Self-sensing feedback control of multiple interacting shape memory alloy actuators in a 3D steerable active needle

Abstract

Percutaneous needle-based intervention is a technique used in minimally invasive surgical procedures such as brachytherapy, thermal ablation, and biopsy. Targeting accuracy in these procedures is a defining factor for success. Active needle steering introduces the potential to increase the targeting accuracy in such procedures to improve the clinical outcome. In this work, a novel 3D steerable active flexible needle with shape memory alloy actuators was developed. Active needle actuation response to a variety of actuation scenarios was analyzed to develop a kinematic model. Shape memory alloy actuators were characterized in terms of their actuation strain, electrical resistance, and required electrical power to design a self-sensing electrical resistance feedback control system for position tracking control of the active needle. The control system performance was initially tested in position tracking control of a single shape memory alloy actuator and then was implemented on multiple interacting shape memory alloy actuators to manipulate the 3D steerable active needle along a reference path. The electrical resistance feedback control of the multiple interacting shape memory alloy actuators enabled the active needle to reach target points in a planar workspace of about 20 mm. Results demonstrated shape memory alloys as promising alternatives for traditional actuators used in surgical instruments with enhanced design, characterization, and control capabilities.

Kinematics modelling and dynamics analysis of an SMA-actuated active flexible needle for feedback-controlled manipulation in phantom

“…Then, the stretch ratios were calculated using numerical solution in MATLAB to find the deformation 𝜃𝜃 � of the flexible joints (results shown in Figure 13). More details on the needle tip position for each actuator can be found in our previous publication [27]. the control method showed a reasonable accuracy for the path tracking task on the entire triangular path, with average absolute error of 0.33mm.…”

“…The phantom samples were made using three different mixing weigh ratio of powder gelatine as samples to be used in proof of the concept for various material properties and were not examined to reflect material properties of any specific human organ. The SMA's material model and the relationship between the stress, strain, temperature, and electrical resistance of the SMA-wire actuators has been described in the authors' previous publications [27], [42]. The electrical resistance of the SMA-wire actuator was calculated accordingly.…”

“…Vision-based measurement (VBM) [25], [26] is a rapidly rising approach to quantitatively characterize response of a system in a variety of modelling and control applications. Vision-based characterization of the needle's response is demonstrated to accomplish efficient control algorithms [27].…”

Design and Control of Monolithic Compliant Gripper Using Shape Memory Alloy Wires

“…As mentioned by [ 23 ], self-sensing approaches were also developed for piezoelectric, SMA actuators and ionic polymers, to remove the complexity brought on by additional sensors. In the SMA-actuated flexible needle developed in [ 24 ], the resistance feedback control of the SMAs facilitate the active needle to reach target points. The self-sensing technique has been employed to deduce the gripper’s displacement feature from its electrical resistance.…”

Accurate sensorless displacement control based on the electrical resistance of the shape memory actuator

“…The use of electrical resistance (E.R.) as a sensor is investigated in a few references (Karimi and Konh, 2020; Prechtl et al, 2020; Sarmento et al, 2022; Simone et al, 2017; Urata et al, 2007). These studies focus on a SMA that undergoes a constant stress value.…”