WorldWideScience

Sample records for non-contact linear motors

  1. Flux modeling and analysis of a linear induction motor for steel mill non-contacting conveyance system application

    International Nuclear Information System (INIS)

    Liu, C.-T.; Lin, S.-Y.; Yang, Y.-Y.

    2005-01-01

    A detailed mathematical approach for analyzing static/dynamic characteristics of a linear induction motor for steel mill non-contacting conveyance system application will be provided. The dependent reluctances among the motor secondary steel plate and primary poles have been systematically formulated; hence, the operational performance of the system can be derived conveniently. Results showed that not only the motor structure is suitable for the design objective, but also the proposed magnetic equivalent circuit can provide appropriate and convenient modeling for relative analytical investigations

  2. Handbook on linear motor application

    International Nuclear Information System (INIS)

    1988-10-01

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  3. Linear motor coil assembly and linear motor

    NARCIS (Netherlands)

    2009-01-01

    An ironless linear motor (5) comprising a magnet track (53) and a coil assembly (50) operating in cooperation with said magnet track (53) and having a plurality of concentrated multi-turn coils (31 a-f, 41 a-d, 51 a-k), wherein the end windings (31E) of the coils (31 a-f, 41 a-e) are substantially

  4. Linear induction motor

    International Nuclear Information System (INIS)

    Barkman, W.E.; Adams, W.Q.; Berrier, B.R.

    1978-01-01

    A linear induction motor has been operated on a test bed with a feedback pulse resolution of 5 nm (0.2 μin). Slewing tests with this slide drive have shown positioning errors less than or equal to 33 nm (1.3 μin) at feedrates between 0 and 25.4 mm/min (0-1 ipm). A 0.86-m (34-in)-stroke linear motor is being investigated, using the SPACO machine as a test bed. Initial results were encouraging, and work is continuing to optimize the servosystem compensation

  5. Electrodynamic linear motor

    Energy Technology Data Exchange (ETDEWEB)

    Munehiro, H

    1980-05-29

    When driving the carriage of a printer through a rotating motor, there are problems regarding the limited accuracy of the carriage position due to rotation or contraction and ageing of the cable. In order to solve the problem, a direct drive system was proposed, in which the printer carriage is driven by a linear motor. If one wants to keep the motor circuit of such a motor compact, then the magnetic flux density in the air gap must be reduced or the motor travel must be reduced. It is the purpose of this invention to create an electrodynamic linear motor, which on the one hand is compact and light and on the other hand has a relatively high constant force over a large travel. The invention is characterised by the fact that magnetic fields of alternating polarity are generated at equal intervals in the magnetic field, and that the coil arrangement has 2 adjacent coils, whose size corresponds to half the length of each magnetic pole. A logic circuit is provided to select one of the two coils and to determine the direction of the current depending on the signals of a magnetic field sensor on the coil arrangement.

  6. Reciprocating linear motor

    Science.gov (United States)

    Goldowsky, Michael P. (Inventor)

    1987-01-01

    A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

  7. Reciprocating Linear Electric Motor

    Science.gov (United States)

    Goldowsky, M. P.

    1984-01-01

    Features include structural simplicity and good force/displacement characteristics. Reciprocating motor has simple, rugged construction, relatively low reciprocating weight, improved power delivery, and improved force control. Wear reduced by use of magnetic bearings. Intended to provide drivers for long-lived Stirling-cycle cryogenic refrigerators, concept has less exotic applications, such as fuel pumps.

  8. Linear Motor With Air Slide

    Science.gov (United States)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  9. Segmented rail linear induction motor

    Science.gov (United States)

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  10. Linear Synchronous Motor Repeatability Tests

    International Nuclear Information System (INIS)

    Ward, C.R.

    2002-01-01

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility

  11. Ultrasonic Linear Motor with Two Independent Vibrations

    Science.gov (United States)

    Muneishi, Takeshi; Tomikawa, Yoshiro

    2004-09-01

    We propose a new structure of an ultrasonic linear motor in order to solve the problems of high-power ultrasonic linear motors that drive the XY-stage for electron beam equipment and to expand the application fields of the motor. We pay special attention to the following three points: (1) the vibration in two directions of the ultrasonic linear motor should not influence mutually each other, (2) the vibration in two directions should be divided into the stage traveling direction and the pressing direction of the ultrasonic linear motor, and (3) the rigidity of the stage traveling direction of the ultrasonic linear motor should be increased. As a result, the supporting method of ultrasonic linear motors is simplified. The efficiency of the motor is improved and temperature rise is reduced. The stage position drift is also improved.

  12. Simulation of linear Switched Reluctance Motor drives

    OpenAIRE

    Garcia Amoros, Jordi; Blanqué Molina, Balduino; Andrada Gascón, Pedro

    2011-01-01

    This paper presents a simulation model of linear switched reluctance motor drives. A Matlab-Simulink environment coupled with finite element analysis is used to perform the simulations. Experimental and simulation results for a double sided linear switched motor drive prototype are reported and compared to verify the simulation model.

  13. A linear motor as seismic horizontal vibrator

    NARCIS (Netherlands)

    Drijkoningen, G.; Veltman, A.; Hendrix, W.H.A.; Brouwer, J.; Hemstede, A.

    2006-01-01

    In this paper we propose to use the concept of linear synchronous motors to act as a seismic shear-wave vibratory source. We show that a linear motor, even with a design that is not focussed on application of seismic surveying, gives seismic records that are convincing and comparable with an

  14. Linear Motor for Drive of Belt Conveyor

    Directory of Open Access Journals (Sweden)

    Milan Krasl

    2006-01-01

    Full Text Available This paper introduces a novel approach on the design of a linear motor for drive of belt conveyor (LMBC. The motor is a simple combination of asynchronous motor in plane. The electromagnetic forces is one of the most important parameters of electrical machines. This parameter is necessary for the checking of the design. This paper describes several variants: linear motor with slots in platens, slots in one half of platens and optimization of slots. The electromagnetic force can be found with the help of a Finite Elements Method – based program. For solution was used QuickField program.

  15. Comparison of linear synchronous and induction motors

    Science.gov (United States)

    2004-06-01

    A propulsion prade study was conducted as part of the Colorado Maglev Project of FTA's Urban Maglev Technology Development Program to identify and evaluate prospective linear motor designs that could potentially meet the system performance requiremen...

  16. Linear motor with contactless energy transfer

    NARCIS (Netherlands)

    2014-01-01

    An integrated electromagnetic energy conversions device is provided that includes a synchronous or brushless linear (SoBL) motor, and a transformer, where the transformer is integrated electromagnetically and topologically with the SoBL motor, where an electromagnetic field orientation of the

  17. Non-contact ultrasound techniques

    International Nuclear Information System (INIS)

    Khazali Mohd Zin

    2001-01-01

    Non-contact ultrasound plays significant role in material characterisation and inspection. Unlike conventional ultrasonic techniques, non-contact ultrasonic is mostly applicable to areas where the former has its weaknesses and limitations. It is interesting to note that the non-contact ultrasonic technique has an important significant application in industry. The technique is signified by the fact that the object to be inspected is further away from the ultrasonic source, no couplant is needed and inconsistent pressure between the transducer and the specimen can be eliminated. The paper discusses some of the non-contact ultrasound technique and its applications. (Author)

  18. A linear magnetic motor and generator

    Science.gov (United States)

    Studer, P. A.

    1980-01-01

    In linear magnetic motor and generator suitable for remote and hostile environments, magnetic forces drive reciprocating shaft along its axis. Actuator shaft is located in center of cylindrical body and may be supported by either contacting or noncontacting bearings. When device operates as bidirectional motor, drive coil selectively adds and subtracts magnetic flux to and from flux paths, producing forces that drive actuator along axis. When actuator is driven by external reciprocating engine, device becomes ac generator.

  19. Linear ultrasonic motor for absolute gravimeter.

    Science.gov (United States)

    Jian, Yue; Yao, Zhiyuan; Silberschmidt, Vadim V

    2017-05-01

    Thanks to their compactness and suitability for vacuum applications, linear ultrasonic motors are considered as substitutes for classical electromagnetic motors as driving elements in absolute gravimeters. Still, their application is prevented by relatively low power output. To overcome this limitation and provide better stability, a V-type linear ultrasonic motor with a new clamping method is proposed for a gravimeter. In this paper, a mechanical model of stators with flexible clamping components is suggested, according to a design criterion for clamps of linear ultrasonic motors. After that, an effect of tangential and normal rigidity of the clamping components on mechanical output is studied. It is followed by discussion of a new clamping method with sufficient tangential rigidity and a capability to facilitate pre-load. Additionally, a prototype of the motor with the proposed clamping method was fabricated and the performance tests in vertical direction were implemented. Experimental results show that the suggested motor has structural stability and high dynamic performance, such as no-load speed of 1.4m/s and maximal thrust of 43N, meeting the requirements for absolute gravimeters. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Linear Parameter Varying Control of Induction Motors

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    The subject of this thesis is the development of linear parameter varying (LPV) controllers and observers for control of induction motors. The induction motor is one of the most common machines in industrial applications. Being a highly nonlinear system, it poses challenging control problems...... for high performance applications. This thesis demonstrates how LPV control theory provides a systematic way to achieve good performance for these problems. The main contributions of this thesis are the application of the LPV control theory to induction motor control as well as various contributions...

  1. A beam scraper using a linear motor

    International Nuclear Information System (INIS)

    Beadle, E.R.; Rodger, E.S.; Thern, R.E.

    1989-01-01

    A beam scraper using a linear motor drive has been developed for use in the AGS at Brookhaven National Laboratory. The device is used to measure beam size by moving a target to a predetermined location and measuring the intercepted beam with nearby loss monitors or by noting the decrease in the circulating beam current. This device has excellent vacuum characteristics, as the motor and sensor coils are outside the vacuum, coupled magnetically to the moving parts which, are inside. There are no bellows or dynamic seals required. The position-time profile is controlled by a closed-loop servo system which uses position feedback. 2 refs., 4 figs

  2. Non-contact transportation using near-field acoustic levitation

    Science.gov (United States)

    Ueha; Hashimoto; Koike

    2000-03-01

    Near-field acoustic levitation, where planar objects 10 kg in weight can levitate stably near the vibrating plate, is successfully applied both to non-contact transportation of objects and to a non-contact ultrasonic motor. Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured. The theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is also briefly described.

  3. Comparison of Linear Induction Motor Theories for the LIMRV and TLRV Motors

    Science.gov (United States)

    1978-01-01

    The Oberretl, Yamamura, and Mosebach theories of the linear induction motor are described and also applied to predict performance characteristics of the TLRV & LIMRV linear induction motors. The effect of finite motor width and length on performance ...

  4. Linear pneumatic motors – a comparative study

    Directory of Open Access Journals (Sweden)

    Deaconescu Tudor

    2017-01-01

    Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

  5. A seismic vertical vibrator driven by linear synchronous motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Dams, J.; Jenneskens, R.

    2015-01-01

    A linear synchronous motor (LSM) is an electric motor that can produce large controllable forces and is therefore suitable as a driving engine for a seismic vibrator. This motor consists of two independent elements, a magnet track and a coil track, allowing practically unlimited motor displacements.

  6. International program on linear electric motors

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, G.E.; Eastham, A.R.; Parker, J.H.

    1992-05-01

    The International Program on Linear Electric Motors (LEM) was initiated for the purposes of commumication and coordination between various centers of expertise in LEM technology in Germany, Japan and Canada. Furthermore, it was intended to provide assessment and support of the planning of technological developments and for dissemination of information to researchers, service operators and policy makers, and to ensure that full advantage can be taken if opportunities for technology transfer occur. In the process, the program was able to provide closer contacts between researchers, to enhance and encourage collaborative research and development, and to facilitate joint ventures in advanced transportation technologies. Work done under the program is documented, and seminar materials presented by Canadian researchers in Italy, and by Italian researchers at Queen's University in Canada are presented. Five separate abstracts have been prepared for the main body of the report and the seminar materials.

  7. Study of linear induction motor characteristics : the Mosebach model

    Science.gov (United States)

    1976-05-31

    This report covers the Mosebach theory of the double-sided linear induction motor, starting with the ideallized model and accompanying assumptions, and ending with relations for thrust, airgap power, and motor efficiency. Solutions of the magnetic in...

  8. Study of linear induction motor characteristics : the Oberretl model

    Science.gov (United States)

    1975-05-30

    The Oberretl theory of the double-sided linear induction motor (LIM) is examined, starting with the idealized model and accompanying assumptions, and ending with relations for predicted thrust, airgap power, and motor efficiency. The effect of varyin...

  9. PREFACE: Non-contact AFM Non-contact AFM

    Science.gov (United States)

    Giessibl, Franz J.; Morita, Seizo

    2012-02-01

    This special issue is focussed on high resolution non-contact atomic force microscopy (AFM). Non-contact atomic force microscopy was established approximately 15 years ago as a tool to image conducting and insulating surfaces with atomic resolution. Since 1998, an annual international conference has taken place, and although the proceedings of these conferences are a useful source of information, several key developments warrant devoting a special issue to this subject. In the theoretic field, the possibility of supplementing established techniques such as scanning tunneling microscopy (STM) and Kelvin probe microscopy with atomically resolved force micrsoscopy poses many challenges in the calculation of contrast and contrast reversal. The surface science of insulators, self-assembled monolayers and adsorbates on insulators is a fruitful field for the application of non-contact AFM: several articles in this issue are devoted to these subjects. Atomic imaging and manipulation have been pioneered using STM, but because AFM allows the measurement of forces, AFM has had a profound impact in this field as well. Three-dimensional force spectroscopy has allowed many important insights into surface science. In this issue a combined 3D tunneling and force microscopy is introduced. Non-contact AFM typically uses frequency modulation to measure force gradients and was initially used mainly in a vacuum. As can be seen in this issue, frequency modulation is now also used in ambient conditions, allowing better spatial and force resolution. We thank all of the contributors for their time and efforts in making this special issue possible. We are also very grateful to the staff of IOP Publishing for handling the administrative aspects and for steering the refereeing process. Non-contact AFM contents Relation between the chemical force and the tunnelling current in atomic point contacts: a simple model Pavel Jelínek, Martin Ondrácek and Fernando Flores Theoretical simulation of

  10. Quad-copter UAV BLDC Motor Control: Linear v/s non-linear control maps

    Directory of Open Access Journals (Sweden)

    Deep Parikh

    2015-08-01

    Full Text Available This paper presents some investigations and comparison of using linear versus non-linear static motor-control maps for the speed control of a BLDC (Brush Less Direct Current motors used in quad-copter UAV (Unmanned Aerial Vehicles. The motor-control map considered here is the inverse of the static map relating motor-speed output to motor-voltage input for a typical out-runner type Brushless DC Motors (BLDCM.  Traditionally, quad-copter BLDC motor speed control uses simple linear motor-control map defined by the motor-constant specification. However, practical BLDC motors show non-linear characteristic, particularly when operated across wide operating speed-range as is commonly required in quad-copter UAV flight operations. In this paper, our investigations to compare performance of linear versus non-linear motor-control maps are presented. The investigations cover simulation-based and experimental study of BLDC motor speed control systems for  quad-copter vehicle available. First the non-linear map relating rotor RPM to motor voltage for quad-copter BLDC motor is obtained experimentally using an optical speed encoder. The performance of the linear versus non-linear motor-control-maps for the speed control are studied. The investigations also cover study of time-responses for various standard test input-signals e.g. step, ramp and pulse inputs, applied as the reference speed-commands. Also, simple 2-degree of freedom test-bed is developed in our laboratory to help test the open-loop and closed-loop experimental investigations. The non-linear motor-control map is found to perform better in BLDC motor speed tracking control performance and thereby helping achieve better quad-copter roll-angle attitude control.

  11. Lithographic linear motor, lithographic apparatus, and device manufacturing method

    NARCIS (Netherlands)

    2006-01-01

    A linear motor having a high driving force, high efficiency and low normal force comprises two opposed magnet tracks and an armature comprising three open coil sets. The linear motor may be used to drive a stage, such as, for example, a mask or wafer stage, in a lithographic apparatus.

  12. Development of the Floating Centrifugal Pump by Use of Non Contact Magnetic Drive and Its Performance

    Directory of Open Access Journals (Sweden)

    Mitsuo Uno

    2004-01-01

    Full Text Available This article focuses on the impeller construction, non contact driving method and performance of a newly developed shaftless floating pump with centrifugal impeller. The drive principle of the floating impeller pump used the magnet induction method similar to the levitation theory of the linear motor. In order to reduce the axial thrust by the pressure different between shroud and disk side, the balance hole and the aileron blade were installed in the floating impeller. Considering the above effect, floating of an impeller in a pump was realized. Moreover, the performance curves of a developed pump are in agreement with a general centrifugal pump, and the dimensionless characteristic curve also agrees under the different rotational speed due to no mechanical friction of the rotational part. Therefore, utility of a non contacting magnetic-drive style pump with the floating impeller was made clear.

  13. Impact self-excited vibrations of linear motor

    Science.gov (United States)

    Zhuravlev, V. Ph.

    2010-08-01

    Impact self-exciting vibration modes in a linear motor of a monorail car are studied. Existence and stability conditions of self-exciting vibrations are found. Ways of avoiding the vibrations are discussed.

  14. Experimental development of an ultrasonic linear motor

    CSIR Research Space (South Africa)

    M'Boungui, G

    2010-01-01

    Full Text Available the stator structure. In contrast to traditional travelling wave ultrasonic motors, which require two modes to be driven 90° out of phase, only one amplifier is required to drive the proposed device. A prototype device was characterised experimentally...

  15. Linear stability analysis in a solid-propellant rocket motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.M.; Kang, K.T.; Yoon, J.K. [Agency for Defense Development, Taejon (Korea, Republic of)

    1995-10-01

    Combustion instability in solid-propellant rocket motors depends on the balance between acoustic energy gains and losses of the system. The objective of this paper is to demonstrate the capability of the program which predicts the standard longitudinal stability using acoustic modes based on linear stability analysis and T-burner test results of propellants. Commercial ANSYS 5.0A program can be used to calculate the acoustic characteristic of a rocket motor. The linear stability prediction was compared with the static firing test results of rocket motors. (author). 11 refs., 17 figs.

  16. Modelling a linear PM motor including magnetic saturation

    NARCIS (Netherlands)

    Polinder, H.; Slootweg, J.G.; Compter, J.C.; Hoeijmakers, M.J.

    2002-01-01

    The use of linear permanent-magnet (PM) actuators increases in a wide variety of applications because of the high force density, robustness and accuracy. The paper describes the modelling of a linear PM motor applied in, for example, wafer steppers, including magnetic saturation. This is important

  17. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    Science.gov (United States)

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  18. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    Science.gov (United States)

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  19. Comparative analysis of linear motor geometries for Stirling coolers

    Science.gov (United States)

    R, Rajesh V.; Kuzhiveli, Biju T.

    2017-12-01

    Compared to rotary motor driven Stirling coolers, linear motor coolers are characterized by small volume and long life, making them more suitable for space and military applications. The motor design and operational characteristics have a direct effect on the operation of the cooler. In this perspective, ample scope exists in understanding the behavioural description of linear motor systems. In the present work, the authors compare and analyze different moving magnet linear motor geometries to finalize the most favourable one for Stirling coolers. The required axial force in the linear motors is generated by the interaction of magnetic fields of a current carrying coil and that of a permanent magnet. The compact size, commercial availability of permanent magnets and low weight requirement of the system are quite a few constraints for the design. The finite element analysis performed using Maxwell software serves as the basic tool to analyze the magnet movement, flux distribution in the air gap and the magnetic saturation levels on the core. A number of material combinations are investigated for core before finalizing the design. The effect of varying the core geometry on the flux produced in the air gap is also analyzed. The electromagnetic analysis of the motor indicates that the permanent magnet height ought to be taken in such a way that it is under the influence of electromagnetic field of current carrying coil as well as the outer core in the balanced position. This is necessary so that sufficient amount of thrust force is developed by efficient utilisation of the air gap flux density. Also, the outer core ends need to be designed to facilitate enough room for the magnet movement under the operating conditions.

  20. Contact analysis and experimental investigation of a linear ultrasonic motor.

    Science.gov (United States)

    Lv, Qibao; Yao, Zhiyuan; Li, Xiang

    2017-11-01

    The effects of surface roughness are not considered in the traditional motor model which fails to reflect the actual contact mechanism between the stator and slider. An analytical model for calculating the tangential force of linear ultrasonic motor is proposed in this article. The presented model differs from the previous spring contact model, the asperities in contact between stator and slider are considered. The influences of preload and exciting voltage on tangential force in moving direction are analyzed. An experiment is performed to verify the feasibility of this proposed model by comparing the simulation results with the measured data. Moreover, the proposed model and spring model are compared. The results reveal that the proposed model is more accurate than spring model. The discussion is helpful for designing and modeling of linear ultrasonic motors. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Force analysis of linear induction motor for magnetic levitation system

    NARCIS (Netherlands)

    Kuijpers, A.A.; Nemlioglu, C.; Sahin, F.; Verdel, A.J.D.; Compter, J.C.; Lomonova, E.

    2010-01-01

    This paper presents the analyses of thrust and normal forces of linear induction motor (LIM) segments which are implemented in a rotating ring system. To obtain magnetic levitation in a cost effective and sustainable way, decoupled control of thrust and normal forces is required. This study includes

  2. Thermally driven molecular linear motors - A molecular dynamics study

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard Lawrence

    2009-01-01

    We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsule-like nanotube. The simulations indicate that the motion of the capsule can be controlled by th...

  3. CONTRIBUTIONS TO THE FINITE ELEMENT MODELING OF LINEAR ULTRASONIC MOTORS

    Directory of Open Access Journals (Sweden)

    Oana CHIVU

    2013-05-01

    Full Text Available The present paper is concerned with the main modeling elements as produced by means of thefinite element method of linear ultrasonic motors. Hence, first the model is designed and then a modaland harmonic analysis are carried out in view of outlining the main outcomes

  4. Resettable binary latch mechanism for use with paraffin linear motors

    Science.gov (United States)

    Maus, Daryl; Tibbitts, Scott

    1991-01-01

    A new resettable Binary Latch Mechanism was developed utilizing a paraffin actuator as the motor. This linear actuator alternately latches between extended and retracted positions, maintaining either position with zero power consumption. The design evolution and kinematics of the latch mechanism are presented, as well as the development problems and lessons that were learned.

  5. Evaluation of linear induction motor characteristics : the Yamamura model

    Science.gov (United States)

    1975-04-30

    The Yamamura theory of the double-sided linear induction motor (LIM) excited by a constant current source is discussed in some detail. The report begins with a derivation of thrust and airgap power using the method of vector potentials and theorem of...

  6. Position sensor for linear synchronous motors employing halbach arrays

    Science.gov (United States)

    Post, Richard Freeman

    2014-12-23

    A position sensor suitable for use in linear synchronous motor (LSM) drive systems employing Halbach arrays to create their magnetic fields is described. The system has several advantages over previously employed ones, especially in its simplicity and its freedom from being affected by weather conditions, accumulated dirt, or electrical interference from the LSM system itself.

  7. Force measurements on a shielded coreless linear permanent magnet motor

    NARCIS (Netherlands)

    Pluk, K.J.W.; Jansen, J.W.; Lomonova, E.A.

    2014-01-01

    This paper compares force measurements on a shielded coreless linear permanent magnet motor with 2-D models. A 2-D semianalytical modeling method is applied, which is based on Fourier modeling and includes force calculations. The semianalytical modeling correctly predicts the behavior found in the

  8. Bidirectional electrostatic linear shuffle motor with two degrees of freedom

    NARCIS (Netherlands)

    Sarajlic, Edin; Berenschot, Johan W.; Fujita, H.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2005-01-01

    We report on an electrostatic linear inchworm micromotor with two translational degrees-of-freedom. The motor employs built-in mechanical leverage to convert normal deflection of a flexible cross-plate into a small in-plane step and four electrostatic clamps to enable bidirectional inchworm motion

  9. Magnetic shielding for coreless linear permanent magnet motors

    NARCIS (Netherlands)

    Pluk, K.J.W.; Jansen, J.W.; Lomonova, E.

    2013-01-01

    This paper concerns the local reduction of the magnetic flux density by means of magnetic shielding. Using a spatial frequency description, a 2-D semi-analytical periodic model is obtained for a coreless single-sided linear permanent magnet motor. The magnetic shield is included in the modeling

  10. Direct Torque Control With Feedback Linearization for Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Jafarzadeh, Saeed; Fadali, Sami M.

    2017-01-01

    This paper describes a direct-torque-controlled (DTC) induction motor (IM) drive that employs feedback linearization and sliding-mode control (SMC). A new feedback linearization approach is proposed, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude....... This intuitive linear model is used to implement a DTC-type controller that preserves all DTC advantages and eliminates its main drawback, the flux and torque ripple. Robust, fast, and ripple-free control is achieved by using SMC with proportional control in the vicinity of the sliding surface. SMC assures...... in simulations. The sliding controller is compared with a linear DTC scheme with and without feedback linearization. Extensive experimental results for a sensorless IM drive validate the proposed solution....

  11. Advanced analysis technique for the evaluation of linear alternators and linear motors

    Science.gov (United States)

    Holliday, Jeffrey C.

    1995-01-01

    A method for the mathematical analysis of linear alternator and linear motor devices and designs is described, and an example of its use is included. The technique seeks to surpass other methods of analysis by including more rigorous treatment of phenomena normally omitted or coarsely approximated such as eddy braking, non-linear material properties, and power losses generated within structures surrounding the device. The technique is broadly applicable to linear alternators and linear motors involving iron yoke structures and moving permanent magnets. The technique involves the application of Amperian current equivalents to the modeling of the moving permanent magnet components within a finite element formulation. The resulting steady state and transient mode field solutions can simultaneously account for the moving and static field sources within and around the device.

  12. Analysis of the linear induction motor in transient operation

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, G; Rotondale, N; Scarano, M

    1987-05-01

    The paper deals with the analysis of a bilateral linear induction motor in transient operation. We have considered an impressed voltage one-dimensional model which takes into account end effects. The real winding distribution of the armature has been represented as a lumped parameters system. By using the space vectors methodology, the partial differential equation of the sheet is solved bythe variable separation method. Therefore it's possible to arrange a system of ordinary differential equations where the unknown quantities are the space vectors of the air-gap flux density and sheet currents. Finally, we have analyzed the characteristic quantities for a no-load starting of small power motors.

  13. A novel linear switched reluctance motor for railway transportation systems

    International Nuclear Information System (INIS)

    Daldaban, Ferhat; Ustkoyuncu, Nurettin

    2010-01-01

    This paper presents the design and realization of a new linear switched reluctance motor (LSRM) structure, especially suitable for high-speed railway systems. The new model has a double active stator configuration and provides high force for many applications with low cost. The characteristics of the LSRM are obtained by using finite element analysis (FEA) and analytical calculations. The results of the FEA and analytical calculations are presented, and compared with experimental results. In addition, a classical double-sided LSRM (DSLSRM) is modeled with the same specifications of the new motor structure and the results are compared.

  14. Development of a linear induction motor based artificial muscle system.

    Science.gov (United States)

    Gruber, A; Arguello, E; Silva, R

    2013-01-01

    We present the design of a linear induction motor based on electromagnetic interactions. The engine is capable of producing a linear movement from electricity. The design consists of stators arranged in parallel, which produce a magnetic field sufficient to displace a plunger along its axial axis. Furthermore, the winding has a shell and cap of ferromagnetic material that amplifies the magnetic field. This produces a force along the length of the motor that is similar to that of skeletal muscle. In principle, the objective is to use the engine in the development of an artificial muscle system for prosthetic applications, but it could have multiple applications, not only in the medical field, but in other industries.

  15. Linear motor driven Stirling coolers for military and commercial applications

    International Nuclear Information System (INIS)

    Berry, R.

    1992-01-01

    This paper discusses the design and performance of a miniature, closed cycle, split stirling, cryogenic cooler that provides 1 watt of cooling at 80 K. The compressor uses two opposed linear motors to drive opposed pistons and the expander uses a pneumatically driven displacer. A single electronics module and compressor has been developed to drive three different expanders that have nominal cold cylinder diameters of 5, 8 and 13 mm

  16. Generate stepper motor linear speed profile in real time

    Science.gov (United States)

    Stoychitch, M. Y.

    2018-01-01

    In this paper we consider the problem of realization of linear speed profile of stepper motors in real time. We considered the general case when changes of speed in the phases of acceleration and deceleration are different. The new and practical algorithm of the trajectory planning is given. The algorithms of the real time speed control which are suitable for realization to the microcontroller and FPGA circuits are proposed. The practical realization one of these algorithms, using Arduino platform, is given also.

  17. Electromagnetic Energy Converters - Rotating Motors and Linear Generators

    Energy Technology Data Exchange (ETDEWEB)

    Ekergaard, Boel

    2011-07-01

    This licentiate thesis presents a study of the electromagnetic properties of linear synchronous permanent magnet generators, utilized in wave energy converters, and a two pole permanent magnet motor for an electrical vehicle. Both machine topologies are presented, designed with a numerical simulation tool, based on a model derived from Maxwell's equations. Full scale prototypes of both the machines are under construction. A continued study about the impact on the magnetic circuit caused by the longitudinal ends of a linear generator is performed. The results present significant core losses in the translator and an increased cogging force caused by the longitudinal ends. Further, a new electric conversion circuit based on the electric resonance phenomena is presented. Experimental results indicate that a successful electric resonance between the generator and external circuit has been achieved. Finally, detailed analytical and numerical methods are utilized to investigate the losses in the two pole permanent magnet motor over a wide frequency interval. The results indicate that the efficiency of electrical motors in electrical vehicle system can be increased relative existing designs and argue for limiting of the gearbox. The system total efficiency and mechanical stability can thereby be increased. The work concerning the wave energy converter is a part of a larger project, the so called Lysekil Wave Power Project, whereas the work concerning the electric motor so far has been carried out as an individual project. However, a future goal is to integrate the research on the electric motor for electrical vehicle with closely related ongoing research regarding a flywheel based electric driveline for an All Electric Propulsion System

  18. Design and optimization of a modal- independent linear ultrasonic motor.

    Science.gov (United States)

    Zhou, Shengli; Yao, Zhiyuan

    2014-03-01

    To simplify the design of the linear ultrasonic motor (LUSM) and improve its output performance, a method of modal decoupling for LUSMs is proposed in this paper. The specific embodiment of this method is decoupling of the traditional LUSM stator's complex vibration into two simple vibrations, with each vibration implemented by one vibrator. Because the two vibrators are designed independently, their frequencies can be tuned independently and frequency consistency is easy to achieve. Thus, the method can simplify the design of the LUSM. Based on this method, a prototype modal- independent LUSM is designed and fabricated. The motor reaches its maximum thrust force of 47 N, maximum unloaded speed of 0.43 m/s, and maximum power of 7.85 W at applied voltage of 200 Vpp. The motor's structure is then optimized by controlling the difference between the two vibrators' resonance frequencies to reach larger output speed, thrust, and power. The optimized results show that when the frequency difference is 73 Hz, the output force, speed, and power reach their maximum values. At the input voltage of 200 Vpp, the motor reaches its maximum thrust force of 64.2 N, maximum unloaded speed of 0.76 m/s, maximum power of 17.4 W, maximum thrust-weight ratio of 23.7, and maximum efficiency of 39.6%.

  19. Improvement of the thermal behavior of linear motors through insulation layer

    International Nuclear Information System (INIS)

    Eun, I. U.; Lee, C. M.; Chung, W. J.; Choi, Y. H.

    2001-01-01

    Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools, because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force are measured and analyzed. To improve the thermal stiffness of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented

  20. Dynamic Response Analysis of Linear Pulse Motor with Closed Loop Control

    OpenAIRE

    山本, 行雄; 山田, 一

    1989-01-01

    A linear pulse motor can translate digital signals into linear positions without a gear system. It is important to predict a dynamic response in order to the motor that has the good performance. In this report the maximum pulse rate and the maximum speed on the linear pulse motor are obtained by using the sampling theory.

  1. NASTRAN buckling study of a linear induction motor reaction rail

    Science.gov (United States)

    Williams, J. G.

    1973-01-01

    NASTRAN was used to study problems associated with the installation of a linear induction motor reaction rail test track. Specific problems studied include determination of the critical axial compressive buckling stress and establishment of the lateral stiffness of the reaction rail under combined loads. NASTRAN results were compared with experimentally obtained values and satisfactory agreement was obtained. The reaction rail was found to buckle at an axial compressive stress of 11,400 pounds per square inch. The results of this investigation were used to select procedures for installation of the reaction rail.

  2. Cortical Contribution to Linear, Non-linear and Frequency Components of Motor Variability Control during Standing.

    Science.gov (United States)

    König Ignasiak, Niklas; Habermacher, Lars; Taylor, William R; Singh, Navrag B

    2017-01-01

    Motor variability is an inherent feature of all human movements and reflects the quality of functional task performance. Depending on the requirements of the motor task, the human sensory-motor system is thought to be able to flexibly govern the appropriate level of variability. However, it remains unclear which neurophysiological structures are responsible for the control of motor variability. In this study, we tested the contribution of cortical cognitive resources on the control of motor variability (in this case postural sway) using a dual-task paradigm and furthermore observed potential changes in control strategy by evaluating Ia-afferent integration (H-reflex). Twenty healthy subjects were instructed to stand relaxed on a force plate with eyes open and closed, as well as while trying to minimize sway magnitude and performing a "subtracting-sevens" cognitive task. In total 25 linear and non-linear parameters were used to evaluate postural sway, which were combined using a Principal Components procedure. Neurophysiological response of Ia-afferent reflex loop was quantified using the Hoffman reflex. In order to assess the contribution of the H-reflex on the sway outcome in the different standing conditions multiple mixed-model ANCOVAs were performed. The results suggest that subjects were unable to further minimize their sway, despite actively focusing to do so. The dual-task had a destabilizing effect on PS, which could partly (by 4%) be counter-balanced by increasing reliance on Ia-afferent information. The effect of the dual-task was larger than the protective mechanism of increasing Ia-afferent information. We, therefore, conclude that cortical structures, as compared to peripheral reflex loops, play a dominant role in the control of motor variability.

  3. Analysis of Nonlinear Dynamics in Linear Compressors Driven by Linear Motors

    Science.gov (United States)

    Chen, Liangyuan

    2018-03-01

    The analysis of dynamic characteristics of the mechatronics system is of great significance for the linear motor design and control. Steady-state nonlinear response characteristics of a linear compressor are investigated theoretically based on the linearized and nonlinear models. First, the influence factors considering the nonlinear gas force load were analyzed. Then, a simple linearized model was set up to analyze the influence on the stroke and resonance frequency. Finally, the nonlinear model was set up to analyze the effects of piston mass, spring stiffness, driving force as an example of design parameter variation. The simulating results show that the stroke can be obtained by adjusting the excitation amplitude, frequency and other adjustments, the equilibrium position can be adjusted by adjusting the DC input, and to make the more efficient operation, the operating frequency must always equal to the resonance frequency.

  4. Commercializing a U.S. piezoceramic linear motor

    Science.gov (United States)

    Diehl, Rick W.

    2000-06-01

    A small low-cost piezoceramic linear motor has been developed in the US and is being commercialized by EDO Corporation, working with a leading motion control OEM and with a prominent US corporate research laboratory. First generation motor design has emphasized high displacement at up to 200mm per second velocity with 3.5 Newtons force with high resolution, short time constant and a 15 volt power supply at a cost of less than 100 dollars. Motor dimensions of 30 by 50 by 4 mm allow broad configuration choices, al hidden within the motion control slide. The EDO approach was to build on its core competence in high reliability electroceramic material engineering and production, and to use a strategy of back-integrating, or outsourcing of recent advances outside Edo in piezoceramics, while forward- integrating into specific emerging applications known intimately by the OEM in the market. The strategy provided design focus that has led to a cost-effective advance in 'solid-state actuation and control'. This is considered a classic case of successful industrial integration of an enabling technology across organizations in order to access the needed mix of technology for development of an innovative and competitive solution.

  5. Linear magnetic spring and spring/motor combination

    Science.gov (United States)

    Patt, Paul J. (Inventor); Stolfi, Fred R. (Inventor)

    1991-01-01

    A magnetic spring, or a spring and motor combination, providing a linear spring force characteristic in each direction from a neutral position, in which the spring action may occur for any desired coordinate of a typical orthogonal coordinate system. A set of magnets are disposed, preferably symmetrically about a coordinate axis, poled orthogonally to the desired force direction. A second set of magnets, respectively poled opposite the first set, are arranged on the sprung article. The magnets of one of the sets are spaced a greater distance apart than those of the other, such that an end magnet from each set forms a pair having preferably planar faces parallel to the direction of spring force, the faces being offset so that in a neutral position the outer edge of the closer spaced magnet set is aligned with the inner edge of the greater spaced magnet set. For use as a motor, a coil can be arranged with conductors orthogonal to both the magnet pole directions and the direction of desired spring force, located across from the magnets of one set and fixed with respect to the magnets of the other set. In a cylindrical coordinate system having axial spring force, the magnets are radially poled and motor coils are concentric with the cylinder axis.

  6. The linear electric motor: Instability at 1,000 g's

    International Nuclear Information System (INIS)

    Hunter, S.

    1997-01-01

    When fluid of high density is supported against gravity by a less dense liquid, the system is unstable, and microscopic perturbations grow at the interface between the fluids. This phenomenon, called the Rayleigh-Taylor instability, also occurs when a bottle of oil-and-vinegar salad dressing is turned upside down. The instability causes spikes of the dense fluid to penetrate the light fluid, while bubbles of the lighter fluid rise into the dense fluid. The same phenomenon occurs when a light fluid is used to accelerate a dense fluid, causing the two fluids to mix at a very high rate. For example, during the implosion of an ICF capsule, this instability can cause enough mixing to contaminate, cool, and degrade the yield of the thermonuclear fuel. The LEM is an excellent tool for studying this instability, but what is it? Think of a miniature high-speed electric train (the container) hurtling down a track (the electrodes) while diagnostic equipment (optical and laser) photographs it. The LEM, consists of four linear electrodes, or rails, that carry an electrical current to a pair of sliding armatures on the container. A magnetic field is produced that works in concert with the rail-armature current to accelerate the container--just as in an electric motor, but in a linear fashion rather than in rotation. The magnetic field is augmented with elongated coils just as in a conventional electric motor. This configuration also helps hold the armatures against the electrodes to prevent arcing. The electrical energy (0.6 megajoules) is provided by 16 capacitor banks that can be triggered independently to produce different acceleration profiles (i.e., how the acceleration varies with time)

  7. EPro Non-contact erosion profiling

    DEFF Research Database (Denmark)

    Meinert, Palle

    Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal was to aut......Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal...... was to automate the measuring of profiles in order to save manpower and to increase the number of possible measure points. Additional requirement was that measurements should be done in a non-contact way and that the measuring should not be hindered by the presence of water....

  8. An efficient linear power generator - Linear motor for oscillating piston machines; Effizienter Lineargenerator / Linearmotor fuer Kolbenmaschine - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Lindegger, M.

    2008-07-01

    When an oscillating piston interacts with an electrical generator or motor, it is obvious that the electrical machine should also have linear motion, eliminating the disadvantage of a crankshaft. This work has two parts: construction of an efficient linear generator for a Stirling engine with a free piston and a theoretical study of the efficiency of linear motors for driving compressors. The Stirling engine and the linear generator have a continuous power of 1.3 kW{sub el}. With thermal peak power the planned 1.5 kW{sub el} are attained. The Project 'Stirling Free Piston Generator' for cogeneration will continue. Smaller linear motors with permanent magnets function without electronic control from single-phase AC net. The theoretical study shows how linear motors can be led out by linking the electric vector diagram with the pressure-volume diagram of the compressor. At a power level exceeding a few kW, a three-phase system with power electronics is more suitable. The frequency of oscillation is variable and lower than 50 Hz. The efficiency of the simulated linear motors lies in the range of efficiency class EFF1 of standard motors. The very high efficiencies of rotating motors with permanent magnets are not attained. The combination of the linear motor with an optimised thermal process leads to advantages regarding the efficiency. If a heat pump with linear drive system can operate with hot lubricating oil the losses in the heat exchangers are reduced. The Competence Center for Thermal Machines at Lucerne University of Applied Sciences and Arts shows great interest to pursue the project of a linear heat pump for small temperature differences. (author)

  9. Low-Rank Linear Dynamical Systems for Motor Imagery EEG.

    Science.gov (United States)

    Zhang, Wenchang; Sun, Fuchun; Tan, Chuanqi; Liu, Shaobo

    2016-01-01

    The common spatial pattern (CSP) and other spatiospectral feature extraction methods have become the most effective and successful approaches to solve the problem of motor imagery electroencephalography (MI-EEG) pattern recognition from multichannel neural activity in recent years. However, these methods need a lot of preprocessing and postprocessing such as filtering, demean, and spatiospectral feature fusion, which influence the classification accuracy easily. In this paper, we utilize linear dynamical systems (LDSs) for EEG signals feature extraction and classification. LDSs model has lots of advantages such as simultaneous spatial and temporal feature matrix generation, free of preprocessing or postprocessing, and low cost. Furthermore, a low-rank matrix decomposition approach is introduced to get rid of noise and resting state component in order to improve the robustness of the system. Then, we propose a low-rank LDSs algorithm to decompose feature subspace of LDSs on finite Grassmannian and obtain a better performance. Extensive experiments are carried out on public dataset from "BCI Competition III Dataset IVa" and "BCI Competition IV Database 2a." The results show that our proposed three methods yield higher accuracies compared with prevailing approaches such as CSP and CSSP.

  10. Optimization of a piezoelectric linear motor in terms of the contact parameters

    International Nuclear Information System (INIS)

    Ko, Hyun-Phill; Kim, Sangsig; Kang, Chong-Yun; Kim, Hyun-Jai; Yoon, Seok-Jin

    2005-01-01

    The contact kinetics of piezoelectric linear motors determines the operational characteristics like speed and torque or transmitted mechanical power and efficiency. Piezoelectric linear motors are driven by tangential stress in the interface between tip of shaking beam and slider. A good contact between the tip and slider is necessary for a reliable analysis of the motor, which is needed for the optimization of its performance. The piezoelectric linear motor was fabricated and the characteristics of the motor were investigated by external conditions such as tip shape with different curvatures and contact force between the tip and the slider. It was found in this investigation that the optimal curvature of the tip and the contact force are curvature of 1 and 10, respectively, for the high actuating speed, and curvature of 1 and 40 N, respectively, for the high actuating force. Finally, tip shape has an influence on the characteristics of linear motor

  11. Analysis and Design of Double-sided Air core Linear Servo Motor with Trapezoidal Permanent Magnets

    DEFF Research Database (Denmark)

    Zhang, Yuqiu; Yang, Zilong; Yu, Minghu

    2011-01-01

    In order to reduce the thrust ripple of linear servo system, a double-sided air core permanent magnet linear servo motor with trapezoidal shape permanent magnets (TDAPMLSM) is proposed in this paper. An analytical model of the motor for predicting the magnetic field in the air-gap at no...

  12. Design of linear pulse motor for control element drive mechanism of SMART

    International Nuclear Information System (INIS)

    Kim, J. H.; Huh, H.; Kim, J. I.; Jang, M. H.; Kang, D. H.

    1999-01-01

    49 Control Rod Drive Mechanisms(CEDMs) are densely installed on the reactor central head of SMART. The structural design should ensure the space for maintenance/repair, cable routing, and heat release from the motor. In this paper, an improved design is presented to enlarge the space between CEDMs by decreasing the diameter of linear pulse motor. The reduction of motor thrust force due to the decrease of the motor diameter is compensated by resizing the other structural components

  13. Direct torque control via feedback linearization for permanent magnet synchronous motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2012-01-01

    The paper describes a direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drive that employs feedback linearization and uses sliding-mode and linear controllers. We introduce a new feedback linearization approach that yields a decoupled linear PMSM model with two state...

  14. A Study on the Design of PM Exited Transverse Flux Linear Motor for Ropeless Elevator

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Hyun; Bang, Deok Je; Kim, Jong Moo; Jeong, Yeon Ho [Korea Electrotechnology Research Institute (Korea); Kim, Moon Hwan [Silla University (Korea)

    2000-03-01

    The topological investigations regarding magnetic circuit geometry and winding form of the transverse flux machine have brought up a variety of constructable arrangements with different features for several types of application[1, 2]. Here with, a novel PM-exited linear motor with inner mover, based on the transverse flux configuration leads to a considerable increase in power density for moving part. In this study we designed PM-exited transverse flux linear motor for ropeless elevator, whose output power density is higher and weight is lighter than conventional linear synchronous motors, When the designed motor in this study is applied to ropeless elevator, it is possible to increase power density more than 400% comparing with PM exited linear synchronous motor. The result of this study can be utilized for ropeless elevator or gearless direct linear moving system with high output[3]. (author). 8 refs., 9 figs., 4 tabs.

  15. A square-plate ultrasonic linear motor operating in two orthogonal first bending modes.

    Science.gov (United States)

    Chen, Zhijiang; Li, Xiaotian; Chen, Jianguo; Dong, Shuxiang

    2013-01-01

    A novel square-plate piezoelectric ultrasonic linear motor operated in two orthogonal first bending vibration modes (B₁) is proposed. The piezoelectric vibrator of the linear motor is simply made of a single PZT ceramic plate (sizes: 15 x 15 x 2 mm) and poled in its thickness direction. The top surface electrode of the square ceramic plate was divided into four active areas along its two diagonal lines for exciting two orthogonal B₁ modes. The achieved driving force and speed from the linear motor are 1.8 N and 230 mm/s, respectively, under one pair orthogonal voltage drive of 150 V(p-p) at the resonance frequency of 92 kHz. The proposed linear motor has advantages over conventional ultrasonic linear motors, such as relatively larger driving force, very simple working mode and structure, and low fabrication cost.

  16. Influence analysis of structural parameters on electromagnetic properties of HTS linear induction motor

    International Nuclear Information System (INIS)

    Zhao, J.; Zheng, T.Q.; Zhang, W.; Fang, J.; Liu, Y.M.

    2011-01-01

    A new type high temperature superconductor linear induction motor is designed and analyzed as a prototype to ensure applicability aimed at industrial motors. Made of Bi-2223/Ag, primary windings are distributed with the double-layer concentrated structure. The motor is analyzed by 2D electromagnetic Finite Element Method to get magnetic field distribution, thrust force, vertical force and so on. The critical current of motor and the electromagnetic force are mostly decided by the leakage flux density of primary slot and by the main magnetic flux and eddy current respectively. The structural parameters of motor have a great influence on the distribution of magnetic field. Under constant currents, the properties of motor are analyzed with different slot widths, slot heights and winding turns. The properties of motor, such as the maximum slot leakage flux density, motor thrust and motor vertical force, are analyzed with different structural parameters.

  17. Analysis of Non-contact Acousto Thermal Signature Data (Postprint)

    Science.gov (United States)

    2016-02-01

    AFRL-RX-WP-JA-2016-0321 ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) Amanda K. Criner AFRL/RX...October 2014 – 16 September 2015 4. TITLE AND SUBTITLE ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) 5a. CONTRACT NUMBER...words) The non-contact acousto-thermal signature (NCATS) is a nondestructive evaluation technique with potential to detect fatigue in materials such as

  18. Clinical tonometric measurements comparing three non-contact tonometers.

    Science.gov (United States)

    Walby, M A; Augsburger, A; Polasky, M

    1975-06-01

    Three American Optical Non-contact Tonometers were used to compare readings against each other. The attempt was to determine if all three tonometers were measuring the same IOP over a wide range of pressures. The assumption in practice is that all Non-contact Tonometers are manufactured within tolerance that should allow the examiner to find that same IOP on a patient regardless of the Non-contact Tonometer used. A preliminary study found no significant difference between the instruments.

  19. Design and performance testing of an ultrasonic linear motor with dual piezoelectric actuators.

    Science.gov (United States)

    Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Laoratanakul, Pitak; Muensit, Nantakan

    2012-05-01

    In this work, design and performance testing of an ultrasonic linear motor with dual piezoelectric actuator patches are studied. The motor system consists of a linear stator, a pre-load weight, and two piezoelectric actuator patches. The piezoelectric actuators are bonded with the linear elastic stator at specific locations. The stator generates propagating waves when the piezoelectric actuators are subjected to harmonic excitations. Vibration characteristics of the linear stator are analyzed and compared with finite element and experimental results. The analytical, finite element, and experimental results show agreement. In the experiments, performance of the ultrasonic linear motor is tested. Relationships between velocity and pre-load weight, velocity and applied voltage, driving force and applied voltage, and velocity and driving force are reported. The design of the dual piezoelectric actuators yields a simpler structure with a smaller number of actuators and lower stator stiffness compared with a conventional design of an ultrasonic linear motor with fully laminated piezoelectric actuators.

  20. Traveling-wave piezoelectric linear motor part II: experiment and performance evaluation.

    Science.gov (United States)

    Ting, Yung; Li, Chun-Chung; Chen, Liang-Chiang; Yang, Chieh-Min

    2007-04-01

    This article continues the discussion of a traveling-wave piezoelectric linear motor. Part I of this article dealt with the design and analysis of the stator of a traveling-wave piezoelectric linear motor. In this part, the discussion focuses on the structure and modeling of the contact layer and the carriage. In addition, the performance analysis and evaluation of the linear motor also are dealt with in this study. The traveling wave is created by stator, which is constructed by a series of bimorph actuators arranged in a line and connected to form a meander-line structure. Analytical and experimental results of the performance are presented and shown to be almost in agreement. Power losses due to friction and transmission are studied and found to be significant. Compared with other types of linear motors, the motor in this study is capable of supporting heavier loads and provides a larger thrust force.

