比嘉 昌

BACKGROUND: Correction of coronal plane deformity by osteotomies around the knee is theoretically three-dimensional (3D) and can be associated with changes in other planes. It has been shown that 3D rotational changes are induced by biplanar high tibial osteotomy; however, relevant information in biplanar lateral closed-wedge distal femoral osteotomy (LCW-DFO) has not been reported in literatures. This study aimed to investigate rotational changes in axial and sagittal planes in LCW-DFO using computer-aided design (CAD) simulations. METHODS: LCW-DFO is composed of three cuts: one ascending cut and two transverse cuts. In the simulations, the following geometrical parameters were adopted as factors potentially influencing 3D changes occurring in the osteotomy. The ascending cut angle measured as the angle between the edge of the ascending cut and the edge of the transverse cut in the lateral view, and the ascending cut obliquity measured as the angle corresponding to anterior/posterior inclination of the ascending cut with reference to the posterior condylar tangent line in the axial view. In the analysis, the effects of these bony cut angles on associated rotational changes in the axial and sagittal planes (internal/external rotation and flexion/extension) were calculated. Variation of wedge size ranged from 2 to 8 mm. RESULTS: The degree of the ascending cut obliquity substantially correlated with associated change in the sagittal plane (extension/flexion) while inducing only minimal change in rotation in the axial plane (internal/external rotation). When the osteotomy was made without ascending cut obliquity, the change in knee extension/flexion was minimal for the conditions analyzed while coupled internal rotation of the distal bony segment was induced. CONCLUSIONS: In biplanar LCW-DFO, the ascending cut angle substantially influenced the amount of internal rotation of the distal bony segment with little effect on flexion/extension angles. By contrast, ascending cut obliquity in the axial plane yields an effect on flexion/extension angles and little effect on internal rotation of the distal bony segment.

PURPOSE: Instability and fractures may result from tensioning errors during reverse total shoulder arthroplasty (RTSA). To help understand tension, we measured intraoperative glenohumeral contact forces (GHCF) during RTSA. METHODS: Twenty-six patients underwent RTSA, and a strain gauge was attached to a baseplate, along with a trial glenosphere. GHCF were measured in passive neutral, flexion, abduction, scaption, and external rotation (ER). Five patients were excluded due to wire issues. The average age was 70 (range, 54-84), the average height was 169.5 cm (range, 154.9-182.9), and the average weight was 82.7 kg (range, 45.4-129.3). There were 11 females and 10 males, and thirteen 42 mm and 8 38 mm glenospheres. RESULTS: The mean GHCF values were 135 N at neutral, 123 N at ER, 165 N in flexion, 110 N in scaption, and 205 N in abduction. The mean force at terminal abduction is significantly greater than at terminal ER and scaption (p < 0.05). CONCLUSIONS: These findings could help reduce inappropriate tensioning.

Purpose: The purpose of this study was to analyse the resultant stress induced by joint-line obliquity after HTO for varus knee deformity using a three-dimensional (3D) finite element model analysis. Methods: The geometrical bone data used in this study were derived from commercially available human bone digital anatomy media. The 3D knee models were developed using 3D computer-aided design software. The articular surface was overlaid with a 2-mm-thick cartilage layer for both femoral and tibial condyles. Ligament structures were simulated based on properties reported in previous anatomical studies. Regarding the loading condition, isolated axial loads of 1200 N with lateral joint-line inclinations of 2.5°, 5°, 7.5°, and 10° in reference to the horizontal axis were applied to the femur to simulate the mechanical environment in a knee with joint-line obliquity. Results: A steep rise of shear stress in the medial compartment was noted in the model with obliquity of 5° or more. This laterally directed shear stress exhibited an incremental increase in accordance with the obliquity angle. The maximum shear stress value in the medial cartilage increased from 1.6 MPa for the normal knee to 3.3, 5.2, and 7.2 MPa in the joint-line obliquity models with 5°, 7.5°, and 10° of obliquity, respectively. Conclusions: The effects of HTO for varus knee deformity on the amount/distribution of stresses in the articular cartilage were analysed using a 3D finite element model. It was shown that joint-line obliquity of more than 5° induced excessive shear stress in the tibial articular cartilage. A large amount of correction in OWHTO with a resultant joint-line obliquity of 5° or more may induce detrimental stress to the articular cartilage. Double-level osteotomy should be considered as a surgical option in this situation.

