著者

小島 輝明 高本 俊一 森岡 賢次 山本 晋平 綿貫 雅也 長谷川 光彦 三宅 仁 塩野谷 明

出版者

Society of Biomechanisms

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.16, pp.231-241, 2002

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It is effective to determine running pace in advance, based on individual ability, in order to demonstrate the highest performance in long-distance running. The evaluation indices for a long-distance runner are maximum oxygen uptake, lactate threshold (LT), and ventilatory threshold (VT). These, however, are mostly used stastistically, so results may differ from real ability in a personal equation.<BR>The purposes of this study were to construct an energy-metabolism model and to optimize the running pace of long-distance running using a genetic algorithm (GA). The energy-metabolism model constructed in the study was composed of an anaerobic energy feeder structure, an aerobic energy feeder structure, and the section to be run. These elements were expressed as differential equations and restricted inequality formulas. The running speed for each subject, calculated from the best time for 300 meters, the amount of oxygen uptake, and running speed at the VT in each subject were used as parameters for the energy-metabolism model.<BR>VT was measured by a gradually increasing speed exercise using a treadmill because it was difficult to measure during field running. There are many differences between treadmill running and field running, however. In this study, the subject ran continuously on a treadmill with traction to his back using a rubber tube. The running speed for treadmill running was adjusted to that in field running based on heart rate.<BR>The energy-metabolism model had two controlled variables, and running speed could be controlled by these variables. We tried to optimize the energy-metabolism model by determining the two controlled variables using a GA. The spurt start point was also determined during optimization. The GA determined the spurt start point based on the energy-metabolism model.<BR>The running speed in 5000-meter races was optimized as follows: (1) speed ascends immediately after the start of the race, and then descends by a constant degree; (2) speed ascends again at 1000 to 1400 meters before the goal; and (3) almost 1 minute later, running goes to maximum speed then descends again by a constant degree all the way to the goal. This optimization result corresponded closely to the actual racing of the subject, who trained for improved ability in long-distance running.

著者

國澤 尚子 新村 洋未 小川 鑛一

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.17, pp.195-205, 2004 (Released:2005-04-15)

参考文献数

6

被引用文献数

1

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The objectives of the current research were to clarify differences in beginners' and nurses' techniques for manipulation of a syringe and to propose methods of education for mastering quick and accurate techniques. In this paper, differences in techniques for manipulation of a syringe by nursing students and nurses are discussed from two perspectives. One is the effects of combining the syringe and injection needle in terms of the pressure in the syringe. The other is differences in methods of grasping the syringe. Based on these results, problems relating to adjustment of the force used by a nurse to manipulate a syringe and contact of the fingertip with the plunger become apparent.For measurement of the pressure in the syringe, a processed syringe is connected to a strain gauge type of force conversion device and strain is converted to pressure. For pressing of the plunger, hypodermic injection and extrusion of a drug solution into a vial were performed. For drawing of the plunger, collection of blood and suctioning from a plastic ampule were performed.With regard to pressure in the syringe, the maximum gauge pressure was large for a finer injection needle when the syringe was the same size in all techniques for nursing students as well as nurses. In simulated hypodermic injection, nursing students had a larger maximum gauge pressure with a larger syringe with the same injection needle. However, nurses considered the effects on the body and adjusted force so that the maximum gauge pressure did not increase. Because extrusion from a syringe and suctioning from an ampule are techniques that do not insert a needle in the body, nurses added substantial force and manipulated the syringe in a short period of time. In addition, limits for the addition of force were also considered.Based on classification of patterns of waveforms with regard to drawing of the plunger in suctioning from an ampule, nursing students often had multiple valley-shaped waveforms. Patterns produce waveforms like this because the syringe is passed from hand to hand. Differences in the appearance of waveforms due to the size of the syringe were noted for nurses, indicating separate use of methods of manipulating a syringe plunger as needed.With regard to the grasping of a syringe, nursing students grasp it so as not place their fingertip in contact with the plunger. This is because they are taught in class not to make contact with the plunger based on the perspective of preventing infection. However, a majority of nurses make contact with the plunger when drawing the plunger. That is, making contact with the plunger for drawing of the plunger is a technique in which the plunger is easy to manipulate. Nurses may have adopted an efficient method in clinical settings. Even if the stance that contact with the plunger should be avoided to prevent infection is learned, making contact with the plunger as experience is acquired leads one to conclude that education in techniques for manipulation of injections is vague. Having nurses change the techniques they have acquired is difficult, so sterile gloves should be worn as a general rule when manipulating a syringe.In the future, force added to the suction head of a syringe plunger will be measured and the relationship with internal pressure will be verified.

