985 resultados para cell injection


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The heart muscle of a cardiac arrest victim continues to accumulate damage throughout its lifetime. This reduces the heart's ability to pump sufficient oxygen and nutrient blood to meet the body's needs. Medical researchers have shown that direct injection of pre-harvested skeletal myoblast cells into the heart can restore some muscle function [1]. This operative procedure usually necessitates the surgeon to open a patient's chest. The open chest procedure is usually a lengthy process and often extends the recovery time of the patient. Alternatively, a high accuracy surgical aid robotic system can be used to assist the thoracoscopic surgery [2][3]. While the robotic surgical method aids faster patient recovery, a less experienced surgeon can potentially cause damage to surrounding tissue.

This paper presents a study into the development of a virtual haptically-enabled heart myoblast injection simulation environment, which can be used to train new surgeons to get hands on experience with the process. The paper also discusses the development of a generic constraint motion technique for needle insertion. Experiments on human performance measures and efficacy, while interacting with haptic feedback training models, are also presented. The experiment involved 10 operators, with each person repeating the needle insertion and injection 10 times. A notable improvement in the task execution time with the number of repetitions was observed. Operators improved their time by up to 300% compared to their first training attempt for a static heart scenario. Under a dynamic heart motion, operator's performance was slightly lower, with the successful rate of completing the experiment reduced from 84% to 75%.

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Introducing haptic interface to conduct microrobotic intracellular injection has many beneficial implications. In particular, the haptic device provides force feedback to the bio-operator's hand. This paper introduces a 3D particle-based model to simulate the deformation of the cell membrane and corresponding cellular forces during microrobotic cell injection. The model is based on the kinematic and dynamic of spring – damper multi particle joints considering visco-elastic fluidic properties. It simulates the indentation force feedback as well as cell visual deformation during the microinjection. The model is verified using experimental data of zebrafish embryo microinjection. The results demonstrate that the developed cell model is capable of estimating zebrafish embryo deformation and force feedback accurately.

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Microrobotic cell injection is the subject of increasing research interest. At present, an operator relies completely on visual information and can be subject to low success rates, poor repeatability, and extended training times. This paper focuses on increasing operator performance during cell injection in two ways. First, our completed haptic cell injection system aims to increase the operator's performance during real-time cell injection. Haptic bilateralism is investigated and a mapping framework provides an intuitive method for manoeuvring the micropipette in a manner similar to handheld needle insertion. Volumetric virtual fixtures are then introduced to haptically assist the operator to penetrate the cell at the desired location. The performance of the volumetric virtual fixtures is also discussed. Second, the haptically enabled cell injection system is replicated as a virtual environment facilitating virtual offline operator training. Virtual operator training utilizes the same mapping framework and haptic virtual fixtures as the physical system allowing the operator to train offline and then directly transfer their skills to real-time cell injection.

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Micro-robotic cell injection is typically performed manually by a trainedbio-operator, and success rates are often low. To enhance bio-operator performance during real-time cell injection, our earlier work introduced a haptically-enabled micro-robotic cell injection system. The system employed haptic virtual fixtures to provide haptic guidance according to articular performance metrics. This paper extends the work by replicating the system within a virtual reality (VR) environment for bio-operator training. Using the virtual environment, the bio-operator is able to control the virtual injection process in the same way they would with the physical haptic micro-robotic cell injection system, while benefiting from the enhanced visualisation capabilities offered by the 3D VR environment. The system is achieved using cost-effective components offering training at much lower cost than using the physical system.

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The rapid development of virtual reality offers significant potential for skills training applications. Our ongoing work proposes virtual reality operator training for the micro-robotic cell injection procedure. The interface between the operator and the system can be achieved in many different ways. The computer keyboard is ubiquitous in its use for everyday computing applications and also commonly utilized in virtual reality systems. Based on the premise that most people have experience in using a computer keyboard, as opposed to more sophisticated input devices, this paper considers the feasibility of using a keyboard to control the micro-robot for cell injection. In this study, thirteen participants underwent the experimental evaluation. The participants were asked to perform three simulated trial sessions in a virtual micro-robotic cell injection environment. Each session consisted of ten cell injection trials and relevant data for each trial were recorded and analyzed. Results showed participants' performance improvement after the three sessions. It was also observed that participants intuitively controlled multiple axes of the micro-robot simultaneously despite the absence of instruction on how to do so. This continued throughout the experiments and suggests skills transfer from other keyboard based interactions. Based on the results provided, it is suggested that keyboard control is a feasible, simple and low-cost control method for the virtual micro-robot.

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Currently, the micro-robotic cell injection procedure is performed manually by expert human bio-operators. In order to be proficient at the task, lengthy and expensive dedicated training is required. As such, effective specialized training systems for this procedure can prove highly beneficial. This paper presents a comprehensive review of haptic technology relevant to cell injection training and discusses the feasibility of developing such training systems, providing researchers with an inclusive resource enabling the application of the presented approaches, or extension and advancement of the work. A brief explanation of cell injection and the challenges associated with the procedure are first presented. Important skills, such as accuracy, trajectory, speed and applied force, which need to be mastered by the bio-operator in order to achieve successful injection, are then discussed. Then an overview of various types of haptic feedback, devices and approaches is presented. This is followed by discussion on the approaches to cell modeling. Discussion of the application of haptics to skills training across various fields and haptically-enabled virtual training systems evaluation are then presented. Finally, given the findings of the review, this paper concludes that a haptically-enabled virtual cell injection training system is feasible and recommendations are made to developers of such systems.

