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The robot-assisted catheter system can increase operating distance thus preventing the exposure radiation of the surgeon to X-ray for endovascular catheterization. However, few designs have considered the collision protection between the catheter tip and the vessel wall. This paper presents a novel catheter operating system based on tissue protection to prevent vessel puncture caused by collision. The integrated haptic interface not only allows the operator to feel the real force feedback, but also combines with the newly proposed collision protection mechanism (CPM) to mitigate the collision trauma. The CPM can release the catheter quickly when the measured force exceeds a certain threshold, so as to avoid the vessel puncture. A significant advantage is that the proposed mechanism can adjust the protection threshold in real time by the current according to the actual characteristics of the blood vessel. To verify the effectiveness of the tissue protection by the system, the evaluation experiments in vitro were carried out. The results show that the further collision damage can be effectively prevented by the CPM, which implies the realization of relative safe catheterization. This research provides some insights into the functional improvements of safe and reliable robot-assisted catheter systems.

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The interest of this article lies in the proposition of develop the relationship of the adding of Rice Husk (RH) and acoustic characteristic parameters of Polyurethane (PU) foam. In this article, different amount of RH (2%, 5%, and 8%) was employed into the formation of PU foam system. A rapid method based on professional acoustic measurement was used to determine the acoustic characteristic parameters of the PU foam and PU‐RH composites, such as porosity, flow resistance, tortuosity, and characteristic constants, and analyze the effect of RH on the acoustic characteristic parameters. The measured results indicated that the sound absorption coefficients of PU‐RH composites increased at low frequency along with a small decrease at high frequency on the addition of RH. And adding more RH will be helpful to improve the low‐frequency sound absorption performance of PU foam without increasing the thickness. With the increase of RH additive amount, the flow resistance decreased first and then increased, while the porosity declined slowly generally. Overall, the PU‐RH composite containing 5% RH showed the most satisfactory absorption performance. POLYM. COMPOS., 40:2653–2661, 2019. © 2018 Society of Plastics Engineers

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