www.grantadesign.com

Materials Selection Methods and Information

Databases for Design of Optimised Medical

Devices

Dr Sarah Egan

Introduction to Granta

Company overview

Brief history

Rational Materials Selection

Principles of rational materials selection

Case study:

Advanced Information for Medical Device Design

Biological response to synthetic materials

Biomechanics of human tissues

Information databases in action

Outline

Company overview

Brief history

Introduction to Granta

The materials information technology experts

Selected customers

Aermacchi

Airbus

ASCO Industries

Baker Hughes

Baxter Healthcare

Boeing

Bombardier Aerospace

Bosch

Carrier

Centro Ricerche Fiat

Chengdu Aircraft

Cochlear

Constellium

Covidien

DePuy

Deutsches Zentrum fr Luft- & Raumfahrt

EADS Astrium

ESA

Eurocopter

GE - Aviation & GE - Energy

Honeywell Aerospace

Ishikawajima-Harima Heavy Industries

JLR

Lab 126 (Kindle)

LL Products

Lockheed Martin

MASCO

MBDA Group

MTU

NASA

Northrop Grumman

Novo Nordisk

Owens Corning

Parker Aerospace

Perkins Engines

Philips Technologie

Raytheon

Rheinmetall (KSPG Automotive)

Rhodia

Rolls-Royce

RUAG Space

Suzlon

Sulzer

Toshiba Corporation

The Timken Company

Thyssen Krupp Steels

TRW Automotive

Vestas

Whirlpool

The Granta team

The worlds largest concentration of materials

information technology expertise

110 engineers, scientists, developers, support staff

Locations & service partners in US, Europe, A/P

Providing software, data products, services

Consistent growth with profitability

Customers: many of the worlds leading

engineering enterprises

Grantakey facts

Cambridge team, July 2010

Granta for industry

Materials &

Processes

Materials

decision

support

Eco design &

environmental

regulations

Materials

information

management

Materials

support for

CAD, CAE

http://www.simulia.com/http://www.ugs.com/

Grantas CES EduPack is used to support

teaching of materials & processes at 800

universities and colleges worldwide

Granta for education

The next generation of

engineers is familiar with

Granta and its technology

Materials Education Symposium, April 2011

Granta Designinnovating since 1994

1994: Granta Design is founded; key

UIPs:

Extensive materials data compilation

Materials property charts (Ashby

charts)

Performance index concept

1st Product: Cambridge Material

Selector

1995-7: Development and refinement of materials data compilation using first

implementations of Grantas unique data checking and estimation techniques

1998: 1st release of Cambridge Process Selector

1999: CES Selector launched 1st integrated material and process selector

2000: Strategic investment by ASM International, Granta now extends

expertise to management and publication of materials data

2001: Granta provides digital online version of MIL-HDBK 5

Granta Designinnovating since 1994

2002: Launch of MDMC by Granta, ASM, NASA.

New tools for plastics selection

2004: First release of GRANTA MI, later to become industry standard for

corporate materials information management

2005: New CES Edupak, building on materials data and selection tools with

content, tailored databases and resources for teaching

2006: Materials Strategy Consortium starts focus on cost optimisation

2007: New Materials for Medical Devices database

2008: Eurocopter hosts first meeting of new Environmental Materials

Information Technology (EMIT) consortium

2010: Granta opens new headquarters at Rustat House and expands team to

80 people

2011: First overseas offices (in US & Germany)

Collaboration with Autodesk to deliver a new eco design tool

New software for coatings and composite data management.

Granta Designinnovating since 1994

Principles of rational selection

Case Study: Medical Forceps

Rational Material Selection

Conventional approaches:

Use previous material, use a familiar material

Ask materials vendor

Ask colleague or consultant

Unstructured database/Web search

Rational Selection methodology:

Rational materials selection:

Exhaustive

Systematic

Auditable

Requirements:

Complete & comparable dataset for all materials

Use of Performance indices (e.g. cost per unit of stiffness)

Design Requirements

Optimal material for application All materials

5 obstacles to rational materials selection:

Lack of a rational, systematic method

Lack of relevant data

Non-comparable data

Holes in the data

Lack of information on material price

Why is it difficult?