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This paper discusses the design of a virtual reality (VR) training system for micro-robotic cell injection. A brief explanation of cell injection and the challenges associated with the procedure are first presented. This is followed by discussion of the skills required by the bio-operator to achieve successful injection, such as accuracy, trajectory and applied force. The design of the VR system which includes the visual display, input controllers, mapping strategies, haptic guidance and output data is then discussed. Initial evaluation of the VR system is presented including analysis and discussion based on conducted user evaluations. Finally, given the findings of the initial evaluation, this paper concludes that an effective haptically-enabled virtual cell injection training system is feasible, and recommendations for improvement and future work are given.

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This research was carried out to fill the gap within existing knowledge on the approaches to supplement the training for micro-robotic cell injection procedure by utilising virtual reality and haptic technologies.

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This paper proposes a system providing the operator with an intuitive method for controlling a micromanipulator during intracellular injection. A low-cost haptic device is utilised and 3D position-to-position kinematic mapping allows the operator to control the micropipette using a similar method to handheld needle insertion. The workspaces of the haptic device and micromanipulator are analysed and the importance of appropriate scaling to positioning resolution and tracking performance is investigated. The control issues integral to achieving adequate control of the micromanipulator using the Phantom Omni haptic device are addressed. Aside from offering an intuitive method for controlling the micropipette, this work lays the foundation for real-time haptic assistance in the cell injection task.

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The ability for a bio-operator to utilise a haptic device to manipulate a microrobot for intracellular injection offers immense benefits. One significant benefit is for the bio-operator to receive haptic guidance while performing the injection process. In order to address this, this paper investigates the use of haptic virtual fixtures for cell injection and proposes a novel force field virtual fixture. The guidance force felt by the bio-operator is determined by force field analysis within the virtual fixture. The proposed force field virtual fixture assists the bio-operator when performing intracellular injection by limiting the micropipette tip's motion to a conical volume as well as recommending the desired path for optimal injection. A virtual fixture plane is also introduced to prevent the bio-operator from moving the micropipette tip beyond the deposition target inside the cell. Simulation results demonstrate the operation of the guidance system.

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In manual cell injection the operator relies completely on visual information for task feedback and is subject to extended training times as well as poor success rates and repeatability. From this perspective, enhancing human-in-the-loop intracellular injection through haptic interaction offers significant benefits. This paper outlines two haptic virtual fixtures aiming to assist the human operator while performing cell injection. The first haptic virtual fixture is a parabolic force field designed to assist the operator in guiding the micropipette's tip to a desired penetration point on the cell's surface. The second is a planar virtual fixture which attempts to assist the operator from moving the micropipette's tip beyond the deposition target location inside the cell. Preliminary results demonstrate the operation of the haptically assisted microrobotic cell injection system.

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Microrobotic cell injection is an area of growing research interest. Typically, operators rely on visual feedback to perceive the microscale environment and are subject to lengthy training times and low success rates. Haptic interaction offers the ability to utilise the operator’s haptic modality and to enhance operator performance. Our earlier work presented a haptically enabled system for assisting the operator with certain aspects of the cell injection task. The system aimed to enhance the operator’s controllability of the micropipette through a logical mapping between the haptic device and microrobot, as well as introducing virtual fixtures for haptic guidance. The system was also designed in such a way that given the availability of appropriate force sensors, haptic display of the cell penetration force is straightforward. This work presents our progress towards a virtual replication of the system, aimed at facilitating offline operator training. It is suggested that operators can use the virtual system to train offline and later transfer their skills to the physical system. In order to achieve the necessary representation of the cell within the virtual system, methods based on a particle-based cell model are utilised. In addition to providing the necessary visual representation, the cell model provides the ability to estimate cell penetration forces and haptically display them to the operator. Two different approaches to achieving the virtual system are discussed.

