FEA analysis of silicone MCP implant

Podnos, Evgeny; Becker, Eric B.; Klawitter, J. J.; Strzepa, P.

doi:10.1016/j.jbiomech.2005.03.019

Cited by 23 publications

(15 citation statements)

References 15 publications

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“…As described above, our epicardial micropacemaker flexible lead is a short open-coil design that is intended to avoid stress-risers that occur when conventional polymeric encapsulants become embrittled and fracture [12, 13, 4, 14]. The dimensions of the wire and coil that formed our prototype open-coil lead were chosen by intuition rather than engineering analysis of the composite material that arises when the spring-like coil is embedded in elastic connective tissue.…”

Section: Discussionmentioning

confidence: 99%

Analytical Modeling for Computing Lead Stress in a Novel Epicardial Micropacemaker

Zhou

Bar‐Cohen

Peck

et al. 2017

Cardiovasc Eng Tech

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Purposes Implantation and maintenance of a permanent cardiac pacing system in children remains challenging due to small patient size, congenital heart defects and somatic growth. We are developing a novel epicardial micropacemaker for children that can be implanted on the epicardium within the pericardial space via a minimally–invasive technique. The key design configurations include a novel open-coiled lead in which living tissue replaces the usual polymeric support for the coiled conductor. To better understand and be able to predict the behavior of the implanted lead, we performed a radiographic image-based modeling study on a chronic animal test. Methods We report a pilot study in which two mechanical dummy pacemakers with epicardial leads were implanted into an adult pig model via a minimally invasive approach. Fluoroscopy was obtained on the animal on Post-Operative Days #9, #35 and #56 (necropsy). We then constructed an analytic model to estimate the in vivo stress conditions on the open-coil lead based on the analysis of orthogonal biplane radiographic images. Results We obtained geometric deformation data of the implanted lead including elongation magnitudes and bending radii from sequenced films of cardiac motion cycles. The lead stress distribution was investigated on each film frame and the point of maximum stress (Mean Stress= 531.4 MPa; Alternating Stress = ± 216.4 MPa) was consistently where one of the leads exited the pericardial space, a deployment that we expected to be unfavorable. Conclusions These results suggest the modeling approach can provide a basis for further design optimization. More animal tests and modeling will be needed to validate whether the novel lead design could meet the requirements to withstand ~200 million cardiac motion cycles over 5 years.

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Section: Discussionmentioning

confidence: 99%

Analytical Modeling for Computing Lead Stress in a Novel Epicardial Micropacemaker

Zhou

Bar‐Cohen

Peck

et al. 2017

Cardiovasc Eng Tech

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“…This could be attributed to the lack of filler content in the silicones, which has been suggested to be a strain amplifier (Rault et al, 2006;Podnos et al, 2006;Mullins & Tobin, 1965). The presence of filler particles in the silicone can significantly restrict the mobility of polymer chains and increase the degree of non-linearity exhibited (Cosgrove et al 1997;Cassagnau & Mélis, 2003).…”

Section: Silicone Behaviourmentioning

confidence: 99%

Development of novel synthetic muscle tissues for sports impact surrogates

Payne

Mitchell

Bibb

et al. 2015

Journal of the Mechanical Behavior of Biomedical Materials

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Impact injuries are commonplace in sport and often lead to performance detriment and debilitation. Personal Protective Equipment (PPE) is prescribed as a mandatory requirement in most sports where these impacts are likely to occur, though the methods of governance and evaluation criteria often do not accurately represent sports specific injury scenarios. One of the key shortcomings of such safety test standards is the human surrogate to which the PPE is affixed; this typically embodies unrepresentative geometries, masses, stiffness and levels of constraint when compared to humans.A key aspect of any human surrogate element is the simulant material used. Most previous sports specific surrogates tend to use off-the-shelf silicone blends to represent all the soft tissue structures within the human limb segment or organ; this approach potentially neglects important human response phenomena caused by the different tissue structures.This study presents an investigation into the use of bespoke additive cure Polydimethysiloxane (PDMS) silicone blends to match the reported mechanical properties of human relaxed and contracted skeletal muscle tissues. The silicone simulants have been tested in uniaxial compression through a range of strain rates and fit with a range of constitutive hyperelastic models (Mooney Rivlin, Ogden and Neo Hookean) and a viscoelastic Prony series.

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“…Other studies have also shown that the properties of some silicones used for this application were sensitive to frequency and temperature in the range 23–37°C 5. Another study concluded that the mechanical properties of silicones do not change appreciably in the temperature range 23–37°C 6. It is important to understand this aspect of silicone elastomers because they are currently used for many designs of artificial finger and wrist joints.…”

Section: Introductionmentioning

confidence: 95%

“…This article presents the frequency‐dependent viscoelastic properties of three medical grade silicone elastomers. There have been many experimental1–9 and theoretical10–14 studies on the viscoelastic properties of elastomers and polymers. However, it is not clear from the literature how the viscoelastic properties of silicone elastomers depend on frequency.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of copolymer of aniline and pyrrole by inverted emulsion polymerization method for supercapacitor

Palaniappan

Sydulu

Srinivas

2009

J of Applied Polymer Sci

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Several studies have assessed the association between genetic polymorphisms of DRD2 and DRD4 genes and opioid dependence risk, while the results were inconsistent. We performed a meta‐analysis, including 6,846 opioid dependence cases and 4,187 controls from 22 individual studies, to evaluate the roles of four variants (DRD2 −141ins/delC, rs1799732; DRD2 311 Ser > Cys, rs1801028; DRD2‐related TaqI A, rs1800497 and DRD4 exon III VNTR) in opioid dependence for the first time. We found that the −141delC polymorphism was significantly associated with increased risk of opioid dependence (homozygote comparison: odds ratios [OR], 2.71; 95% confidence interval [CI], 1.74–4.22; dominant comparison: OR, 1.27; 95% CI, 1.09–1.48). Similarly, the TaqI A1 polymorphism was also significantly increased opioid dependence risk (homozygote comparison: OR, 2.06; 95% CI, 1.25–3.42; dominant comparison: OR, 1.34; 95% CI, 1.08–1.67). Moreover, long allele (≥5‐repeat) and 7‐repeat allele of DRD4 exon III VNTR were found to be associated with significantly increased opioid dependence risk (OR, 1.50; 95% CI, 1.24–1.80 and OR, 1.57; 95%, 1.18–2.09, respectively). However, no association was detected between the DRD2 311 Ser > Cys polymorphism and opioid dependence. In conclusion, our results suggested that DRD2 −141ins/delC, DRD2‐related TaqI A and DRD4 exon III VNTR polymorphisms might play important roles in the development of opioid dependence. © 2011 Wiley‐Liss, Inc.

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FEA analysis of silicone MCP implant

Cited by 23 publications

References 15 publications

Analytical Modeling for Computing Lead Stress in a Novel Epicardial Micropacemaker

Analytical Modeling for Computing Lead Stress in a Novel Epicardial Micropacemaker

Development of novel synthetic muscle tissues for sports impact surrogates

Synthesis of copolymer of aniline and pyrrole by inverted emulsion polymerization method for supercapacitor

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