scholarly journals Design of a Novel Three-Dimensional-Printed Two Degrees-of-Freedom Steerable Electrosurgical Grasper for Minimally Invasive Surgery

2018 ◽  
Vol 12 (1) ◽  
Author(s):  
Aimée Sakes ◽  
Kevin Hovland ◽  
Gerwin Smit ◽  
Jo Geraedts ◽  
Paul Breedveld
Keyword(s):  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Minimal Invasive ◽  
Activation Time ◽  
Medical Field ◽  
Active Electrode ◽  
3D Print ◽  
3D Printed ◽  
Specific Care

In current bipolar electrosurgical instruments, a high frequency electrical sinusoidal wave is passed through the patient's body from an active electrode to the return electrode to cut, coagulate, or desiccate tissues. Even though current bipolar electrosurgical instruments have proven effective in minimizing blood loss, advancement is needed to allow for improved dexterity and adaptability. With current advances in three-dimensional (3D)-print processes and its integration in the medical field, it has become possible to manufacture patient-and operation-specific instruments. In this study, we introduce the first 3D-printed steerable bipolar grasper (◻ 5 mm) for use in minimal invasive surgery. The grasper significantly improves dexterity by the addition of two planar joints allowing for ±65 deg for sideways and ±85 deg for up- and downward movement. The joints enable a significantly higher bending stiffness, 4.0 N/mm for joint 1 and 4.4 N/mm for joint 2, than that of currently available steerable instruments. The tip consists of two metallic movable jaws that can be opened and closed with angles up to 170 deg and allows for grasping and coagulating of tissues; reaching tissue temperatures of over 75 °C for an activation time of ∼5 s, respectively. In order to actuate the joint, tip, and electrosurgical system, as well as to tension the steering cables, a ring handle was designed. In summary, the 3D-printed steerable bipolar grasper provides the surgeon with electrosurgical capabilities, improved dexterity, improved stiffness, and the versatility that is needed to provide patient- and operation-specific care.

scholarly journals Effect of Selected Commercial Plasticizers on Mechanical, Thermal, and Morphological Properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer Biodegradable Blends for Three-Dimensional (3D) Print

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1893 ◽  
Author(s):  
Přemysl Menčík ◽  
Radek Přikryl ◽  
Ivana Stehnová ◽  
Veronika Melčová ◽  
Soňa Kontárová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Modulated Differential Scanning Calorimetry ◽  
3D Print ◽  
3D Printed ◽  
Biodegradable Blends

This paper explores the influence of selected commercial plasticizers structure, which are based on esters of citric acid, on mechanical and thermal properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer biodegradable blends. These plasticizers were first tested with respect to their miscibility with Poly(3-hydroxybutyrate)/Poly(lactic acid) (PHB/PLA) blends using a kneading machine. PHB/PLA/plasticizer blends in the weight ratio (wt %) of 60/25/15 were then prepared by single screw and corotating meshing twin screw extruders in the form of filament for further three-dimensional (3D) printing. Mechanical, thermal properties, and shape stability (warping effect) of 3D printed products can be improved just by the addition of appropriate plasticizer to polymeric blend. The goal was to create new types of eco-friendly PHB/PLA/plasticizers blends and to highly improve the poor mechanical properties of neat PHB/PLA blends (with majority of PHB) by adding appropriate plasticizer. Mechanical properties of plasticized blends were then determined by the tensile test of 3D printed test samples (dogbones), as well as filaments. Measured elongation at break rapidly enhanced from 21% for neat non-plasticized PHB/PLA blends (reference) to 328% for best plasticized blends in the form of filament, and from 5% (reference) to 187% for plasticized blends in the form of printed dogbones. The plasticizing effect on blends was confirmed by Modulated Differential Scanning Calorimetry. The study of morphology was performed by the Scanning Electron Microscopy. Significant problem of plasticized blends used to be also plasticizer migration, therefore the diffusion of plasticizers from the blends after 15 days of exposition to 110 °C in the drying oven was investigated as their measured weight loss. Almost all of the used plasticizers showed meaningful positive softening effects, but the diffusion of plasticizers at 110 °C exposition was quite extensive. The determination of the degree of disintegration of selected plasticized blend when exposed to a laboratory-scale composting environment was executed to roughly check the “biodegradability”.

