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Endoscopic submucosa dissection (ESD) procedures, used to remove cancerous tissue from thin-walled organs such as the duodenum, often result in compromising the organ’s functionality, resulting in problematic leakage. While a device has been developed to enable the adherence of a cell sheet to provide additional protection (thickness) to the lining, the device is not suited to laparoscopic application. We have developed and tested a new device and procedure that can be used laparoscopically to adhere cell sheets to organs., Sensors and Materials, 33(3), pp. 973-979; 2021

Internet usage has become an essential part of our daily lives, it has become universal. The aim of this research is to consider existing Internet-based networks with regard to their support for the remote operation of robotic technology, in particular, looking at transmission speed and delay time as it relates to teleoperation. Currently dedicated connections are typically used when a high Quality of Service (QoS) is required for mission critical services or safety-critical systems (SCS), however such connections are very expensive to set up and maintain. Therefore, this study focuses on modifying existing internet networks in a manner to provide a better QoS with little additional cost. Using a number of microcontrollers, computers, and routers, two different protocols were used to control a robotic device remotely. Use of the Point-to-Point Tunnelling Protocol (PPTP) used for implementing a Virtual Private Network (VPN) was found to provide higher average transmission speeds compared to the using a Uniform Resource Locator (URL) which is a regular internet connection.

Food consumption is increasing as the world population increases. While the eating of fish is spreading worldwide, the depletion of fishery resources has become a problem owing to overfishing, and the importance of aquaculture is increasing in order to continue to supply fish as food. In marine aquaculture, fish are grown in aquaculture cages in the sea. Thus, if a harmful algal bloom (HAB) reaches the cages, it will cause serious damage. Countermeasures against HAB are one of the important problems for aquaculture fishermen. In Nagasaki Prefecture in Japan, countermeasures against HAB include patrolling and sampling water by ships. These samples are then submitted to HAB experts for analysis. Following this analysis, notification is provided to aquaculture fishermen. When HAB is detected early, aquaculture fishermen can minimize the damage of HAB by stopping feeding and moving the aquaculture cages. In this study, we developed a system of early detection and notification of HAB to aquaculture fishermen. This is carried out by patrolling and sampling water using drones, detection of HAB by microscope and PC operation, and automatic notification by email and web application. As a result of this developed system, the identification accuracy of harmful plankton is more than 90%, and the time taken to find HABs can be shortened from the 6 h of the conventional approach to 15 min using this newly developed system., Sensors and Materials, 31(12), pp.4155-4171; 2019

Objectives. Thoracic drainage is a common procedure to drain fluid, blood, or air from the pleural cavity. Some attempts to develop approaches to new thoracic drainage systems have been made; however, a simple tube is often currently used. The existing drain presupposes that it is placed correctly and that the tip does not require moving after insertion into the thoracic cavity. However, in some cases, the drain is not correctly placed and reinsertion of an additional drain is required, resulting in significant invasiveness to the patient. Therefore, a more effective drainage system is needed. This study aimed to develop and assess a new thoracic drain via a collaboration between medical and engineering personnel. Methods. We developed the concept of a controllable drain system using magnetic actuation. A dry laboratory trial and accompanying questionnaire assessment were performed by a group of thoracic and general surgeons. Objective mechanical measurements were obtained. Porcine experiments were also carried out. Results. In a dry laboratory trial, use of the controllable drain required significantly less time than that required by replacing the drain. The average satisfaction score of the new drainage system was 4.07 out of 5, indicating that most of the research participants were satisfied with the quality of the drain with a magnetic actuation. During the porcine experiment, the transfer of the tip of the drain was possible inside the thoracic cavity and abdominal cavity. Conclusion. This controllable thoracic drain could reduce the invasiveness for patients requiring thoracic or abdominal cavity drainage.

In this paper, we propose a method to control position of an underwater vehicle using a monocular camera. This method does not require an expensive Inertial Measurement Unit(IMU), but uses template matching to track a target in the water and calculate the amount of movement of the vehicle. Then, it is used to control the vehicle by PID control.

