Takashi Ijiri, T. Ashihara, Nobuyuki Umetani, Yuki Koyama, T. Igarashi, R. Haraguchi, H. Yokota, K. Nakazawa
A shape matching dynamics (SMD) is a robust and efficient elastic model based on geometric constraints. This article introduces our study #1$ that adopts SMD to visual simulation of cardiac beating motion. In our technique, a heart is represented by a tetrahedral mesh model and a local region is defined at each vertex by connecting its immediate neighbors. During the simulation, we first contract all local regions depending on predefined muscle fiber orientations and contraction rate. Then using SMD, we compute the global shape of the heart model so that it satisfies the contracted local regions. Our technique introduces a fiber-orientationdependent weighting function to emulate an anisotropic stiffness of myocardium. Since our technique is based on SMD, it is possible to compute cardiac motion in real-time on a commercially available PC.
{"title":"Visual simulation of cardiac beating motion with shape matching dynamics","authors":"Takashi Ijiri, T. Ashihara, Nobuyuki Umetani, Yuki Koyama, T. Igarashi, R. Haraguchi, H. Yokota, K. Nakazawa","doi":"10.11239/JSMBE.53.130","DOIUrl":"https://doi.org/10.11239/JSMBE.53.130","url":null,"abstract":"A shape matching dynamics (SMD) is a robust and efficient elastic model based on geometric constraints. This article introduces our study #1$ that adopts SMD to visual simulation of cardiac beating motion. In our technique, a heart is represented by a tetrahedral mesh model and a local region is defined at each vertex by connecting its immediate neighbors. During the simulation, we first contract all local regions depending on predefined muscle fiber orientations and contraction rate. Then using SMD, we compute the global shape of the heart model so that it satisfies the contracted local regions. Our technique introduces a fiber-orientationdependent weighting function to emulate an anisotropic stiffness of myocardium. Since our technique is based on SMD, it is possible to compute cardiac motion in real-time on a commercially available PC.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81843494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Amano, Florencio Punzalan Rusty, T. Shimayoshi, Y. Kunieda
Many biological findings are continuously reported in the life science area. Most of them are reports on the correlations between some proteins, or correlations between some proteins and macroscopic phenomena such as whole body hemodynamics. In order to understand the underlying mechanisms of the biological systems, simulation and analysis of multiscale biological function models are considered useful. Since the complex calculation schemes are necessary to calculate these models efficiently, it is useful to represent both the biological function models and the calculation schemes in descriptive languages which are readable by the computer programs. In this report, we introduce our simulation system which generates simulation programs from biological function models and calculation schemes both described by description languages. Using our system, we were able to generate simulation programs for a hemodynamic simulation model coupling a ventricular myocyte model and a whole body circulation model, a simulation model that evaluates the changes in action potential of a ventricular myocyte model after drug administration, and a program that calculates the changes in action potential of ventricular myocytes by changing specific parameters.
