A Novel Electromagnetic Targeting System Using Rotating Magnetic-Flux Concentration Method for Navigating Endo-Bronchoscopy

Author(s):  
Chin-Chung Chen ◽  
Ching-Kai Lin ◽  
Yun-Chien Cheng ◽  
Chen-Wei Chang ◽  
Sung-Lin Tsai ◽  
...  

In this paper, we proposed a novel electromagnetic targeting system using rotating magnetic-flux concentration method for navigating endo-bronchoscope. This system consists of a magnetic-flux emitting coil, a magnetic-flux receiving electromagnets-array, a 2D model of bronchial tree, the magnetic-flux concentrator embedded on brush-guiding tube which was connected to the guide sheath. When the concentrator in the 2D bronchial tree passes through the air gap between the emitting coil and the receiving electromagnets-array, the concentrator concentrates the magnetic flux between the coil and the array. The concentrated magnetic flux is subsequently received by the receiving electromagnets-array and thus stable voltage output is produced. Furthermore, when the concentrator is rotated, the concentration of the magnetic flux is periodically changed and thereby the voltage output is periodically changed. By analyzing the voltage changes, the location of the concentrator (as well as guide tube and sheath) is targeted. According to the experimental results, the system successfully targets the location of the guide sheath in the 2D model of bronchial tree.

2020 ◽  
Vol 13 (11) ◽  
pp. 4238-4248 ◽  
Author(s):  
Hyunseok Song ◽  
Deepak Rajaram Patil ◽  
Woon-Ha Yoon ◽  
Kwang-Ho Kim ◽  
Cheol Choi ◽  
...  

A magneto-mechano-electric (MME) generator comprising a magnetoelectric (ME) composite and magnetic flux concentrator (MFC) can effectively harvest the tiny magnetic noise to power the autonomous internet of things (IoT) sensor networks.


Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5105
Author(s):  
Chen ◽  
Lin ◽  
Chang ◽  
Cheng ◽  
Chen ◽  
...  

In this paper, we demonstrate an innovative electromagnetic targeting system utilizing a passive magnetic-flux-concentrator for tracking endobronchoscope used in the diagnosis process of lung cancer tumors/lesions. The system consists of a magnetic-flux emitting coil, a magnetic-flux receiving electromagnets-array, and high permeability silicon-steel sheets rolled as a collar (as the passive magnetic-flux-concentrator) fixed in a guide sheath of an endobronchoscope. The emitting coil is used to produce AC magnetic-flux, which is consequently received by the receiving electromagnets-array. Due to the electromagnetic-induction, a voltage is induced in the receiving electromagnets-array. When the endobronchoscope’s guide sheath (with the silicon-steel collar) travels between the emitting coil and the receiving electromagnets-arrays, the magnetic flux is concentrated by the silicon-steel collar and thereby the induced voltage is changed. Through analyzing the voltage–pattern change, the location of the silicon–steel collar with the guide sheath is targeted. For testing, a bronchial-tree model for training medical doctors and operators is used to test our system. According to experimental results, the system is successfully verified to be able to target the endobronchoscope in the bronchial-tree model. The targeting errors on the x-, y- and z-axes are 9 mm, 10 mm, and 5 mm, respectively.


2018 ◽  
Vol 875 ◽  
pp. 77-83 ◽  
Author(s):  
Yu Bi ◽  
Xiao Ming Zhang ◽  
Wan Jun Wang

In this paper, the axial magnetic field amplification characteristics of the trapezoid-shaped magnetic flux concentrator at micrometer scale are studied. The factors of the dimension parameters including the ratio of the outer and inner width, the aspect ratio, the air gap, as well as the material property including the relative permeability influencing on the magnetic gain are analyzed using the finite element method. It indicates that the concentrator with air gap shows obvious magnetic amplification. The concentrator shows intensive magnetic gain with the increasing ratio of the outer and inner width, aspect ratio and the decreasing air gap. When the dimension parameters of the length, the outer width, the inner width, and the air gap are of 1000um, 200um, 10um, and 5um respectively, the magnetic gain of 65 is obtained. Additionally, the magnetic gain increases with the relative permeability of the concentrator. When the relative permeability reaches a certain value, the magnetic gain tends to saturation. The magnetic flux concentrator has a linear working range of 12.8mT. The study can provide a theoretical reference for the design and application of the trapezoid-shaped magnetic flux concentrator.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 969-975
Author(s):  
Hiroaki Kikuchi ◽  
Yuki Sato

We investigated effects of contact gap on magnetic nondestructive evaluation technique using a magnetic single-yoke probe. Firstly, we evaluated hysteresis curves and impedance related to permeability of the material measured by a single-yoke probe, when an air gap length between the probe and specimens changes. The hysteresis curve gradually inclines to the axis of the magneto-motive force and magneto-motive force at which the magnetic flux is 0 decreases with increasing the gap length. The effective permeability also decreases with increasing the gap thickness. The incremental of gap thickness increases the reluctance inside the magnetic circuit composed of the yoke, specimen and gap, which results in the reduction of flux applying to specimen.