  1. Linear summation of outputs in a balanced network model of motor cortex.

    Science.gov (United States)

    Capaday, Charles; van Vreeswijk, Carl

    2015-01-01

    Given the non-linearities of the neural circuitry's elements, we would expect cortical circuits to respond non-linearly when activated. Surprisingly, when two points in the motor cortex are activated simultaneously, the EMG responses are the linear sum of the responses evoked by each of the points activated separately. Additionally, the corticospinal transfer function is close to linear, implying that the synaptic interactions in motor cortex must be effectively linear. To account for this, here we develop a model of motor cortex composed of multiple interconnected points, each comprised of reciprocally connected excitatory and inhibitory neurons. We show how non-linearities in neuronal transfer functions are eschewed by strong synaptic interactions within each point. Consequently, the simultaneous activation of multiple points results in a linear summation of their respective outputs. We also consider the effects of reduction of inhibition at a cortical point when one or more surrounding points are active. The network response in this condition is linear over an approximately two- to three-fold decrease of inhibitory feedback strength. This result supports the idea that focal disinhibition allows linear coupling of motor cortical points to generate movement related muscle activation patterns; albeit with a limitation on gain control. The model also explains why neural activity does not spread as far out as the axonal connectivity allows, whilst also explaining why distant cortical points can be, nonetheless, functionally coupled by focal disinhibition. Finally, we discuss the advantages that linear interactions at the cortical level afford to motor command synthesis.

  2. Mathematical models of flat linear induction motors used in mining drives

    Energy Technology Data Exchange (ETDEWEB)

    Tall, M

    1984-01-01

    Design parameters are calculated for electric flat linear induction motors, widely employed in the coal and ore mining industries in Poland. A mathematical model of this motor with a single-layer ferromagnetic secondary part is presented. A three-dimensional electromagnetic field analysis is carried out, taking relative magnetic permeability variation, discrete winding distribution, influence of armature grooving and pulsating field influence into account. A computer calculation algorithm is proposed for determining motor characteristics. 17 refs.

  3. Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics

    Science.gov (United States)

    1972-03-01

    A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...

  4. A standing wave linear ultrasonic motor operating in in-plane expanding and bending modes.

    Science.gov (United States)

    Chen, Zhijiang; Li, Xiaotian; Ci, Penghong; Liu, Guoxi; Dong, Shuxiang

    2015-03-01

    A novel standing wave linear ultrasonic motor operating in in-plane expanding and bending modes was proposed in this study. The stator (or actuator) of the linear motor was made of a simple single Lead Zirconate Titanate (PZT) ceramic square plate (15 × 15 × 2 mm(3)) with a circular hole (D = 6.7 mm) in the center. The geometric parameters of the stator were computed with the finite element analysis to produce in-plane bi-mode standing wave vibration. The calculated results predicted that a driving tip attached at midpoint of one edge of the stator can produce two orthogonal, approximate straight-line trajectories, which can be used to move a slider in linear motion via frictional forces in forward or reverse direction. The investigations showed that the proposed linear motor can produce a six times higher power density than that of a previously reported square plate motor.

  5. Coreless Linear Induction Motor (LIM) for Space-borne Electro-magnetic Mass Driver Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Large scale linear induction motors use ferromagnetic cores, but at high speed these cores choke the system’s ability to transform electrical energy into mechanical...

  6. Linear estimation discriminates midline sources and motor cortex contribution to the readiness potential

    NARCIS (Netherlands)

    Knosche, Thomas; Knosche, T.R.; Praamstra, Peter; Peters, M.J.; Stegeman, Dick; Stegeman, D.

    1996-01-01

    Spatiotemporal dipole modelling of the generators of the readiness potential (RP) prior to voluntary movements has yielded diverging results concerning the contributions of supplementary motor area (SMA) and primary motor cortex. We applied an alternative approach (i.e. linear estimation theory) to

  7. MAGNETIC INDUCTION DISTRIBUTION IN A LINEAR SYNCHRONUS MOTOR WITH MAGNETIC SUSPENSION

    Directory of Open Access Journals (Sweden)

    D.I. Parkhomenko

    2013-02-01

    Full Text Available Results of computer simulation and experimental investigations of magnetic induction distribution in a coaxial linear synchronous motor with magnetic suspension are presented. The magnetic induction distribution has been studied both in the motor air gap and on the runner surface.

  8. Study on a high thrust force bi-double-sided permanent magnet linear synchronous motor

    Directory of Open Access Journals (Sweden)

    Liang Tong

    2016-03-01

    Full Text Available A high thrust force bi-double-sided permanent magnet linear synchronous motor used in gantry-type five-axis machining center is designed and its performance was tested in this article. This motor is the subproject of Chinese National Science and Technology Major Project named as “development of domestic large thrust linear motor used in high-speed gantry-type five-axis machining center project” jointly participated by enterprises and universities. According to the requirement of the application environment and motor performance parameters, the linear motor’s basic dimensions, form of windings, and magnet arrangement are preliminarily specified through theoretical analysis and calculation. To verify the correctness of the result of the calculation, the finite element model of the motor is established. The static and dynamic characteristics of the motor are studied and analyzed through the finite element method, and the initial scheme is revised. The prototype of the motor is manufactured based on the final revised structure parameters, and the performance of the motor is fully tested using the evaluation platform for direct-drive motor component. Experimental test results meet the design requirements and show the effectiveness of design method and process.

  9. Fluid powered linear piston motor with harmonic coupling

    Science.gov (United States)

    Raymond, David W.

    2016-09-20

    A motor is disclosed that includes a module assembly including a piston that is axially cycled. The piston axial motion is coupled to torque couplers that convert the axial motion into rotary motion. The torque couplers are coupled to a rotor to rotate the rotor.

  10. A T-shape linear piezoelectric motor with single foot.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Yang, Xiaohui; Liu, Junkao

    2015-02-01

    A new T-shape piezoelectric motor using the hybrid of two orthogonal longitudinal vibrations is proposed in this work. Six pieces of PZT ceramic plates are bonded on the upside and downside surfaces of a T-shape duralumin alloy base respectively to form the proposed motor. Elliptical movement can be generated on the driving tip by applying sine and cosine voltages to the PZT elements. The horizontal displacement of the driving tip will push the runner while the vertical displacement can overcome the preload. Finite element method is used to accomplish the design and analysis process. The resonance frequencies of the two vibration modes are tuned to be close by modal analysis, while the motion trajectory of the driving tip is observed by transient analysis. After the fabrication of a prototype, the vibration characteristics and mechanical output ability are measured. The no-load speed and the maximum output thrust force of the proposed motor are tested to be 718 mm/s and 3.5 N under an exciting frequency of 53.1 kHz. The proposed T-shape piezoelectric motor exhibits merits of simple structure, easy to realize miniaturization, easy to be fabricated, and high power-to-weight ratio. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Development of a sub-nanometer positioning device: combining a new linear motor with linear motion ball guide ways

    International Nuclear Information System (INIS)

    Otsuka, J; Tanaka, T; Masuda, I

    2010-01-01

    A new type of linear motor described in this note has some advantages compared with conventional motors. The attractive magnetic force between the stator (permanent magnets) and mover (armature) is diminished almost to zero. The efficiency is better because the magnetic flux leakage is very small, the size of motor is smaller and detent (force ripple) is smaller than for conventional motors. Therefore, we think that this motor is greatly suitable for ultra-precision positioning as an actuator. An ultra-precision positioning device using this motor and linear motion ball guide ways is newly developed by making the device very rigid and using a suitable control method. Moreover, the positioning performance is evaluated by a positioning resolution, and deviation and dispersion errors. As a result of repeated step response tests, the positioning resolution is 0.3 nm, with the deviation error and dispersion error (3σ) being sub-nanometer. Consequently, the positioning device achieves sub-nanometer positioning. (technical design note)

  12. Principle and analysis of a linear motor driving system for HTS levitation applications

    International Nuclear Information System (INIS)

    Jin, Jian X.; Guo, You G.; Zhu, Jian G.

    2007-01-01

    High temperature superconductor (HTS) high levitation force density with passive and self-stabilizing features allows a number of special applications to be developed. Linear motor driving systems are commonly required for those applications such as levitated transport systems. In this paper a prototype linear motor driving system with HTS is analyzed with calculation details including its magnetic fields and driving forces presented in the paper

  13. Direct torque control with feedback linearization for induction motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Jafarzadeh, Saeed; Fadali, Sami M.

    2015-01-01

    This paper describes a Direct Torque Controlled (DTC) Induction Machine (IM) drive that employs feedback linearization and sliding-mode control. A feedback linearization approach is investigated, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude....... This intuitive linear model is used to implement a DTC type controller that preserves all DTC advantages and eliminates its main drawback, the flux and torque ripple. Robust, fast, and ripple-free control is achieved by using Variable Structure Control (VSC) with proportional control in the vicinity...... robust stability analysis are presented. The sliding controller is compared with a linear DTC scheme, and experimental results for a sensorless IM drive validate the proposed solution....

  14. A double B1-mode 4-layer laminated piezoelectric linear motor.

    Science.gov (United States)

    Li, Xiaotian; Chen, Zhijiang; Dong, Shuxiang

    2012-12-01

    We report a miniature piezoelectric ultrasonic linear motor that is made of four Pb(Zr,Ti)O(3) (PZT) piezoelectric ceramic layers for low-voltage work. The 4-layer piezoelectric laminate works in two orthogonal first-bending modes for producing elliptical oscillations, which are then used to drive a contacting slider into continuous linear motion. Experimental results show that the miniature linear motor (size: 4 × 4 × 12 mm, weight: 1.7 g) can generate a large driving force of 0.48 N and a linear motion speed of up to 160 mm/s, using a 40 V(pp)/mm voltage drive at its resonance frequency of 64.5 kHz. The maximum efficiency of the linear motor is 30%.

  15. Evaluation of synthetic linear motor-molecule actuation energetics

    OpenAIRE

    Brough, Branden; Northrop, Brian H.; Schmidt, Jacob J.; Tseng, Hsian-Rong; Houk, Kendall N.; Stoddart, J. Fraser; Ho, Chih-Ming

    2006-01-01

    By applying atomic force microscope (AFM)-based force spectroscopy together with computational modeling in the form of molecular force-field simulations, we have determined quantitatively the actuation energetics of a synthetic motor-molecule. This multidisciplinary approach was performed on specifically designed, bistable, redox-controllable [2]rotaxanes to probe the steric and electrostatic interactions that dictate their mechanical switching at the single-molecule level. The fusion of expe...

  16. Stepping motor adaptor actuator for a commercial uhv linear motion feedthrough

    International Nuclear Information System (INIS)

    Iarocci, M.; Oversluizen, T.

    1989-01-01

    An adaptor coupling has been developed that will allow the attachment of a standard stepping motor to a precision commercial (Varian) uhv linear motion feedthrough. The assembly, consisting of the motor, motor adaptor, limit switches, etc. is clamped to the feedthrough body which can be done under vacuum conditions if necessary. With a 500 step/rev. stepping motor the resolution is 1.27 μm per step. We presently use this assembly in a remote location for the precise positioning of a beam sensing monitor. 2 refs., 3 figs

  17. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    Directory of Open Access Journals (Sweden)

    Ruzairi Abdul Rahim

    2012-09-01

    Full Text Available This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA. The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments and a nominal frequency range (0–80 Hz, with 10 Hz per step increments. The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

  18. Evaluation of the Keeler Pulsair non-contact tonometer.

    Science.gov (United States)

    Sponsel, W E; Kaufman, P L; Strinden, T I; DePaul, K L; Bowes, H N; Olander, K W; Barnebey, H S

    1989-10-01

    The recently-introduced Pulsair non-contact tonometer (Keeler Instruments, Inc, Broomall, PA) was evaluated against the Goldmann applanation tonometer in cannulated post mortem human eyes, and in living subjects at three clinical centers. Statistical analysis of the findings revealed strong linear relationships between Goldmann or manometric and Pulsair intraocular pressure readings, with correlation coefficients ranging from 0.79 to 0.97. However, with the Pulsair reading as the dependent variable, the slope of the relationship in each case was significantly less than 1.0 (range 0.65 to 0.83), while the intercept was positive (range 1.31 to 2.33 mmHg). Thus, the Pulsair tended to read low at intraocular pressure above the normal range. Conversion factors and a calibration table allowing intraocular pressure estimates more comparable to Goldmann tonometry using the current (J-series) Pulsair are provided herein. A calibration algorithm could be integrated into the circuitry of future production models of the Pulsair instrument.

  19. Shuffle motor: a high force, high precision linear electrostatic stepper motor

    NARCIS (Netherlands)

    Tas, Niels Roelof; Wissink, Jeroen; Sander, A.F.M.; Sander, Louis; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt

    1997-01-01

    The shuffle motor is a electrostatic stepper motor that employs a mechanical transformation to obtain high forces and small steps. A model has been made to calculate the driving voltage, step size and maximum load to pull as well as the optimal geometry. Tests results are an effective step size of

  20. Design optimization of a linear permanent magnet synchronous motor for extra low force pulsations

    International Nuclear Information System (INIS)

    Isfahani, Aarsh Hassanpour; Vaez-Zadeh, Sadegh

    2007-01-01

    Air cored linear permanent magnet synchronous motors have essentially low force pulsations due to the lack of the primary iron core and teeth. However, a motor design with much lower force pulsations is required for many precise positioning systems, as in fabrication of microelectronic chips. This paper presents the design optimization of an air cored linear permanent magnet synchronous motor with extra low force pulsations for such applications. In order to achieve the goal, an analytical layer model of the machine is developed. A very effective objective function regarding force pulsations is then proposed; while the selected motor dimensions are regarded as the design variables. A genetic algorithm is used to find the optimal motor dimensions. This results in a substantial ninety percent reduction in the force pulsations. The design optimization is verified by a finite element method

  1. Drive of a rail locomotive using linear motors. Antrieb eines schienengebundenen Triebfahrzeuges mit Hilfe von Linearmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Kagischke, W; Steffen, U

    1977-12-08

    The purpose of the invention is to avoid the disadvantages of asynchronous linear motors, for example for need for reactive current for excitation, where driving on a normal section and driving on a branch line should be possible without losing the saving in weight on the inductor. According to the invention, the common inductor on a synchronous linear motor consists of 2 parallel packets of laminations surrounded by DC excitation windings and the secondary systems consists of unwound and spaced magnetic sections covering the two packets of laminations on the normal section. In the direction of thrust, their length extends nearly over the pole pitch of the multi-phase AC winding. According to the invetnion, this drive therefore consists of a synchronous linear motor combined into a double motor, with an external, rail shaped fixed secondary system, which has a multi-phase AC winding opposite it.

  2. The non-contact tonometer. Its value and limitations.

    Science.gov (United States)

    Shields, M B

    1980-01-01

    A review of the literature and a comparative study against Goldmann applanation tonometers suggest that the non-contact tonometer is reliable for measuring intraocular pressures within the normal range. In addition, the non-contact tonometer eliminates the need for corneal contact and topical anesthesia, thereby avoiding the potential problems of corneal abrasion, spread of infection, and drug reactions. The instrument can be used reliably by paramedical personnel and has particular value in mass screening and possibly in studies of topical antiglaucoma drugs. The non-contact tonometer is less reliable in patients with elevated intraocular pressure, since comparative studies against the Goldmann applanation tonometers have shown poorer correlations in the higher pressure ranges. The instrument is also limited by an abnormal cornea or poor fixation, which may interfere with accurate pressure measurements. Furthermore, the non-contact tonometer is less portable than many tonometers and more expensive than most.

  3. Inductive Non-Contact Position Sensor

    Science.gov (United States)

    Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

    2010-01-01

    Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and

  4. [Evaluation of accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer].

    Science.gov (United States)

    Chen, X; Peng, D; Zhou, W; Zhong, Y

    1995-06-01

    To evaluate the accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer. 58 patients' (113 eyes) intraocular pressure were measured by Keeler, non-contact tonometer and R 900 Goldmann applanation tonometer and the results of measurement of intraocular pressure by the two kinds of tonometers were compared. The mean intraocular pressure measured by non-contact is 16.31 +/- 5.59 mmHg and 17.49 +/- 6.13 mmHg (1 mmHg = 0.1333 kPa) by Goldmann applanation tonometer, respectively. There was no statistical significance to be found (P > 0.05) between the two methods. By linear correlation and regression analysis, a positive correlation was found between the two methods (r = 0.8942, b = 0.8154). The handheld non-contact tonometer has the same accuracy and reliability of measurement of intraocular pressure comparing with Goldmann applanation tonometer, and it can be used in glaucoma clinic and screening.

  5. Computation of magnetic field in DC brushless linear motors built with NdFeB magnets

    International Nuclear Information System (INIS)

    Basak, A.; Shirkoohi, G.H.

    1990-01-01

    A software package based on finite element technique has been used to compute three-dimensional magnetic fields and static forces developed in brushless d.c. linear motors. As the field flux-source two different types of permanent magnets, one of them being the high energy neodymium- iron-boron type, has been used in computer models. Motors with the same specifications as the computer models were built and experimental results obtained from them are compared with the computed results

  6. Dynamic diagnostics of moving ferromagnetic material with the linear induction motor

    OpenAIRE

    Szewczyk Krzysztof; Walasek Tomasz

    2017-01-01

    The paper presents the application of a three-phase induction motor as a sensor measuring the force of the electromagnetic field connection between the engine and produced sheet steel. The force interaction between the engine and the manufactured sheet metal treated as a treadmill for a linear motor may be an indicator of damage to the material. Detection of places where the sheet does not meet the quality requirements may be very useful in the production process. FEM calculations were perfor...

  7. Efficiency Improvement of a High Dynamic BLDC Linear Motor by Multiphase Control

    OpenAIRE

    Lemmens, Joris; Vanvlasselaer, Kris; Mulier, Kristof; Goossens, Stijn; Symens, Wim; Driesen, Johan

    2013-01-01

    This paper proposes a multiphase control strategy for a high dynamic brushless DC linear motor as an alternative for conventional three-phase field-oriented control. Analysis of the magnetic field waveforms shows that three-phase control is not optimal for the 6-slot 7-pole motor topology. Therefore, a multiphase control strategy is elaborated which injects currents proportional to the electromotive force into each of the nine stator coil groups. This results in a maximal alignment force ...

  8. Linear switched reluctance motor control with PIC18F452 microcontroller

    OpenAIRE

    DURSUN, Mahir; KOÇ, Fatmagül

    2014-01-01

    This paper presents the simulation, control, and experimental results of the velocity of a double-sided, 6/4-poled, 3-phased, 8 A, 24 V, 250 W, and 250 N pull force linear switched reluctance motor (LSRM). In the simulation and experimental study, the reference velocity is constant depending on the position and time. The velocity versus the position of the translator was controlled with fuzzy logic control (FLC) and proportional-integral (PI) control techniques. The motor was control...

  9. A novel tubular linear motor equipped with radially anisotropic NdFeB ring magnets

    International Nuclear Information System (INIS)

    Hor, P.J.

    1998-01-01

    The paper describes the design synthesis and optimisation of a novel tubular linear motor employing radially magnetised anisotropic ring magnets. Design issues, related to optimising the dimensions for maximum acceleration capability, minimum cogging force and low harmonic distortion in the emf waveform, are discussed. The influence of inhomogeneities in the magnets on the performance of a prototype motor is discussed, and its dynamic performance is validated experimentally against a typical target specification for automated high-speed manufacturing applications. (orig.)

  10. The dynamic response of a linear brushless D.C. motor

    Energy Technology Data Exchange (ETDEWEB)

    Moghani, J.S.; Eastham, J.F. [Univ. of Bath (United Kingdom). School of Electrical and Electronic Engineering

    1995-12-31

    The paper describes the use of the Matlab Analogue Simulation Toolbox SIMULINK for the closed loop dynamic modeling of a linear brushless dc motor which is supplied from a delta-modulated inverter. The work is validated by experimental results taken from a large test rig. Linear version of all rotating machines are possible; a rotating machine can be notionally cut along a radial plane and unrolled to yield a linear version. The most popular form of linear machine, as judged by the quantities that have been produced is the linear induction motor. This has the advantage of first an inexpensive secondary that is often a simple iron backed conducting plate, and secondly the possibility of simple voltage control. The linear brushless synchronous motor is potentially more expensive to produce than its induction counterpart because of the permanent magnets which provide the excitation mmf and the necessity of an inverter supply. However the machine has a power factor efficiency product which can be double that of an induction motor together with about twice the tractive force per pole area.

  11. A U-shaped linear ultrasonic motor using longitudinal vibration transducers with double feet.

    Science.gov (United States)

    Liu, Yingxiang; Liu, Junkao; Chen, Weishan; Shi, Shengjun

    2012-05-01

    A U-shaped linear ultrasonic motor using longitudinal vibration transducers with double feet was proposed in this paper. The proposed motor contains a horizontal transducer and two vertical transducers. The horizontal transducer includes two exponential shape horns located at the leading ends, and each vertical transducer contains one exponential shape horn. The horns of the horizontal transducer and the vertical transducer intersect at the tip ends where the driving feet are located. Longitudinal vibrations are superimposed in the motor and generate elliptical motions at the driving feet. The two vibration modes of the motor are discussed, and the motion trajectories of driving feet are deduced. By adjusting the structural parameters, the resonance frequencies of two vibration modes were degenerated. A prototype motor was fabricated and measured. Typical output of the prototype is no-load speed of 854 mm/s and maximum thrust force of 40 N at a voltage of 200 V(rms).

  12. PERFORMANCE OPTIMIZATION OF LINEAR INDUCTION MOTOR BY EDDY CURRENT AND FLUX DENSITY DISTRIBUTION ANALYSIS

    Directory of Open Access Journals (Sweden)

    M. S. MANNA

    2011-12-01

    Full Text Available The development of electromagnetic devices as machines, transformers, heating devices confronts the engineers with several problems. For the design of an optimized geometry and the prediction of the operational behaviour an accurate knowledge of the dependencies of the field quantities inside the magnetic circuits is necessary. This paper provides the eddy current and core flux density distribution analysis in linear induction motor. Magnetic flux in the air gap of the Linear Induction Motor (LIM is reduced to various losses such as end effects, fringes, effect, skin effects etc. The finite element based software package COMSOL Multiphysics Inc. USA is used to get the reliable and accurate computational results for optimization the performance of Linear Induction Motor (LIM. The geometrical characteristics of LIM are varied to find the optimal point of thrust and minimum flux leakage during static and dynamic conditions.

  13. Numerical studies on the force characteristic of superconducting linear synchronous motor with HTS bulk magnet

    Science.gov (United States)

    Tang, Junjie; Li, Jing; Li, Xiang; Han, Le

    2018-03-01

    High temperature superconductor (HTS) bulks have significant potential use in linear motor application act as quasi-permanent magnet to replace traditional magnets. Force characteristic between HTS bulk magnet and traveling magnetic field was investigated with numerical simulation and experimental measurement in this paper. Influences of bulk height and number on the force characteristic were studied by the finite element model considering the nonlinear E-J relationship. Study was also made on addition of a back iron plate to the bulk magnet. Besides, force characteristic of bulk was compared with the permanent magnet results. The small initial decrease of the thrust could be explained by inside superconducting current redistribution. It was found that efficiency of linear motor did not increase by adding more bulk magnets. The bulk magnet will be remagnetized instead of erasing trapped field with the increase of the traveling magnetic field strength. The conclusions are helpful in prediction and design the linear motor with HTS bulk magnet.

  14. Force Profiles of a Linear Switched Reluctance Motor Having Special Pole Face Shapes

    Directory of Open Access Journals (Sweden)

    CHADRESEKAR, V.

    2010-11-01

    Full Text Available In this paper, the results of a finite element analysis are carried out on an new stator geometry of a three phase longitudinal flux Linear Switched Reluctance Motor (LSRM. In the new geometry, pole shoes are affixed to the stator poles. Static and dynamic characteristics for the proposed structure have been highlighted. Motor performance for variable load conditions is discussed. Frequency spectrum analyses of force profile using the fast Fourier transform (FFT are described to predict the vibration frequencies. The 2-Dimensional (2-D finite element analysis (FEA and the experimental results of this paper prove that LSRMs are one of the strong candidates for linear propulsion drives.

  15. Apparatus and method to pulverize rock using a superconducting electromagnetic linear motor

    Science.gov (United States)

    Ignatiev, Alex (Inventor)

    2009-01-01

    A rock pulverizer device based on a superconducting linear motor. The superconducting electromagnetic rock pulverizer accelerates a projectile via a superconducting linear motor and directs the projectile at high speed toward a rock structure that is to be pulverized by collision of the speeding projectile with the rock structure. The rock pulverizer is comprised of a trapped field superconducting secondary magnet mounted on a movable car following a track, a wire wound series of primary magnets mounted on the track, and the complete magnet/track system mounted on a vehicle used for movement of the pulverizer through a mine as well as for momentum transfer during launch of the rock breaking projectile.

  16. Investigation and Calculation of Magnetic Field in Tubular Linear Reluctance Motor Using FEM

    Directory of Open Access Journals (Sweden)

    MOSALLANEJAD, A.

    2010-11-01

    Full Text Available In this paper the magnetic flux density of tubular linear reluctance motor (TLRM in open type magnetic circuit is studied. Also, all magnetic flux density calculation methods in winding of tubular linear reluctance motor are described. The effect of structure parameters on magnetic flux density is also discussed. Electromagnetic finite-element analysis is used for simulation of magnetic field, and simulation results of the magnetic field analysis with DC voltage excitation are compared with results obtained from calculation methods. The comparison yields a good agreement.

  17. International program on linear electric motors. CIGGT report No. 92-1

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, G.E.; Eastham, A.R.; Parker, J.H.

    1992-12-31

    The International Program for Linear Electric Motors (LEM) was begun in April 1989 to communicate and coordinate activities with centers of expertise in Germany, Canada, and Japan; to provide for the assessment and support of the planning of technological developments and for dissemination of information to researchers, service operators, and policy makers; and to ensure that full advantage can be taken if opportunities for technology transfer occur. This report documents the work done under the program, including standardizing linear induction motor (LIM) design characteristics; test procedures and measurement methods; rating; database for design data; criteria for evaluation of designs; computer programs for modelling performance; and a design study for an agreed application.

  18. Modeling and analysis of mover gaps in tubular moving-magnet linear oscillating motors

    Directory of Open Access Journals (Sweden)

    Xuesong LUO

    2018-05-01

    Full Text Available A tubular moving-magnet linear oscillating motor (TMMLOM has merits of high efficiency and excellent dynamic capability. To enhance the thrust performance, quasi-Halbach permanent magnet (PM arrays are arranged on its mover in the application of a linear electro-hydrostatic actuator in more electric aircraft. The arrays are assembled by several individual segments, which lead to gaps between them inevitably. To investigate the effects of the gaps on the radial magnetic flux density and the machine thrust in this paper, an analytical model is built considering both axial and radial gaps. The model is validated by finite element simulations and experimental results. Distributions of the magnetic flux are described in condition of different sizes of radial and axial gaps. Besides, the output force is also discussed in normal and end windings. Finally, the model has demonstrated that both kinds of gaps have a negative effect on the thrust, and the linear motor is more sensitive to radial ones. Keywords: Air-gap flux density, Linear motor, Mover gaps, Quasi-Halbach array, Thrust output, Tubular moving-magnet linear oscillating motor (TMMLOM

  19. Force prediction in permanent magnet flat linear motors (abstract)

    International Nuclear Information System (INIS)

    Eastham, J.F.; Akmese, R.

    1991-01-01

    The advent of neodymium iron boron rare-earth permanent magnet material has afforded the opportunity to construct linear machines of high force to weight ratio. The paper describes the design and construction of an axial flux machine and rotating drum test rig. The machine occupies an arc of 45 degree on a drum 1.22 m in diameter. The excitation is provided by blocks of NdFeB material which are skewed in order to minimize the force variations due to slotting. The stator carries a three-phase short-chorded double-layer winding of four poles. The machine is supplied by a PWM inverter the fundamental component of which is phase locked to the rotor position so that a ''dc brushless'' drive system is produced. Electromagnetic forces including ripple forces are measured at supply frequencies up to 100 Hz. They are compared with finite-element analysis which calculates the force variation over the time period. The paper then considers some of the causes of ripple torque. In particular, the force production due solely to the permanent magnet excitation is considered. This has two important components each acting along the line of motion of the machine, one is due to slotting and the other is due to the finite length of the primary. In the practical machine the excitation poles are skewed to minimize the slotting force and the effectiveness of this is confirmed by both results from the experiments and the finite-element analysis. The end effect force is shown to have a space period of twice that of the excitation. The amplitude of this force and its period are again confirmed by practical results

  20. Generating linear regression model to predict motor functions by use of laser range finder during TUG.

    Science.gov (United States)

    Adachi, Daiki; Nishiguchi, Shu; Fukutani, Naoto; Hotta, Takayuki; Tashiro, Yuto; Morino, Saori; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Yorozu, Ayanori; Takahashi, Masaki; Aoyama, Tomoki

    2017-05-01

    The purpose of this study was to investigate which spatial and temporal parameters of the Timed Up and Go (TUG) test are associated with motor function in elderly individuals. This study included 99 community-dwelling women aged 72.9 ± 6.3 years. Step length, step width, single support time, variability of the aforementioned parameters, gait velocity, cadence, reaction time from starting signal to first step, and minimum distance between the foot and a marker placed to 3 in front of the chair were measured using our analysis system. The 10-m walk test, five times sit-to-stand (FTSTS) test, and one-leg standing (OLS) test were used to assess motor function. Stepwise multivariate linear regression analysis was used to determine which TUG test parameters were associated with each motor function test. Finally, we calculated a predictive model for each motor function test using each regression coefficient. In stepwise linear regression analysis, step length and cadence were significantly associated with the 10-m walk test, FTSTS and OLS test. Reaction time was associated with the FTSTS test, and step width was associated with the OLS test. Each predictive model showed a strong correlation with the 10-m walk test and OLS test (P motor function test. Moreover, the TUG test time regarded as the lower extremity function and mobility has strong predictive ability in each motor function test. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  1. Linear Motor Motion Control Experiment System Design Based on LabVIEW

    Directory of Open Access Journals (Sweden)

    Cuixian He

    2018-01-01

    Full Text Available In order to meet the needs of experimental training of electrical information industry, a linear motor motion experiment system based on LabVIEW was developed. This system is based on the STM32F103ZET6 system processor controller, a state signal when the motor moves through the grating encoder feedback controller to form a closed loop, through the RS232 serial port communication with the host computer, the host computer is designed in the LabVIEW interactive environment monitoring software. Combined with the modular design concept proposed overall program, given the detailed hardware circuit, targeted for the software function design, to achieve man-machine interface. The system control of high accuracy, good stability, meet the training requirements for laboratory equipment, but also as a reference embodiment of the linear motor monitoring system.

  2. A speed estimation unit for induction motors based on adaptive linear combiner

    International Nuclear Information System (INIS)

    Marei, Mostafa I.; Shaaban, Mostafa F.; El-Sattar, Ahmed A.

    2009-01-01

    This paper presents a new induction motor speed estimation technique, which can estimate the rotor resistance as well, from the measured voltage and current signals. Moreover, the paper utilizes a novel adaptive linear combiner (ADALINE) structure for speed and rotor resistance estimations. This structure can deal with the multi-output systems and it is called MO-ADALINE. The model of the induction motor is arranged in a linear form, in the stationary reference frame, to cope with the proposed speed estimator. There are many advantages of the proposed unit such as wide speed range capability, immunity against harmonics of measured waveforms, and precise estimation of the speed and the rotor resistance at different dynamic changes. Different types of induction motor drive systems are used to evaluate the dynamic performance and to examine the accuracy of the proposed unit for speed and rotor resistance estimation.

  3. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Wan-Tsun Tseng

    2013-01-01

    Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

  4. Application of static var compensator on large synchronous motors based on linear optimization control design

    International Nuclear Information System (INIS)

    Soltani, J.; Fath Abadi, A.M.

    2003-01-01

    This paper describes the application of static var compensators, on an electrical distribution network containing two large synchronous motors, one of which is excited via a three-phase thyristor bridge rectifier. The second machine is excited via a diode bridge rectifier. Based on linear optimization control, the measurable feedback signals are applied to the control system loops of static var compensators and the excitation control loop of the first synchronous motor. The phase equations method was used to develop a computer program to model the distribution network. Computer results were obtained to demonstrate the system performance for some abnormal modes of operation. These results show that employing static var compensators based on the linear optimization control design for electrical distribution networks containing large synchronous motors is beneficial and may be considered a first stage of the system design

  5. Thermal analysis of linear pulse motor for SMART control element drive mechanism

    International Nuclear Information System (INIS)

    Hur, H.; Kim, J. H.; Kim, J. I.; Jang, K. C.; Kang, D. H.

    1999-01-01

    It is important that the temperature of the motor windings be maintained within the allowable limit of the insulation, since the linear pulse motor of CEDM is always supplied with current during the reactor operation. In this study three motor windings were fabricated with three different diameters of coil wires, and the temperatures inside the windings were measured with different current values. As the insulation of the windings is composed of teflon, glass fiber, and air, it is not an easy task to determine experimentally the thermal properties of the complex insulation. In this study, the thermal properties of the insulation were obtained by comparing the results of finite element thermal analyses and those of experiment. The thermal properties obtained here will be used as input for the optimization analysis of the motor

  6. Speed Sensorless mixed sensitivity linear parameter variant H_inf control of the induction motor

    NARCIS (Netherlands)

    Toth, R.; Fodor, D.

    2004-01-01

    The paper shows the design of a robust control structure for the speed sensorless vector control of the IM, based on the mixed sensitivity (MS) linear parameter variant (LPV) H8 control theory. The controller makes possible the direct control of the flux and speed of the motor with torque adaptation

  7. Spectral element model for 2-D electrostatic fields in a linear synchronous motor

    NARCIS (Netherlands)

    van Beek, T.A.; Curti, M.; Jansen, J.W.; Gysen, B.L.J.; Paulides, J.J.H.; Lomonova, E.A.

    2017-01-01

    This paper presents a fast and accurate 2-D spectral element model for analyzing electric field distributions in linear synchronous motors. The electric field distribution is derived using the electric scalar potential for static cases. The spatial potential and electric field distributions obtained

  8. Torque decomposition and control in an iron core linear permanent magnet motor.

    NARCIS (Netherlands)

    Overboom, T.T.; Smeets, J.P.C.; Stassen, J.M.; Jansen, J.W.; Lomonova, E.

    2012-01-01

    Abstract—This paper concerns the decomposition and control of the torque produced by an iron core linear permanent magnet motor. The proposed method is based on the dq0-decomposition of the three-phase currents using Park’s transformation. The torque is decomposed into a reluctance component and two

  9. Power-optimal force decoupling in a hybrid linear reluctance motor

    NARCIS (Netherlands)

    Overboom, T.T.; Smeets, J.P.C.; Jansen, J.W.; Lomonova, E.A.; Mavrudieva, D.

    2015-01-01

    This paper concerns the power-optimal decoupling of the propulsion and normal force created by a hybrid linear reluctance motor. The intrinsic limitations to the decoupling is addressed by the visualizing each force component with a quadric surface in the Euclidean space which is spanned by the

  10. Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays

    OpenAIRE

    Nakaiwa, K; Yamada, A; Tashiro, K; Wakiwaka, H

    2009-01-01

    From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

  11. Overview of analytical models for the design of linear and planar motors

    NARCIS (Netherlands)

    Jansen, J.W.; Smeets, J.P.C.; Overboom, T.T.; Rovers, J.M.M.; Lomonova, E.A.

    2014-01-01

    In this paper, an overview of analytical techniques for the modeling of linear and planar permanent-magnet motors is given. These models can be used complementary to finite element analyses for fast evaluations of topologies, but they are indispensable for the design of magnetically levitated planar

  12. Continuous control systems for non-contact ECG

    Science.gov (United States)

    Kodkin, Vladimir L.; Yakovleva, Galina V.; Smirnov, Alexey S.

    2017-03-01

    South Ural State University is still conducting the research work dedicated to innovations in biomedicine. Development of system for continuous control and diagnosis of the functional state in large groups of people is based on studies of non-contact ECG recording reported by the authors at the SPIE conference in 2016. The next stage of studies has been performed this year.

  13. Non-contact finger vein acquisition system using NIR laser

    Science.gov (United States)

    Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

    2009-02-01

    Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

  14. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  15. Non-contact remote monitoring technique of reactor structural elements

    International Nuclear Information System (INIS)

    Inoue, Hideo; Mori, Kazuo; Ozawa, Norimitsu; Akedo, Jun; Seimiya, Koichi; Chikamori, Kunio; Umezawa, Akihiko

    1998-01-01

    This study aims at development of technique to measure and estimate, at high precision, fine machining scratch, crack and so on formed on grinding tubular elements, especially inner faces of small diameter tube at an optical mirror grade, and at establishment of estimation technique on reliability and soundness of the tubular elements. In this fiscal year, on optical type non-contact monitoring technique, investigations on optical illumination condition and holding accuracy required for the non-contact holding mechanism were conducted by using a sensor head trially produced in 1995 fiscal year. And, in order to realize a high precision non-contact holding in a tube of optical detection system to upgrade static holding properties (holding stiffness, holding attitude, and so on) of pneumatic type inner tube non-contact holding mechanism, realization of increase in supplying air pressure and experiments using a holding mechanism to increase pore numbers of air injecting nozzle were conducted. And, on materials surface technique, effect of difference in pre-machining method (cutting and bright annealing) at inner face of small diameter stainless tube on their smooth machining property was examined. (G.K.)

  16. Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry

    International Nuclear Information System (INIS)

    Zuckermann, Martin J; Forde, Nancy R; Angstmann, Christopher N; Schmitt, Regina; Linke, Heiner; Blab, Gerhard A; Bromley, Elizabeth HC; Curmi, Paul MG

    2015-01-01

    The stepping direction of linear molecular motors is usually defined by a spatial asymmetry of the motor, its track, or both. Here we present a model for a molecular walker that undergoes biased directional motion along a symmetric track in the presence of a temporally symmetric chemical cycle. Instead of using asymmetry, directionality is achieved by persistence. At small load force the walker can take on average thousands of steps in a given direction until it stochastically reverses direction. We discuss a specific experimental implementation of a synthetic motor based on this design and find, using Langevin and Monte Carlo simulations, that a realistic walker can work against load forces on the order of picoNewtons with an efficiency of ∼18%, comparable to that of kinesin. In principle, the walker can be turned into a permanent motor by externally monitoring the walker’s momentary direction of motion, and using feedback to adjust the direction of a load force. We calculate the thermodynamic cost of using feedback to enhance motor performance in terms of the Shannon entropy, and find that it reduces the efficiency of a realistic motor only marginally. We discuss the implications for natural protein motor performance in the context of the strong performance of this design based only on a thermal ratchet. (paper)

  17. Dynamic modeling and characteristics analysis of a modal-independent linear ultrasonic motor.

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; Zhou, Shengli; Lv, Qibao; Liu, Zhen

    2016-12-01

    In this paper, an integrated model is developed to analyze the fundamental characteristics of a modal-independent linear ultrasonic motor with double piezoelectric vibrators. The energy method is used to model the dynamics of the two piezoelectric vibrators. The interface forces are coupled into the dynamic equations of the two vibrators and the moving platform, forming a whole machine model of the motor. The behavior of the force transmission of the motor is analyzed via the resulting model to understand the drive mechanism. In particular, the relative contact length is proposed to describe the intermittent contact characteristic between the stator and the mover, and its role in evaluating motor performance is discussed. The relations between the output speed and various inputs to the motor and the start-stop transients of the motor are analyzed by numerical simulations, which are validated by experiments. Furthermore, the dead-zone behavior is predicted and clarified analytically using the proposed model, which is also observed in experiments. These results are useful for designing servo control scheme for the motor. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Dynamic contour tonometry (DCT) versus non-contact tonometry (NCT): a comparison study.

    Science.gov (United States)

    Burvenich, H; Burvenich, E; Vincent, C

    2005-01-01

    In a prospective study we measured the intraocular pressure (IOP) by means of a Non-Contact Tonometer (NCT) and by means of a Pascal Dynamic Contour Tonometer (DCT), and the Central Corneal Thickness (CCT) by means of a contact pachymeter in 294 emmetropic or ametropic eyes. There is a linear relation between NCT and CCT. This linear relation doesn't exist between DCT and CCT. The same measurements were done before and 6 weeks after a Lasik intervention in 58 myopic eyes. Lasik intervention influences NCT but doesn't influence DCT.

  19. A clinical evaluation of the non-contact tonometer.

    Science.gov (United States)

    Wittenberg, S

    1977-02-01

    Paired non-contact tonometer readings were taken on patients at the Boston City Hospital Eye Clinic before and after routine vision care that included Goldmann tonometry. The variability of NCT readings was determined and comparisons made between readings obtained with the NCT and Goldmann instruments. The regression equation relating the pre-Goldmann NCT findings (N1), to the Goldmann (G), was N1 = 1.01G + 1.97; and the equation relating the post-Goldmann NCT findings (N2), to the Goldman was N2 = .94G + 1.70. The N1 mean was 2.06 mm. higher than the mean G, while the N2 mean was .58 mm. higher than the mean G. The correlation coefficients and standard deviation of the differences for the two comparisons were, .88, 3.91, and .93, 3.07, respectively. The Goldmann findings therefore were seen to agree more closely with the NCT findings taken after them. The linear regression and correlation coefficients between the NCT and the Goldmann were generally in good agreement with those of prior studies, although the standard deviations of the differences between findings were larger in this study. This result is not surprising since no attempt was made to train Goldmann operators to criterion or to limit variability induced by differing observer criteria or by the use of only one Goldmann operator. The operators of the Goldmann tonometer had varying degrees of training as residents in ophthalmology. Interestingly, the agreement between pre-Goldmann NCT and post-Goldmann NCT findings was not good. This suggested that the taking of the Goldmann findings themselves may have had a significant effect on the tonometric readings and that the considerable time that frequently took place between the two sets of NCT readings could have affected the value. The standard deviation of the differences between pre- and post-Goldmann readings on the same patient was 3.27 as compared to that for paired readings which was 2.28. The data also showed a much better agreement between the NCT and

  20. Current error vector based prediction control of the section winding permanent magnet linear synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Hong Junjie, E-mail: hongjjie@mail.sysu.edu.cn [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China); Li Liyi, E-mail: liliyi@hit.edu.cn [Dept. Electrical Engineering, Harbin Institute of Technology, Harbin 150000 (China); Zong Zhijian; Liu Zhongtu [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China)

    2011-10-15

    Highlights: {yields} The structure of the permanent magnet linear synchronous motor (SW-PMLSM) is new. {yields} A new current control method CEVPC is employed in this motor. {yields} The sectional power supply method is different to the others and effective. {yields} The performance gets worse with voltage and current limitations. - Abstract: To include features such as greater thrust density, higher efficiency without reducing the thrust stability, this paper proposes a section winding permanent magnet linear synchronous motor (SW-PMLSM), whose iron core is continuous, whereas winding is divided. The discrete system model of the motor is derived. With the definition of the current error vector and selection of the value function, the theory of the current error vector based prediction control (CEVPC) for the motor currents is explained clearly. According to the winding section feature, the motion region of the mover is divided into five zones, in which the implementation of the current predictive control method is proposed. Finally, the experimental platform is constructed and experiments are carried out. The results show: the current control effect has good dynamic response, and the thrust on the mover remains constant basically.

  1. Unmasking the linear behaviour of slow motor adaptation to prolonged convergence.

    Science.gov (United States)

    Erkelens, Ian M; Thompson, Benjamin; Bobier, William R

    2016-06-01

    Adaptation to changing environmental demands is central to maintaining optimal motor system function. Current theories suggest that adaptation in both the skeletal-motor and oculomotor systems involves a combination of fast (reflexive) and slow (recalibration) mechanisms. Here we used the oculomotor vergence system as a model to investigate the mechanisms underlying slow motor adaptation. Unlike reaching with the upper limbs, vergence is less susceptible to changes in cognitive strategy that can affect the behaviour of motor adaptation. We tested the hypothesis that mechanisms of slow motor adaptation reflect early neural processing by assessing the linearity of adaptive responses over a large range of stimuli. Using varied disparity stimuli in conflict with accommodation, the slow adaptation of tonic vergence was found to exhibit a linear response whereby the rate (R(2)  = 0.85, P < 0.0001) and amplitude (R(2)  = 0.65, P < 0.0001) of the adaptive effects increased proportionally with stimulus amplitude. These results suggest that this slow adaptive mechanism is an early neural process, implying a fundamental physiological nature that is potentially dominated by subcortical and cerebellar substrates. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  2. Design and testing of a coaxial linear magnetic spring with integral linear motor. [for spacecraft energy storage

    Science.gov (United States)

    Patt, P. J.

    1985-01-01

    The design of a coaxial linear magnetic spring which incorporates a linear motor to control axial motion and overcome system damping is presented, and the results of static and dynamic tests are reported. The system has nominal stiffness 25,000 N/m and is designed to oscillate a 900-g component over a 4.6-mm stroke in a Stirling-cycle cryogenic refrigerator being developed for long-service (5-10-yr) space applications (Stolfi et al., 1983). Mosaics of 10 radially magnetized high-coercivity SmCO5 segments enclosed in Ti cans are employed, and the device is found to have quality factor 70-100, corresponding to energy-storage efficiency 91-94 percent. Drawings, diagrams, and graphs are provided.

  3. A superconducting linear motor drive for a positive displacement bellows pump for use in the g-2 cryogenics system

    International Nuclear Information System (INIS)

    Green, M.A.

    1994-10-01

    Forced two-phase cooling of indirectly cooled magnets requires circulation of liquid helium through the magnet cooling channel. A bellows helium pump is one possible way of providing helium flow to a magnet cooling system. Since the bellows type of helium pump is immersed in liquid helium, a superconducting linear motor drive appears to be an attractive option. This report describes a linear motor drive that employs oriented permanent magnet materials such as samarium-cobalt as the stator magnet system and a superconducting loud speaker voice coil type of drive as the armature of the linear motor. This report examines drive motor requirements for a helium pump

  4. Universal Linear Motor Driven Leg Press Dynamometer and Concept of Serial Stretch Loading.

    Science.gov (United States)

    Hamar, Dušan

    2015-08-24

    Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase) or acceleration (in eccentric phase). Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients.

  5. A study on the integration of contactless energy transfer in the end teeth of a PM synchronous linear motor

    NARCIS (Netherlands)

    Krop, D.C.J.; Lomonova, E.A.; Jansen, J.W.; Paulides, J.J.H.

    2009-01-01

    Linear motors find their utilization in an increasing number of industrial applications. Permanent magnet linear synchronous motors (PMLSMs) are favorable in many applications due to their servo characteristics, robustness, and high force density. The major disadvantage of moving coil type PMLSMs is

  6. Application of an imperialist competitive algorithm to the design of a linear induction motor

    International Nuclear Information System (INIS)

    Lucas, Caro; Nasiri-Gheidari, Zahra; Tootoonchian, Farid

    2010-01-01

    In this paper a novel optimization algorithm based on imperialist competitive algorithm (ICA) is used for the design of a low speed single sided linear induction motor (LIM). This type of motors is used increasingly in industrial process specially in transportation systems. In these applications having high efficiency with high power factor is very important. So in this paper the objective function of design is presented considering both efficiency and power factor. Finally the results of ICA are compared with the ones of genetic algorithm and conventional design. Comparison shows the success of ICA for design of LIMs.

  7. Development of sealed nickel-cadmium battery for linear motor car (Maglev). Linear motor car yo Ni-Cd denchi no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kono, K; Yoshimura, H; Yufu, H [Yuasa Corp., Osaka (Japan)

    1993-10-29

    Development was made of a linear motor car use battery which is strong in repetition of quick charging/discharging and characterized as follows: Its volumetric energy density is 42Wh/kg which is 1.3 times as high as the conventional one. It excels in high efficiency charging/discharging characteristics. High tension steel sheet is used for it, which is incombustible. To lighten the weight, paste type electrodes and high yield point materials were used for the positive and negative electrodes, and jar materials, respectively. To heighten the charging/discharging characteristics, used were electrodes heightened in current collecting effect. To lengthening the life, unwoven nylon cloth was used as a separator. Also to heighten the thermal discharge characteristics, the electrodes were made metallic with a fitting of cooling fins. The battery characteristics as tested gave the following result: At a capacity ratio of 100%, the discharging factor cleared its target value of development also with a high discharging voltage. The charging/discharging characteristics hardly fall in the high temperature region. The charging characteristics include quick charging made possible. As a result of cyclic simulation presuming the linear motor car, the fall in capacity per cycle was as good as 1.5%. 11 figs., 2 tabs.

  8. Inertial piezoelectric linear motor driven by a single-phase harmonic wave with automatic clamping mechanism

    Science.gov (United States)

    He, Liangguo; Chu, Yuheng; Hao, Sai; Zhao, Xiaoyong; Dong, Yuge; Wang, Yong

    2018-05-01

    A novel, single-phase, harmonic-driven, inertial piezoelectric linear motor using an automatic clamping mechanism was designed, fabricated, and tested to reduce the sliding friction and simplify the drive mechanism and power supply control of the inertial motor. A piezoelectric bimorph and a flexible hinge were connected in series to form the automatic clamping mechanism. The automatic clamping mechanism was used as the driving and clamping elements. A dynamic simulation by Simulink was performed to prove the feasibility of the motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental setup was built to validate the working principle and evaluate the performance of the motor. The prototype motor outputted a no-load velocity of 3.178 mm/s at a voltage of 220 Vp-p and a maximum traction force of 4.25 N under a preload force of 8 N. The minimum resolution of 1.14 μm was achieved at a driving frequency of 74 Hz, a driving voltage of 50 Vp-p, and a preload force of 0 N.