Recently, a study to evaluate the optical properties of wearing CL has begun to improve the quality of vision. The soft contact lens (SCL) consists of an optics region, intermediate region and bevel, which improves the wearing feeling mainly. Because soft contact lens is composed of a soft material, it is deformed along the cornea when it is worn on the eye. In the present report, the shape of the commercial SCL is measured firstly by the light-section method. Then, the shape change of wearing SCL is calculated using a finite element method. At the end, influence on the lens diopter of the shape change of the SCL was investigated by CODE V. As a result, the focal length shortened by a shape change of SCL, and in the case of a lens of -6 Diopter, the lens changed than the diopter unit (0.25D) of production.

Recently, a study to evaluate the optical properties of wearing contact lens has begun to improve the quality of vision (QOV). Because soft contact lens (SCL) is composed of a soft material, it deforms along the cornea when it is worn on the eye. Therefore, it is necessary for the study of QOV to develop a method to measure SCL shape of the soft material. In this study, the shape of SCL in a saline was measured by laser slit light. As a result, the measurements became almost same as value of standard of SCL. Front curve and shape of the bevel region which are non-publication were also measured.

<p>It is well known that maximum voluntary torque, produced by skeletal muscles is lower during concentric contraction and higher during eccentric contraction compared with isometric contraction. The steady state property defined by its isometric strength is commonly used. We focus on isometric contraction in detail. The purpose of this study is to measure maximum isometric strength both at active and passive conditions and to examine the condition-related contribution of neural and force mechanics to the force. Six healthy subjects participated in this study. The strength of their elbow flexors and electromyogram (EMG) were measured during the two conditions. As results, the passive condition led to stronger force in maximal isometric significantly while EMG did not show significant changes. In other words, we can sustain stronger force enduring external forces rather than exerting one's maximal voluntary forces against a fixed object.</p>

This study proposes novel optimized stem geometry with low stress values in the cement using a finite element (FE) analysis combined with an optimization procedure and experimental measurements of cement stress in vitro. We first optimized an existing stem geometry using a three-dimensional FE analysis combined with a shape optimization technique. One of the most important factors in the cemented stem design is to reduce stress in the cement. Hence, in the optimization study, we minimized the largest tensile principal stress in the cement mantle under a physiological loading condition by changing the stem geometry. As the next step, the optimized stem and the existing stem were manufactured to validate the usefulness of the numerical models and the results of the optimization in vitro. In the experimental study, strain gauges were embedded in the cement mantle to measure the strain in the cement mantle adjacent to the stems. The overall trend of the experimental study was in good agreement with the results of the numerical study, and we were able to reduce the largest stress by more than 50 % in both shape optimization and strain gauge measurements. Thus, we could validate the usefulness of the numerical models and the results of the optimization using the experimental models. The optimization employed in this study is a useful approach for developing new stem designs.

ソフトコンタクトレンズ（SCL）は光学領域、中間領域および装用感等を担うベベル部から構成されが、軟質材料のSCLを装用すると、眼球に沿って形状が変化して矯正度数に影響を及ぼす。報告では未公開データが多いSCLの形状を測定し、CAD・FEM解析によるSCLの形状変化、およびCODEVによる度数への影響について考察した。

The purpose of this study was to investigate age-related changes in the passive resisting moments at the hip. The changes in the passive resisting moments were hypothesized to occur due to age-related changes in muscle stiffness. Two groups of healthy men participated in this study: young men (approximately 24 years of age) and old men (approximately 68 years of age). Subjects were positioned in a left lateral decubitus position with their left limb supported on a table. With a subject relaxed, an experimenter slowly moved the subject's limb by pulling or pushing the handle attached to the lower limb via a load cell. The subject's hip was moved in passive range of flexion-extension motions. The joint kinematics, measured by a motion capture system, and load cell readings were used to compute the passive resisting moments-joint angle curves at the hip. The passive resisting moments at the hip were found to considerably depend on the adjacent knee angle. The maximal resisting moments, when the hip was extended, were larger for the older group than for the younger group. The measured resisting moments were finally validated against the resisting moments calculated by a musculoskeletal computer model for the same movements. The computer model was able to predict measured tendencies of the moments at the hip. However, further adjustments of the computer model are required to represent the aging effects precisely. © 2014 The Japan Society of Mechanical Engineers.

