We developed a new artificial placenta (AP) system consisting of a loop circuit configuration extracorporeal membrane oxygenation (ECMO) with a bridge circuit designed to be applied to the fetus in ...the form of an umbilical arterial–venous connection. We aimed to evaluate the feasibility of the AP system by performing a hydrodynamic simulation using a mechanical mock circulation system and fetal animal experiment. The effect of the working condition of the AP system on the fetal hemodynamics was evaluated by hydrodynamic simulation using a mechanical mock circulation system, assuming the weight of the fetus to be 2 kg. The AP system was introduced to two fetal goats at a gestational age of 135 days. The general conditions of the experimental animals were evaluated. The mock simulation showed that in an AP system with ECMO in the form of an umbilical arterial–venous connection in series, it could be difficult to maintain fetal hemodynamics when high ECMO flow was applied. The developed AP system could have high ECMO flow with less umbilical blood flow; however, the possibility of excessive load on the fetal right-sided heart should be noted. In the animal experiment, kid 1 (1.9 kg) was maintained on the AP system for 12 days and allowed to grow to term. In kid 2 (1.6 kg), the AP system could not be established because of the occlusion of the system by a thrombus. The developed AP system was feasible under both in vitro and in vivo conditions. Improvements in the AP system and management of the general fetal conditions are essential.
Food texture is one of the characteristics of food and is an important factor in food development. In this paper, a method of food texture quantification based on expressions for texture instead of ...physical properties is proposed. The method obtains two sets of time-series data of force and vibration during food compression using a magnetic food texture sensor. Dynamic time warping (DTW) matches the time-series data and standard data and calculates the degree of texture similarity. The standard data are determined by DTW barycenter averaging (DBA). The experimental results for tempura showed that the degree of texture similarity based on the vibration data had a strong correlation with the sensory evaluation data.
In the modern society with a variety of information electronic devices, human interfaces increase their importance in a boundary of a human and a device. In general, the human is required to get used ...to the device. Even if the device is designed as a universal device or a high-usability device, the device is not suitable for all users. The usability of the device depends on the individual user. Therefore, personalized and customized human interfaces are effective for the user. To create customized interfaces, we propose rapid prototyping human interfaces using stretchable strain sensors. The human interfaces comprise parts formed by a three-dimensional printer and the four strain sensors. The three-dimensional printer easily makes customized human interfaces. The outputs of the interface are calculated based on the sensor’s lengths. Experiments evaluate three human interfaces: a sheet-shaped interface, a sliding lever interface, and a tilting lever interface. We confirm that the three human interfaces obtain input operations with a high accuracy.
Crispness contributes to the pleasantness and enjoyment of eating foods and is popular with people of wide ages in many countries. Hence, a quantitative evaluation method for crispness is required ...for food companies developing new food products. In this study, the effects of different sensory combinations on crispness were investigated through sensory evaluation, and a Gaussian process regression model was used to predict the evaluation values of crispness. First, four crispness descriptors in Japanese were selected, and sensory evaluations were conducted with ten participants using commercially available snack foods under three different sensory combinations of force, vibration, and sound to confirm the effects of the three senses. An instrumental system also measured force, vibration, and sound for snack foods under the same conditions. The Gaussian process regression model determined the relationship between the sensory and measurement data and predicted the sensory evaluation values from the measurement data. Cross-validation verified that the Gaussian process regression model accurately predicted the food texture evaluation values from the measurement data even in conditions with different sensory components.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The human is covered with soft skin and has tactile receptors inside. The skin deforms along a contact surface. The tactile receptors detect the mechanical deformation. The detection of the ...mechanical deformation is essential for the tactile sensation. We propose a magnetic type tactile sensor which has a soft surface and eight magnetoresistive elements. The soft surface has a permanent magnet inside and the magnetoresistive elements under the soft surface measure the magnetic flux density of the magnet. The tactile sensor estimates the displacement and the rotation on the surface based on the change of the magnetic flux density. Determination of an estimate equation is difficult because the displacement and the rotation are not geometrically decided based on the magnetic flux density. In this paper, a stepwise regression analysis determines the estimate equation. The outputs of the magnetoresistive elements are used as explanatory variables, and the three-axis displacement and the two-axis rotation are response variables in the regression analysis. We confirm the regression analysis is effective for determining the estimate equations through simulation and experiment. The results show the tactile sensor measures both the displacement and the rotation generated on the surface by using the determined equation.
Flexible and stretchable strain sensors are expected to significantly contribute to new technologies and be applied in various applications, including human interfaces, smart clothes, and robotic ...skin. Hence, we have proposed a flexible film-shaped strain sensor that is composed of three elastomer films and two carbon-nanotube electrodes. It is thin, lightweight, and has low elasticity. Strain measurements taken by the sensor are based on changes in capacitance, which is proportional to the square of the area of the sensor's sensing part. Consequently, the capacitance of the strain sensor does not show the direction of the strain. As some applications require the measurement of strain in a fixed direction, this paper proposes an anisotropic strain sensor. This anisotropic strain sensor decreases the effect of the strain in the fixed direction to less than 10%. The model of the anisotropic strain sensor and experimental results show that its capacitance is proportional to the square of the length of the sensing part in the stretch direction. To check the anisotropic strain sensor's practicality, it is applied to estimate the angle of a wrist joint. The results show that the anisotropy decreases the root-mean-square error of the estimated angle to less than 3°.
In mastication, humans perceive three types of stimuli: taste, aroma, and texture. Among the three types of stimuli, the texture is generated by physical factors and has a significant influence on ...preference. Therefore, food development needs to design and evaluate the texture. Currently, there are two types of texture evaluation: sensory evaluation and evaluation using measurement devices. Sensory evaluation has the disadvantages that individual differences cannot be ignored and that data acquisition is costly. To solve these disadvantages, studies on quantitative evaluation of texture by food measurement device has been conducted. It has been reported that texture can be evaluated in detail by using sensors with different application characteristics for texture evaluation using measuring devices. The texture profile analysis extracts feature values from force data as a standard evaluation method. This study measured three data that were used for texture evaluation: force, vibration, and sound. The Gaussian process regression determines the relationship between the measurement data and sensory evaluation data. In an experiment, seven kinds of snack foods were measured. Feature values were calculated from the measurement data. The Gaussian process regression estimated the sensory evaluation values. This study also focused on the effectiveness of the sound data for the estimation. The experimental data indicated that the three measurement data including the sound data contributed to lower errors of the texture estimation.
Active touch with voluntary movement on the surface of an object is important for human to obtain the local and detailed features on it. In addition, the active touch is considered to enhance the ...human spatial resolution. In order to improve dexterity performance of multifinger robotic hands, it is necessary to study an active touch method for robotic hands. In this paper, first, we define four requirements of a tactile sensor for active touch and design a distributed tactile sensor model, which can measure a distribution of compressive deformation. Second, we suggest a measurement process with the sensor model, a synthesis method of distributed deformations. In the experiments, a five-finger robotic hand with tactile sensors traces on the surface of cylindrical objects and evaluates the diameters. We confirm that the hand can obtain more information of the diameters by tracing the finger.
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