPLACEMENT INTRODUCTION ....................................................................... 12

Hip replacement History ................ .......................... .......................... ................. 14

RAPID PROTOTYPING TECHNOLOGIES .................................................................. 16

Stereolithography .................................................. Error! Bookmark not defined.

Selective Laser Sintering ................ .......................... .......................... ................. 17

Fused Deposition Moulding ............................................................. .................. 18

Electron Beam Melting ...................... .................... .......................... ................... 19

Solid Ground Curing ...................... .......................... .......................... ................. 20

CAD CAM ............................................................................................................... 22

3D Modelling Software .......................................................................................... 23

CAD Models ...................... ...................................................................................... 25

Model 1 ...................... .................... .......................... ......................... ................... 25

Creating Model 1 ...................... .......................... .......................... .................. 26


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Finished Model 1 ................................................................................................. 31

Model 2 ...................... .................... .......................... ......................... ................... 32

Creating Model 2 ...................... .......................... .......................... .................. 33

Finished Model 2 ................................................................................................. 38

CONCLUSION ...................... ................................................................ .................... 39

REFERENCES ............................................................................................................ 40

TABLES ...................................................................................................................... 42

FIGURES ...................... .......................... .......................... .......................................... 43


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INTRODUCTION & JUST IFI CAT ION

A report will be written on a study of medical rapid prototyping for hip

replacement using CAD software. The author has previously studied rapid

prototyping methods for an HND report at Motherwell College; the author has

a close family member who has recently undergone their second hip

replacement which has influenced him to increase his knowledge and

comprehension in this discipline using the study of medical rapid prototyping

for hip replacement using CAD software.

This reports purpose is to research the advancement of hip replacement in

the medical industry since the introduction of Computer Aided Design and

3D rapid prototyping. The report will explain how 3dimentional modelling

software (CAD) has changed the development and manufacture of

orthopaedic implants. The report must meet the requirements of the

Individual Study Module at the University of Paisley.

The aim of this report is to produce a 3D CAD model of a replacement

orthopaedic hip that a Rapid Prototyping machine can form into a fully

functional implant. This will be done after research into Rapid Prototyping and

advancement in hip replacement has been conducted by the author.


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The report must meet the requirements of the Individual Study Module at the

University of Paisley.

There are four parts to the structure of this report; the first feature is an

introduction to Rapid Prototyping which will explain the requirements

involved for each process, the history of Rapid Prototyping Technology, Its

applications and the materials that are used to create models. There will be

an introduction to hip implants and the history behind the operation.

The second section will comprise of different Rapid Prototyping methods,

from the knowledge that the author has gained in researching this subject he

will convey to the reader a description of the different Rapid Prototyping

systems that he has obtained knowledge of. An abridged clarification of

each system and the manner in which they perform will be given with their

file types, compatibilities, cost, advantages, disadvantages and operating

time.

Stereo lithography

Selective Laser Sintering

Fu sed Deposition Mo u lding

Electron Beam Melting

Solid Gro u nd C u ring


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The third section of the report will consist of the technology used in

determining the dimensions of the hip through CT scans, some of the software

that is applicable and 3D models that the author has created using Autodesk

Inventor. These models are representations of the hip Implants that have

been discovered through his research. From the information and knowledge

gained in the process of constructing this report these models will be

constructed and displayed with the appropriate information and illustrations.

The fourth section concludes the report with a review from the author to

demonstrate that the purpose and aims of the report have been achieved

and what the author has learned from the study.


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RESOURCES

The author has listed below some resources that will be utilised in the research

for this report.

Mitchell Library C ITY OF G LASGOW S MAIN L IBRARY

UWS Paisley L IBRARY

Athens H TTP :// AP 7. AUT H . AT HE NSAMS . N E T / MY / R E SOURC E S

British Medical Journal H TTP :// WWW . BMJ . COM /


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RAPID PROTOTYPING INTRODUCTION

Rapid prototyping (RP) is a technology that can automatically produce a

physical prototype (Figure 1) from a Computer Aided Design (CAD) drawing.

