Stent procedures require a range of catheters, each with a different stiffness, to deliver a stent to the site of a lesion. A single catheter with adjustable stiffness is a promising way to simplify stenting procedures. Here we report on an adjustable stiffness tube composed of high melting point polymers for the inner and outer layer and a low melting point polymer in the middle that could be incorporated into an adjustable stiffness catheter. Tube stiffness is controlled by thermal modulation of the low melting point polymer via an embedded heater. Seven tubes were tested and their effective Youngs modulus was calculated. The largest change in modulus within a single tube was from 0.53 to 0.09GPa, or an 83% decrease. Over all tube dimensions tested, we recorded stiffnesses ranging from 1.34 to 0.09GPa after applying current for 300s. In contrast, 2 French and 8 French commercial catheters had effective Youngs moduli of 0.583GPa and 0.513GPa, respectively, demonstrating that the adjustable stiffness tube is a viable candidate for use as an adjustable stiffness catheter.
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