・既存の臨床用磁気カテーテルは、一度に一方向にしか曲がることができず、望ましい器用さを備えていません。手術中に柔軟性と硬さを調整できるカテーテルを試作した。
・試作機は、遠隔磁気航法用に設計されています。カテーテルの先端には小型の磁石が搭載されており、外部磁場によって体内を移動することができる。
・個々のセグメントを選択的に柔らかくしたり硬くしたりすることで、カテーテルはナビゲーション中に体によりよく適応し、必要なときに望ましい湾曲を維持することができます。
<関連情報>
低侵襲手術のための導電性相変化ポリマー製可変剛性磁気カテーテル
A Variable Stiffness Magnetic Catheter Made of a Conductive Phase-Change Polymer for Minimally Invasive Surgery
Yegor Piskarev,Jun Shintake,Christophe Chautems,Jonas Lussi,Quentin Boehler,Bradley J. Nelson,Dario Floreano
First published: 06 February 2022
Abstract:Variable stiffness (VS) is an important feature that significantly enhances the dexterity of magnetic catheters used in minimally invasive surgeries. Existing magnetic catheters with VS consist of sensors, heaters, and tubular structures filled with low melting point alloys, which have a large stiffness change ratio but are toxic to humans. In this paper, a VS magnetic catheter is described for minimally invasive surgery; the catheter is based on a novel variable stiffness thread (VST), which is made of a conductive shape memory polymer (CSMP). The CSMP is nontoxic and simultaneously serves as a heater, a temperature sensor, and a VS substrate. The VST is made through a new scalable fabrication process, which consists of a dipping technique that enables the fabrication of threads with the desired electrical resistance and thickness (with a step size of 70 µm). Selective bending of a multisegmented VST catheter with a diameter of 2.0 mm under an external magnetic field of 20 mT is demonstrated. Compared to existing proof-of-concept VS catheters for cardiac ablation, each integrated VST segment has the lowest wall thickness of 0.75 mm and an outer diameter of 2.0 mm. The segment bends up to 51° and exhibits a stiffness change factor of 21.