  9. A rectangle-type linear ultrasonic motor using longitudinal vibration transducers with four driving feet.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

    2013-04-01

    To make full use of the vibrational energy of a longitudinal transducer, a rectangle-type linear ultrasonic motor with four driving feet is proposed in this paper. This new motor consists of four longitudinal vibration transducers which are arranged in a rectangle and form an enclosed construction. Lead zirconate titanate ceramics are embedded into the middle of the transducer and fastened by a wedge-caulking mechanism. Each transducer includes an exponentially shaped horn located on each end. The horns of the vertical transducers intersect at the base of the horizontal transducers' horns; the tip ends of the horizontal transducers' horns are used as the driving feet. Longitudinal vibrations are superimposed in the motor and generate elliptical movements at the tip ends of the horns. The working principle of the proposed motor is analyzed. The resonance frequencies of two working modes are tuned to be close to each other by adjusting the structural parameters. Transient analysis is developed to gain the vibration characteristics of the motor. A prototype motor is fabricated and measured. The vibration test results verify the feasibility of the proposed design. Typical output of the prototype is a no-load speed of 928 mm/s and maximum thrust force of 60 N at a voltage of 200 Vrms.

  10. Development of an ultrasonic linear motor with ultra-positioning capability and four driving feet.

    Science.gov (United States)

    Zhu, Cong; Chu, Xiangcheng; Yuan, Songmei; Zhong, Zuojin; Zhao, Yanqiang; Gao, Shuning

    2016-12-01

    This paper presents a novel linear piezoelectric motor which is suitable for rapid ultra-precision positioning. The finite element analysis (FEA) was applied for optimal design and further analysis, then experiments were conducted to investigate its performance. By changing the input signal, the proposed motor was found capable of working in the fast driving mode as well as in the precision positioning mode. When working in the fast driving mode, the motor acts as an ultrasonic motor with maximum no-load speed up to 181.2mm/s and maximum thrust of 1.7N at 200Vp-p. Also, when working in precision positioning mode, the motor can be regarded as a flexible hinge piezoelectric actuator with arbitrary motion in the range of 8μm. The measurable minimum output displacement was found to be 0.08μm, but theoretically, can be even smaller. More importantly, the motor can be quickly and accurately positioned in a large stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A non-contact time-domain scanning brain imaging system: first in-vivo results

    Science.gov (United States)

    Mazurenka, M.; Di Sieno, L.; Boso, G.; Contini, D.; Pifferi, A.; Dalla Mora, A.; Tosi, A.; Wabnitz, H.; Macdonald, R.

    2013-06-01

    We present results of first in-vivo tests of an optical non-contact scanning imaging system, intended to study oxidative metabolism related processes in biological tissue by means of time-resolved near-infrared spectroscopy. Our method is a novel realization of the short source-detector separation approach and based on a fast-gated single-photon avalanche diode to detect late photons only. The scanning system is built in quasi-confocal configuration and utilizes polarizationsensitive detection. It scans an area of 4×4 cm2, recording images with 32×32 pixels, thus creating a high density of source-detector pairs. To test the system we performed a range of in vivo measurements of hemodynamic changes in several types of biological tissues, i.e. skin (Valsalva maneuver), muscle (venous and arterial occlusions) and brain (motor and cognitive tasks). Task-related changes in hemoglobin concentrations were clearly detected in skin and muscle. The brain activation shows weaker, but yet detectable changes. These changes were localized in pixels near the motor cortex area (C3). However, it was found that even very short hair substantially impairs the measurement. Thus the applicability of the scanner is limited to hairless parts of body. The results of our first in-vivo tests prove the feasibility of non-contact scanning imaging as a first step towards development of a prototype for biological tissue imaging for various medical applications.

  12. Simulation of non-contact tonometer - Ocular response analyzer

    Directory of Open Access Journals (Sweden)

    M. Arsalan Khan

    2016-04-01

    Simultaneous explosion of ophthalmic knowledge and medical instrument, being made in the 19th century, has led to the invention of tonometers of varied designs and principles, and Non-Contact Tonometers (NCTs are among them. Glodmann Applanation Tonometer (GAT is considered the ‘gold standard’ in measuring IOP; however, IOP measurement using GAT is now known to be affected by various factors like corneal thickness, curvature and material properties as demonstrated by Khan [1]. Due to inaccuracies in measuring IOP by GAT, this ‘gold standard’ has been challenged. Therefore, the present research aims to develop a multi-parametric correction equation to determine the True Intraocular Pressure (IOPT using Non-Contact Tonometer and the current article focuses on evaluating the influence of individual parameters on IOP by NCT.

  13. Coupled biomechanical response of the cornea assessed by non-contact tonometry. A simulation study.

    Directory of Open Access Journals (Sweden)

    Miguel Á Ariza-Gracia

    Full Text Available The mechanical response of the cornea subjected to a non-contact air-jet tonometry diagnostic test represents an interplay between its geometry, the corneal material behavior and the loading. The objective is to study this interplay to better understand and interpret the results obtained with a non-contact tonometry test. A patient-specific finite element model of a healthy eye, accounting for the load free configuration, was used. The corneal tissue was modeled as an anisotropic hyperelastic material with two preferential directions. Three different sets of parameters within the human experimental range obtained from inflation tests were considered. The influence of the IOP was studied by considering four pressure levels (10-28 mmHg whereas the influence of corneal thickness was studied by inducing a uniform variation (300-600 microns. A Computer Fluid Dynamics (CFD air-jet simulation determined pressure loading exerted on the anterior corneal surface. The maximum apex displacement showed a linear variation with IOP for all materials examined. On the contrary, the maximum apex displacement followed a cubic relation with corneal thickness. In addition, a significant sensitivity of the apical displacement to the corneal stiffness was also obtained. Explanation to this behavior was found in the fact that the cornea experiences bending when subjected to an air-puff loading, causing the anterior surface to work in compression whereas the posterior surface works in tension. Hence, collagen fibers located at the anterior surface do not contribute to load bearing. Non-contact tonometry devices give useful information that could be misleading since the corneal deformation is the result of the interaction between the mechanical properties, IOP, and geometry. Therefore, a non-contact tonometry test is not sufficient to evaluate their individual contribution and a complete in-vivo characterization would require more than one test to independently determine

  14. Non-contact fluid characterization in containers using ultrasonic waves

    Science.gov (United States)

    Sinha, Dipen N [Los Alamos, NM

    2012-05-15

    Apparatus and method for non-contact (stand-off) ultrasonic determination of certain characteristics of fluids in containers or pipes are described. A combination of swept frequency acoustic interferometry (SFAI), wide-bandwidth, air-coupled acoustic transducers, narrowband frequency data acquisition, and data conversion from the frequency domain to the time domain, if required, permits meaningful information to be extracted from such fluids.

  15. Non-contacting "snubber bearing" for passive magnetic bearing systems

    Science.gov (United States)

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  16. Non-contact tonometry in the postoperative eye.

    OpenAIRE

    Vernon, S A

    1989-01-01

    The Keeler Pulsair non-contact tonometer was compared with the Goldmann applanation tonometer in a series of 48 eyes after operation. A correlation coefficient of 0.92 (p less than 0.001) was found between the two instruments, with the Pulsair having a statistically significant tendency to overread the Goldmann slightly in this situation. The Pulsair was, however, shown to be effective in the identification of postoperative ocular hypertension with a high degree of sensitivity and specificity...

  17. Driving performance of a two-dimensional homopolar linear DC motor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Yamaguchi, M.; Kano, Y. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1998-05-01

    This paper presents a novel two-dimensional homopolar linear de motor (LDM) which can realize two-dimensional (2-D) motion. For position control purposes, two kinds of position detecting methods are proposed. The position in one position is detected by means of a capacitive sensor which makes the output of the sensor partially immune to the variation of the gap between electrodes. The position in the other direction is achieved by exploiting the position dependent property of the driving coil inductance, instead of using an independent sensor. The position control is implemented on the motor and 2-D tracking performance is analyzed. Experiments show that the motor demonstrates satisfactory driving performance, 2-D tracking error being within 5.5% when the angular frequency of reference signal is 3.14 rad./s. 7 refs., 17 figs., 2 tabs.

  18. Innervation zones of fasciculating motor units: observations by a linear electrode array.

    Science.gov (United States)

    Jahanmiri-Nezhad, Faezeh; Barkhaus, Paul E; Rymer, William Z; Zhou, Ping

    2015-01-01

    This study examines the innervation zone (IZ) in the biceps brachii muscle in healthy subjects and those with amyotrophic lateral sclerosis (ALS) using a 20-channel linear electromyogram (EMG) electrode array. Raster plots of individual waveform potentials were studied to estimate the motor unit IZ. While this work mainly focused on fasciculation potentials (FPs), a limited number of motor unit potentials (MUPs) from voluntary activity of 12 healthy and seven ALS subjects were also examined. Abnormal propagation of MUPs and scattered IZs were observed in fasciculating units, compared with voluntarily activated MUPs in healthy and ALS subjects. These findings can be related to muscle fiber reinnervation following motor neuron degeneration in ALS and the different origin sites of FPs compared with voluntary MUPs.

  19. Torque ripple reduction of brushless DC motor based on adaptive input-output feedback linearization.

    Science.gov (United States)

    Shirvani Boroujeni, M; Markadeh, G R Arab; Soltani, J

    2017-09-01

    Torque ripple reduction of Brushless DC Motors (BLDCs) is an interesting subject in variable speed AC drives. In this paper at first, a mathematical expression for torque ripple harmonics is obtained. Then for a non-ideal BLDC motor with known harmonic contents of back-EMF, calculation of desired reference current amplitudes, which are required to eliminate some selected harmonics of torque ripple, are reviewed. In order to inject the reference harmonic currents to the motor windings, an Adaptive Input-Output Feedback Linearization (AIOFBL) control is proposed, which generates the reference voltages for three phases voltage source inverter in stationary reference frame. Experimental results are presented to show the capability and validity of the proposed control method and are compared with the vector control in Multi-Reference Frame (MRF) and Pseudo-Vector Control (P-VC) method results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. High Precision Piezoelectric Linear Motors for Operations at Cryogenic Temperatures and Vacuum

    Science.gov (United States)

    Wong, D.; Carman, G.; Stam, M.; Bar-Cohen, Y.; Sen, A.; Henry, P.; Bearman, G.; Moacanin, J.

    1995-01-01

    The Jet Propulsion Laboratory evaluated the use of an electromechanical device for optically positioning a mirror system during the pre-project phase of the Pluto-Fast-Flyby (PFF) mission. The device under consideration was a piezoelectric driven linear motor functionally dependent upon a time varying electric field which induces displacements ranging from submicrons to millimeters with positioning accuracy within nanometers. Using a control package, the mirror system provides image motion compensation and mosaicking capabilities. While this device offers unique advantages, there were concerns pertaining to its operational capabilities for the PFF mission. The issues include irradiation effects and thermal concerns. A literature study indicated that irradiation effects will not significantly impact the linear motor's operational characteristics. On the other hand, thermal concerns necessitated an in depth study.

  1. Linear magnetic motor/generator. [to generate electric energy using magnetic flux for spacecraft power supply

    Science.gov (United States)

    Studer, P. A. (Inventor)

    1982-01-01

    A linear magnetic motor/generator is disclosed which uses magnetic flux to provide mechanical motion or electrical energy. The linear magnetic motor/generator includes an axially movable actuator mechanism. A permament magnet mechanism defines a first magnetic flux path which passes through a first end portion of the actuator mechanism. Another permament magnet mechanism defines a second magnetic flux path which passes through a second end portion of the actuator mechanism. A drive coil defines a third magnetic flux path passing through a third central portion of the actuator mechanism. A drive coil selectively adds magnetic flux to and subtracts magnetic flux from magnetic flux flowing in the first and second magnetic flux path.

  2. Design and experiments of a linear piezoelectric motor driven by a single mode.

    Science.gov (United States)

    Liu, Zhen; Yao, Zhiyuan; Li, Xiang; Fu, Qianwei

    2016-11-01

    In this contribution, we propose a novel linear piezoelectric motor with a compact stator that is driven by a single mode. The linear piezoelectric motor can realize bidirectional motion by changing the vibration modes of the stator. Finite element analysis is performed to determine the required vibration mode of the stator and obtain the optimal stator structure and dimensions. Furthermore, the trajectories of the driving foot are analyzed with and without consideration of the mechanical contact with the slider. It is shown that the trajectory of the driving foot is an oblique line when disregarding the contact, and the trajectory becomes an oblique ellipse while taking into account the contact. Finally, a prototype of the motor is fabricated based on the results of finite element analysis. The optimization results show that the motor reaches its maximum thrust force of 4.0 kg, maximum thrust-weight ratio of 33.3, maximum unloaded velocity of 385 mm/s under the excitation of Mode-B, and maximum unloaded velocity of 315 mm/s under the excitation of Mode-L.

  3. Evaluation of linear DC motor actuators for control of large space structures

    OpenAIRE

    Ide, Eric Nelson

    1988-01-01

    This thesis examines the use of a linear DC motor as a proof mass actuator for the control of large space structures. A model for the actuator, including the current and force compensation used, is derived. Because of the force compensation, the actuator is unstable when placed on a structure. Relative position feedback is used for actuator stabilization. This method of compensation couples the actuator to the mast in a feedback configuration. Three compensator designs are prop...

  4. Computer-aided design studies of the homopolar linear synchronous motor

    Science.gov (United States)

    Dawson, G. E.; Eastham, A. R.; Ong, R.

    1984-09-01

    The linear induction motor (LIM), as an urban transit drive, can provide good grade-climbing capabilities and propulsion/braking performance that is independent of steel wheel-rail adhesion. In view of its 10-12 mm airgap, the LIM is characterized by a low power factor-efficiency product of order 0.4. A synchronous machine offers high efficiency and controllable power factor. An assessment of the linear homopolar configuration of this machine is presented as an alternative to the LIM. Computer-aided design studies using the finite element technique have been conducted to identify a suitable machine design for urban transit propulsion.

  5. Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

    Directory of Open Access Journals (Sweden)

    Jan Vittek

    2004-01-01

    Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

  6. Electrohydraulic linear actuator with two stepping motors controlled by overshoot-free algorithm

    Science.gov (United States)

    Milecki, Andrzej; Ortmann, Jarosław

    2017-11-01

    The paper describes electrohydraulic spool valves with stepping motors used as electromechanical transducers. A new concept of a proportional valve in which two stepping motors are working differentially is introduced. Such valve changes the fluid flow proportionally to the sum or difference of the motors' steps numbers. The valve design and principle of its operation is described. Theoretical equations and simulation models are proposed for all elements of the drive, i.e., the stepping motor units, hydraulic valve and cylinder. The main features of the valve and drive operation are described; some specific problem areas covering the nature of stepping motors and their differential work in the valve are also considered. The whole servo drive non-linear model is proposed and used further for simulation investigations. The initial simulation investigations of the drive with a new valve have shown that there is a significant overshoot in the drive step response, which is not allowed in positioning process. Therefore additional effort is spent to reduce the overshoot and in consequence reduce the settling time. A special predictive algorithm is proposed to this end. Then the proposed control method is tested and further improved in simulations. Further on, the model is implemented in reality and the whole servo drive system is tested. The investigation results presented in this paper, are showing an overshoot-free positioning process which enables high positioning accuracy.

  7. Driver electronics design and control for a total artificial heart linear motor.

    Science.gov (United States)

    Unthan, Kristin; Cuenca-Navalon, Elena; Pelletier, Benedikt; Finocchiaro, Thomas; Steinseifer, Ulrich

    2018-01-27

    For any implantable device size and efficiency are critical properties. Thus, a linear motor for a Total Artificial Heart was optimized with focus on driver electronics and control strategies. Hardware requirements were defined from power supply and motor setup. Four full bridges were chosen for the power electronics. Shunt resistors were set up for current measurement. Unipolar and bipolar switching for power electronics control were compared regarding current ripple and power losses. Here, unipolar switching showed smaller current ripple and required less power to create the necessary motor forces. Based on calculations for minimal power losses Lorentz force was distributed to the actor's four coils. The distribution was determined as ratio of effective magnetic flux through each coil, which was captured by a force test rig. Static and dynamic measurements under physiological conditions analyzed interaction of control and hardware and all efficiencies were over 89%. In conclusion, the designed electronics, optimized control strategy and applied current distribution create the required motor force and perform optimal under physiological conditions. The developed driver electronics and control offer optimized size and efficiency for any implantable or portable device with multiple independent motor coils. Graphical Abstract ᅟ.

  8. Influence of a high vacuum on the precise positioning using an ultrasonic linear motor.

    Science.gov (United States)

    Kim, Wan-Soo; Lee, Dong-Jin; Lee, Sun-Kyu

    2011-01-01

    This paper presents an investigation of the ultrasonic linear motor stage for use in a high vacuum environment. The slider table is driven by the hybrid bolt-clamped Langevin-type ultrasonic linear motor, which is excited with its different modes of natural frequencies in both lateral and longitudinal directions. In general, the friction behavior in a vacuum environment becomes different from that in an environment of atmospheric pressure and this difference significantly affects the performance of the ultrasonic linear motor. In this paper, to consistently provide stable and high power of output in a high vacuum, frequency matching was conducted. Moreover, to achieve the fine control performance in the vacuum environment, a modified nominal characteristic trajectory following control method was adopted. Finally, the stage was operated under high vacuum condition, and the operating performances were investigated compared with that of a conventional PI compensator. As a result, robustness of positioning was accomplished in a high vacuum condition with nanometer-level accuracy.

  9. Influence of a high vacuum on the precise positioning using an ultrasonic linear motor

    International Nuclear Information System (INIS)

    Kim, Wan-Soo; Lee, Dong-Jin; Lee, Sun-Kyu

    2011-01-01

    This paper presents an investigation of the ultrasonic linear motor stage for use in a high vacuum environment. The slider table is driven by the hybrid bolt-clamped Langevin-type ultrasonic linear motor, which is excited with its different modes of natural frequencies in both lateral and longitudinal directions. In general, the friction behavior in a vacuum environment becomes different from that in an environment of atmospheric pressure and this difference significantly affects the performance of the ultrasonic linear motor. In this paper, to consistently provide stable and high power of output in a high vacuum, frequency matching was conducted. Moreover, to achieve the fine control performance in the vacuum environment, a modified nominal characteristic trajectory following control method was adopted. Finally, the stage was operated under high vacuum condition, and the operating performances were investigated compared with that of a conventional PI compensator. As a result, robustness of positioning was accomplished in a high vacuum condition with nanometer-level accuracy.

  10. Temperature Identification in the Structural Elements of Non-Contacting Face Seals by Using Trefftz Functions

    Directory of Open Access Journals (Sweden)

    Anna PAWIŃSKA

    2014-12-01

    Full Text Available Phenomena of the heat transfer in non-contacting face seals was described by partial differential equation of the second order and boundary conditions. In this way, the mathematical model was developed for the sealing rings. The distributions of temperature in the structural elements was obtained by the Trefftz method. It is a simple method of solving direct and inverse problems described by a homogeneous or an inhomogeneous partial differential equation. The main idea of the method is to determine functions satisfying a given differential equation (Trefftz functions and to fit the linear combination of them to the governing boundary conditions.

  11. CONFIRMATION OF THE MATHEMATICAL MODEL ADEQUACY OF A LINEAR SYNCHRONOUS MOTOR

    Directory of Open Access Journals (Sweden)

    V. F. Novikov

    2015-06-01

    Full Text Available Purpose.To reduce labor costs and the amount of computer time in the design of linear synchronous motors with excitation from a source of a constant magnetic field of high-speed ground transportation it is necessary to use engineering methods. The purpose of this study is to confirm the adequacy of the previously proposed mathematical model of this engine and assumptions. It is also intended to confirm the possibility of applying the method of calculation of traction that occurs in the engine in the interaction of the permanent magnetic field of the excitation system of a vehicle with a coil track structure.Methodology. As for empirical theories the positive result of the experiment is not absolute proof of the truth, for an unambiguous conclusion about the adequacy of the developed model and the effectiveness of the developed methods need to be tested for falsification. In accordance with this criterion, it is necessary to conduct an experiment, the results of which will coincide with the calculation but you also need to avoid errors caused by random coincidences. For this purpose the experiments with varying parameters are conducted. Findings. In a critical experiment configuration changes of the excitation system were held so that the shape dependence of traction from displacement is differed significantly. The comparison of the results of the calculated and experimental values of traction for different configurations showed that the differences are minor and easily explained by measurement error and uneven gaps between the poles and excitation coils of the track structure. Originality. The adequacy of the mathematical model of a linear synchronous motor without a ferromagnetic magnetic circuit and the assumptions and applicability of the calculation method of traction forces involved in it, at the interaction of a permanent magnetic field of the excitation system of a vehicle with a coil track structure were proved. This proof is built on

  12. Magnetically Suspended Linear Pulse Motor for Semiconductor Wafer Transfer in Vacuum Chamber

    Science.gov (United States)

    Moriyama, Shin-Ichi; Hiraki, Naoji; Watanabe, Katsuhide; Kanemitsu, Yoichi

    1996-01-01

    This paper describes a magnetically suspended linear pulse motor for a semiconductor wafer transfer robot in a vacuum chamber. The motor can drive a wafer transfer arm horizontally without mechanical contact. In the construction of the magnetic suspension system, four pairs of linear magnetic bearings for the lift control are used for the guidance control as well. This approach allows us to make the whole motor compact in size and light in weight. The tested motor consists of a double-sided stator and a transfer arm with a width of 50 mm and a total length of 700 mm. The arm, like a ladder in shape, is designed as the floating element with a tooth width of 4 mm (a tooth pitch of 8 mm). The mover mass is limited to about 1.6 kg by adopting such an arm structure, and the ratio of thrust to mover mass reaches to 3.2 N/kg under a broad air gap (1 mm) between the stator teeth and the mover teeth. The performance testing was carried out with a transfer distance less than 450 mm and a transfer speed less than 560 mm/s. The attitude of the arm was well controlled by the linear magnetic bearings with a combined use, and consequently the repeatability on the positioning of the arm reached to about 2 micron. In addition, the positioning accuracy was improved up to about 30 micron through a compensation of the 128-step wave current which was used for the micro-step drive with a step increment of 62.5 micron.

  13. Reliability of the Nidek NT-1000 non contact tonometer.

    Science.gov (United States)

    Van de Velde, T; Zeyen, T

    1995-01-01

    In this prospective study, we compared the intraocular pressure (IOP) readings of 100 patients measured with the Goldmann applanation tonometer and the Nidek NT-1000 pneumotonometer. The correlation coefficient between the Goldmann and Nidek readings was 0.86. On the average the pneumotonometer overestimated the intraocular pressure with 0.43 mm Hg. The Nidek NT-1000 non contact tonometer can be used for screening purposes provided an appropriately low IOP value is used to indicate the need for further assessment with the Goldman applanation tonometer.

  14. [Tonometry with a new non-contact tonometer].

    Science.gov (United States)

    Langmann, G; Schuhmann, G; Langmann, A; Zenz, H

    1990-11-01

    We conducted comparative measurements with 100 healthy probands and patients suffering of glaucoma with both a Goldmann Applanation Tonometer (GAT) and the new Keeler Non Contact Tonometer (NCT). A noticeable conformity of mean values in the group I with values under 23 mm Hg and in group II with values greater or equal 23 mm Hg was obvious. The results of three NCT measurement values were compared with those of four measurements. The Keeler NCT nearly fulfills the needed criteria for the first group with pressure under 23 mm Hg except for a high standard deviation. In group II (pressure greater or equal 23 mm Hg) the demanded nominal values are exceeded.

  15. [Experiences with the non-contact-tonometer (author's transl)].

    Science.gov (United States)

    Dittmar, P; Weinberg, M; Liegl, O

    1975-07-01

    The Non-Contact-Tonometer as developed by the American Optical Corporation, is in use superior to the traditional methods of intraocular-pressure measurements according to Schiötz and Goldmann: Without any manipulation on the eye the intra-ocular pressure can be measured rapidly and easily. Owing to the construction of the tonometer however measurements are only possible with smooth corneae. In addition to this the results of measurement with the NCT are not as exact as those of the traditional methods. Finally there is up to the present no possibility of standardising the new tonometer.

  16. Microwave non-contact imaging of subcutaneous human body tissues.

    Science.gov (United States)

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  17. Algorithm describing pressure distribution of non-contact TNT explosion

    Directory of Open Access Journals (Sweden)

    Radosław Kiciński

    2014-12-01

    Full Text Available [b]Abstract[/b]. The aim of this study is to develop a computational algorithm, describing the shock wave pressure distribution in the space induced by non-contact TNT explosion. The procedure describes pressure distribution on a damp surface of the hull. Simulations have been carried out using Abaqus/CAE. The study also shows the pressure waveform descriptions provided by various authors and presents them in charts. The formulated conclusions convince efficiency of the algorithm application.[b]Keywords:[/b] Underwater explosion, shock wave, CAE, TNT, Kobben class submarine

  18. Novel permanent magnet linear motor with isolated movers: analytical, numerical and experimental study.

    Science.gov (United States)

    Yan, Liang; Peng, Juanjuan; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

    2014-10-01

    This paper proposes a novel permanent magnet linear motor possessing two movers and one stator. The two movers are isolated and can interact with the stator poles to generate independent forces and motions. Compared with conventional multiple motor driving system, it helps to increase the system compactness, and thus improve the power density and working efficiency. The magnetic field distribution is obtained by using equivalent magnetic circuit method. Following that, the formulation of force output considering armature reaction is carried out. Then inductances are analyzed with finite element method to investigate the relationships of the two movers. It is found that the mutual-inductances are nearly equal to zero, and thus the interaction between the two movers is negligible. A research prototype of the linear motor and a measurement apparatus on thrust force have been developed. Both numerical computation and experiment measurement are conducted to validate the analytical model of thrust force. Comparison shows that the analytical model matches the numerical and experimental results well.

  19. Bond Graph Modelling for Fault Detection and Isolation of an Ultrasonic Linear Motor

    Directory of Open Access Journals (Sweden)

    Mabrouk KHEMLICHE

    2010-12-01

    Full Text Available In this paper Bond Graph modeling, simulation and monitoring of ultrasonic linear motors are presented. Only the vibration of piezoelectric ceramics and stator will be taken into account. Contact problems between stator and rotor are not treated here. So, standing and travelling waves will be briefly presented since the majority of the motors use another wave type to generate the stator vibration and thus obtain the elliptic trajectory of the points on the surface of the stator in the first time. Then, electric equivalent circuit will be presented with the aim for giving a general idea of another way of graphical modelling of the vibrator introduced and developed. The simulations of an ultrasonic linear motor are then performed and experimental results on a prototype built at the laboratory are presented. Finally, validation of the Bond Graph method for modelling is carried out, comparing both simulation and experiment results. This paper describes the application of the FDI approach to an electrical system. We demonstrate the FDI effectiveness with real data collected from our automotive test. We introduce the analysis of the problem involved in the faults localization in this process. We propose a method of fault detection applied to the diagnosis and to determine the gravity of a detected fault. We show the possibilities of application of the new approaches to the complex system control.

  20. Optimization and Analysis of a U-Shaped Linear Piezoelectric Ultrasonic Motor Using Longitudinal Transducers.

    Science.gov (United States)

    Yu, Hongpeng; Quan, Qiquan; Tian, Xinqi; Li, He

    2018-03-07

    A novel U-shaped piezoelectric ultrasonic motor that mainly focused on miniaturization and high power density was proposed, fabricated, and tested in this work. The longitudinal vibrations of the transducers were excited to form the elliptical movements on the driving feet. Finite element method (FEM) was used for design and analysis. The resonance frequencies of the selected vibration modes were tuned to be very close to each other with modal analysis and the movement trajectories of the driving feet were gained with transient simulation. The vibration modes and the mechanical output abilities were tested to evaluate the proposed motor further by a prototype. The maximum output speed was tested to be 416 mm/s, the maximum thrust force was 21 N, and the maximum output power was 5.453 W under frequency of 29.52 kHz and voltage of 100 V rms . The maximum output power density of the prototype reached 7.59 W/kg, which was even greater than a previous similar motor under the exciting voltage of 200 V rms . The proposed motor showed great potential for linear driving of large thrust force and high power density.

  1. Population decoding of motor cortical activity using a generalized linear model with hidden states.

    Science.gov (United States)

    Lawhern, Vernon; Wu, Wei; Hatsopoulos, Nicholas; Paninski, Liam

    2010-06-15

    Generalized linear models (GLMs) have been developed for modeling and decoding population neuronal spiking activity in the motor cortex. These models provide reasonable characterizations between neural activity and motor behavior. However, they lack a description of movement-related terms which are not observed directly in these experiments, such as muscular activation, the subject's level of attention, and other internal or external states. Here we propose to include a multi-dimensional hidden state to address these states in a GLM framework where the spike count at each time is described as a function of the hand state (position, velocity, and acceleration), truncated spike history, and the hidden state. The model can be identified by an Expectation-Maximization algorithm. We tested this new method in two datasets where spikes were simultaneously recorded using a multi-electrode array in the primary motor cortex of two monkeys. It was found that this method significantly improves the model-fitting over the classical GLM, for hidden dimensions varying from 1 to 4. This method also provides more accurate decoding of hand state (reducing the mean square error by up to 29% in some cases), while retaining real-time computational efficiency. These improvements on representation and decoding over the classical GLM model suggest that this new approach could contribute as a useful tool to motor cortical decoding and prosthetic applications. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  2. Population Decoding of Motor Cortical Activity using a Generalized Linear Model with Hidden States

    Science.gov (United States)

    Lawhern, Vernon; Wu, Wei; Hatsopoulos, Nicholas G.; Paninski, Liam

    2010-01-01

    Generalized linear models (GLMs) have been developed for modeling and decoding population neuronal spiking activity in the motor cortex. These models provide reasonable characterizations between neural activity and motor behavior. However, they lack a description of movement-related terms which are not observed directly in these experiments, such as muscular activation, the subject's level of attention, and other internal or external states. Here we propose to include a multi-dimensional hidden state to address these states in a GLM framework where the spike count at each time is described as a function of the hand state (position, velocity, and acceleration), truncated spike history, and the hidden state. The model can be identified by an Expectation-Maximization algorithm. We tested this new method in two datasets where spikes were simultaneously recorded using a multi-electrode array in the primary motor cortex of two monkeys. It was found that this method significantly improves the model-fitting over the classical GLM, for hidden dimensions varying from 1 to 4. This method also provides more accurate decoding of hand state (lowering the Mean Square Error by up to 29% in some cases), while retaining real-time computational efficiency. These improvements on representation and decoding over the classical GLM model suggest that this new approach could contribute as a useful tool to motor cortical decoding and prosthetic applications. PMID:20359500

  3. A Low Mass Translation Mechanism for Planetary FTIR Spectrometry using an Ultrasonic Piezo Linear Motor

    Science.gov (United States)

    Heverly, Matthew; Dougherty, Sean; Toon, Geoffrey; Soto, Alejandro; Blavier, Jean-Francois

    2004-01-01

    One of the key components of a Fourier Transform Infrared Spectrometer (FTIR) is the linear translation stage used to vary the optical path length between the two arms of the interferometer. This translation mechanism must produce extremely constant velocity motion across its entire range of travel to allow the instrument to attain high signal-to-noise ratio and spectral resolving power. A new spectrometer is being developed at the Jet Propulsion Laboratory under NASA s Planetary Instrument Definition and Development Program (PIDDP). The goal of this project is to build upon existing spaceborne FTIR spectrometer technology to produce a new instrument prototype that has drastically superior spectral resolution and substantially lower mass, making it feasible for planetary exploration. In order to achieve these goals, Alliance Spacesystems, Inc. (ASI) has developed a linear translation mechanism using a novel ultrasonic piezo linear motor in conjunction with a fully kinematic, fault tolerant linear rail system. The piezo motor provides extremely smooth motion, is inherently redundant, and is capable of producing unlimited travel. The kinematic rail uses spherical Vespel(R). rollers and bushings, which eliminates the need for wet lubrication, while providing a fault tolerant platform for smooth linear motion that will not bind under misalignment or structural deformation. This system can produce velocities from 10 - 100 mm/s with less than 1% velocity error over the entire 100-mm length of travel for a total mechanism mass of less than 850 grams. This system has performed over half a million strokes under vacuum without excessive wear or degradation in performance. This paper covers the design, development, and testing of this linear translation mechanism as part of the Planetary Atmosphere Occultation Spectrometer (PAOS) instrument prototype development program.

  4. Direct torque and flux regulation of synchronous reluctance motor drives based on input-output feedback linearization

    International Nuclear Information System (INIS)

    Abootorabi Zarchi, H.; Arab Markadeh, Gh.R.; Soltani, J.

    2010-01-01

    In this paper, a nonlinear speed tracking controller is introduced for three-phase synchronous reluctance motor (SynRM) on the basis of input-output feedback linearization (IOFL), considering the different control strategies (maximum torque per Ampere, high efficiency and minimum KVA rating for the inverter) related to this motor. The proposed control approach is capable of decoupling control of stator flux and motor generated torque. The validity and effectiveness of the method is verified by simulation and experimental results.

  5. Non-Contact Laser Based Ultrasound Evaluation of Canned Foods

    Science.gov (United States)

    Shelton, David

    2005-03-01

    Laser-Based Ultrasound detection was used to measure the velocity of compression waves transmitted through canned foods. Condensed broth, canned pasta, and non-condensed soup were evaluated in these experiments. Homodyne adaptive optics resulted in measurements that were more accurate than the traditional heterodyne method, as well as yielding a 10 dB gain in signal to noise. A-Scans measured the velocity of ultrasound sent through the center of the can and were able to distinguish the quantity of food stuff in its path, as well as distinguish between meat and potato. B-Scans investigated the heterogeneity of the sample’s contents. The evaluation of canned foods was completely non-contact and would be suitable for continuous monitoring in production. These results were verified by conducting the same experiments with a contact piezo transducer. Although the contact method yields a higher signal to noise ratio than the non-contact method, Laser-Based Ultrasound was able to detect surface waves the contact transducer could not.

  6. Non-Contact Conductivity Measurement for Automated Sample Processing Systems

    Science.gov (United States)

    Beegle, Luther W.; Kirby, James P.

    2012-01-01

    A new method has been developed for monitoring and control of automated sample processing and preparation especially focusing on desalting of samples before analytical analysis (described in more detail in Automated Desalting Apparatus, (NPO-45428), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 44). The use of non-contact conductivity probes, one at the inlet and one at the outlet of the solid phase sample preparation media, allows monitoring of the process, and acts as a trigger for the start of the next step in the sequence (see figure). At each step of the muti-step process, the system is flushed with low-conductivity water, which sets the system back to an overall low-conductivity state. This measurement then triggers the next stage of sample processing protocols, and greatly minimizes use of consumables. In the case of amino acid sample preparation for desalting, the conductivity measurement will define three key conditions for the sample preparation process. First, when the system is neutralized (low conductivity, by washing with excess de-ionized water); second, when the system is acidified, by washing with a strong acid (high conductivity); and third, when the system is at a basic condition of high pH (high conductivity). Taken together, this non-contact conductivity measurement for monitoring sample preparation will not only facilitate automation of the sample preparation and processing, but will also act as a way to optimize the operational time and use of consumables

  7. Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

    Energy Technology Data Exchange (ETDEWEB)

    Tavana, Nariman Roshandel, E-mail: nroshandel@ee.iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Shoulaie, Abbas, E-mail: shoulaie@iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of)

    2011-01-15

    In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

  8. Dynamic diagnostics of moving ferromagnetic material with the linear induction motor

    Directory of Open Access Journals (Sweden)

    Szewczyk Krzysztof

    2017-01-01

    Full Text Available The paper presents the application of a three-phase induction motor as a sensor measuring the force of the electromagnetic field connection between the engine and produced sheet steel. The force interaction between the engine and the manufactured sheet metal treated as a treadmill for a linear motor may be an indicator of damage to the material. Detection of places where the sheet does not meet the quality requirements may be very useful in the production process. FEM calculations were performed in the ANSYS MAXWELL environment. The results suggest the possibility of using this type of construction to test the quality of produced materials. The computational results and their analysis are presented in this article.

  9. Adaptive H∞ nonlinear velocity tracking using RBFNN for linear DC brushless motor

    Science.gov (United States)

    Tsai, Ching-Chih; Chan, Cheng-Kain; Li, Yi Yu

    2012-01-01

    This article presents an adaptive H ∞ nonlinear velocity control for a linear DC brushless motor. A simplified model of this motor with friction is briefly recalled. The friction dynamics is described by the Lu Gre model and the online tuning radial basis function neural network (RBFNN) is used to parameterise the nonlinear friction function and un-modelled errors. An adaptive nonlinear H ∞ control method is then proposed to achieve velocity tracking, by assuming that the upper bounds of the ripple force, the changeable load and the nonlinear friction can be learned by the RBFNN. The closed-loop system is proven to be uniformly bounded using the Lyapunov stability theory. The feasibility and the efficacy of the proposed control are exemplified by conducting two velocity tracking experiments.

  10. An electrostatic 3-phase linear stepper motor fabricated by vertical trench isolation technology

    International Nuclear Information System (INIS)

    Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Fujita, Hiroyuki

    2009-01-01

    We present the design, microfabrication and characterization of an electrostatic 3-phase linear stepper micromotor constructed with vertical trench isolation technology. This suitable technology was used to create a monolithic stepper motor with high-aspect-ratio poles and an integrated 3-phase electrical network in the bulk of a standard single-crystal silicon wafer. The shuttle of the stepper motor is suspended by a flexure to avoid any mechanical contact during operation, enhancing the precision, repeatability and reliability of the stepping motion. The prototype is capable of a maximum travel of +/−26 µm (52 µm) at an actuation voltage of 30 V and a step size of 1.4 µm during a half-stepping sequence

  11. An electrostatic 3-phase linear stepper motor fabricated by vertical trench isolation technology

    Science.gov (United States)

    Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Fujita, Hiroyuki

    2009-07-01

    We present the design, microfabrication and characterization of an electrostatic 3-phase linear stepper micromotor constructed with vertical trench isolation technology. This suitable technology was used to create a monolithic stepper motor with high-aspect-ratio poles and an integrated 3-phase electrical network in the bulk of a standard single-crystal silicon wafer. The shuttle of the stepper motor is suspended by a flexure to avoid any mechanical contact during operation, enhancing the precision, repeatability and reliability of the stepping motion. The prototype is capable of a maximum travel of +/-26 µm (52 µm) at an actuation voltage of 30 V and a step size of 1.4 µm during a half-stepping sequence. This work was presented in part at the 19th MicroMechanics Europe Workshop (MME), 28-30 September 2008, Aachen, Germany.

  12. A linear motor and compact cylinder-piston driver for left ventricular bypass.

    Science.gov (United States)

    Qian, K X

    1990-01-01

    A simple, portable, reliable and noise-free pneumatic driver has been developed. It consists of a linear motor attached to a cylinder piston, in one unit. The motor coil is directly wound on the cylinder, and the permanent magnet is fixed to the piston. As a continuous voltage square wave is applied to the coil, the cylinder reciprocates on the piston periodically, producing air pressure and vacuum alternately. In conjunction with a locally made diaphragm pump, the driver was tested in vitro and in vivo. Results demonstrated that the device could drive the diaphragm pump and so support the circulation of an experimental animal. The driver weighs 12 kg. For 200 mmHg air pressure and -80 mmHg vacuum the power consumed is 30 W. Its noise is about 30 dB, less than that of an artificial valve and pump.

  13. Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

    International Nuclear Information System (INIS)

    Tavana, Nariman Roshandel; Shoulaie, Abbas

    2011-01-01

    In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

  14. Magnetically levitated railway with common reaction rail for a linear motor drive and an electro dynamic side guidance arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, R

    1977-04-07

    The invention concerns a magnetically levitated railway with common reaction rail for the linear motor drive and the electrical side guidance arrangement. While the electro-dynamic hovering process requires a high electrical conductivity of the reaction rails in order to reduce eddy current losses, these should show a relatively high resistance for the asynchronous linear motor to reduce losses of propelling force. These contradictory requirements can be fulfilled for a common reaction rail made of homogeneous material of high electrical conductivity according to the invention, by providing slits at right angles to the driving axis in the part of the reaction rail allocated to the linear motor. Thus the guidance system retains a low ohmic resistance, while the part of the reaction rail allocated to the windings of the linear motor has a relatively low ohmic secondary resistance, by which the border and end effects which reduce the propelling force can be appreciably reduced.

  15. Simulation of magnetic induction distribution in a coaxial linear motor with axial and radial direction of permanent magnets magnetization

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-03-01

    Full Text Available The paper presents results of computer simulation and experimental study of magnetic induction distribution in a coaxial linear motor air gap throughout the length of the runner active part at different heights of the air gap between the runner and the inductor magnetic core for motors with axial and radial direction of the permanent magnets magnetization.

  16. Air-gap field, induced voltage and thrust in the short-stator linear induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Deleroi, W

    1980-07-15

    The description of the magnetic field in the air-gap of a short-primary linear induction motor, and the subsequent calculation of the thrust developed and the voltages induced in the stator bars can be made by using balancing waves. These balancing waves are generated at any point where the field wave that would exist in a machine of infinite length is disturbed. In the linear motor these disturbances occur at the ends of the stator iron and at discontinuities in the distribution of the stator winding, which exist in machines having stepped windings. From the points where they are generated, free balancing waves travel in two directions and determine the performance of these machines to a large extent. The voltage they induce in a stator bar can be determined from the core flux and mapped on a phasor diagram. The resulting voltage phasor follows a logarithmic spiral. The resulting voltages induced in the three phase windings form a strongly asymmetrical system which can be split-up into positive-, negative- and zerosequence components depending on the slip. The tangential forces may be calculated as the product of the magnetic flux density in the air-gap and the linear current density in either the stator or the reaction rail. As the 'magnetic tail' outside the machine also gives rise to forces in the direction of motion, both methods yield quite different force distributions, though for the resulting force the same value is found.

  17. A study on stable levitation of permanent magnet transportation system with coreless linear synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Hiwaki, H [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Watada, M [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Torii, S [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan); Ebihara, D [Dept. of Electrical and Electronic Engineering, Musashi Inst. of Technology, Tokyo (Japan)

    1996-12-31

    In the permanent magnet levitation system, it is impossible to stabilize the motion of the vehicle in both levitation and guidance directions only by permanent magnet. Therefore, the authors proposed the combined system of permanent magnet for levitation and coreless linear synchronous motor (coreless LSM). To design the coreless coils for LSM, the method to calculate the spring coefficient between coreless coil and permanent magnet for LSM is shown. By using this method, the spring coefficients of the three coil arrangements are compared and coreless coil is designed. Furthermore, the authors showed the possibility of stabilizing the motion of the levitation system with coreless LSM. (orig.)

  18. A new double sided linear switched reluctance motor with low cost

    International Nuclear Information System (INIS)

    Daldaban, Ferhat; Ustkoyuncu, Nurettin

    2006-01-01

    This paper presents the realization and design of a new linear switched reluctance motor (LSRM) structure. The new model has double sided configuration and provides high force for many applications with low cost. The characteristics of the LSRM are obtained by using finite element analysis (FEA) and analytical calculations. The results of the FEA and analytical calculations are presented, and compared with experimental results. A high correlation between experimental and analytical results is obtained, which has been demonstrated in the form of inductance versus position versus current

  19. Experimental Analysis of Linear Induction Motor under Variable Voltage Variable Frequency (VVVF Power Supply

    Directory of Open Access Journals (Sweden)

    Prasenjit D. Wakode

    2016-07-01

    Full Text Available This paper presents the complete analysis of Linear Induction Motor (LIM under VVVF. The complete variation of LIM air gap flux under ‘blocked Linor’ condition and starting force is analyzed and presented when LIM is given VVVF supply. The analysis of this data is important in further understanding of the equivalent circuit parameters of LIM and to study the magnetic circuit of LIM. The variation of these parameters is important to know the LIM response at different frequencies. The simulation and application of different control strategies such as vector control thus becomes quite easy to apply and understand motor’s response under such strategy of control.

  20. Decentralized control of the COFS-I Mast using linear dc motors

    Science.gov (United States)

    Lindner, Douglas K.; Celano, Tom; Ide, Eric

    1989-01-01

    Consideration is given to a decentralized control design for vibration suppression in the COFS-I Mast using linear dc motors for actuators. The decentralized control design is based results from power systems using root locus techniques that are not well known. The approach is effective because the loop gain is low due to low actuator authority. The frequency-dependent nonlinearities of the actuator are taken into account. Because of the tendency of the transients to saturate the the stroke length of the actuator, its effectiveness is limited.

  1. Incremental Adaptive Fuzzy Control for Sensorless Stroke Control of A Halbach-type Linear Oscillatory Motor

    Science.gov (United States)

    Lei, Meizhen; Wang, Liqiang

    2018-01-01

    The halbach-type linear oscillatory motor (HT-LOM) is multi-variable, highly coupled, nonlinear and uncertain, and difficult to get a satisfied result by conventional PID control. An incremental adaptive fuzzy controller (IAFC) for stroke tracking was presented, which combined the merits of PID control, the fuzzy inference mechanism and the adaptive algorithm. The integral-operation is added to the conventional fuzzy control algorithm. The fuzzy scale factor can be online tuned according to the load force and stroke command. The simulation results indicate that the proposed control scheme can achieve satisfied stroke tracking performance and is robust with respect to parameter variations and external disturbance.

  2. Improvement of superconducting cylindrical linear induction motor; Chodendo entokeitan ichiji rinia yudo mota no tokusei kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kikuma, T.; Tomita, M.; Ishiyama, A. [Waseda Univ., Tokyo (Japan)

    1999-11-10

    For the purpose of we examining the effect of characteristics and ac loss under real machine operating environment of the alternating current superconductivity winding for a realization of the superconductive AC machine vessel, cylindrical shortness first linear guiding motor which used NbTi/CuNi superconducting cable for the primary winding was produced experimentally. The coil number was increased from 6 in 14 this time, and the optimization of the primary current was done, and the improvement on characteristics was attempted. Here, starting torque characteristics, quenching detection protection control circuit are reported. (NEDO)

  3. Particle Swarm Based Approach of a Real-Time Discrete Neural Identifier for Linear Induction Motors

    Directory of Open Access Journals (Sweden)

    Alma Y. Alanis

    2013-01-01

    Full Text Available This paper focusses on a discrete-time neural identifier applied to a linear induction motor (LIM model, whose model is assumed to be unknown. This neural identifier is robust in presence of external and internal uncertainties. The proposed scheme is based on a discrete-time recurrent high-order neural network (RHONN trained with a novel algorithm based on extended Kalman filter (EKF and particle swarm optimization (PSO, using an online series-parallel con…figuration. Real-time results are included in order to illustrate the applicability of the proposed scheme.

  4. Non-contact measurement of rotation angle with solo camera

    Science.gov (United States)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  5. Non-contact feature detection using ultrasonic Lamb waves

    Science.gov (United States)

    Sinha, Dipen N [Los Alamos, NM

    2011-06-28

    Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

  6. Non-contact biopotential sensor for remote human detection

    Energy Technology Data Exchange (ETDEWEB)

    Mahdi, A E [Department of Electronic and Computer Engineering, University of Limerick, Limerick (Ireland); Faggion, L, E-mail: hussain.mahdi@ul.ie, E-mail: lorenzo.faggion@jrc.ec.europa.eu [Joint Research Centre of the European Commission, Institute for the Protection and Safety of the Citizen, Ispra (Italy)

    2011-08-17

    This paper describes a new low-cost, low-noise displacement current sensor developed for non-contact measurements of human biopotentials and well suited for detection of human presence applications. The sensor employs a simple, improvised transimpedance amplifier that eliminates the need for ultra high values resistors normally needed in current amplifiers required for this type of measurements. The sensor provides an operational bandwidth of 0.5 - 250 Hz, and a noise level of 7.8{mu}V{radical}Hz at 1 Hz down to 30nV/{radical}Hz at 1 kHz. Reported experimental results demonstrate the sensor's capability in measuring heart related biopotentials within 0.5m off-body distance, and muscle related biopotentials within 10m no obstacles off-body distance, and 5m off-body distance with a concrete wall in between.

  7. Numerical analysis of the non-contacting gas face seals

    Science.gov (United States)

    Blasiak, S.

    2017-08-01

    The non-contacting gas face seals are used in high-performance devices where the main requirements are safety and reliability. Compliance with these requirements is made possible by careful research and analysis of physical processes related to, inter alia, fluid flow through the radial gap and ring oscillations susceptible to being housed in the enclosure under the influence of rotor kinematic forces. Elaborating and developing mathematical models describing these phenomena allows for more and more accurate analysis results. The paper presents results of studies on stationary ring oscillations made of different types of materials. The presented results of the research allow to determine which of the materials used causes the greatest amplitude of the vibration of the system fluid film-working rings.

  8. Automatic Human Movement Assessment With Switching Linear Dynamic System: Motion Segmentation and Motor Performance.

    Science.gov (United States)

    de Souza Baptista, Roberto; Bo, Antonio P L; Hayashibe, Mitsuhiro

    2017-06-01

    Performance assessment of human movement is critical in diagnosis and motor-control rehabilitation. Recent developments in portable sensor technology enable clinicians to measure spatiotemporal aspects to aid in the neurological assessment. However, the extraction of quantitative information from such measurements is usually done manually through visual inspection. This paper presents a novel framework for automatic human movement assessment that executes segmentation and motor performance parameter extraction in time-series of measurements from a sequence of human movements. We use the elements of a Switching Linear Dynamic System model as building blocks to translate formal definitions and procedures from human movement analysis. Our approach provides a method for users with no expertise in signal processing to create models for movements using labeled dataset and later use it for automatic assessment. We validated our framework on preliminary tests involving six healthy adult subjects that executed common movements in functional tests and rehabilitation exercise sessions, such as sit-to-stand and lateral elevation of the arms and five elderly subjects, two of which with limited mobility, that executed the sit-to-stand movement. The proposed method worked on random motion sequences for the dual purpose of movement segmentation (accuracy of 72%-100%) and motor performance assessment (mean error of 0%-12%).