Objectives. In recent years, video-assisted thoracoscopic surgery (VATS) has increasingly become the preferred technique for thoracic surgery. However, the inherent characteristics of the lungs as large, soft, slippery, and delicate creates difficulties for pulmonary surgery. In this article, we outline the development and assessment of a balloon-based organ retractor for VATS via collaboration between medical and engineering personnel. Methods. A dry lab trial and accompanying questionnaire assessment were performed by a group of thoracic surgeons. Objective pressure measurements were obtained, and animal experiment on pigs was performed. Results. In the dry lab trial, use of the developed organ retractor required significantly less time and resulted in fewer difficulties than using a Cherry Dissector. The measured pressure per mm2 of the developed retractor was clearly lower than that for the Cherry Dissector. The questionnaire completed by the surgeons following the dry lab and animal experiments showed that most of the surgeons (7 surgeons out of 9) were satisfied with the quality of the balloon-based retractor based on a score of 3.13 ± 0.28 (mean ± standard deviation) out of 4.0. During the animal experiment, the balloon-based retractor provided stable and clear viewing with minimal need for adjustment. Conclusion. This balloon-based retractor could contribute to increased safety and less-invasive VATS.

While laparoscopic surgery has become increasingly widely used, many laparoscopic procedures are time-consuming and difficult to accomplish compared to open surgery. One such procedure is the ligation of endless organs. In this paper, the development and prototyping of a laparoscopic instrument that could significantly increase the efficiency of laparoscopic ligation is outlined. The mechanism is based on a snake-like flexible structure which is actuated by control wires. A simple simulation was carried out by both experienced surgical staff as well as non-surgical persons to confirm the effectiveness of the proposed mechanism., Computer Assisted Surgery, 22(S1), pp.36-44; 2017

On-machine measurement is used in ultra-processing machining, but it is seldom used in precision machining. For on-machine measurement, it is necessary that the sensor not be easily affected by the moving error or environment vibration in the field of precision machining. A triangulation method sensor with the optical skid method made using a new design concept is proposed to remove the moving error and vibration. The optical skid method used two laser spots with different sizes: the small spot diameter is the stylus and the large spot diameter is the skid [1]. The difference between these two signals reflects the surface shape. The developed sensor comprises an optical source and two optical receiving systems. Each optical receiving system has an imaging lens and a detector. Instead of two laser spots of different sizes, two detectors with different sizes of receiving area serve as the optical skid. Results confirmed the possibility of reducing the influence of the vibration using the developed sensor. In on-machine measurements, measurement of the surface profile with long wavelength is often necessary. If the spot diameter of the skid is not much larger than the surface profile wavelength, then the smoothing effect of the skid is reduced. Therefore, the amplitude of the measured profile by the skid sensor is smaller than actual amplitude of the workpiece. This paper presents a method of reconstructing the surface profile from the measurement results and the obtained effects of the reconstruction method from simulations and experiments.

The author developed key technologies for the next long cruising autonomous underwater vehicle. Layout is designed by CAD, the prototype vehicle is manufactured and tested in the tanks. As results, longer cruising than the conventional type underwater vehicle like Urashima is possible by low resistance shape and with hydrofoils.

The generation of clean renewable energy is becoming increasingly critical, as pollution and global warming threaten the environment in which we live. While there are many different kinds of natural energy that can be harnessed, marine tidal energy offers reliability and predictability. However, harnessing energy from tidal flows is inherently difficult, due to the harsh environment. Current mechanisms used to harness tidal flows center around propeller-based solutions but are particularly prone to failure due to marine fouling from such as encrustations and seaweed entanglement and the corrosion that naturally occurs in sea water. In order to efficiently harness tidal flow energy in a cost-efficient manner, development of a mechanism that is inherently resistant to these harsh conditions is required. One such mechanism is a simple oscillatory-type mechanism based on robotic fish tail fin technology. This uses the physical phenomenon of vortex-induced oscillation, in which water currents flowing around an object induce transverse motion. We consider two specific types of oscillators, firstly a wing-type oscillator, in which the optimal elastic modulus is being sort. Secondly, the optimal selection of shape from 6 basic shapes for a reciprocating oscillating head-type oscillator. A numerical analysis tool for fluid structure-coupled problems?ANSYS?was used to select the optimum softness of material for the first type of oscillator and the best shape for the second type of oscillator, based on the exhibition of high lift coefficients. For a wing-type oscillator, an optimum elastic modulus for an air-foil was found. For a self-induced vibration-type mechanism, based on analysis of vorticity and velocity distribution, a square-shaped head exhibited a lift coefficient of more than two times that of a cylindrically shaped head. Analysis of the flow field clearly showed that the discontinuous flow caused by a square-headed oscillator results in higher lift coefficients due to intense vortex shedding, and that stable operation can be achieved by selecting the optimum length to width ratio., Applied Sciences, 7(10), 1070; 2017