Having this technology enables designer to quickly create a quantifiable

prototype that can be physically held, these models make excellent visual

aids for conveying ideas with other designers or clients. Additionally

prototypes can be used for design testing before being put into

manufacturing which dramatically reduces the cost to the company. The

technology has advanced to a point that some models can be

manufactured to production-quality. These reasons are making RP machines

more popular as the technology evolves.

Figure 1, image shows the process from CAD to Printer to Prototype

(HTTPWWW .DESKTOP -3 DPRINTERS .COM 3D -PRINTING -EXPLAINED )


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Rapid Prototyping Process

The physical models are automatically constructed with the aid of additive

manufacturing technology; the process is initiated from the RP machine

(Figure 2, 3) interpreting CAD data being fed with the required design. These

designs are further converted into wafer-thin horizontal cross sections of the

model; the process is then repeated creating successive layers continuously

until the completion of the prototype. There are different methods and

materials used in rapid prototyping but the process is basically the same.

HTTP :// WWW .ZCORPORATION .COM /EN /HOME .ASPX

Figure 2, Image of 3D printer HTTP :// WWW .ZCORPORATION .COM /EN /HOME .ASPX


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Rapid Prototyping History

The history of Rapid Prototyping starts in the late 1960s when automated

machines where just establishing their importance in the evolution of industry

once introduced to the factory floor. A professor of engineering at the

University of Rochester called Herbert Voelcker examined the boundaries of

controlling automated machine tools with computer programing. To do this

he developed the basic tools of mathematics that could be programmed

into design software and clearly translated into the desired format. The

algorithmic and mathematical formula that he produced resulted in the

principles that govern basic solid modelling in most 3D software packages.

HTTP :// WWW .MAE .CORNELL .EDU /PEOPLE /PROFILE .CFM ? NETID =HBV 1

HTTP :// ENGG .HKU .HK /MONG /AVOELCKER .HTML


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1986 4575330

Apparatus for production of three-dimensional objectsby stereo lithography

Hull;CharlesW.

UVP, Inc.licensed to3D Systems,Inc.

stereolithography

Charles W. H u ll is recognised as the creator of rapid prototyping as he

patented Stereo lithography on March 11 th 1986, (Table 1) these models are

produced by an ultraviolet beam curing a layer of liquid polymer into a solid.

Once a layer has been cured it drops to let another layer of polymer be

struck with the light, this action is continued until the process is complete.

4575330: Apparatus for production of three-dimensional objects by stereo

lithography

INVENTORS: Hull; Charles W., Arcadia, CA

ASSIGNEES: UVP, Inc., San Gabriel, CA

U.S. CLASS: 425/174.4

Table 1, Charles W. Hull patent Stereo lithography on March 11 th 1986HTTP :// WWW .ADDITIVE 3D .COM /MUSEUM /MUS 2. HTM


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In 1987, researcher Carl Deckard from the University of Texas developed a

layer based manufacturing procedure that used Voelcker s formula to

translate a virtual simulation into a physical prototype. This became patented

as Selective Laser Sintering (Table) technology that produced a 3D solid from

design software, constructing the prototypes form using a high powered

laser to unify metallic, ceramic, glass or plastic particles into a solid formation.

1989 4863538

Method andapparatus for

producing partsby selective

sintering

Deckard;Carl R.

Board of Regents, TheUniversity of Texas Systemlicensed to DTM, Inc.

subsequently acquired by3D Systems

selectivelaser sintering(SLS)

4863538: Method and apparatus for producing parts by selective sintering

INVENTORS: Deckard; Carl R., Austin, TX

ASSIGNEES: Board of Regents, University of Texas System, Austin, TX

U.S. CLASS: 156/062.2

HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS _2. HTM

Table 2, Carl R. Deckards patent for Selective Laser Sintering in 1989 HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS 2. HTM


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HIP REPLACEMENT INTRODUCTION

Hip replacements are among the most

commonly used orthopaedic techniques

that are carried out in the field of surgical

medicine, the procedure has been

performed on hundreds of thousands of

patients for over fifty years. The surgery is

required when the original joint is

dysfunctional or arthritic (Fig 3) which

causes restriction in movement and

crippling pain.