  9. The Experimental Study of Rayleigh-Taylor Instability using a Linear Induction Motor Accelerator

    Science.gov (United States)

    Yamashita, Nicholas; Jacobs, Jeffrey

    2009-11-01

    The experiments to be presented utilize an incompressible system of two stratified miscible liquids of different densities that are accelerated in order to produce the Rayleigh-Taylor instability. Three liquid combinations are used: isopropyl alcohol with water, a calcium nitrate solution or a lithium polytungstate solution, giving Atwood numbers of 0.11, 0.22 and 0.57, respectively. The acceleration required to drive the instability is produced by two high-speed linear induction motors mounted to an 8 m tall drop tower. The motors are mounted in parallel and have an effective acceleration length of 1.7 m and are each capable of producing 15 kN of thrust. The liquid system is contained within a square acrylic tank with inside dimensions 76 x76x184 mm. The tank is mounted to an aluminum plate, which is driven by the motors to create constant accelerations in the range of 1-20 g's, though the potential exists for higher accelerations. Also attached to the plate are a high-speed camera and an LED backlight to provide continuous video of the instability. In addition, an accelerometer is used to provide acceleration measurements during each experiment. Experimental image sequences will be presented which show the development of a random three-dimensional instability from an unforced initial perturbation. Measurements of the mixing zone width will be compared with traditional growth models.

  10. Dosage-dependent non-linear effect of L-dopa on human motor cortex plasticity.

    Science.gov (United States)

    Monte-Silva, Katia; Liebetanz, David; Grundey, Jessica; Paulus, Walter; Nitsche, Michael A

    2010-09-15

    The neuromodulator dopamine affects learning and memory formation and their likely physiological correlates, long-term depression and potentiation, in animals and humans. It is known from animal experiments that dopamine exerts a dosage-dependent, inverted U-shaped effect on these functions. However, this has not been explored in humans so far. In order to reveal a non-linear dose-dependent effect of dopamine on cortical plasticity in humans, we explored the impact of 25, 100 and 200 mg of L-dopa on transcranial direct current (tDCS)-induced plasticity in twelve healthy human subjects. The primary motor cortex served as a model system, and plasticity was monitored by motor evoked potential amplitudes elicited by transcranial magnetic stimulation. As compared to placebo medication, low and high dosages of L-dopa abolished facilitatory as well as inhibitory plasticity, whereas the medium dosage prolonged inhibitory plasticity, and turned facilitatory plasticity into inhibition. Thus the results show clear non-linear, dosage-dependent effects of dopamine on both facilitatory and inhibitory plasticity, and support the assumption of the importance of a specific dosage of dopamine optimally suited to improve plasticity. This might be important for the therapeutic application of dopaminergic agents, especially for rehabilitative purposes, and explain some opposing results in former studies.

  11. CEDM Controller for a Linear Pulse Motor by using Pulse Width Modulation Method in Integral Reactor

    International Nuclear Information System (INIS)

    Lee, Joon-Koo; Keum, Jong-Yong; Park, Heui-Youn

    2007-01-01

    Integral Reactor SMART is under development at KAERI. The design characteristics of SMART are radically different from those employed in currently operating loop type PWR in Korea. The reliability and accuracy of Control Rod Drive Mechanism are very important to the reactor safety and the design of the Plant Protection System. The SMART CEDM designed for fine-step movement consists of a linear pulse motor, reed switch type sensor with top and bottom limit switches which also act as Control Element Assembly(CEA) Position indicator, The linear pulse motor is a four phase synchronous DC electric machine with inner stator and output stator in coolant medium inside a strong housing. The objective of this paper is to introduce and to explain the CEDM controller CEDM Controller is being developed with a new design concept and digital technology to reduce the Operating Error and improve the systems' reliability and availability. And Switched Mode Power Supply is also being developed with digital hardware technology. This paper involves the test details and result

  12. Linear hypergeneralization of learned dynamics across movement speeds reveals anisotropic, gain-encoding primitives for motor adaptation.

    Science.gov (United States)

    Joiner, Wilsaan M; Ajayi, Obafunso; Sing, Gary C; Smith, Maurice A

    2011-01-01

    The ability to generalize learned motor actions to new contexts is a key feature of the motor system. For example, the ability to ride a bicycle or swing a racket is often first developed at lower speeds and later applied to faster velocities. A number of previous studies have examined the generalization of motor adaptation across movement directions and found that the learned adaptation decays in a pattern consistent with the existence of motor primitives that display narrow Gaussian tuning. However, few studies have examined the generalization of motor adaptation across movement speeds. Following adaptation to linear velocity-dependent dynamics during point-to-point reaching arm movements at one speed, we tested the ability of subjects to transfer this adaptation to short-duration higher-speed movements aimed at the same target. We found near-perfect linear extrapolation of the trained adaptation with respect to both the magnitude and the time course of the velocity profiles associated with the high-speed movements: a 69% increase in movement speed corresponded to a 74% extrapolation of the trained adaptation. The close match between the increase in movement speed and the corresponding increase in adaptation beyond what was trained indicates linear hypergeneralization. Computational modeling shows that this pattern of linear hypergeneralization across movement speeds is not compatible with previous models of adaptation in which motor primitives display isotropic Gaussian tuning of motor output around their preferred velocities. Instead, we show that this generalization pattern indicates that the primitives involved in the adaptation to viscous dynamics display anisotropic tuning in velocity space and encode the gain between motor output and motion state rather than motor output itself.

  13. Profile measurement of a bent neutron mirror using an ultrahigh precision non-contact measurement system with an auto focus laser probe

    International Nuclear Information System (INIS)

    Morita, S; Guo, J; Yamagata, Y; Yamada, N L; Torikai, N; Takeda, S; Furusaka, M

    2016-01-01

    A bent neutron mirror has been considered as one of the best solutions for focusing neutron beams from the viewpoint of cost-benefit performance. Although the form deviation of the bent profile is expected because of the large spot size, it is difficult to measure due to its geometric limitation. Here, we propose a non-contact measurement system using an auto focus (AF) laser probe on an ultrahigh precision machine tool to precisely evaluate the form deviation of the bent mirror. The AF laser probe is composed of a diode laser, a position sensitive sensor, a charge-coupled device (CCD) camera and a microscope objective lens which is actuated by an electromagnetic motor with 1 nm resolution for position sensing and control. The sensor enables a non-contact profile measurement of a high precision surface without any surface damage in contrast with contact-type ultrahigh precision coordinate measurement machines with ruby styli. In the on-machine measurement system, a personal computer simultaneously acquires a displacement signal from the AF laser probe and 3-axis positional coordinates of the ultrahigh machine tool branched between the linear laser scales and the numerical controller. The acquisition rate of the 4-axis positional data in 1 nm resolution is more than 10 Hz and the simultaneity between the axes is negligible. The profile of a neutron bent mirror was measured from a transparent side using the developed system, and the result proves that the form deviation of the mirror enlarged the the spot size of focused neuron beam. (paper)

  14. Some image artefacts in non-contact mode force microscopy

    International Nuclear Information System (INIS)

    Dinte, B.P.; Watson, G.S.; Dobson, J.F.; Myhra, S.

    1996-01-01

    Full text: Non-contact mode Atomic Force Microscopy (AFM), performed in air, of two-dimensional hexagonal close-packed (2DHCP) layers of 200 nm diameter polystyrene spheres yields images containing artefacts ('ghost spheres') at layer edges and vacancy sites. The origin of these artefacts is clearly not the simple convolution of the tip and sample geometries, but must be the interaction between them. A computer program was written to simulate the experimental contours, assuming that the only force between the tip and the sample is the van der Waals (dispersion) force, and that the contours traced by the AFM tip are those of constant force derivative. The energy was calculated by integrating R -6 over the volumes of the tip and the sample, with a (constant) arbitrary scaling factor. The experimental contours were reproduced by the simulations, except for the 'ghost' artefacts. The assumption that there is only a dispersion force is thus incorrect. The experiments were performed in air, so that all surfaces were coated by a layer of adsorbed moisture. It is proposed that meniscus forces may be the origin of the artefacts

  15. Non-contact tensile viscoelastic characterization of microscale biological materials

    Science.gov (United States)

    Li, Yuhui; Hong, Yuan; Xu, Guang-Kui; Liu, Shaobao; Shi, Qiang; Tang, Deding; Yang, Hui; Genin, Guy M.; Lu, Tian Jian; Xu, Feng

    2018-06-01

    Many structures and materials in nature and physiology have important "meso-scale" structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.

  16. Non-contact wearable single forearm cardiac biopotential acquisition device

    International Nuclear Information System (INIS)

    Gonçalves, Sérgio; Martins, Raul Carneiro

    2013-01-01

    In this work the authors propose a novel approach to obtain the electrocardiogram in the forearm using non-contact sensing. This new solution should be at same time portable, ergonomic and robust, enabling its use in different set of applications. A system of four electrodes was used in an adjustable sleeve to be wrapped in the forearm. No additional electrode references were used in other body parts. In order to increase the sensitivity of the system, an harmonium like approach was used in the design of the electrodes. The prototype was then compared with a similar system with a flat conformation. The developed prototype enabled the acquisition of an ECG signal in the forearm and the inclusion of the harmonium like electrode conformation resulted in a considerable increase of the sensitivity of the system. The acquired signal did not enable the identification of all characteristic cardiac waves. However, it was possible to identify clearly a signal pattern, characteristic of the QRS complex. The properties of the acquired signal restrict their use in rigorous electrocardiographic studies, allowing, however, its application in heart rate variability monitoring and biometric identification without the disadvantages usually associated with conventional electrodes. This makes it specially useful for man-machine interfaces and automated identification

  17. Analysis of a non-contact magnetoelastic torque transducer

    International Nuclear Information System (INIS)

    Andreescu, R.; Spellman, B.; Furlani, E.P.

    2008-01-01

    Results are presented for the performance of a magnetoelastic torque transducer that converts a torque-induced strain in a non-magnetic shaft into changes in a measurable magnetic field. The magnetic field is generated by a thin magnetostrictive layer that is coated onto the circumference of the shaft. The layer is magnetized and has an initial residual strain. The magnetization within the layer rotates in response to changes in the strain which occur when the shaft is torqued. The magnetic field produced by the layer changes with the magnetization and this can be sensed by a magnetometer to monitor the torque on the shaft. In this paper, a phenomenological theory is developed for predicting the performance of the transducer. The theory can be used to predict the magnetic field distribution of the transducer as a function of the physical properties of the magnetic coating, its residual strain, and the applied torque. It enables rapid parametric analysis of transducer performance, which is useful for the development and optimization of novel non-contact torque sensors

  18. Clinical evaluation of the Non-Contact Tonometer Mark II.

    Science.gov (United States)

    Chauhan, B C; Henson, D B

    1988-09-01

    The purpose of this investigation was to test the reliability of the American Optical Non-Contact Tonometer Mark II (NCT II) using the Goldmann Applanation Tonometer (GAT) as the validating instrument. The sample contained 102 consecutive patients from our University Eye Clinic, of whom one-half had 4 NCT II measurements first, followed by 4 GAT measurements; the other one-half had 4 GAT measurements first, followed by 4 NCT II measurements. No significant change in intraocular pressure (IOP) was noted over the measurement sequence with either instrument. There was no significant difference between paired NCT II and GAT readings when the NCT II was used first; however, a highly significant difference between paired readings was obtained when the GAT was used first, indicating that the GAT measurement produced a delayed reduction in the IOP. This effect did not occur with the NCT II. Although the NCT II is shown to have a good overall reliability when compared to the GAT in both protocols, the agreement between any two tonometers may be influenced greatly by the very process of taking a measurement and by the dynamic nature of the IOP.

  19. Non-Contact Measurements of Creep Properties of Refractory Materials

    Science.gov (United States)

    Lee, Jonghyun; Bradshaw, Richard C.; Hyers, Robert W.; Rogers, Jan R.; Rathz, Thomas J.; Wall, James J.; Choo, Hahn; Liaw, Peter

    2006-01-01

    State-of-the-art technologies for hypersonic aircraft, nuclear electric/thermal propulsion for spacecraft, and more efficient jet engines are driving ever more demanding needs for high-temperature (>2000 C) materials. At such high temperatures, creep rises as one of the most important design factors to be considered. Since conventional measurement techniques for creep resistance are limited to about 17OO0C, a new technique is in demand for higher temperatures. This paper presents a non-contact method using electrostatic levitation (ESL) which is applicable to both metallic and non-metallic materials. The samples were rotated quickly enough to cause creep deformation by centrifugal acceleration. The deformation of the samples was captured with a high speed camera and then the images were analyzed to estimate creep resistance. Finite element analyses were performed and compared to the experiments to verify the new method. Results are presented for niobium and tungsten, representative refractory materials at 2300 C and 2700 C respectively.

  20. Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

    International Nuclear Information System (INIS)

    Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

    2017-01-01

    According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable. (paper)

  1. Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

    Science.gov (United States)

    Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

    2017-07-01

    According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable.

  2. Rail Brake System Using a Linear Induction Motor for Dynamic Braking

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Tanaka, Minoru; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. In this paper, we estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system.

  3. Analysis and measure of novel stereo-garage driven by linear induction motor

    Directory of Open Access Journals (Sweden)

    Lu Qinfen

    2015-12-01

    Full Text Available The car access time is a key parameter, especially in a huge stereo-garage, where this one should be decreased as much as possible. This paper proposes a novel stereo-garage. Adopting the linear induction motors (LIMs, the system has a simple structure and rapid response capability. In the stereo-garage, several LIMs are installed below the crossbeam on a lifting platform, and several LIMs are fixed on the top of a moving frame. During the operation of LIMs, the moving frame moves forward and backward to reach the required parking place, whereas the crossbeam moves horizontally in order to take or store the vehicle rapidly. All these LIMs are the same and should be designed at a low frequency. The influences of key structure parameters and dynamic performances are investigated, based on FEM. The predicted results are validated by a prototype. Finally, the designed LIMs are successfully applied in two 8-layer stereo-garages.

  4. Recession in a linear stepper motor based on piezoelectric actuator and electrorheological clampers

    International Nuclear Information System (INIS)

    Li, Cuihong; Meng, Yonggang; Tian, Yu

    2012-01-01

    A linear inchworm-type stepper motor based on piezoelectric actuator and comb shape electrorheological (ER) clampers was developed and tested. A recession phenomenon in the movement of the motor was found and was significantly affected by the driving voltage of the piezoelectric actuator and ER fluids. A dynamic model to analyze the mechanism of the recession was established. The force ratio of the viscoelastic clamping force (applied high electric field) to the viscous damping force (zero field) of ER fluids is the critical factor which determines the recession. The ratio is also affected by the extension or contraction rate of the actuator during movement, which is affected by the charging and discharging processes. With a relatively large distance between the clamper electrodes and a small displacement activated by the extension of the piezoelectric actuator, the instantaneous shear rate might not be sufficiently high, preventing ER fluids from attaining a shear-thickened and high-strength state. The ratio of yield strength to the viscous strength of ER fluids during movement should be as large as possible to reduce the recession displacement. (paper)

  5. A novel L-shaped linear ultrasonic motor operating in a single resonance mode

    Science.gov (United States)

    Zhang, Bailiang; Yao, Zhiyuan; Liu, Zhen; Li, Xiaoniu

    2018-01-01

    In this study, a large thrust linear ultrasonic motor using an L-shaped stator is described. The stator is constructed by two mutually perpendicular rectangular plate vibrators, one of which is mounted in parallel with the slider to make the motor structure to be more compact. The symmetric and antisymmetric modes of the stator based on the first order bending vibration of two vibrators are adopted, in which each resonance mode is assigned to drive the slider in one direction. The placement of piezoelectric ceramics in a stator could be determined by finite element analysis, and the influence of slots in the head block on the vibration amplitudes of driving foot was studied as well. Three types of prototypes (non-slotted, dual-slot, and single-slot) were fabricated and experimentally investigated. Experimental results demonstrated that the prototype with one slot exhibited the best mechanical output performance. The maximum loads under the excitation of symmetric mode and antisymmetric mode were 65 and 90 N, respectively.

  6. A piezoelectric linear ultrasonic motor with the structure of a circular cylindrical stator and slider

    International Nuclear Information System (INIS)

    Sun, Dongming; Wang, Sheng; Sakurai, Junpei; Hata, Seiichi; Choi, Kee-Bong; Shimokohbe, Akira

    2010-01-01

    A piezoelectric linear ultrasonic motor is proposed, with a cylindrical stator and slider structure. The length and diameter of the motor are about 10 and 1.5 mm, respectively. The stator consists of two piezoelectric ceramic (PZT) tubes connected by a thin film metallic glass (TFMG) pipe. The stator is designed based on theoretical analyses and finite element method (FEM) simulation. The traveling wave propagation is obtained in the FEM simulation under the proper geometrical sizes, suitable boundary conditions and driving voltage signals. The trajectories of particles on the TFMG pipe are elliptical motion. In the experiment, a 25 µm thick TFMG pipe is fabricated using the rotating magnetron sputtering technique and the vibration characteristics of the stator are measured by a laser Doppler vibrometer (LDV) system. Bidirectional motion of the slider is observed around 600 kHz, the maximum velocity is near to 40 mm s −1 at 50 Vp–p for the loose slider and the maximum output force is 6 mN at 70 Vp–p for the tight slider

  7. A non-contact shape measuring system using an artificial neural network

    International Nuclear Information System (INIS)

    Jeon, Woo Tae; Lee, Myung Chan; Koh, Duck Joon; Cho, Hyung Suck

    1996-01-01

    We developed a non-contact shape measuring device using computer image processing technology. We present a method of calibrating a CCD video camera and a laser range finder which is the most important step toward making an accurate shape measuring system. An artificial neural network is used for the calibration. Our measurement system is composed of a semiconductor laser, a CCD video camera, a personal computer, and a linear motion table. We think that the developed system could be used for measuring the change in shape of the spent nuclear fuel rod before and after irradiation which is one of the most important tasks for developing a better nuclear fuel. A radiation shield is suggested for the possible utilization of the range finder in radioactive environment

  8. Comparison of the Keeler Pulsair 2000 non-contact tonometer with Goldmann applanation.

    Science.gov (United States)

    Moseley, M J; Thompson, J R; Deutsch, J; Misson, G P; Naylor, G; Tan-Yee, A; Taylor, R H; Fielder, A R

    1993-01-01

    The Pulsair 2000 non-contact tonometer (Keeler Ltd, UK) is compared with the Goldmann applanation tonometer. Data from 80 eyes were acquired by four experienced observers. A linear regression analysis showed the relationship between the instruments to be: Pulsair = 0.66 + 0.95 Goldmann. Individual components of variation were analysed by analysis of variance which indicated a significant variation in the slope of the regression equation due to observers (p = 0.02) but not to the order in which topical anaesthesia was administered. Differences between two Pulsair instruments were of marginal significance (p = 0.07). The intercept of the regression equation was unaffected by any of the components of variation. Seventy-nine per cent of averaged intraocular pressure measurements obtained with the Pulsair 2000 fell on or within +/- 3 mmHg of those measured with the Goldmann tonometer. It is concluded that the Pulsair 2000 can provide clinically useful measurements of intraocular pressure.

  9. Development of linear pulse motor type control element drive mechanism for smart

    International Nuclear Information System (INIS)

    Je-Yong, Yu; Jong-in, Kim; Ji-ho, Kim; Hyung, Huh; Moon-Hee, Chang

    2001-01-01

    The system-integrated modular advanced reactor (SMART) currently under development at the Korea Atomic Energy Research Institute is being designed with soluble boron free operation and the use of nuclear heating for reactor start-up. These design features require a Control Element Drive Mechanism(CEDM) for SMART to have fine-step movement capability as well as high reliability for fine reactivity control. In this paper, the design characteristics of a new concept CEDM driven by a Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on computer. A prototype of the LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between the inner stator and outer stator. The thrust forces of LPM predicted by the analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and a simple drive mechanism to reduce volume and satisfy reactor operating circumstances with high pressure and temperature. (authors)

  10. Linear pulse motor type control element drive mechanism for the integral reactor

    International Nuclear Information System (INIS)

    Yu, J. Y.; Choi, S.; Kim, J. H.; Huh, H.; Park, K. B.

    2007-01-01

    The integral reactor SMART currently under development at Korea Atomic Energy Research Institute is designed with soluble boron free operation and use of nuclear heating for reactor startup. These design features require the Control Element Drive Mechanism (CEDM) for SMART to have fine-step movement capability as well as high reliability for the fine reactivity control. In this paper, design characteristics of a new concept CEDM driven by the Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by the electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on the computer. Prototype of LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and a test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between inner stator and outer stator. The thrust forces of LPM predicted by analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and simple drive mechanism to reduce volume and satisfy the reactor operating circumstances with high pressure and temperature

  11. Novel Synchronous Linear and Rotatory Micro Motors Based on Polymer Magnets with Organic and Inorganic Insulation Layers

    Directory of Open Access Journals (Sweden)

    Andreas WALDSCHIK

    2008-12-01

    Full Text Available In this work, we report on the development of several synchronous motors with rotatory or linear movements. The synchronous micro motors are brushless DC motors or stepper motors with electrically controlled commutation consisting of a stator and a rotor. The rotor is mounted onto the stator and is adjusted by an integrated guidance. Inside the stator different coil systems are realized, like double layer sector coils or special nested coils. The coil systems can be controlled by three or six phases depending on the operational mode. Furthermore, inorganic insulation layers were used in order to reduce the thickness of the system. By this means four layers of electrical conductors can be realized especially for the 2D devices. The smallest diameter of the rotatory motor is 1 mm and could be successfully driven.

  12. Design of decoupled dual servo stage with voice coil motor and linear motor for XY long stroke ultra-precision scanning system

    Science.gov (United States)

    Kim, Ki-Hyun; Choi, Young-Man; Gweon, Dae-Gab; Hong, Dong-Pyo; Kim, Koung-Suk; Lee, Suk-Won; Lee, Moon-Gu

    2005-12-01

    A decoupled dual servo (DDS) stage for ultra-precision scanning system is introduced in this paper. The proposed DDS consists of a 3 axis fine stage for handling and carrying workpieces and a XY coarse stage. Especially, the DDS uses three voice coil motors (VCM) as a planar actuation system of the fine stage to reduce the disturbances due to any mechanical connections with its coarse stage. VCMs are governed by Lorentz law. According to the law and its structure, there are no mechanical connections between coils and magnetic circuits. Moreover, the VCM doesn't have force ripples due to imperfections of commutation components of linear motor systems - currents and flux densities. However, due to the VCM's mechanical constraints the working range of the fine is about 5mm2. To break that hurdle, the coarse stage with linear motors is used for the fine stage to move about 200mm2. Because of the above reasons, the proposed DDS can achieve higher precision scanning than other stages with only one servo. Using MATLAB's Sequential Quadratic Programming (SQP), the VCMs are optimally designed for the highest force under conditions and constraints such as thermal dissipations due to its coil, its size, and so on. For linear motors, Halbach magnet linear motor is proposed and optimally designed in this paper. In addition, for their smooth movements without any frictions, guide systems of the DDS are composed of air bearings. And then, precisely to get their positions, linear scales with 0.1um resolution are used for the coarse's XY motions and plane mirror laser interferometers with 20nm for the fine's XYθz. On scanning, the two stages have same trajectories and are controlled. The control algorithm is Parallel method. The embodied ultra-precision scanning system has about 100nm tracking error and in-positioning stability.

  13. Mathematical Model and Computational Analysis of Selected Transient States of Cylindrical Linear Induction Motor Fed via Frequency Converter

    Directory of Open Access Journals (Sweden)

    Andrzej Rusek

    2008-01-01

    Full Text Available The mathematical model of cylindrical linear induction motor (C-LIM fed via frequency converter is presented in the paper. The model was developed in order to analyze numerically the transient states. Problems concerning dynamics of ac-machines especially linear induction motor are presented in [1 – 7]. Development of C-LIM mathematical model is based on circuit method and analogy to rotary induction motor. The analogy between both: (a stator and rotor windings of rotary induction motor and (b winding of primary part of C-LIM (inductor and closed current circuits in external secondary part of C-LIM (race is taken into consideration. The equations of C-LIM mathematical model are presented as matrix together with equations expressing each vector separately. A computational analysis of selected transient states of C-LIM fed via frequency converter is presented in the paper. Two typical examples of C-LIM operation are considered for the analysis: (a starting the motor at various static loads and various synchronous velocities and (b reverse of the motor at the same operation conditions. Results of simulation are presented as transient responses including transient electromagnetic force, transient linear velocity and transient phase current.

  14. Application of the Hyper-Poisson Generalized Linear Model for Analyzing Motor Vehicle Crashes.

    Science.gov (United States)

    Khazraee, S Hadi; Sáez-Castillo, Antonio Jose; Geedipally, Srinivas Reddy; Lord, Dominique

    2015-05-01

    The hyper-Poisson distribution can handle both over- and underdispersion, and its generalized linear model formulation allows the dispersion of the distribution to be observation-specific and dependent on model covariates. This study's objective is to examine the potential applicability of a newly proposed generalized linear model framework for the hyper-Poisson distribution in analyzing motor vehicle crash count data. The hyper-Poisson generalized linear model was first fitted to intersection crash data from Toronto, characterized by overdispersion, and then to crash data from railway-highway crossings in Korea, characterized by underdispersion. The results of this study are promising. When fitted to the Toronto data set, the goodness-of-fit measures indicated that the hyper-Poisson model with a variable dispersion parameter provided a statistical fit as good as the traditional negative binomial model. The hyper-Poisson model was also successful in handling the underdispersed data from Korea; the model performed as well as the gamma probability model and the Conway-Maxwell-Poisson model previously developed for the same data set. The advantages of the hyper-Poisson model studied in this article are noteworthy. Unlike the negative binomial model, which has difficulties in handling underdispersed data, the hyper-Poisson model can handle both over- and underdispersed crash data. Although not a major issue for the Conway-Maxwell-Poisson model, the effect of each variable on the expected mean of crashes is easily interpretable in the case of this new model. © 2014 Society for Risk Analysis.

  15. Linear methods for reducing EMG contamination in peripheral nerve motor decodes.

    Science.gov (United States)

    Kagan, Zachary B; Wendelken, Suzanne; Page, David M; Davis, Tyler; Hutchinson, Douglas T; Clark, Gregory A; Warren, David J

    2016-08-01

    Signals recorded from the peripheral nervous system (PNS) with high channel count penetrating microelectrode arrays, such as the Utah Slanted Electrode Array (USEA), often have electromyographic (EMG) signals contaminating the neural signal. This common-mode signal source may prevent single neural units from successfully being detected, thus hindering motor decode algorithms. Reducing this EMG contamination may lead to more accurate motor decode performance. A virtual reference (VR), created by a weighted linear combination of signals from a subset of all available channels, can be used to reduce this EMG contamination. Four methods of determining individual channel weights and six different methods of selecting subsets of channels were investigated (24 different VR types in total). The methods of determining individual channel weights were equal weighting, regression-based weighting, and two different proximity-based weightings. The subsets of channels were selected by a radius-based criteria, such that a channel was included if it was within a particular radius of inclusion from the target channel. These six radii of inclusion were 1.5, 2.9, 3.2, 5, 8.4, and 12.8 electrode-distances; the 12.8 electrode radius includes all USEA electrodes. We found that application of a VR improves the detectability of neural events via increasing the SNR, but we found no statistically meaningful difference amongst the VR types we examined. The computational complexity of implementation varies with respect to the method of determining channel weights and the number of channels in a subset, but does not correlate with VR performance. Hence, we examined the computational costs of calculating and applying the VR and based on these criteria, we recommend an equal weighting method of assigning weights with a 3.2 electrode-distance radius of inclusion. Further, we found empirically that application of the recommended VR will require less than 1 ms for 33.3 ms of data from one USEA.

  16. Modeling and experimental analysis of the linear ultrasonic motor with in-plane bending and longitudinal mode.

    Science.gov (United States)

    Wan, Zhijian; Hu, Hong

    2014-03-01

    A novel linear ultrasonic motor based on in-plane longitudinal and bending mode vibration is presented in this paper. The stator of the motor is composed of a metal plate and eight piezoelectric ceramic patches. There are four long holes in the plate, designed for consideration of the longitudinal and bending mode coupling. The corresponding model is developed to optimize the mechanical and electrical coupling of the stator, which causes an ellipse motion at the contact tip of the stator when the composite vibrations with longitudinal and bending are excited. Its harmonic and transient responses are simulated and inspected. A prototype based on the model is fabricated and used to conduct experiments. Results show that the amplitude of the stator's contact tips is significantly increased, which helps to amplify the driving force and speed of the motor. It is therefore feasible to implement effective linear movement using the developed prototype. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Design and characterization of a microelectromechanical system electro-thermal linear motor with interlock mechanism for micro manipulators.

    Science.gov (United States)

    Hu, Tengjiang; Zhao, Yulong; Li, Xiuyuan; Zhao, You; Bai, Yingwei

    2016-03-01

    The design, fabrication, and testing of a novel electro-thermal linear motor for micro manipulators is presented in this paper. The V-shape electro-thermal actuator arrays, micro lever, micro spring, and slider are introduced. In moving operation, the linear motor can move nearly 1 mm displacement with 100 μm each step while keeping the applied voltage as low as 17 V. In holding operation, the motor can stay in one particular position without consuming energy and no creep deformation is found. Actuation force of 12.7 mN indicates the high force generation capability of the device. Experiments of lifetime show that the device can wear over two million cycles of operation. A silicon-on-insulator wafer is introduced to fabricate a high aspect ratio structure and the chip size is 8.5 mm × 8.5 mm × 0.5 mm.

  18. A square-plate piezoelectric linear motor operating in two orthogonal and isomorphic face-diagonal-bending modes.

    Science.gov (United States)

    Ci, Penghong; Chen, Zhijiang; Liu, Guoxi; Dong, Shuxiang

    2014-01-01

    We report a piezoelectric linear motor made of a single Pb(Zr,Ti)O3 square-plate, which operates in two orthogonal and isomorphic face-diagonal-bending modes to produce precision linear motion. A 15 × 15 × 2 mm prototype was fabricated, and the motor generated a driving force of up to 1.8 N and a speed of 170 mm/s under an applied voltage of 100 Vpp at the resonance frequency of 136.5 kHz. The motor shows such advantages as large driving force under relatively low driving voltage, simple structure, and stable motion because of its isomorphic face-diagonal-bending mode.

  19. Analysis and testing of a double armature brushless dc linear motor with NdFeB permanent magnets

    International Nuclear Information System (INIS)

    Filho, A.F.F.

    1998-01-01

    The use of high-energy product NdFeB permanent magnets benefits the design and features of a double armature brushless dc linear motor. As the linear motor is also slotless, its 5 mm airgap requires a source of high flux to overcome the reluctance and produce an adequate amount of force. The linear motor employs a topology that makes use of five permanent magnets to provide excitation flux. The permanent magnets are arranged in such a way that maximises the force the linear motor can deliver. The actuator produces a force up to 86.2 N at an armature current of 4.5 A. However, the topology makes the actuator prone to saturation. It affects the operation point of the permanent magnets, reduces the airgap flux density and the force, and increases flux leakage. To avoid saturation, a flux compensation scheme was conceived. The results are presented and assessed by means of finite element simulation and by experimental results that presented a good agreement. (orig.)

  20. Motor Behavior: From Telegraph Keys and Twins to Linear Slides and Stepping

    Science.gov (United States)

    Thomas, Jerry R.

    2006-01-01

    Motor behavior is a significant area of scholarship with 64 Fellows from the American Academy of Kinesiology and Physical Education engaged in that work since 1930. This paper provides a brief overview of the history of research in motor development and motor control/learning, particularly noting the contributions to scholarship of Academy…

  1. Optimized linear motor and digital PID controller setup used in Mössbauer spectrometer

    Science.gov (United States)

    Kohout, Pavel; Kouřil, Lukáš; Navařík, Jakub; Novák, Petr; Pechoušek, Jiří

    2014-10-01

    Optimization of a linear motor and digital PID controller setup used in a Mössbauer spectrometer is presented. Velocity driving system with a digital PID feedback subsystem was developed in the LabVIEW graphical environment and deployed on the sbRIO real-time hardware device (National Instruments). The most important data acquisition processes are performed as real-time deterministic tasks on an FPGA chip. Velocity transducer of a double loudspeaker type with a power amplifier circuit is driven by the system. Series of calibration measurements were proceeded to find the optimal setup of the P, I, D parameters together with velocity error signal analysis. The shape and given signal characteristics of the velocity error signal are analyzed in details. Remote applications for controlling and monitoring the PID system from computer or smart phone, respectively, were also developed. The best setup and P, I, D parameters were set and calibration spectrum of α-Fe sample with an average nonlinearity of the velocity scale below 0.08% was collected. Furthermore, the width of the spectral line below 0.30 mm/s was observed. Powerful and complex velocity driving system was designed.

  2. Sequence of oral bacterial co-adhesion and non-contact brushing

    NARCIS (Netherlands)

    van der Mei, H. C.; Rustema-Abbing, M.; Bruinsma, G. M.; Gottenbos, B.; Busscher, H. J.

    Non-contact plaque removal offers advantages in interproximal spaces, fissures, and pockets. It requires the generation of strong fluid flows and the inclusion of air bubbles to become effective. A pair of co-adhering streptococci and actinomyces has been used previously to demonstrate non-contact

  3. A study of thermal deformation in the carriage of a permanent magnet direct drive linear motor stage

    International Nuclear Information System (INIS)

    Chow, J.H.; Zhong, Z.W.; Lin, W.; Khoo, L.P.

    2012-01-01

    Carriage deformation due to temperature gradients within the materials of the carriage affects the accuracy of precision machines. This is largely due to the indeterminist temperature distribution in the carriage's material caused by the non-linearity of heat transfer. The joule heat from the motor coil forms the main heat source. When coupled with the heat loss through convection and radiation, the temperature variation in the motor's carriage also increases. In this study, the Finite Element Analysis was used together with a set of boundary conditions, which was obtained empirically, to analyze the distortion of the motor's carriage. The simulated results were compared with those obtained through experiments. The study shows that it is important to know, rather than to assume, the thermal boundary conditions of the motor's carriage of a precision machine in order to accurately estimate the thermal deformation of the carriage in precision machining. - Highlights: ► Deformation occurs in carriages which are mounted with linear motor. ► The convective coefficient, which is assumed to be 10 W mm −2 , is shown to be invalid. ► The perfect contact conductance is shown to be invalid too. ► To have an accurate thermal model, boundary conditions have to be realistic. ► Boundary conditions are the heat source, convective and conductance values.

  4. On repeated corneal applanation with the Goldmann and two non-contact tonometers.

    Science.gov (United States)

    Almubrad, Turki M; Ogbuehi, Kelechi C

    2010-03-01

    Several authors believe it is necessary to randomise the order in which contact and non-contact tonometers are used in comparison studies. This study was carried out to investigate the effect of repeated applanation on the measured intraocular pressure. One set of measurements per session was made on each of three sessions (one session per day) with the Goldmann and two non-contact tonometers (Topcon CT80 and Keeler Pulsair EasyEye), in a pre-determined order, on one randomly selected eye of 120 subjects randomised to one of two groups. For session one, only the non-contact tonometers were used to assess the intraocular pressure of both groups. For session two, either non-contact or Goldmann tonometry was performed first and this order was reversed for session 3. Average intraocular pressures were compared between sessions to determine the presence or absence of effects on the intraocular pressure caused by prior repeated applanation with the Goldmann or either one (or both) of the non-contact tonometers. Prior applanation with a non-contact tonometer did not cause a significant (p > 0.05) reduction of the mean pressure measured with either non-contact tonometer. The mean pressure was slightly but significantly (p contact tonometers in both subject groups) when non-contact tonometry was performed after Goldmann tonometry. There was no significant difference (p > 0.05) between the pressures measured with the Goldmann tonometer prior to and subsequent to non-contact tonometry, in both subject groups. A small but statistically significant reduction in the intraocular pressure was found following applanation with the Goldmann tonometer but not with either one of two non-contact tonometers.

  5. Analysis and Design of a Maglev Permanent Magnet Synchronous Linear Motor to Reduce Additional Torque in dq Current Control

    Directory of Open Access Journals (Sweden)

    Feng Xing

    2018-03-01

    Full Text Available The maglev linear motor has three degrees of motion freedom, which are respectively realized by the thrust force in the x-axis, the levitation force in the z-axis and the torque around the y-axis. Both the thrust force and levitation force can be seen as the sum of the forces on the three windings. The resultant thrust force and resultant levitation force are independently controlled by d-axis current and q-axis current respectively. Thus, the commonly used dq transformation control strategy is suitable for realizing the control of the resultant force, either thrust force and levitation force. However, the forces on the three windings also generate additional torque because they do not pass the mover mass center. To realize the maglev system high-precision control, a maglev linear motor with a new structure is proposed in this paper to decrease this torque. First, the electromagnetic model of the motor can be deduced through the Lorenz force formula. Second, the analytic method and finite element method are used to explore the reason of this additional torque and what factors affect its change trend. Furthermore, a maglev linear motor with a new structure is proposed, with two sets of 90 degrees shifted winding designed on the mover. Under such a structure, the mover position dependent periodic part of the additional torque can be offset. Finally, the theoretical analysis is validated by the simulation result that the additionally generated rotating torque can be offset with little fluctuation in the proposed new-structure maglev linear motor. Moreover, the control system is built in MATLAB/Simulink, which shows that it has small thrust ripple and high-precision performance.

  6. The development and testing of a linear induction motor being fed from the source with limited electric power

    Science.gov (United States)

    Tiunov, V. V.

    2018-02-01

    The report provides results of the research related to the tubular linear induction motors’ application. The motors’ design features, a calculation model, a description of test specimens for mining and electric power industry are introduced. The most attention is given to the single-phase motors for high voltage switches drives with the usage of inexpensive standard single-phase transformers for motors’ power supply. The method of the motor’s parameters determination, when the motor is being fed from the transformer, working in the overload mode, was described, and the results of it practical usage were good enough for the engineering practice.

  7. EEG sensorimotor rhythms' variation and functional connectivity measures during motor imagery: linear relations and classification approaches.

    Science.gov (United States)

    Stefano Filho, Carlos A; Attux, Romis; Castellano, Gabriela

    2017-01-01

    Hands motor imagery (MI) has been reported to alter synchronization patterns amongst neurons, yielding variations in the mu and beta bands' power spectral density (PSD) of the electroencephalography (EEG) signal. These alterations have been used in the field of brain-computer interfaces (BCI), in an attempt to assign distinct MI tasks to commands of such a system. Recent studies have highlighted that information may be missing if knowledge about brain functional connectivity is not considered. In this work, we modeled the brain as a graph in which each EEG electrode represents a node. Our goal was to understand if there exists any linear correlation between variations in the synchronization patterns-that is, variations in the PSD of mu and beta bands-induced by MI and alterations in the corresponding functional networks. Moreover, we (1) explored the feasibility of using functional connectivity parameters as features for a classifier in the context of an MI-BCI; (2) investigated three different types of feature selection (FS) techniques; and (3) compared our approach to a more traditional method using the signal PSD as classifier inputs. Ten healthy subjects participated in this study. We observed significant correlations ( p  < 0.05) with values ranging from 0.4 to 0.9 between PSD variations and functional network alterations for some electrodes, prominently in the beta band. The PSD method performed better for data classification, with mean accuracies of (90 ± 8)% and (87 ± 7)% for the mu and beta band, respectively, versus (83 ± 8)% and (83 ± 7)% for the same bands for the graph method. Moreover, the number of features for the graph method was considerably larger. However, results for both methods were relatively close, and even overlapped when the uncertainties of the accuracy rates were considered. Further investigation regarding a careful exploration of other graph metrics may provide better alternatives.

  8. Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

    Science.gov (United States)

    Elliott, D. G.

    1977-01-01

    Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

  9. An analytical method for the calculation of static characteristics of linear step motors for control rod drives in nuclear reactors

    International Nuclear Information System (INIS)

    Khan, S.H.; Ivanov, A.A.

    1995-01-01

    An analytical method for calculating static characteristics of linear dc step motors (LSM) is described. These multiphase passive-armature motors are now being developed for control rod drives (CRD) in large nuclear reactors. The static characteristics of such LSM is defined by the variation of electromagnetic force with armature displacement and it determines motor performance in its standing and dynamic modes of operation. The proposed analytical technique for calculating this characteristic is based on the permeance analysis method applied to phase magnetic circuits of LSM. Reluctances of various parts of phase magnetic circuit is calculated analytically by assuming probable flux paths and by taking into account complex nature of magnetic field distribution in it. For given armature positions stator and armature iron saturations are taken into account by an efficient iterative algorithm which gives fast convergence. The method is validated by comparing theoretical results with experimental ones which shows satisfactory agreement for small stator currents and weak iron saturation

  10. Evaluation of anti-tuberculosis antibodies in healthy contact and non-contacts persons

    International Nuclear Information System (INIS)

    Aziz, N; Bukhari, M.H; Muneer, M; Tayyab, M; Chaudhry, N.A.

    2006-01-01

    This study was conducted to see the presence of the antimycobacterial antibodies in healthy household contacts of tuberculosis patients and healthy normal subjects who have never been in contact with tuberculosis patients. A total of 200 subjects, 120 with history of household contact and 80 without such history were included in the study. Routine Haematological investigations were performed and all the sera of 200 subjects were tested who 19M, 19G and IgA anti tuberculosis antibodies using ELISA technique. There was no difference in the average age of the household contacts and non-contacts. The complaints of pyrexia, night sweats and loss of weight was more in house hold contacts as compared to non-contacts. The awareness about BCG vaccination was equal among the household contacts and non-contacts. The combined serological positivity of the household contacts was 65.8% and the combined serological positivity for non-contacts was 34.1%. There was no statistically significant difference in the presence of 19M among household contacts as compared to non-contacts. However both IgG and 19A were present in significantly higher number of household contacts as compared to non contacts. This study concludes that the persons living in the house with a patient suffering from active pulmonary tuberculosis (household contact) have more chances of being infected with Mycobacterium tuberculosis as compared to the healthy non-contacts. (author)

  11. Development of Propulsion Inverter Control System for High-Speed Maglev based on Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Jeong-Min Jo

    2017-02-01

    Full Text Available In the case of a long-stator linear drive, unlike rotative drives for which speed or position sensors are a single unit attached to the shaft, these sensors extend along the guideway. The position signals transmitted from a maglev vehicle cannot meet the need of the real-time propulsion control in the on-ground inverter power substations. In this paper the design of the propulsion inverter control system with a position estimator for driving a long-stator synchronous motor in a high-speed maglev train is proposed. The experiments have been carried out at the 150 m long guideway at the O-song test track. To investigate the performance of the position estimator, the propulsion control system with, and without, the position estimator are compared. The result confirms that the proposed strategy can meet the dynamic property needs of the propulsion inverter control system for driving long-stator linear synchronous motors.

  12. Simplified 3D Finite Element Analysis of Linear Inductor Motor for Integrated Magnetic Suspension/Propulsion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sang Sub; Jang Seok Myeong [Chungnam National University(Korea)

    2000-06-01

    The 4-pole linear homopolar synchronous motor (LHSM), so called linear inductor motor, is composed of the figure-of-eight shaped 3-phase armature windings, DC field windings, and the segmented secondary with the transverse bar track. To reduce the calculation time, the simplified 3D finite element model with equivalent reluctance and/or permanent magnet is presented. To obtain a clear understanding, propriety and usefulness of the developed mode., we compare with the results of simplified 3D FEA and test. Consequently, the results of simplified and 3D FEM analysis are nearly identical, but much larger than that of static test at d-axis armature excitation. Therefore the improved FEA model, such as full model with half slot, is needed for the precise analysis. (author). refs., figs., tabs.

  13. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion.

    Science.gov (United States)

    Lee, Dong-Jin; Lee, Sun-Kyu

    2015-01-01

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  14. H-Shaped Multiple Linear Motor Drive Platform Control System Design Based on an Inverse System Method

    Directory of Open Access Journals (Sweden)

    Caiyan Qin

    2017-12-01

    Full Text Available Due to its simple mechanical structure and high motion stability, the H-shaped platform has been increasingly widely used in precision measuring, numerical control machining and semiconductor packaging equipment, etc. The H-shaped platform is normally driven by multiple (three permanent magnet synchronous linear motors. The main challenges for H-shaped platform-control include synchronous control between the two linear motors in the Y direction as well as total positioning error of the platform mover, a combination of position deviation in X and Y directions. To deal with the above challenges, this paper proposes a control strategy based on the inverse system method through state feedback and dynamic decoupling of the thrust force. First, mechanical dynamics equations have been deduced through the analysis of system coupling based on the platform structure. Second, the mathematical model of the linear motors and the relevant coordinate transformation between dq-axis currents and ABC-phase currents are analyzed. Third, after the main concept of inverse system method being explained, the inverse system model of the platform control system has been designed after defining relevant system variables. Inverse system model compensates the original nonlinear coupled system into pseudo-linear decoupled linear system, for which typical linear control methods, like PID, can be adopted to control the system. The simulation model of the control system is built in MATLAB/Simulink and the simulation result shows that the designed control system has both small synchronous deviation and small total trajectory tracking error. Furthermore, the control program has been run on NI controller for both fixed-loop-time and free-loop-time modes, and the test result shows that the average loop computation time needed is rather small, which makes it suitable for real industrial applications. Overall, it proves that the proposed new control strategy can be used in

  15. [Correlation between Goldmann and non-contact tonometry based on corneal thickness].

    Science.gov (United States)

    Schepens, G; Urier, N; Bechetoille, A; De Potter, P

    2001-01-01

    In this transversal study, we measure the intra ocular pressure by means of the Goldmann tonometer and a Non-Contact tonometer along with the central cornea thickness in 136 eyes of 73 patients. The statistical analysis of the collected data doesn't allow us to establish a correlation between the variation of the corneal thickness and the difference between the Goldmann tonometer and Non-Contact tonometer measures. The relative precision of the Non-Contact tonometer compared with the Goldmann tonometer doesn't seem influenced by the central cornea thickness.

  16. METHOD OF NON-CONTACT PHOTOLUMINESCENT DIAGNOSTICS OF THE EYE FIBROUS TUNIC CONDITION

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2018-01-01

    Full Text Available Non-contact optical diagnostics of structural disorders of the eye has a number of advantages: high speed, accuracy and a large range of parameters available for analysis. The paper presents the results of studies of the photoluminescence of the fibrous tunic of the eye, excited by polarized light, depending on the intraocular pressure. In the experiments, isolated de-epithelized eyes of the rabbit were used, inside of which pressure up to 50 mm Hg was artificially created. Under these conditions, the cornea and sclera were illuminated with linearly polarized light at wavelengths of 250, 350 and 450 nm, exciting photoluminescence in the wavelength range up to 700 nm. Cross and co-polarized photoluminescence spectra excited by linearly polarized light were obtained. It has been established that, when excited by polarized light, the photoluminescence of the cornea is partially polarized. Depending on the wavelength of the photoluminescence, the degree of polarization varies from 0.2 to 0.35. It is shown that the degree of polarization of the photoluminescence of the cornea of the eye upon excitation by linearly polarized light can be used as a measurable parameter for assessing the physiological state of the eye. It is shown that the photoluminescence spectrum consists of two bands with maxima near 460-470 and 430-440 nm. These bands are assigned, respectively, to pyridinnucleotides and glycosylated collagen. A significant contribution can be made by the epithelium of the eye, which contains riboflavin with characteristic absorption bands near 450 and 365 nm. When excited at 450 nm, the photoluminescence maximum is located near 540 nm, which corresponds to the spectrum of fluorophores in the endothelium and epithelium. The spectrum of photoluminescence upon excitation at a wavelength of 250 nm can be attributed to tryptophan located in the intraocular lens.

  17. Vibration Analysis and Experimental Research of the Linear-Motor-Driven Water Piston Pump Used in the Naval Ship

    Directory of Open Access Journals (Sweden)

    Ye-qing Huang

    2016-01-01

    Full Text Available Aiming at the existing problems of traditional water piston pump used in the naval ship, such as low efficiency, high noise, large vibration, and nonintelligent control, a new type of linear-motor-driven water piston pump is developed and its vibration characteristics are analyzed in this research. Based on the 3D model of the structure, the simulation analyses including static stress analysis, modal analysis, and harmonic response analysis are conducted. The simulation results reveal that the mode shape under low frequency stage is mainly associated with the eccentricity swing of the piston rod. The vibration experiment results show that the resonance frequency of linear-motor-driven water piston pump is concentrated upon 500 Hz and 800 Hz in the low frequency range. The dampers can change the resonance frequency of the system to a certain extent. The vibration under triangular motion curve is much better than that of S curve, which is consistent with the simulation conclusion. This research provides an effective method to detect the vibration characteristics and a reference for design and optimization of the linear-motor-driven water piston pump.

  18. Intelligent measurement and compensation of linear motor force ripple: a projection-based learning approach in the presence of noise

    Science.gov (United States)

    Liu, Yang; Song, Fazhi; Yang, Xiaofeng; Dong, Yue; Tan, Jiubin

    2018-06-01

    Due to their structural simplicity, linear motors are increasingly receiving attention for use in high velocity and high precision applications. The force ripple, as a space-periodic disturbance, however, would deteriorate the achievable dynamic performance. Conventional force ripple measurement approaches are time-consuming and have high requirements on the experimental conditions. In this paper, a novel learning identification algorithm is proposed for force ripple intelligent measurement and compensation. Existing identification schemes always use all the error signals to update the parameters in the force ripple. However, the error induced by noise is non-effective for force ripple identification, and even deteriorates the identification process. In this paper only the most pertinent information in the error signal is utilized for force ripple identification. Firstly, the effective error signals caused by the reference trajectory and the force ripple are extracted by projecting the overall error signals onto a subspace spanned by the physical model of the linear motor as well as the sinusoidal model of the force ripple. The time delay in the linear motor is compensated in the basis functions. Then, a data-driven approach is proposed to design the learning gain. It balances the trade-off between convergence speed and robustness against noise. Simulation and experimental results validate the proposed method and confirm its effectiveness and superiority.

  19. Use of non-contacting electromagnetic inductive method for estimating soil moisture across a landscape

    International Nuclear Information System (INIS)

    Khakural, B.R.; Robert, P.C.; Hugins, D.R.