When the relationship between the dimensions of face form and those of spectacle frames is poor, it may cause problems such as slipping frames and sore areas on the nose and behind the ears. This paper reports the results of mechanically modeling the contact conditions in the vicinity of the nose. We created a CAD model of a human head by considering the skin thickness distribution. We then performed finite element method (FEM) analysis about the contact region between the pad and the skin. As a result, the nose pad is pressed down in the nose while slanting toward the lower part of the nose gently. Furthermore, the pad is fixed by a slight upsurge by the reaction of the imposition of the skin.

Quantifying soft-tissue tension around the hip joint during total hip arthroplasty remains difficult. In this study, a three-dimensional computer-aided design model was developed to clarify how component position in total hip arthroplasty contributes to the primary cause of posterior dislocation in cases of flexion, adduction and internal rotation. To better understand the influences of anteversion angle of the acetabular component, its effects on the primary causes of dislocations and the range of motion were investigated. Three different primary dislocation mechanisms were noted: impingement of the prosthetic femoral neck on the cup liner; impingement of the osseous femur on the osseous pelvis: and spontaneous dislocation caused by soft-tissue traction without impingement. Spontaneous dislocation could be detected by calculating hip forces at any thigh position using the computer-aided design model developed. In computer analysis, a transition from prosthetic impingement rate to osseous impingement rate occurred with increasing anteversion angle of the acetabular component. Spontaneous dislocation was detected at angles &gt; 10 degrees of anteversion of the acetabular component when flexion occurred with extreme adduction and internal rotation. This study demonstrated the possibility of spontaneous dislocation that results not from prosthetic or bony impingement but from muscle traction with increased range of motion. (C) 2011 Elsevier Ltd. All rights reserved.

There are many designs of the femoral stem of a cemented total hip arthroplasty, and mechanical failure of the stem is caused by several factors related to the cement, such as failure of the cement. Optimization of the shape of the stem, especially multiobjective optimization, is required to solve these design problems because a cement fracture is caused by multiple factors. The objective of this study was to determine a stem geometry considering multiple factors at the same time. A three-dimensional finite element model of the proximal femur was developed from a composite femur. A total of four objective functions-two objective functions, the largest maximum principal stress of proximal and distal sections in the cement mantle, for each of the two boundary conditions, walking and stair climbing-were used. The neighborhood cultivation genetic algorithm was introduced to minimize these objective functions. The results showed that the geometry that leads to a decrease in the proximal cement stress and the geometry that leads to a decrease in the distal cement stress were not the same. However, the results of the walking and the stair climbing conditions matched. Five dominant stem designs were considered to be the Pareto solution, and one design was identified as the "better design" for all objective functions. It was shown that multiobjective optimization using a genetic algorithm may be used for optimizing the shape of the femoral stem in order to avoid cement fracture.

The success of total hip arthroplasty (THA) in improving joint function and reducing pain is regarded as one of the great achievements of modern medicine. Today, most femoral stems with cementless fixation are made of either cobalt-chrome-molybdenum (CoCrMb) or titanium-aluminum-vanadium (TiAlV) alloys. In order to obtain adequate initial stability of the cementless femoral stem, the implant must be placed in contact with bone of sufficient strength to support the prosthesis rigidly. This study introduces a unique approach in this research category, making use of shape memory alloys (SMA) for cementless stems to obtain adequate initial stability. Using SMA that exhibits a shape memory effect, better proximal fit and fill with smooth insertion will be accomplished. In this study, numerical evaluation is intended with initial stability of a cementless stem for which SMA is utilized. A result of the numerical analysis reveals that use of SMA is found to be effective enough to obtain rigid initial stability. © 2010, The Japan Society of Mechanical Engineers. All rights reserved.