scholarly journals One-click preparation of 3D print files (*.stl, *.wrl) from *.cif (crystallographic information framework) data using Cif2VRML

2014 ◽  
Vol 29 (S2) ◽  
pp. S42-S47 ◽  
Author(s):  
Werner Kaminsky ◽  
Trevor Snyder ◽  
Jennifer Stone-Sundberg ◽  
Peter Moeck
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
New Materials ◽  
3D Print ◽  
3D Printed ◽  
Information Framework

Ongoing software developments for creating three-dimensional (3D) printed crystallographic models seamlessly from Crystallographic Information Framework (CIF) data (*.cif files) are reported. Color versus monochrome printing is briefly discussed. Recommendations are made on the basis of our preliminary printing efforts. A brief outlook on new materials for 3D printing is given.

Robotic colorectal surgery: Where are we right now?

2010 ◽  
Vol 224 (7) ◽  
pp. 1415-1419 ◽  
Author(s):  
J Kang ◽  
K Y Lee
Keyword(s):  
Minimally Invasive Surgery ◽  
Robotic Surgery ◽  
Colorectal Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Colorectal Disease ◽  
Widespread Application ◽  
Robotic Colorectal Surgery

Minimally invasive surgery has become mainstream in surgical management of colorectal disease. Based on evidence of oncologic safety and benefit to patients, laparoscopic colorectal surgery is regarded as a successful alternative to open surgery. Since the introduction of the da Vinci® system as another tool for minimally invasive surgery, there have been several reports regarding the feasibility and safety of the system. The authors looked at their experience with 412 robotic colorectal surgeries and found that it was feasible and safe. Incidence of operation-related morbidity was around 11 per cent and system-related problems were 2.4 per cent. There was no operation-related or system-related mortality. From a technological perspective, robotic surgery has several advantages over laparoscopic surgery, including a magnifying view with a three-dimensional image, a stable camera platform, and instruments with Endowrist® technology that allow for seven degrees of freedom of movement. However, there is still room for improvement. The revolution of robotic technology can aid in the realization of a dream: a smaller, cheaper, and more sophisticated robotic system, which will further facilitate the widespread application of robotic surgery to colorectal disease.

scholarly journals The Role of 3D Printing in Medical Applications: A State of the Art

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Aimar ◽  
Augusto Palermo ◽  
Bernardo Innocenti
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Digital Information ◽  
Medical Implants ◽  
Medical Field ◽  
3D Printed ◽  
Pipe Dream ◽  
Manufacturing Technologies

Three-dimensional (3D) printing refers to a number of manufacturing technologies that generate a physical model from digital information. Medical 3D printing was once an ambitious pipe dream. However, time and investment made it real. Nowadays, the 3D printing technology represents a big opportunity to help pharmaceutical and medical companies to create more specific drugs, enabling a rapid production of medical implants, and changing the way that doctors and surgeons plan procedures. Patient-specific 3D-printed anatomical models are becoming increasingly useful tools in today’s practice of precision medicine and for personalized treatments. In the future, 3D-printed implantable organs will probably be available, reducing the waiting lists and increasing the number of lives saved. Additive manufacturing for healthcare is still very much a work in progress, but it is already applied in many different ways in medical field that, already reeling under immense pressure with regards to optimal performance and reduced costs, will stand to gain unprecedented benefits from this good-as-gold technology. The goal of this analysis is to demonstrate by a deep research of the 3D-printing applications in medical field the usefulness and drawbacks and how powerful technology it is.

Novel Miniature Tip Design for Enhancing Dexterity in Minimally Invasive Surgery

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
Aimée Sakes ◽  
Awaz Ali ◽  
Jovana Janjic ◽  
Paul Breedveld
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Tissue Characterization ◽  
Three Dimensional ◽  
Application Area ◽  
Technological Advances ◽  
Steel Cables ◽  
Shape Sensing