During replacement the head of the thigh bone (femur) is removed, a metal

cup is then positioned in the socket (acetabulum) which can occasionally be

fixed with 1, 2, or even 3

screws. A plastic, metal or

ceramic insert is placed;

a metal stem is inserted

into the femur with a ball

fitted on top. The

diameter of the ball can be

J MED J 2008; J UNE : VOL . 42(2) HTTP : DAR . J U.EDU . J O J M J

Figure 3, Image of an arthritic hip


Figure 4, Image shows the stages of a total hip replacement

J MED J 2008; J UNE : VOL . 42(2) HTTP : DAR .J U.EDU . J O J M J


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Anything from 28mm to 58mm and made from metal or ceramic, this is then

fitted into the cup creating the new joint.

Using metal alloys, high-grade plastics, and

polymeric materials in the artificial hip joints has

resulted in the increased success in of the

biomechanical integration with the host.

Function and longevity have dramatically

increased with the introduction of modern

materials and the technology involved in their

incorporation into the medical industry.


Figure 5, Image showing how theimplant is fitted.

J MED J 2008; J UNE : VOL . 42(2) HTTP : DAR . J U.EDU .J O J M J


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Hip replacement History

The history of hip replacement starts in 1925 when a surgeon in Boston,

Massachusetts, Marius N. Smith-Petersen, M.D. fashioned a piece of glass into

the shape of a hollow hemisphere with the idea in which it would fit over the

ball of the hip joint providing a new smooth surface for improved movement.

These factors were successful as well as the biocompatibility but the glass

could not endure the stress put upon it while walking.

In 1936 the invention of a cobalt-chromium alloy that had the vital

combination of properties for success was invented. The next step in the

evolution of the implant occurred when a complete ball of the hip was

developed by Frederick R. Thomson of New York and Austin T. Moore of South

Carolina.

Sir John Charnley a master surgeon from England

was trying to solve the same issues, during his

research he became the object of ridicule from his

peers to a point where he was ostracised, he still

managed to carry on his work in a hospital that was

converted from a tuberculosis sanatorium.Figure 6, Image of Sir

John CharnleyHTTP :// RHEUMATOLOGY .OXFORD J OURNALS .ORG /CONTENT /41/7/824. FULL


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This is where he tried Teflon for the first time but did not achieve the desired

results; after this he borrowed a material called

polymehtylmethacrylate from a dentist, this material was also known as bone

cement, the results obtained from this were set to be the starting point of the

Total Hip Replacement, procedure that is performed in present day theatres.

HTTP :// WWW .HIPIMPLANTATTORNEYS .COM /H IPIMPLANTS .HTML

HTTP :// RHEUMATOLOGY .OXFORD J OURNALS .ORG /CONTENT /41/7/824. FULL


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RAPID PROTOTYPING TECHNOLOG IES

Stereo lithography

Commercially this was the first of the

R.P processes and is still the most

frequently used in industry today.

The process begins the same way as

all the other R.P machines with some

form of CADD drawing file being

loaded into it. The machine uses the

file information to laser the CADD

drawing onto the surface of liquid

photopolymer a layer at a time. After

each layer is complete the basin is lowered and the laser outlines another

layer, every section is bonded together as the liquid is self-adhesive. All parts

have overhangs and undercuts that have to be supported which the

software does automatically by fabricating them. Once the model is

completed and removed from the machine they can be dethatched

leaving the finished model.

HTTP :// WWW .CUSTOMPARTNET .COM /WU /IMAGES /R PROTOTYPING /SLA .PNG /28/11/2011

Figure 7, Image showing the process of Stereo lithography

HTTP :// RAPID -PROTOTYPING .HARVEST -TECH .COM /MATERIALS _SLA. HTM


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Selective Laser Sintering

This manufacturing process involves a

high powered laser that fuses small

particles of materials (metal, plastic,

ceramic or glass) in a powder form into

a solid 3 dimensional model. This

technique is accomplished by data in

the format of a drawing file being

loaded into the machine then the top of

the powder bed is scanned with the

drawing file layer by layer. As each of the

layers is finished the bed drops ready for

the next this process is repeated until the model is complete.

