DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART

International Journal of Innovative Research in Advanced Engineering (IJIRAE) ISSN: 2349-2163
Issue 12, Volume 4 (December 2017) www.ijirae.com
_________________________________________________________________________________________________
IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 |
ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35
IJIRAE © 2014- 17, All Rights Reserved Page –22
DESIGN AND FE ANALYSIS OF HEART VALVE FOR
CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART
Pushpashree N*, Manjunatha Babu N.S, Mohan Kumar K
Department of Mechanical Engineering. Dr. T.T.I.T – KGF – 563120. Karnataka State, India
Visvesvaraya Technological University, Belgaum – Karnataka State, India
pushpashreen@gmail.com
Manuscript History
Number: IJIRAE/RS/Vol.04/Issue12/DCAE10086
DOI: 10.26562/IJIRAE.2017.DCAE10086
Received: 22, November 2017
Final Correction: 02, December 2017
Final Accepted: 17, December 2017
Published: December 2017
Citation: Pushpashree, Babu, M. & Kumar, M. (2017). DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE
OF ATRIAL SEPTAL DEFECT IN HEART. IJIRAE::International Journal of Innovative Research in Advanced
Engineering, Volume IV, 22-27. DOI: 10.26562/IJIRAE.2017.DCAE10086
Editor: Dr.A.Arul L.S, Chief Editor, IJIRAE, AM Publications, India
Copyright: ©2017 This is an open access article distributed under the terms of the Creative Commons Attribution
License, Which Permits unrestricted use, distribution, and reproduction in any medium, provided the original author
and source are credited
Abstract – Atrial Septal Defect is a congenital heart disease caused due to failure of closing septal which leads to
hole or opening formation between left atria and right atria. In most of the cases, this type of defect gets cured by
itself in childhood stage day by day before stepping to adult. If in case, the hole or opening between septum
primum and septum secundum does not close before adult stage then this defect become permanent. Smart
material has property to self-expand and self-contract which is special character compared to alloys. Due this
special property it is used in ASD devices. The purpose of this study is to show that NITINOL alloy has better
property than other alloys like titanium and nickel alloy with changes made in dimension of hole design. The
design modification and geometry clean-up of the hole is made in Hypermesh and finite element analysis has been
done using Ansys software for static analysis.
Keywords — Smart Material; AS Defect; Design Modification; Hyper Mesh; Static Analysis; Finite Element;
Analysis;
I. INTRODUCTION
Atrial septal defect is one of the congenital diseases where it is seen in heart with hole or opening in it. It is
considered as one of the congenital cardiac anomalies occurs in adulthood. It is normally found as a defect in the
atrial septum allowing pulmonary venous (veins that transfer oxygenated blood) which returns from the left
atrium to pass directly to the right atrium. Based on the size of the defect and size of the shunt it is seen as one of
the anomalies which leads to arterial hypertension and arrhythmias. Basically defect is formed at the
development stage of embryonic heart. The heart is divided into two sides, separated by a wall which is called as
septum [1]. A hole which is normally observed in the septum between the upper chambers of the heart is called
atrial septal defect. There are two different methods which are used for closing defect.
A. Repair of ASD by Surgical method:
In surgical method, to expose the heart an incision is made and hole is closed by patch work. If the opening is large
then it is closed by sewing a patch and if the hole is small then it is closed by stitches.