{"title":"Simulation system for multiscale biological function models that require complex calculation scheme","authors":"A. Amano, Florencio Punzalan Rusty, T. Shimayoshi, Y. Kunieda","doi":"10.11239/JSMBE.53.115","DOIUrl":"https://doi.org/10.11239/JSMBE.53.115","url":null,"abstract":"Many biological findings are continuously reported in the life science area. Most of them are reports on the correlations between some proteins, or correlations between some proteins and macroscopic phenomena such as whole body hemodynamics. In order to understand the underlying mechanisms of the biological systems, simulation and analysis of multiscale biological function models are considered useful. Since the complex calculation schemes are necessary to calculate these models efficiently, it is useful to represent both the biological function models and the calculation schemes in descriptive languages which are readable by the computer programs. In this report, we introduce our simulation system which generates simulation programs from biological function models and calculation schemes both described by description languages. Using our system, we were able to generate simulation programs for a hemodynamic simulation model coupling a ventricular myocyte model and a whole body circulation model, a simulation model that evaluates the changes in action potential of a ventricular myocyte model after drug administration, and a program that calculates the changes in action potential of ventricular myocytes by changing specific parameters.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80603188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kaoru Natsume, S. Irisawa, S. Onogi, T. Mochizuki, K. Masuda
Microbubbles are widely used as contrast agents in ultrasound diagnosis. Microbubbles may also has therapeutic uses in the heat amplification of high-intensity focused ultrasound ablation or as carriers of acoustic targeted drug gene delivery therapy. However, microbubbles injected into a blood vessel are diffused throughout the whole body ; therefore, their efficiency is still limited. If microbubbles could be controlled in vivo, their efficiency and efficacy would be significantly improved. To address this issue, we have proposed a technique that controls microbubble behavior in blood vessels using ultrasound emitted from the body surface. To apply the technique in vivo, robotic ultrasound transducer positioning on body surface is required. For this purpose, we have developed a robotic system and confirmed that microbubble can be manipulated by the system. In more practical condition, focal length of an ultrasound transducer has to be considered. To address the issue, we propose a control system considering the focal length in this study. The system consists of a parallel-link robot for ultrasound transducer positioning, a robot controller, and an optical tracking device. The robot has three arms, and a transducer holder, and a six-axis force sensor. The robot controller generates ultrasound emission plans using body surface position measured by the tracking device, and manipulate the robot. As for validation of the system, we performed following experiments ; 1) positioning accuracy evaluation without contact, 2) evaluation of contact forces control, and 3) in vitro ultrasound emission tests. From the first experiment, positioning accuracy was less than 1 mm. As for the contact force control validation, the system could keep required reaction force for ultrasound emission on a phantom surface within 1.5 mm errors. In the third experiment, the errors in the perpendicular direction of the ultrasound axis and the direction of the axis were 0.71 mm and 5.52 mm, respectively. From the results, we confirmed that the system could emit ultrasound to a target by using a hydrophone in a poly(ethylene glycol) monomethacrylate (PEGMA) phantom. Consequently, the results demonstrated that the proposed system could generate appropriate plan and manipulate an ultrasound transducer on body surface considering contact condition with body surface.
{"title":"Hybrid position/force control system of the ultrasonic treatment device by parallel-link robot","authors":"Kaoru Natsume, S. Irisawa, S. Onogi, T. Mochizuki, K. Masuda","doi":"10.11239/JSMBE.53.21","DOIUrl":"https://doi.org/10.11239/JSMBE.53.21","url":null,"abstract":"Microbubbles are widely used as contrast agents in ultrasound diagnosis. Microbubbles may also has therapeutic uses in the heat amplification of high-intensity focused ultrasound ablation or as carriers of acoustic targeted drug gene delivery therapy. However, microbubbles injected into a blood vessel are diffused throughout the whole body ; therefore, their efficiency is still limited. If microbubbles could be controlled in vivo, their efficiency and efficacy would be significantly improved. To address this issue, we have proposed a technique that controls microbubble behavior in blood vessels using ultrasound emitted from the body surface. To apply the technique in vivo, robotic ultrasound transducer positioning on body surface is required. For this purpose, we have developed a robotic system and confirmed that microbubble can be manipulated by the system. In more practical condition, focal length of an ultrasound transducer has to be considered. To address the issue, we propose a control system considering the focal length in this study. The system consists of a parallel-link robot for ultrasound transducer positioning, a robot controller, and an optical tracking device. The robot has three arms, and a transducer holder, and a six-axis force sensor. The robot controller generates ultrasound emission plans using body surface position measured by the tracking device, and manipulate the robot. As for validation of the system, we performed following experiments ; 1) positioning accuracy evaluation without contact, 2) evaluation of contact forces control, and 3) in vitro ultrasound emission tests. From the first experiment, positioning accuracy was less than 1 mm. As for the contact force control validation, the system could keep required reaction force for ultrasound emission on a phantom surface within 1.5 mm errors. In the third experiment, the errors in the perpendicular direction of the ultrasound axis and the direction of the axis were 0.71 mm and 5.52 mm, respectively. From the results, we confirmed that the system could emit ultrasound to a target by using a hydrophone in a poly(ethylene glycol) monomethacrylate (PEGMA) phantom. Consequently, the results demonstrated that the proposed system could generate appropriate plan and manipulate an ultrasound transducer on body surface considering contact condition with body surface.