HTTP :// EN .WIKIPEDIA .ORG /WIKI /S ELECTIVE _ LASER _ SINTERING

Figure 8, Image showing SLS methodHTTP :// WWW .ARPTECH .COM .AU /SERVICES /SLSDIAG .GIF /28/11/2011


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Fu sed Deposition Mo u lding

Once the CADD drawing has been loaded via an STL file the machine starts

to build the model layer by layer. Unlike the previous methods these layers

are formed by a thermoplastic being fed out through the end of a heated

nozzle. The model is built up

instead of a tray being full of the

compound and dropping every

layer. The layer is fed onto it a

support base and columns. When

the model is completed the base

and columns can be removed

leaving only the finished 3D form.

HTTP :// WWW .MATERIALISE .COM /FUSED -DEPOSITION -MODELLING

Figure 9, Image showing the FDM methodHTTP :// WWW .MATERIALISE .COM /FUSED -DEPOSITION -MODELLING


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Electron Beam Melting

This type of R.P is for metal parts as in the

other methods items are manufactured

from a 3D CAD model file being loaded

on the machine. Then a laser melts

metal powder layer by layer, the

difference with EBM is that the parts are

created in a vacuum making them fully

dense and thus suited for manufacture

in reactive materials. The powder is a pure

alloy of the models chosen material this

omits the need for further heat treatment to

achieve the properties of a mechanical part.

H TTP :// WWW . EE TIM E S .COM / D E SIGN / INDUSTRIAL -CONTROL /4013703/R APID - PROTOTYP E S -

MOV E -TO - M E TAL -COMPON E NTS

Figure 10, Image showing the EBM methodHTTP :// EN .WIKIPEDIA .ORG /WIKI /E LECTRON _B EAM

_M ELTING


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Solid Gro u nd C u ring

SGC uses photosensitive liquid in a layer by layer process; however the main

difference is that it exposes an entire layer at one time. Before the process

can begin, a series of plates must be printed. Software splits the CAD model

up into thin layers, and each layer is printed (2-dimensionally) onto a plate.

The plate acts as a mask; any model cross-section is transparent while the rest

of the plate is

opaque. The

machine first

sprays a layer of

photopolymer

into the working

area. The first

printed plate is

loaded right below a UV

lamp; a shutter opens and

the entire plate is exposed

to the photopolymer at once. The cross-section that was exposed hardens

the photopolymer, and afterwards the uncured photopolymer is sucked up

by a vacuum. Next a layer of wax is put down over the unexposed area

(evening out the bed) and the entire layer is milled so that it is completely flat

(all of the excess material from the milling stage is vacuumed up).

Figure 11, Image shows the SGC method

J OURNAL OF MANUFACTURING SYSTEMS VOL . 21/W O.6 2002


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Another layer of photopolymer is sprayed on, the next plate is loaded, and

the process continues. At the end the model is contained within a block of

wax, which gets melted away. No other post processing is necessary.

J OURNAL OF MANUFACTURING SYSTEMS VOL . 21/W O.6 2002


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CAD CAM

Recently computer navigation has been used for hip replacement, CAD

CAM (Custom Aided Design Custom Aided Manufactured Hip) the key to this

innovation is medical imaging with a CT scan. Medical images in 3D solid

models have become an immensely important tool for viewing the internal

structure of the human body and helping doctors quickly and accurately

diagnose illness. All reconstructed 3D solid models can be converted to RP

physical models through CAD software such a Pro/Engineer or Autodesk.

When the CT scan is used for the hips construction all of the appropriate

dimensions are recorded (Figure 7, 8) and duplicated as there may be some

forms of abnormality in the bone structure. Modeling each the implant is an

individual task designated to the patient, this is the reason for the accuracy in

the geometry.