_________________________________________________________________________________________________
B. Cardiac Catheterization by placing a Device closure (Valve Design):
The device which is used for closing hole and this process is frequently performed for secundum ASD, depending
on the size of the defect and weight of the person. The fig. 1 and fig. 2 shows the defect enclosed by implanting the
device called Amplatzer Septal Occluder cardiac catheterization method. In this study the hole is closed by
Amplatzer Septal Occluder, since this method is considered has best compared to surgery [2]. The defect is
analysed in ANSYS and simulated the output results for titanium alloy, nickel alloy and Nitinol alloy for old design
dimension and modified new dimension of hole.
Fig. 1 Atrial Septal Defect in Heart Fig. 2 Amplatzer Septal Occluder has ASD device
implanted
II. LITERATURE SURVEY
The defect was observed with many children without any symptoms and if in case they found, then medications is
given. Commonly medications which are necessary and prescribed by the doctors include Digoxin. This helps to
strengthen the heart muscle for pumping the blood more efficiently.
Professor Philipp Bonhoeffer developed an alternative method for replacement of heart halve instead of surgery
(Bonhoeffer et al., 2000) [3]. During the development phases of the current PPVI device, preclinical testing was
performed has simple bench and experiments were done on animal as part of routine. In clinical practice, the
occurred function 20% stent fractures (Nordmeyer et al., 2007) [4]. The discrepancy was found here due to the
fact that the in-vivo loading conditions could not be correctly reproduced with experimental set-ups, where the
applied boundary conditions are simulated but does not match the real situation. Dr. Toumar A.J. and Pang S.D.
created a finite element model which can be considered as the healthy aortic valve. To meet the desired results,
model was analysed with stresses on the valve tissue during the performance of a cardiac cycle. The aortic valve is
considered to be modelled and the analysis can be performed using finite element software like ANSYS [5]. Dr.
Quan Yuan carried out geometrical design and finite element analysis on the bio prosthetic heart valve. By
constructing the parametric models of bio prosthetic heart valves via computer aided design, a series of accurate
dimension parameters are obtained [6]. Prof. Robert D. Howe studied that functionally heart valves complex and
performing surgical repair will be difficult. Simulation based surgical planning could facilitate repair, but current
finite element (FE) studies are prohibitively slow for rapid. The FE model is created to study a repair technique of
generalized aortic valve that incorporates graft material into the native valve. Here the graft has significantly
different mechanical properties compared to native leaflets [7]. After referring some of the medical journals
related to this ASD device about tissue erosion among the patients who are implanted with this device, result was
a serious problem inside the heart due to tissue erosion. If the device dimension is improper then it will create
abrasion against the wall of the heart which leads to create hole / expand the existing hole [8]. FDA (Food and
Drug Administration, U.S) reported that there will be 1 to 3 people approximately face an erosion problem out of
1000 patient. The case study was done on the incidence of erosion within body from day of implant to the seventh
day and then one month, six months and finally at twelve months [9].
During this cardiac catheterization procedure, the person is sedated and a small incision is made at groin region as
shown in fig. 3. And then catheter is inserted into a blood vessel in the groin and gently guided to the inside of the
heart. The catheter is a small thin flexible tube with presence of imaging technique in it. Once the catheter is sent,
the cardiologist passes Amplatzer device at defect region and open ASD to prevent blood from flowing through it
as in fig. 4.

_________________________________________________________________________________________________
Fig. 3 Path way of Catheter through which Amplatzer
is sent
Fig. 4 Valve design for closure of ASD
III. MODELLING AND ANALYSIS
The process involves importing the model IGES file in HYPER MESH 12, then geometry clean-up is performed. In
most of the time the geometry of the mesh size will be different. So in order to get better results it needs to be
meshed for appropriate mesh size. Once the meshing has been done, then assign boundary conditions and
material properties. The material property details are mentioned in table (I), (II) and (III). Now apply the pressure
load on the defect area ranging between 120mm of Hg to 139mm of Hg. Usually a normal human blood pressure
ranges from 15kPa to 20kPa. Hence the pressure considered is higher than the normal range. After preparation of
deck, export cdb file to ANSYS 16.2. Finally perform the static analysis and plot the result in HYPER VIEW. The
steps involved in this process are as follows:
 Import the IGES file in HYPER MESH 12
 Perform geometry clean up
 Mesh the geometry for appropriate mesh size
 Assign the Boundary conditions and material properties
 Apply load on desired face
 After deck preparation export .cdb file to ANSYS 16.2
 Evaluate in ANSYS 16.2 and plot the result in HYPER VIEW.
TABLE I - MATERIAL DETAILS OF NICKEL
S.No Property Value Unit
1 Density 4.5 x 10-9 Tonnes/mm3
2 Tensile strength 220 MPa
3 Young’s Modulus 1.16 x 105 MPa
4 Poisson’s Ratio 0.29 -
TABLE II -MATERIAL DETAILS OF NICKEL
S. No Property Value Unit
TABLE III - MATERIAL DETAILS OF NITINOL
Sl. No Property Value Unit
TABLE IV- MATERIAL DETAILS OF HEART
S. No Property Value Unit
3 Young’s Modulus 1000 MPa
Finite Element analysis is a method that helps to simulate mechanical parts and systems to get information about
failure, deformation and stresses under various kind of loadings. When a linear static analysis is carried out we
can determine the stresses, strains, displacements and the reaction forces under any application of loads and
boundary conditions. Always it is seen that when we are carrying out linear analysis it will make two assumptions
as below:
 Behaviour of structure is Linear (Obeys Hooke's Law)
 Loads are static