著者版日本人の脱臼性および亜脱性股関節症患者73関節に対して大腿骨全長5mm間隔でCT撮影を施行し、パーソナルコン ピューター上にて皮質骨の外形、内形の輪郭を抽出した。3次元CADであるPro ENGINEER(Parametric Technology)にて大腿骨の各種計測を行った。症例の中には大腿骨頸部前捻が強く、骨髄腔がかなり狭い例が含まれており、ステムを細くストレート にし、オフセットを確保した製品が必要であることが明らかになった。3次元有限要素法によりデザインの妥当性を検討し、ステムサイズ(1〜7号)を決定し た。この製品はハイブリッド型THA4-U Hip Systemとして、ナカシマメディカルより販売されている。当科および関連病院にて、約550関節の初回THA手術が終了しているが、ほぼテンプレート を用いた術前計画通り手術が行われ、短期成績は良好である。

Most spectacle frames are now made of titanium alloy. Recently, however, frames made of gum metal have become available. Gum metal is a new material having a low Young's modulus, high strength and high elastic deformation. The effectiveness of these spectacle frames, however, has not yet been mechanically evaluated. In this study, by using the recently proposed optical 3D shape measurement method, the deformation behavior of full-rim and rimless spectacle frames, made of gum metal and available on the market, were compared with that of conventional titanium frames. In addition, CAD models of these frames were created and their mechanical characteristics were evaluated in detail by the finite element method. Consequently, the gum metal frames were found more comfortable to wear than titanium ones. However, the rimless type of gum metal frames allowed more load to reach the front than did the titanium frames, causing lens damage due to stress concentration at the screws.

This paper presents experimental data obtained from both in vivo and in vitro compression of the large intestine of goat. In vivo experimental data were obtained from compression tests on the large intestine of an anesthetized goat using force-displacement acquisition equipment. In vitro experimental data were also obtained from tissue excised after the in vivo experiments, and two types of data were then compared. The results demonstrated that the stress values had a strong dependence on the compressive rate in the in vivo experiments, although such effect was not distinct in the in vitro experiments. Additionally, at a lower compression rate, the intestinal tissues were found to be stiffer in the in vitro experiments than in the in vivo ones. This paper is a preliminary report on the mechanical properties of the large intestine based on in vivo and in vitro experimental data. © 2006 IPEM.

As the heart failure is caused by the decrease in the myocardial contraction, the direct mechanical myocardial assistance in response to physiological demand, that is, the synchronous support of the contractile function from outside of the heart, might be effective. The purpose of this study was to develop an artificial myocardium which was capable of supporting the cardiac contraction directly by using the shape memory alloy fibres based on nanotechnology. Some methodologies using novel devices other than the artificial hearts are proposed so far with severe heart disease. However, it was also anticipated that the decrease in cardiac functions owing to the diastolic disability might be caused by using those ‘static’ devices. Then, this study was focused on an artificial myocardium using shape memory alloy fibres with a diameter of 100 – 150 um, and the authors examined its mechanism in a mock circulatory system as well as in animal experiments using goats. Basic characteristics of the material were evaluated prior to the hydrodynamic or hemodynamic examination using a mock ventricular model. The results were as follows: a) The length of the structure was able to be adjusted so that the system could wrap the whole heart effectively. b) In the hydrodynamic study using the mock circulatory system, the myocardial system was able to pump a flow against the afterload of arterial pressure level. c) In the animal experiments, aortic pressure and flow rate were elevated by 7 and 15% respectively by the mechanical assistance of the artificial myocardium, which was driven synchronising with the electrocardiogram, and also, d) The anatomically-identical shape of the artificial myocardium might be more effective for the assistance. In conclusion, it was indicated that this controllable artificial myocardial support system was effective for the mechanical cardiac support for the chronic heart failure.

As the result of developments in computer technology in recent years, the calculation, simulation and analysis of the stress environment for the artificial hip prosthesis and the femur have been made possible. In order to perform an exact calculation, three-dimensional modeling with the hip prosthesis and femur is required. The modeling of a femur is done by reconstructing the femoral outline data from CT images using three-dimensional CAD. The outline extraction work is performed by the experience and subjectivity of the operator, and the reliability of the data and working efficiency is low. In this paper, algorithms that extract the femur outline from CT images automatically are proposed. A Snake-based outline extraction algorithm is used. Although this method is capable of extracting the cortical bone outline of femoral diaphysis with sufficient accuracy, there was high incorrect detection at the trochanter. The shape of the trochanter is complicated, and it is difficult to process using a simple algorithm. Therefore, we proposed a method of visually expressing the possibility that a certain pixel in an image is high or low. This method is capable of detecting portions of images with high differentiations in value (contrast changes rapidly). It can also detect outlines at the diaphysis and trochanter. The problems of this technique are that the pixels judged as possibly being a part of the outline appear in the portion that is not a true outline, and that the pixels judged as possibly being on the outline may not be continuous. When each method was used independently, neither was capable of performing a positive outline extraction. However, an outline sampling sufficiently high certainty was achieved when using the two methods simultaneously.