R E PRINTS @ E M E RALDINSIG H T . COM

Figure 12, Geometry assessed with theuse of touch probe scanner

REPRINTS @ EMERALDINSIGHT .COM

Figure 13, Geometry assessed with theuse of touch probe scanner

REPRINTS @ EMERALDINSIGHT .COM


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3 D Modelling Software

There is several different 3D modelling software packages available that are

used to design a wide range of components for industry, the designs are

simple geometry that is built into a 3D model with the use of the systems tools.

Pro/Engineer is powerful modelling software that is widely used in the design

and engineering that is needed in the manufacturing of a many complex

projects. Sophisticated tests can be carried out on the models to ensure they

are to a standard that satisfies the pro forma specifications before it goes into

production.

Figure 14, Screenshot of Pro/Engineer user interface ( PTC. COM )


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The author has knowledge of Pro/Engineer through his studies at University of

Paisley that started in October of this year; accordingly his level of

competence and experience in the software is limited.

The author has a good working knowledge of Autodesk Inventor through his

previous studies in CAD and has found the execution of the design tools are

similar to Pro/Engineer but their layout is still unfamiliar. For these reason the

author will use Autodesk Inventor to create a 3D model of a hip replacement

as there are some complex modeling techniques involved in its production.

Figure 15, Autodesk Inventor User interface ( DESK E NG .COM )


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CAD Models

Model 1

There are two hip replacements that will be

modelled, the first (Figure 16) is a model of a

femoral prosthesis that was designed and

developed at the University of Aveiro. The

geometry of the implant is determined using

a touch probe system. (Page 22 Figures 12

and 13) This ensures the correct parameters

were met within the accepted tolerances.

The author has selected this implant to

replicate using Autodesk Inventor as it is a

feasible option that could be modelled within the parameters of his skill and

knowledge of the software.

WWW . E M E RALDINSIG H T .COM / R E PRINTS

Figure 16, Image shows a CAD modeland the master mould that is

produced from it

WWW .EMERALDINSIGHT .COM /REPRINTS


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Creating Model 1

Autodesk Inventor software is opened and a new project is initiated with the

name Ramos Hip , then a (mm ipt) standard part file is created for the model .

The first step in producing the implant representation is for its geometry to be

sketched in 2D and constrained to the workspace, (Figure 17) this gives a

fixed point for

the model to

be

constructed.

Finishing the

sketch leads

to the

modelling

stage, this

allows the geometry to be manipulated through the use of the tools

available. (Figure 18)

Figure 17, Screenshot of Autodesk Inventor showing the first

basic geometry of the Ramos Hip ( J AMES CLARK )

Figure 18, Screenshot of Autodesk Inventor modelling toolbar ( J AMES CLARK )


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This stage of the process involves the loft tool which was used in making the

top part of the model that connects to the socket. (Figure 19) Loft creates

complex and organic shapes such as those found in the automotive, marine,

and consumer products industries.

Figure 17, Screenshot of Autodesk Inventor showing the loft tool producing the first part of the model ( J AMES CLARK )


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Figure 18, Screenshot of Autodesk Inventor showing the loft between 2

planes ( J AMES CLARK )

The next part is produced using the

profile from the preceding command

as the first source of reference for the

loft tool, the second point of reference

is created from a projected plane that

sits parallel to the first. (Figure 20) This

plane has the desired geometry of the

next segment it will be connected.

The next tool used in the construction of

the model is Extrude, (Figure 21) this

command can increase the height or

length of any chosen profile in a positive

(adding to the profile) or negative.

(Subtracting from the profile)

Figure 19, Screenshot of Autodesk Inventor showingExtrude command ( J AMESCLARK )


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The command that will be used in the next

part is rotate, (Figure 22) this is done by

selecting the desired profile that has to be

rotated, then choosing the axis for it to be

rotated from in order to accomplish the

desired curve.

The images shown next have been constructed with the use of previously

explained commands; each image will have a written insertion bellow of the

command used to create it.

Figure 20, Screenshot of Autodesk Inventor showing revolve command ( J AMESC LARK )

Figure 21, Screenshot of Autodesk Inventor showingExtrude command ( J AMESCLARK )

Figure 22, Screenshot of Autodesk Inventor showingRotate command ( J AMESCLARK )


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Finished Model 1

Figure 26, Screenshot of Autodesk Inventor showingthe finished model ( J AMES CLARK )


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Model 2

The second model is of a custom hip design

form Stanmore Implants. Each individual unit is

made to the specific measurements of each

recipient from young children to adults; every

size of person can be accommodated as all

parts of the geometry can be modelled to suit.

