Shape transformable bifurcated stents

Abstract

Non-invasive delivery of artificial implants, stents or devices in patients is vital for rapid and successful recovery. Unfortunately, because the delivery passage is often narrower than the size of the delivered object, a compromise between the shape that is effective at the targeted location and a thin form that allows smooth unobstructed travel to the destination is needed. We address this problem through two key technologies: 3D printing and shape memory polymers (SMPs). 3D printing can produce patient-customizable objects, and SMPs can change their initially formed shape to the final desired shape through external stimulation. Using these two technologies, we examine the design and fabrication of bifurcated stents. This study presents a mock-up where blood vessels are fabricated using moulded silicon, which supports the effectiveness of the proposed method. The experimental results reveal that a bifurcated stent with a kirigami structure can smoothly travel inside a vessel without being obstructed by branched parts. We believe that this work can improve the success rate of stent insertion operations in medicine.

Effect of Moisture on Shape Memory Polyurethane Polymers for Extrusion-Based Additive Manufacturing

“…It is important to understand the effects of moisture in these materials for EBAM in order to obtain void-less consistent printing quality and predict engineering part performance. Some of the most promising applications of EBAM-based SMPU are biomedical applications such as customized airflow and 3D-printed cardiovascular stents (Figure 1a), casts and splints [1,2,3]. Other critical and promising applications include grippers, actuators for soft robotics [4], origami-based self-assembly structures for smart manufacturing [5,6] and potential printing of smart self-deployable sports equipment such as a shape memory polymer (SMP) 3D-printed kayak [7].…”

Tighter constraints of multiqubit entanglement in terms of Rényi-α entropy*

“…1. In other words, our new monogamy inequality is indeed tighter than the previous one given in [29]. Under certain conditions, the inequality (9) can even be improved further to become a much tighter inequality.…”

“…Since ω H ( j) ≤ j, for 0 ≤ µ ≤ 1 we obtain FIG. 2: Rényi-α entanglement y with respect to µ: the solid line is for y3 and the dashed line for y4 from the result in [29].…”

Shape Memory Polyurethane and its Composites for Various Applications

“…A key advantage of 3D printing technique is that one can customize the design of object based on patient requirement. Kim and Lee [93] presented a novel design of bifurcated stent through the use of kirigami structures fabricated using 3D printing of SMP. The design of bifurcated stent on the basis of kirigami structure supports to produce transformable 'Y' shape from compactly folded initial shape and helps in smooth travel inside branched vein [94][95][96].…”

“…Sci. 2019, 9, x FOR PEER REVIEW 22 of Development of bifurcated design of tubular stent and its deployment[93].…”