Synthetic fibre ropes are in widespread use in maritime applications ranging from lifting to temporary and permanent mooring systems for vessels, offshore equipment and platforms. The selection of synthetic ropes over conventional steel components is motivated by several key advantages including selectable axial stiffness, energy absorption (and hence load mitigation), fatigue resistance and low unit cost. The long-term use of ropes as safety critical components in potentially high dynamic loading environments necessitates that new designs are verified using stringent qualification procedures. The International Organization for Standardization (ISO) is one certification body that has produced several guidelines for the testing of synthetic ropes encompassing quasi-static and dynamic loading as well as fatigue cycling. This paper presents the results of tension-tension tests carried out to ISO 2307:2010, ISO 18692:2007(E) and ISO/TS 19336:2015(E) on three different 12-strand rope constructions manufactured by Ashimori Industry Co. Ltd from polyester and Vectran® fibres. The purpose of the tests was to characterise the performance of a novel 12-strand construction and compare this to a conventional 12-strand construction. Utilising the Dynamic Marine Component test facility (DMaC) at the University of Exeter several key performance metrics were determined including; elongation, minimum break load (MBL) and quasi-static and dynamic stiffness. During the ISO 2307:2010(E) test programme the samples were tested dry and during the ISO 18692:2007(E) and ISO/TS 19336:2015(E) test programmes the samples were fully submerged in tap water after being soaked for at least 24 hours. Two methods were used to quantify sample extension: i) an optical tracking system and ii) a draw-wire potentiometer. Axial compression fatigue and cyclic loading endurance tests were also carried out on two Vectran® samples. Further load-to-failure tests and sample analysis were also carried out by Ashimori Industry Co. Ltd. It was found that the MBL of the samples exceeded the values specified by the manufacturer (by 7.7–29.5% for the polyester samples) with failure occurring at the splices in all cases and minor abrasion noted in several locations. The measured MBL of the novel polyester Straight Strand Rope (SSR) construction was up to 16% higher than the conventional construction with increases of quasi-static and dynamic stiffness of up to 6.8%. Differences between the viscoelastic and viscoplastic behaviour of the samples were also noted. The data obtained during these tests will provide insight into the behaviour of these materials and different rope constructions which will be of use to rope manufacturers, mooring system designers in addition to offshore equipment and vessel operators.

The authors have developed wrist rehabilitation robot for hemiplegic patients. The robot is much effective for repetitive rehabilitation, and useful for patients. Mirror effect control system is developed based on the experience that a patient can easily move a limb while moving a limb on the other side. The effectiveness is successfully confirmed by the practical test in the hospital., 3rd International Conference on Advanced Materials Design and Mechanics, ICAMDM 2014; ; 23 May 2014 through 24 May 2014, Applied Mechanics and Materials, 597, pp.397-400; 2014

The authors have developed a shark ray robotic fish based on biomimetic approaches. The paper describes the newly developed robotic fish technology and its application to mechatronics in the space. It is found that robotic fish technology creates not only new underwater robotics, but also the next generation space mechatronics for geological survey of lunar/planets and dust cleaning in the space station., 2013 the 3rd International Conference on Mechatronics and Applied Mechanics (ICMAM2013), Dec.27-28, 2013 Paris, France, Applied Mechanics and Materials, 527, pp.224-229; 2014

The authors developed low cost unmanned helicopter, real time video data transmitting system and a new type flying robots. The effectiveness is confirmed by real field experiment tests. Hazard map for disaster countermeasures is made on the basis of data obtained by the aviation vehicle system. The hazard map is delivered directly to a smart phone and a tablet PC. Therefore residents can keep track of disaster information quickly and accurately., 2013 International Conference on Materials, Transportation and Environmental Engineering, CMTEE 2013; Taichung; Taiwan; 21 August 2013 through 23 August 2013, Advanced Materials Research, 779-780, pp,908-915; 2013