Even though technological advances have increased the application area of minimally invasive surgery (MIS), there are still hurdles to allow for widespread adoption for more complex procedures. The development of steerable instruments, in which the surgeon can alter the tip orientation, has increased the application area of MIS, but they are bulky, which limits their ability to navigate through narrow environments, and complex, which complicates miniaturization. Furthermore, they do not allow for navigating through complex anatomies. In an effort to improve the dexterity of the MIS instruments, while minimizing the outer dimensions, the previously developed cable-ring mechanism was redesigned, resulting in the thinnest, Ø 2 mm (Ø 1 mm lumen), eight degrees-of-freedom (DOF) multisteerable tip for MIS to date. The multisteerable tip consists of four steerable segments of 2DOF stackable elements allowing for ±90 deg articulation, as well the construction of complex shapes, actuated by 16 Ø 0.2 mm stainless steel cables. In a proof-of-principle experiment, an ultrasound transducer and optical shape sensing (OSS) fiber were inserted in the lumen, and the multisteerable tip was used to perform scanning motions in order to reconstruct a wire frame in three-dimensional (3D). This configuration could in future be used to safely navigate through delicate environments and allow for tissue characterization. Therefore, the multisteerable tip has the potential to increase the application area of MIS in future, as it allows for improved dexterity, the ability to guide several tip tools toward the operation area, and the ability to navigate through tight anatomies.

scholarly journals Structured Alumina Substrates for Environmental Catalysis Produced by Stereolithography

2021 ◽  
Vol 11 (17) ◽  
pp. 8239
Author(s):  
Oscar Santoliquido ◽  
Francesco Camerota ◽  
Marco Pelanconi ◽  
Davide Ferri ◽  
Martin Elsener ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Reduction ◽  
Combustion Engine ◽  
Periodic Structures ◽  
Three Dimensional ◽  
Precious Metals ◽  
Catalytic Efficiency ◽  
Active Phase ◽  
3D Print ◽  
3D Printed

Modern catalysts for internal combustion engine applications are traditionally constituted by honeycomb substrates on which a coating of the catalytically active phase is applied. Due to the laminar flow of the gases passing through their straight channels, these structures present low heat and mass transfer, thus leading to relatively large catalyst sizes to compensate for the low catalytic activity per unit of volume. Better conversion efficiency can be achieved if three-dimensional periodic structures are employed, because of the resulting gases’ tortuous paths. Furthermore, the increased catalytic activity implies a reduction in the overall catalyst volume, which can translate to a decreased usage of precious metals as active phase. By exploiting the ceramic Stereolithography technique (i.e., SLA) it is nowadays possible to accurately 3D print complex alumina-based lattices to be used as ceramic substrates for catalysis. In this work, closed-walls lattices consisting of a rotated cubic cell of 2 mm dimensions were designed, 3D printed via SLA and finally washcoated with V2O5-WO3-TiO2. The samples were tested for the selective catalytic reduction of NO by NH3 in a heated quartz glass reactor and the performance of the innovative 3D-printed substrate was compared with the catalytic efficiency of the conventional cordierite honeycombs.

Analysis of the influence of polylactic acid (PLA) colour on FDM 3D printing temperature and part finishing

2018 ◽  
Vol 24 (8) ◽  
pp. 1305-1316 ◽  
Author(s):  
Juliana Breda Soares ◽  
João Finamor ◽  
Fabio Pinto Silva ◽  
Liane Roldo ◽  
Luis Henrique Cândido
Keyword(s):  
Polylactic Acid ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Fused Deposition Modelling ◽  
Process Conditions ◽  
Content Type ◽  
3D Print ◽  
Fused Deposition ◽  
3D Printed

Purpose This paper aims to analyse the effect of different polylactic acid (PLA) colours used on fused deposition modelling (FDM), considering the product finishing quality produced with the same process conditions. Design/methodology/approach The methodology adopted was to design a virtual modelling object and three-dimensional (3D) print it with FDM with different PLA colours (natural, green and black), using the same parameters. 3D scanning and scanning electron microscopy was used to analyse the model finishing of each sample. Fourier-transform infrared spectroscopy analysis, thermogravimetric analysis and dynamic mechanical analysis were used to characterize the material and verify if the colour affected its thermal behaviour. Findings Findings showed that different PLA colours lead to distinct 3D printed finishings under the same process conditions. Thermal analysis showed a reason for the printing finishing difference. The degradation temperatures and the glass temperatures vary depending on the PLA colour. This affects the FDM working temperature. Originality/value This study will contribute to improving the finishing quality of 3D printed products by collaborating to the determination of its process conditions.

scholarly journals Mechanically reconfigurable multi-functional meta-optics studied at microwave frequencies

