Development of active stent moving by ultrasonic vibration

An active stent driving in a blood vessel has been developed by this study. A general stent is inserted in the stenosis part of a blood vessel and is the medical device used for expansion of a blood vessel. However, there is a problem of restenosis that a plaque accumulates around the stent. So, the active stent is used for removal of the plaque. The purpose of this study is drive of the active stent. And a design and a resonance experiment of the active stent were carried out. The active stent consists of two cylindrical receivers and one coil shaped stator. A drive source of the active stent is vibration of the stator. When the ultrasonic is irradiated to the receiver, vibration of the stator occurs. First, the receiver which resonates was designed by numerical analysis. The receivers different in the size based on the analysis result were made. And the size which resonates certainly by the resonance experiment was specified. Next, the active stent was designed. The active stents were made and the size which resonates by the resonance experiment was specified

Micro ultrasonic motor for miniature robot arm

The purpose of this study is development of micro ultrasonic motor for miniature robot arm. It will be assembled to a miniature robot applied to a mesh robot to represent the shape and stiffness of the surface of objects. In the first stage, the authors have developed a micro motor by ultrasonic technology. It has two components: a stator (a cube of 3 mm size) and a rotor (diameter of 1 mm). The authors have designed a new stator and a rotor to increase output torque. The first trial motor shows successfully the potential of the final goal of 5 μNm and 3 rpm with a reduction gear system

Development of intravascular stent robot with cross type receiver

This study proposes a stent motor as a medical device. A stent is a medical instrument inserted in a constricted part of a blood vessel to expand the blood vessel. However, the problem is that plaque accumulates around the installed stent and causes the blood vessel to narrow again. A stent motor is used to remove plaque. A stent motor consists of a receiver part to receive ultrasonic vibration and a stator part to drive the motor in the blood vessel. The purpose of this study was to develop a stent motor and determine its optimum design. It was possible to drive a stent motor by subjecting a disk-shaped receiver to strong ultrasonic vibrations. Experiments were performed on the stent motor with several types of receivers by changing their size and shape, and the efficiency was evaluated. Correlation between the design of the stent motor, such as the number of turns in the stator and the shape of the receiver, and the rotational speed was clarified

A study for the influence of human behavior on a safety marking of electrical machines

Manufacturers aim to design electric machines so that users will not get injured if they misuse them. However, manufacturers are not able to consider all types of misuse that may occur. Therefore, an instruction marking that instructs users regarding actions that prevent misuse of the machine in question must be effective, in particular because it is easy to add an instruction marking to a machine. In this study, we have tried to ascertain what types of instruction markings are effective in terms of preventing users from misusing a machine. For a marking to be effective, it may be important that users can easily notice the marking as then they are more likely to heed the related warning. We have carried out experiments on human behavior focusing on the differences in the position of a marking, whether or not a marking includes an illustration, and whether or not a marking has a flashing light in close proximity

Micro spherical ultrasonic motor using single spiral wire stators

The authors have developed Multi degree-of-freedom micro spherical ultrasonic motor using multiple spiral wire stators in previous research. In this research, the authors have developed the new spherical ultrasonic motor using single spiral wire stators. At the beginning, single spiral type wire stator was made. Next, rotational direction was controlled by duty ratio of traveling wave and standing wave. Then the drive properties of rotational speed and starting torque were clarified in this research. In the future, fixing method of wire stators without damping the vibration is needed to be planed. These results contribute to development of blood vessel endoscope which can move camera in any direction

Evaluation of spherical ultrasonic motor for space in high temperature condition

Development of spherical ultrasonic motor (SUSM) for space is an aim of this investigation. SUSM is a motor of multi-DOF. It's necessary to clear the various conditions to use a motor at space. In this paper, to confirm the durability to the radiant heat from the sun, drive experiments of SUSM was conducted in high temperature condition. As a result, our SUSM maintained the drive performance in high temperature condition. Materials of piezoelectric elements and of adhesives used in SUSM for space were important elements to maintain its drive performance in space. Selection results of the piezoelectric element and the adhesive were also reported in detail

Multi degree-of-freedom micro spherical ultrasonic motor using wire stators

The authors have been developing a micro spherical ultrasonic motor for a blood vessel endoscope to observe a blood vessel and make a diagnosis. It has two degree of freedom in one joint. The endoscope with the motor enables a doctor to control a camera angle to the affected area on the wall of the blood vessel. Comparing to the conventional endoscopes operated by wire-drive with an optical fiber and wide-angle lens, it has the advantages of rotating the camera with a right angle to the wall and obtain a precise image. In this research, we have developed the prototype motor and showed the characteristics of it

Position error estimation of the underwater coordinate measurement machine using artificial neural network

Position error of the underwater coordinate measurement machine (UWCMM) is estimated using an artificial neural network (ANN). The UWCMM has a multi joint serial link and the position of an underwater robot attached to the tip is obtained from kinematics of the link. However, the inaccuracy of the kinematics model creates a position error. In order to improve measurement accuracy, an ANN model which estimate position error of the kinematics of the UWCMM using joint angles data is constructed. The ANN model was trained by 462 data and verified by 42 data. The error estimation result of the trained ANN reduces maximally 66.5 % of the average of the position error of the verification data

Finite element analysis of spherical ultrasonic motor using wire stator with support structure on waveguide

The authors are developing multi degree of freedom micro spherical ultrasonic motor using wire stator for vascular endoscope. Spherical ultrasonic motor with 20 times model is used to confirm the driving characteristics as experimental equipment. Wire stator is designed by assuming the introduction to a vascular endoscope and transient response analysis is performed by the finite element method compared with 20 times model. In this study, the authors improve new support structure on waveguide and investigate new influence of the attenuation of the traveling wave transmitted on the wire stator by analyzing and changing the condition of the model. In the future, the authors will measure the amplitude of the wire stator by experiment and verify the accuracy of the simulation

A study for the influence of human behavior on a safety marking of electrical machines

Manufacturers aim to design electric machines so that users will not get injured if they misuse them. However, manufacturers are not able to consider all types of misuse that may occur. Therefore, an instruction marking that instructs users regarding actions that prevent misuse of the machine in question must be effective, in particular because it is easy to add an instruction marking to a machine. In this study, we have tried to ascertain what types of instruction markings are effective in terms of preventing users from misusing a machine. For a marking to be effective, it may be important that users can easily notice the marking as then they are more likely to heed the related warning. We have carried out experiments on human behavior focusing on the differences in the position of a marking, whether or not a marking includes an illustration, and whether or not a marking has a flashing light in close proximity