    1998-01-01

    There is a growing interest in real-time estimation of soil moisture for site-specific crop management. Non-contacting electromagnetic inductive (EMI) methods have potentials to provide real-time estimate of soil profile water contents. Soil profile water contents were monitored with a neutron probe at selected sites. A Geonics LTD EM-38 terrain meter was used to record bulk soil electrical conductivity (EC(A)) readings across a soil-landscape in West central Minnesota with variable moisture regimes. The relationships among EC(A), selected soil and landscape properties were examined. Bulk soil electrical conductivity (0-1.0 and 0-0.5 m) was negatively correlated with relative elevation. It was positively correlated with soil profile (1.0 m) clay content and negatively correlated with soil profile coarse fragments (2 mm) and sand content. There was significant linear relationship between ECA (0-1.0 and 0-0.5) and soil profile water storage. Soil water storage estimated from ECA reflected changes in landscape and soil characteristics

  20. Clinical comparison of the XPERT non-contact tonometer and the conventional Goldmann applanation tonometer.

    Science.gov (United States)

    Hansen, M K

    1995-04-01

    Intraocular pressure (IOP) in the right eye of 113 patients was measured with one XPERT NCT air-puff non-contact tonometer (XPERT) and compared with IOP measured with one Goldmann applanation tonometer (GAT). Precision of the methods was judged by variance analysis, indicating that GAT was slightly more precise than XPERT. The slope of the linear relationship between the methods did not differ significantly from 1.0. Mean difference between the methods was 0.92 mmHg, XPERT measuring lower than GAT, p = 0.00017. The intra-individual difference between methods ranged from -8.00 to 8.67 mmHg, and standard deviation (SD) of differences was 2.52 mmHg. The 95% limits of agreement between the two methods were -5.85 to 4.01 mmHg. The SD of differences is of approximately the same size as previous XPERT vs GAT as well as previous GAT vs GAT studies.

  1. Inhibition linearizes firing rate responses in human motor units: implications for the role of persistent inward currents.

    Science.gov (United States)

    Revill, Ann L; Fuglevand, Andrew J

    2017-01-01

    Motor neurons are the output neurons of the central nervous system and are responsible for controlling muscle contraction. When initially activated during voluntary contraction, firing rates of motor neurons increase steeply but then level out at modest rates. Activation of an intrinsic source of excitatory current at recruitment onset may underlie the initial steep increase in firing rate in motor neurons. We attempted to disable this intrinsic excitatory current by artificially activating an inhibitory reflex. When motor neuron activity was recorded while the inhibitory reflex was engaged, firing rates no longer increased steeply, suggesting that the intrinsic excitatory current was probably responsible for the initial sharp rise in motor neuron firing rate. During graded isometric contractions, motor unit (MU) firing rates increase steeply upon recruitment but then level off at modest rates even though muscle force continues to increase. The mechanisms underlying such firing behaviour are not known although activation of persistent inward currents (PICs) might be involved. PICs are intrinsic, voltage-dependent currents that activate strongly when motor neurons (MNs) are first recruited. Such activation might cause a sharp escalation in depolarizing current and underlie the steep initial rise in MU firing rate. Because PICs can be disabled with synaptic inhibition, we hypothesized that artificial activation of an inhibitory pathway might curb this initial steep rise in firing rate. To test this, human subjects performed slow triangular ramp contractions of the ankle dorsiflexors in the absence and presence of tonic synaptic inhibition delivered to tibialis anterior (TA) MNs by sural nerve stimulation. Firing rate profiles (expressed as a function of contraction force) of TA MUs recorded during these tasks were compared for control and stimulation conditions. Under control conditions, during the ascending phase of the triangular contractions, 93% of the firing

  2. INNOVATIVE NON-CONTACT METROLOGY SOLUTIONS FOR LARGE OPTICAL TELESCOPES, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has unique non-contact precision metrology requirements for dimensionally inspecting the global position and orientation of large and highly-polished...

  3. ChemCam-like Spectrometer for Non-Contact Measurements of Key Isotopes, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This project addresses the need for a non-contact instrument capable of measuring the isotopic ratios O-18/O-16 and D/H from water ice and other solid materials...

  4. Freeform optics: a non-contact "test plate" for manufacturing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this NASA SBIR Phase I study is to determine the feasibility of measuring precision (fractional wave) freeform optics using non-contact areal (imaging)...

  5. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping.

    Science.gov (United States)

    Schumacher, Christian; Seyfarth, André

    2017-01-01

    In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB), velocity (VFB) and force feedback (FFB) pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort). Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map . The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency). Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length) or environmental parameters (ground compliance). Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a specific

  6. A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint.

    Science.gov (United States)

    Li, Xiaoniu; Yao, Zhiyuan; Yang, Mojian

    2017-06-01

    A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint is proposed in this paper. The motor is comprised of a V-shaped transducer, a slider, a clamp, and a base. The V-shaped transducer consists of two piezoelectric beams connected through a flexible joint to form an appropriate coupling angle. The V-shaped motor is operated in the coupled longitudinal-bending mode. Longitudinal and bending movements are transferred by the flexible joint between the two beams. Compared with the coupled longitudinal-bending mode of the single piezoelectric beam or the symmetrical and asymmetrical modes of the previous V-shaped transducer, the coupled longitudinal-bending mode of the V-shaped transducer with a flexible joint provides higher vibration efficiency and more convenient mode conformance adjustment. A finite element model of the V-shaped transducer is created to numerically study the influence of geometrical parameters and to determine the final geometrical parameters. In this paper, three prototypes were then fabricated and experimentally investigated. The modal test results match well with the finite element analysis. The motor mechanical output characteristics of three different coupling angles θ indicate that V-90 (θ = 90°) is the optimal angle. The mechanical output experiments conducted using the V-90 prototype (Size: 59.4 mm × 30.7 mm × 4 mm) demonstrate that the maximum unloaded speed is 1.2 m/s under a voltage of 350 Vpp, and the maximum output force is 15 N under a voltage of 300 Vpp. The proposed novel V-shaped linear ultrasonic motor has a compact size and a simple structure with a large thrust-weight ratio (0.75 N/g) and high speed.

  7. Design of a Control System for a Maglev Planar Motor Based on Two-Dimension Linear Interpolation

    Directory of Open Access Journals (Sweden)

    Feng Xing

    2017-08-01

    Full Text Available In order to realize the high speed and high-precision control of a maglev planar motor, a high-precision electromagnetic model is needed in the first place, which can also contribute to meeting the real-time running requirements. Traditionally, the electromagnetic model is based on analytical calculations. However, this neglects the model simplification and the manufacturing errors, which may bring certain errors to the model. Aiming to handle this inaccuracy, this paper proposes a novel design method for a maglev planar motor control system based on two-dimensional linear interpolation. First, the magnetic field is divided into several regions according to the symmetry of the Halbach magnetic array, and the uniform grid method is adopted to partition one of these regions. Second, targeting this region, it is possible to sample the electromagnetic forces and torques on each node of the grid and obtain the complete electromagnetic model in this region through the two-dimensional linear interpolation method. Third, the whole electromagnetic model of the maglev planar motor can be derived according to the symmetry of the magnetic field. Finally, the decoupling method and controller are designed according to this electromagnetic model, and thereafter, the control model can be established. The designed control system is demonstrated through simulations and experiments to feature better accuracy and meet the requirements of real-time control.

  8. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping

    Directory of Open Access Journals (Sweden)

    Christian Schumacher

    2017-11-01

    Full Text Available In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB, velocity (VFB and force feedback (FFB pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort. Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map. The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency. Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length or environmental parameters (ground compliance. Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a

  9. Linear versus non-linear measures of temporal variability in finger tapping and their relation to performance on open- versus closed-loop motor tasks: comparing standard deviations to Lyapunov exponents.

    Science.gov (United States)

    Christman, Stephen D; Weaver, Ryan

    2008-05-01

    The nature of temporal variability during speeded finger tapping was examined using linear (standard deviation) and non-linear (Lyapunov exponent) measures. Experiment 1 found that right hand tapping was characterised by lower amounts of both linear and non-linear measures of variability than left hand tapping, and that linear and non-linear measures of variability were often negatively correlated with one another. Experiment 2 found that increased non-linear variability was associated with relatively enhanced performance on a closed-loop motor task (mirror tracing) and relatively impaired performance on an open-loop motor task (pointing in a dark room), especially for left hand performance. The potential uses and significance of measures of non-linear variability are discussed.

  10. A Comparison of Cognitive Function in Former Rugby Union Players Compared with Former Non-Contact-Sport Players and the Impact of Concussion History.

    Science.gov (United States)

    Hume, Patria A; Theadom, Alice; Lewis, Gwyn N; Quarrie, Kenneth L; Brown, Scott R; Hill, Rosamund; Marshall, Stephen W

    2017-06-01

    This study investigated differences in cognitive function between former rugby and non-contact-sport players, and assessed the association between concussion history and cognitive function. Overall, 366 former players (mean ± standard deviation [SD] age 43.3 ± 8.2 years) were recruited from October 2012 to April 2014. Engagement in sport, general health, sports injuries and concussion history, and demographic information were obtained from an online self-report questionnaire. Cognitive functioning was assessed using the online CNS Vital Signs neuropsychological test battery. Cohen's d effect size statistics were calculated for comparisons across player groups, concussion groups (one or more self-reported concussions versus no concussions) and between those groups with CNS Vital Signs age-matched norms (US norms). Individual differences within groups were represented as SDs. The elite-rugby group (n = 103) performed worse on tests of complex attention, processing speed, executive functioning, and cognitive flexibility than the non-contact-sport group (n = 65), and worse than the community-rugby group (n = 193) on complex attention. The community-rugby group performed worse than the non-contact group on executive functioning and cognitive flexibility. Compared with US norms, all three former player groups performed worse on verbal memory and reaction time; rugby groups performed worse on processing speed, cognitive flexibility and executive functioning; and the community-rugby group performed worse on composite memory. The community-rugby group and non-contact-sport group performed slightly better than US norms on complex attention, as did the elite-rugby group for motor speed. All three player groups had greater individual differences than US norms on composite memory, verbal memory and reaction time. The elite-rugby group had greater individual differences on processing speed and complex attention, and the community-rugby group had greater individual

  11. Calculation of static characteristics of linear step motors for control rod drives of nuclear reactors - an approximate approach

    International Nuclear Information System (INIS)

    Khan, S.H.; Ivanov, A.A.

    1993-01-01

    This paper describes an approximate method for calculating the static characteristics of linear step motors (LSM), being developed for control rod drives (CRD) in large nuclear reactors. The static characteristic of such an LSM which is given by the variation of electromagnetic force with armature displacement determines the motor performance in its standing and dynamic modes. The approximate method of calculation of these characteristics is based on the permeance analysis method applied to the phase magnetic circuit of LSM. This is a simple, fast and efficient analytical approach which gives satisfactory results for small stator currents and weak iron saturation, typical to the standing mode of operation of LSM. The method is validated by comparing theoretical results with experimental ones. (Author)

  12. MODELING OF OPERATION OF COAXIAL-LINEAR MOTORS WITH AXIAL AND RADIAL DIRECTIONS OF MAGNETIZATION OF PERMANENT MAGNETS IN DYNAMIC MODE

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-12-01

    Full Text Available Theoretical and experimental investigations of the amplitude, phase and inertia-power frequency characteristics of two types of coaxial-linear electric motors of back-and-forth motion with permanent magnets, which magnetization vector is directed axially and radially relative to the axis of the runner are carried out. The comparative analysis of characteristics of these motors is presented.

  13. Non Linear, Time Variant Speed Control of a Single Phase Hybrid Switched Reluctance Motor

    DEFF Research Database (Denmark)

    Jakobsen, Uffe; Ahn, Jin Woo

    2009-01-01

    A high torque ripple in a given motor always presents a challenge for the speed control, since this ripple may lead to excessive actuation and ultimately may even lead to instability. The conventional solution is to low pass filter the measured speed, but this lowers dynamic control performance...

  14. Non-contact magnetic coupled power and data transferring system for an electric vehicle

    International Nuclear Information System (INIS)

    Matsuda, Y.; Sakamoto, H.

    2007-01-01

    We have developed a system which transmits electric power and communication data simultaneously in a non-contact method using a magnetic coupling coil. Already, we are developing the fundamental technology of a non-contact charging system, and this is applied in electric shavers, electric toothbrushes, etc. Moreover, basic experiments are being conducted for applying this non-contact charging system to electric equipments such as an electric vehicle (EV), which is a zero emission vehicle and environmentally excellent and will be the transportation means of the next generation. The technology can also be applied in other electronic equipment, etc. However, since the power supply route for these individual devices is independent, the supply system is complicated. EV also has to perform the transmission of electric power and the transmission of information (data), such as the amount of the charge, in a separate system, and thus is quite complicated. In this study, by performing simultaneously the transmission of electric power and information (data) using magnetic coupling technology in which it does not contact, the basic experiment aimed at attaining and making unification of a system simple was conducted, and the following good results were obtained: (1) Electric power required for load can be transmitted easily by non-contact. (2) A signal can easily be transmitted bidirectionally by non-contact. (3) This system is reliable, and is widely applicable

  15. Development of a high cycle vibration fatigue diagnostic system with non-contact vibration sensing

    International Nuclear Information System (INIS)

    Nekomoto, Yoshitsugu; Tanaka, Masanori; Nishimura, Moritatsu; Matsumoto, Kenji; O'shima, Eiji

    2004-01-01

    Nuclear power plants have a large number of pipes. These small-diameter pipe branches in particles are often damaged due to high-cycle fatigue. In order to ensure the reliability of a plant it is important to detect fatigue damages in pipe branches at an early stage and to develop the technology to predict and diagnose the advancement of fatigue. Further, in order to carry out the diagnosis of the piping system effectively during operation, non-contact evaluation is useful. Hence, we have developed a ''high-cycle fatigue diagnostic system with non-contact vibration sensing'', which measures the vibration of the pipe branch using a non-contact sensor. (author)

  16. The Transfer efficiency analysis and modeling technology of new non - contact power transmission equipment

    Directory of Open Access Journals (Sweden)

    Cao Shi

    2017-01-01

    Full Text Available Due to the shortcomings of current power transmission which is used in ultrasound - assisted machining and the different transfer efficiency caused by the related parameters of the electromagnetic converter, this paper proposes an analysis model of the new non-contact power transmission device with more stable output and higher transmission efficiency. Then By utilizing Maxwell finite element analysis software, this paper studies the law of the transfer efficiency of the new non-contact transformer and compares new type with traditional type with the method of setting the boundary conditions of non-contact power supply device. At last, combining with the practical application, the relevant requirements which have a certain reference value in the application are put forward in the actual processing.

  17. Non-contact optoacoustic imaging with focused air-coupled transducers

    Energy Technology Data Exchange (ETDEWEB)

    Deán-Ben, X. Luís [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); Pang, Genny A.; Razansky, Daniel, E-mail: dr@tum.de [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); School of Medicine, Technische Universität München (TUM), Munich (Germany); Montero de Espinosa, Francisco [CSIC, Institute of Physics and Communication Technologies, Madrid (Spain)

    2015-08-03

    Non-contact optoacoustic imaging employing raster-scanning of a spherically focused air-coupled ultrasound transducer is showcased herein. Optoacoustic excitation with laser fluence within the maximal permissible human exposure limits in the visible and near-infrared spectra is applied to objects with characteristic dimensions smaller than 1 mm and absorption properties representative of the whole blood at near-infrared wavelengths, and these signals are shown to be detectable without contact to the sample using an air-coupled transducer with reasonable signal averaging. Optoacoustic images of vessel-mimicking tubes embedded in an agar phantom captured with this non-contact sensing technique are also showcased. These initial results indicate that an air-coupled ultrasound detection approach can be suitable for non-contact biomedical imaging with optoacoustics.

  18. Development of a high cycle vibration fatigue diagnostic system with non-contact vibration sensing

    International Nuclear Information System (INIS)

    Yoshitsugu, Nekomoto; Satoshi, Kiriyama; Moritatsu, Nishimura; Kenji, Matsumoto; Eiji, O'shima

    2001-01-01

    Nuclear power plants have a large number of pipes. Of these small-diameter pipe branches in particular are often damaged due to high-cycle fatigue. In order to ensure the reliability of a plant it is important to detect the fatigues in pipe branches at an early stage and to develop the technology to predict and diagnose the advancement of fatigue. Further, in order to carry out the diagnosis of the piping system effectively during operation, non-contact evaluation is useful. Hence, we have developed a 'high-cycle fatigue diagnostic system with non-contact vibration sensing', where the vibration of the pipe branch is measured using a non-contact sensor. Since the contents of the developed sensor technology has already been reported, this paper mainly describes the newly developed high-cycle fatigue diagnostic system. (authors)

  19. The non-contact biometric identified bio signal measurement sensor and algorithms.

    Science.gov (United States)

    Kim, Chan-Il; Lee, Jong-Ha

    2018-04-25

    In these days, wearable devices have been developed for effectively measuring biological data. However, these devices have tissue allege and noise problem. To solve these problems, biometric measurement based on a non-contact method, such as face image sequencing is developed. This makes it possible to measure biometric data without any operation and side effects. However, it is impossible for a remote center to identify the person whose data are measured by the novel methods. In this paper, we propose the novel non-contact heart rate and blood pressure imaging system, Deep Health Eye. This system has authentication process at the same time as measuring bio signals, through non-contact method. In the future, this system can be convenient home bio signal monitoring system by combined with smart mirror.

  20. Speed control of permanent magnet excitation transverse flux linear motor by using adaptive neuro-fuzzy controller

    Energy Technology Data Exchange (ETDEWEB)

    Hasanien, Hany M., E-mail: Hanyhasanien@ieee.or [Dept. of Elec. Power and Machines, Faculty of Eng., Ain-shams Univ. Cairo (Egypt); Muyeen, S.M. [Department of Electrical Engineering, Petroleum Institute, Abu Dhabi (United Arab Emirates); Tamura, Junji [Department of EEE, Kitami Institute of Technology, 165 Koen Cho, Kitami 090-8507, Hokkaido (Japan)

    2010-12-15

    This paper presents a novel adaptive neuro-fuzzy controller applies on transverse flux linear motor for controlling its speed. The proposed controller presents fuzzy logic controller with self tuning scaling factors based on artificial neural network structure. It has two input variables and one control output variable. Firstly the fuzzy logic control rules are described then NN architecture is represented to self tune the output scaling factors of the controller. The application of this control technique represents the novelty of work, where this algorithm has so far not been stated before for this type of drives. This methodology solves the problem of nonlinearities and load changes of TFLM drives. The dynamic response of the motor is studied under the rated load condition as well as load disturbances. The proposed controller ensures fast and accurate dynamic response with an excellent steady state performance. The dynamic response of the motor with the proposed controller is compared with PI and adaptive NN controllers. It is found that the proposed controller gives better and faster response from the viewpoint of overshoot and settling time. Matlab/Simulink tool is used for this dynamic simulation study.

  1. Lift force fluctuations of magnetically levitated vehicles with an integrated synchronous linear motor and their significance for the technical security

    Energy Technology Data Exchange (ETDEWEB)

    Mnich, P; Huebner, K D

    1980-07-15

    In this paper the influence of the motor current on the magnetic force is investigated by an analytical method. With the integrated synchronous linear motor the reactions of the current sheet on the excitation field are depending on the pole angle and the amplitude of the current sheet. For an undisturbed operation - current sheet and induction wave in phase - the influence of the motor current on the magnetic force can be neglected. In case of a disturbed performance, i.e. when the pole angle is changing periodically, fluctuations of the magnetic force will be found. This effect has to be compensated by a reserve magnetic force in the levitation control. With the technical data for the new magnetic levitation pilots plants (International Traffic Fair 1979 at Hamburg and Transrapid - Pilot Plant Emsland) the stated relations are evaluated. Approximated relations for the levitation force are derived. For comparison, a finite-difference computer programme from the 'Institut fuer elektrische Maschinen, Antriebe und Bahnen, Technische Universitaet Braunschweig' is applied. The approximated relations developed in this paper are verified - with a sufficient precision - by the numerical calculations.

  2. Bio-inspired piezoelectric linear motor driven by a single-phase harmonic wave with an asymmetric stator.

    Science.gov (United States)

    Pan, Qiaosheng; Miao, Enming; Wu, Bingxuan; Chen, Weikang; Lei, Xiujun; He, Liangguo

    2017-07-01

    A novel, bio-inspired, single-phase driven piezoelectric linear motor (PLM) using an asymmetric stator was designed, fabricated, and tested to avoid mode degeneracy and to simplify the drive mechanism of a piezoelectric motor. A piezoelectric transducer composed of two piezoelectric stacks and a displacement amplifier was used as the driving element of the PLM. Two simple and specially designed claws performed elliptical motion. A numerical simulation was performed to design the stator and determine the feasibility of the design mechanism of the PLM. Moreover, an experimental setup was built to validate the working principles, as well as to evaluate the performance, of the PLM. The prototype motor outputs a no-load speed of 233.7 mm/s at a voltage of 180 V p-p and a maximum thrust force of 2.3 N under a preload of 10 N. This study verified the feasibility of the proposed design and provided a method to simplify the driving harmonic signal and structure of PLMs.

  3. Optimal design of a double-sided linear motor with a multi-segmented trapezoidal magnet array for a high precision positioning system

    International Nuclear Information System (INIS)

    Lee, Moon G.; Gweon, Dae-Gab

    2004-01-01

    A comparative analysis is performed for linear motors adopting conventional and multi-segmented trapezoidal (MST) magnet arrays, respectively, for a high-precision positioning system. The proposed MST magnet array is a modified version of a Halbach magnet array. The MST array has trapezoidal magnets with variable shape and dimensions while the Halbach magnet array generally has a rectangular magnet with identical dimensions. We propose a new model that can describe the magnetic field resulting from the complex-shaped magnets. The model can be applied to both MST and conventional magnet arrays. Using the model, a design optimization of the two types of linear motors is performed and compared. The magnet array with trapezoidal magnets can produce more force than one with rectangular magnets when they are arrayed in a linear motor where there is a yoke with high permeability. After the optimization and comparison, we conclude that the linear motor with the MST magnet array can generate more actuating force per volume than the motor with the conventional array. In order to satisfy the requirements of next generation systems such as high resolution, high speed, and long stroke, the use of a linear motor with a MST array as an actuator in a high precision positioning system is recommended from the results obtained here

  4. MODELING OF EQUIVALENT STIFFNESS OF A MAGNETIC SPRING OF VIBRATION EXCITER BASED ON COAXIAL-LINEAR MOTOR

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2015-12-01

    Full Text Available Purpose. The research of the influence of value and direction of current on the equivalent spring magnetic force based on coaxial-linear motor (CLM – MS. Methodology. We carried out investigation of the equivalent harshness of magnetic spring with determination of electromechanical propulsion performance characteristics by the methods of computer modeling and experimental research of physical model of CLM – MS. The modeling of magnetic spring of CLM – MS is carried out by the finite-element method. The challenge is met as an axisymmetric challenge in cylindrical co-ordinates in magnetostatic approach. The experimental investigattion of the propulsion performance characteristics of magnetic spring is carried out on the test bench. Results. After the computer modeling and the experimental investigation of the electromechanical propulsion performance characteristics of magnetic spring the expressions of equivalent stiffness coefficient depending on the current in winding are obtained. The results of computer modeling are confirmed experimentally. Originality. The determination of equivalent stiffness coefficient of magnetic spring of vibration exciter based on coaxial-linear motor. Practical value. The obtained determination of equivalent stiffness coefficient of magnetic spring may be used in process of designing of vibration machines with devices for change of natural oscillation frequency.

  5. Application and development of non contact angle-wide viewing system in vitreous retinal surgery

    Directory of Open Access Journals (Sweden)

    Rong-Hua He

    2016-07-01

    Full Text Available Wide-angle viewing system as an important auxiliary device can clearly observe the whole fundus field of vision in vitreous surgery, which enable vitreoretinal surgery more efficient, safer and more effective. So it has very high application value in ophthalmologic operation. In this paper, we studied the development and application of wide-angle viewing system in vitreoretinal surgery in recent years, from which we summed up the advantage of non-contact wide-angle viewing system in clinical field, and pointed out the shortcomings. The ultimate goal is to make the non-contact wide-angle viewing system better applied in vitreous surgery.

  6. Dynamic contour tonometry vs. non-contact tonometry and their relation with corneal thickness

    OpenAIRE

    Briceño, Adriana; Mas, David; Domenech, Begoña

    2016-01-01

    The purpose of this study is to evaluate the concordance between intraocular pressure (IOP) values obtained with a dynamic contour tonometer (DCT) and a non-contact tonometer (NCT) in healthy patients and to investigate the effect of central corneal thickness (CCT) on IOP readings for each of the two measuring systems. The mean IOP yielded by DCT, NCT and corrected non-contact tonometer (CNCT) was 17.1 mmHg, 15.5 mmHg and 12.2 mmHg, respectively. The average CCT was 563.6 μm and the ocular pu...

  7. Comparative study of three non-contact tonometers and the Goldmann tonometer.

    Science.gov (United States)

    Moreno-Montañés, J; Gómez-Demmel, E; Lajara-Blesa, J; Aliseda-Pérez de Madrid, D

    1994-01-01

    The main objective of this study was to find out how well three non-contact tonometers (Pulsair, Xpert-NCT and CT-20) compare with the Goldmann tonometer (GT). Sensitivity, specificity, positive and negative predictive values were all evaluated for an intraocular pressure (IOP) > or = 21 mm Hg. We also calculated the mean IOP, the correlation and the dispersion of the results. The difficulty in using the instruments, the patient's attitude and subjective comfort of IOP measuring were also evaluated. We describe the advantages and shortcomings of non-contact tonometers as screening tools to detect elevated IOP in the general population.

  8. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    , and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba......Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions...

  9. Comparisons between designs for single-sided linear electric motors: Homopolar synchronous and induction

    Science.gov (United States)

    Nondahl, T. A.; Richter, E.

    1980-09-01

    A design study of two types of single sided (with a passive rail) linear electric machine designs, namely homopolar linear synchronous machines (LSM's) and linear induction machines (LIM's), is described. It is assumed the machines provide tractive effort for several types of light rail vehicles and locomotives. These vehicles are wheel supported and require tractive powers ranging from 200 kW to 3735 kW and top speeds ranging from 112 km/hr to 400 km/hr. All designs are made according to specified magnetic and thermal criteria. The LSM advantages are a higher power factor, much greater restoring forces for track misalignments, and less track heating. The LIM advantages are no need to synchronize the excitation frequency precisely to vehicle speed, simpler machine construction, and a more easily anchored track structure. The relative weights of the two machine types vary with excitation frequency and speed; low frequencies and low speeds favor the LSM.

  10. Full area covered 3D profile measurement of special-shaped optics based on a new prototype non-contact profiler.

    Science.gov (United States)

    Du, Hui-Lin; Zhou, Zhao-Zhong; Sun, Ze-Qing; Ju, Bing-Feng; Xu, Shaoning; Sun, Anyu

    2017-06-01

    A new prototype non-contact profiler based on surface tracking has been specially developed. Surface tracking is carried out by a specially designed dual stage probe system with the aid of a four-Degree Of Freedom high-precision motion platform. The dual stage probe system keeps a short-range optical probe constantly tracking the surface by a self-developed voice coil motor servo, by which a wide measuring range of up to 10 mm is realized. The system performance evaluation including resolution, repeatability, and scanning speed proved the good capability of the new prototype non-contact profiler. To realize a full area covered 3D profile measurement of special-shaped optics within one scanning procedure, a signal intensity monitor integrated in the surface tracking controller is specially developed. In the experiment, a snip-single-corner-rectangular-shaped freeform surface was successfully measured over full area by the new non-contact profiler. This work provides an effective solution for 3D profile measurement of special-shaped optical surfaces over full reflecting area. Experimental results demonstrate that the proposed measuring system is of great significance in quality evaluation of optical surfaces.

  11. Complex motor task associated with non-linear BOLD responses in cerebro-cortical areas and cerebellum.

    Science.gov (United States)

    Alahmadi, Adnan A S; Samson, Rebecca S; Gasston, David; Pardini, Matteo; Friston, Karl J; D'Angelo, Egidio; Toosy, Ahmed T; Wheeler-Kingshott, Claudia A M

    2016-06-01

    Previous studies have used fMRI to address the relationship between grip force (GF) applied to an object and BOLD response. However, whilst the majority of these studies showed a linear relationship between GF and neural activity in the contralateral M1 and ipsilateral cerebellum, animal studies have suggested the presence of non-linear components in the GF-neural activity relationship. Here, we present a methodology for assessing non-linearities in the BOLD response to different GF levels, within primary motor as well as sensory and cognitive areas and the cerebellum. To be sensitive to complex forms, we designed a feasible grip task with five GF targets using an event-related visually guided paradigm and studied a cohort of 13 healthy volunteers. Polynomial functions of increasing order were fitted to the data. (1) activated motor areas irrespective of GF; (2) positive higher-order responses in and outside M1, involving premotor, sensory and visual areas and cerebellum; (3) negative correlations with GF, predominantly involving the visual domain. Overall, our results suggest that there are physiologically consistent behaviour patterns in cerebral and cerebellar cortices; for example, we observed the presence of a second-order effect in sensorimotor areas, consistent with an optimum metabolic response at intermediate GF levels, while higher-order behaviour was found in associative and cognitive areas. At higher GF levels, sensory-related cortical areas showed reduced activation, interpretable as a redistribution of the neural activity for more demanding tasks. These results have the potential of opening new avenues for investigating pathological mechanisms of neurological diseases.

  12. Quantitative sub-surface and non-contact imaging using scanning microwave microscopy

    International Nuclear Information System (INIS)

    Gramse, Georg; Kasper, Manuel; Hinterdorfer, Peter; Brinciotti, Enrico; Rankl, Christian; Kienberger, Ferry; Lucibello, Andrea; Marcelli, Romolo; Patil, Samadhan B.; Giridharagopal, Rajiv

    2015-01-01

    The capability of scanning microwave microscopy for calibrated sub-surface and non-contact capacitance imaging of silicon (Si) samples is quantitatively studied at broadband frequencies ranging from 1 to 20 GHz. Calibrated capacitance images of flat Si test samples with varying dopant density (10 15 –10 19 atoms cm −3 ) and covered with dielectric thin films of SiO 2 (100–400 nm thickness) are measured to demonstrate the sensitivity of scanning microwave microscopy (SMM) for sub-surface imaging. Using standard SMM imaging conditions the dopant areas could still be sensed under a 400 nm thick oxide layer. Non-contact SMM imaging in lift-mode and constant height mode is quantitatively demonstrated on a 50 nm thick SiO 2 test pad. The differences between non-contact and contact mode capacitances are studied with respect to the main parameters influencing the imaging contrast, namely the probe tip diameter and the tip–sample distance. Finite element modelling was used to further analyse the influence of the tip radius and the tip–sample distance on the SMM sensitivity. The understanding of how the two key parameters determine the SMM sensitivity and quantitative capacitances represents an important step towards its routine application for non-contact and sub-surface imaging. (paper)

  13. [Comparative pressure measurements with the non-contact tonometer and the Goldmann applanation tonometer].

    Science.gov (United States)

    Langmann, G; Schuhmann, G; Schwaiger, W

    1985-11-01

    The intraocular pressure of 400 patients was measured with both the Non-Contact Tonometer II (NCT II) and the Goldmann applanation tonometer (GAT) and was statistically evaluated. The clinical experience gained, as well as advantages and limitations in application, are discussed.

  14. Persistent current analysis of superconducting coils in a linear synchronous motor for maglev passenger transport system. Fujoshiki tetsudoyo linear doki motor ni okeru teijisoku mode chodendo coil denryu no kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Azusawa, T [Toshiba Corp., Tokyo (Japan)

    1994-05-20

    The simple analysis method of persistent current induced in on-board superconducting coils was proposed for the vehicle of a superconducting magnetically-suspended train which is running in the magnetic field generated by armature coil current of a linear synchronous motor installed along a guideway, and the performance of the method is discussed through calculation based on typical models. As fluctuation of persistent current due to running was calculated with various parameter values under a normal running condition, fluctuation of persistent current induced was less then 1% of an initial magnetomotive force, having no adverse effect on the stability and reliability of superconducting magnets. Electromagnetic forces under a normal running condition could be predicted accurately enough by relatively easy-to-calculate constant current mode analysis. Double-layered armature coils were preferred to single-layered ones to enhance the stability of superconducting magnets by reducing fluctuation of persistent current. 10 refs., 8 figs., 1 tab.

  15. Body mass index and motor coordination: Non-linear relationships in children 6-10 years.

    Science.gov (United States)

    Lopes, V P; Malina, R M; Maia, J A R; Rodrigues, L P

    2018-05-01

    Given the concern for health-related consequences of an elevated body mass index (BMI; obesity), the potential consequences of a low BMI in children are often overlooked. The purpose was to evaluate the relationship between the BMI across its entire spectrum and motor coordination (MC) in children 6-10 years. Height, weight, and MC (Körperkoordinationstest für Kinder, KTK test battery) were measured in 1,912 boys and 1,826 girls of 6-10 years of age. BMI (kg/m 2 ) was calculated. KTK scores for each of the four tests were also converted to a motor quotient (MQ). One-way ANOVA was used to test differences in the BMI, individual test items, and MQ among boys and girls within age groups. Sex-specific quadratic regressions of individual KTK items and the MQ on the BMI were calculated. Girls and boys were also classified into four weight status groups using International Obesity Task Force criteria: thin, normal, overweight, and obese. Differences in specific test items and MQ between weight status groups were evaluated by age group in each sex. Thirty-one percent of the sample was overweight or obese, whereas 5% was thin. On average, normal weight children had the highest MQ in both sexes across the age range with few exceptions. Overweight/obese children had a lower MQ than normal weight and thin children. The quadratic regression lines generally presented an inverted parabolic relationship between the BMI and MC and suggested a decrease in MC with an increase in the BMI. In general, BMI shows a curvilinear, inverted parabolic relationship with MC in children 6-10 years. © 2018 John Wiley & Sons Ltd.

  16. Improved protein structure reconstruction using secondary structures, contacts at higher distance thresholds, and non-contacts.

    Science.gov (United States)

    Adhikari, Badri; Cheng, Jianlin

    2017-08-29

    Residue-residue contacts are key features for accurate de novo protein structure prediction. For the optimal utilization of these predicted contacts in folding proteins accurately, it is important to study the challenges of reconstructing protein structures using true contacts. Because contact-guided protein modeling approach is valuable for predicting the folds of proteins that do not have structural templates, it is necessary for reconstruction studies to focus on hard-to-predict protein structures. Using a data set consisting of 496 structural domains released in recent CASP experiments and a dataset of 150 representative protein structures, in this work, we discuss three techniques to improve the reconstruction accuracy using true contacts - adding secondary structures, increasing contact distance thresholds, and adding non-contacts. We find that reconstruction using secondary structures and contacts can deliver accuracy higher than using full contact maps. Similarly, we demonstrate that non-contacts can improve reconstruction accuracy not only when the used non-contacts are true but also when they are predicted. On the dataset consisting of 150 proteins, we find that by simply using low ranked predicted contacts as non-contacts and adding them as additional restraints, can increase the reconstruction accuracy by 5% when the reconstructed models are evaluated using TM-score. Our findings suggest that secondary structures are invaluable companions of contacts for accurate reconstruction. Confirming some earlier findings, we also find that larger distance thresholds are useful for folding many protein structures which cannot be folded using the standard definition of contacts. Our findings also suggest that for more accurate reconstruction using predicted contacts it is useful to predict contacts at higher distance thresholds (beyond 8 Å) and predict non-contacts.

  17. Assessment of the accuracy and reliability of the Topcon CT80 non-contact tonometer.

    Science.gov (United States)

    Ogbuehi, Kelechi C

    2006-09-01

    The reliability of non-contact tonometers has been reported extensively in the literature. This study was designed to assess reliability of the new Topcon CT80 non-contact tonometer in normotensive subjects, using the Goldmann tonometer as the standard. The accuracy of the Topcon CT 80 non-contact tonometer was assessed by comparing its IOP assessments with those of the Goldmann applanation tonometer, on 60 right eyes of young healthy subjects with normal intraocular pressures. Each subject's intraocular pressure was assessed with each technique on two separate occasions, one week apart. The reliability of each technique was determined by the assessment of its inter-session repeatability using the Bland-Altman method. The 95 per cent limits of agreement for the two methods were also determined. No statistically significant difference was found between the average intraocular pressures measured with the two techniques (p > 0.05). The inter-session repeatability indices for the two techniques did not differ significantly (p > 0.05). The mean difference in intraocular measurements between the two techniques was 0.2 +/- 1.5 mmHg (mean +/- SD) and the 95 per cent limits of agreement were -3.14 and +2.74 mmHg, with the non-contact tonometer returning higher readings than the Goldmann tonometer. In this sample of normotensive subjects, the Topcon CT80 non-contact tonometer proved to be accurate and as reliable as the Goldmann tonometer in the assessment of intraocular pressure. Thus, it can be used as an objective clinical method for the assessment of normal intraocular pressure.

  18. Ocular surface displacement with and without contact lenses during non-contact tonometry.

    Directory of Open Access Journals (Sweden)

    Ulfah Rimayanti

    Full Text Available PURPOSE: To evaluate the displacement of the central ocular surface during non-contact tonometry with and without soft contact lenses and determine the factors associated with the displacement of the central ocular surface and intraocular pressure (IOP reading changes caused by wearing soft contact lenses (CLs. METHODS: One eye each in 21 subjects was studied. The cornea was photographed using a high-speed camera at 5,000 frames/sec during non-contact tonometry without contact lenses (NCL, with -5.0 diopters (D, -0.5 D and +5.0 D CL. The displacement of the ocular surface and the factors affecting displacement at the IOP reading and maximum displacement time were investigated. RESULTS: The IOP readings while wearing +5 D CL were significantly higher than those obtained while wearing -5 D CL. The ocular surface displacement between +5 D CL and other groups were significantly different. A significant positive correlation was found between the ocular surface displacement of subjects at the IOP reading time and the IOP obtained with the non-contact tonometer. A significant negative correlation was found between the ocular surface curvature and the IOP obtained using the non-contact tonometer. The radius of curvature of the ocular surface affected the displacement during the IOP reading and maximum displacement time. CONCLUSIONS: Our results indicate that soft contact lens use changes the ocular surface behavior and IOP readings during non-contact tonometry. The radius of curvature of the eye affects the ocular surface displacement and IOP readings in this situation.

  19. Ocular surface displacement with and without contact lenses during non-contact tonometry.

    Science.gov (United States)

    Rimayanti, Ulfah; Kiuchi, Yoshiaki; Uemura, Shohei; Takenaka, Joji; Mochizuki, Hideki; Kaneko, Makoto

    2014-01-01

    To evaluate the displacement of the central ocular surface during non-contact tonometry with and without soft contact lenses and determine the factors associated with the displacement of the central ocular surface and intraocular pressure (IOP) reading changes caused by wearing soft contact lenses (CLs). One eye each in 21 subjects was studied. The cornea was photographed using a high-speed camera at 5,000 frames/sec during non-contact tonometry without contact lenses (NCL), with -5.0 diopters (D), -0.5 D and +5.0 D CL. The displacement of the ocular surface and the factors affecting displacement at the IOP reading and maximum displacement time were investigated. The IOP readings while wearing +5 D CL were significantly higher than those obtained while wearing -5 D CL. The ocular surface displacement between +5 D CL and other groups were significantly different. A significant positive correlation was found between the ocular surface displacement of subjects at the IOP reading time and the IOP obtained with the non-contact tonometer. A significant negative correlation was found between the ocular surface curvature and the IOP obtained using the non-contact tonometer. The radius of curvature of the ocular surface affected the displacement during the IOP reading and maximum displacement time. Our results indicate that soft contact lens use changes the ocular surface behavior and IOP readings during non-contact tonometry. The radius of curvature of the eye affects the ocular surface displacement and IOP readings in this situation.

  20. The operation of a single-sided linear induction motor with squirrel-cage and solid-steel reaction rails

    Science.gov (United States)

    Eastham, A. R.; Katz, R. M.

    1980-09-01

    Two test programs have been conducted to evaluate the performance of a single-sided linear induction motor with a squirrel-cage reaction rail and with a solid steel reaction rail. A 1.73-m-long six-pole stator interacted with the rails mounted on the rim of a 7.6-m-diam wheel. A 64-channel data acquisition system allowed tests to be performed over a wide range of operating conditions at speeds up to 20 m/sec. Typical test results which compare and contrast the mechanical, electrical and magnetic behavior of the SLIMs are presented. The test data are being used to assess the SLIM as an integrated suspension/propulsion system and for other transportation applications.

  1. Three dimensional force prediction in a model linear brushless dc motor

    Energy Technology Data Exchange (ETDEWEB)

    Moghani, J.S.; Eastham, J.F.; Akmese, R.; Hill-Cottingham, R.J. (Univ. of Bath (United Kingdom). School of Electronic and Electric Engineering)

    1994-11-01

    Practical results are presented for the three axes forces produced on the primary of a linear brushless dc machine which is supplied from a three-phase delta-modulated inverter. Conditions of both lateral alignment and lateral displacement are considered. Finite element analysis using both two and three dimensional modeling is compared with the practical results. It is shown that a modified two dimensional model is adequate, where it can be used, in the aligned position and that the full three dimensional method gives good results when the machine is axially misaligned.

  2. Linear and nonlinear auditory response properties of interneurons in a high-order avian vocal motor nucleus during wakefulness.

    Science.gov (United States)

    Raksin, Jonathan N; Glaze, Christopher M; Smith, Sarah; Schmidt, Marc F

    2012-04-01

    Motor-related forebrain areas in higher vertebrates also show responses to passively presented sensory stimuli. However, sensory tuning properties in these areas, especially during wakefulness, and their relation to perception, are poorly understood. In the avian song system, HVC (proper name) is a vocal-motor structure with auditory responses well defined under anesthesia but poorly characterized during wakefulness. We used a large set of stimuli including the bird's own song (BOS) and many conspecific songs (CON) to characterize auditory tuning properties in putative interneurons (HVC(IN)) during wakefulness. Our findings suggest that HVC contains a diversity of responses that vary in overall excitability to auditory stimuli, as well as bias in spike rate increases to BOS over CON. We used statistical tests to classify cells in order to further probe auditory responses, yielding one-third of neurons that were either unresponsive or suppressed and two-thirds with excitatory responses to one or more stimuli. A subset of excitatory neurons were tuned exclusively to BOS and showed very low linearity as measured by spectrotemporal receptive field analysis (STRF). The remaining excitatory neurons responded well to CON stimuli, although many cells still expressed a bias toward BOS. These findings suggest the concurrent presence of a nonlinear and a linear component to responses in HVC, even within the same neuron. These characteristics are consistent with perceptual deficits in distinguishing BOS from CON stimuli following lesions of HVC and other song nuclei and suggest mirror neuronlike qualities in which "self" (here BOS) is used as a referent to judge "other" (here CON).

  3. Using a generalized linear mixed model approach to explore the role of age, motor proficiency, and cognitive styles in children's reach estimation accuracy.

    Science.gov (United States)

    Caçola, Priscila M; Pant, Mohan D

    2014-10-01

    The purpose was to use a multi-level statistical technique to analyze how children's age, motor proficiency, and cognitive styles interact to affect accuracy on reach estimation tasks via Motor Imagery and Visual Imagery. Results from the Generalized Linear Mixed Model analysis (GLMM) indicated that only the 7-year-old age group had significant random intercepts for both tasks. Motor proficiency predicted accuracy in reach tasks, and cognitive styles (object scale) predicted accuracy in the motor imagery task. GLMM analysis is suitable to explore age and other parameters of development. In this case, it allowed an assessment of motor proficiency interacting with age to shape how children represent, plan, and act on the environment.

  4. Bayesian integration and non-linear feedback control in a full-body motor task.

    Science.gov (United States)

    Stevenson, Ian H; Fernandes, Hugo L; Vilares, Iris; Wei, Kunlin; Körding, Konrad P

    2009-12-01

    A large number of experiments have asked to what degree human reaching movements can be understood as being close to optimal in a statistical sense. However, little is known about whether these principles are relevant for other classes of movements. Here we analyzed movement in a task that is similar to surfing or snowboarding. Human subjects stand on a force plate that measures their center of pressure. This center of pressure affects the acceleration of a cursor that is displayed in a noisy fashion (as a cloud of dots) on a projection screen while the subject is incentivized to keep the cursor close to a fixed position. We find that salient aspects of observed behavior are well-described by optimal control models where a Bayesian estimation model (Kalman filter) is combined with an optimal controller (either a Linear-Quadratic-Regulator or Bang-bang controller). We find evidence that subjects integrate information over time taking into account uncertainty. However, behavior in this continuous steering task appears to be a highly non-linear function of the visual feedback. While the nervous system appears to implement Bayes-like mechanisms for a full-body, dynamic task, it may additionally take into account the specific costs and constraints of the task.

  5. Bayesian integration and non-linear feedback control in a full-body motor task.

    Directory of Open Access Journals (Sweden)

    Ian H Stevenson

    2009-12-01

    Full Text Available A large number of experiments have asked to what degree human reaching movements can be understood as being close to optimal in a statistical sense. However, little is known about whether these principles are relevant for other classes of movements. Here we analyzed movement in a task that is similar to surfing or snowboarding. Human subjects stand on a force plate that measures their center of pressure. This center of pressure affects the acceleration of a cursor that is displayed in a noisy fashion (as a cloud of dots on a projection screen while the subject is incentivized to keep the cursor close to a fixed position. We find that salient aspects of observed behavior are well-described by optimal control models where a Bayesian estimation model (Kalman filter is combined with an optimal controller (either a Linear-Quadratic-Regulator or Bang-bang controller. We find evidence that subjects integrate information over time taking into account uncertainty. However, behavior in this continuous steering task appears to be a highly non-linear function of the visual feedback. While the nervous system appears to implement Bayes-like mechanisms for a full-body, dynamic task, it may additionally take into account the specific costs and constraints of the task.

  6. Linear associations between clinically assessed upper motor neuron disease and diffusion tensor imaging metrics in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Woo, John H; Wang, Sumei; Melhem, Elias R; Gee, James C; Cucchiara, Andrew; McCluskey, Leo; Elman, Lauren

    2014-01-01

    To assess the relationship between clinically assessed Upper Motor Neuron (UMN) disease in Amyotrophic Lateral Sclerosis (ALS) and local diffusion alterations measured in the brain corticospinal tract (CST) by a tractography-driven template-space region-of-interest (ROI) analysis of Diffusion Tensor Imaging (DTI). This cross-sectional study included 34 patients with ALS, on whom DTI was performed. Clinical measures were separately obtained including the Penn UMN Score, a summary metric based upon standard clinical methods. After normalizing all DTI data to a population-specific template, tractography was performed to determine a region-of-interest (ROI) outlining the CST, in which average Mean Diffusivity (MD) and Fractional Anisotropy (FA) were estimated. Linear regression analyses were used to investigate associations of DTI metrics (MD, FA) with clinical measures (Penn UMN Score, ALSFRS-R, duration-of-disease), along with age, sex, handedness, and El Escorial category as covariates. For MD, the regression model was significant (p = 0.02), and the only significant predictors were the Penn UMN Score (p = 0.005) and age (p = 0.03). The FA regression model was also significant (p = 0.02); the only significant predictor was the Penn UMN Score (p = 0.003). Measured by the template-space ROI method, both MD and FA were linearly associated with the Penn UMN Score, supporting the hypothesis that DTI alterations reflect UMN pathology as assessed by the clinical examination.

  7. Non-contact translation-rotation sensor using combined effects of magnetostriction and piezoelectricity.

    Science.gov (United States)

    Yang, Bintang; Liu, Qingwei; Zhang, Ting; Cao, Yudong; Feng, Zhiqiang; Meng, Guang

    2012-10-15

    Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  8. Non-Contact Translation-Rotation Sensor Using Combined Effects of Magnetostriction and Piezoelectricity

    Directory of Open Access Journals (Sweden)

    Guang Meng

    2012-10-01

    Full Text Available Precise displacement sensors are an important topic in precision engineering. At present, this type of sensors typically have a single feature of either translation or rotation measurement. They are also inconvenient to integrate with the host devices. In this report we propose a new kind of sensor that enables both translation and rotation measurement by using the combined effect of magnetostriction and piezoelectricity. As a proof of concept, we experimentally realized a prototype of non-contact translation-rotation precise sensor. In the current research stage, through both theoretical and experimental study, the non-contact displacement sensor is shown to be feasible for measuring both translation and rotation either in coarse or fine measurement. Moreover, owing to its compact, rigid structure and fewer components, it can be easily embedded in host equipment.

  9. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions......, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  10. Secondary seal effects in hydrostatic non-contact seals for reactor coolant pump shaft

    International Nuclear Information System (INIS)

    Fujita, T.; Koga, T.; Tanoue, H.; Hirabayashi, H.

    1987-01-01

    The paper presents a seal flow analysis in a hydrostatic non-contact seal for a PWR coolant pump shaft. A description is given of the non-contact seal for the reactor coolant pump. Results are presented for a distortion analysis of the seal ring, along with the seal flow characteristics and the contact pressure profiles of the secondary seals. The results of the work confirm previously reported findings that the seal ring distortion is sensitive to the o-ring location (which was placed between the ceramic seal face and the seal ring retainer). The paper concludes that the seal flow characteristics and the tracking performance depend upon the dynamic properties of the secondary seal. (U.K.)

