Tissue Interaction

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Shangbing Ai - One of the best experts on this subject based on the ideXlab platform.

James D. Murray - One of the best experts on this subject based on the ideXlab platform.

  • Travelling waves in a Tissue Interaction model for skin pattern formation.
    Journal of Mathematical Biology, 1994
    Co-Authors: G. C. Cruywagen, Philip K. Maini, James D. Murray
    Abstract:

    Tissue Interaction plays a major role in many morphogenetic processes, particularly those associated with skin organ primordia. We examine travelling wave solutions in a Tissue Interaction model for skin pattern formation which is firmly based on the known biology. From a phase space analysis we conjecture the existence of travelling waves with specific wave speeds. Subsequently, analytical approximations to the wave profiles are derived using perturbation methods. We then show numerically that such travelling wave solutions do exist and that they are in good agreement with our analytical results. Finally, the biological implications of our analysis are discussed.

  • Threshold Bifurcation in Tissue Interaction Models for Spatial Pattern Generation
    Philosophical Transactions of the Royal Society A, 1994
    Co-Authors: James D. Murray, Gerhard C. Cruywagen
    Abstract:

    Experimental evidence indicates that Tissue Interaction plays an essential role during skin pattern formation. Here we focus on the mathematical aspects of two specific Tissue Interaction models. Introducing Interaction mechanisms into the traditional pattern formation models is not only biologically consistent, but also leads to results agreeing more closer to those observed in embryogenesis. We specifically examine the bifurcations from spatially simple solutions to spatially complex patterns. In both models this increased complexity in solution is obtained by increasing the effect of the Interaction mechanism through a certain threshold. The role of Tissue Interaction in sequential patterning is also considered.

  • Bifurcating Spatial Patterns Arising from Travelling Waves in a Tissue Interaction Model
    Applied Mathematics Letters, 1994
    Co-Authors: G. C. Cruywagen, Philip K. Maini, James D. Murray
    Abstract:

    We analyse a Tissue Interaction model recently proposed to account for pattern formation in the morphogenesis of skin organ primordia. We show that the model can exhibit travelling wave solutions which leave in their wake a spatially nonuniform, steady state solution.

  • On a Tissue Interaction Model for Skin Pattern Formation
    Journal of Nonlinear Science, 1992
    Co-Authors: G. C. Cruywagen, James D. Murray
    Abstract:

    There is now sound biological evidence that dermal-epidermal communication is essential in the formation of skin organs. Recent experimental results suggest that cell adhesion molecules (CAMs) play an important role during skin pattern formation. We describe here a Tissue Interaction model for pattern morphogenesis in vertebrate skin which includes such CAMs. A mechanochemical mechanism is used to describe epithelial sheet motion, and a reaction-diffusion-chemotaxis mechanism is used to model the dermal cell movements. Neither of the mechanisms can independently generate spatial patterns in their respective layers. Tissue Interaction is introduced using morphogens produced separately in the dermis and epithelium. These morphogens diffuse across the basal lamina, which separates the epidermis and dermis, and induce cell movements and deformation. Analysis of a simplified one-dimensional version shows that under certain conditions spatial patterns can be formed. A nonlinear analysis predicts the solution behavior which is in close agreement with the numerical results.

Russell C. Jackson - One of the best experts on this subject based on the ideXlab platform.

  • Needle-Tissue Interaction force state estimation for robotic surgical suturing
    2016 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2016
    Co-Authors: Russell C. Jackson, Viraj Desai, Jean P. Castillo, Cenk M. Çavuşoğlu
    Abstract:

    Robotically Assisted Minimally Invasive Surgery (RAMIS) offers many advantages over manual surgical techniques. Most of the limitations of RAMIS stem from its nonintuitive user interface and costs. One way to mitigate some of the limitations is to automate surgical subtasks (e.g. suturing) such that they are performed faster while allowing the surgeon to plan the next step of the procedure. One component of successful suture automation is minimizing the internal Tissue deformation forces generated by driving a needle through Tissue. Minimizing the internal Tissue forces requires segmenting the Tissue deformation forces from other components of the needle Tissue Interaction (e.g. friction force). This paper proposes an Unscented Kalman Filter which can successfully model the force components, in particular the internal deformation force, generated by a needle as it is driven through a sample of Tissue.