_________________________________________________________________________________________________
IV. RESULTS
Finite element analysis was carried out for different valve design and material considerations. Here analysis is
done for two different hole dimensions to figure out which material yields the better results [10]. After completing
the analysis, simulate the results for titanium alloy, nickel alloy and NITINOL for yield stress and factor of safety.
The table V helps us to compare the results of stress and deformation obtained for the individual materials.
The two different defect dimensions considered as follows,
 Initially consider hole diameter has 11mm and simulate FE analysis for Titanium alloy, Nickel alloy and
Nitinol.
 Now change the dimension to 6.4mm and again perform the analysis for Ti alloy, Ni alloy and NITINOL.
A. Counter results plots for Titanium alloy with 2 different hole dimension:
Plot the results for deformation and yield stress as done for the initial dimension and modified hole dimension.
Please add material property details for titanium alloy then simulate the results. Here Max. Stress = 310MPa >
220MPa from fig. 11.
1) Initial Design:
Fig. 6 Deformation Plot for initial valve design Fig. 7 Maximum stress plot in initial valve design
2) New modified Design:
Fig. 8 Deformation Plot for Modified valve design Fig. 9 Maximum stress plot in modified valve design
B. Counter results plots for Nickel alloy with 2 different hole dimension:
Repeat the same procedure has done for the previous material to plot the results for initial and modified
dimension. Here Max. Stress = 223MPa > 220MPa from fig. 13.
1) Initial Design:
Fig. 10 Deformation Plot for initial valve design Fig. 11 Maximum stress plot in initial valve design

_________________________________________________________________________________________________
Fig. 12 Deformation Plot for Modified valve design Fig. 13 Maximum stress Plot in Modified Valve design
C. Contour plots for Nitinol alloy with 2 different hole dimension:
Now plot results for final material which has considered has a smart material called NITINOL. Follow the same
steps as followed to simulate results in ANSYS for initial and modified hole dimension. Here Max. Stress = 179MPa
< 320MPa from fig. 17.
1) Initial Design:
Fig. 14 Deformation Plot for Initial valve design Fig. 15 Maximum stress Plot in Modified Valve design
Fig. 16 Deformation Plot for Modified valve design Fig. 17 Maximum stress Plot in Modified Valve