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81169215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toi Sawaguchi, N. Hosaka, R. Koda, S. Onogi, T. Mochizuki, K. Masuda
We previously reported our attempts to increase local concentration of microbubbles in water flow by acoustic radiation force, with the aim to apply to ultrasound therapy. Because the actual blood vessels are generally structurally complex and contain multiple bifurcations, trapping microbubbles in multiple areas will improve total therapeutic efficiency. However, there is a limitation to the number of ultrasound transducers that can be placed on the body surface, since a single-element transducer produces only one focal point. In this study, we developed a method to trap microbubbles (bubble liposome) that may contain various kinds of drugs in multiple areas by designing a time-shared acoustic field produced by a 2D array transducer at a frequency of 1 MHz. First, we conducted an experiment to trap microbubbles in a straight path of an artificial blood vessel to investigate the relationship between the trapped area and ultrasound parameters. Next, we conducted an experiment to produce a time-shared acoustic field under optimal conditions : maximum sound pressure of 150 kPa-pp and duty ratio of 25% in ultrasound emission. Under these conditions, we succeeded in trapping microbubbles simultaneously in four individual parallel paths with inner diameter of 0. 7 mm, in a multibifurcated artificial blood vessel model. We also measured the area of trapped microbubbles under a continuous wide acoustic field that covered the area of four paths. Using the same ultrasound power, the time-shared acoustic field had improved trapping efficiency compared to the continuous acoustic field.
{"title":"Experimental Study to Improve Local Trapping Efficiency of Microbubbles by Time-shared Emission of Three-dimensional Acoustic Field","authors":"Toi Sawaguchi, N. Hosaka, R. Koda, S. Onogi, T. Mochizuki, K. Masuda","doi":"10.11239/JSMBE.53.179","DOIUrl":"https://doi.org/10.11239/JSMBE.53.179","url":null,"abstract":"We previously reported our attempts to increase local concentration of microbubbles in water flow by acoustic radiation force, with the aim to apply to ultrasound therapy. Because the actual blood vessels are generally structurally complex and contain multiple bifurcations, trapping microbubbles in multiple areas will improve total therapeutic efficiency. However, there is a limitation to the number of ultrasound transducers that can be placed on the body surface, since a single-element transducer produces only one focal point. In this study, we developed a method to trap microbubbles (bubble liposome) that may contain various kinds of drugs in multiple areas by designing a time-shared acoustic field produced by a 2D array transducer at a frequency of 1 MHz. First, we conducted an experiment to trap microbubbles in a straight path of an artificial blood vessel to investigate the relationship between the trapped area and ultrasound parameters. Next, we conducted an experiment to produce a time-shared acoustic field under optimal conditions : maximum sound pressure of 150 kPa-pp and duty ratio of 25% in ultrasound emission. Under these conditions, we succeeded in trapping microbubbles simultaneously in four individual parallel paths with inner diameter of 0. 7 mm, in a multibifurcated artificial blood vessel model. We also measured the area of trapped microbubbles under a continuous wide acoustic field that covered the area of four paths. Using the same ultrasound power, the time-shared acoustic field had improved trapping efficiency compared to the continuous acoustic field.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83832227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Because touch is a mechanical interaction between the skin and an object, unconstrained tactile sensing is a challenging issue. In this research we studied spatial transparency, a new concept in unconstrained tactile sensing that allows collection of tactile information without affecting the touch conditions. Especially, we aimed at developing a spatially transparent tactile sensor that detects touch information with high dynamic range from any part of the body. For the development of such sensors, this report focuses on the electromechanical properties of the skin, particularly elasticity and conductivity, and proposes a novel tactile sensor based on measurement of the electrical contact impedance between the skin and an object. The measurement of skin contact impedance is achieved using a grounding electrode and two signal electrodes attached to any part of the body. We investigated the relationship between touch force and output of the proposed sensor using a force sensor. The experimental results indicate that the proposed sensor functions adequately as an unconstrained tactile sensor, and confirm that the proposed sensing system has an excellent dynamic range.
