Novel Steerable Smart Needle With a Built-In Recovery Mechanism for Multiple Actuations

Author(s):  
Mohammad Sahlabadi ◽  
Kyle Jezler ◽  
Parsaoran Hutapea

Smart Memory Alloys have brought a range of new capabilities to existing and novel designs due to their unique properties and ability to induce stress and strain in the material due to thermomechanical loading. Shape memory alloy-based smart material has widely been used and studied for biomedical applications. This includes smart needle for percutaneous procedures, self-expanding Nitinol grafts, stents, and other permanent internal devices. The smart needle is a needle in which deflection/path of the insertion in tissues can be controlled by incorporating Nitinol wire actuators on the body of the needle. However, smart needle designs proposed in the past lack both flexibility for multidirectional angles, and they do not allow for multiple martensitic phase transformations and are thus not repeatable. Each time the Nitinol wire is actuated, the wire would have to be manually reset to its initial length. Active materials like Nitinol require a bias force or mechanism that reverts the activated form of the needle back to its original martensitic form, which in the case of active needles is a straight wire. The lack of a recovery mechanism means that subsequent austenite transformations for deflection in opposing or similar trajectories cannot be performed as the system will not fully reset itself once cooled. In our proposed design, four Nitinol wires are embedded into a needle and act independently of one another to provide multi directional needle deformations. By providing tension onto a flexible 3D printed needle shaft, they can pivot a hard needle tip into any given direction. Once the needle’s deformation is complete, the material’s natural rigidity coupled with other Nitinol wires pulling resistance will restore the initial length of the actuated wire as it cools. This allows the needle to undergo a martensitic transformation and then subsequent cooling followed by additional phase transformation in a different direction. This makes the needle’s mechanism repeatable and functional for multiple insertions.

2018 ◽  
Vol 31 (1) ◽  
pp. 143-171 ◽  
Author(s):  
M. J. CHEN ◽  
L. S. KIMPTON ◽  
J. P. WHITELEY ◽  
M. CASTILHO ◽  
J. MALDA ◽  
...  

Tissue engineering aims to grow artificial tissues in vitro to replace those in the body that have been damaged through age, trauma or disease. A recent approach to engineer artificial cartilage involves seeding cells within a scaffold consisting of an interconnected 3D-printed lattice of polymer fibres combined with a cast or printed hydrogel, and subjecting the construct (cell-seeded scaffold) to an applied load in a bioreactor. A key question is to understand how the applied load is distributed throughout the construct. To address this, we employ homogenisation theory to derive equations governing the effective macroscale material properties of a periodic, elastic–poroelastic composite. We treat the fibres as a linear elastic material and the hydrogel as a poroelastic material, and exploit the disparate length scales (small inter-fibre spacing compared with construct dimensions) to derive macroscale equations governing the response of the composite to an applied load. This homogenised description reflects the orthotropic nature of the composite. To validate the model, solutions from finite element simulations of the macroscale, homogenised equations are compared to experimental data describing the unconfined compression of the fibre-reinforced hydrogels. The model is used to derive the bulk mechanical properties of a cylindrical construct of the composite material for a range of fibre spacings and to determine the local mechanical environment experienced by cells embedded within the construct.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 986 ◽  
Author(s):  
Denesh Mohan ◽  
Nur Fatin Khairullah ◽  
Yan Ping How ◽  
Mohd Shaiful Sajab ◽  
Hatika Kaco

Drug delivery constitutes the formulations, technologies, and systems for the transport of pharmaceutical compounds to specific areas in the body to exert safe therapeutic effects. The main criteria for selecting the correct medium for drug delivery are the quantity of the drug being carried and the amount of time required to release the drug. Hence, this research aimed to improve the aforementioned criteria by synthesizing a medium based on calcium carbonate-nanocellulose composite and evaluating its efficiency as a medium for drug delivery. Specifically, the efficiency was assessed in terms of the rates of uptake and release of 5-fluorouracil. Through the evaluation of the morphological and chemical properties of the synthesized composite, the established 3D printing profiles of nanocellulose and CaCO3 took place following the layer-by-layer films. The 3D printed double laminated CaCO3-nanocellulose managed to release the 5-fluorouracil as an effective single composition and in a time-controlled manner.


