The Experts below are selected from a list of 29685 Experts worldwide ranked by ideXlab platform
Masamichi Kamihira - One of the best experts on this subject based on the ideXlab platform.
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functional evaluation of Artificial skeletal muscle Tissue constructs fabricated by a magnetic force based Tissue engineering technique
Tissue Engineering Part A, 2011Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masamichi KamihiraAbstract:Skeletal muscle Tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle Tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional Artificial skeletal muscle Tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the Artificial Tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the Tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the Tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the Artificial Tissue constructs contracted to generate a phy...
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preparation of Artificial skeletal muscle Tissues by a magnetic force based Tissue engineering technique
Journal of Bioscience and Bioengineering, 2009Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masahiro Kato, Kazunori Shimizu, Masamichi KamihiraAbstract:Artificial muscle Tissues composed of mouse myoblast C2C12 cells were prepared using a magnetic force-based Tissue engineering technique. C2C12 cells labeled with magnetite nanoparticles were seeded into the wells of 24-well ultralow-attachment culture plates. When a magnet was positioned underneath each plate, the cells accumulated evenly on the culture surface and formed multilayered cell sheets. Since the shapes of Artificial Tissue constructs can be controlled by magnetic force, cellular string-like assemblies were formed by using a linear magnetic field concentrator with a magnet. However, the resulting cellular sheets and strings shrank considerably and did not retain their shapes during additional culture periods for myogenic differentiation. On the other hand, when a silicone plug was positioned at the center of the well during the fabrication of a cell sheet, the cell sheet shrank drastically and formed a ring-like assembly around the plug. A histological examination revealed that the cells in the cellular ring were highly oriented in the direction of the circumference by the tension generated within the structure. Individual cellular rings were hooked around two pins separated by 10 mm, and successfully cultured for 6 d without breakage. After a 6-d culture in differentiation medium, the C2C12 cells differentiated to form myogenin-positive multinucleated myotubes. Highly dense and oriented skeletal muscle Tissues were obtained using this technique, suggesting that this procedure may represent a novel strategy for muscle Tissue engineering.
Yasunori Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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functional evaluation of Artificial skeletal muscle Tissue constructs fabricated by a magnetic force based Tissue engineering technique
Tissue Engineering Part A, 2011Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masamichi KamihiraAbstract:Skeletal muscle Tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle Tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional Artificial skeletal muscle Tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the Artificial Tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the Tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the Tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the Artificial Tissue constructs contracted to generate a phy...
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preparation of Artificial skeletal muscle Tissues by a magnetic force based Tissue engineering technique
Journal of Bioscience and Bioengineering, 2009Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masahiro Kato, Kazunori Shimizu, Masamichi KamihiraAbstract:Artificial muscle Tissues composed of mouse myoblast C2C12 cells were prepared using a magnetic force-based Tissue engineering technique. C2C12 cells labeled with magnetite nanoparticles were seeded into the wells of 24-well ultralow-attachment culture plates. When a magnet was positioned underneath each plate, the cells accumulated evenly on the culture surface and formed multilayered cell sheets. Since the shapes of Artificial Tissue constructs can be controlled by magnetic force, cellular string-like assemblies were formed by using a linear magnetic field concentrator with a magnet. However, the resulting cellular sheets and strings shrank considerably and did not retain their shapes during additional culture periods for myogenic differentiation. On the other hand, when a silicone plug was positioned at the center of the well during the fabrication of a cell sheet, the cell sheet shrank drastically and formed a ring-like assembly around the plug. A histological examination revealed that the cells in the cellular ring were highly oriented in the direction of the circumference by the tension generated within the structure. Individual cellular rings were hooked around two pins separated by 10 mm, and successfully cultured for 6 d without breakage. After a 6-d culture in differentiation medium, the C2C12 cells differentiated to form myogenin-positive multinucleated myotubes. Highly dense and oriented skeletal muscle Tissues were obtained using this technique, suggesting that this procedure may represent a novel strategy for muscle Tissue engineering.
Allison M Okamura - One of the best experts on this subject based on the ideXlab platform.
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toward human robot collaboration in surgery performance assessment of human and robotic agents in an inclusion segmentation task
International Conference on Robotics and Automation, 2016Co-Authors: Kirsten E Kaplan, Kirk A Nichols, Allison M OkamuraAbstract:Increasing the level of autonomy in robot-assisted surgery has the potential to improve the safety, speed, and applicability of robot-assisted surgical systems. To facilitate the development and incorporation of robot autonomy in clinical settings, human-robot collaboration models have been suggested in which human and robotic agents work together to accomplish a task. In this work, we measure performance of several human-robot collaboration models in two experiments based on the task of segmenting a stiff inclusion in soft Tissue, which simulates a tumor. In the inclusion segmentation experiment, twelve participants explored an Artificial Tissue and identified the inclusion boundary under the collaboration models of (1) teleoperation, (2) supervised control, (3) traded control, and (4) full autonomy. In the boundary identification experiment, we isolate the performance of human and robotic agents in the boundary identification sub-task; participants and a robotic agent independently identified the boundary of four virtually palpated Tissues. Results from the inclusion segmentation experiment indicate that human agents complete the task faster; teleoperation had the fastest task times. Results of both experiments indicate that the robotic agent identifies boundaries with higher sensitivity and less variance than human agents. This indicates that task accuracy increases when a robotic agent segments the boundary, while including a human agent can decrease the overall task time.