{"title":"Spatially Transparent Tactile Sensor Utilizing Electromechanical Properties of Skin (Special Editorials : Five Selected Articles in ABE)","authors":"Shunsuke Yoshimoto, Yoshihiro Kuroda, M. Imura","doi":"10.14326/ABE.1.89","DOIUrl":"https://doi.org/10.14326/ABE.1.89","url":null,"abstract":"Because touch is a mechanical interaction between the skin and an object, unconstrained tactile sensing is a challenging issue. In this research we studied spatial transparency, a new concept in unconstrained tactile sensing that allows collection of tactile information without affecting the touch conditions. Especially, we aimed at developing a spatially transparent tactile sensor that detects touch information with high dynamic range from any part of the body. For the development of such sensors, this report focuses on the electromechanical properties of the skin, particularly elasticity and conductivity, and proposes a novel tactile sensor based on measurement of the electrical contact impedance between the skin and an object. The measurement of skin contact impedance is achieved using a grounding electrode and two signal electrodes attached to any part of the body. We investigated the relationship between touch force and output of the proposed sensor using a force sensor. The experimental results indicate that the proposed sensor functions adequately as an unconstrained tactile sensor, and confirm that the proposed sensing system has an excellent dynamic range.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81903549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many useful signals measured on the body surface contain DC and extremely low frequency components. However, surface electrodes are not ideal for DC or low frequency signal measurements because the electrochemical interaction between the body and the metal contact is unstable. We propose a substantial technique to improve DC stability for biological potential measurements on the body surface, by which unstable fluctuations are canceled by a discharging switch. The system alternates between two states. In the discharging state, two electrodes are connected to each other by an analog switch and the randomly generated charge on the electrodes is canceled. When the switch is turned off. the differential voltage is sampled and stored. The sampling frequency of the system is equal to the switching frequency because of this procedure. An experiment employing Ag/AgCl surface electrodes on human skin showed that DC shift and fluctuation were reduced to 1/4 and 1/6 or less, respectively, of the values without the canceler. Applying this technique to electrooculogram measurement, we found that absolute visual direction could be detected without major baseline drift.
{"title":"A Baseline Drift Canceler Using Discharging Chopper for Surface Metal Electrodes (Special Editorials : Five Selected Articles in ABE)","authors":"M. Kyoso, J. Midorikawa, Y. Shimatani","doi":"10.14326/ABE.1.3","DOIUrl":"https://doi.org/10.14326/ABE.1.3","url":null,"abstract":"Many useful signals measured on the body surface contain DC and extremely low frequency components. However, surface electrodes are not ideal for DC or low frequency signal measurements because the electrochemical interaction between the body and the metal contact is unstable. We propose a substantial technique to improve DC stability for biological potential measurements on the body surface, by which unstable fluctuations are canceled by a discharging switch. The system alternates between two states. In the discharging state, two electrodes are connected to each other by an analog switch and the randomly generated charge on the electrodes is canceled. When the switch is turned off. the differential voltage is sampled and stored. The sampling frequency of the system is equal to the switching frequency because of this procedure. An experiment employing Ag/AgCl surface electrodes on human skin showed that DC shift and fluctuation were reduced to 1/4 and 1/6 or less, respectively, of the values without the canceler. Applying this technique to electrooculogram measurement, we found that absolute visual direction could be detected without major baseline drift.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84201255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Specialized languages used for describing computational models in the field of systems biology and physiology, such as Systems Biology Markup Language (SBML), CellML, and Physiological Hierarchy Markup Language (PHML), have been devised to enhance effective model reuse and sharing among researchers for developing large, multilevel models. Each language has its own specialty. By combining two of these languages, i. e. SBML for illustrating subcellular phenomena and PHML for expressing supracellular dynamics, a novel technology has been developed to describe models of multilevel biophysiological systems. For practical use of the aforementioned languages, consolidated software applications providing intuitive graphical user interfaces are necessary. Starting from 2011, a versatile platform called PhysioDesigner has been developed for multilevel modeling of physiological systems based on PHML. In this article, we focus on the newly developed distinguishing features of PhysioDesigner and PHML for the development of multilevel biophysiological models using SBMLPHML hybridization.