  11. Contact and non-contact ultrasonic measurement in the food industry: a review

    International Nuclear Information System (INIS)

    Mohd Khairi, Mohd Taufiq; Ibrahim, Sallehuddin; Md Yunus, Mohd Amri; Faramarzi, Mahdi

    2016-01-01

    The monitoring of the food manufacturing process is vital since it determines the safety and quality level of foods which directly affect the consumers’ health. Companies which produce high quality products will gain trust from consumers. This factor helps the companies to make profits. The use of efficient and appropriate sensors for the monitoring process can also reduce cost. The food assessing process based on an ultrasonic sensor has attracted the attention of the food industry due to its excellent capabilities in several applications. The utilization of low or high frequencies for the ultrasonic transducer has provided an enormous benefit for analysing, modifying and guaranteeing the quality of food. The contact and non-contact ultrasonic modes for measurement also contributed significantly to the food processing. This paper presents a review of the application of the contact and non-contact mode of ultrasonic measurement focusing on safety and quality control areas. The results from previous researches are shown and elaborated. (topical review)

  12. Contact and non-contact ultrasonic measurement in the food industry: a review

    Science.gov (United States)

    Taufiq Mohd Khairi, Mohd; Ibrahim, Sallehuddin; Yunus, Mohd Amri Md; Faramarzi, Mahdi

    2016-01-01

    The monitoring of the food manufacturing process is vital since it determines the safety and quality level of foods which directly affect the consumers’ health. Companies which produce high quality products will gain trust from consumers. This factor helps the companies to make profits. The use of efficient and appropriate sensors for the monitoring process can also reduce cost. The food assessing process based on an ultrasonic sensor has attracted the attention of the food industry due to its excellent capabilities in several applications. The utilization of low or high frequencies for the ultrasonic transducer has provided an enormous benefit for analysing, modifying and guaranteeing the quality of food. The contact and non-contact ultrasonic modes for measurement also contributed significantly to the food processing. This paper presents a review of the application of the contact and non-contact mode of ultrasonic measurement focusing on safety and quality control areas. The results from previous researches are shown and elaborated.

  13. Measurement properties and usability of non-contact scanners for measuring transtibial residual limb volume.

    Science.gov (United States)

    Kofman, Rianne; Beekman, Anna M; Emmelot, Cornelis H; Geertzen, Jan H B; Dijkstra, Pieter U

    2018-06-01

    Non-contact scanners may have potential for measurement of residual limb volume. Different non-contact scanners have been introduced during the last decades. Reliability and usability (practicality and user friendliness) should be assessed before introducing these systems in clinical practice. The aim of this study was to analyze the measurement properties and usability of four non-contact scanners (TT Design, Omega Scanner, BioSculptor Bioscanner, and Rodin4D Scanner). Quasi experimental. Nine (geometric and residual limb) models were measured on two occasions, each consisting of two sessions, thus in total 4 sessions. In each session, four observers used the four systems for volume measurement. Mean for each model, repeatability coefficients for each system, variance components, and their two-way interactions of measurement conditions were calculated. User satisfaction was evaluated with the Post-Study System Usability Questionnaire. Systematic differences between the systems were found in volume measurements. Most of the variances were explained by the model (97%), while error variance was 3%. Measurement system and the interaction between system and model explained 44% of the error variance. Repeatability coefficient of the systems ranged from 0.101 (Omega Scanner) to 0.131 L (Rodin4D). Differences in Post-Study System Usability Questionnaire scores between the systems were small and not significant. The systems were reliable in determining residual limb volume. Measurement systems and the interaction between system and residual limb model explained most of the error variances. The differences in repeatability coefficient and usability between the four CAD/CAM systems were small. Clinical relevance If accurate measurements of residual limb volume are required (in case of research), modern non-contact scanners should be taken in consideration nowadays.

  14. Modeling leukocyte-leukocyte non-contact interactions in a lymph node.

    Science.gov (United States)

    Gritti, Nicola; Caccia, Michele; Sironi, Laura; Collini, Maddalena; D'Alfonso, Laura; Granucci, Francesca; Zanoni, Ivan; Chirico, Giuseppe

    2013-01-01

    The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines) allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (~25% increase) upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

  15. Structural, Functional, and Metabolic Brain Markers Differentiate Collision versus Contact and Non-Contact Athletes.

    Science.gov (United States)

    Churchill, Nathan W; Hutchison, Michael G; Di Battista, Alex P; Graham, Simon J; Schweizer, Tom A

    2017-01-01

    There is growing concern about how participation in contact sports affects the brain. Retrospective evidence suggests that contact sports are associated with long-term negative health outcomes. However, much of the research to date has focused on former athletes with significant health problems. Less is known about the health of current athletes in contact and collision sports who have not reported significant medical issues. In this cross-sectional study, advanced magnetic resonance imaging (MRI) was used to evaluate multiple aspects of brain physiology in three groups of athletes participating in non-contact sports ( N  = 20), contact sports ( N  = 22), and collision sports ( N  = 23). Diffusion tensor imaging was used to assess white matter microstructure based on measures of fractional anisotropy (FA) and mean diffusivity (MD); resting-state functional MRI was used to evaluate global functional connectivity; single-voxel spectroscopy was used to compare ratios of neural metabolites, including N -acetyl aspartate (NAA), creatine (Cr), choline, and myo-inositol. Multivariate analysis revealed structural, functional, and metabolic measures that reliably differentiated between sport groups. The collision group had significantly elevated FA and reduced MD in white matter, compared to both contact and non-contact groups. In contrast, the collision group showed significant reductions in functional connectivity and the NAA/Cr metabolite ratio, relative to only the non-contact group, while the contact group overlapped with both non-contact and collision groups. For brain regions associated with contact sport participation, athletes with a history of concussion also showed greater alterations in FA and functional connectivity, indicating a potential cumulative effect of both contact exposure and concussion history on brain physiology. These findings indicate persistent differences in brain physiology for athletes participating in contact and collision sports

  16. Analytical model development of an eddy-current-based non-contacting steel plate conveyance system

    International Nuclear Information System (INIS)

    Liu, C.-T.; Lin, S.-Y.; Yang, Y.-Y.; Hwang, C.-C.

    2008-01-01

    A concise model for analyzing and predicting the quasi-static electromagnetic characteristics of an eddy-current-based non-contacting steel plate conveyance system has been developed. Confirmed by three-dimensional (3-D) finite element analysis (FEA), adequacy of the analytical model can be demonstrated. Such an effective approach, which can be conveniently used by the potential industries for preliminary system operational performance evaluations, will be essential for designers and on-site engineers

  17. Modeling leukocyte-leukocyte non-contact interactions in a lymph node.

    Directory of Open Access Journals (Sweden)

    Nicola Gritti

    Full Text Available The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (~25% increase upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

  18. Measuring Pulse Rate Variability using Long-Range, Non-Contact Imaging Photoplethysmography

    Science.gov (United States)

    2016-08-20

    contains color . 14. ABSTRACT Camera-based measurement of the blood volume pulse via non-contact, imaging photoplethysmography is a very popular approach...ECG) for each window were calculated in beats per minute (bpm). The periodogram method with a Hamming window was used to estimate mean pulse...11 Hz. Independent component analysis (ICA) was then used to decompose the normalized, bandpass-filtered, color -channel signals into independent

  19. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury

    OpenAIRE

    Viswanath, Y; Rogers, I

    1999-01-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein byp...

  20. Non-Contact Plant Growth Measurement Method and System Based on Ubiquitous Sensor Network Technologies

    Directory of Open Access Journals (Sweden)

    Intae Ryoo

    2011-04-01

    Full Text Available This paper proposes a non-contact plant growth measurement system using infrared sensors based on the ubiquitous sensor network (USN technology. The proposed system measures plant growth parameters such as the stem radius of plants using real-time non-contact methods, and generates diameter, cross-sectional area and thickening form of plant stems using this measured data. Non-contact sensors have been used not to cause any damage to plants during measurement of the growth parameters. Once the growth parameters are measured, they are transmitted to a remote server using the sensor network technology and analyzed in the application program server. The analyzed data are then provided for administrators and a group of interested users. The proposed plant growth measurement system has been designed and implemented using fixed-type and rotary-type infrared sensor based measurement methods and devices. Finally, the system performance is compared and verified with the measurement data that have been obtained by practical field experiments.

  1. An investigation of highly accurate and precise robotic hole measurements using non-contact devices

    Directory of Open Access Journals (Sweden)

    Usman Zahid

    2016-01-01

    Full Text Available Industrial robots arms are widely used in manufacturing industry because of their support for automation. However, in metrology, robots have had limited application due to their insufficient accuracy. Even using error compensation and calibration methods, robots are not effective for micrometre (μm level metrology. Non-contact measurement devices can potentially enable the use of robots for highly accurate metrology. However, the use of such devices on robots has not been investigated. The research work reported in this paper explores the use of different non-contact measurement devices on an industrial robot. The aim is to experimentally investigate the effects of robot movements on the accuracy and precision of measurements. The focus has been on assessing the ability to accurately measure various geometric and surface parameters of holes despite the inherent inaccuracies of industrial robot. This involves the measurement of diameter, roundness and surface roughness. The study also includes scanning of holes for measuring internal features such as start and end point of a taper. Two different non-contact measurement devices based on different technologies are investigated. Furthermore, effects of eccentricity, vibrations and thermal variations are also assessed. The research contributes towards the use of robots for highly accurate and precise robotic metrology.

  2. Non-contact radio frequency shielding and wave guiding by multi-folded transformation optics method.

    Science.gov (United States)

    Madni, Hamza Ahmad; Zheng, Bin; Yang, Yihao; Wang, Huaping; Zhang, Xianmin; Yin, Wenyan; Li, Erping; Chen, Hongsheng

    2016-11-14

    Compared with conventional radio frequency (RF) shielding methods in which the conductive coating material encloses the circuits design and the leakage problem occurs due to the gap in such conductive material, non-contact RF shielding at a distance is very promising but still impossible to achieve so far. In this paper, a multi-folded transformation optics method is proposed to design a non-contact device for RF shielding. This "open-shielded" device can shield any object at a distance from the electromagnetic waves at the operating frequency, while the object is still physically open to the outer space. Based on this, an open-carpet cloak is proposed and the functionality of the open-carpet cloak is demonstrated. Furthermore, we investigate a scheme of non-contact wave guiding to remotely control the propagation of surface waves over any obstacles. The flexibilities of such multi-folded transformation optics method demonstrate the powerfulness of the method in the design of novel remote devices with impressive new functionalities.

  3. Non-contact evaluation of milk-based products using air-coupled ultrasound

    Science.gov (United States)

    Meyer, S.; Hindle, S. A.; Sandoz, J.-P.; Gan, T. H.; Hutchins, D. A.

    2006-07-01

    An air-coupled ultrasonic technique has been developed and used to detect physicochemical changes of liquid beverages within a glass container. This made use of two wide-bandwidth capacitive transducers, combined with pulse-compression techniques. The use of a glass container to house samples enabled visual inspection, helping to verify the results of some of the ultrasonic measurements. The non-contact pulse-compression system was used to evaluate agglomeration processes in milk-based products. It is shown that the amplitude of the signal varied with time after the samples had been treated with lactic acid, thus promoting sample destabilization. Non-contact imaging was also performed to follow destabilization of samples by scanning in various directions across the container. The obtained ultrasonic images were also compared to those from a digital camera. Coagulation with glucono-delta-lactone of skim milk poured into this container could be monitored within a precision of a pH of 0.15. This rapid, non-contact and non-destructive technique has shown itself to be a feasible method for investigating the quality of milk-based beverages, and possibly other food products.

  4. Airborne non-contact and contact broadband ultrasounds for frequency attenuation profile estimation of cementitious materials.

    Science.gov (United States)

    Gosálbez, J; Wright, W M D; Jiang, W; Carrión, A; Genovés, V; Bosch, I

    2018-08-01

    In this paper, the study of frequency-dependent ultrasonic attenuation in strongly heterogeneous cementitious materials is addressed. To accurately determine the attenuation over a wide frequency range, it is necessary to have suitable excitation techniques. We have analysed two kinds of ultrasound techniques: contact ultrasound and airborne non-contact ultrasound. The mathematical formulation for frequency-dependent attenuation has been established and it has been revealed that each technique may achieve similar results but requires specific different calibration processes. In particular, the airborne non-contact technique suffers high attenuation due to energy losses at the air-material interfaces. Thus, its bandwidth is limited to low frequencies but it does not require physical contact between transducer and specimen. In contrast, the classical contact technique can manage higher frequencies but the measurement depends on the pressure between the transducer and the specimen. Cement specimens have been tested with both techniques and frequency attenuation dependence has been estimated. Similar results were achieved at overlapping bandwidth and it has been demonstrated that the airborne non-contact ultrasound technique could be a viable alternative to the classical contact technique. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. AIRGAP MAGNETIC INDUCTION DISTRIBUTION IN A COAXIALLY-LINEAR SYNCHRONOUS MOTOR WITH AXIAL AND RADIAL DIRECTION OF THE RUNNER PERMANENT MAGNETS MAGNETIZATION

    Directory of Open Access Journals (Sweden)

    Abbasian Mohsen

    2013-02-01

    Full Text Available Results of theoretical and experimental research on magnetic induction distribution in the air gap of a coaxially-linear synchronous motor with reciprocal motion within the pole pitch and axial and radial direction of the permanent magnets magnetization are presented.

  6. The monomeric, tetrameric, and fibrillar organization of Fib: the dynamic building block of the bacterial linear motor of Spiroplasma melliferum BC3.

    Science.gov (United States)

    Cohen-Krausz, Sara; Cabahug, Pamela C; Trachtenberg, Shlomo

    2011-07-08

    Spiroplasmas belong to the class Mollicutes, representing the minimal, free-living, and self-replicating forms of life. Spiroplasmas are helical wall-less bacteria and the only ones known to swim by means of a linear motor (rather than the near-universal rotary bacterial motor). The linear motor follows the shortest path along the cell's helical membranal tube. The motor is composed of a flat monolayered ribbon of seven parallel fibrils and is believed to function in controlling cell helicity and motility through dynamic, coordinated, differential length changes in the fibrils. The latter cause local perturbations of helical symmetry, which are essential for net directional displacement in environments with a low Reynolds number. The underlying fibrils' core building block is a circular tetramer of the 59-kDa protein Fib. The fibrils' differential length changes are believed to be driven by molecular switching of Fib, leading consequently to axial ratio and length changes in tetrameric rings. Using cryo electron microscopy, diffractometry, single-particle analysis of isolated ribbons, and sequence analyses of Fib, we determined the overall molecular organization of the Fib monomer, tetramer, fibril, and linear motor of Spiroplasma melliferum BC3 that underlies cell geometry and motility. Fib appears to be a bidomained molecule, of which the N-terminal half is apparently a globular phosphorylase. By a combination of reversible rotation and diagonal shift of Fib monomers, the tetramer adopts either a cross-like nonhanded conformation or a ring-like handed conformation. The sense of Fib rotation may determine the handedness of the linear motor and, eventually, of the cell. A further change in the axial ratio of the ring-like tetramers controls fibril lengths and the consequent helical geometry. Analysis of tetramer quadrants from adjacent fibrils clearly demonstrates local differential fibril lengths. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Mass distribution and spatial organization of the linear bacterial motor of Spiroplasma citri R8A2.

    Science.gov (United States)

    Trachtenberg, Shlomo; Andrews, S Brian; Leapman, Richard D

    2003-03-01

    In the simple, helical, wall-less bacterial genus Spiroplasma, chemotaxis and motility are effected by a linear, contractile motor arranged as a flat cytoskeletal ribbon attached to the inner side of the membrane along the shortest helical line. With scanning transmission electron microscopy and diffraction analysis, we determined the hierarchical and spatial organization of the cytoskeleton of Spiroplasma citri R8A2. The structural unit appears to be a fibril, approximately 5 nm wide, composed of dimers of a 59-kDa protein; each ribbon is assembled from seven fibril pairs. The functional unit of the intact ribbon is a pair of aligned fibrils, along which pairs of dimers form tetrameric ring-like repeats. On average, isolated and purified ribbons contain 14 fibrils or seven well-aligned fibril pairs, which are the same structures observed in the intact cell. Scanning transmission electron microscopy mass analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified cytoskeletons indicate that the 59-kDa protein is the only constituent of the ribbons.

  8. Improvement of superconducting cylindrical linear induction motor; Chodendo entogata tan'ichiji rinia yudo mota no tokusei kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kikuma, T.; Ishiyama, A. [Waseda Univ., Tokyo (Japan)

    2000-05-29

    For the purpose of examining the characteristics (effect of stability and ac loss by the higher harmonic wave etc.) of an alternating current superconductivity winding under a real machine operating environment of the super-conductive AC machine vessel, authors produced a cylindrical shortness first linear guiding motor (SCLIM) which used the NbTi/CuNi super-conducting cable for the first excitation winding experimentally. In this study, the evaluation of the start up thrust and operation confirmation of the quenching detection protection circuit were carried out using the produced SCLIM. In the quenching detection protection control circuit, the first excitation winding was divided into an internal layer and an outer layer, and both layers were excited in the 2 layer division and a quenching detection protection circuit was installed on the 2 layers respectively. The circuit of a part of fact by this of the phase in which the quench was generated and observed was cut off, and the operation would be able to be continued in part of the remainder of the phase and other two phases. Here, it is to cut off the quenched phase from the circuit, when the phase current becomes zero, and the other effect on the phase is held as small as possible. (NEDO)

  9. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    Directory of Open Access Journals (Sweden)

    Abbas Abbas K

    2011-10-01

    Full Text Available Abstract Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI detection and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU. The promising results suggest to include this technology into advanced NICU monitors.

  10. A study on non-contact ultrasonic technique for on-line inspection of CFRP

    International Nuclear Information System (INIS)

    Lee, Seung-Joon; Park, Won-Su; Lee, Joon-Hyun; Byun, Joon-Hyung

    2007-01-01

    The advantages of carbon fiber reinforced plastic materials (CFRP) are: they are light structure materials, they have corrosion resistance, and higher specific strength and elasticity. The recently developed 3-dimentional fiber placement system is able to produce a more complex and various shaped structures due to less limitations of a product shape according to the problem in conventional fabrication process. This fiber placement system stacks the narrow prepreg tape on the mold according to the designed sequence and thickness. Non-destructive evaluation was rquired for these composites to evaluate changes in strength caused by defects such as delamination and porosity. Additionally, the expectent quality should be satisfied for the high cost fabrication process using the fiber placement system. Therefore, an on line non-destructive evaluation system is required and real-time complement is needed when the defects are detected [1]. Defect imaging by the ultrasonic C-scan method is a useful technique for defect detection in CFRP. However, the conventional ultrasonic C-scan technique cannot be applied during the fabrication process because the test piece should be immersed into the water. Therefore, non-contact ultrasonic techniques should be applied during the fabricating process. For the development of non-contact ultrasonic techniques available in non-destructive evaluation of CFRP, a recent laser-generated ultrasonic technique and an air-coupled transducer that transmit and receive ultrasounds in the air are studied [2-3]. In this study, generating and receiving techniques of laser-generated ultrasound and the characteristics of received signals upon the internal defects of CFRO were studied for non-contact inspection

  11. A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury.

    Science.gov (United States)

    Viswanath, Y K; Rogers, I M

    1999-09-01

    Complete knee dislocation is a rare injury and an associated incidence of popliteal artery damage ranges from 16-60% of cases. It occurs commonly in road traffic accidents and in high velocity trauma where significant contact remains as the usual mode of injury. We describe a rare case of non-contact knee dislocation with popliteal artery injury sustained while practising Aikido, a type of martial art. This patient successfully underwent closed reduction of the knee with an emergency vein bypass graft. Similar injury in association with Aikido has not been described in the English literature previously. Various martial art injuries are briefly discussed and safety recommendations made.

  12. Procedure of non-contacting local mass density and mass density distribution measurements

    International Nuclear Information System (INIS)

    Menzel, M.; Winkler, K.

    1985-01-01

    The invention has been aimed at a procedure of non-contacting local mass density and/or mass density distribution measurements i.e. without the interfering influence of sensors or probes. It can be applied to installations, apparatuses and pipings of chemical engineering, to tank constructions and transportation on extreme temperature and/or pressure conditions and aggressive media influences respectively. The procedure has utilized an ionizing quantum radiation whereby its unknown weakening and scattering is compensated by a suitable combination of scattering and transmission counter rate measurements in such a way that the local mass densities and the mass density distribution respectively are determinable

  13. Phenomenally High Transduction Air/gas Transducers for Practical Non-Contact Ultrasonic Applications

    Science.gov (United States)

    Bhardwaj, Mahesh C.

    2009-03-01

    Based on novel acoustic impedance matching layers and high coupling piezoelectric materials this paper describes exceptionally high air/gas transduction ultrasonic transducers. By providing applications oriented performance of these transducers we also usher in the era of much desired Non-Contact Ultrasound (NCU) testing and analysis of a wide range of materials including early stage formation of materials such as uncured composite prepregs, green ceramics and powder metals, plastics, elastomers, porous, hygroscopic, chemically bonded and other materials. Besides quality control, ultimately NCU offers timely opportunities for cost-effective materials production, energy savings, and environment protection.

  14. Long wavelength infrared radiation thermometry for non-contact temperature measurements in gas turbines

    Science.gov (United States)

    Manara, J.; Zipf, M.; Stark, T.; Arduini, M.; Ebert, H.-P.; Tutschke, A.; Hallam, A.; Hanspal, J.; Langley, M.; Hodge, D.; Hartmann, J.

    2017-01-01

    The objective of the EU project "Sensors Towards Advanced Monitoring and Control of Gas Turbine Engines (acronym STARGATE)" is the development of a suite of advanced sensors, instrumentation and related systems in order to contribute to the developing of the next generation of green and efficient gas turbine engines. One work package of the project deals with the design and development of a long wavelength infrared (LWIR) radiation thermometer for the non-contact measurement of the surface temperature of thermal barrier coatings (TBCs) during the operation of gas turbine engines. For opaque surfaces (e.g. metals or superalloys) radiation thermometers which are sensitive in the near or short wavelength infrared are used as state-of-the-art method for non-contact temperature measurements. But this is not suitable for oxide ceramic based TBCs (e.g. partially yttria stabilized zirconia) as oxide ceramics are semi-transparent in the near and short wavelength infrared spectral region. Fortunately the applied ceramic materials are non-transparent in the long wavelength infrared and additionally exhibit a high emittance in this wavelength region. Therefore, a LWIR pyrometer can be used for non-contact temperature measurements of the surfaces of TBCs as such pyrometers overcome the described limitation of existing techniques. For performing non-contact temperature measurements in gas turbines one has to know the infrared-optical properties of the applied TBCs as well as of the hot combustion gas in order to properly analyse the measurement data. For reaching a low uncertainty on the one hand the emittance of the TBC should be high (>0.9) in order to reduce reflections from the hot surrounding and on the other hand the absorbance of the hot combustion gas should be low (<0.1) in order to decrease the influence of the gas on the measured signal. This paper presents the results of the work performed by the authors with focus on the implementation of the LWIR pyrometer and the

  15. The Pulsair-Keeler non-contact tonometer in self-tonometry: preliminary results.

    Science.gov (United States)

    Boles Carenini, B; Brogliatti, B; Tonetto, C; Renis, E

    1992-09-01

    The authors considered the possibility of using the Pulsair-Keeler non-contact tonometer in self-tonometry. For this reason, 45 patients have been trained to use the instrument and, after a reasonable trial period, were able to self-measure their IOP. The results have been compared to the tonometric values measured with Goldmann tonometer to evaluate statistically the limits and the dependability of this method of measurement. The results shows that self-tonometry with the Pulsair-Keeler tonometer can be used in monitoring glaucomatous patients at home.

  16. [Principle and results of a new "non-contact-tonometer" are discussed (author's transl)].

    Science.gov (United States)

    Draeger, J; Jessen, K; Haselmann, G

    1975-07-01

    Comparing measurements with Non-Contact-Tonometer and handapplanation tonometer on 462 eyes with normal and elevated intraocular tension are statistically evaluated. The 2-s-limits for normal i.o. pressure at +/- 6.52 mm Hg (+/- 8.6 mbar), for elevated intraocular pressure +/- 13.2 mm Hg (+/- 17.6 mbar). This means less reliability than conventional applanation tonometers or even Schiötz-tonometers. The unability to read the tension when the corneal surface is rough means remarkable disadvantages to clinical use.

  17. Studies of non-contact methods for roughness measurements on wood surfaces

    International Nuclear Information System (INIS)

    Lundberg, I.A.S.; Porankiewicz, B.

    1995-01-01

    The quality of wood surfaces after different kinds of machining processes is a property of great importance for the wood processing industries. Present work is a study, whose objective was to evaluate different non-contact methods, for measurement of the quality of the wood surfaces by correlating them with stylus tracing. A number of Scots Pine samples were prepared by different kinds of wood machining processing. Surface roughness measurements were performed, utilizing two optical noncontact methods. The results indicate that the laser scan method can measure surface roughness on sawn wood with a sufficient degree of accuracy. (author) [de

  18. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography

    Directory of Open Access Journals (Sweden)

    Buj C.

    2015-09-01

    Full Text Available A very fast innovative holographic off-axis non-contact detection method for Photoacoustic Tomography (PAT is introduced. It overcomes the main problems of most state-of-the-art photoacoustic imaging approaches that are long acquisition times and the requirement of acoustic contact. In order to increase the acquisition speed significantly, the surface displacements of the object, caused by the photoacoustic pressure waves, are measured interferometrically in two dimensions. Phase alterations in the observed speckle field are used to identify changes in the object’s topography. A sampling rate of up to 80 MHz is feasible, which reduces the occurrence of motion artefacts.

  19. A descrição do funcionamento de um motor Homopolar linear e suas aplicações: Ilustrando o funcionamento de um acelerador de partículas

    OpenAIRE

    Doff, Adriano; Szmoski, Romeu M.

    2016-01-01

    Neste trabalho exploramos o potencial didático de um motor homopolar linear com o objetivo de ilustrar o princípio de funcionamento de um acelerador de partículas. A fim de estabelecer o mecanismo de funcionamento de um motor homopolar linear, consideramos uma analogia com a descrição de um motor homopolar rotatório, e partir deste apresentamos os princípios de funcionamento deste dispositivo e estabelecemos um limite teórico para a velocidade do motor linear. De posse dos dados gerados exper...

  20. Entropic potential field formed for a linear-motor protein near a filament: Statistical-mechanical analyses using simple models.

    Science.gov (United States)

    Amano, Ken-Ichi; Yoshidome, Takashi; Iwaki, Mitsuhiro; Suzuki, Makoto; Kinoshita, Masahiro

    2010-07-28

    We report a new progress in elucidating the mechanism of the unidirectional movement of a linear-motor protein (e.g., myosin) along a filament (e.g., F-actin). The basic concept emphasized here is that a potential field is entropically formed for the protein on the filament immersed in solvent due to the effect of the translational displacement of solvent molecules. The entropic potential field is strongly dependent on geometric features of the protein and the filament, their overall shapes as well as details of the polyatomic structures. The features and the corresponding field are judiciously adjusted by the binding of adenosine triphosphate (ATP) to the protein, hydrolysis of ATP into adenosine diphosphate (ADP)+Pi, and release of Pi and ADP. As the first step, we propose the following physical picture: The potential field formed along the filament for the protein without the binding of ATP or ADP+Pi to it is largely different from that for the protein with the binding, and the directed movement is realized by repeated switches from one of the fields to the other. To illustrate the picture, we analyze the spatial distribution of the entropic potential between a large solute and a large body using the three-dimensional integral equation theory. The solute is modeled as a large hard sphere. Two model filaments are considered as the body: model 1 is a set of one-dimensionally connected large hard spheres and model 2 is a double helical structure formed by two sets of connected large hard spheres. The solute and the filament are immersed in small hard spheres forming the solvent. The major findings are as follows. The solute is strongly confined within a narrow space in contact with the filament. Within the space there are locations with sharply deep local potential minima along the filament, and the distance between two adjacent locations is equal to the diameter of the large spheres constituting the filament. The potential minima form a ringlike domain in model 1

  1. A clinical comparison of the Xpert non-contact tonometer with the Goldmann applanation tonometer after penetrating keratoplasty.

    Science.gov (United States)

    Lisle, C; Ehlers, N

    2000-04-01

    To assess the agreement between the Xpert non-contact tonometer (NCT) and the Goldmann applanation tonometer in patients who have undergone penetrating keratoplasty. The study material consisted of 42 consecutive patients (43 eyes) who had undergone penetrating keratoplasty within the previous 13 months. The slope of the linear relationship between the two measurement methods did not differ significantly from 1.0. The mean difference between the methods of 0.96 mmHg was not statistically significant. The range of intraindividual differences between the methods was from -9.8 to 22.8 mmHg. The standard deviation of differences was 6.62 mmHg. The 95% limits of agreement were -12.00 to 13.94 mmHg. There was no significant correlation between the central corneal thickness, astigmatism or transplant size and the difference between the methods The Xpert NCT shows considerable variation from the Goldmann values The degree of agreement with the true IOP value remains to be shown.

  2. Proposal of Non-Contact Type Interface of Command Input Using Lip Motion Features

    Science.gov (United States)

    Sato, Yoshiyuki; Kageyama, Yoichi; Nishida, Makoto

    Lip motion features are of practical use in identifying individuals. It is therefore important to develop non-contact type interface. For the interface using lip motion features, individual differences such as accents and dialects in commands should be accepted. In this paper, we propose a method to identify commands by analyzing three kinds of lip motion features. They are lip width, lip length, and ratio of width and length. The analysis is made on the basis of these features' relative values obtained from the primary and object frame. The proposed method has three steps. First, we extracted the lip motion features on the basis of both positions and shapes of lip in each frame of facial images. Second, standard patterns were created from features of six utterances per command. The standard pattern is able to reduce the relative difference in the lip motion features. Third, similarities among commands were computed by Dynamic-Programming (DP) matching. And then, the command with the largest similarity was selected as the target one. Our experimental results suggest that proposed method is useful to construct the non-contact type interface of command input using lip motion features.

  3. Image-based non-contact monitoring of skin texture changed by piloerection for emotion estimation

    Science.gov (United States)

    Uchida, Mihiro; Akaho, Rina; Ogawa, Keiko; Tsumura, Norimichi

    2018-02-01

    In this paper, we find the effective feature values of skin textures captured by non-contact camera to monitor piloerection on the skin for emotion estimation. Recently, emotion estimation is required for service robots to interact with human more naturally. There are a lot of researches of estimating emotion and additional methods are required to improve emotion estimation because using only a few methods may not give enough information for emotion estimation. In the previous study, it is necessary to fix a device on the subject's arm for detecting piloerection, but the contact monitoring can be stress itself and distract the subject from concentrating in the stimuli and evoking strong emotion. So, we focused on the piloerection as the object obtained with non-contact methods. The piloerection is observed as goose bumps on the skin when the subject is emotionally moved, scared and so on. This phenomenon is caused by contraction of arrector pili muscles with the activation of sympathetic nervous system. This piloerection changes skin texture. Skin texture is important in the cosmetic industry to evaluate skin condition. Therefore, we thought that it will be effective to evaluate the condition of skin texture for emotion estimation. The evaluations were performed by extracting the effective feature values from skin textures captured with a high resolution camera. The effective feature values should have high correlation with the degree of piloerection. In this paper, we found that standard deviation of short-line inclination angles in the texture is well correlated with the degree of piloerection.

  4. A Case of Non-Contact Lens related Acanthamoeba keratitis in Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamed Kamel, A. G.

    2005-01-01

    Full Text Available Acanthamoeba is a ubiquitous free-living amoeba and is responsible for an uncommon yet increasingly diagnosed keratitis in humans. Acanthamoeba keratitis is perhaps the most challenging ocular infection to manage successfully and it can result in permanently impaired vision or blindness. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Cases of Acanthamoeba keratitis involving contact lens wearers have previously been reported in Malaysia but this is the first time, a non-contact lens relatedAcanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye. While working his eye was struck by some sand and dust particles and he quickly washed his eye with water from an open tank at the construction site. He then experienced pain, redness, glaring and blurring of vision of the right eye. The diagnosis was missed at the initial presentation but subsequent culture of the corneal scraping demonstrated Acanthamoeba as the aetiological agent. The history, clinical findings, diagnosis and treatment of non-contact lens related Acanthamoeba keratitis are briefly discussed in this communication. We hope to create awareness especially among the medical and paramedical staff about the existence of this infection in the country and fully support the consideration of Acanthamoeba keratitis as part of the differential diagnosis of most cases of presumed microbial keratitis.

  5. Non-contact assessment of obstructive sleep apnea cardiovascular biomarkers using photoplethysmography imaging

    Science.gov (United States)

    Amelard, Robert; Pfisterer, Kaylen J.; Jagani, Shubh; Clausi, David A.; Wong, Alexander

    2018-02-01

    Obstructive sleep apnea (OSA) affects 20% of the adult population, and is associated with cardiovascular and cognitive morbidities. However, it is estimated that up to 80% of treatable OSA cases remain undiagnosed. Cur- rent methods for diagnosing OSA are expensive, labor-intensive, and involve uncomfortable wearable sensors. This study explored the feasibility of non-contact biophotonic assessment of OSA cardiovascular biomarkers via photoplethysmography imaging (PPGI). In particular, PPGI was used to monitor the hemodynamic response to obstructive respiratory events. Sleep apnea onset was simulated using Muller's maneuver in which breathing was obstructed by a respiratory clamp. A custom PPGI system, coded hemodynamic imaging (CHI), was positioned 1 m above the bed and illuminated the participant's head with 850 nm light, providing non-intrusive illumination for night-time monitoring. A video was recorded before, during and following an apnea event at 60 fps, yielding 17 ms temporal resolution. Per-pixel absorbance signals were extracted using a Beer-Lambert derived light transport model, and subsequently denoised. The extracted hemodynamic signal exhibited dynamic temporal modulation during and following the apnea event. In particular, the pulse wave amplitude (PWA) decreased during obstructed breathing, indicating vasoconstriction. Upon successful inhalation, the PWA gradually increased toward homeostasis following a temporal phase delay. This temporal vascular tone modulation provides insight into autonomic and vascular response, and may be used to assess sleep apnea using non-contact biophotonic imaging.

  6. Non-contact assessment of electrical performance for rapidly sintered nanoparticle silver coatings through colorimetry

    International Nuclear Information System (INIS)

    Cherrington, M.; Claypole, T.C.; Gethin, D.T.; Worsley, D.A.; Deganello, D.

    2012-01-01

    The color change during the ultrafast near-infrared sintering process of a nanoparticle silver ink has been correlated to its electrical performance through colorimetry using the CIELAB industry standard. Nanoparticle silver ink films, deposited over a flexible polyethylene terephthalate substrate, presented significant shifting in the a* and b* color coordinates during sintering, exhibiting the best conductivity with an a* coordinate of approximately 0 and a b* coordinate of approximately + 10. This color change has been associated with the Lorenz–Mie theory of electromagnetic scattering. This indirect measurement technique is potentially a breakthrough technology for fast in-line non-contact characterization of the drying and sintering process of nanoparticle conductive inks for use in large area roll-to-roll processing of printed electronics. - Highlights: ► Color change of a nanoparticle silver coating was measured during sintering ► Color change was correlated to the electrical performance of the coating. ► Potential in-line non-contact measurement method for roll-to-roll printed electronics

  7. Non-contact assessment of electrical performance for rapidly sintered nanoparticle silver coatings through colorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cherrington, M.; Claypole, T.C.; Gethin, D.T. [Welsh Centre for Printing and Coating, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Worsley, D.A. [SPECIFIC, College of Engineering, Swansea University, Baglan Bay Innovation Centre, Central Avenue, Baglan Energy Park, Port Talbot, SA12 7AX (United Kingdom); Deganello, D., E-mail: d.deganello@swansea.ac.uk [Welsh Centre for Printing and Coating, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)

    2012-11-01

    The color change during the ultrafast near-infrared sintering process of a nanoparticle silver ink has been correlated to its electrical performance through colorimetry using the CIELAB industry standard. Nanoparticle silver ink films, deposited over a flexible polyethylene terephthalate substrate, presented significant shifting in the a* and b* color coordinates during sintering, exhibiting the best conductivity with an a* coordinate of approximately 0 and a b* coordinate of approximately + 10. This color change has been associated with the Lorenz-Mie theory of electromagnetic scattering. This indirect measurement technique is potentially a breakthrough technology for fast in-line non-contact characterization of the drying and sintering process of nanoparticle conductive inks for use in large area roll-to-roll processing of printed electronics. - Highlights: Black-Right-Pointing-Pointer Color change of a nanoparticle silver coating was measured during sintering Black-Right-Pointing-Pointer Color change was correlated to the electrical performance of the coating. Black-Right-Pointing-Pointer Potential in-line non-contact measurement method for roll-to-roll printed electronics.

  8. Non-Contact Smartphone-Based Monitoring of Thermally Stressed Structures

    Science.gov (United States)

    Ozturk, Turgut; Mas, David; Rizzo, Piervincenzo

    2018-01-01

    The in-situ measurement of thermal stress in beams or continuous welded rails may prevent structural anomalies such as buckling. This study proposed a non-contact monitoring/inspection approach based on the use of a smartphone and a computer vision algorithm to estimate the vibrating characteristics of beams subjected to thermal stress. It is hypothesized that the vibration of a beam can be captured using a smartphone operating at frame rates higher than conventional 30 Hz, and the first few natural frequencies of the beam can be extracted using a computer vision algorithm. In this study, the first mode of vibration was considered and compared to the information obtained with a conventional accelerometer attached to the two structures investigated, namely a thin beam and a thick beam. The results show excellent agreement between the conventional contact method and the non-contact sensing approach proposed here. In the future, these findings may be used to develop a monitoring/inspection smartphone application to assess the axial stress of slender structures, to predict the neutral temperature of continuous welded rails, or to prevent thermal buckling. PMID:29670034

  9. Clinical performance of the Reichert AT550: a new non-contact tonometer.

    Science.gov (United States)

    Jorge, J; Díaz-Rey, J A; González-Méijome, J M; Almeida, J B; Parafita, M A

    2002-11-01

    The aim of the present study was to assess the level of accuracy for measurements of intra-ocular pressure (IOP) obtained with a new non-contact tonometer (NCT) the Reichert AT550. Measurements were compared against those obtained with the Reichert Xpert Plus, Goldmann applanation tonometer and Perkins tonometer. Thirty-five university students were assessed with the four tonometers in a randomised order, with non-contact tonometry performed first. Each of the four measurement devices had its own trained clinical observer. Plots of differences of IOP as a function of the mean for each pair of instruments were obtained. No statistically significant differences were found when comparing the AT550 NCT with contact applanation tonometry (AT) (p> 0.05), displaying the closest level of agreement (as represented by the lowest mean difference and the narrowest confidence interval) with the Goldmann tonometer (limits of agreement, 0.12+/-2.17). In conclusion, readings of IOP with the AT550 NCT are clinically comparable with those obtained with Goldmann tonometry in a population with IOP within the normal range.

  10. Smart Garment Fabrics to Enable Non-Contact Opto-Physiological Monitoring.

    Science.gov (United States)

    Iakovlev, Dmitry; Hu, Sijung; Hassan, Harnani; Dwyer, Vincent; Ashayer-Soltani, Roya; Hunt, Chris; Shen, Jinsong

    2018-03-29

    Imaging photoplethysmography (iPPG) is an emerging technology used to assess microcirculation and cardiovascular signs by collecting backscattered light from illuminated tissue using optical imaging sensors. The aim of this study was to study how effective smart garment fabrics could be capturing physiological signs in a non-contact mode. The present work demonstrates a feasible approach of, instead of using conventional high-power illumination sources, integrating a grid of surface-mounted light emitting diodes (LEDs) into cotton fabric to spotlight the region of interest (ROI). The green and the red LEDs (525 and 660 nm) placed on a small cotton substrate were used to locally illuminate palm skin in a dual-wavelength iPPG setup, where the backscattered light is transmitted to a remote image sensor through the garment fabric. The results show that the illuminations from both wavelength LEDs can be used to extract heart rate (HR) reaching an accuracy of 90% compared to a contact PPG probe. Stretching the fabric over the skin surface alters the morphology of iPPG signals, demonstrating a significantly higher pulsatile amplitude in both channels of green and red illuminations. The skin compression by the fabric could be potentially utilised to enhance the penetration of illumination into cutaneous microvascular beds. The outcome could lead a new avenue of non-contact opto-physiological monitoring and assessment with functional garment fabrics.

  11. Development of Non-contact Respiratory Monitoring System for Newborn Using a FG Vision Sensor

    Science.gov (United States)

    Kurami, Yoshiyuki; Itoh, Yushi; Natori, Michiya; Ohzeki, Kazuo; Aoki, Yoshimitsu

    In recent years, development of neonatal care is strongly hoped, with increase of the low-birth-weight baby birth rate. Especially respiration of low-birth-weight baby is incertitude because central nerve and respiratory function is immature. Therefore, a low-birth-weight baby often causes a disease of respiration. In a NICU (Neonatal Intensive Care Unit), neonatal respiration is monitored using cardio-respiratory monitor and pulse oximeter at all times. These contact-type sensors can measure respiratory rate and SpO2 (Saturation of Peripheral Oxygen). However, because a contact-type sensor might damage the newborn's skin, it is a real burden to monitor neonatal respiration. Therefore, we developed the respiratory monitoring system for newborn using a FG (Fiber Grating) vision sensor. FG vision sensor is an active stereo vision sensor, it is possible for non-contact 3D measurement. A respiratory waveform is calculated by detecting the vertical motion of the thoracic and abdominal region with respiration. We attempted clinical experiment in the NICU, and confirmed the accuracy of the obtained respiratory waveform was high. Non-contact respiratory monitoring of newborn using a FG vision sensor enabled the minimally invasive procedure.

  12. A method of non-contact reading code based on computer vision

    Science.gov (United States)

    Zhang, Chunsen; Zong, Xiaoyu; Guo, Bingxuan

    2018-03-01

    With the purpose of guarantee the computer information exchange security between internal and external network (trusted network and un-trusted network), A non-contact Reading code method based on machine vision has been proposed. Which is different from the existing network physical isolation method. By using the computer monitors, camera and other equipment. Deal with the information which will be on exchanged, Include image coding ,Generate the standard image , Display and get the actual image , Calculate homography matrix, Image distort correction and decoding in calibration, To achieve the computer information security, Non-contact, One-way transmission between the internal and external network , The effectiveness of the proposed method is verified by experiments on real computer text data, The speed of data transfer can be achieved 24kb/s. The experiment shows that this algorithm has the characteristics of high security, fast velocity and less loss of information. Which can meet the daily needs of the confidentiality department to update the data effectively and reliably, Solved the difficulty of computer information exchange between Secret network and non-secret network, With distinctive originality, practicability, and practical research value.

  13. Features of the non-contact carotid pressure waveform: Cardiac and vascular dynamics during rebreathing

    Science.gov (United States)

    Casaccia, S.; Sirevaag, E. J.; Richter, E. J.; O'Sullivan, J. A.; Scalise, L.; Rohrbaugh, J. W.

    2016-10-01

    This report amplifies and extends prior descriptions of the use of laser Doppler vibrometry (LDV) as a method for assessing cardiovascular activity, on a non-contact basis. A rebreathing task (n = 35 healthy individuals) was used to elicit multiple effects associated with changes in autonomic drive as well as blood gases including hypercapnia. The LDV pulse was obtained from two sites overlying the carotid artery, separated by 40 mm. A robust pulse signal was obtained from both sites, in accord with the well-described changes in carotid diameter over the blood pressure cycle. Emphasis was placed on extracting timing measures from the LDV pulse, which could serve as surrogate measures of pulse wave velocity (PWV) and the associated arterial stiffness. For validation purposes, a standard measure of pulse transit time (PTT) to the radial artery was obtained using a tonometric sensor. Two key measures of timing were extracted from the LDV pulse. One involved the transit time along the 40 mm distance separating the two LDV measurement sites. A second measure involved the timing of a late feature of the LDV pulse contour, which was interpreted as reflection wave latency and thus a measure of round-trip travel time. Both LDV measures agreed with the conventional PTT measure, in disclosing increased PWV during periods of active rebreathing. These results thus provide additional evidence that measures based on the non-contact LDV technique might provide surrogate measures for those obtained using conventional, more obtrusive assessment methods that require attached sensors.

  14. POLYELECTROLYTE MULTILAYER STAMPING IN AQUEOUS PHASE AND NON-CONTACT MODE

    Science.gov (United States)

    Mehrotra, Sumit; Lee, Ilsoon; Liu, Chun; Chan, Christina

    2011-01-01

    Polyelectrolyte multilayer (PEM) transfer printing has been previously achieved by stamping under dry conditions. Here, we show for the first time, that PEM can be transferred from a stamp to the base substrate under aqueous conditions whereby the two surfaces are in a non-contact mode. Degradable multilayers of (PAA/PEG)10.5 followed by non-degradable multilayers of (PDAC/SPS)80.5 were fabricated under acidic pH conditions on either PDMS or glass (stamp), and subsequently transferred over top of another multilayer prepared on a different substrate (base substrate), with a spacing of ~ 200 μm between the stamping surface and the base substrate. This multilayer transfer was performed under physiological pH conditions. This process is referred to herein as non-contact, aqueous-phase multilayer (NAM) transfer. NAM transfer can be useful for applications such as fabricating three-dimensional (3-D) cellular scaffolds. We attempted to create a 3-D cellular scaffold using NAM transfer, and characterized the scaffolds with conventional and fluorescence microscopy. PMID:21860540

  15. Design of novel non-contact multimedia controller for disability by using visual stimulus.

    Science.gov (United States)

    Pan, Jeng-Shyang; Lo, Chi-Chun; Tsai, Shang-Ho; Lin, Bor-Shyh

    2015-12-01

    The design of a novel non-contact multimedia controller is proposed in this study. Nowadays, multimedia controllers are generally used by patients and nursing assistants in the hospital. Conventional multimedia controllers usually involve in manual operation or other physical movements. However, it is more difficult for the disabled patients to operate the conventional multimedia controller by themselves; they might totally depend on others. Different from other multimedia controllers, the proposed system provides a novel concept of controlling multimedia via visual stimuli, without manual operation. The disabled patients can easily operate the proposed multimedia system by focusing on the control icons of a visual stimulus device, where a commercial tablet is used as the visual stimulus device. Moreover, a wearable and wireless electroencephalogram (EEG) acquisition device is also designed and implemented to easily monitor the user's EEG signals in daily life. Finally, the proposed system has been validated. The experimental result shows that the proposed system can effectively measure and extract the EEG feature related to visual stimuli, and its information transfer rate is also good. Therefore, the proposed non-contact multimedia controller exactly provides a good prototype of novel multimedia controlling scheme. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Microfluidic impact printer with interchangeable cartridges for versatile non-contact multiplexed micropatterning.

    Science.gov (United States)

    Ding, Yuzhe; Huang, Eric; Lam, Kit S; Pan, Tingrui

    2013-05-21

    Biopatterning has been increasingly used for well-defined cellular microenvironment, patterned surface topology, and guided biological cues; however, it meets challenges on biocompatibility, thermal and chemical sensitivity, as well as limited availability of reagents. In this paper, we aim at combining the desired features from non-contact inkjet printing and dot-matrix impact printing to establish a versatile multiplexed micropatterning platform, referred to as Microfluidic Impact Printer (MI-Printer), for emerging biomedical applications. Using this platform, we can achieve the distinct features of no cross-contamination, sub-microliter ink loading with a minimal dead volume, high-throughput printing, biocompatible non-contact processing, sequential patterning with self-alignment, wide adaptability for complex media (e.g., cell suspension or colloidal solutions), interchangeable/disposable cartridge design, and simple assembly and configuration, all highly desirable towards laboratory-based research and development. Specifically, the printing resolution of the MI-printer platform has been experimentally characterized and theoretically analysed. Optimal printing resolution of 80 μm has been repeatedly obtained. Furthermore, two useful functions of the MI-printer, multiplexed printing and combinatorial printing, have been experimentally demonstrated with less than 10 μm misalignment. Moreover, molecular and biological patterning, utilizing the multiplexed and combinatorial printing, has been implemented to illustrate the utility of this versatile printing technique for emerging biomedical applications.

  17. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland [Institute of Materials Physics, Graz University of Technology, A-8010 Graz (Austria)

    2016-07-15

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  18. Diode laser-induced tissue effects: in vitro tissue model study and in vivo evaluation of wound healing following non-contact application.

    Science.gov (United States)

    Havel, Miriam; Betz, Christian S; Leunig, Andreas; Sroka, Ronald

    2014-08-01

    The basic difference between the various common medical laser systems is the wavelength of the emitted light, leading to altered light-tissue interactions due to the optical parameters of the tissue. This study examines laser induced tissue effects in an in vitro tissue model using 1,470 nm diode laser compared to our standard practice for endonasal applications (940 nm diode laser) under standardised and reproducible conditions. Additionally, in vivo induced tissue effects following non-contact application with focus on mucosal healing were investigated in a controlled intra-individual design in patients treated for hypertrophy of nasal turbinate. A certified diode laser system emitting the light of λ = 1470 nm was evaluated with regards to its tissue effects (ablation, coagulation) in an in vitro setup on porcine liver and turkey muscle tissue model. To achieve comparable macroscopic tissue effects the laser fibres (600 µm core diameter) were fixed to a computer controlled stepper motor and the laser light was applied in a reproducible procedure under constant conditions. For the in vivo evaluation, 20 patients with nasal obstruction due to hyperplasia of inferior nasal turbinates were included in this prospective randomised double-blinded comparative trial. The endoscopic controlled endonasal application of λ = 1470 nm on the one and λ = 940 nm on the other side, both in 'non-contact' mode, was carried out as an outpatient procedure under local anaesthesia. The postoperative wound healing process (mucosal swelling, scab formation, bleeding, infection) was endoscopically documented and assessed by an independent physician. In the experimental setup, the 1,470 nm laser diode system proved to be efficient in inducing tissue effects in non-contact mode with a reduced energy factor of 5-10 for highly perfused liver tissue to 10-20 for muscle tissue as compared to the 940 nm diode laser system. In the in vivo evaluation scab formation

  19. Dynamic modeling and simulation of an induction motor with adaptive backstepping design of an input-output feedback linearization controller in series hybrid electric vehicle

    Directory of Open Access Journals (Sweden)

    Jalalifar Mehran

    2007-01-01

    Full Text Available In this paper using adaptive backstepping approach an adaptive rotor flux observer which provides stator and rotor resistances estimation simultaneously for induction motor used in series hybrid electric vehicle is proposed. The controller of induction motor (IM is designed based on input-output feedback linearization technique. Combining this controller with adaptive backstepping observer the system is robust against rotor and stator resistances uncertainties. In additional, mechanical components of a hybrid electric vehicle are called from the Advanced Vehicle Simulator Software Library and then linked with the electric motor. Finally, a typical series hybrid electric vehicle is modeled and investigated. Various tests, such as acceleration traversing ramp, and fuel consumption and emission are performed on the proposed model of a series hybrid vehicle. Computer simulation results obtained, confirm the validity and performance of the proposed IM control approach using for series hybrid electric vehicle.