著者

青木 慶 山崎 信寿 井上 剛伸 山崎 伸也 三田 友記

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.17, pp.217-226, 2004 (Released:2005-04-15)

参考文献数

9

被引用文献数

2 1

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This paper describes the optimization of hip joint characteristics of a hip disarticulation prosthesis. We attempted to optimize the characteristics for improved ability to walk using our passive walking model, which can walk by utilizing mechanical properties of rigid body segments and joint resistance.In order to understand how the hip disarticulation prosthesis gait is performed, we interviewed two hip disarticulation prosthesis users. The interviews showed that practical gait in daily life is different from the gait at a training stage. These two types of gaits were named “practical gait” and “training gait.” Users indicated that the training gait velocity was slower than that of the practical gait. Moreover, in the practical gait the heel contact on the prosthesis side was more natural in comparison with the training gait.Gait measurements showed that the lumbar angle pattern has rapid extension and lateral bending involving the swing prosthesis in training gait. Step length on the sound side is in agreement despite the different types of gait. In practical gait, step length on the sound side agrees with that on the prosthesis side. Gait velocity in practical gait compared with training gait was 28% faster with subject 1 and 7% faster with subject 2. Therefore, practical gait has an improved gait velocity by swinging the prosthesis, as step length on each side is the same. Motion of prosthesis is achieved not by sound lower extremities but by lumbar flexion, extension, and lateral bending. Furthermore, practical gait reduces lumbar motion as much as possible, and reduces muscle force around the lumbar area.We developed a passive swing model by applying the above characteristics. This model is composed of eight rigid segments: upper torso, pelvis, upper extremities, thigh, shank-foot. Each joint has passive resistance by ligament. The sound hip and lumbar joint have active moments by muscle, which were obtained from measurement. The objective function for practical gait is defined by the following parameters: (1) difference of each step length, (2) amplitude of active moments, (3) difference of cycles between gait patterns and active moments. As these parameters are minimized, postures of segments, translational velocity, angular velocities and cycle, and amplitude of active moment are recorded. In comparison of subjects, calculated motion patterns on the prosthesis side were well in agreement, so this model is available to estimate hip joint characteristics.When this model simulates a condition of the current hip elastic characteristic weakened by half, the gait velocity is 6% faster and amplitude of lumbar lateral bending moment is reduced 26%. For this reason, weakening current elastic characteristics around the hip joint can easily control the swing of the prosthesis. As a result, adjustment of the hip elastic characteristic can improve the walk capability.

著者

山田 宏 松村 仁 森田 大作

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.17, pp.173-184, 2004 (Released:2005-04-15)