{"title":"A Versatile Platform for Multilevel Modeling of Physiological Systems : SBML-PHML Hybrid Modeling and Simulation (Special Editorials : Five Selected Articles in ABE)","authors":"Y. Asai, T. Abe, H. Oka","doi":"10.14326/ABE.3.50","DOIUrl":"https://doi.org/10.14326/ABE.3.50","url":null,"abstract":"Specialized languages used for describing computational models in the field of systems biology and physiology, such as Systems Biology Markup Language (SBML), CellML, and Physiological Hierarchy Markup Language (PHML), have been devised to enhance effective model reuse and sharing among researchers for developing large, multilevel models. Each language has its own specialty. By combining two of these languages, i. e. SBML for illustrating subcellular phenomena and PHML for expressing supracellular dynamics, a novel technology has been developed to describe models of multilevel biophysiological systems. For practical use of the aforementioned languages, consolidated software applications providing intuitive graphical user interfaces are necessary. Starting from 2011, a versatile platform called PhysioDesigner has been developed for multilevel modeling of physiological systems based on PHML. In this article, we focus on the newly developed distinguishing features of PhysioDesigner and PHML for the development of multilevel biophysiological models using SBMLPHML hybridization.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83673638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigated the effects of forced response-like movements on serial reversal learning of a sensorimotor task in normal and hemiplegic (unilateral cortical lesion in the forepaw sensorimotor area) rats. The rats were trained to respond to an air-puff stimulus applied to one forepaw; the response involved releasing either the stimulated or non-stimulated forepaw from a lever. During the training, an error trial was followed by a correction trial wherein a lever on the correct-response side (n=4 in each group) or the incorrect-response side (n=4 in each group) was automatically elevated at 220 ms after the air-puff stimulation, mimicking the ratsʼ lever-release movement. No lever activation was applied to the rats in the control condition (n=4 in each group). We found that learning speed was generally facilitated by the lever activation procedure on the incorrectresponse side, but not on the correct-response side. As an exception, however, lever activation on the correctresponse side facilitated learning in the contralesional (paralyzed side) forepaw of the hemiplegic group. Reaction time was not affected by the lever activation procedure, although it was longer for the contralesional forepaw compared to the ipsilesional forepaw in the hemiplegic group and both forepaws in the normal group. We conclude that the sensory inputs induced by the same forced response-like movement facilitate learning or rehabilitation differently in normal and hemiplegic rats. The results and the animal model in this study are useful for the development of more efficient motion-assisting devices for rehabilitation.