This paper presents experimental data obtained from the in vivo compression of the large intestine of goat and describes its non-linear and viscoelastic mechanical properties. Data were obtained from compression tests on the large intestine of an anesthetized goat using a stress-strain acquisition equipment. The tissue was first compressed with a constant rate then hold at a maximum strain for 300 seconds. All the results demonstrated highly non-linear stress-strain behavior during the compression phase. The stress versus time curve during the relaxation phase was obtained and the reduced-stress relaxation function was applied. This paper serves as a preliminary report on the mechanical properties of large intestine based on in vivo experimental data.

In this work a manipulator made of a shape memory alloy (SMA) and driven by thermoelectric modules is described. The mechanical output of the manipulator is obtained during the phase transformation of the SMA. To control the mechanical output, the relation between the transformation and the deformation of the SMA has to be determined. In this paper, a phenomenological model is proposed to predict the mechanical behavior of the SMA manipulator. Its validity is confirmed by a comparison of the deformation results between the numerical simulation and experiments.

The authors propose a novel concept for less invasive hemostatic forceps. The proposed hemostatic forceps employ superelastic shape memory alloys that enable one to maintain the clamping pressure within a safe range. In this paper, the basic design of these hemostatic forceps is described. The validity of the concept is demonstrated by experimental results using a prototype.

This article presents some progress in the development for preclinical trials of an artificial anal sphincter using shape memory alloys. The novel device has been proposed and developed by the author's group at Tohoku University. It has two dominant features different from other systems, which are either clinically available or still under development. One is that a solid driving element, a combination of shape memory alloy (SMA) ribbons and silicone elastomer sheets with a layered structure, is adopted for the opening and closing functions of the artificial sphincter. The other is a sandwich mechanism for the closing of bowel to reduce the risk of buckling induced ischemia which has been reported in hydraulically driven artificial sphincters with a radial squeezing mechanism. The device has fewer parts inside the body and therefore be implanted more easily. A new design eliminating the risk of heat burns enables long-term implantation and brings the device closer to practical use. Functionality and safety of the device have been proved in three-month animal experiments.

Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis. -Type A behavior; Brachial-ankle pulse wave velocity; arteriosclerosis (c) 2006 Tohoku University Medical Press.

As the result of developments in computer technology in recent years, the calculation, simulation and analysis of the stress environment for the artificial hip prosthesis and the femur have been made possible. In order to perform an exact calculation, three-dimensional modeling with the hip prosthesis and femur is required. The modeling of a femur is done by reconstructing the femoral outline data from CT images using three-dimensional CAD. The outline extraction work is performed by the experience and subjectivity of the operator, and the reliability of the data and working efficiency is low. In this paper, algorithms that extract the femur outline from CT images automatically are proposed. A Snake-based outline extraction algorithm is used. Although this method is capable of extracting the cortical bone outline of femoral diaphysis with sufficient accuracy, there was high incorrect detection at the trochanter. The shape of the trochanter is complicated, and it is difficult to process using a simple algorithm. Therefore, we proposed a method of visually expressing the possibility that a certain pixel in an image is high or low. This method is capable of detecting portions of images with high differentiations in value (contrast changes rapidly). It can also detect outlines at the diaphysis and trochanter. The problems of this technique are that the pixels judged as possibly being a part of the outline appear in the portion that is not a true outline, and that the pixels judged as possibly being on the outline may not be continuous. When each method was used independently, neither was capable of performing a positive outline extraction. However, an outline sampling sufficiently high certainty was achieved when using the two methods simultaneously.

In artificial internal organs, smaller is better. And an important issue is bio affinity. From these points of view, Regenerative medicine and Nano technology are very useful technology. In Tohoku University, various artificial internal organ research including Artificial esophagus, Artificial Myocardium, and Artificial sphincter based on 21 COE program. Ideal artificial organs may be embodied in future.

