Steerable catheters

Tina Shoa John D. Madden, Nigel R. Munce and Victor X.D. Yang  

A catheter is a thin flexible hollow tube that is inserted into body cavities to provide a channel for fluid passage or an entry for a medical device. Catheters as fluid channel may be used to remove waste fluids from the body or direct a liquid into the body. Practical 

Biomedical Applications of Electroactive Polymer Actuators Edited by Federico Carpi and Elisabeth Smela 2009 John Wiley Sons Ltd. ISBN 978-0-470-77305-5 

Catheters have a long history [1]. The earhest catheters were formed from straw and leaves and were used for drainage of urine. Hollow leaves of plants, coated with lacquer, were used as catheters in China around 100 BC. In 1036 AD Avicenna described the first flexible catheter made from stiffened animal skins. Benjamin Franklin designed a flexible silver catheter in 1752 for patients who suffered from bladder disease. The modem application of the catheter started in 1868 when a catheter with features for controlling the catheter insertion depth was patented by Dr N.B. Somborger. The modem disposable catheter was invented in the 1940s by David S. Sheridan [1]. 

Recent advanced catheter designs exploit active tip bending for more controllable and efficient minimally invasive medical procedures. Important considerations in developing and implementing active bending catheters include the needs for miniaturization, reasonable fabrication costs, safety and the appropriate mechanical properties. These parameters are discussed in more detail in the following section. 

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Additional tools (lasso, catcher, steerable catheters...) n... 

Transfemoral approach with a tip-deflecting wire or steerable catheter in order to catch the lead in the region where the lead is free (in the right atrium if the lead slips through the adher-ences in the innominate vein if the lead does not slip into the adherences) and to make the proximal end intravascular and free floating. It is important to catch the lead as near as possible to the proximal end, where only insulation is present (Fig. 5.11). 

Novel steerable catheter with minimal diameter... 

Mazzoldi, A., and D. De Rossi. 2000. Active polyaniline fibers for a steerable catheter. Proc SPIE-EAPAD 3987 273. 

Mazzoldi, A. and De Rossi, D. (2000). Conductive-polymer-based structures for a steerable catheter, in Y. Bar-Cohen (ed.), Smart Structures and Materials 2000 Electroactive Polymer Actuators and Devices (SPIE - The International Society for Optical Engineering, Bellingham, WA), pp. 273-280. 

Fig. 1.19 Thin (4.1Fr) bipolar active-fixation lead with a fixed screw and no Inmen for a stylet. (Medtronic 3830 SelectSecure ). The screw is coated with beclomethasone. The lead is delivered by a steerable catheter. (Permission for nse Medtronic.)...

Not all active-fixation leads have an extendable-retractable screw. Some models have a fixed screw coated in mannitol which dissolves in blood prior to fixation (Guidant, Sweet Tip ). As discussed previously, a thin diameter cabled lead inserted through a steerable catheter has a fixed screw which is essentially covered by the catheter until it is attached to the endocardium (Medtronic SelectSecure Medtronic Inc., Minneapolis MN) (Fig. 1.19). Active-fixation leads can also be attached to the endocardium using a steerable stylet (St Jude... 

Fig. 4.94 (Above) The select site steerable catheter (model 10634, Medtronic Inc.). PACE 27 892, 2004. (from Mond HG, Grenz D Implantable Transvenous pacing leads The shape of the things to come. PACE 27 892, 2004...

Figure 5.11 Steerable catheter composed of steerable Inner and outer guides. Copyright 2015 Hansen Medical , Inc. All rights reserved. (Used with the permission of...

Alvarez JB, Macnamara p, MiUer T, Reis G, Romo E, Sewell CM, et al. Robotically controlled steerable catheters. March 22, 2012. WO Patent App. PCT/US2011/... 

Ionic Polymer—Metal Composite (IPMC) Based Steerable Catheters... 

IPMC actuators exhibit a typical strain of 0.5 %, strain rate of 3 %/s and a typical stress of 3 MPa. They are actuated at potentials of <10 V [42]. The performance of these actuators has been improved by using various combinations of cations [23-25] and different types of electrodes, such as platinum-copper [26]. In this chapter a brief overview of different designs and test procedures using this type of actuators is presented, as similar approaches could also be employed in conjugated polymer driven devices. IPMC based steerable catheters are further described in another chapter of this book. 

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