This is accomplished using a touch probe

system. (Page 22 Figures 12 and 13)

The author has opted to replicate this design

using Autodesk Inventor as it is a feasible model

that could be fashioned within the parameters of his skill and knowledge of

the software.

Figure 27, Image of customimplants from:

HTTP :// WWW .STANMOREIMPLANTS .COM /CUSTOM -HIP -IMPLANTS .PHP


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Creating Model 2

Autodesk Inventor software is opened and a new project is initiated with the

name C u stom Implant , then a (mm ipt) standard part file is created for the

model . The first step is sketching the basic geometry that can be

manipulated using the modelling tools; (Figure 28) shows this step with the

outline of the

lower shaft.

The next step is to use the sweep command

following the desired curve of the model;

the result is the lower part of the model that

inserts into the femoral bone. (Figure 29)

Figure 28, Screenshot of Autodesk Inventor showing the basicgeometry of the lower shaft of the model ( J AMES CLARK )

Figure 29, Screenshot of Autodesk Inventor showing the basicgeometry being manipulated withthe sweep tool ( J AMES CLARK )


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The sweep command is used in this step by

using the profile created by the previous

sweep, this profile is instructed to follow an arc

in the opposite direction to the first, (Figure 30)

This constructs the centre of the shaft.

The top part of the shaft is created with the

revolve tool, the end profile from figure 30 is

used with the required radius (Figure 31)

and then revolved with a measurement in

degrees. The input of the degree is required

in order to prevent the tool completing a

full revolution.

Figure 30, Screenshot of Autodesk Inventor showing the profile of Fig.29being manipulated with the sweep tool( J AMES CLARK )

Figure 31, Screenshot of Autodesk Inventor showing the profile of Fig.30being manipulated with the revolvetool ( J AMES CLARK )


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The next step involves the loft tool, this

command is in two stages, the first is to

use the profile created in the previous

step as the starting point. (Figure 32)

From this profile a working plane is

projected to the specified distance

and a sketch of the required

geometry created for the loft to

connect to. (Figure 33)

Figure 32, Screenshot of Autodesk Inventor

showing the profilethat will be the start for the loft ( J AMES CLARK )


showing the sketch tobe lofted to. ( J AMESCLARK )


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showing the profile to

start for the loft ( J AMES CLARK )

35, Screenshot of Autodesk Inventor showing the profileto finish loft ( J AMESCLARK )

The next step is a loft which is created

in the same way as the previous by

using the profile from the last

command and a sketch that has

been created on a projected plane

with the desired geometry. (Figure 34,

35)


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To create the ball that inserts to the hip joint, the outline

of the ball is sketched onto the Z plane that is central to

the model, (Figure 36) the outline is then halved with

the line kept to be used as an axes for the revolve tool.

The model is finished with a loft of the bottom profile

to a projected plane below it; the projected plane

has a point sketched on it for the profile to be lofted

to. (Figure 37) This creates the pointed end that is

inserted into the hollowed leg bone of the implant

patient.

Figure 36, Screenshot of Autodesk Inventor showing the profile of theball ready to be revolved.( J AMES CLARK )

Figure 37, Screenshot of Autodesk Inventor showingthe point to be lofted to.( J AMES CLARK )


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Finished Model 2

Figure 38, Screenshot of Autodesk Inventor showing the finished Ramosmodel ( J AMES CLARK )


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CONCLUS ION

Now that the models have been completed the author feels the aims and

purposes of the report have been achieved.

Research was carried out of rapid prototyping, hip implants and an

explanation of 3d modelling systems through medical technology was given.

An explanation of the software used to create the finished models was given.

Models were constructed giving an explanation on how complex shapes

were formed with images matching the explanations.

