Small diameter active catheter using shape memory alloy

Haga, Yoichi; Tanahashi, Yoshikatsu; Esashi, Masayoshi

doi:10.1109/memsys.1998.659793

Cited by 74 publications

(48 citation statements)

References 3 publications

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“…NiTi memory elements have been used (among other things) in: stents [21]; catheters [22]; actuators for robotic and biomimetic systems [23]- [27]; morphing aircraft structures [20]; orthopedic implants [20]; systems for structural health monitoring [28]; robotic pumps [29]; and even as integrated elements in clothing [30]. SMAs offer high blocking stresses (200 MPa), high specific power (>100 kW/kg), and can be actuated using Joule heating via an applied current [12].…”

Section: Theory and Modeling Of Niti Coil Actuatorsmentioning

confidence: 99%

Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

Holschuh

Obropta

Newman

2015

IEEE/ASME Trans. Mechatron.

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Abstract-This paper describes the modeling, development, and testing of low spring index nickel titanium (NiTi) coil actuators designed for use in wearable compression garments, and presents a prototype tourniquet system using these actuators. NiTi coil actuators produce both large forces (>1 N) and large recoverable displacements (>100% length) that are well suited for compression garment design. Thermomechanical coil models are presented that describe temperature and force as a function of non-dimensionalized coil geometry, extensional strain, and applied voltage. These models suggest that low spring index coils maximize activation force, and an analytical model is presented to predict garment counter-pressure based on actuator architecture. Several low spring index (C = 3.08) coils were manufactured, annealed, and tested to assess their de-twinning and activation characteristics. Results suggest both annealing and applied stress affect activation thresholds. Actuator force increases both with extensional strain and applied voltage up to 7.24 N. A first-generation compression tourniquet system using integrated actuators with direct voltage-control of applied pressure is presented, demonstrating >70% increase in applied pressure during activation. This approach enables new, dynamic garments with controllable activation and low effort donning and doffing, with applications ranging from healthcare solutions to advanced space suit design.

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Section: Theory and Modeling Of Niti Coil Actuatorsmentioning

confidence: 99%

Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

Holschuh

Obropta

Newman

2015

IEEE/ASME Trans. Mechatron.

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“…[1][2][3][4][5][6][7][8][9][10] Many types of materials exhibit shape changing properties, including (but not limited to) shape memory alloys (SMAs), shape memory polymers (SMPs), dielectric elastomer actuators (DEAs), and ionic polymer metal composites (IPMCs). 1 We are investigating the use of one of these materials, SMAs, as low mass, low bulk, large force and large displacement actuators.…”

Section: Introductionmentioning

confidence: 99%

Low spring index, large displacement Shape Memory Alloy (SMA) coil actuators for use in macro- and micro-systems

Holschuh

Newman

2014

SPIE Proceedings

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Shape memory alloys (SMA) offer unique shape changing characteristics that can be exploited to produce lowmass, low-bulk, large-stroke actuators. We are investigating the use of low spring index (defined as the ratio of coil diameter to wire diameter) SMA coils for use as actuators in morphing aerospace systems. Specifically, we describe the development and characterization of minimum achievable spring index coiled actuators made from 0.3048 mm (0.012") diameter shape memory alloy (SMA) wire for integration in textile architectures for future compression space suit applications. Production and shape setting of the coiled actuators, as well as experimental test methods, are described. Force, length and voltage relationships for multiple coil actuators are reported and discussed. The actuators exhibit a highly linear (R 2 > 0.99) relationship between isometric blocking force and coil displacement, which is consistent with current SMA coil models; and SMA coil actuators demonstrate the ability to produce significant linear forces (i.e., greater than 8 N per coil) at strains up to 3x their initial (i.e., fully coiled) length. Discussions of both the potential use of these actuators in future compression space suit designs, and the broader viability of these actuators in both macro-and micro-systems, are presented.

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“…As the application of robots expands in demanding fields such as in vivo surgical tools as active catheters and endoscopes [1], [2], exploration robots [3], and dexterous robotic manipulators [4], the need for embedding more degrees of freedom (DoF) while maintaining minimum mass and size is emerging. Cable-driven mechanisms are the prevailing solution to remove the actuators from the joint area [5] in order to miniaturize the manipulator.…”

Section: Introductionmentioning

confidence: 99%

An under actuated robotic arm with adjustable stiffness shape memory polymer joints

Firouzeh

Salehian

Billard

et al. 2015

2015 IEEE International Conference on Robotics and Automation (ICRA)

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Abstract-Various robotic applications including surgical instruments, wearable robots and autonomous mobile robots are often constrained with strict design requirements on high degrees of freedom (DoF) and minimal volume and weight. An intuitive design to meet these contradictory requirements is to embed locking mechanism in under actuated robotic manipulators to direct the actuation from a single and remote source to drive different joints on demand. Mechanical clutches do serve such purposes but often are bulky and require auxiliary mechanism making it difficult to justify the high cost adding the additional DoF, especially in cm scale.Here, we introduce an under-actuated robotic arm with shape memory polymer (SMP) joints. Through controlling the temperature, the stiffness of the joints can be adjusted and selected joints will be activated while the rest are fixed in their position. The presented prototype can control the joints independently with a coupled actuation from two stepper motors. Since we have redundant DoFs in the arm, there can be more than one configuration to reach a given position. We use a probabilistic technique to determine the optimum configuration with the minimum number of active joints that can yield the desired posture. In this paper, we report on the performance of the proposed design for the hardware and the configuration planner.

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Small diameter active catheter using shape memory alloy

Cited by 74 publications

References 3 publications

Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

Low spring index, large displacement Shape Memory Alloy (SMA) coil actuators for use in macro- and micro-systems

An under actuated robotic arm with adjustable stiffness shape memory polymer joints

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