Exhaustive

Systematic

Auditable

CES Selector

Material selection for a new product

Replacement of a material in an existing product

Evaluation of materials recommended by a vendor

Expert PC-based tool for material users and producers

that aids critical design & business decisions:

Key components

Rational Selection methodology

Data on materials & processes

Visualization & selection tools

Prediction & evaluation tools

Rational selection methodology - Ashby

All Materials

Breakdown design requirements into:

Function What does the component do?

Constraints What essential conditions must be met?

Objectives What is to be maximized or minimized?

Screen on constraints - Go / no-go criteria (usually many)

Rank on objectives - Ordering of materials that go

Supporting information Specialist databases, contact suppliers

Local conditions Preferred suppliers, process capability, location

Top Candidate Materials

Final Selection

Ranking - Performance Index Finder

Key component of Rational Selection methodology

Identifies & plots Performance index

Covers main standard load cases

(mechanical, thermal, electrical, vapour barrier)

Optimize: mass, volume, cost, eco footprint...

Trade-off multiple objectives

Mass per

unit of stiffness

Mass vs cost

trade-off

Example of resulting Ashby chart L

ow

er

Co

st

Lower Permeability

Case study: Medical forceps handle

Function:

Handle of minimally-invasive electrosurgical forceps

Constraints:

Biocompatibility USP class VI or ISO 10993

Sterilizability (steam autoclave) Good or Excellent

Mechanical Stiffness & strength in bending

Mechanical toughness Impact Strength >7 kJ/m^2

Electrical Insulator

Dimensional stability Water absorption @ 24hr < 0.5%

Processing 3D complex shape; surface finish

Objectives:

Minimize cost

Minimize volume (component size)

Beam loaded in bending

Stiffness-limited design

Length, section shape specified

Section area free Current material:

PEEK (unfilled)

Biological response to synthetic materials

Biomechanics of human tissues

Information databases in action

Advanced Information for

Medical Device Design

Information needs:

1. Properties of materials used to make devices

2. Properties of surrounding tissues:

Biological response

Mechanical properties

Materials in medical device design

Information needs:

1. Properties of materials used to make devices

2. Properties of surrounding tissues:

Biological response

Mechanical properties

Materials in medical device design

Medical Materials Database

Cardiovascular module

Orthopaedic module

In addition to mechanical/physical properties, information is

needed on:

Chemical and biological properties

Regulatory classifications

Compatibility of materials, surface treatments, coatings and drugs

Predicate devices

Historically, this information has been:

Complex and poorly structured

Sometimes of questionable quality

Widely dispersed (literature, books, suppliers, FDA, patents)

Time-consuming to find and compile

Information gap between engineers and medical personnel

Engineers often do not understand the biology and vice-versa

Medical materials information needs

An information resource & associated tools providing:

Engineering properties

AND biological response

AND coating and drug compatibility information

Application information

where materials are used in predicate devices

Covering materials used in:

Cardiovascular implantable devices, plus catheters

Orthopaedic implantable devices and trauma

Developed in conjunction with:

Guidance committee

Peer review panel

What is the Medical Materials database?

DEMONSTRATION

Information needs:

1. Properties of materials used to make device

2. Properties of surrounding tissues:

Biological response

Mechanical properties

Materials in medical device design

Human Biological Materials

Textbooks

Quickly find simple data

Limited detail concerning age, direction dependencies

Journal articles

Wide range of articles covering different tissues, testing methods,

dependencies etc.

Time consuming do exhaustive search

Difficult to analyse effects of different tissues, testing methods etc.

Animal tissue testing

Not human tissue

Costly

CT scan data

Dependent on empirical density/property relationships

Person specific

Typical data sources

Material properties of human tissues

Mechanical

Physical

Current coverage: Load bearing bones

Femur

Tibia

Vertebrae

Acetabulum

Age and direction dependence

Export directly to FEA packages

Human Biological Materials

DEMONSTRATION

1. GRANTA MI

Access from company internal servers

Combine with synthetic material databases AND

proprietary data COMPLETE RESOURCE

2. Online

As part of ASM Medical Materials database series

Availability