参考文献数

17

被引用文献数

1 1

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This theoretical investigation of the mechanics of the vascular endothelial cells that line the luminal side of blood vessels focused on two points. First, we formulated a hypothesis on the orientation of stress fibers, i.e., bundles of actin filaments, under cyclic deformation, and used numerical simulation to predict their orientation under various types of substrate deformation. Second, we created a finite element model of cultured endothelial cells adhering to a substrate, i.e., a silicone membrane, and a vascular endothelial cell on the luminal side of a vascular wall, and used finite element analyses to determine the stress and strain under various types of deformation.To predict the orientation of stress fibers, we hypothesized that they are oriented only in the direction in which the strain component in the fiber direction does not exceed the strain limit, either with maximum deformation of the substrate or during deformation of the substrate. We found that stress fibers have a minimum length during the process of substrate stretching, and investigated the importance of considering substrate deformation during cyclic stretching. The numerical simulation showed that the effect is small over the physiological range of cyclic deformation experienced in blood vessels. We also predicted the out-of-plane orientations of stress fibers during cycles of simple elongation, pure uniaxial stretching, and equibiaxial stretching. With cyclic equibiaxial stretching and the assumption of a certain cell height, the predicted orientation of stress fibers agreed with the reported range of orientation of the actin cytoskeleton.Second, using finite element modeling and analyses, we modeled a cell adherent to a substrate and a vascular endothelial cell on the luminal side of the vascular wall. We assumed that a cell consists of a nucleus and cytoplasm, and that both are incompressible, isotropic, hyperelastic materials. We also assumed that the bottom surface of the cell completely attaches to the substrate surface. The analyses of the stress and strain in the cell showed that the strain was greatest at the substrate and decreased in higher positions in the cell; the amount of strain in the top region of the cell depended on its shape. Moreover, the existence of the nucleus caused a complicated distribution of stress and strain in the cytoplasm. This result provides important information for predicting the orientation of stress fibers with nonuniform deformation of a cell.

著者

中村 康雄 林 豊彦 中村 真里 建道 寿教 信原 克哉 菊入 大輔 桐生 慎哉

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.17, pp.111-121, 2004 (Released:2005-04-15)

参考文献数

17

被引用文献数

1 1 2

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Diagnosis of a shoulder joint injury, particularly one brought about during sports activities, necessitates measurement of its motion accurately and noninvasively. Conventional measurement of shoulder joint movement, however, deals solely with relative movement between humerus and thorax, neglecting other components of the joint. We have focused on 6-DOF measurement of scapula movement relative to the thorax, a subdominant component of shoulder movement. Such motion data, however, cannot easily be obtained by means of a marker-based motion-capture system, due to the skin mobility relative to the skeleton. The objective of this study was to validate measurement accuracy of scapula movement when measuring markers are attached to the skin above the scapula’s bony landmarks.We employed an open MRI (Magnetom Open, Siemens, Germany) to measure the shoulder joint and markers attached to the subject’s skin. Five and three markers were attached to the skin above the scapula and thorax, respectively. Three volunteers (24.0±2.64 years old), who possessed no distinct kinetic dysfunctions in their shoulders, served as subjects, in this preliminary study. Their shoulder movements were sampled at three humeral elevation angles (0°, 90°, 150°) on a frontal plane by open MRI. In order to reduce the skin mobility, the same movements were recorded, using a more accurate method in which the scapula’s markers were relocated into correct positions, determined through the palpation of an experienced physical therapist, at each humeral elevation. In an attempt to validate the skin mobility, we measured the deviation of the markers from the scapula’s bony landmarks during humeral elevation. Next, the scapula movements were estimated by two different methods as follows: the registration technique using bony shape and the least squares method using the set of markers.The results demonstrated that the deviation of the markers could be reduced into less than or equal to 19.0 mm if the markers were remounted at each elevation angle. Using the remounted markers, we verified the estimated error of position and orientation of the scapula to lie within 10.1° and 6.4 mm, respectively.In conclusion, we validated measurement accuracy of the scapula movement using skin markers above the scapula’s bony landmarks. The results showed that a motion-capture system is capable of quantitatively measuring the static shoulder joint movement with the scapula.