  20. The Multiple Correspondence Analysis Method and Brain Functional Connectivity: Its Application to the Study of the Non-linear Relationships of Motor Cortex and Basal Ganglia.

    Science.gov (United States)

    Rodriguez-Sabate, Clara; Morales, Ingrid; Sanchez, Alberto; Rodriguez, Manuel

    2017-01-01

    The complexity of basal ganglia (BG) interactions is often condensed into simple models mainly based on animal data and that present BG in closed-loop cortico-subcortical circuits of excitatory/inhibitory pathways which analyze the incoming cortical data and return the processed information to the cortex. This study was aimed at identifying functional relationships in the BG motor-loop of 24 healthy-subjects who provided written, informed consent and whose BOLD-activity was recorded by MRI methods. The analysis of the functional interaction between these centers by correlation techniques and multiple linear regression showed non-linear relationships which cannot be suitably addressed with these methods. The multiple correspondence analysis (MCA), an unsupervised multivariable procedure which can identify non-linear interactions, was used to study the functional connectivity of BG when subjects were at rest. Linear methods showed different functional interactions expected according to current BG models. MCA showed additional functional interactions which were not evident when using lineal methods. Seven functional configurations of BG were identified with MCA, two involving the primary motor and somatosensory cortex, one involving the deepest BG (external-internal globus pallidum, subthalamic nucleus and substantia nigral), one with the input-output BG centers (putamen and motor thalamus), two linking the input-output centers with other BG (external pallidum and subthalamic nucleus), and one linking the external pallidum and the substantia nigral. The results provide evidence that the non-linear MCA and linear methods are complementary and should be best used in conjunction to more fully understand the nature of functional connectivity of brain centers.

  1. Comparative study of intraocular pressure (IP in Bangladeshi individuals by contact and non contact technique

    Directory of Open Access Journals (Sweden)

    Sayed Abdul Wadud

    2016-07-01

    Full Text Available Background: Intraocular pressure (IOP is one of the most important parameters in the diagnosis and treatment of glaucoma. Glaucoma has been established as the second leading cause of blindness. The treatment of glaucoma focuses mainly on lowering intraocular pressure (IOP. The target IOP is often set to a level 20% to 30% of IOP reduction, and consequent large IOP reduction beyond 30% or even 40% in cases of advanced glaucoma The different methods of tonometery are: Goldman Applanation tonometery, Noncontact (air-puff tonometery, Perkins tonometery, Tonopen tonometery, Transpalpebral tonometery.Objective: To determine the frequency of accuracy of intraocular pressure (IOP measured by non-contact (air puff tonometer compared with Goldmann applanation tonometer.Methods: This was a non-interventional, cross sectional study conducted at a tertiary care centre of Dhaka, Bangladesh. consecutive subjects attending the BSMMU eye OPD were included in the study. IOP was measured by non-contact (air puff tonometer and a slit lamp mounted GAT in all the subjects. The study samples were selected by convenience sampling who presented for check-up in the Eye Department of community ophthalmology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Bangladesh. Results:A total of 120 eyes in 60 patients were studied. The mean age of the patients was 41.60 year. study population consisted of 24 (40 % men and 36 (60 % women. The mean intraocular pressure was 13.52 &13.72 mmHg for GAT, and 16.64 & 17.44 mmHg for Air puff respectively. The range of measurements by GAT was from 10 to 23 mmHg and by Air puff was 12 to 28mmHg. The difference between IOP measured by two instruments were statistically significant (p=0.000.Conclusion: Airpuff tonometer is quick, a non-contact method to measure intraocular pressure and is useful for screening purposes and postoperative case but the measurements should be confirmed with Goldmann applanation tonometer for accurate labelling

  2. Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis.

    Science.gov (United States)

    Sharma, S; Garg, P; Rao, G N

    2000-10-01

    To review the clinical characteristics, diagnosis, and visual outcome in patients with non-contact lens related Acanthamoeba keratitis and compare the findings with reported series of contact lens associated Acanthamoeba keratitis. Medical and microbiology records of 39 consecutive patients with a diagnosis of Acanthamoeba keratitis, at a tertiary eyecare centre in India between January 1996 and June 1998, were analysed retrospectively. A majority of the patients presented with poor visual acuity and large corneal stromal infiltrates (mean size 38.20 (SD 26. 18) mm). A predisposing factor was elicited in 19/39 (48.7%) patients (trauma 15, dirty water splash three, leaf juice one). None of the patients had worn contact lenses. Most patients (26/39 (66. 6%)) came from a low socioeconomic background. Complaint of severe pain was not a significant feature and radial keratoneuritis was seen in 1/39 (2.5%) patients. A ring infiltrate was present in 41.1% of cases. A clinical diagnosis of fungal keratitis was made in 45% of the patients before they were seen by us. However, all patients were diagnosed microbiologically at our institute based on demonstration of Acanthamoeba cysts in corneal scrapings (34/39) and/or culture of Acanthamoeba (34/39). Treatment with biguanides (PHMB, 15/38 (39.4%), PHMB with CHx, 23/38 (60.5%), one patient did not return for treatment) resulted in healing with scar formation in 27 out of 31(87.0%) followed up patients (mean time to healing 106.9 days). Overall visual outcome was poor with no statistical difference between cases diagnosed within 30 days (early) or 30 days after (late) start of symptoms. The visual outcome in cases requiring tissue adhesive (five) and keratoplasty (three) was also poor. This is thought to be the largest series of cases of Acanthamoeba keratitis in non-contact lens wearers. In such cases, the disease is advanced at presentation in most patients, pathognomonic clinical features are often not seen, disease

  3. Design elements and quantitative results of synchronous longstator linear motors for high-speed magnetic trains taking the TRANSRAPID test facility in Emsland as an example

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, R [Industrieanlagen-Betriebsgesellschaft mbH, Magnetbahn-Versuchsanlage, Lathen/Ems (Germany)

    1996-12-31

    In German high-speed magnetic train technology, iron-clad synchronous long-stator linear motors of levitation stator design are used to propel and brake the vehicles. This paper uses the propulsion design of the Transrapid test facility in Emsland (TVE) to illustrate in practical terms the dimensioning parameters for thrust calculations and their interdependencies. The paper is based on description conventions common for rotating electrical machines and rail technology. (orig.)

  4. Small-sized linear accelerator of 2.5 MeV electrons with a local radiation shield for custom examination of freight transported by motor transport

    International Nuclear Information System (INIS)

    Baklanov, A.V.; Gavrish, Yu.N.; Klinov, A.P.; Krest'yaninov, A.S.; Nikolaev, V.M.; Fomin, L.P.; Linkenbach, H.A.; Geus, G.; Knospel, W.

    2001-01-01

    A new development of a small-sized linear accelerator of 2.5 MeV electrons with a local radiation protection is described. The accelerator is intended for movable facilities of radiation custom of the freight transported by motor transport. Main constructive solutions, mass and dimension characteristics and results of preliminary tests of the accelerator parameters and characteristics of radiation protection are presented [ru

  5. Fluctuations in isometric muscle force can be described by one linear projection of low-frequency components of motor unit discharge rates.

    Science.gov (United States)

    Negro, Francesco; Holobar, Ales; Farina, Dario

    2009-12-15

    The aim of the study was to investigate the relation between linear transformations of motor unit discharge rates and muscle force. Intramuscular (wire electrodes) and high-density surface EMG (13 x 5 electrode grid) were recorded from the abductor digiti minimi muscle of eight healthy men during 60 s contractions at 5%, 7.5% and 10% of the maximal force. Spike trains of a total of 222 motor units were identified from the EMG recordings with decomposition algorithms. Principal component analysis of the smoothed motor unit discharge rates indicated that one component (first common component, FCC) described 44.2 +/- 7.5% of the total variability of the smoothed discharge rates when computed over the entire contraction interval and 64.3 +/- 10.2% of the variability when computed over 5 s intervals. When the FCC was computed from four or more motor units per contraction, it correlated with the force produced by the muscle (62.7 +/- 10.1%) by a greater degree (P FCC and the force signal increased up to 71.8 +/- 13.1% when the duration and the shape of the smoothing window for discharge rates were similar to the average motor unit twitch force. Moreover, the coefficients of variation (CoV) for the force and for the FCC signal were correlated in all subjects (R(2) range = 0.14-0.56; P measures on the tibialis anterior muscle of an additional eight subjects during contractions at forces up to 20% of the maximal force (e.g. FCC explained 59.8 +/- 11.0% of variability of the smoothed discharge rates). In conclusion, one signal captures most of the underlying variability of the low-frequency components of motor unit discharge rates and explains large part of the fluctuations in the motor output during isometric contractions.

  6. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    Science.gov (United States)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  7. A real-time non-contact monitoring method of subsea pipelines

    Directory of Open Access Journals (Sweden)

    Song Dalei

    2015-01-01

    Full Text Available To monitoring the subsea pipeline in real-time, a special potentiometric sensor array and a potential prediction model are presented in this paper. Firstly, to measure the potential of seawater, a special potentiometric sensor array with Ag/AgCl all-solid-state reference electrodes is first developed in this paper. Secondly, according to the obtained distribution law of electric field intensities a prediction model of the pipeline potentials is developed. Finally, the potentiometric sensor array is applied in sink experiment and the prediction model is validated by the sink measurements. The maximum error for pipeline potential prediction model is 1.1 mV. The proposed non-contact monitoring method for subsea pipeline can predict the potential of sea pipeline in real-time, thus providing important information for further subsea pipeline maintenance.

  8. Sub-Angstrom oscillation amplitude non-contact atomic force microscopy for lateral force gradient measurement

    International Nuclear Information System (INIS)

    Atabak, Mehrdad; Unverdi, Ozhan; Ozer, H. Ozguer; Oral, Ahmet

    2009-01-01

    We report the first results from novel sub-Angstrom oscillation amplitude non-contact atomic force microscopy developed for lateral force gradient measurements. Quantitative lateral force gradients between a tungsten tip and Si(1 1 1)-(7 x 7) surface can be measured using this microscope. Simultaneous lateral force gradient and scanning tunnelling microscope images of single and multi atomic steps are obtained. In our measurement, tunnel current is used as feedback. The lateral stiffness contrast has been observed to be 2.5 N/m at single atomic step, in contrast to 13 N/m at multi atomic step on Si(1 1 1) surface. We also carried out a series of lateral stiffness-distance spectroscopy. We observed lateral stiffness-distance curves exhibit sharp increase in the stiffness as the sample is approached towards the surface. We usually observed positive stiffness and sometimes going into slightly negative region.

  9. An infrared-driven flexible pyroelectric generator for non-contact energy harvester

    Science.gov (United States)

    Zhao, Tingting; Jiang, Weitao; Liu, Hongzhong; Niu, Dong; Li, Xin; Liu, Weihua; Li, Xuan; Chen, Bangdao; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2016-04-01

    In recent years, energy harvesting technologies, which can scavenge many kinds of energies from our living environment to power micro/nanodevices, have attracted increasing attention. However, remote energy transmission, flexibility and electric waveform controllability remain the key challenges for wireless power supply by an energy harvester. In this paper, we design a new infrared-driven non-contact pyroelectric generator for harvesting heat energy, which avoids direct contact between the pyroelectric generator and heat source and realizes remote energy transfer exploiting the photothermal and penetrability of infrared light. The output voltage (under the input impedance of 100 MOhm) and short-circuit current of the pyroelectric generator consisting of a CNT/PVDF/CNT layer (20 mm × 5 mm × 100 μm) can be as large as 1.2 V and 9 nA, respectively, under a 1.45 W cm-2 near-infrared laser (808 nm). We also demonstrate the means by which the pyroelectric generator can modulate square waveforms with controllable periods through irradiation frequency, which is essential for signal sources and medical stimulators. The overshoot of square waveforms are in a range of 9.0%-13.1% with a rise time of 120 ms. The prepared pyroelectric generator can light a liquid crystal display (LCD) in a vacuum chamber from outside. This work paves the way for non-contact energy harvesting for some particular occasions where near-field energy control is not available.In recent years, energy harvesting technologies, which can scavenge many kinds of energies from our living environment to power micro/nanodevices, have attracted increasing attention. However, remote energy transmission, flexibility and electric waveform controllability remain the key challenges for wireless power supply by an energy harvester. In this paper, we design a new infrared-driven non-contact pyroelectric generator for harvesting heat energy, which avoids direct contact between the pyroelectric generator and heat

  10. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system.

    Science.gov (United States)

    Johansson, Johannes D; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

    2016-02-01

    A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma.

  11. The non-contact ("air puff") tonometer: variability and corneal staining.

    Science.gov (United States)

    Myers, K J; Scott, C A

    1975-01-01

    We investigated the possibility of significant corneal trauma (as revealed by slit lamp observation of the fluorescein instilled eye), and massage effects following determination of intraocular pressure with the A. O. Non-Contact tonometer (NCT). Fifteen different, normal human eyes were each applanated 150 successive times with the NCT; leading to the conclusion that only minor, superficial corneal epithelial defects sometimes resulted and that, in line with other studies, the initially higher readings (about 1 mm), obtained with the NCT, were most likely due to patient apprehension, while the subsequently lower readings represented patient acceptance of the process and were not a result of true aqueous massage. As in an earlier study, we found the instrument's variability to be about plus and minus 1 or plus and minus 2 mm and probably due to the subject's own cardiac cycle.

  12. Plate-shaped non-contact ultrasonic transporter using flexural vibration.

    Science.gov (United States)

    Ishii, Takahiko; Mizuno, Yosuke; Koyama, Daisuke; Nakamura, Kentaro; Harada, Kana; Uchida, Yukiyoshi

    2014-02-01

    We developed a plate-shaped non-contact transporter based on ultrasonic vibration, exploiting a phenomenon that a plate can be statically levitated at the place where its gravity and the acoustic radiation force are balanced. In the experiment, four piezoelectric zirconate titanate elements were attached to aluminum plates, on which lattice flexural vibration was excited at 22.3 kHz. The vibrating plates were connected to a loading plate via flexible posts that can minimize the influence of the flexure induced by heavy loads. The distribution of the vibration displacement on the plate was predicted through finite-element analysis to find the appropriate positions of the posts. The maximum levitation height of this transporter was 256 μm with no load. When two vibrating plates were connected to a loading plate, the maximum transportable load was 4.0 kgf. Copyright © 2013. Published by Elsevier B.V.

  13. Investigation of human body potential measured by a non-contact measuring system.

    Science.gov (United States)

    Ichikawa, Norimitsu

    2016-12-07

    A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body's voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not.

  14. Non-contact micro mass evaluation method using an X-ray microscope

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jiseok; Sun, Gwang Min; Baek, Ha Ni; Hoang, Sy Minh Tuan; Park, Sun Ae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-07-15

    For the mass inspection of attached foils such as printed electrodes, mass should be measured by a non-contact method with the capacity to measure a small mass of micrograms. In this study, the masses of 1 mg to 10 mg electrodes were evaluated using an X-ray microscope. The results were compared with the masses determined by using a digital scale with a 0.005 mg error. The average of the relative error between the mass measurements using the X-ray microscope and those using the digital scale was less than 2.51%. The results show that X-ray mass evaluation method can be used for mass measurement of micro objects by replacing a digital scale.

  15. Non-Contact Monitoring of Heart and Lung Activity by Magnetic Induction Measurement

    Directory of Open Access Journals (Sweden)

    M. Steffen

    2008-01-01

    Full Text Available In many clinical applications, the monitoring of heart and lung activity is of vital importance. State-of-the-art monitoring involves the use of electrodes or other contact based sensors (electrocardiogram (ECG, impedance cardiography (ICG, pulse oximetry or equivalent. With the equipment that is used, side effects like skin irritation, difficult application or additional cabling may occur. In contrast, this paper describes a method for non-contact monitoring of heart and lung activity, which is solely based on magnetic induction. This method allows simultaneous monitoring of heart and lung activity, and has the potential of an integrated application in a personal healthcare scenario. To illustrate the performance, a simple test-setup has been developed and the first results are presented here (some of which have been previously presented on the Poster 2008 [10]. 

  16. A Study on non-contact measurements of laser-generated lamb waves

    International Nuclear Information System (INIS)

    Jang, Tae Seong; Lee, Jung Ju; Lee, Seung Seok

    2002-01-01

    Generation and detection of Lamb waves offer an effective non-destructive testing technique that will detect defects quickly and reliably. Lamb waves are generated in a thin plate by Q-switched Nd:YAG pulsed laser. Symmetric and antisymmetric Lamb modes in low-frequency-thickness regime are excited by illuminating a thin plate with an array of laser-generated line sources. The propagation of laser-generated Lamb waves is detected by measuring the out-of-plane displacements in a non-contact manner using the fiber optic Sagnac interferometer and all commercial adaptive reference-beam interferometer. The characteristics of laser-generated Lamb wave due to its frequency are investigated. Fundamental understanding of laser-generated Lamb modes is presented.

  17. Investigation of the Sintering Process Using Non-Contact Electromagnetic Acoustic Transducers

    International Nuclear Information System (INIS)

    James C. Foley; David K. Rehbein; Daniel J. Barnard

    2001-01-01

    In-situ characterizations of green state part density and sintering state have long been desired in the powder metal community. Recent advances in non-contact electromagnetic acoustic transducer (EMAT) technology have enabled in-situ monitoring of acoustic amplitude and velocity as sintering proceeds. Samples were made from elemental powders of Al (99.99%), Al (99.7%), Ag, (99.99%), Cu (99.99%) and Fe (99.9%). The powders were pressed in a uniaxial die and examined with acoustic waves for changes in velocity and amplitude during sintering for the samples containing Al, Ag, and Cu. The changes in acoustic properties were correlated with sample microstructures and mechanical properties. Evolution of a series of reverberating echoes during sintering is shown to provide information on the state of sintering, and changes in sintering kinetics as well as having the potential for detection of interior flaws

  18. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    International Nuclear Information System (INIS)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-01-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants

  19. Non-Contact Thickness and Profile Measurements of Rolled Aluminium Strip Using EMAT

    International Nuclear Information System (INIS)

    Hobbis, A.; Aruleswaran, A.

    2006-01-01

    Accurate measurement of strip thickness is a very high priority for the aluminium rolled product industry. This paper presents the findings of trials to measure the thickness of aluminium strip using a send-receive, radially polarised Electromagnetic Acoustic Transducer (EMAT). A broadband EMAT system, developed at Warwick University, UK with a centre frequency of approximately 5 MHz and frequency content up to 12 MHz was used. The resultant ultrasonic waveforms have been processed using Fourier analysis. Static measurements of aluminium alloy samples in the thickness range between 0.28 mm to 2.8 mm have been measured using this non-contact approach at stand-offs of up to 2 mm. Measurements across the aluminium strip width to evaluate its profile for quality control was also carried out successfully. Some of the experiments and results obtained are described in detail

  20. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury

    DEFF Research Database (Denmark)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars Louis

    2016-01-01

    phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. METHODS: Sixty-two adolescent female elite......BACKGROUND: Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular...... football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored...

  1. Non-contact optical sensor for detection of glucose concentration using a magneto-optic effect

    Science.gov (United States)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; García, Javier; Zalevsky, Zeev

    2016-03-01

    In this paper we aim to experimentally verify a speckle based technique for non-contact measurement of glucose concentration in blood stream while the vision for the final device aims to contain a single wristwatch-style device containing an AC (alternating) electro-magnet generated by a solenoid, a laser and a camera. The experiments presented in work are performed in-vitro in order to verify the effects that are responsible for the operation principle. When a glucose substance is inserted into a solenoid generating an alternating magnetic field it exhibits Faraday rotation which affects the temporal changes of the secondary speckle patterns distribution. The temporal frequency resulting from the AC magnetic field was found to have a lock-in amplification role which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  2. Non-contact measurements of creep properties of niobium at 1985 °C

    Science.gov (United States)

    Lee, J.; Wall, J. J.; Rogers, J. R.; Rathz, T. J.; Choo, H.; Liaw, P. K.; Hyers, R. W.

    2015-01-01

    The stress exponent in the power-law creep of niobium at 1985 °C was measured by a non-contact technique using an electrostatic levitation facility at NASA MSFC. This method employs a distribution of stress to allow the stress exponent to be determined from each test, rather than from the curve fit through measurements from multiple samples that is required by conventional methods. The sample is deformed by the centripetal acceleration from the rapid rotation, and the deformed shapes are analyzed to determine the strain. Based on a mathematical proof, which revealed that the stress exponent was determined uniquely by the ratio of the polar to equatorial strains, a series of finite-element analyses with the models of different stress exponents were also performed to determine the stress exponent corresponding to the measured strain ratio. The stress exponent from the ESL experiment showed a good agreement with those from the literature and the conventional creep test.

  3. Enhancement to Non-Contacting Stress Measurement of Blade Vibration Frequency

    Science.gov (United States)

    Platt, Michael; Jagodnik, John

    2011-01-01

    A system for turbo machinery blade vibration has been developed that combines time-of-arrival sensors for blade vibration amplitude measurement and radar sensors for vibration frequency and mode identification. The enabling technology for this continuous blade monitoring system is the radar sensor, which provides a continuous time series of blade displacement over a portion of a revolution. This allows the data reduction algorithms to directly calculate the blade vibration frequency and to correctly identify the active modes of vibration. The work in this project represents a significant enhancement in the mode identification and stress calculation accuracy in non-contacting stress measurement system (NSMS) technology when compared to time-of-arrival measurements alone.

  4. Non-contact ulcer area calculation system for neuropathic foot ulcer.

    Science.gov (United States)

    Shah, Parth; Mahajan, Siddaram; Nageswaran, Sharmila; Paul, Sathish Kumar; Ebenzer, Mannam

    2017-08-11

    Around 125,785 new cases in year 2013-14 of leprosy were detected in India as per WHO report on leprosy in September 2015 which accounts to approximately 62% of the total new cases. Anaesthetic foot caused by leprosy leads to uneven loading of foot leading to ulcer in approximately 20% of the cases. Much efforts have gone in identifying newer techniques to efficiently monitor the progress of ulcer healing. Current techniques followed in measuring the size of ulcers, have not been found to be so accurate but are still is followed by clinicians across the globe. Quantification of prognosis of the condition would be required to understand the efficacy of current treatment methods and plan for further treatment. This study aims at developing a non contact technique to precisely measure the size of ulcer in patients affected by leprosy. Using MATLAB software, GUI was designed to process the acquired ulcer image by segmenting and calculating the pixel area of the image. The image was further converted to a standard measurement using a reference object. The developed technique was tested on 16 ulcer images acquired from 10 leprosy patients with plantar ulcers. Statistical analysis was done using MedCalc analysis software to find the reliability of the system. The analysis showed a very high correlation coefficient (r=0.9882) between the ulcer area measurements done using traditional technique and the newly developed technique, The reliability of the newly developed technique was significant with a significance level of 99.9%. The designed non-contact ulcer area calculating system using MATLAB is found to be a reliable system in calculating the size of ulcers. The technique would help clinicians have a reliable tool to monitor the progress of ulcer healing and help modify the treatment protocol if needed. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  5. Thermal screening of facial skin arterial hot spots using non-contact infrared radiometry

    International Nuclear Information System (INIS)

    Williams, E M; Heusch, A I; McCarthy, P W

    2008-01-01

    Non-contact infrared thermometry of facial skin offers advantages over less accessible internal body sites, especially when considering mass screening for febrile infectious disease. The forehead offers an obvious site, but does not present an isothermic surface, as various small arteries passing close to the surface create 'hot-spots'. The aim of this study is to use non-contact infrared (IR) thermometry to determine the link between the temperature at specific facial skin sites and clinical body temperature. A sample of 169 asymptomatic adults (age range 18–54 years) was screened with IR thermometers (Braun Thermoscan proLT for auditory meatus (AM) temperature representing clinical body temperature, and a Raytek, Raynger MX for skin surface temperature). Peak IR skin temperature was measured over the course of each posterior auricular artery (PAA) and each superficial temporal artery (STA). In a sub-group (n = 54) the peak skin temperature of the forehead's metopic region (MR) was also recorded. There were no differences (P > 0.05) between the PAA and STA at 34.2 ± 0.9 °C and 34.2 ± 0.7 °C, respectively, which were 2.5 °C cooler than the AM temperature (36.7 ± 0.5 °C, p 2 = 0.63, p < 0.001) between PAA and STA. There were no asymmetric temperature differences between the left and right sides and males had warmer skin over the MR (F, 33.6 ± 0.7 °C versus M, 34.4 ± 0.6 °C, p < 0.001). Although a lack of correlation between either PAA or STA and AM was apparent in asymptomatics, further research in symptomatics is required to determine the usefulness of these measurements in mass screening of conditions such as fever

  6. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury.

    Science.gov (United States)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars L; Myklebust, Grethe; Kallemose, Thomas; Lauridsen, Hanne B; Hölmich, Per; Aagaard, Per; Zebis, Mette K

    2016-06-01

    Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. Sixty-two adolescent female elite football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored during three standardized screening tests - i.e. one-legged horizontal hop (OLH), drop vertical jump (DJ) and sidecutting (SC). Neuromuscular pre-activity was measured in the time interval 10ms prior to initial contact on a force plate. For neuromuscular hamstring muscle pre-activity, correlation analysis (Spearman correlation coefficient) showed low-to-moderate correlations between SC and 1) DJ (rs=0.34-0.36, Phamstring pre-activity share some common variance during the examined tests. However, a lack of strong correlation suggests that we cannot generalize one risk factor during one test to another test. The present data demonstrate that one-legged horizontal hop and drop vertical jump testing that are commonly used in the clinical setting does not resemble the specific neuromuscular activity patterns known to exist during sidecutting, a well known high risk movement for non-contact ACL injury. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Detection of subclinical keratoconus through non-contact tonometry and the use of discriminant biomechanical functions.

    Science.gov (United States)

    Peña-García, Pablo; Peris-Martínez, Cristina; Abbouda, Alessandro; Ruiz-Moreno, José M

    2016-02-08

    The purpose of the present study was to develop a discriminant function departing from the biomechanical parameters provided by a non-contact tonometer (Corvis-ST, Oculus Optikgeräte, Wetzlar, Germany) to distinguish subclinical keratoconus from normal eyes. 212 eyes (120 patients) were divided in two groups: 184 healthy eyes of 92 patients aged 32.99 ± 7.85 (21-73 years) and 28 eyes of 28 patients aged 37.79 ± 14.21 (17-75 years) with subclinical keratoconus. The main outcome measures were age, sex, intraocular pressure (IOP), corneal central thickness (CCT) and other specific biomechanical parameters provided by the tonometer. Correlations between all biomechanical parameters and the rest of variables were evaluated. The biomechanical measures were corrected in IOP and CCT (since these variable are not directly related with the corneal structure and biomechanical behavior) to warrant an accurate comparison between both types of eyes. Two discriminant functions were created from the set of corrected variables. The best discriminant function created depended on three parameters: maximum Deformation Amplitude (corrected in IOP and CCT), First Applanation time (corrected in CCT) and CCT. Statistically significant differences were found between groups for this function (p=2·10(-10); Mann-Withney test). The area under the Receiving Operating Characteristic was 0.893 ± 0.028 (95% confidence interval 0.838-0.949). Sensitivity and specificity were 85.7% and 82.07% respectively. These results show that the use of biomechanical parameters provided by non-contact tonometry, previous normalization, combined with the theory of discriminant functions is a useful tool for the detection of subclinical keratoconus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Non-contact and contact measurement system for detecting projectile position in electromagnetic launch bore

    Science.gov (United States)

    Xu, Weidong; Yuan, Weiqun; Xu, Rong; Zhao, Hui; Cheng, Wenping; Zhang, Dongdong; Zhao, Ying; Yan, Ping

    2017-12-01

    This paper introduces a new measurement system for measuring the position of a projectile within a rapid fire electromagnetic launching system. The measurement system contains both non-contact laser shading and metal fiber contact measurement devices. Two projectiles are placed in the rapid fire electromagnetic launch bore, one in the main accelerating segment and the other in the pre-loading segment. The projectile placed in the main accelerating segment should be shot first, and then the other is loaded into the main segment from the pre-loading segment. The main driving current (I-main) can only be discharged again when the second projectile has arrived at the key position (the projectile position corresponds to the discharging time) in the main accelerating segment. So, it is important to be able to detect when the second projectile arrives at the key position in the main accelerating segment. The B-dot probe is the most widely used system for detecting the position of the projectile in the electromagnetic launch bore. However, the B-dot signal is affected by the driving current amplitude and the projectile velocity. There is no current in the main accelerating segment when the second projectile moves into this segment in rapid fire mode, so the B-dot signal for detecting the key position is invalid. Due to the presence of a high-intensity magnetic field, a high current, a high-temperature aluminum attachment, smoke and strong vibrations, it is very difficult to detect the projectile position in the bore accurately. So, other measurements need to be researched and developed in order to achieve high reliability. A measurement system based on a laser (non-contact) and metal fibers (contact) has been designed, and the integrated output signal based on this detector is described in the following paper.

  9. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line.

    Science.gov (United States)

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-12-30

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

  10. DistancePPG: Robust non-contact vital signs monitoring using a camera

    Science.gov (United States)

    Kumar, Mayank; Veeraraghavan, Ashok; Sabharwal, Ashutosh

    2015-01-01

    Vital signs such as pulse rate and breathing rate are currently measured using contact probes. But, non-contact methods for measuring vital signs are desirable both in hospital settings (e.g. in NICU) and for ubiquitous in-situ health tracking (e.g. on mobile phone and computers with webcams). Recently, camera-based non-contact vital sign monitoring have been shown to be feasible. However, camera-based vital sign monitoring is challenging for people with darker skin tone, under low lighting conditions, and/or during movement of an individual in front of the camera. In this paper, we propose distancePPG, a new camera-based vital sign estimation algorithm which addresses these challenges. DistancePPG proposes a new method of combining skin-color change signals from different tracked regions of the face using a weighted average, where the weights depend on the blood perfusion and incident light intensity in the region, to improve the signal-to-noise ratio (SNR) of camera-based estimate. One of our key contributions is a new automatic method for determining the weights based only on the video recording of the subject. The gains in SNR of camera-based PPG estimated using distancePPG translate into reduction of the error in vital sign estimation, and thus expand the scope of camera-based vital sign monitoring to potentially challenging scenarios. Further, a dataset will be released, comprising of synchronized video recordings of face and pulse oximeter based ground truth recordings from the earlobe for people with different skin tones, under different lighting conditions and for various motion scenarios. PMID:26137365

  11. Control de velocidad del motor de indución empleando linealización por realimentación de estados Speed control of induction motor using state feedback linearization

    Directory of Open Access Journals (Sweden)

    Eduardo Giraldo Suárez

    2009-01-01

    Full Text Available Este documento presenta la aplicación de la técnica de control no lineal clásica llamada linealización por realimentación de variables de estado. Se hace una aplicación en el motor de inducción, la variable a controlar es la velocidad del eje del motor, el sistema emplea el esquema de control vectorial para máquinas de corriente alterna desarrollado en las últimas décadas; este método es análogo a la técnica de control del motor de corriente directa. El modelo del motor de inducción se describe en el sistema de coordenadas de campo orientado del flujo de rotor y se muestra una introducción al producto y la derivada de Lie, empleados en el diseño del controlador no lineal.This articles shows the application of a classic non-linear control technique called "linearization by feedback of status variables." An application on the induction engine is made. Variable to be controlled is speed of the engine shaft. The system employs a vectorial control scheme for AC engines developed during the last decades. This is a method analogous to the DC engine control technique. Induction engine model is described in the guided field coordinate system of rotor flow. Introduction to the product and Lie derivative used for designing the non-linear controller are shown.

  12. A surgical navigation system for non-contact diffuse optical tomography and intraoperative cone-beam CT

    Science.gov (United States)

    Daly, Michael J.; Muhanna, Nidal; Chan, Harley; Wilson, Brian C.; Irish, Jonathan C.; Jaffray, David A.

    2014-02-01

    A freehand, non-contact diffuse optical tomography (DOT) system has been developed for multimodal imaging with intraoperative cone-beam CT (CBCT) during minimally-invasive cancer surgery. The DOT system is configured for near-infrared fluorescence imaging with indocyanine green (ICG) using a collimated 780 nm laser diode and a nearinfrared CCD camera (PCO Pixelfly USB). Depending on the intended surgical application, the camera is coupled to either a rigid 10 mm diameter endoscope (Karl Storz) or a 25 mm focal length lens (Edmund Optics). A prototype flatpanel CBCT C-Arm (Siemens Healthcare) acquires low-dose 3D images with sub-mm spatial resolution. A 3D mesh is extracted from CBCT for finite-element DOT implementation in NIRFAST (Dartmouth College), with the capability for soft/hard imaging priors (e.g., segmented lymph nodes). A stereoscopic optical camera (NDI Polaris) provides real-time 6D localization of reflective spheres mounted to the laser and camera. Camera calibration combined with tracking data is used to estimate intrinsic (focal length, principal point, non-linear distortion) and extrinsic (translation, rotation) lens parameters. Source/detector boundary data is computed from the tracked laser/camera positions using radiometry models. Target registration errors (TRE) between real and projected boundary points are ~1-2 mm for typical acquisition geometries. Pre-clinical studies using tissue phantoms are presented to characterize 3D imaging performance. This translational research system is under investigation for clinical applications in head-and-neck surgery including oral cavity tumour resection, lymph node mapping, and free-flap perforator assessment.

  13. Measurement of intraocular pressure using the NT-4000: a new non-contact tonometer equipped with pulse synchronous measurement function.

    Science.gov (United States)

    Yaoeda, Kiyoshi; Shirakashi, Motohiro; Fukushima, Atsushi; Funaki, Shigeo; Funaki, Haruko; Ofuchi, Nobutaka; Nakatsue, Tomoko; Abe, Haruki

    2005-06-01

    NT-4000 (Nidek Co. Ltd., Gamagori, Japan) is a new non-contact tonometer (NCT) equipped with pulse synchronous measurement function that can measure intraocular pressure (IOP) synchronized with the ocular pulse. The purpose of this study was to evaluate the usefulness of NT-4000 in normal subjects and in patients with glaucoma and ocular hypertension. This study included 175 eyes of 175 subjects. Firstly, the IOP was measured using NT-4000 without the pulse synchronous measurement function (NTn). Secondly, the IOP at peak, middle, and trough phases of the pulse signal were measured using NT-4000 with the pulse synchronous measurement function (NTp, NTm, NTt, respectively). Additionally, the IOP was measured with Goldmann applanation tonometer (GT). The coefficient of variation (CV) of three readings in the NCT measurements was used to evaluate the intra-session reproducibility. Statistical comparisons were performed using Wilcoxon signed rank test and one-way analysis of variance with Scheffe's test. Linear regression analysis was used to calculate correlation coefficients. P values less than 0.05 were accepted as statistically significant. The CV of NTn, NTp, NTm, and NTt were 6.4%, 5.5%, 4.9%, and 5.2%, respectively. The CV of NTp, NTm, and NTt were significantly smaller than that of NTn (P = 0.007, P < 0.001, P < 0.001, respectively). NTp was significantly higher than NTt (P = 0.038). GT was significantly correlated with NTn, NTp, NTm, and NTt (r = 0.898, P < 0.001; r = 0.912, P < 0.001; r = 0.908, P < 0.001; r = 0.900, P < 0.001, respectively). NT-4000 can detect the fluctuation of IOP associated with the ocular pulse.

  14. Reliability of the non-contact tono-pachymeter Tonopachy NT-530P in healthy eyes.

    Science.gov (United States)

    García-Resúa, Carlos; Pena-Verdeal, Hugo; Miñones, Mercedes; Giraldez, M Jesus; Yebra-Pimentel, Eva

    2013-05-01

    Non-contact Tonopachy NT-530P (Nidek Co., LTD) provides intraocular pressure (IOP) and central corneal thickness (CCT) measurements. This study assesses the reliability and repeatability of its IOP measurements in young healthy adult subjects. IOP was determined in the right eye of 64 healthy patients using Tonopachy followed by the Canon TX-10 non-contact and Goldmann applanation (GAT) tonometers. Tonopachy IOP measurements were corrected (Tonopachy-C) or not (Tonopachy-NC) by the instrument for central corneal thickness. Central corneal thickness measurements provided by Tonopachy were also used to correlate (Pearson's coefficient) central corneal thickness with the GAT and Canon TX-10 IOPs. Repeatability of Tonopachy and GAT was assessed in the right eye of 31 subjects in two separate sessions one week apart. Differences between pairs of instruments and between sessions were determined using Bland-Altman plots. The coefficient of repeatability was calculated as the 95% limits of agreement (LoA) of differences between the two sessions. Tonopachy-NC, Tonopachy-C, Canon TX-10 and the Goldmann tonometers showed a mean IOP of 14.62, 15.64, 15.02 and 14.68 mmHg, respectively. Tonopachy-NC and Canon TX-10 readings did not differ significantly from the Goldmann (p > 0.05), with close agreement with both tonometers (GAT versus Tonopachy-NC: -3.84 to 3.96 mmHg; Goldmann versus Canon TX-10: -4.75 to 4.07 mmHg). Tonopachy-C readings differed significantly from Goldmann (mean difference -0.96 mmHg, p = 0.001, LoA from -5.09 to 3.17). Coefficients of repeatability were ± 3.70, ± 3.14 and ± 3.33 mmHg for GAT, Tonopachy-NC and Tonopachy-C, respectively. Central corneal thickness measured with Tonopachy was 530.42 ± 34.96 μm. There was a significant correlation between central corneal thickness and IOP for all tonometers except Tonopachy-C. Reasonable agreement was observed between the Goldmann and Tonopachy. This instrument provides reliable and repeatable IOP

  15. Non-Contact Thermal Properties Measurement with Low-Power Laser and IR Camera System

    Science.gov (United States)

    Hudson, Troy L.; Hecht, Michael H.

    2011-01-01

    As shown by the Phoenix Mars Lander's Thermal and Electrical Conductivity Probe (TECP), contact measurements of thermal conductivity and diffusivity (using a modified flux-plate or line-source heat-pulse method) are constrained by a number of factors. Robotic resources must be used to place the probe, making them unavailable for other operations for the duration of the measurement. The range of placement is also limited by mobility, particularly in the case of a lander. Placement is also subject to irregularities in contact quality, resulting in non-repeatable heat transfer to the material under test. Most important from a scientific perspective, the varieties of materials which can be measured are limited to unconsolidated or weakly-cohesive regolith materials, rocks, and ices being too hard for nominal insertion strengths. Accurately measuring thermal properties in the laboratory requires significant experimental finesse, involving sample preparation, controlled and repeatable procedures, and, practically, instrumentation much more voluminous than the sample being tested (heater plates, insulation, temperature sensors). Remote measurements (infrared images from orbiting spacecraft) can reveal composite properties like thermal inertia, but suffer both from a large footprint (low spatial resolution) and convolution of the thermal properties of a potentially layered medium. In situ measurement techniques (the Phoenix TECP is the only robotic measurement of thermal properties to date) suffer from problems of placement range, placement quality, occupation of robotic resources, and the ability to only measure materials of low mechanical strength. A spacecraft needs the ability to perform a non-contact thermal properties measurement in situ. Essential components include low power consumption, leveraging of existing or highly-developed flight technologies, and mechanical simplicity. This new in situ method, by virtue of its being non-contact, bypasses all of these

  16. The numerical assessment of motion strategies for integrated linear motor during starting of a free-piston engine generator

    Science.gov (United States)

    Razali Hanipah, M.; Razul Razali, Akhtar

    2017-10-01

    Free-piston engine generator (FPEG) provides a novel method for electrical power generation in hybrid electric vehicle applications with scarcely reported prototype development and testing. This paper is looking into the motion control strategy for motoring the FPEG during starting. There are two motion profiles investigated namely, trapezoidal velocity and Scurve velocity. Both motion profiles were investigated numerically and the results have shown that the S-curve motion can only achieve 80% of the stroke when operated at the proposed motoring speed of 10Hz.

  17. Imaging contrast and tip-sample interaction of non-contact amplitude modulation atomic force microscopy with Q -control

    International Nuclear Information System (INIS)

    Shi, Shuai; Guo, Dan; Luo, Jianbin

    2017-01-01

    Active quality factor ( Q ) exhibits many promising properties in dynamic atomic force microscopy. Energy dissipation and image contrasts are investigated in the non-contact amplitude modulation atomic force microscopy (AM-AFM) with an active Q -control circuit in the ambient air environment. Dissipated power and virial were calculated to compare the highly nonlinear interaction of tip-sample and image contrasts with different Q gain values. Greater free amplitudes and lower effective Q values show better contrasts for the same setpoint ratio. Active quality factor also can be employed to change tip-sample interaction force in non-contact regime. It is meaningful that non-destructive and better contrast images can be realized in non-contact AM-AFM by applying an active Q -control to the dynamic system. (paper)

  18. Comparison of intraocular pressure measurement between rebound, non-contact and Goldmann applanation tonometry in treated glaucoma patients.

    Science.gov (United States)

    Vincent, Stephen J; Vincent, Roslyn A; Shields, David; Lee, Graham A

    2012-01-01

    To compare the intraocular pressure readings obtained with the iCare rebound tonometer and the 7CR non-contact tonometer with those measured by Goldmann applanation tonometry in treated glaucoma patients. A prospective, cross-sectional study was conducted in a private tertiary glaucoma clinic. One hundred nine (54 males : 55 females) patients including only eyes under medical treatment for glaucoma. Measurement by Goldmann applanation tonometry, iCare rebound tonometry and 7CR non-contact tonometry. Intraocular pressure. There were strong correlations between the intraocular pressure measurements obtained with Goldmann and both the rebound and non-contact tonometers (Spearman r-values ≥ 0.79, P tonometer. For the rebound tonometer, the mean intraocular pressure was slightly higher compared with the Goldmann applanation tonometer in the right eyes (P = 0.02), and similar in the left eyes (P = 0.93); however, these differences did not reach statistical significance. The Goldmann correlated measurements from the non-contact tonometer were lower than the average Goldmann reading for both right (P 0.01) eyes. The corneal compensated measurements from the non-contact tonometer were significantly higher compared with the other tonometers (P ≤ 0.001). The iCare rebound tonometer and the 7CR non-contact tonometer measure intraocular pressure in fundamentally different ways to the Goldmann applanation tonometer. The resulting intraocular pressure values vary between the instruments and will need to be considered when comparing clinical versus home acquired measurements. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

  19. Balancing Vibrations at Harmonic Frequencies by Injecting Harmonic Balancing Signals into the Armature of a Linear Motor/Alternator Coupled to a Stirling Machine

    Science.gov (United States)

    Holliday, Ezekiel S. (Inventor)

    2014-01-01

    Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic.

  20. Incidence of open-angle glaucoma and screening of the intraocular pressure with a non-contact tonometer.

    Science.gov (United States)

    Rouhiainen, H; Teräsvirta, M

    1990-06-01

    New equipment for measuring intraocular pressure have been introduced lately. One of these is the Keeler Pulsair non-contact tonometer which uses pressurized air in measurement. It is found to be safe and easy to use in practice, but it seems to give 1.5-2.0 mmHg lower reading than the Goldmann applanation tonometer. This was confirmed by the present study, where non-contact tonometry was controlled by applanation tonometry with a 2-3 week delay between the measurements. However, for screening procedures the accuracy of the apparatus can be considered as sufficient.

  1. Dynamic torsional response analysis of mechanoluminescent paint and its application to non-contacting automotive torque transducers

    International Nuclear Information System (INIS)

    Kim, Gi-Woo; Kim, Ji-Sik

    2014-01-01

    This paper presents the result of a preliminary experimental study on the dynamic torsional response analysis of mechanoluminescent (ML) paint for potential development as a new type of non-contacting torque transducer. The torsional torque applied to a transmission shaft is measured by sensing the ML intensity emitting from an ML paint coating a transmission shaft. This study provides the fundamental knowledge for the development of new non-contacting torque sensing technology based on the ML intensity detection. The proposed measurement principle appears to offer potential applications in automotive torque measurement systems, even though the loading rate-dependent characteristics of the ML intensity needs to be examined further. (paper)

  2. Dynamic torsional response analysis of mechanoluminescent paint and its application to non-contacting automotive torque transducers

    Science.gov (United States)

    Kim, Gi-Woo; Kim, Ji-Sik

    2014-01-01

    This paper presents the result of a preliminary experimental study on the dynamic torsional response analysis of mechanoluminescent (ML) paint for potential development as a new type of non-contacting torque transducer. The torsional torque applied to a transmission shaft is measured by sensing the ML intensity emitting from an ML paint coating a transmission shaft. This study provides the fundamental knowledge for the development of new non-contacting torque sensing technology based on the ML intensity detection. The proposed measurement principle appears to offer potential applications in automotive torque measurement systems, even though the loading rate-dependent characteristics of the ML intensity needs to be examined further.

  3. Non-contact adhesion to self-affine surfaces: A theoretical model

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A., E-mail: makeev@umich.edu

    2013-11-22

    Strength of adhesion between materials is known to be strongly influenced by interface irregularities. In this work, I devise a perturbative approach to describe the effect of self-affine roughness on non-contact adhesive interactions. The hierarchy of the obtained analytical solutions is the following. First, analytical formulae are deduced to describe roughness corrections to the van der Waals interaction energies between a hemi-space adherend, bounded by a self-affine surface, and a point-like adherent. Second, the problem of two hemi-spaces, one of which has a planar surface, and the other is bounded by a self-affine surface, is solved analytically. In the latter case, a numerical analysis is performed to delineate the behavior of the roughness corrections as a function of the parameters, characterizing self-affine fractal surface roughness. The problem of two hemi-spaces, both bounded by self-affine fractal surfaces, is also addressed in this work. The model's predictions are compared with previously reported theoretical results and available experimental data.

  4. A non-contact high resolution piezoelectric film based sensor for monitoring breathing during sleep

    Science.gov (United States)

    Johnston, Robert; Nakano, Katsuya; Fujita, Kento; Misaki, Shinya; Fujii, Hiroyuki; Misaki, Yukinori

    2017-07-01

    Currently, research for measuring human breathing during sleep is actively being conducted into using technologies that include piezoelectric, ultrasonic, microwave and infrared rays. But various problems have led to not many practical applications. As such, it was decided to develop a PVDF (PolyVinylidene DiFluoride) based non-contact high resolution sensor for monitoring a subject's breathing as they sleep. Development of the high resolution respiration sensor was possible through the use of PVDF piezoelectric film and the development of a new sensor configuration. Although there was already an existing respiration sensor research resulting product available, is weak signal strength made it very sensitive to noise and difficult to measure respiration accurately. As such, complicated circuits and signal processing were needed. A new high resolution breathing sensor was developed with greater signal strength and with just the use of some simple circuits and signal processing, was able to accurately measure subject breathing. Also due to the greater signal strength, it became possible to measure both heart rate and respiration rate simultaneously.

  5. Non-contact method of search and analysis of pulsating vessels

    Science.gov (United States)

    Avtomonov, Yuri N.; Tsoy, Maria O.; Postnov, Dmitry E.

    2018-04-01

    Despite the variety of existing methods of recording the human pulse and a solid history of their development, there is still considerable interest in this topic. The development of new non-contact methods, based on advanced image processing, caused a new wave of interest in this issue. We present a simple but quite effective method for analyzing the mechanical pulsations of blood vessels lying close to the surface of the skin. Our technique is a modification of imaging (or remote) photoplethysmography (i-PPG). We supplemented this method with the addition of a laser light source, which made it possible to use other methods of searching for the proposed pulsation zone. During the testing of the method, several series of experiments were carried out with both artificial oscillating objects as well as with the target signal source (human wrist). The obtained results show that our method allows correct interpretation of complex data. To summarize, we proposed and tested an alternative method for the search and analysis of pulsating vessels.

  6. Modelling atomic scale manipulation with the non-contact atomic force microscope

    International Nuclear Information System (INIS)

    Trevethan, T; Watkins, M; Kantorovich, L N; Shluger, A L; Polesel-Maris, J; Gauthier, S

    2006-01-01

    We present the results of calculations performed to model the process of lateral manipulation of an oxygen vacancy in the MgO(001) surface using the non-contact atomic force microscope (NC-AFM). The potential energy surfaces for the manipulation as a function of tip position are determined from atomistic modelling of the MgO(001) surface interacting with a Mg terminated MgO tip. These energies are then used to model the dynamical evolution of the system as the tip oscillates and at a finite temperature using a kinetic Monte Carlo method. The manipulation process is strongly dependent on the lateral position of the tip and the system temperature. It is also found that the expectation value of the point at which the vacancy jumps depends on the trajectory of the oscillating cantilever as the surface is approached. The effect of the manipulation on the operation of the NC-AFM is modelled with a virtual dynamic AFM, which explicitly simulates the entire experimental instrumentation and control loops. We show how measurable experimental signals can result from a single controlled atomic scale event and suggest the most favourable conditions for achieving successful atomic scale manipulation experimentally

  7. Quantitative analysis of tip-sample interaction in non-contact scanning force spectroscopy

    International Nuclear Information System (INIS)

    Palacios-Lidon, Elisa; Colchero, Jaime

    2006-01-01

    Quantitative characterization of tip-sample interaction in scanning force microscopy is fundamental for optimum image acquisition as well as data interpretation. In this work we discuss how to characterize the electrostatic and van der Waals contribution to tip-sample interaction in non-contact scanning force microscopy precisely. The spectroscopic technique presented is based on the simultaneous measurement of cantilever deflection, oscillation amplitude and frequency shift as a function of tip-sample voltage and tip-sample distance as well as on advanced data processing. Data are acquired at a fixed lateral position as interaction images, with the bias voltage as fast scan, and tip-sample distance as slow scan. Due to the quadratic dependence of the electrostatic interaction with tip-sample voltage the van der Waals force can be separated from the electrostatic force. Using appropriate data processing, the van der Waals interaction, the capacitance and the contact potential can be determined as a function of tip-sample distance. The measurement of resonance frequency shift yields very high signal to noise ratio and the absolute calibration of the measured quantities, while the acquisition of cantilever deflection allows the determination of the tip-sample distance

  8. [Comparative study between the non-contact pneumotonometer Canon TX10 and the Goldmann tonometer].