  • ICRA - Modeling of needle-Tissue Interaction forces during surgical suturing
    IEEE International Conference on Robotics and Automation : ICRA : [proceedings]. IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Russell C. Jackson, M. Cenk Cavusoglu
    Abstract:

    This paper presents a model of needle Tissue Interaction forces that a rigid suture needle experiences during surgical suturing. The needle-Tissue Interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, Tissue compression, and cutting forces. The Tissue compression force uses the area that the needle sweeps out during a suture to estimate both the force magnitude and force direction. The area that the needle sweeps out is a direct result of driving the needle in a way that does not follow the natural curve of the needle. The friction force is approximated as a static friction force along the shaft of the needle. The cutting force acts only on the needle tip. The resulting force and torque model is experimentally validated using a Tissue phantom. These results indicate that the proposed lumped parameter model is capable of accurately modeling the forces experienced during a suture.

  • Modeling of needle-Tissue Interaction forces during surgical suturing
    Proceedings - IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Russell C. Jackson, Murat Cenk Çavuşoǧlu
    Abstract:

    This paper presents a model of needle Tissue Interaction forces that a rigid suture needle experiences during surgical suturing. The needle-Tissue Interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, Tissue compression, and cutting forces. The Tissue compression force uses the area that the needle sweeps out during a suture to estimate both the force magnitude and force direction. The area that the needle sweeps out is a direct result of driving the needle in a way that does not follow the natural curve of the needle. The friction force is approximated as a static friction force along the shaft of the needle. The cutting force acts only on the needle tip. The resulting force and torque model is experimentally validated using a Tissue phantom. These results indicate that the proposed lumped parameter model is capable of accurately modeling the forces experienced during a suture.

Jurgen Lademann - One of the best experts on this subject based on the ideXlab platform.

  • Stimulation of the penetration of particles into the skin by plasma Tissue Interaction
    Laser Physics Letters, 2011
    Co-Authors: Olaf Lademann, E. Korotianskiy, Qigang Gao, Alexa Patzelt, Heike Richter, Edgar Stüssi, Axel Kramer, C. Graf, Martina C Meinke, Jurgen Lademann, Klaus-dieter Weltmann, Stefan Koch
    Abstract:

    A high number of treatments in dermatology are based on the penetration\nof topically applied drugs through the skin barrier. This process is\npredominantly inefficient, on account of the strong protection\nproperties of the upper skin layer - the stratum corneum. If the skin\nbarrier is damaged, the penetration efficiency of topically applied\ndrugs increases. Therefore, different methods have been developed to\ninfluence the barrier properties of the skin.\nRecently, it could be demonstrated that a cold Tissue tolerable plasma\n(TTP) produced by a plasma-jet can strongly enhance drug delivery\nthrough the skin. These investigations were performed by using a\nsolution of fluorescent dye as a model drug. In the present study, these\ninvestigations were carried out using fluorescent silica particles at\ndifferent sizes. The aim of the study was to investigate whether or not\nthere is a limitation in size for topically applied substances to pass\nthrough the skin barrier after plasma treatment.

  • Laser spectroscopic investigation of radical formation during laser-Tissue Interaction
    ICONO '98: Laser Spectroscopy and Optical Diagnostics: Novel Trends and Applications in Laser Chemistry Biophysics and Biomedicine, 1999
    Co-Authors: Jurgen Lademann, Hans-juergen Weigmann, Wolfram Sterry, Gerhard J. Mueller
    Abstract:

    Laser spectroscopic measurements are an effective method for the on-line investigation of formation processes of harmful substances during laser treatment of Tissue in medicine. Specific radicals like CO, CO2, CN, OH, CN, CH2, C2, NH, SH, CS produced during laser application for cutting and evaporation of Tissue characterize the kind of laser Tissue Interaction. The molecule fragments in the ground or excited states have been detected in dependence on the applied medical laser system by spontaneous or laser induced fluorescence. The chemical reaction processes in the laser Tissue Interaction zone can be changed significantly by the surrounding gas atmosphere. An increasing oxygen content in the surrounding atmosphere reduces the amount of harmful substances in the laser plume. The laser spectroscopic investigation inside the reaction zone reflects clearly the interplay of complete and incomplete oxidation in dependence on different gas atmospheres in the reaction zone. The application of pure oxygen and oxygen enriched gases is limited in laser medicine because of safety regulating. Therefore water was used as an oxygen donor. The water was added into the laser Tissue Interaction zone using a water aerosol spray. The oxygen was released during the laser treatment with the result of the water dissociation under the high temperature conditions. The production of toxic and carcinogenic substances was reduced significantly by this method. The cutting efficiency in the case of water spray application is unchanged in comparison to the treatment without water spray but the quality can be improved, as histological investigations demonstrate.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Radical formation during laser-Tissue Interaction
    Laser-Tissue Interaction and Tissue Optics II, 1996
    Co-Authors: Jurgen Lademann, Hans-juergen Weigmann, H. Meffert, Wolfram Sterry
    Abstract:

    Laser spectroscopic methods have been used for on-line investigations of laser Tissue Interaction processes concerning the production of toxic and carcinogenic substances in the laser plume during cutting and evaporation of Tissue in laser surgery. Laser spectroscopic investigations demonstrated that the original Tissue molecules were split into basic metastable compounds under the high temperature conditions in the reaction zone. The produced radicals are one source for the formation of the chemical s produced during the laser Tissue Interaction process. The formation of the harmful substances can be influenced by the surrounding gas atmosphere. These substances can be reduced significantly by the addition of an oxygen donor e.g. water, into the reaction zone.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Characterization of laser Tissue Interaction processes by laser spectroscopic measurements
    Laser-Tissue Interaction and Tissue Optics, 1996
    Co-Authors: Jurgen Lademann, Hans-juergen Weigmann, Wolfram Sterry, H. Audring, H. Meffert
    Abstract:

    The specific possibilities of the time-resolved fluorescence spectroscopy have been used to determine in on-line measurements the reactive species arising in the reaction zone during laser Tissue Interaction. The measured radicals, ions and excited atoms are the basic components for the formation of stable harmful chemicals observed in laser plume and therefore the best parameters for the optimization of the laser Tissue Interaction process. A water aerosol spray system that reduces the emission of the harmful components in the laser plume is described. The effectiveness of this arrangement depends strongly on the water concentration in the Interaction zone. The determination of C2, CH and CN radicals which lead to the formation of harmful substances and the OH and O species which characterize the water content of the Tissue by laser spectroscopic measurements gives the possibility to optimize the Interaction process.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Investigation of laser-Tissue Interaction in medicine by means of laser spectroscopic measurements
    Laser Interaction with Hard and Soft Tissue II, 1995
    Co-Authors: Jurgen Lademann, Hans-juergen Weigmann
    Abstract:

    Toxic and carcinogenic substances were produced during laser application in medicine for the cutting and evaporation of Tissue. The laser smoke presents a danger potential for the medical staff and the patients. The laser Tissue Interaction process was investigated by means of laser spectroscopic measurements which give the possibility of measuring metastable molecular states directly as a prerequisite to understand and to influence fundamental laser Tissue Interaction processes in order to reduce the amount of harmful chemicals. Highly excited atomic and molecular states and free radicals (CN, OH, C2, CH, CH2) have been detected applying spontaneous and laser induced fluorescence methods. It was found that the formation of harmful substances in the laser plumes can be reduced significantly by optimization of the surrounding gas atmosphere. A high content of oxygen or water in the Interaction zone has been found, in agreement with the results of classical and analytical methods, as a suitable way to decrease pollutant emission. The experimental methods and the principal results are applicable not only in laser medicine but in laser material treatment generally.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Murat Cenk Çavuşoǧlu - One of the best experts on this subject based on the ideXlab platform.

  • Modeling of needle-Tissue Interaction forces during surgical suturing
    Proceedings - IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Russell C. Jackson, Murat Cenk Çavuşoǧlu
    Abstract:

    This paper presents a model of needle Tissue Interaction forces that a rigid suture needle experiences during surgical suturing. The needle-Tissue Interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, Tissue compression, and cutting forces. The Tissue compression force uses the area that the needle sweeps out during a suture to estimate both the force magnitude and force direction. The area that the needle sweeps out is a direct result of driving the needle in a way that does not follow the natural curve of the needle. The friction force is approximated as a static friction force along the shaft of the needle. The cutting force acts only on the needle tip. The resulting force and torque model is experimentally validated using a Tissue phantom. These results indicate that the proposed lumped parameter model is capable of accurately modeling the forces experienced during a suture.

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