This paper describes development of autonomous robot to clean dust in the International Space Station. Clean robot having an autonomous flight control and navigation in Japanese Experiment Module named "KIBO". And, it has function to collect dust which can't be recovered by ISS air conditioning. In this study, the authors chose to fish shapes for cleaning robot. Elastic oscillation fin was realized to have high controllability and soft behavior of creatures. Robotic fish takes evasive action by detecting the astronauts, walls, and obstacles. Then, cleaning work continues safe in cabin. The purpose of robotic fish is to reduce the cleaning workload of astronauts. And, the basic technology contributes to establish autonomous flight control and navigation in zero gravity., 9th IFAC Conference on Control Applications in Marine Systems, CAMS 2013; Osaka; Japan; 17 September 2013 through 20 September 2013, IFAC Proceedings Volumes, 9(1), pp.386-391; 2013

The author has developed many kinds of robotic fishes based on elastic oscillating fin propulsion system from 1989. The presentation describes past, present, and future robotic fish technologies, and applications of robotic fish technologies to various fields. Firstly, the history of the developed life-like robotic fish, such as sea bream in 1995, coelacanth in 1997, carp in 2000, shark ray in 2004 etc. is mentioned. The developed robotic fishes are basically propelled by vertical tail fin and operated by servo motors. Secondly, the life-like robotic dolphin was newly developed in 2013. The author developed tethered whale robot with horizontal tail fin propelled by hydraulic actuator in 1990s, however, the robotic dolphin is untethered and higher length, that is more than 1m, and has characteristic of fast cruising and higher maneuverability with horizontal tail fin propelled by servo motors. Thirdly, new application fields of robotic fish technologies, such as medical forceps and extractors, space robots which went to International Space Station and swam in the space, and current power plant using oscillating fin propulsion system for new offshore sustainable energy are described. Finally, robotic fish technologies for the next generation underwater vehicle are summarized.

Background Fine-needle aspiration cytology (FNAC) is a challenging and risky procedure for inexperienced clinicians to perform because of the proximity of the thyroid to the jugular veins, carotid arteries, and trachea. A phantom model for transfixion practice would help train clinicians in FNAC. Objective To fabricate a tailored phantom with consideration for authenticity of size, touch, feel, and ultrasonographic (US) characteristics. Methods A three-dimensional (3D) digital model of the human neck was reconstructed from computed tomography data of a subject. This model was used to create 3D-printed templates for various organs that require US visualization. The templates were injected with polymers that provided similar degrees of ultrasound permeability as the corresponding organs. For fabrication of each organ, the respective molds of organs, blood vessels, thyroid gland, and tumor were injected with the material. The fabricated components were then removed from the templates and colored. Individual components were then positioned in the neck mold, and agar gel was poured in. The complete phantom was then removed from the mold. Thereafter, 45 medical doctors and students performed ultrasound-guided FNAC using the phantom, following which they were queried regarding the value of the phantom. Results The structure, US characteristics, and elasticity of the phantom were similar to those of the human subject. In the survey, all 45 participants replied that they found the phantom useful for FNAC training, and 30 medical students professed increased interest in thyroid diseases after using the phantom. Conclusions We successfully fabricated a tailored thyroid gland phantom for transfixion practice. As most of the phantom parts are injected in molds fabricated using a 3D printer, they can be easily reproduced once the molds are fabricated. This phantom is expected to serve as an effective and fully tailored training model for practicing thyroid gland transfixion.

The dynamics and control design necessary in the development of robotics and mechatronics are reviewed in this chapter.

Development of ocean energy power generation has long been considered potentially the next generation of renewable energy resources. The author has begun research on the construction of cluster-based offshore ocean energy generation technology, as shown in Figure 9.1. Specifically, this includes the development of a hybrid of wind power, wave power, and tidal power generation, and the development of marine equipment using resilient vibration blades (this type of power generation would be ideally suited for applications such as local fisheries), and the development and construction of power plant maintenance systems. All efforts are being made to promote this concept, and the author and his colleagues are eager to proceed with a prototype system offshore near Nagasaki, Japan. Finally, the author expects that the above technological and human resource development will provide a base or prototype on which an ocean energy industry could potentially be built. Also the author is developing the IoT systems of production and maintenance for the ocean energy industry.

