A Novel Fabrication Method for Compliant Silicone Phantoms of Arterial Geometry for Use in Particle Image Velocimetry of Haemodynamics

Abstract

Cardiovascular diseases (CVDs) are one of the leading causes of death globally. In-vitro measurement of blood flow in compliant arterial phantoms can provide better insight into haemodynamic states and therapeutic procedures. However, current fabrication techniques are not capable of producing thin-walled compliant phantoms of complex shapes. This study presents a new approach for the fabrication of compliant phantoms suitable for optical measurement. Two 1.5× scaled models of the ascending aorta, including the brachiocephalic artery (BCA), were fabricated from silicone elastomer Sylgard-184. The initial phantom used the existing state of the art lost core manufacturing technique with simple end supports, an acrylonitrile butadiene styrene (ABS) additive manufactured male mould and Ebalta-milled female mould. The second phantom was produced with the same method but used more rigid end supports and ABS male and female moulds. The wall thickness consistency and quality of resulting stereoscopic particle image velocimetry (SPIV) were used to verify the fidelity of the phantom for optical measurement and investigation of physiological flow fields. However, the initial phantom had a rough surface that obscured SPIV analysis and had a variable wall thickness (range = 0.815 mm). The second phantom provided clear particle images and had a less variable wall thickness (range = 0.317 mm). The manufacturing method developed is suitable for fast and cost-effective fabrication of different compliant arterial phantom geometries.

Development of Custom Wall-Less Cardiovascular Flow Phantoms with Tissue-Mimicking Gel

“…In general, walled flow phantoms present their own unique set of challenges such as increased difficulty in creating complex geometries and consistent wall thickness along with increased cost. 7 , 40 , 59 Additionally, this study utilized continuous flow whereas pulsatile flow is often desired for cardiovascular flow phantoms. Preliminary experimentation has qualitatively shown realistic mechanical reactions of the gel phantoms in response to pulsatile flow.…”

“…This may be important in using the phantoms for pulsatile flow applications, since compliance is known to be inversely proportional to wall thickness. 59 Further mechanical testing may be warranted, such as tensile testing and dynamic mechanical analysis to elucidate the elastic and viscous responses, with the extension of methods where tension and oscillatory forces become more prevalent. 8 …”

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

“…A greater wall thickness is advantageous for robustness of these models; however, it can be a limiting factor when trying to accurately simulate vessel behavior that is seen clinically. Studies that have utilized fluid–structure interaction (FSI) have reported that rigid wall assumptions can lead to an overestimation of wall shear stress (WSS) in comparison with a compliant phantom ( 27 , 28 ). In addition, wall stiffness is a measure of arterial health, and the pulse waveform can vary in stiff and compliant arteries.…”

Algorithms for determination of the vector velocity field in a two-phase gas-liquid flow

“…Particle Image Velocimetry is currently one of the best tools to determine the vector velocity field. In the industrial practice, the application possibilities of this technique have been widely documented, for example in mechanical engineering [15], process engineering [16], medicine [17], environmental engineering [18] and power industry [19]. The most important problem nowadays is the choice of appropriate measurement setup and its optical and software configuration [14].…”