2020 ◽  
Author(s):  
Conner Ballew ◽  
Gregory Roberts ◽  
Philip Camayd-Muñoz ◽  
Maximilien Debbas ◽  
Andrei Faraon
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Single Layer ◽  
Proof Of Concept ◽  
Optical Components ◽  
Microwave Frequencies ◽  
Reconfigurable Devices ◽  
Minimal Thickness ◽  
3D Printed ◽  
Advanced Applications

Abstract Metasurfaces advanced the field of optics by reducing the thickness of optical components and merging multiple functionalities into a single layer device. However, this generally comes with a reduction in performance, especially for multi-functional and broadband applications. Three-dimensional metastructures can provide the necessary degrees of freedom for advanced applications, while maintaining minimal thickness. This work explores 3D mechanically reconfigurable devices that perform focusing, spectral demultiplexing, and polarization sorting based on mechanical configuration. As proof of concept, a rotatable device, auxetic device, and a shearing-based device are designed with adjoint-based topology optimization, 3D-printed, and measured at microwave frequencies (7.6-11.6 GHz) in an anechoic chamber.

scholarly journals Mechanically reconfigurable multi-functional meta-optics studied at microwave frequencies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Conner Ballew ◽  
Gregory Roberts ◽  
Sarah Camayd-Muñoz ◽  
Maximilien F. Debbas ◽  
Andrei Faraon
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Single Layer ◽  
Proof Of Concept ◽  
Optical Components ◽  
Microwave Frequencies ◽  
Reconfigurable Devices ◽  
Minimal Thickness ◽  
3D Printed ◽  
Advanced Applications

AbstractMetasurfaces advanced the field of optics by reducing the thickness of optical components and merging multiple functionalities into a single layer device. However, this generally comes with a reduction in performance, especially for multi-functional and broadband applications. Three-dimensional metastructures can provide the necessary degrees of freedom for advanced applications, while maintaining minimal thickness. This work explores mechanically reconfigurable devices that perform focusing, spectral demultiplexing, and polarization sorting based on mechanical configuration. As proof of concept, a rotatable device, a device based on rotating squares, and a shearing-based device are designed with adjoint-based topology optimization, 3D-printed, and measured at microwave frequencies (7.6–11.6 GHz) in an anechoic chamber.

scholarly journals Mechanical Follow-the-Leader motion of a hyper-redundant surgical instrument: Proof-of-concept prototype and first tests

2019 ◽  
Vol 233 (11) ◽  
pp. 1141-1150 ◽  
Author(s):  
Paul WJ Henselmans ◽  
Gerwin Smit ◽  
Paul Breedveld
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Surgical Procedures ◽  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Three Dimensional ◽  
The Body ◽  
Standard Size ◽  
Mechanical Approach

One of the most prominent drivers in the development of surgical procedures is the will to reduce their invasiveness, attested by minimally invasive surgery being the gold standards in many surgical procedures and natural orifices transluminal endoscopic surgery gaining acceptance. A logical next step in this pursuit is the introduction of hyper-redundant instruments that can insert themselves along multi-curved paths referred to as Follow-the-Leader motion. In the current state of the art, two different types of Follow-the-Leader instruments can be distinguished. One type of instrument is robotized; the movements of the shaft are controlled from outside the patient by actuators, for example, electric motors, and a controller storing a virtual track of the desired path. The other type of instrument is more mechanical; the movements of the shaft are controlled from inside the patient by a physical track that guides the shaft along the desired path. While in the robotized approach all degrees of freedom of the shaft require an individual actuator, the mechanical approach makes the number of degrees of freedom independent from the number of actuators. A desirable feature as an increasing number of actuators will inevitably drive up costs and increase the footprint of an instrument. Building the physical track inside the body does, however, impede miniaturization of the shaft’s diameter. This article introduces a new fully mechanical approach for Follow-the-Leader motion using a pre-determined physical track that is placed outside the body. This new approach was validated with a prototype called MemoFlex, which supports a Ø5 mm shaft (standard size in minimally invasive surgery) that contains 28-degrees-of-freedom and utilizes a simple steel rod as its physical track. Even though the performance of the MemoFlex leaves room for improvement, especially when following multiple curves, it does validate the proposed concept for Follow-the-Leader motion in three-dimensional space.

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