_________________________________________________________________________________________________
TABLE V - COMPARISON OF SIMULATION RESULTS
Sl No Valve material Initial Design Final Design
Yield Stress
(MPa)
Factor of Safety
(Initial Design) (Final Design)
1 Titanium 310 223 220 0.71 0.99
2 Nickel 268 179 320 1.19 1.79
3 Nitinol 139 57 450 3.24 7.89
From the above finite element analysis by comparing the simulated results, it can concluded that NITINOL yields
better result compared to Titanium and Nickel alloy. Hence, NITINOL can be used in Amplatzer Septal Occluder
for closing Atrial Septal Defect.
V. CONCLUSIONS
Design of aortic valve and Finite Element Analysis (FEA) is performed on the valve. The aim of this study was to
model a percutaneous valve and perform the finite element analysis. The design process was carried out to meet
the functional and placing the valve in the premises of hole area. Finite element analysis and simulation of the
model helped in optimizing the selection of exact valve design and the suitable material which enabled to have
long term durability, low thrombogenicity, resistance to migration and paravalvular leak. After comparing the
simulated results of titanium alloy, nickel alloy and NITINOL alloy, “Nitinol alloy was considered as the best
material to use in Amplatzer Septal Occluder device for closing Atrial Septal Defect in heart”.
REFERENCES
1. Adiele, D. K., Chinawa, J. M., Arodiwe, I. O., Gouthami, V., Murthy, K. S., Eze, J. C., … Ujunwa, F. A. (2014). Atrial
septal defects: Pattern, clinical profile, surgical techniques and outcome at Innova heart hospital: A 4-year
review. Nigerian Medical Journal : Journal of the Nigeria Medical Association, 55(2), 126–129.
https://doi.org/10.4103/0300-1652.129642
2. Du ZD, Hijazi ZM, Kleinman CS, Silverman NH, Larntz K; Amplatzer Investigators. Comparison between
transcatheter and surgical closure of secundum atrial septal defect in children and adults: results of a
multicenter nonrandomized trial. J Am Coll Cardiol 2002;39(11):1836–44.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3461693/
3. Bonhoeffer P., et al. Percutaneous replacement of pulmonary valve in a right-ventricle to pulmonary-artery
prosthetic conduit with valve dysfunction. Lancet. 2000;356:1403–1405.
https://www.ncbi.nlm.nih.gov/pubmed/11052583
4. Nordmeyer, Risk stratification, systematic classification and anticipatory management strategies for stent
fracture after percutaneous pulmonary valve implantation. Circulation, Vol.115, No.11 (20 March 2007),
pp.1392-1397.
https://doi.org/10.1161/CIRCULATIONAHA.106.674259
5. Toumar AJ, Pang SD. Stress Analysis of the Aortic Valve Using Finite Element Modelling Software.
https://www.esp.nus.edu.sg/undergraduate/UROP%20Projects/2008-Alex_Tourmar.pdf
6. Yuan, Quan (2007) - Geometrical design and finite element analysis on the bio prosthetic heart valve. Journal of
Clinical Rehabilitative Tissue Engineering Research. 11. 3480-3483.
https://www.researchgate.net/publication/287852967
7. Peter E. Hammer, Michael S. Sacks, Pedro J. del Nido and Robert D. Howe – Mass-Spring Model for Simulation of
Heart Valve Tissue Mechanical Behaviour. Annals of Biomedical Engineering June 2011, Volume 39, Issue 6, pp
1668–1679 https://doi.org/10.1007/s10439-011-0278-5
8. Thomson, J. D. R., & Qureshi, S. A. (2015). Device closure of secundum atrial septal defect’s and the risk of
cardiac erosion. Echo Research and Practice, 2(4), R73–R78. http://doi.org/10.1530/ERP-15-0023
9. U.S. FDA. FDA Executive Summary Memorandum – May 24, 2012: Circulatory System Advisory Panel Meeting –
Transcatheter ASD Occluders: Clinical Update and Review of Events [pdf]. May 24, 2012. (available at:
http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdv
isoryCommittee/CirculatorySystemDevicesPanel/ucm300073.htm )
10.Kumar, G. and Mathew, L. (2009) Finite element analysis of a percutaneous aortic valve stent design. Health, 1,
2-7. doi: 10.4236/health.2009.11002.

DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART

Similar to DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART (20)

More from AM Publications

More from AM Publications (20)

Recently uploaded

Recently uploaded (20)

DESIGN AND FE ANALYSIS OF HEART VALVE FOR CLOSURE OF ATRIAL SEPTAL DEFECT IN HEART