367 research outputs found

    studio e sviluppo di un sistema di visione per capsule endoscopiche mobili in ambiente liquido

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    Negli ultimi anni si è sviluppata l’endoscopia con capsule che consente una diagnosi del tratto gastrointestinale minimamente invasiva, costituendo un ottimo strumento di screening per la popolazione. Tuttavia, per quanto riguarda la gastroscopia dello stomaco, non esistono ad oggi capsule endoscopiche. L’obiettivo di questo lavoro di tesi è quello di realizzare un sistema integrato funzionale, utilizzabile ai fini della gastroscopia minimamente invasiva dello stomaco

    A soft multi-module manipulator with variable stiffness for minimally invasive surgery

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    This work presents a soft manipulator for minimally invasive surgery inspired by the biological capabilities of the octopus arm. The multi-module arm is composed of three identical units, which are able to move thanks to embedded fluidic actuators that allow omnidirectional bending and elongation, typical movements of the octopus. The use of soft materials makes the arm safe, adaptable and compliant with tissues. In addition, a granular jamming-based stiffening mechanism is integrated in each module with the aim of tuning the stiffness of the manipulator and controlling the interactions with biological structures. A miniaturized camera and a pneumatic gripper have been purposely designed and integrated on the tip of the manipulator making it usable in real working conditions. This work reports the design and the fabrication process of the manipulator, the theoretical and experimental evaluation of the stiffness and the analysis of the motion workspace. Finally, pick and place tests with the fully integrated system are shown

    Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery

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    In recent years, soft robotics technologies have aroused increasing interest in the medical field due to their intrinsically safe interaction in unstructured environments. At the same time, new procedures and techniques have been developed to reduce the invasiveness of surgical operations. Minimally Invasive Surgery (MIS) has been successfully employed for abdominal interventions, however standard MIS procedures are mainly based on rigid or semi-rigid tools that limit the dexterity of the clinician. This paper presents a soft and high dexterous manipulator for MIS. The manipulator was inspired by the biological capabilities of the octopus arm, and is designed with a modular approach. Each module presents the same functional characteristics, thus achieving high dexterity and versatility when more modules are integrated. The paper details the design, fabrication process and the materials necessary for the development of a single unit, which is fabricated by casting silicone inside specific molds. The result consists in an elastomeric cylinder including three flexible pneumatic actuators that enable elongation and omni-directional bending of the unit. An external braided sheath improves the motion of the module. In the center of each module a granular jamming-based mechanism varies the stiffness of the structure during the tasks. Tests demonstrate that the module is able to bend up to 120° and to elongate up to 66% of the initial length. The module generates a maximum force of 47 N, and its stiffness can increase up to 36%

    A Miniature Robot for Retraction Tasks under Vision Assistance in Minimally Invasive Surgery

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    Minimally Invasive Surgery (MIS) is one of the main aims of modern medicine. It enables surgery to be performed with a lower number and severity of incisions. Medical robots have been developed worldwide to offer a robotic alternative to traditional medical procedures. New approaches aimed at a substantial decrease of visible scars have been explored, such as Natural Orifice Transluminal Endoscopic Surgery (NOTES). Simple surgical tasks such as the retraction of an organ can be a challenge when performed from narrow access ports. For this reason, there is a continuous need to develop new robotic tools for performing dedicated tasks. This article illustrates the design and testing of a new robotic tool for retraction tasks under vision assistance for NOTES. The retraction robots integrate brushless motors to enable additional degrees of freedom to that provided by magnetic anchoring, thus improving the dexterity of the overall platform. The retraction robot can be easily controlled to reach the target organ and apply a retraction force of up to 1.53 N. Additional degrees of freedom can be used for smooth manipulation and grasping of the organ

    A Soft Modular Manipulator for Minimally Invasive Surgery: Design and Characterization of a Single Module

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    This paper presents the concept design of a modular soft manipulator for minimally invasive surgery. Unlike traditional surgical manipulators based on metallic steerable needles, tendon-driven mechanisms, or articulated motorized links, we combine flexible fluidic actuators to obtain multidirectional bending and elongation with a variable stiffness mechanism based on granular jamming. The idea is to develop a manipulator based on a series of modules, each consisting of a silicone matrix with pneumatic chambers for 3-D motion, and one central channel for the integration of granular-jamming-based stiffening mechanism. A bellows-shaped braided structure is used to contain the lateral expansion of the flexible fluidic actuator and to increase its motion range. In this paper, the design and experimental characterization of a single module composed of such a manipulator is presented. Possible applications of the manipulator in the surgical field are discussed