2010 ◽  
Vol 130 (7) ◽  
pp. 698-703 ◽  
Author(s):  
Keisuke Eguchi ◽  
Shingo Zeze ◽  
Takashi Todaka ◽  
Masato Enokizono

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.


2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Hari Prasetijo ◽  
Winasis Winasis ◽  
Priswanto Priswanto ◽  
Dadan Hermawan

This study aims to observe the influence of the changing stator dimension on the air gap magnetic flux density (Bg) in the design of a single-phase radial flux permanent magnet generator (RFPMG). The changes in stator dimension were carried out by using three different wire diameters as stator wire, namely, AWG 14 (d = 1.63 mm), AWG 15 (d = 1.45 mm) and AWG 16 (d = 1.29 mm). The dimension of the width of the stator teeth (Wts) was fixed such that a larger stator wire diameter will require a larger stator outside diameter (Dso). By fixing the dimensions of the rotor, permanent magnet, air gap (lg) and stator inner diameter, the magnitude of the magnetic flux density in the air gap (Bg) can be determined. This flux density was used to calculate the phase back electromotive force (Eph). The terminal phase voltage (V∅) was determined after calculating the stator wire impedance (Z) with a constant current of 3.63 A. The study method was conducted by determining the design parameters, calculating the design variables, designing the generator dimensions using AutoCad and determining the magnetic flux density using FEMM simulation.  The results show that the magnetic flux density in the air gap and the phase back emf Eph slightly decrease with increasing stator dimension because of increasing reluctance. However, the voltage drop is more dominant when the stator coil wire diameter is smaller. Thus, a larger diameter of the stator wire would allow terminal phase voltage (V∅) to become slightly larger. With a stator wire diameter of 1.29, 1.45 and 1.63 mm, the impedance values of the stator wire (Z) were 9.52746, 9.23581 and 9.06421 Ω and the terminal phase voltages (V∅) were 220.73, 221.57 and 222.80 V, respectively. Increasing the power capacity (S) in the RFPMG design by increasing the diameter (d) of the stator wire will cause a significant increase in the percentage of the stator maximum current carrying capacity wire but the decrease in stator wire impedance is not significant. Thus, it will reduce the phase terminal voltage (V∅) from its nominal value.


2013 ◽  
Vol 111 ◽  
pp. 77-81 ◽  
Author(s):  
Xu Sun ◽  
Lijun Jiang ◽  
Philip W.T. Pong

1970 ◽  
Vol 110 (4) ◽  
pp. 25-29 ◽  
Author(s):  
C. Akuner ◽  
E. Huner

In this study, the axial flux permanent magnet motor and the length range of the air gap between rotors was analyzed and the appropriate length obtained. NdFeB permanent magnets were used in this study. Permanent magnets can change the characteristics of the motor's torque. However, the distance between permanent magnets and the air gap will remain constant for each magnet. The impact of different magnet angles for the axial flux permanent magnet motor and other motor parameters was examined. To this aim, the different angles and torque values of the magnetic flux density were calculated using the finite element method of analysis with the help of Maxwell 3D software. Maximum torque was obtained with magnet angles of 21°, 26°, 31.4°, and 34.4°. Additionally, an important parameter for the axial flux permanent magnet motor in terms of the air gap flux was analyzed. Minimum flux change was obtained with a magnet angle of 26°. The magnetic flux of the magnet-to-air-gap is under 0.5 tesla. Given the height of the coil, the magnet-to-air-gap distance most suitable for the axial flux permanent magnet motor was 4 mm. Ill. 11, bibl. 4, tabl. 2 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.280


2012 ◽  
Vol 260-261 ◽  
pp. 554-558 ◽  
Author(s):  
Jeeng Min Ling ◽  
Tajuddin Nur

Inset Permanent Magnet synchronous machine (Inset - PMSM) is a specific kind of permanent magnet synchronous machine. The magnetic flux in air gap of electrical machine is one of the important parameters and it imply to the electric or mechanical energy of machine. Using radial pole structure, the characteristics of magnetic field in air gap of an Inset PMSM with 6 poles and 36 slots are simulated. In this paper, we simulated and observed the influence of axial channel rotor core of Inset-PMSM to the value/quantity of magnetic flux in air gap. Magnetic flux quality is also considered in this simulation. The simulations were compared with the conventional rotor structure. The flux density per pole in the air gap was measured with three different angles, 00, 250 and 400.


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