The past, present, and future AUV technologies developed by the author, who belonged to the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) as the leader of the autonomous underwater vehicle group, are described in this chapter. The first to be presented is the deep and long-distance cruising AUV Urashima, powered by a fuel cell, with the following specifications: 10-m length; 2.5-m width; 2.4-m height; 10-tons weight; 300-km cruising distance; and 3500-m depth diving at 3-kt speed autonomously in the ocean. It is used for sea bottom surveys in earthquake areas and for research of global warming phenomena. The second AUV technology described is the next-generation AUV designed by the author for higher manoeuvrability and longer distance cruising than Urashima. Third, this chapter details biomanoeuvring AUVs, which are fish-like swimming robots used for various purposes in scientific research. Finally, a marine system network based on AUVs is described.

The practical wrist rehabilitation robot has been developed and is used in hospitals. The robots are introduced and applied to several hospitals, and the author and his colleagues obtain clinical data to complete the research. In addition, the author and his colleagues improve more functions according to the requirements from medical doctors, therapists, and patients.

The author and his colleagues have developed the robotic fish. The robotic fish technology can create new underwater robotics which can perform life-like swimming. It is found that the technologies of the robotic fish have much potential for creating new space mechatronics through these applications. The author and his colleagues still continue to conduct further experiments to produce these space products.

Classification of robotics and mechatronics, and their needs in society are outlined in this chapter. Robotics and mechatronics penetrate into every part of society. The definition of robotics is as follows: `Robotics is a system of intelligent machinery which consists of sensors, actuators, and a controller.' The definition of mechatronics is `mechanics including an electrical circuit'.

Successful methods of designing basic systems for robotics and mechatronics are described in this chapter. Robotics and mechatronics are a `system'. The definition of system is a `network', which consists of `multiple elements, and has a net performance that exceeds that of each element'. Robotics is a system which consists of sensors, actuators, and a controller, according to the definition of the Japanese Ministry of Economics. Engineers in Japanese industries in the twentieth century referred to mechatronics as a system which consists of mechanics and electronics.

The experiential methods and basic ideas to create practical robotics and mechatronics are presented in this chapter. Robotics and mechatronics are based on several technologies. The most important technologies are mechanics, electronics, electrical engineering, and information technology. A prominent person sometimes creates and develops robotics and mechatronics alone; however, it is rare for a single person to produce them to a marketable level. Usually, a team is organized by engineers from mechanics, electronics, software, manufacturing, and business persons who direct the product development to the market. The author has experienced, that the optimal number of people to create new robotics and mechatronics is five.

In this paper a description is given about the implementation of the Dynamic positioning system in the Seabex (special model ship) software of ship. The effectiveness of DPS is confirmed by numerical simulation and tank test using a model ship. This research is an effective approach to design an offshore platform DPS at one-tenth of cost of conventional method.

In the surgical operation, the research and development of the surgical robot that has both safety and effectiveness is needed in consideration of the physical mental strain decrease of the surgeon and the patient. Through the observation of the motion of fish, it has been found that fish swim efficiently using flexibility of pliable fins, giving the actuator the name of flexible oscillating fin propulsion system. The author proposed the application to the realm of healing the elastic vibration wing promotion system. The flexible forceps robot for the surgical operation of a vibrating flexible fin promotion system application was developed.

This paper describes dynamic positioning system developed for 20 years through research and development by Japan Oil, Gas and Metals National Corporation. It summaries a basic concept of design, simulator, tank test, and real applications. Also, the next generation system of Japan and its basic research is mentioned in the paper.

This paper describes the research and development of a robotic fish. Recently, the development of high performance robotic systems have multiplied across several fields. The development of a robotic system is based on the fusion of many technologies; such as mechanical engineering, electric/electronics engineering, telecommunication engineering, biology, physics, chemistry and so on. For the integration of several technologies we have to proceed from various points of view. The author has developed many such robotic systems, especially in the underwater field. This paper shows the current situation of research and development into robotic fish. This new field is attracting a lot of attention worldwide as we look to the next generation in robotics.