{"title":"Facilitation of Learning and Rehabilitation in Rats by Inducing Response-like Movement (Special Editorials : Five Selected Articles in ABE)","authors":"Hiroto Sano, H. Kaneko, Y. Hasegawa","doi":"10.14326/ABE.2.72","DOIUrl":"https://doi.org/10.14326/ABE.2.72","url":null,"abstract":"We investigated the effects of forced response-like movements on serial reversal learning of a sensorimotor task in normal and hemiplegic (unilateral cortical lesion in the forepaw sensorimotor area) rats. The rats were trained to respond to an air-puff stimulus applied to one forepaw; the response involved releasing either the stimulated or non-stimulated forepaw from a lever. During the training, an error trial was followed by a correction trial wherein a lever on the correct-response side (n=4 in each group) or the incorrect-response side (n=4 in each group) was automatically elevated at 220 ms after the air-puff stimulation, mimicking the ratsʼ lever-release movement. No lever activation was applied to the rats in the control condition (n=4 in each group). We found that learning speed was generally facilitated by the lever activation procedure on the incorrectresponse side, but not on the correct-response side. As an exception, however, lever activation on the correctresponse side facilitated learning in the contralesional (paralyzed side) forepaw of the hemiplegic group. Reaction time was not affected by the lever activation procedure, although it was longer for the contralesional forepaw compared to the ipsilesional forepaw in the hemiplegic group and both forepaws in the normal group. We conclude that the sensory inputs induced by the same forced response-like movement facilitate learning or rehabilitation differently in normal and hemiplegic rats. The results and the animal model in this study are useful for the development of more efficient motion-assisting devices for rehabilitation.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86489817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hypoxia-related mechanisms are important in tumor biology and immune responses. Oxygen is delivered to tumor tissue by blood flowing through abnormal and dysfunctional microvessels, resulting in heterogeneity of tissue oxygenation within the tumor. Hypoxic conditions play a role in directing angiogenesis, guiding immune cells, and inducing tumor metastasis. Mimicking such oxygen gradient in in vitro cellular experiments is important to clarify the mechanisms involved in tumor biology. Previous research has led to the development of cell culture devices that generate an oxygen gradient, but it was impossible to monitor the oxygen gradient during cell culture. In this study, we designed an open-well polydimethylsiloxane (PDMS) microfluidic device integrated with an oxygen-sensitive film, which permits oxygen measurement around cells and molecular analysis after cell culture experiments. Mathematical simulation and phosphorescence-based partial oxygen measurements show that the gradient can be controlled by changing the oxygen gas concentration inside the microchannels, according to the requirements of various biological models. A monoculture of endothelial cells exposed to an oxygen gradient in the device showed increased expression of oxygen-responsive genes in the hypoxic area. These results suggest that our microfluidic device can be used for in vitro experiments such as gene expression and migration assays. We believe that this new device is a powerful tool for studies of tumor biology and immunology.
{"title":"Generation of an Oxygen Gradient in a Microfluidic Device and Cellular Analysis in Hypoxia (Special Editorials : Five Selected Articles in ABE)","authors":"Hideyuki Uchida, Asako Sato, A. Miyayama","doi":"10.14326/ABE.2.143","DOIUrl":"https://doi.org/10.14326/ABE.2.143","url":null,"abstract":"Hypoxia-related mechanisms are important in tumor biology and immune responses. Oxygen is delivered to tumor tissue by blood flowing through abnormal and dysfunctional microvessels, resulting in heterogeneity of tissue oxygenation within the tumor. Hypoxic conditions play a role in directing angiogenesis, guiding immune cells, and inducing tumor metastasis. Mimicking such oxygen gradient in in vitro cellular experiments is important to clarify the mechanisms involved in tumor biology. Previous research has led to the development of cell culture devices that generate an oxygen gradient, but it was impossible to monitor the oxygen gradient during cell culture. In this study, we designed an open-well polydimethylsiloxane (PDMS) microfluidic device integrated with an oxygen-sensitive film, which permits oxygen measurement around cells and molecular analysis after cell culture experiments. Mathematical simulation and phosphorescence-based partial oxygen measurements show that the gradient can be controlled by changing the oxygen gas concentration inside the microchannels, according to the requirements of various biological models. A monoculture of endothelial cells exposed to an oxygen gradient in the device showed increased expression of oxygen-responsive genes in the hypoxic area. These results suggest that our microfluidic device can be used for in vitro experiments such as gene expression and migration assays. We believe that this new device is a powerful tool for studies of tumor biology and immunology.","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90249474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuya Natsume, T. Namita, Y. Kato, M. Kitama, K. Shimizu
{"title":"Development of management technique of arteriovenous fistula in hemodialysis by optical transillumination imaging with measured point spread function","authors":"Yuya Natsume, T. Namita, Y. Kato, M. Kitama, K. Shimizu","doi":"10.11239/JSMBE.52.O-126","DOIUrl":"https://doi.org/10.11239/JSMBE.52.O-126","url":null,"abstract":"","PeriodicalId":39233,"journal":{"name":"Transactions of Japanese Society for Medical and Biological Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80050322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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