2020 ◽  
Vol 31 (16) ◽  
pp. 1920-1934 ◽  
Author(s):  
Chen Liang ◽  
Yongquan Wang ◽  
Tao Yao ◽  
Botao Zhu

This article presents a soft crawling robot prototype with a simple architecture inspired by inchworms. The robot functionally integrates the torso (body) and feet in a monolithic curved structure that only needs a single shape memory alloy coil and differential friction to actuate it. A novel foot configuration is proposed, which makes the two feet, with an anti-symmetrical friction layout, can be alternately anchored, to match the contraction–recovery sequence of the body adaptively. Based on the antagonistic configuration between the shape memory alloy actuator and the elastic body, a vertically auxiliary spring was adopted to enhance the interaction mechanism. Force and kinematic analysis was undertaken, focusing on the parametric design of the special foot configuration. A miniature robot prototype was then 3D-printed (54 mm in length and 9.77 g in weight), using tailored thermoplastic polyurethane elastomer as the body material. A series of experimental tests and evaluations were carried out to assess its performance under different conditions. The results demonstrated that under appropriate actuation conditions, the compact robot prototype could accomplish a relative speed of 0.024 BL/s (with a stride length equivalent to 27% of its body length) and bear a load over five times to its own weight.


2014 ◽  
Vol 41 (10) ◽  
pp. 869-877 ◽  
Author(s):  
Gabriel B. Dadi ◽  
Timothy R.B. Taylor ◽  
Paul M. Goodrum ◽  
William F. Maloney

Engineering information delivery can be a source of inefficient communication of design, leading to construction rework and lower worker morale. Due to errors, omissions, and misinterpretations, there remains a great opportunity to improve the traditional documentation of engineering information that craft professionals use to complete their work. Historically, physical three dimensional (3D) models built by hand provided 3D physical representations of the project to assist in sequencing, visualization, and planning of critical construction activities. This practice has greatly diminished since the adoption of 3D computer-aided design (CAD) and building information modeling technologies. Recently, additive manufacturing (a.k.a. 3D printing) technologies have allowed for three dimensional printing of 3D CAD models. A cognitive experiment was established to measure the effectiveness of 2D drawings, a 3D computer model, and a 3D printed model in delivering engineering information to an end-user are scientifically measured. The 3D printed model outperformed the 2D drawings and 3D computer interface in productivity measures. This paper’s primary contribution to the body of knowledge is identification of how different mediums of engineering information influence the performance of a simple task execution.


Author(s):  
Sebastian Hernandez ◽  
Sofiane Achiche ◽  
Daniel Spooner ◽  
Aurelian Vadean ◽  
Maxime Raison

Abstract Over the last decades, the use of multibody dynamics in biomechanics research has grown considerably and holds significant promises for the health and biomedical industries. Nowadays, it allows estimating internal data of the body that would be impractical or impossible to obtain experimentally, e.g. individual muscle forces. Also, multibody dynamics simulation allows one to constrain virtually any apparatus to the musculoskeletal system, helping to understand and improve the patient’s dynamic interactions with the device. The modeling and validation of human multibody models remain a tedious task to achieve for the research community and can vary significantly depending on the applications. Despite the advantages offered by the multibody modeling of the human body, its introduction in the biomedical engineering curriculum is not widespread. The present paper aims to evaluate the feasibility and the interest of introducing multibody modeling into multidisciplinary, real-world projects using 3D printed prototypes to add an experimental understanding of the difficulties and validation of the human body modeling. The proposed methodology is based on a literature review of the multibody dynamics teaching methods used in mechanical engineering, followed by a first pilot project and feedback from students and professors of the community through interviews. Finally, a project is proposed, using physical prototyping to support the learning.


2018 ◽  
Vol 12 (3) ◽  
Author(s):  
Mohammad Sahlabadi ◽  
Parsaoran Hutapea

Surgical needles are commonly used to reach target locations inside of the body for percutaneous procedures. The major issues in needle steering in tissues are the insertion force which causes tissue damage and tissue deformation that causes the needle path deviation (i.e., tip deflection) resulting in the needle missing the intended target. In this study, honeybee-inspired needle prototypes were proposed and studied to decrease the insertion force and to reduce the tissue deformation. Three-dimensional (3D) printing technology was used to manufacture scaled-up needle prototypes. Needle insertion tests on tissue-mimicking polyvinyl chloride (PVC) gel were performed to measure the insertion force and the tip deflection. Digital image correlation (DIC) study was conducted to determine the tissue deformation during the insertion. It was demonstrated that the bioinspired needles can be utilized to decrease the insertion force by 24% and to minimize the tip deflection. It was also observed that the bioinspired needles decrease the tissue deformation by 17%. From this study, it can be concluded that the proposed bee-inspired needle design can be used to develop and manufacture innovative surgical needles for more effective and less invasive percutaneous procedures.


