In electrowetting-on-dielectric (EWOD) microfluidics, a motion of a fluid is created by a voltage applied to the fluid/surface interface. Water and aqueous solutions are the most frequently used fluids in EWOD devices. In order for EWOD microfluidics to be a versatile platform for various applications, however, movability of different types of fluids other than aqueous solutions should be understood. An electromechanical model using a simple RC circuit has been used to predict the mechanical force exerted on a liquid droplet upon voltage application. In this present study, two important features missed in previous works are addressed. Energy dissipation by contact line friction is considered in the new model as the form of resistor. The phase angle is taken into account in the analysis of the AC circuit. The new electromechanical model and computation results are validated with experimental measurements of forces on two different liquids. The model is then used to explain influences of contact angle hysteresis, surface tension, conductivity, and dielectric constant of fluids to the mechanical force on a liquid droplet.
Minimally invasive surgery (MIS) has changed not only the performance of specific operations but also the more effective strategic approach to all surgeries. Expansion of MIS to more complex surgeries demands further development of new technologies, including robotic surgical systems, navigation, guidance, visualizations, dexterity enhancement, and 3D printing technology. In the cardiovascular domain, 3D printed modeling can play a crucial role in providing improved visualization of the anatomical details and guide precision operations as well as functional evaluation of various congenital and congestive heart conditions. In this work, we propose a novel deep learning-driven tracking method for providing quantitative 3D tracking of mock cardiac interventions on customdesigned 3D printed heart phantoms. In this study, the position of the tip of a catheter is tracked from bi-plane fluoroscopic images. The continuous positioning of the catheter relative to the 3D printed model was co-registered in a single coordinate system using external fiducial markers embedded into the model. Our proposed method has the potential to provide quantitative analysis for training exercises of percutaneous procedures guided by bi-plane fluoroscopy.
Percutaneous interventions for structural heart diseases, such as transcatheter aortic valve replacement (TAVR), transcatheter mitral valve repair (TMVr), or left atrial appendage occlusion (LAAO), are rapidly growing and widely available. [1] According to the reports analyzing National Inpatient Sample (NIS) database, there were 40 005 cases of TAVR, 4195 cases of TMVr, and 7550 cases of LAAO in the United States in 2016. [2] Although these catheter-based interventions for structural heart diseases are generally safe, there are still life-threatening complications (such as aortic perforation, cardiac tamponade, or aortic root puncture) that may originate from a lack of precision in procedural steps. [3] Interventionalists performing these complex procedures should be trained more efficiently and routinely formulate comprehensive procedure planning which help optimize clinical outcomes and minimized healthcare cost burden. [4] Although medical procedures for structural heart diseases have significantly evolved in the last 20 years, most of the interventional cardiologists have learned to refine the procedural techniques on patients following initial brief training. Due to the complexity and variability of the human body, there are limitations to what can realistically be accomplished with the
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