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tactor induced skin stretch as a sensory substitution method in teleoperated palpation
IEEE Transactions on Human-Machine Systems, 2015Co-Authors: Samuel B Schorr, Ilana Nisky, Zhan Fan Quek, William R Provancher, Allison M OkamuraAbstract:When we use a tool to explore or manipulate an object, friction between the surface of the tool and the fingerpads generates skin stretch cues that are related to the interaction forces between the tool and the object. In this study, we emulate these naturally occurring skin stretch cues in order to convey force direction and magnitude information to users during teleoperation. We hypothesize that skin stretch feedback is a useful substitute for kinesthetic force feedback in force-sensitive teleoperated tasks. In this study, ten participants performed teleoperated palpation to determine the orientation of a stiff region in a surrounding Artificial Tissue using five feedback conditions: skin stretch, force, reduced gain force, graphic, and vibration. When participants received skin stretch feedback, they localized the stiff region as well as with force feedback, with no increase in task completion time. Additionally, participants receiving skin-stretch feedback localized the stiff region statistically significantly more accurately than those using vibration feedback. Although participants using skin stretch exhibited higher interaction forces than when using force, vibration, and graphical feedback, skin stretch statistically significantly decreased interaction forces compared with reduced gain force feedback. Thus, skin-stretch feedback is a compelling substitute for force feedback and may be useful in scenarios where force feedback is reduced or infeasible.
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methods to segment hard inclusions in soft Tissue during autonomous robotic palpation
IEEE Transactions on Robotics, 2015Co-Authors: Kirk A Nichols, Allison M OkamuraAbstract:Localizing tumors and measuring Tissue mechanical properties can aid in surgical planning and evaluating the progression of disease. In this paper, autonomous robotic palpation with supervised machine learning algorithms enables mechanical localization and segmentation of stiff inclusions in Artificial Tissue. Elastography generates training data for the learning algorithms, providing a noninvasive, inclusion-specific characterization of Tissue mechanics. Once an embedded hard inclusion was identified in the elastographic image, Gaussian discriminant analysis generated a classifier to threshold stiffness values acquired from autonomous robotic palpation. This classifier was later used to classify newly acquired points as either part of the inclusion or surrounding soft Tissue. An expectation-maximization algorithm with underlying Markov random fields improved this initial classifier over successive iterations to better approximate the boundary of the inclusion. Results demonstrate robustness with respect to inclusion shape, size, and the initial classifier value. For three trials segmenting a cubic inclusion, sensitivity was above 0.95 and specificity was above 0.92.
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autonomous robotic palpation machine learning techniques to identify hard inclusions in soft Tissues
International Conference on Robotics and Automation, 2013Co-Authors: Kirk A Nichols, Allison M OkamuraAbstract:Localizing tumors and measuring Tissue mechanical properties can be useful for surgical planning and evaluating progression of disease. In this paper, supervised machine learning algorithms enable mechanical localization of stiff inclusions in Artificial Tissue after autonomous robotic palpation. Elastography is used to generate training data for the learning algorithms, providing a non-invasive, inclusion-specific characterization of Tissue biomechanics. In particular, elastography was used to characterize the stiffness of Artificial Tissue with an embedded hard inclusion. Once the inclusion was identified on the elastographic image, machine learning methods identified the difference in stiffness between the inclusion and surrounding soft Tissue and generated classifiers, which were used to label stiffness values as either part of the inclusion or soft Tissue. Next, data acquired via autonomous robotic palpation of the Artificial Tissue created a map of the stiffness distributed over the surface of the Tissue. The points in this map were thresholded against the classifiers trained by the machine learning algorithms, and points theorized to belong to the hard inclusion were labeled. Centroid approximations of the hard inclusion based on this labeling show that classifying stiffness data acquired by autonomous robotic palpation and labeled by a classifier trained from elastography data provides a more accurate method of localizing hard inclusions than using unclassified data.
