Development and Application of Multi‐Scale Numerical Tool to Modeling Pneumatic Ventricular Assist Devices with Increased Athrombogenicity

Abstract

The multi-scale numerical model of blood chamber of ventricular assist device (VAD) with deposited a biocompatible titanium nitride (TiN) nano-coating is introduced. The model is developed to optimize shape parameters of the blood chamber and to determine fracture parameters of the nano-coating. The development of finite element (FE) macro-model is combined with a digital image correlation data to validate a computed strain state. Contrary, on a micro-scale calibration and validation of a representative volume element (RVE) model of the wall of VAD composed of the TiN coating and substrate-polymer is realized by comparison with results of an experimental in situ SEM's micro-tensile test. The multi-scale model of VAD is enriched with materials research. Thus, tensile tests of VADs' polymers are performed to obtain the properties of designed materials of the VADs. On the other hand, on a micro-scale, the properties of TiN are identified based on a nanoindentation test and an inverse analysis for its interpretation. The profilometric studies and analytical model are presented to calculate a residual stress in the TiN. The final result of the paper is the multi-scale numerical tool to modeling pneumatic VADs with increased biocompatibility produced in Poland. REVIEW Fig. 2. The general conception of the multiÀscale model of VAD's blood chamber: (a) a residual stress modeling and (b) an active load modeling. Reproduced with permission. [15] Fig. 7. The distribution of displacement in Z direction on an external surface of the blood chamber of the VAD under pressure 37.3 kPa and in temperature 37 C: (a) the DIC's result, mm, (b) the FE model's result in the VADFEM code, mm, (c) standard deviation of the DIC's ZÀdirectional displacement (in mm), and (d) standard deviation of the DIC's XÀdirectional principal strains (shown values × 10 − 3 ). Reproduced with permission. [33] 285 REVIEW Fig. 9. Local distributions of (a) an effective strain and (b) a triaxiality factor in the model 4 of prototype of the Polish VAD. Reproduced with permission. [17] The AFM's image of topography of the TiN nano-coating of thickness 50 nm on the selected line of the area 100 nm  100 nm; (b) the AFM's image of topography of the TiN nano-coating of thickness 100 nm on the selected line of the area 1 mm  1 mm.

Wearable and Implantable Devices for Cardiovascular Healthcare: from Monitoring to Therapy Based on Flexible and Stretchable Electronics

“…Heart failure is a life‐threatening chronic condition in which the heart muscle fails to circulate blood. Treatment options for end‐stage heart failure include heart transplantation and left ventricular assist devices (LVADs) . In terms of long‐term survival and quality of life, heart transplantation is thought to be the best option.…”

Qualitative and quantitative interpretation of SEM image using digital image processing

“…TiN and Au coatings were deposited on the Bionate II substrates by using a pulsed Nd:YAG laser system (PLD) and parameters of the PLD process were proposed at the AGH University of Science and Technology in Poland. The samples tested in microtension test (Kopernik, ), microshear test (Kopernik et al ., ) and hydrodynamic fatigue tests (Kopernik et al ., ) were analysed using the scanning electron microscopes Hitachi 3500‐N and FEI Nova NanoSEM 450, Hitachi, Tokyo, Japan FEI, Hillsboro, Oregon, USA.…”