症例は70歳，男性．3日前より持続する右下腹部痛を主訴として外来受診した．血液検査データ上，炎症所見は高値を示し腹部造影CTにて軽度腫大した虫垂を認め，その周囲に隔壁を伴う液貯留がみられた．急性虫垂炎・虫垂周囲膿瘍と診断し，同日緊急手術を施行した．腹腔鏡で観察したところ，虫垂に表面平滑な腫瘤形成を認めた．周囲と癒着しており剥離する際に壁が破裂，白色膿汁が大量に流出した．腹腔鏡下では継続困難と判断し開腹，癒着剥離が困難であり回盲部切除術を施行した．摘出標本では直径約6cmの嚢胞の中央に虫垂様の構造物を認めた．病理組織学的検査では虫垂の嚢胞状拡張を認め，内腔には核腫大を示す上皮の乳頭状増殖を認めたが明らかな悪性所見は認めず膿瘍形成を伴う虫垂粘液嚢胞腺腫と診断された．術後2日目に上腸間膜静脈血栓症を発症するも保存的に改善し第35病日に退院となった．

The Independent Administrative Corporation Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been developing light-and-small autonomous underwater vehicles (AUV), named “Marine Robot Experimental 1” (“MR-X1”). In this paper, the motion control problem of “MR-X1” is considered. Since the dynamics of “MR-X1” depends upon its own speed, the problem in question becomes a non-linear control problem. A new controller design method using linear matrix inequalities (LMIs) is proposed in order to adapt the problem in question. The algorithm, which gives a solution of a linear matrix inequality (LMI), can adapt to solve numerous LMIs simultaneously. LMIs can be obtained by substituting several speeds into the dynamics of “MR-X1”. The proposed controller, which can be derived from the solution of LMIs, becomes a stabilizing controller for all substituted speeds.

In the area of manufacturing surgical instruments, the ability to rapidly design, prototype and test surgical instruments is critical. This paper provides a simple case study of the rapid development of two bio-mechanism based surgical instruments which are ergonomic, aesthetic and were successfully designed, prototyped and conceptually tested in a very short period of time.

Various types of autonomous underwater vehicles (AUVs) have been developed and are used for conventional surveys due to their small size. Large AUVs are also being developed that are equipped with high technology computers, high-precision navigation systems, and efficient power sources. One ocean-going AUV powered by a polymer electrode membrane fuel cell system was completed by The Japan Agency for Marine-Earth Science and Technology. Its fuel cell system generates 4kW of electric power for the control electronics and propulsion system. Hydrogen gas is stored under low pressure in the metal hydride. Heat generated by the fuel cell is used to discharge hydrogen gas into the metal hydride. This article proposes one method in which to equip the proton exchange membrane fuel cell with storage devices for fuel and oxidizer, and a heat transfer device using the new generation AUV as its power source. Test results of the fuel cell, storage system and the 317 km Suruga Basin sea test are presented in this article.

The Japan Agency for Marine-Earth Science and Technology acquired an autonomous underwater vehicle, the URASHIMA, in 2000. It has capacity to cruise for 300 km, and to dive up to 3,500 m depth, and it can approach waypoints correctly using inertial or acoustic navigation during autonomous cruising. Autonomous underwater vehicles are expected to explore environmental problems by measuring various oceanic data. Through sea trials, we have been developing key technologies for the vehicle, such as navigation and power sources. This paper describes the vehicle system and sea trial results.

Purpose To utilize a microwave coagulator for MR-guided interstitial thermal therapy of liver tumors as a clinically feasible heating device. Materials and Methods MR-guided microwave thermocoagulation therapy was carried out 34 times in 30 patients with liver tumors (eight hepatocellular carcinoma, 22 metastatic tumors) using a 0.5 T open configuration MR system. Results Percutaneous puncture could be accomplished both accurately and safely while monitoring real-time magnetic resonance imaging (MRI). Using a notch filter, MR images could be observed without electromagnetic interference even during microwave ablation. Temperature monitoring during ablation was possible using the proton resonance frequency method. All procedures could be successfully carried out without any complications, and the therapeutic effects were deemed satisfactory. Conclusion MR-guided microwave thermocoagulation therapy could be one promising procedure of minimally invasive treatment for liver tumors. J. Magn. Reson. Imaging 2002;16:576–583. © 2002 Wiley-Liss, Inc.

Effective organ retraction is essential to ensure safe and efficient surgery, in the case of laparoscopic surgery, organ retraction is particularly difficult to achieve. Currently such as cherry dissectors are used for retraction, however the small size results in excessive stress on the organ being retracted. Therefore, we are developing a balloon-based retractor that provides similar functionality as the cherry dissector, particularly being able to pass through a small port, yet being expandable to provide a much greater contact area as well as improved traction, thus providing increased operating efficiency and improved safety in organ retraction. In this paper, the relative merits and demerits of a number of currently available retractors are compared. Parameters under consideration include shape, size, effective traction (coefficient of friction), type of actuation and ease of use. While parameters such as pressure distribution and effective traction have been objectively measured, other attributes unique to the individual mechanisms are discussed, and finally feedback is provided from surgeons regarding the respective retractor’s ease of use and perceived efficacy.