An artificial anal sphincter utilizing shape memory alloy (SMA) is one of the implant devices for the patients using artificial anus. The device requires an adequate rise in temperature for its actuation, although overheating should be avoided. A suitable configuration for contact-less power supply to the artificial sphincter and a new method of temperature control were proposed in this work. A small inductor with thermosensitive magnetic ferrite core has been developed for a key device for temperature control as well as power supply. ne Curie temperature of the ferrite was set around the SMA's phase transformation temperature, so that at the temperature the inductor restrains electric power to the heater attached to a SMA plate in order to prevent the overheating. Therefore, it is possible to control the temperature of SMA plate.

The authors have been developing an artificial myocardium using a sophisticated covalent shape memory alloy fibre, which is capable of assisting natural cardiac contraction from the outside of the ventricular wall. We applied engineering method based on robotics control and constructed the artificial myocardial assist system which might be able to regulate derangement and regenerative tensile force on the surface of heart. In this study, a design to surround the total heart has been established in order to refrain from the stress concentration by the mechanical assistance, and the hemodynamic performance of the artificial myocardial assist system were examined in a mock circulatory system as well as on animal experiments using goats. Basic characteristics of the shape memory alloy fibre unit were examined and the displacement control could be achieved under the condition of the different external temperature by feedback using the PID control. And also the increase of the external work of the goats left ventricular pressure-volume relationship were obtained by the assistance using an artificial myocardium with parallel-linked configuration, and therefore it was indicated that the effective ventricular mechanical support could be performed by the device.

The number of stem designs for total hip arthroplasty is increasing, and occasionally design changes have yielded unexpected clinical results. At present, we are not able to clearly identify which parameter of the stem is most important, and the optimum value of many parameters. The goals of this study were to identify which parameter is most important, to understand the effect of design change, and to find the optimum stem shape. For this purpose, we used adaptive p-method together with three-dimensional computer-aided design software program for the design sensitivity analysis (DSA) and shape optimization of the stem. The results suggested that increasing the lateral and medial width of the distal cross-section together with decreasing the medial-lateral width and the medial radius of the distal cross-section from the default value would lead to a decrease in the largest maximum principal stress of the distal cement. The medial width of middle cross-section, however, was not so simple. The result of DSA suggested that decreasing this parameter from the default value decreased the stress in the distal cement, but the optimum shape was obtained by increasing this parameter. The method used in this study will assist our engineers and surgeons in the process of modifying and optimizing the stem design.

Where is a place to be assisted for the patients with congestive heart failure? It is contraction of myocardium. We do not need to exchange the whole hearts. We started the ARTIFICIAL MYOCARDIUM development project. In the first step, pneumatic drive type artificial myocardium was developed. Next, development of an implantable type device was started. The animal experiment which studies the direct ventricle supporting effect by this motor was conducted. Although cardiac assistance of the right ventricle was enough as a result of repeating an animal experiment, the left ventricle supporting effect was inadequate. By such reason, we planned the development of an electrohydraulic driving system with grass fiber belt for fixation. The drive system with which it equipped between ribs controls silicon oil in our plan. Energy is supplied by transcutaneous energy transmission system from the outside of the body. As the results, this device is easily attached to the ventricle and the left ventricle and the right ventricle were able to be assisted as a result of the animal experiment. The cardiac output increased and blood pressure rose in the time series data during artificial myocardium support. Since this device is not a pump, it does not have a valve and does not have the risk of a thrombus, either. Therefore, it is also possible to implant in prevention to a slight heart failure patient. It is expected that it becomes an important artificial organ with a big market.

This article proposes a novel concept of hemostatic forceps for less invasive surgical operation. Hemostatic forceps has more than 400-year's history but remain an instrument with a potential of over-pressure induced lesion. The proposed hemostatic forceps allows a possibility to limit the clamping pressure within a safe range. This is to be realized by employing the constant stress property of superelastic shape memory alloys to limit the pressure applied on biological tissues. It is expected that the development of safe hemostatic forcepses based on this concept would reduce medical accidents.

Severe dysfunction of muscle tissues can be treated by transplantation but the success rate is still not high enough. One possibility instead is to replace the dysfunctional muscle with artificial muscles. This article introduces a unique approach using shape memory alloys (SMAs) to replace the anal sphincter muscle for solving the problem of fecal incontinence. The use of SMAs that exhibit a two-way shape memory effect allows the device to function like a sphincter muscle and facilitates simple design. In this article, we will give a brief introduction to the functional material-SMA-together with its medical applications, and will follow this with a description of the recent progress in research and development of an SMA-based artificial sphincter. The possibility of its commercialization will also be discussed.