The author is pleased with the quality and outcome of the final report, the

report did not run as was planned due to bad time management from the

author,

The author has gained a greater understanding of rapid prototyping and its

applications while researching for this report and a new interest in the


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medical rapid prototyping industry. He has also realised the importance in

time management of any project.

REFERENCES

HTTPWWW .DESKTOP -3DPRINTERS .COM 3D-PRINTING -EXPLAINED 7

HTTP :// WWW .ZCORPORATION .COM /EN /HOME .ASPX 8

HTTP :// WWW .MAE .CORNELL .EDU /PEOPLE /PROFILE .CFM ? NETID =HBV 1

HTTP :// ENGG .HKU .HK /MONG /AVOELCKER .HTML 9

HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS _2. HTM 10

HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS _2. HTM 11

J MED J 2008; J UNE : VOL . 42(2) HTTP : DAR . J U.EDU . J O J M J 12

J MED J 2008; J UNE : VOL . 42(2) HTTP : DAR . J U.EDU . J O J M J 13

HTTP :// RHEUMATOLOGY .OXFORD J OURNALS .ORG /CONTENT /41/7/824. FULL 14

HTTP :// WWW .HIPIMPLANTATTORNEYS .COM /H IPIMPLANTS .HTML

HTTP :// RHEUMATOLOGY .OXFORD J OURNALS .ORG /CONTENT /41/7/824. FULL 15

HTTP :// WWW .CUSTOMPARTNET .COM /WU /IMAGES /R PROTOTYPING /SLA .PNG /28/11/2011 16

HTTP :// EN .WIKIPEDIA .ORG /WIKI /S ELECTIVE _ LASER _ SINTERING 17

HTTP :// WWW .MATERIALISE .COM /FUSED -DEPOSITION -MODELLING 18


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HTTP :// WWW .EETIMES .COM /DESIGN /INDUSTRIAL -CONTROL /4013703/R APID -PROTOTYPES -MOVE -

TO -METAL -COMPONENTS 19

J OURNAL OF MANUFACTURING SYSTEMS VOL . 21/W O.6 2002 21

REPRINTS @ EMERALDINSIGHT .COM 22

Pro/Engineer user interface ( PTC. COM ) 23

Autodesk Inventor User interface ( Desk Eng .com ) 24

WWW .EMERALDINSIGHT .COM /REPRINTS 25


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TABLES

TABLE 1, CHARLES W. HULL PATENT STEREOLITHOGRAPHY ON MARCH 11 TH 1986

HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS 2. HTM ................................................................... 10

TABLE 2, CARL R. DECKARD S PATENT FOR SELECTIVE LASER SINTERING IN 1989

HTTP :// WWW .ADDITIVE 3D.COM /MUSEUM /MUS 2. HTM ........................................................... 11


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FI GURES

F IGURE 1, IMAGE SHOWS THE PROCESS FROM CAD TO PRINTER TO PROTOTYPE ................................. 7

F IGURE 2, IMAGE OF 3D PRINTER HTTP :// WWW .ZCORPORATION .COM /EN /HOME .ASPX ..................... 8

F IGURE 3, IMAGE OF AN ARTHRITIC HIP ............................................................................................ 12

F IGURE 4, IMAGE SHOWS THE STAGES OF A TOTAL HIP REPLACEMENT .............................................. 12

F IGURE 5, IMAGE SHOWING HOW THE IMPLANT IS FITTED . ................................................................ 13

F IGURE 6, IMAGE OF SIR J OHN CHARNLEY

HTTP :// RHEUMATOLOGY .OXFORD J OURNALS .ORG /CONTENT /41/7/824. FULL ........................ 14

F IGURE 7, IMAGE SHOWING THE PROCESS OF STEREOLITHOGRAPHY ................................................. 16

F IGURE 8, IMAGE SHOWING SLS METHOD

HTTP :// WWW .ARPTECH .COM .AU /SERVICES /SLSDIAG .GIF /28/11/2011 ................................... 17

F IGURE 9, IMAGE SHOWING THE FDM METHOD HTTP :// WWW .MATERIALISE .COM /FUSED -

DEPOSITION -MODELLING ....................................................................................................... 18