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augmented reality and haptic interfaces for robot assisted surgery
International Journal of Medical Robotics and Computer Assisted Surgery, 2012Co-Authors: Tomonori Yamamoto, Allison M Okamura, Niki Abolhassani, Sung Jung, Timothy N JudkinsAbstract:Background Current teleoperated robot-assisted minimally invasive surgical systems do not take full advantage of the potential performance enhancements offered by various forms of haptic feedback to the surgeon. Direct and graphical haptic feedback systems can be integrated with vision and robot control systems in order to provide haptic feedback to improve safety and Tissue mechanical property identification. Methods An interoperable interface for teleoperated robot-assisted minimally invasive surgery was developed to provide haptic feedback and augmented visual feedback using three-dimensional (3D) graphical overlays. The software framework consists of control and command software, robot plug-ins, image processing plug-ins and 3D surface reconstructions. Results The feasibility of the interface was demonstrated in two tasks performed with Artificial Tissue: palpation to detect hard lumps and surface tracing, using vision-based forbidden-region virtual fixtures to prevent the patient-side manipulator from entering unwanted regions of the workspace. Conclusions The interoperable interface enables fast development and successful implementation of effective haptic feedback methods in teleoperation. Copyright © 2011 John Wiley & Sons, Ltd.
Akira Ito - One of the best experts on this subject based on the ideXlab platform.
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functional evaluation of Artificial skeletal muscle Tissue constructs fabricated by a magnetic force based Tissue engineering technique
Tissue Engineering Part A, 2011Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masamichi KamihiraAbstract:Skeletal muscle Tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle Tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional Artificial skeletal muscle Tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the Artificial Tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the Tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the Tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the Artificial Tissue constructs contracted to generate a phy...
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preparation of Artificial skeletal muscle Tissues by a magnetic force based Tissue engineering technique
Journal of Bioscience and Bioengineering, 2009Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masahiro Kato, Kazunori Shimizu, Masamichi KamihiraAbstract:Artificial muscle Tissues composed of mouse myoblast C2C12 cells were prepared using a magnetic force-based Tissue engineering technique. C2C12 cells labeled with magnetite nanoparticles were seeded into the wells of 24-well ultralow-attachment culture plates. When a magnet was positioned underneath each plate, the cells accumulated evenly on the culture surface and formed multilayered cell sheets. Since the shapes of Artificial Tissue constructs can be controlled by magnetic force, cellular string-like assemblies were formed by using a linear magnetic field concentrator with a magnet. However, the resulting cellular sheets and strings shrank considerably and did not retain their shapes during additional culture periods for myogenic differentiation. On the other hand, when a silicone plug was positioned at the center of the well during the fabrication of a cell sheet, the cell sheet shrank drastically and formed a ring-like assembly around the plug. A histological examination revealed that the cells in the cellular ring were highly oriented in the direction of the circumference by the tension generated within the structure. Individual cellular rings were hooked around two pins separated by 10 mm, and successfully cultured for 6 d without breakage. After a 6-d culture in differentiation medium, the C2C12 cells differentiated to form myogenin-positive multinucleated myotubes. Highly dense and oriented skeletal muscle Tissues were obtained using this technique, suggesting that this procedure may represent a novel strategy for muscle Tissue engineering.
Yoshinori Kawabe - One of the best experts on this subject based on the ideXlab platform.
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functional evaluation of Artificial skeletal muscle Tissue constructs fabricated by a magnetic force based Tissue engineering technique
Tissue Engineering Part A, 2011Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masamichi KamihiraAbstract:Skeletal muscle Tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle Tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional Artificial skeletal muscle Tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the Artificial Tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the Tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the Tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the Artificial Tissue constructs contracted to generate a phy...
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preparation of Artificial skeletal muscle Tissues by a magnetic force based Tissue engineering technique
Journal of Bioscience and Bioengineering, 2009Co-Authors: Yasunori Yamamoto, Akira Ito, Hideaki Fujita, Eiji Nagamori, Yoshinori Kawabe, Masahiro Kato, Kazunori Shimizu, Masamichi KamihiraAbstract:Artificial muscle Tissues composed of mouse myoblast C2C12 cells were prepared using a magnetic force-based Tissue engineering technique. C2C12 cells labeled with magnetite nanoparticles were seeded into the wells of 24-well ultralow-attachment culture plates. When a magnet was positioned underneath each plate, the cells accumulated evenly on the culture surface and formed multilayered cell sheets. Since the shapes of Artificial Tissue constructs can be controlled by magnetic force, cellular string-like assemblies were formed by using a linear magnetic field concentrator with a magnet. However, the resulting cellular sheets and strings shrank considerably and did not retain their shapes during additional culture periods for myogenic differentiation. On the other hand, when a silicone plug was positioned at the center of the well during the fabrication of a cell sheet, the cell sheet shrank drastically and formed a ring-like assembly around the plug. A histological examination revealed that the cells in the cellular ring were highly oriented in the direction of the circumference by the tension generated within the structure. Individual cellular rings were hooked around two pins separated by 10 mm, and successfully cultured for 6 d without breakage. After a 6-d culture in differentiation medium, the C2C12 cells differentiated to form myogenin-positive multinucleated myotubes. Highly dense and oriented skeletal muscle Tissues were obtained using this technique, suggesting that this procedure may represent a novel strategy for muscle Tissue engineering.
