Screening of the factors influencing frictional interactions between a cylindrical tip and the cardiac wall using factorial analysis

Methods for Evaluating Friction between Intravascular Device and Vascular Biomodel

“…None ("hard" friction removes whole endothelium and "soft" friction leaves parts intact). Ex vivo Flaction et al [75] Cylinder vs. flattened bovine hearts.…”

“…In order to evaluate the samples shown in Section 2, experiments that simulate physiological conditions should be conducted. Friction includes not only surface force interactions such as interfacial adhesion, asperities deformation, and viscous film shear, but also morphological reaction forces due to surface viscoelastic deformation under the front of the slider [75]. In any case, it is necessary to adopt clinical situations that often occur or that cause problems (e.g., injure living tissues).…”

“…Flaction et al [75] reported that the applied normal force is the dominant factor that affects the frictional force, as determined through experiments that use a cylindrical tip and bovine hearts. They also reported that when a normal force is applied, the areas of contact between the cylinder and the tissue play an important role [75]. The frictional resistance between the guidewire and a vascular wall is also affected by the contact time [97].…”

“…Therefore, some samples should be hydrated with aqueous solution prior to testing [19,28,83]. When blood is used, heparin can be added to avoid coagulation [75]. Note that the lubricating effect of plasma [17] can reduce the frictional force.…”