F IGURE 10, IMAGE SHOWING THE EBM METHOD

HTTP :// EN .WIKIPEDIA .ORG /WIKI /E LECTRON _B EAM _M ELTING ............................................. 19

F IGURE 11, IMAGE SHOWS THE SGC METHOD .................................................................................. 20

F IGURE 13, GEOMETRY ASSESSED WITH THE USE OF TOUCH PROBE SCANNER ................................... 22

F IGURE 12, GEOMETRY ASSESSED WITH THE USE OF TOUCH PROBE SCANNER ................................... 22

F IGURE 14, SCREENSHOT OF PRO/E NGINEER USER INTERFACE (PTC. COM ) ...................................... 23

F IGURE 15, AUTODESK I NVENTOR USER INTERFACE (D ESK E NG .COM )............................................ 24

F IGURE 16, IMAGE SHOWS A CAD MODEL AND THE MASTER MOULD THAT IS PRODUCED FROM IT .... 25

F IGURE 17, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE LOFT TOOL PRODUCING THE FIRST

PART OF THE MODEL (J AMES CLARK ) ...................................................................................... 27

F IGURE 18, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE LOFT BETWEEN 2 PLANES (J AMES

CLARK ) ................................................................................................................................... 28


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F IGURE 19, SCREENSHOT OF AUTODESK I NVENTOR SHOWING EXTRUDE COMMAND (J AMES CLARK )

............................................................................................................................................... 28

F IGURE 20, SCREENSHOT OF AUTODESK I NVENTOR SHOWING REVOLVE COMMAND (J AMES CLARK )

............................................................................................................................................... 29

F IGURE 21, SCREENSHOT OF AUTODESK I NVENTOR SHOWING EXTRUDE COMMAND (J AMES CLARK )

............................................................................................................................................... 29

F IGURE 22, SCREENSHOT OF AUTODESK I NVENTOR SHOWING R OTATE COMMAND (J AMES CLARK ). 29

F IGURE 23, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE LOFT COMMAND (J AMES CLARK )

............................................................................................................................................... 30

F IGURE 24, SCREENSHOT OF AUTODESK I NVENTOR SHOWING R OTATE COMMAND (J AMES CLARK ) 30

F IGURE 25, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE LOFT COMMAND (J AMES CLARK )

............................................................................................................................................... 30

F IGURE 26, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE FINISHED MODEL (J AMES CLARK )

............................................................................................................................................... 31

F IGURE 27, IMAGE OF CUSTOM IMPLANTS FROM : .............................................................................. 32

F IGURE 28, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE BASIC GEOMETRY OF THE LOWER

SHAFT OF THE MODEL (J AMES CLARK ) .................................................................................... 33

F IGURE 29, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE BASIC GEOMETRY BEING

MANIPULATED WITH THE SWEEP TOOL (J AMES CLARK ) ........................................................... 33

F IGURE 30, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE OF FIG.29 BEING

MANIPULATED WITH THE SWEEP TOOL (J AMES CLARK ) ........................................................... 34

F IGURE 31, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE OF FIG.30 BEING

MANIPULATED WITH THE REVOLVE TOOL (J AMES CLARK ) ...................................................... 34

F IGURE 32, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE THAT WILL BE THE START

FOR THE LOFT (J AMES CLARK ) .............................................................................................. 35


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F IGURE 33, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE SKETCH TO BE LOFTED TO . (J AMES

CLARK ) ................................................................................................................................... 35

F IGURE 34, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE TO START FOR THE LOFT

(J AMES CLARK ) ...................................................................................................................... 36

35, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE TO FINISH LOFT (J AMES CLARK ) 36

F IGURE 36, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE PROFILE OF THE BALL READY TO BE

REVOLVED . (J AMES CLARK ) .. ................................................................................................. 37

F IGURE 37, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE POINT TO BE LOFTED TO . (J AMES

CLARK ) ................................................................................................................................... 37

F IGURE 38, SCREENSHOT OF AUTODESK I NVENTOR SHOWING THE FINISHED R AMOS MODEL (J AMES

CLARK ) ................................................................................................................................... 38

Independent Study Module1

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