著者

大西 謙吾 宮川 浩臣 田島 孝光 斎藤 之男

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.16, pp.155-165, 2002 (Released:2004-09-01)

参考文献数

22

被引用文献数

1

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Demand for fine human function modeling methodology is rising with the popularization of assistive devices. Systems engineering based research that delves into the functional cooperative relationship of the digits, hand, and arm is needed for design of substitutive mechanisms and for their control of the human body. The optimal tool for such research is the design process of a sensor-based robotic hand-arm system. This paper discusses the research issues and our proposed strategy.Our research goal is to develop a sensory-controlled mechanical system for performing versatile human-like prehension. As a design concept, we propose an effective model extracted from functional analysis of the upper limb. The key assumption in categorizing hand behavior is the arm’s driving function. Without proper integration of the two, the hand function can be neither analyzed nor assembled. Our approach uses this assumption as its base; we propose a method for classifying a non-redundant relation to control the dynamic and static use of the artificial upper limb.We began remodeling the degrees of freedom (DOF) of the human hand by identifying the transverse and longitudinal adjustable arch structure in the hand. Our new model is composed of 21 active DOF, which include movement in the palm. We classified movements and postures of the hand and arm with this DOF model located at the end of a seven-DOF arm. We then classified the hand modes as prehensile forms and sustentacular forms.Based on this model and our previous research experience in developing prosthetic upper limbs and anthropomorphic robotic hands, we devised a robotic hand-arm with a total of 24 degrees of freedom. Additionally, a new multitactile sensor has been developed for use on the robotic hands in our laboratory at TDU.For generating control strategy, the behavior of the hand is classified into two divisions. The first is cooperation of the digits and palm, and the second is cooperation of the hand and arm modules. The digit cooperation task is fourfold: formation, transformation, deformation, and hold. A motion planner drives the digit movements from the relation of the hand forms to the task that is proposed.A tactile sensor-based control strategy is presented. The digits are controlled according to the hand modes and the sensory feedback loop, with slippage detection rules. Two strategies are proposed for extending the control for fine manipulation: cooperative slippage sensing of adjacent digits, and slippage prediction applying hand orientation information measured by an inclinometer.The overall objective of our approach is the design of a dexterous control system for a multi-DOF robotic upper limb. This includes discussion of a modeling method for the human upper limb.

著者

宮崎 信次

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

no.17, pp.227-234, 2004-08-25

被引用文献数

2 3

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Several mouse emulator devices are commercially available for patients with high-level cervical cord injury (CCI), muscular dystrophy, and rheumatoid arthritis. These include head mounting pointers which linearly convert the 2-dimensional deviation of head motion to the 2-axis movements of the cursor. Limitations of inherent accuracy of the neck movement controllability restrict the use of these pointers to people with a good range of motion of the trunk and neck. Other mouse emulators utilize a miniature 2-dimensional position sensor which can be activated by mouth, then convert the information to the cursor movements. When the transformation is from 2-dimensional deviations to the position of the cursor, a problem similar to the head mounting pointers arises. When the 2-dimensional deviation is converted to the velocity of the cursor, the problem is solved. However, the currently available devices of this last type have other problems, e.g., overshoot and drift of the cursor during no input. The purpose of this study was to develop an inexpensive mouse emulator device utilizing a mini joystick and analog pressure sensor, and to test its clinical utility in shortterm experiments and middle-term field tests conducted by volunteer monitors. The study also aimed to combine this mouse emulator with commercially available automatic Japanese voice recognition software to enable those who cannot use their fingers for striking keyboards. The new mouse emulator, named "Joystick," converts the 2-dimensional angular deviation nonlinearly, i.e., stepwise parabolically, to the velocity of the cursor, and also provides a dead movement zone and automatic tracking of mechanically neutral position to prevent drift of the cursor during a resting state. A thorough investigation was made to find the automatic voice recognition software best suited for the present purpose. Japan IBM's Via Voice with ATOK15 was selected. Four CCI patients and four healthy subjects participated in the short-term evaluation of the device. The first task was to control the movement of the cursor around the monitor, and to drag and drop certain portions of the text. The second task was to activate Word, define text format, input predetermined text, revise it, and store it as a file with a name. The performance of each subject using the new device was compared with the performance of one C4 CCI subject using a conventional mouth stick and a track ball. The results were promising. Twelve volunteer monitors participated in the mid-term field evaluation of the device, and 6 out of 9 monitors wanted to buy the device after the 2- to 4-week monitor period, which proved that the device is useful for a large part of the subject population at which the present study was aimed.