    STIFF-FLOP surgical manipulator: Mechanical design and experimental characterization of the single module

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    This paper presents the concept design, the fabrication and the experimental characterization of a unit of a modular manipulator for minimal access surgery. Traditional surgical manipulators are usually based on metallic steerable needles, tendon driven mechanisms or articulated motorized links. In this work the main idea is to combine flexible fluidic actuators enabling omnidirectional bending and elongation capability and the granular jamming phenomenon to implement a selective stiffness changing. The proposed manipulator is based on a series of identical modules, each one consisting of a silicone tube with pneumatic chambers for allowing 3D motion and one central channel for the implementation of the granular jamming phenomenon for stiffening. The silicone is covered by a novel bellows-shaped braided structure maximizing the bending still limiting lateral expansion. In this paper one single module is tested in terms of bending range, elongation capability, generated forces and stiffness changing

    Pulsed-Xenon Ultraviolet Light Highly Inactivates Human Coronaviruses on Solid Surfaces, Particularly SARS-CoV-2

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    In the context of ongoing and future pandemics, non-pharmaceutical interventions are critical in reducing viral infections and the emergence of new antigenic variants while the population reaches immunity to limit viral transmission. This study provides information on efficient and fast methods of disinfecting surfaces contaminated with different human coronaviruses (CoVs) in healthcare settings. The ability to disinfect three different human coronaviruses (HCoV-229E, MERS-CoV, and SARS-CoV-2) on dried surfaces with light was determined for a fully characterized pulsed-xenon ultraviolet (PX-UV) source. Thereafter, the effectiveness of this treatment to inactivate SARS-CoV-2 was compared to that of conventional low-pressure mercury UVC lamps by using equivalent irradiances of UVC wavelengths. Under the experimental conditions of this research, PX-UV light completely inactivated the CoVs tested on solid surfaces since the infectivity of the three CoVs was reduced up to 4 orders of magnitude by PX-UV irradiation, with a cumulated dose of as much as 21.162 mJ/cm2 when considering all UV wavelengths (5.402 mJ/cm2 of just UVC light). Furthermore, continuous irradiation with UVC light was less efficient in inactivating SARS-CoV-2 than treatment with PX-UV light. Therefore, PX-UV light postulates as a promising decontamination measure to tackle the propagation of future outbreaks of CoVs

    Antitumor activity of new pyrazolo[3,4-d]pyrimidine SRC kinase inhibitors in Burkitt lymphoma cell lines and its enhancement by WEE1 inhibition

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    Burkitt lymphoma (BL) is a highly aggressive B-cell neoplasm. Although intensive polychemotherapy regimens have proven very effective, they are associated with significant toxicities. Therefore, more rational therapies that selectively target the molecular abnormalities of BL are needed. Recent data suggest that the tyrosine kinase SRC could represent a therapeutic target for BL. We found that new pyrazolo[3,4-d]pyrimidine SRC inhibitors exerted a significant cytotoxic effect and induced apoptosis on two BL cell lines, as determined by MTS assays, cytofluorimetric analyses and caspase 3 assay. Notably, our SRC inhibitors proved to be more effective than the well-known SRC inhibitor PP 2 [4-amino-5- (4‑chlorophenyl)-7-(dimethylethyl)pyrazolo[3,4-d]pyrimidine] in BL cells. Moreover, our small molecules induced a G2/M arrest in BL cells through a possible new mechanism, whereby SRC inhibition hinders an AKT-WEE 1-cyclin-dependent kinase 1 (CDK1) axis, leading to inhibition of CDK1, the main trigger of entry into mitosis. By using a small-molecule inhibitor of WEE 1, a crucial CDK1 negative regulator, we were able to shift the balance toward apoptosis rather than growth arrest and enhance the efficacy of the SRC inhibitors, suggesting a possible use of these selective drugs in combination for a safe and efficient treatment of BL
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