Author(s):  
Maoen Pan ◽  
Chaoqian Zhao ◽  
Zeya Xu ◽  
Yuanyuan Yang ◽  
Tianhong Teng ◽  
...  

Long-term placement of non-degradable silicone rubber pancreatic duct stents in the body is likely to cause inflammation and injury. Therefore, it is necessary to develop degradable and biocompatible stents to replace silicone rubber tubes as pancreatic duct stents. The purpose of our research was to verify the feasibility and biological safety of extrusion-based 3D printed radiopaque chitosan (CS) ducts for pancreaticojejunostomy. Chitosan-barium sulfate (CS-Ba) ducts with different molecular weights (low-, medium-, and high-molecular weight CS-Ba: LCS-Ba, MCS-Ba, and HCS-Ba, respectively) were soaked in vitro in simulated pancreatic juice (SPJ) (pH 8.0) with or without pancreatin for 16 weeks. Changes in their weight, water absorption rate and mechanical properties were tested regularly. The biocompatibility, degradation and radiopaque performance were verified by in vivo and in vitro experiments. The results showed that CS-Ba ducts prepared by this method had regular compact structures and good molding effects. In addition, the lower the molecular weight of the CS-Ba ducts was, the faster the degradation rate was. Extrusion-based 3D-printed CS-Ba ducts have mechanical properties that match those of soft tissue, good biocompatibility and radioopacity. In vitro studies have also shown that CS-Ba ducts can promote the growth of fibroblasts. These stents have great potential for use in pancreatic duct stent applications in the future.


2020 ◽  
Vol 4 (2) ◽  
pp. 1-109
Author(s):  
J. Sage Elwell

Abstract This slim volume offers a thematic exploration of religion and the digital arts. Over the course of six brief sections, this extended essay examines identity and community, authority and authenticity, word and image, ritual and practice, body and space, and myth and faith. Each of these paired sets is explored in concert with technologically inflected correlates. For instance, identity and community are paired with avatars and networks. These twin concepts provide the thematic anchor of each section. Each section looks at four works of digital art with each work employing digital technology in a unique way. The works include virtual and augmented reality pieces, 3D printed sculptures, digital photography, and digitally enabled performance pieces and installations and span the late 1990s to the present. This essay is an introduction to religion and the digital arts and, while no single conclusion can be drawn from such an expansive and diverse field, the reassertion of the religious and theological importance of the body and emotions in the face of digital technology emerges as a recurrent theme.


2020 ◽  
pp. 155335062094556
Author(s):  
Zahra K. Varnamkhasti ◽  
Bardia Konh

Needle-based intervention has been a popular procedure for diagnosis and treatment of many types of cancer. However, poor needle placement and tumor visualization have been among the challenges resulting in poor clinical outcomes. There has been a lot of progress in medical imaging technology, but the structure of surgical needles has remained unchanged. This work presents a wire-driven 3D steerable, 3D-printed active needle for improved guidance inside the tissue toward the target. The needle is manipulated by 3 embedded tendons via a programmed motorized control unit. Feasibility tests in a tissue phantom showed an average 3D needle angular deflection of about 11°. This amount of angular deflection is expected to assist prostate brachytherapy via a curvilinear approach.


Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Seongbeom Ahn ◽  
Woojun Jung ◽  
Kyungho Ko ◽  
Yeongchan Lee ◽  
Chanju Lee ◽  
...  

Typical pneumatic soft micro actuators can be manufactured without using heavy driving components such as pumps and power supplies by adopting an independent battery-powered mechanism. In this study, a thermopneumatically operated soft micro bellows actuator was manufactured, and the standalone operation of the actuator was experimentally validated. Thermopneumatic actuation is based on heating a sealed cavity inside the elastomer of the actuator to raise the pressure, leading to deflection of the elastomer. The bellows actuator was fabricated by casting polydimethylsiloxane (PDMS) using the 3D-printed soluble mold technique to prevent leakage, which is inherent in conventional soft lithography due to the bonding of individual layers. The heater, manufactured separately using winding copper wire, was inserted into the cavity of the bellows actuator, which together formed the thermopneumatic actuator. The 3D coil heater and bellows allowed immediate heat transfer and free movement in the intended direction, which is unachievable for conventional microfabrication. The fabricated actuator produced a stroke of 2184 μm, equivalent to 62% of the body, and exerted a force of 90.2 mN at a voltage of 0.55 V. A system in which the thermopneumatic actuator was driven by alkaline batteries and a control circuit also demonstrated a repetitive standalone operation.


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