Background: The standard procedure for sympathectomy is open surgery. The oblique retroperitoneal approach is popular because it provides good visibility, albeit at the expense of requiring a long skin incision. Chemical sympathectomy has been introduced as a less invasive means of achieving sympatholysis; however, this method is also associated with a significant incidence of incomplete block and transient denervation. Laparoscopic surgery is a new approach that simplifies various surgical procedures. The aim of our report was to evaluate the benefits of endoscopic retroperitoneal surgery for lumbar sympathectomies. Methods: Between March 1997 and April 2000, seven patients underwent laparoscopic lumbar sympathectomy in our department (all men, with an average age or 45.1 years). The predominant presenting symptoms were unilateral pain at rest and lower-extremity coldness. Symphaectomy was performed using a retroperitoneal approach on six patients and an anterior transperitoneal approach on one patient. After laparoscopic lumbar sympathectomy, skin thermometry was carried out on all patients. Results: The postoperative skin temperature of the affected leg rose to 36.6 ± 0.5°C, as compared to 33.8 ± 0.8°C preoperatively. After laparoscopic lumbar sympathectomy, none of the patients complained of neuralgia. All patients achieved sustained symptomatic relief, and no major postoperative complications were noted. Conclusions: Lumbar sympathectomy can be performed laparoscopically. Currently, our standard technique is the retroperitoneal approach. More clinical experience and long-term follow-up will ultimately determine if this will become the procedure of choice. However, we believe that a learning period is necessary for this technique to be fully mastered.

System identification of coupled ship dynamics is problematic with standard least squares methods due to the non-linear, multivariable nature of the system. Neural Networks have therefore been applied to this problem, as they are particularly suitable for approximating non-linear, multivariable functions. In this paper, results of identification with Neural Networks are given for a ship motion simulation based on a standard mathematical model, and for real data collected from a 1/50th scale model of the system. The method is seen to be successful at various operating points, and ideas for extension of the work are discussed.

The purpose of this paper is to describe the feasibility research of marine vehicles with oscillating fin propulsion control system. The oscillating fin propulsion system was designed and constructed to be combined with a ship model. Tank tests using the ship model have confirmed the system's feasibility. As a result, several advantages of the oscillating fin system have been found out. A neural network was successfully applied for an identification of the ship model dynamics with the oscillating fin, and its effectiveness was confirmed. Robotic fish, intended as an amusement attraction for aquariums, using the oscillating fin propulsion system have been developed. Its capability of untethered 3-dimensional movement was confirmed.

Since few previous studies have examined the effects of urocortin on physiological fed and fasted gastrointestinal motility, we administered urocortin intracerebroventricularly (icv) or intravenously (iv) in freely moving conscious rats and examined the changes in antral and duodenal motility. Icv and iv injection of urocortin disrupted fasted motor patterns of gastroduodenal motility, which were replaced by fed-like motor patterns. When urocortin was given icv and iv in the fed state, the motor activity remained like the fed patterns but % motor index (%MI) was decreased in the antrum and increased in the duodenum. Increase in the %MI in the duodenum induced by urocortin was shown as a nonpropagated event, since the transit of nonnutrient contents in the duodenum was decreased by icv and iv injection of urocortin. Changes in the gastroduodenal motility induced by icv injection of urocortin were abolished in animals with truncal vagotomy but not altered in animals with mechanical sympathectomy, suggesting that the vagal pathway may mediate the central action of urocortin. Neither urocortin antiserum nor α-helical CRF-(9–41) affected fed and fasted gastroduodenal motility, suggesting that endogenous urocortin is not involved in regulation of basal gastroduodenal motility.

We have devised a method of determining the optimal value of both the refractive index n and the diameter D of a transparent cylinder by the scattering intensity pattern over a wide range of scattering angle. We have shown that the method is stable to small variations of data for the sample with D#x2272;10#x03BB; (wavelength) and could specifically determine the parameters of a spider#x0027;s thread as n = 1.520 (#x2212;0.033, #x002B;0.033), D=0.564 (#x2212;0.009, #x002B;0.011)#x03BC;m for #x03BB; = 632.8 nm.