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Introduction : Malgré leur état non-prolifératif in vivo, les cellules endothéliales cornéennes (CEC) peuvent être amplifiées in vitro. Leur transplantation subséquente par injection intracamérale pourrait surmonter la pénurie de tissus associée à l’allo-greffe traditionnelle – l’unique traitement définitif disponible pour les endothéliopathies cornéennes. Objectif : Évaluer la fonctionnalité d’un endothélium cornéen reconstitué par injection de CEC dans la chambre antérieure du félin. Méthodes : Les yeux droits de 16 animaux ont été opérés. Huit ont été désendothélialisés centralement avec injection de 2x10e5 (n=4) ou 1x10e6 (n=4) CEC félines supplémentées avec Y-27632 et marquées avec SP-DiOC18(3). Deux ont été désendothélialisés complètement et injectés avec 1x10e6 CEC et Y-27632. Six contrôles ont été désendothélialisés centralement (n=3) ou complètement (n=3) et injectés avec Y-27632 sans CEC. La performance clinique, l’intégrité anatomique, le phénotype fonctionnel et l’expression de SP-DiOC18(3) du nouvel endothélium ont été étudiés. Résultats : Les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement ont réussi le mieux cliniquement. Les contrôles désendothélialisés complètement sont restés opaques. L’histopathologie a révélé une monocouche endothéliale fonctionnelle dans les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement, une multicouche endothéliale non-fonctionnelle dans les cornées désendothélialisées centralement et greffées avec 1x10e6 CEC, et un endothélium fibrotique non-fonctionnel dans les cornées désendothélialisées complètement. L’expression de SP-DiOC18(3) était rare dans les greffes. Conclusion : La thérapie par injection cellulaire a reconstitué un endothélium partiellement fonctionnel, auquel les CEC injectées n’ont contribué que peu. L’injection de Y-27632 sans CEC a reconstitué l’endothélium le plus sain. Des études additionnelles investiguant l’effet thérapeutique de Y-27632 seul sont justifiées.

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Introduction : Malgré leur état non-prolifératif in vivo, les cellules endothéliales cornéennes (CEC) peuvent être amplifiées in vitro. Leur transplantation subséquente par injection intracamérale pourrait surmonter la pénurie de tissus associée à l’allo-greffe traditionnelle – l’unique traitement définitif disponible pour les endothéliopathies cornéennes. Objectif : Évaluer la fonctionnalité d’un endothélium cornéen reconstitué par injection de CEC dans la chambre antérieure du félin. Méthodes : Les yeux droits de 16 animaux ont été opérés. Huit ont été désendothélialisés centralement avec injection de 2x10e5 (n=4) ou 1x10e6 (n=4) CEC félines supplémentées avec Y-27632 et marquées avec SP-DiOC18(3). Deux ont été désendothélialisés complètement et injectés avec 1x10e6 CEC et Y-27632. Six contrôles ont été désendothélialisés centralement (n=3) ou complètement (n=3) et injectés avec Y-27632 sans CEC. La performance clinique, l’intégrité anatomique, le phénotype fonctionnel et l’expression de SP-DiOC18(3) du nouvel endothélium ont été étudiés. Résultats : Les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement ont réussi le mieux cliniquement. Les contrôles désendothélialisés complètement sont restés opaques. L’histopathologie a révélé une monocouche endothéliale fonctionnelle dans les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement, une multicouche endothéliale non-fonctionnelle dans les cornées désendothélialisées centralement et greffées avec 1x10e6 CEC, et un endothélium fibrotique non-fonctionnel dans les cornées désendothélialisées complètement. L’expression de SP-DiOC18(3) était rare dans les greffes. Conclusion : La thérapie par injection cellulaire a reconstitué un endothélium partiellement fonctionnel, auquel les CEC injectées n’ont contribué que peu. L’injection de Y-27632 sans CEC a reconstitué l’endothélium le plus sain. Des études additionnelles investiguant l’effet thérapeutique de Y-27632 seul sont justifiées.

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Background: Implantation and growth of metastatic cancer cells at distant organs is promoted by inflammation-dependent mechanisms. A hepatic melanoma metastasis model where a majority of metastases are generated via interleukin-18-dependent mechanisms was used to test whether anti-inflammatory properties of resveratrol can interfere with mechanisms of metastasis. Methods: Two experimental treatment schedules were used: 1) Mice received one daily oral dose of 1 mg/kg resveratrol after cancer cell injection and the metastasis number and volume were determined on day 12. 2) Mice received one daily oral dose of 1 mg/kg resveratrol along the 5 days prior to the injection of cancer cells and both interleukin-18 (IL-18) concentration in the hepatic blood and microvascular retention of luciferase-transfected B16M cells were determined on the 18(th) hour. In vitro, primary cultured hepatic sinusoidal endothelial cells were treated with B16M-conditioned medium to mimic their in vivo activation by tumor-derived factors and the effect of resveratrol on IL-18 secretion, on vascular cell adhesion molecule-1 (VCAM-1) expression and on tumor cell adhesion were studied. The effect of resveratrol on melanoma cell activation by IL-18 was also studied. Results: Resveratrol remarkably inhibited hepatic retention and metastatic growth of melanoma cells by 50% and 75%, respectively. The mechanism involved IL-18 blockade at three levels: First, resveratrol prevented IL-18 augmentation in the blood of melanoma cell-infiltrated livers. Second, resveratrol inhibited IL-18-dependent expression of VCAM-1 by tumor-activated hepatic sinusoidal endothelium, preventing melanoma cell adhesion to the microvasculature. Third, resveratrol inhibited adhesion-and proliferation-stimulating effects of IL-18 on metastatic melanoma cells through hydrogen peroxide-dependent nuclear factor-kappaB translocation blockade on these cells. Conclusions: These results demonstrate multiple sites for therapeutic intervention using resveratrol within the prometastatic microenvironment generated by tumor-induced hepatic IL-18, and suggest a remarkable effect of resveratrol in the prevention of inflammation-dependent melanoma metastasis in the liver.