Computational Methods and Advanced Materials

Simulations of Biomedical Devices

FEA of Self-Expanding Braided Wirestent

Geometrical ModelingCardiovascular/Gastroenterical/Pulmonary Device

(i) Creation of a base module

of two crossing wires;

(ii)Extending the base module

with a translated copy;

(iii)Replicating the base

module in both directions

of the base plane;

(iv)Rolling the resultant grid

into a cylinder

Stent deployment

Simulation

Reality

Stent elongation: Stress analysis

3 different materials

Phynox, Nitinol, Stainless Steels

Finite Element Analysis

Filter

diam:4 mm

Filter

diam:6 mm

Filter

diam:8 mm

60% covered

70% covered

80% covered

6 struts

10 struts

Nitinol Embolic Protection Filters: Design Investigation by Computational Tools

Geometrical ModelingCardiovascular Device Finite Element Analysis

Simulation

Experimental validation ���� Filter deployment

µµµµCT scan

XY

Z

Parametric CAD Model

Markers

Struts

Membrane

Model parameters: Filter diameter, Filter length,

Strut diameter, Strut number / distribution,

Strut shape, Marker size, Covering

percentage

µµµµCT scan

Simulation

Filter-vessel interaction ���� Contour-ability

Gap

Nitinol Laser-cut Stents: The Current Trend of Peripheral Stenting

Experimental Tests and Material CharacterizationCardiovascular Device Finite Element Analysis

Crush Tests

Constitutive model implementation:

“user material subroutine”(Abaqus)

Spinal Vertebrae Spacer: A Medical Application of Shape Memory Effect� Device objective: substitution of damaged

intervertebral disc

� Shock absorber & motion unit

� Maintenance of inter-vertebral separation

� No nerve compression

� Spine compression / rebounding during activities

� Gravity resitance on head and trunk during prolonged sitting and standing,

� Spinal segment flexibility, rotation, and bending on side

Ortopaedical Device

Due to symmetry, only ¼ of

the device is simulated

• Device is compressed in martensitic phase, assuming a reduced shape [ to help device insertion ] .Once positioned in body, it recovers original expanded shape by thermal recovery (shape memory effect) and starts to work opposing force to spinal compressive load

• Compare different Ni-Ti spinal spacers during implant and physiological loading

Finite Element Analysis

G. Attanasi A, F. Auricchio A, M. Conti A, S. Morganti A, A. Reali A, U. Stefanelli B

Contact: Prof. F. Auricchio Email: auricchio@unipv.it Tel.: +39 0382985476

A Università Degli Studi di PaviaDipartimento di Meccanica Strutturale

Via Ferrata ,1

C Consiglio Nazionale delle RicercheIstituto di Matematica Applicata e

Tecnologie InformaticheVia Ferrata ,1

B EUCENTREEuropean Centre for Training and Research

in Earthquake EngineeringVia Ferrata ,1