    Science.gov (United States)

    Sánchez-Tocino, H; Bringas-Calvo, R; Iglesias-Cortiñas, D

    2005-11-01

    To study and contrast the measurement of intraocular pressure (IOP) with an air non-contact tonometer (Canon TX-10) with that obtained with the Goldmann tonometer. Intraocular pressure was measured in 649 subjects with both the pneumotonometer and the Goldmann tonometer. Statistically significant differences between the results obtained by both tonometers and the influence of variables including age, corneal thickness, and corneal curvature were studied. The mean age of the study population was 48.5 years, standard deviation (SD) 7.6 years, with a range of 22-68 years. The mean IOP was 15.4, SD 2.7 mm Hg, (range 8-25) with the Goldmann tonometer and 15.6, SD 2.9 mm Hg (range 8-29) with the pneumotonometer. There was a statistically significant difference between the measurements using the air pneumotonometer and the Goldmann tonometer (ptonometers was 0.24, SD 2 mm Hg. Seventy-five percent of measurements were in the range of +/-1, 85% in +/-2, and 95% in the Bland and Altman's interval of 4.42, -3.94. These differences were more significant for higher values of IOP, in thicker corneas and in corneas with greater curvature. A correlation between IOP and age was not found (p=0.247). The pneumotonometer is a useful and reliable instrument for measuring the IOP providing there is additional checking in cases with borderline values of IOP, or excessive corneal thickness and/or curvature.

  9. CORRELATION OF INTRAOCULAR PRESSURE MEASUREMENTS WITH NON CONTACT TONOMETER AND GOLDMANN APPLANATION TONOMETRY

    Directory of Open Access Journals (Sweden)

    Leya Sara George

    2017-07-01

    Full Text Available BACKGROUND A complete ophthalmologic examination includes intraocular pressure (IOP measurement, which is a routine procedure and is important for diagnosis and monitoring of glaucoma. IOP measurement is most commonly done using Goldmann Applanation tonometer and Non-Contact tonometer. MATERIALS AND METHODS In this study IOP measurements of 500 eyes (glaucomatous and non-glaucomatous were performed using GAT and NCT on patients visiting the outpatient clinic of Department of Ophthalmology at Christian Medical College and Hospital, Ludhiana. This was a cross sectional and observational study. Comparison of IOP values was done in different IOP ranges. CCT was measured and analysis of its correlation with GAT and NCT was done. RESULTS Both methods of tonometry correlated significantly in patients with IOP <24 mm Hg. The mean IOP measured by NCT, was 16.06 ± 5.85 mm Hg and the mean IOP measurement by GAT was 16.61 ± 6.94 mm Hg. Intraocular pressure readings with GAT and NCT positively correlated with CCT. CONCLUSION NCT may be useful for screening in clinical settings but borderline high IOP readings should be confirmed with GAT. Our findings, also suggest that CCT is an essential variable to consider in interpreting IOP readings.

  10. Comparison of a new non-contact tonometer with Goldmann applanation.

    Science.gov (United States)

    Moseley, M J; Evans, N M; Fielder, A R

    1989-01-01

    A comparison of a new non-contact tonometer (Keeler Pulsair: Keeler UK Ltd) with the Goldmann applanation tonometer is reported. Measurements of intraocular pressure were obtained from 182 eyes of 94 patients. At low pressures (less than 10 mmHg) the candidate tonometer tended to overestimate pressures obtained with the Goldmann tonometer whilst at high pressures (greater than 19 mmHg) those obtained by Goldmann applanation were underestimated. Between 10 and 19 mmHg there was no significant difference between readings obtained with either method. Up to 71% of averaged Pulsair measurements fell within +/- 3 mmHg of those obtained with the Goldmann tonometer increasing to 78% if pressures greater than or equal to 30 mmHg obtained with the Pulsair tonometer were excluded. Adopting a screening criterion of greater than or equal to 21 mmHg (Goldmann) resulted in a sensitivity of 85% and a specificity of 95%. Some evidence that serial Pulsair readings are influenced by the ocular pulse is presented. It is concluded that the Pulsair tonometer can provide clinically useful measurements of intraocular pressure.

  11. Non-Contact Surface Roughness Measurement by Implementation of a Spatial Light Modulator

    Directory of Open Access Journals (Sweden)

    Laura Aulbach

    2017-03-01

    Full Text Available The surface structure, especially the roughness, has a significant influence on numerous parameters, such as friction and wear, and therefore estimates the quality of technical systems. In the last decades, a broad variety of surface roughness measurement methods were developed. A destructive measurement procedure or the lack of feasibility of online monitoring are the crucial drawbacks of most of these methods. This article proposes a new non-contact method for measuring the surface roughness that is straightforward to implement and easy to extend to online monitoring processes. The key element is a liquid-crystal-based spatial light modulator, integrated in an interferometric setup. By varying the imprinted phase of the modulator, a correlation between the imprinted phase and the fringe visibility of an interferogram is measured, and the surface roughness can be derived. This paper presents the theoretical approach of the method and first simulation and experimental results for a set of surface roughnesses. The experimental results are compared with values obtained by an atomic force microscope and a stylus profiler.

  12. Air microjet system for non-contact force application and the actuation of micro-structures

    International Nuclear Information System (INIS)

    Khare, S M; Venkataraman, V

    2016-01-01

    We demonstrate a non-contact technique to apply calibrated and localized forces in the micro-Newton to milli-Newton range using an air microjet. An electromagnetically actuated diaphragm controlled by a signal generator is used to generate the air microjet. With a nozzle diameter of 150 μm, the microjet diameter was maintained to a maximum of 1 mm at a distance of 5 mm from the nozzle. The force generated by the microjet was measured using a commercial force sensor to determine the velocity profile of the jet. Axial flow velocities of up to 25 m s −1 were obtained at distances as long as 6 mm. The microjet exerted a force up to 1 μN on a poly dimethyl siloxane (PDMS) micropillar (50 μm in diameter, 157 μm in height) and 415 μN on a PDMS membrane (3 mm in diameter, 28 μm thick). We also demonstrate that from a distance of 6 mm our microjet can exert a peak pressure of 187 Pa with a total force of about 84 μN on a flat surface with 8 V operating voltage. Out of the cleanroom fabrication and robust design make this system cost effective and durable. (technical note)

  13. Air microjet system for non-contact force application and the actuation of micro-structures

    Science.gov (United States)

    Khare, S. M.; Venkataraman, V.

    2016-01-01

    We demonstrate a non-contact technique to apply calibrated and localized forces in the micro-Newton to milli-Newton range using an air microjet. An electromagnetically actuated diaphragm controlled by a signal generator is used to generate the air microjet. With a nozzle diameter of 150 μm, the microjet diameter was maintained to a maximum of 1 mm at a distance of 5 mm from the nozzle. The force generated by the microjet was measured using a commercial force sensor to determine the velocity profile of the jet. Axial flow velocities of up to 25 m s-1 were obtained at distances as long as 6 mm. The microjet exerted a force up to 1 μN on a poly dimethyl siloxane (PDMS) micropillar (50 μm in diameter, 157 μm in height) and 415 μN on a PDMS membrane (3 mm in diameter, 28 μm thick). We also demonstrate that from a distance of 6 mm our microjet can exert a peak pressure of 187 Pa with a total force of about 84 μN on a flat surface with 8 V operating voltage. Out of the cleanroom fabrication and robust design make this system cost effective and durable.

  14. Radiation thermometry - non-contact temperature measurements; Strahlungsthermometrie - Temperaturen beruehrungslos messen

    Energy Technology Data Exchange (ETDEWEB)

    Hollandt, J. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Fachbereich Hochtemperatur- und Vakuumphysik; Hartmann, J. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe Hochtemperaturskala; Gutschwager, B. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe Infrarot-Strahlungsthermometrie; Struss, O. [HEITRONICS Infrarot Messtechnik GmbH (Germany)

    2007-09-15

    The temperature is one of the measurands most frequently determined, as it decisively influences physical, chemical and biological processes. To be able to evaluate, optimize, repeat and compare industrial procedures, temperatures must be measured with sufficient accuracy and worldwide uniformity. This is done with the aid of the regulations and instructions of the international temperature scale. Today, non-contact measurements of surface temperatures can be performed without problems with radiation thermometers over a temperature range from -100 C up to 3000 C. Compared to contacting measurements, radiation-thermometric temperature measurement offers a series of advantages. Radiation thermometers react very fast and the measurement is not influenced by heat supply or dissipation. This allows objects to be measured which move very fast, are energized or may experience fast temperature changes. Consequently, radiation thermometry is increasingly used for the monitoring and control of thermal processes, for maintenance and in building services engineering. The present contribution shall inform of the fundamentals of radiation-thermometric temperature measurement as well as of the construction and popular types of radiation thermometers. It will be explained how exact and worldwide uniform temperature measurement is guaranteed via the international temperature scale and the calibration of radiation thermometers. The emissivity of surfaces which is important in practical temperature measurements and some examples of industrial applications of radiation thermometers will be described. (orig.)

  15. Radiation thermometry - non-contact temperature measurements; Strahlungsthermometrie - Temperaturen beruehrungslos messen

    Energy Technology Data Exchange (ETDEWEB)

    Hollandt, J.; Hartmann, J.; Gutschwager, B. [Physikalisch-Technische Bundesanstalt, Berlin (Germany); Struss, O. [HEITRONICS Infrarot Messtechnik GmbH, Wiesbaden (Germany)

    2006-07-01

    The temperature is one of the measurands most frequently determined, as it decisively influences physical, chemical and biological processes. To be able to evaluate, optimize, repeat and compare industrial procedures, temperatures must be measured with sufficient accuracy and worldwide uniformity. This is done with the aid of the regulations and instructions of the international temperature scale. Today, non-contact measurements of surface temperatures can be performed without problems with radiation thermometers over a temperature range from -100 C up to 3000 C. Compared to contacting measurements, radiation-thermometric temperature measurement offers a series of advantages. Radiation thermometers react very fast and the measurement is not influenced by heat supply or dissipation. This allows objects to be measured which move very fast, are energized or may experience fast temperature changes. Consequently, radiation thermometry is increasingly used for the monitoring and control of thermal processes, for maintenance and in building services engineering. The present contribution shall inform of the fundamentals of radiation-thermometric temperature measurement as well as of the construction and popular types of radiation thermometers. It will be explained how exact and worldwide uniform temperature measurement is guaranteed via the international temperature scale and the calibration of radiation thermometers. The emissivity of surfaces which is important in practical temperature measurements and some examples of industrial applications of radiation thermometers will be described. (orig.)

  16. A portable non-contact displacement sensor and its application of lens centration error measurement

    Science.gov (United States)

    Yu, Zong-Ru; Peng, Wei-Jei; Wang, Jung-Hsing; Chen, Po-Jui; Chen, Hua-Lin; Lin, Yi-Hao; Chen, Chun-Cheng; Hsu, Wei-Yao; Chen, Fong-Zhi

    2018-02-01

    We present a portable non-contact displacement sensor (NCDS) based on astigmatic method for micron displacement measurement. The NCDS are composed of a collimated laser, a polarized beam splitter, a 1/4 wave plate, an aspheric objective lens, an astigmatic lens and a four-quadrant photodiode. A visible laser source is adopted for easier alignment and usage. The dimension of the sensor is limited to 115 mm x 36 mm x 56 mm, and a control box is used for dealing with signal and power control between the sensor and computer. The NCDS performs micron-accuracy with +/-30 μm working range and the working distance is constrained in few millimeters. We also demonstrate the application of the NCDS for lens centration error measurement, which is similar to the total indicator runout (TIR) or edge thickness difference (ETD) of a lens measurement using contact dial indicator. This application has advantage for measuring lens made in soft materials that would be starched by using contact dial indicator.

  17. Automatic detection of measurement points for non-contact vibrometer-based diagnosis of cardiac arrhythmias

    Science.gov (United States)

    Metzler, Jürgen; Kroschel, Kristian; Willersinn, Dieter

    2017-03-01

    Monitoring of the heart rhythm is the cornerstone of the diagnosis of cardiac arrhythmias. It is done by means of electrocardiography which relies on electrodes attached to the skin of the patient. We present a new system approach based on the so-called vibrocardiogram that allows an automatic non-contact registration of the heart rhythm. Because of the contactless principle, the technique offers potential application advantages in medical fields like emergency medicine (burn patient) or premature baby care where adhesive electrodes are not easily applicable. A laser-based, mobile, contactless vibrometer for on-site diagnostics that works with the principle of laser Doppler vibrometry allows the acquisition of vital functions in form of a vibrocardiogram. Preliminary clinical studies at the Klinikum Karlsruhe have shown that the region around the carotid artery and the chest region are appropriate therefore. However, the challenge is to find a suitable measurement point in these parts of the body that differs from person to person due to e. g. physiological properties of the skin. Therefore, we propose a new Microsoft Kinect-based approach. When a suitable measurement area on the appropriate parts of the body are detected by processing the Kinect data, the vibrometer is automatically aligned on an initial location within this area. Then, vibrocardiograms on different locations within this area are successively acquired until a sufficient measuring quality is achieved. This optimal location is found by exploiting the autocorrelation function.

  18. The Parkinsonian Subthalamic Network: Measures of Power, Linear, and Non-linear Synchronization and their Relationship to L-DOPA Treatment and OFF State Motor Severity.

    Science.gov (United States)

    West, Timothy; Farmer, Simon; Berthouze, Luc; Jha, Ashwani; Beudel, Martijn; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Brown, Peter; Litvak, Vladimir

    2016-01-01

    In this paper we investigated the dopaminergic modulation of neuronal interactions occurring in the subthalamic nucleus (STN) during Parkinson's disease (PD). We utilized linear measures of local and long range synchrony such as power and coherence, as well as Detrended Fluctuation Analysis for Phase Synchrony (DFA-PS)- a recently developed non-linear method that computes the extent of long tailed autocorrelations present in the phase interactions between two coupled signals. Through analysis of local field potentials (LFPs) taken from the STN we seek to determine changes in the neurodynamics that may underpin the pathophysiology of PD in a group of 12 patients who had undergone surgery for deep brain stimulation. We demonstrate up modulation of alpha-theta (5-12 Hz) band power in response to L-DOPA treatment, whilst low beta band power (15-20 Hz) band-power is suppressed. We also find evidence for significant local connectivity within the region surrounding STN although there was evidence for its modulation via administration of L-DOPA. Further to this we present evidence for a positive correlation between the phase ordering of bilateral STN interactions and the severity of bradykinetic and rigidity symptoms in PD. Although, the ability of non-linear measures to predict clinical state did not exceed standard measures such as beta power, these measures may help identify the connections which play a role in pathological dynamics.

  19. Non-linear Relationship between BOLD Activation and Amplitude of Beta Oscillations in the Supplementary Motor Area during Rhythmic Finger Tapping and Internal Timing

    Science.gov (United States)

    Gompf, Florian; Pflug, Anja; Laufs, Helmut; Kell, Christian A.

    2017-01-01

    Functional imaging studies using BOLD contrasts have consistently reported activation of the supplementary motor area (SMA) both during motor and internal timing tasks. Opposing findings, however, have been shown for the modulation of beta oscillations in the SMA. While movement suppresses beta oscillations in the SMA, motor and non-motor tasks that rely on internal timing increase the amplitude of beta oscillations in the SMA. These independent observations suggest that the relationship between beta oscillations and BOLD activation is more complex than previously thought. Here we set out to investigate this rapport by examining beta oscillations in the SMA during movement with varying degrees of internal timing demands. In a simultaneous EEG-fMRI experiment, 20 healthy right-handed subjects performed an auditory-paced finger-tapping task. Internal timing was operationalized by including conditions with taps on every fourth auditory beat, which necessitates generation of a slow internal rhythm, while tapping to every auditory beat reflected simple auditory-motor synchronization. In the SMA, BOLD activity increased and power in both the low and the high beta band decreased expectedly during each condition compared to baseline. Internal timing was associated with a reduced desynchronization of low beta oscillations compared to conditions without internal timing demands. In parallel with this relative beta power increase, internal timing activated the SMA more strongly in terms of BOLD. This documents a task-dependent non-linear relationship between BOLD and beta-oscillations in the SMA. We discuss different roles of beta synchronization and desynchronization in active processing within the same cortical region. PMID:29249950

  20. Non-linear Relationship between BOLD Activation and Amplitude of Beta Oscillations in the Supplementary Motor Area during Rhythmic Finger Tapping and Internal Timing.

    Science.gov (United States)

    Gompf, Florian; Pflug, Anja; Laufs, Helmut; Kell, Christian A

    2017-01-01

    Functional imaging studies using BOLD contrasts have consistently reported activation of the supplementary motor area (SMA) both during motor and internal timing tasks. Opposing findings, however, have been shown for the modulation of beta oscillations in the SMA. While movement suppresses beta oscillations in the SMA, motor and non-motor tasks that rely on internal timing increase the amplitude of beta oscillations in the SMA. These independent observations suggest that the relationship between beta oscillations and BOLD activation is more complex than previously thought. Here we set out to investigate this rapport by examining beta oscillations in the SMA during movement with varying degrees of internal timing demands. In a simultaneous EEG-fMRI experiment, 20 healthy right-handed subjects performed an auditory-paced finger-tapping task. Internal timing was operationalized by including conditions with taps on every fourth auditory beat, which necessitates generation of a slow internal rhythm, while tapping to every auditory beat reflected simple auditory-motor synchronization. In the SMA, BOLD activity increased and power in both the low and the high beta band decreased expectedly during each condition compared to baseline. Internal timing was associated with a reduced desynchronization of low beta oscillations compared to conditions without internal timing demands. In parallel with this relative beta power increase, internal timing activated the SMA more strongly in terms of BOLD. This documents a task-dependent non-linear relationship between BOLD and beta-oscillations in the SMA. We discuss different roles of beta synchronization and desynchronization in active processing within the same cortical region.

  1. FY 2000 report on the results of the technology development of energy use reduced machine tools, etc. Development of the linear motor system for realization of energy conservation and commercialization; 2000 nendo energy shiyo gorika kosaku kiki nado gijutsu kaihatsu seika hokokusho. Shoeneka to jitsuyoka wo jitsugensuru linear motor system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In relation to the drive system of machine tools widely used as production facilities for automobiles, home electric appliances, etc., the R and D were made of a high efficiency linear motor system of which attention was paid to energy rationalization and environmental loads, and the FY 2000 results were summed up. In the study of the development of the system, studies were made not only on the lowering of heating, cost reduction and heightening of speed, but on the mechanism and control by which machine natural vibration can relatively be cut off, technology of damping for cutting vibration, technology to meet the deformation, etc. by cutting loads, sliding loads, and acceleration of accelerating/decelerating, technology to reduce the machine weight, etc. In the study of the basic technology of linear motor, the finite element method analysis was conducted on the typical linear motor. Concerning the control system, specs were studied which can deal with natural vibration and cutting vibration of the machine system. As to the development of the steel scale type linear encoder, scale sample for evaluation of basic characteristics was designed/trially manufactured. In the study of the detection optical system, the design/trial manufacture of photodiode array were made. (NEDO)

  2. Partially non-linear stimulation intensity-dependent effects of direct current stimulation on motor cortex excitability in humans.

    Science.gov (United States)

    Batsikadze, G; Moliadze, V; Paulus, W; Kuo, M-F; Nitsche, M A

    2013-04-01

    Transcranial direct current stimulation (tDCS) of the human motor cortex at an intensity of 1 mA with an electrode size of 35 cm(2) has been shown to induce shifts of cortical excitability during and after stimulation. These shifts are polarity-specific with cathodal tDCS resulting in a decrease and anodal stimulation in an increase of cortical excitability. In clinical and cognitive studies, stronger stimulation intensities are used frequently, but their physiological effects on cortical excitability have not yet been explored. Therefore, here we aimed to explore the effects of 2 mA tDCS on cortical excitability. We applied 2 mA anodal or cathodal tDCS for 20 min on the left primary motor cortex of 14 healthy subjects. Cathodal tDCS at 1 mA and sham tDCS for 20 min was administered as control session in nine and eight healthy subjects, respectively. Motor cortical excitability was monitored by transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs) from the right first dorsal interosseous muscle. Global corticospinal excitability was explored via single TMS pulse-elicited MEP amplitudes, and motor thresholds. Intracortical effects of stimulation were obtained by cortical silent period (CSP), short latency intracortical inhibition (SICI) and facilitation (ICF), and I wave facilitation. The above-mentioned protocols were recorded both before and immediately after tDCS in randomized order. Additionally, single-pulse MEPs, motor thresholds, SICI and ICF were recorded every 30 min up to 2 h after stimulation end, evening of the same day, next morning, next noon and next evening. Anodal as well as cathodal tDCS at 2 mA resulted in a significant increase of MEP amplitudes, whereas 1 mA cathodal tDCS decreased corticospinal excitability. A significant shift of SICI and ICF towards excitability enhancement after both 2 mA cathodal and anodal tDCS was observed. At 1 mA, cathodal tDCS reduced single-pulse TMS-elicited MEP amplitudes and shifted SICI

  3. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities

    NARCIS (Netherlands)

    Mujawar, L.H.; Norde, W.; Amerongen, van A.

    2013-01-01

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost

  4. Quantitative assessment of contact and non-contact lateral force calibration methods for atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tran Khac, Bien Cuong; Chung, Koo-Hyun, E-mail: khchung@ulsan.ac.kr

    2016-02-15

    Atomic Force Microscopy (AFM) has been widely used for measuring friction force at the nano-scale. However, one of the key challenges faced by AFM researchers is to calibrate an AFM system to interpret a lateral force signal as a quantifiable force. In this study, five rectangular cantilevers were used to quantitatively compare three different lateral force calibration methods to demonstrate the legitimacy and to establish confidence in the quantitative integrity of the proposed methods. The Flat-Wedge method is based on a variation of the lateral output on a surface with flat and changing slopes, the Multi-Load Pivot method is based on taking pivot measurements at several locations along the cantilever length, and the Lateral AFM Thermal-Sader method is based on determining the optical lever sensitivity from the thermal noise spectrum of the first torsional mode with a known torsional spring constant from the Sader method. The results of the calibration using the Flat-Wedge and Multi-Load Pivot methods were found to be consistent within experimental uncertainties, and the experimental uncertainties of the two methods were found to be less than 15%. However, the lateral force sensitivity determined by the Lateral AFM Thermal-Sader method was found to be 8–29% smaller than those obtained from the other two methods. This discrepancy decreased to 3–19% when the torsional mode correction factor for an ideal cantilever was used, which suggests that the torsional mode correction should be taken into account to establish confidence in Lateral AFM Thermal-Sader method. - Highlights: • Quantitative assessment of three lateral force calibration methods for AFM. • Advantages and disadvantages of three different lateral force calibration method. • Implementation of Multi-Load Pivot method as non-contact calibration technique. • The torsional mode correction for Lateral AFM Thermal-Sader method.

  5. Corneal surface temperature change as the mode of stimulation of the non-contact corneal aesthesiometer.

    Science.gov (United States)

    Murphy, P J; Morgan, P B; Patel, S; Marshall, J

    1999-05-01

    The non-contact corneal aesthesiometer (NCCA) assesses corneal sensitivity by using a controlled pulse of air, directed at the corneal surface. The purpose of this paper was to investigate whether corneal surface temperature change was a component in the mode of stimulation. Thermocouple experiment: A simple model corneal surface was developed that was composed of a moistened circle of filter paper placed on a thermocouple and mounted on a glass slide. The temperature change produced by different stimulus pressures was measured for five different ambient temperatures. Thermal camera experiment: Using a thermal camera, the corneal surface temperature change was measured in nine young, healthy subjects after exposure to different stimulus air pulses. Pulse duration was set at 0.9 s but was varied in pressure from 0.5 to 3.5 millibars. Thermocouple experiment: An immediate drop in temperature was detected by the thermocouple as soon as the air flow was incident on the filter paper. A greater temperature change was produced by increasing the pressure of the incident air flow. A relationship was found and a calibration curve plotted. Thermal camera experiment: For each subject, a drop in surface temperature was detected at each stimulus pressure. Furthermore, as the stimulus pressure increased, the induced reduction in temperature also increased. A relationship was found and a calibration curve plotted. The NCCA air-pulse stimulus was capable of producing a localized temperature change on the corneal surface. The principal mode of corneal nerve stimulation, by the NCCA air pulse, was the rate of temperature change of the corneal surface.

  6. Evaluation techniques of accuracy characteristics for non-contact photonic track inspection system

    Science.gov (United States)

    Popov, Dmitry V.; Ryabichenko, Roman B.; Krivosheina, Elena A.

    2005-06-01

    The most important task in Moscow metro is increasing safety of railway traffic. For safety purposes six track parameters are measured in Moscow Metro with help of track measurement car. Equipment mounted on this car works only in contact mode and doesn't provide modem requirements for accuracy. Also important task is measurement at high speeds, but contact technology limits speed of movement up to 25mph on rail switches. Current system can't measure in real-time mode. For decision of these field of tasks non-contact photonic measurement system (KSIR) is constructed. The KSIR works at speeds up to 70 mph and measure seven track parameters. The KSIR contains four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FTP); contact rail measurement (FKR); speed, level and car locating (USI). KSIR contains five CCD matrix cameras, four line CCD cameras, five infrared stripe lasers and four spot infrared lasers. Laser forms shape on the rail. CCD-camera acquires rail image and transfers it into the digital signal processor which produces preliminary calculation ofrail shape. Then image is transferred into the central computer to calculate values of rail characteristics. Angles between photonic unit and rail bring distortions in images from cameras. Additional distortions are caused by short-focus optics and small distance between camera and track. This distance is limited by structure clearance. The transformation algorithms for distortions elimination are applied. It's based on surfaces spline-approximation. As a result the KSIR calculates coefficients of approximating polynomials. The calibration is performed for checking accuracy of measurement in BFSM, FTP and FKR units. Evaluation techniques of accuracy characteristics are considered.

  7. Non-contact temperature Raman measurement in YSZ and alumina ceramics

    Science.gov (United States)

    Thapa, Juddha; Chorpening, Benjamin T.; Buric, Michael P.

    2018-02-01

    Yttria-stabilized zirconia (YSZ: ZrO2 + Y2O3) and alumina (Al2O3) are widely used in high-temperature applications due to their high-temperature stability, low thermal conductivity, and chemical inertness. Alumina is used extensively in engineered ceramic applications such as furnace tubes and thermocouple protection tubes, while YSZ is commonly used in thermal barrier coatings on turbine blades. Because they are already often found in high temperature and combustion applications, these two substances have been compared as candidates for Raman thermometry in high-temperature energy-related applications. Both ceramics were used with as-received rough surfaces, i.e., without polishing or modification. This closely approximates surface conditions in practical high-temperature situations. A single-line argon ion laser at 488nm was used to excite the materials inside a cylindrical furnace while measuring Raman spectra with a fixed-grating spectrometer. The shift in the peak positions of the most intense A1g peak at 418cm-1 (room temperature position) of alumina ceramic and relatively more symmetric Eg peak at 470cm-1 (room temperature position) of YSZ were measured and reported along with a thermocouple-derived reference temperature up to about 1000°C. This study showed that alumina and YSZ ceramics can be used in high-temperature Raman thermometry with an accuracy of 4.54°C and 10.5°C average standard deviations respectively over the range of about 1000°C. We hope that this result will guide future researchers in selecting materials and utilizing Raman non-contact temperature measurements in harsh environments.

  8. Clinical evaluation of the Keeler Pulsair 3000 non-contact tonometer.

    Science.gov (United States)

    Lawson-Kopp, Wendy; DeJong, Amy; Yudcovitch, Lorne; Williams, Salisa; Kohl, Paul; Yolton, Robert L

    2002-02-01

    The Keeler Pulsair 3000 is a recently introduced non-contact tonometer that is especially useful for children and those for whom sitting at a slit-lamp or table-mounted unit would be difficult. In this project, intraocular pressures (IOPs) measured by Keeler Pulsair 3000 and Goldmann tonometers were compared to assess validity and reliability of the Pulsair 3000 data. Two Pulsair 3000 IOPs (each the mean of four individual air-puff readings) and two Goldmann IOPs were measured for each eye of 113 subjects. Subjects were also asked which measurement technique they preferred. IOPs ranged from 9 to 28 mmHg. Correlations between the two Goldmann IOPs measured for the right and left eyes were 0.98 and 0.97, respectively. These values are higher than correlations between Pulsair and Goldmann measurements (0.86 to 0.91). Pulsair 3000 IOPs were slightly above Goldmann values for pressures of less than 15 mmHg and slightly below for IOPs greater than 15 mmHg. Extrapolation to a Goldmann IOP of 30 mmHg suggests the Pulsair 3000 would read about 6% (1.7 mmHg) too low at this IOP. Eight eyes (7%) had differences between Pulsair 3000 and Goldmann IOP readings of 5.0 mmHg or more. Single outlier pressures accounted for these differences in three out of the eight eyes. In the range of 10 to 24 mmHg, the Pulsair 3000 tonometer produced IOP readings that corresponded well with Goldmann values for most eyes and was preferred by the majority of subjects who indicated a preference. The Pulsair 3000 is relatively easy to use by technicians and has numerous special applications in optometric practice (e.g. measuring IOPs for pediatric patients and those with compromised corneas).

  9. Effects of puff times on intraocular pressure agreement between non-contact and Goldmann applanation tonometers

    Directory of Open Access Journals (Sweden)

    Ibrahim Toprak

    2014-07-01

    Full Text Available AIM: To compare intraocular pressure(IOPvalues obtained from two different puff modes of Canon TX-F non-contact tonometer(NCTand Goldmann applanation tonometer(GATin patients with primary open angle glaucoma(POAG. METHODS: The study group comprised 55 right eyes of 55 patients with a confirmed diagnosis of POAG, which were under treatment. All patients underwent detailed ophthalmological examinations, optical coherence tomography imaging and automated perimetry. Intraocular pressure measurements were performed using 1-puff mode of NCT(NCT1, 3-puffs mode of NCT(NCT3and GAT with 5 minutes intervals in order. RESULTS: Fifty-five eyes of 55 patients with POAG(mean age of 64.1±8.1 yearswere enrolled into the study. NCT1 and NCT3 gave similar IOP values when compared with GAT measurements(14.22±3.42, 14.28±3.29, 14.66±3.49mmHg respectively, P=0.291. Intertonometer agreement was assessed using the Bland-Altman method. The 95% limits of agreement(LoAfor NCT1-GAT, NCT3-GAT and NCT1-NCT3 comparisons were -4.9 to +4.4mmHg, -4.1 to +3.4mmHg, and -3.4 to +3.3mmHg respectively.CONCLUSION: Although IOP measurements obtained from two puff modes of NCT and GAT showed similar values, wide range of LoA might restrict use of NCT1, NCT3 and GAT interchangeably in POAG patients.

  10. Non-contact tonometry synchronized with cardiac rhythm and its relationship with blood pressure.

    Science.gov (United States)

    Queirós, A; González-Méijome, J M; Fernandes, P; Jorge, J; Almeida, J B; Parafita, M A

    2006-07-01

    The main objectives of this study were to determine the differences between non-synchronized intraocular pressure (IOP_N) and intraocular pressure readings synchronized with cardiac pulse and try to determine if these parameters are related to blood pressure values. One hundred and sixty-five right eyes from 165 volunteers (107 females, 58 males) aged from 19 to 73 years (mean +/- S.D., 29.93 +/- 11.17) were examined with the Nidek NT-4000, a new non-contact tonometer that allows the measurement of IOP synchronized with the cardiac rhythm. IOP measurements in the four different modes of synchronization were taken in a randomized order. Three measures of each parameter were taken and then averaged. The blood pressure was determined three times with a portable manometer and mean values of systolic and diastolic pressure and the pulse rate were computed. Mean arterial pressure (MAP) was determined as being 1/3 of systolic plus 2/3 of diastolic blood pressure. The mean +/- S.D. values for the standard intraocular pressure (IOP_N: 14.76 +/- 2.86), intraocular pressure in the systolic instant or peak (IOP_P: 14.99 +/- 2.85), intraocular pressure in the middle instant between heartbeats or middle (IOP_M: 14.68 +/- 2.76), and intraocular pressure in the diastolic instant or bottom (IOP_B: 13.86 +/- 2.61) were obtained. The IOP_P was higher than the remaining values. A significant difference in mean IOP existed between IOP_B and the remaining modes of measuring (p non-synchronized and the remaining synchronized parameters in a significant way. Other than a weak association with MAP, no significant correlation between IOP and BP was found. The measurements of IOP readings for the three modes are consistent with timings during the cardiac cycle and IOP pulse cycle.

  11. Quantitative assessment of contact and non-contact lateral force calibration methods for atomic force microscopy

    International Nuclear Information System (INIS)

    Tran Khac, Bien Cuong; Chung, Koo-Hyun

    2016-01-01

    Atomic Force Microscopy (AFM) has been widely used for measuring friction force at the nano-scale. However, one of the key challenges faced by AFM researchers is to calibrate an AFM system to interpret a lateral force signal as a quantifiable force. In this study, five rectangular cantilevers were used to quantitatively compare three different lateral force calibration methods to demonstrate the legitimacy and to establish confidence in the quantitative integrity of the proposed methods. The Flat-Wedge method is based on a variation of the lateral output on a surface with flat and changing slopes, the Multi-Load Pivot method is based on taking pivot measurements at several locations along the cantilever length, and the Lateral AFM Thermal-Sader method is based on determining the optical lever sensitivity from the thermal noise spectrum of the first torsional mode with a known torsional spring constant from the Sader method. The results of the calibration using the Flat-Wedge and Multi-Load Pivot methods were found to be consistent within experimental uncertainties, and the experimental uncertainties of the two methods were found to be less than 15%. However, the lateral force sensitivity determined by the Lateral AFM Thermal-Sader method was found to be 8–29% smaller than those obtained from the other two methods. This discrepancy decreased to 3–19% when the torsional mode correction factor for an ideal cantilever was used, which suggests that the torsional mode correction should be taken into account to establish confidence in Lateral AFM Thermal-Sader method. - Highlights: • Quantitative assessment of three lateral force calibration methods for AFM. • Advantages and disadvantages of three different lateral force calibration method. • Implementation of Multi-Load Pivot method as non-contact calibration technique. • The torsional mode correction for Lateral AFM Thermal-Sader method.

  12. Development of a non-contact diagnostic tool for high power lasers

    Science.gov (United States)

    Simmons, Jed A.; Guttman, Jeffrey L.; McCauley, John

    2016-03-01

    High power lasers in excess of 1 kW generate enough Rayleigh scatter, even in the NIR, to be detected by silicon based sensor arrays. A lens and camera system in an off-axis position can therefore be used as a non-contact diagnostic tool for high power lasers. Despite the simplicity of the concept, technical challenges have been encountered in the development of an instrument referred to as BeamWatch. These technical challenges include reducing background radiation, achieving high signal to noise ratio, reducing saturation events caused by particulates crossing the beam, correcting images to achieve accurate beam width measurements, creating algorithms for the removal of non-uniformities, and creating two simultaneous views of the beam from orthogonal directions. Background radiation in the image was reduced by the proper positioning of the back plane and the placement of absorbing materials on the internal surfaces of BeamWatch. Maximizing signal to noise ratio, important to the real-time monitoring of focus position, was aided by increasing lens throughput. The number of particulates crossing the beam path was reduced by creating a positive pressure inside BeamWatch. Algorithms in the software removed non-uniformities in the data prior to generating waist width, divergence, BPP, and M2 results. A dual axis version of BeamWatch was developed by the use of mirrors. By its nature BeamWatch produced results similar to scanning slit measurements. Scanning slit data was therefore taken and compared favorably with BeamWatch results.

  13. Non-contact detection of cardiac rate based on visible light imaging device

    Science.gov (United States)

    Zhu, Huishi; Zhao, Yuejin; Dong, Liquan

    2012-10-01

    We have developed a non-contact method to detect human cardiac rate at a distance. This detection is based on the general lighting condition. Using the video signal of human face region captured by webcam, we acquire the cardiac rate based on the PhotoPlethysmoGraphy theory. In this paper, the cardiac rate detecting method is mainly in view of the blood's different absorptivities of the lights various wavelengths. Firstly, we discompose the video signal into RGB three color signal channels and choose the face region as region of interest to take average gray value. Then, we draw three gray-mean curves on each color channel with time as variable. When the imaging device has good fidelity of color, the green channel signal shows the PhotoPlethysmoGraphy information most clearly. But the red and blue channel signals can provide more other physiological information on the account of their light absorptive characteristics of blood. We divide red channel signal by green channel signal to acquire the pulse wave. With the passband from 0.67Hz to 3Hz as a filter of the pulse wave signal and the frequency spectrum superimposed algorithm, we design frequency extracted algorithm to achieve the cardiac rate. Finally, we experiment with 30 volunteers, containing different genders and different ages. The results of the experiments are all relatively agreeable. The difference is about 2bmp. Through the experiment, we deduce that the PhotoPlethysmoGraphy theory based on visible light can also be used to detect other physiological information.

  14. Non-contact Real-time heart rate measurements based on high speed circuit technology research

    Science.gov (United States)

    Wu, Jizhe; Liu, Xiaohua; Kong, Lingqin; Shi, Cong; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin

    2015-08-01

    In recent years, morbidity and mortality of the cardiovascular or cerebrovascular disease, which threaten human health greatly, increased year by year. Heart rate is an important index of these diseases. To address this status, the paper puts forward a kind of simple structure, easy operation, suitable for large populations of daily monitoring non-contact heart rate measurement. In the method we use imaging equipment video sensitive areas. The changes of light intensity reflected through the image grayscale average. The light change is caused by changes in blood volume. We video the people face which include the sensitive areas (ROI), and use high-speed processing circuit to save the video as AVI format into memory. After processing the whole video of a period of time, we draw curve of each color channel with frame number as horizontal axis. Then get heart rate from the curve. We use independent component analysis (ICA) to restrain noise of sports interference, realized the accurate extraction of heart rate signal under the motion state. We design an algorithm, based on high-speed processing circuit, for face recognition and tracking to automatically get face region. We do grayscale average processing to the recognized image, get RGB three grayscale curves, and extract a clearer pulse wave curves through independent component analysis, and then we get the heart rate under the motion state. At last, by means of compare our system with Fingertip Pulse Oximeter, result show the system can realize a more accurate measurement, the error is less than 3 pats per minute.

  15. Automatic detection of whole night snoring events using non-contact microphone.

    Directory of Open Access Journals (Sweden)

    Eliran Dafna

    Full Text Available OBJECTIVE: Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology. DESIGN: Sounds during polysomnography (PSG were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events. PATIENTS: Sixty-seven subjects (age 52.5 ± 13.5 years, BMI 30.8 ± 4.7 kg/m(2, m/f 40/27 referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects. MEASUREMENTS AND RESULTS: To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental. A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore and specificity of 98.3% (noise as noise. CONCLUSIONS: Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients.

  16. Non-contact hematoma damage and healing assessment using reflectance photoplethysmographic imaging

    Science.gov (United States)

    Amelard, Robert; Pfisterer, Kaylen J.; Clausi, David A.; Wong, Alexander

    2016-03-01

    Impact trauma may cause a hematoma, which is the leakage of venous blood into surrounding tissues. Large hematomas can be dangerous as they may inhibit local blood ow. Hematomas are often diagnosed visually, which may be problematic if the hematoma leaks deeper than the visible penetration depth. Furthermore, vascular wound healing is often monitored at home without the aid of a clinician. We therefore investigated the use of near infrared (NIR) re ectance photoplethysmographic imaging (PPGI) to assess vascular damage resulting from a hematoma, and monitor the healing process. In this case study, the participant experienced internal vascular damage in the form of a hematoma. Using a PPGI system with dual-mode temporally coded illumination for ambient-agnostic data acquisition and mounted optical elements, the tissue was illuminated with a spatially uniform irradiance pattern of 850 nm wavelength light for increased tissue penetration and high oxy-to-deoxyhemoglobin absorption ratio. Initial and follow-up PPGI data collection was performed to assess vascular damage and healing. The tissue PPGI sequences were spectrally analyzed, producing spectral maps of the tissue area. Experimental results show that spatial differences in spectral information can be observed around the damaged area. In particular, the damaged site exhibited lower pulsatility than the surrounding healthy tissue. This pulsatility was largely restored in the follow-up data, suggesting that the tissue had undergone vascular healing. These results indicate that hematomas can be assessed and monitored in a non-contact visual manner, and suggests that PPGI can be used for tissue health assessment, with potential extensions to peripheral vascular disease.

  17. Non-contact flow gauging for the extension and development of rating curves

    Science.gov (United States)

    Perks, Matthew; Large, Andy; Russell, Andy

    2015-04-01

    Accurate measurement of river discharge is fundamental to understanding hydrological processes, associated hazards and ecological responses within fluvial systems. Established protocols for determining river discharge are partial, predominantly invasive and logistically difficult during high flows. There is demand for new methods for accurate quantification of flow velocity under high-flow/flood conditions to in turn enable better post-event reconstruction of peak discharge. As a consequence considerable effort has been devoted to the development of innovative technologies for the representation of flow in open channels. Remotely operated fixed and mobile systems capable of providing quantitative estimates of instantaneous and time-averaged flow characteristics using non-contact methods has been a major development. Amongst the new approaches for stand-alone continuous monitoring of surface flows is Large Scale Particle Image Velocimetry (LSPIV). Here we adapt the LSPIV concept, to provide continuous discharge measurements in non-uniform channels with complex flow conditions. High Definition videos (1080p; 30fps) of the water surface are acquired at 5 minute intervals. The image is rectified to correct for perspective distortion using a new, open source tool which minimises errors resulting from oblique image capture. Naturally occurring artefacts on the water surface (e.g. bubbles, debris, etc.) are tracked with the Kanade-Lucas-Tomasi (KLT) algorithm. The data generated is in the form of a complex surface water velocity field which can be interrogated to extract a range of hydrological information such as the streamwise velocity at a cross-section of interest, or even allow the interrogation of hydrodynamic flow structures. Here we demonstrate that this approach is capable of generating river discharge data comparable to concurrent measurements made using existing, accepted technologies (e.g. ADCP). The outcome is better constraint and extension of rating curves

  18. Contact Versus Non-Contact Measurement of a Helicopter Main Rotor Composite Blade

    Science.gov (United States)

    Luczak, Marcin; Dziedziech, Kajetan; Vivolo, Marianna; Desmet, Wim; Peeters, Bart; Van der Auweraer, Herman

    2010-05-01

    The dynamic characterization of lightweight structures is particularly complex as the impact of the weight of sensors and instrumentation (cables, mounting of exciters…) can distort the results. Varying mass loading or constraint effects between partial measurements may determine several errors on the final conclusions. Frequency shifts can lead to erroneous interpretations of the dynamics parameters. Typically these errors remain limited to a few percent. Inconsistent data sets however can result in major processing errors, with all related consequences towards applications based on the consistency assumption, such as global modal parameter identification, model-based damage detection and FRF-based matrix inversion in substructuring, load identification and transfer path analysis [1]. This paper addresses the subject of accuracy in the context of the measurement of the dynamic properties of a particular lightweight structure. It presents a comprehensive comparative study between the use of accelerometer, laser vibrometer (scanning LDV) and PU-probe (acoustic particle velocity and pressure) measurements to measure the structural responses, with as final aim the comparison of modal model quality assessment. The object of the investigation is a composite material blade from the main rotor of a helicopter. The presented results are part of an extensive test campaign performed with application of SIMO, MIMO, random and harmonic excitation, and the use of the mentioned contact and non-contact measurement techniques. The advantages and disadvantages of the applied instrumentation are discussed. Presented are real-life measurement problems related to the different set up conditions. Finally an analysis of estimated models is made in view of assessing the applicability of the various measurement approaches for successful fault detection based on modal parameters observation as well as in uncertain non-deterministic numerical model updating.

  19. Contact Versus Non-Contact Measurement of a Helicopter Main Rotor Composite Blade

    International Nuclear Information System (INIS)

    Luczak, Marcin; Dziedziech, Kajetan; Peeters, Bart; Van der Auweraer, Herman; Vivolo, Marianna; Desmet, Wim

    2010-01-01

    The dynamic characterization of lightweight structures is particularly complex as the impact of the weight of sensors and instrumentation (cables, mounting of exciters...) can distort the results. Varying mass loading or constraint effects between partial measurements may determine several errors on the final conclusions. Frequency shifts can lead to erroneous interpretations of the dynamics parameters. Typically these errors remain limited to a few percent. Inconsistent data sets however can result in major processing errors, with all related consequences towards applications based on the consistency assumption, such as global modal parameter identification, model-based damage detection and FRF-based matrix inversion in substructuring, load identification and transfer path analysis [1]. This paper addresses the subject of accuracy in the context of the measurement of the dynamic properties of a particular lightweight structure. It presents a comprehensive comparative study between the use of accelerometer, laser vibrometer (scanning LDV) and PU-probe (acoustic particle velocity and pressure) measurements to measure the structural responses, with as final aim the comparison of modal model quality assessment. The object of the investigation is a composite material blade from the main rotor of a helicopter. The presented results are part of an extensive test campaign performed with application of SIMO, MIMO, random and harmonic excitation, and the use of the mentioned contact and non-contact measurement techniques. The advantages and disadvantages of the applied instrumentation are discussed. Presented are real-life measurement problems related to the different set up conditions. Finally an analysis of estimated models is made in view of assessing the applicability of the various measurement approaches for successful fault detection based on modal parameters observation as well as in uncertain non-deterministic numerical model updating.

  20. Non-Contact Acousto-Thermal Signatures of Plastic Deformation in TI-6AL-4V

    Science.gov (United States)

    Welter, J. T.; Malott, G.; Schehl, N.; Sathish, S.; Jata, K. V.; Blodgett, M. P.

    2010-02-01

    Plastic deformation introduces changes in a material which include increases in: dislocations, strains, residual stress, and yield stress. However, these changes have a very small impact on the material properties such as elastic modulus, conductivity and ultrasonic wave speed. This is due to the fact that interatomic forces govern these properties, and they are not affected by plastic deformation to any large degree. This is evident from the fact that the changes in electrical resistance and ultrasonic velocity in plastically deformed and virgin samples are very small and can only be determined by highly controlled experiments. Except for X-ray diffraction, there are no direct nondestructive methods for measuring strain and the residual stress. This paper presents an application of the non-contact acousto-thermal signature (NCATS) NDE methodology to detect plastic deformation in flat dog bone Ti-6Al-4V samples. Results of the NCATS measurements on samples subjected to incremental amounts of plastic deformation are presented. The maximum temperature attained by the sample due to acoustic excitation is found to be sensitive to the amount of plastic strain. It is observed that the temperature induced by acoustic excitation increases to a peak followed by a decrease to failure. The maximum temperature peak occurs at plastic strains of 12-14%. It is observed that there is a correlation between the peak in maximum temperature rise and the strain at the experimentally determined ultimate tensile strength. A microstructural based explanation for this will be presented. The results are discussed in reference to utilizing this technique for detection and evaluation of plastic deformation.

  1. A Model for Analyzing a Five-Phase Fractional-Slot Permanent Magnet Tubular Linear Motor with Modified Winding Function Approach

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2016-01-01

    Full Text Available This paper presents a model for analyzing a five-phase fractional-slot permanent magnet tubular linear motor (FSPMTLM with the modified winding function approach (MWFA. MWFA is a fast modeling method and it gives deep insight into the calculations of the following parameters: air-gap magnetic field, inductances, flux linkages, and detent force, which are essential in modeling the motor. First, using a magnetic circuit model, the air-gap magnetic density is computed from stator magnetomotive force (MMF, flux barrier, and mover geometry. Second, the inductances, flux linkages, and detent force are analytically calculated using modified winding function and the air-gap magnetic density. Finally, a model has been established with the five-phase Park transformation and simulated. The calculations of detent force reveal that the end-effect force is the main component of the detent force. This is also proven by finite element analysis on the motor. The accuracy of the model is validated by comparing with the results obtained using semianalytical method (SAM and measurements to analyze the motor’s transient characteristics. In addition, the proposed method requires less computation time.

  2. Torque Ripple Reduction of a Novel Modular Arc-Linear Flux-Switching Permanent-Magnet Motor with Rotor Step Skewing

    Directory of Open Access Journals (Sweden)

    Xiangdong Liu

    2016-05-01

    Full Text Available A novel modular arc-linear flux-switching permanent-magnet motor (MAL-FSPM used for scanning system instead of reduction gearboxes and kinematic mechanisms is proposed and researched in this paper by the finite element method (FEM. The MAL-FSPM combines characteristics of flux-switching permanent-magnet motor and linear motor and can realize the direct driving and limited angular movement. Structure and operation principle of the MAL-FSPM are analyzed. Cogging torque model of the MAL-FSPM is established. The characteristics of cogging torque and torque ripple are investigated for: (1 distance (dend between left end of rotor and left end of stator is more than two rotor tooth pitch (τp; and (2 dend is less than two rotor tooth pitch. Cogging torque is an important component of torque ripple and the period ratio of the cogging torque to the back electromotive force (EMF equals one for the MAL-FSPM before optimization. In order to reduce the torque ripple as much as possible and affect the back EMF as little as possible, influence of period ratio of cogging torque to back EMF on rotor step skewing is investigated. Rotor tooth width and stator slot open width are optimized to increase the period ratio of cogging torque to back EMF. After the optimization, torque ripple is decreased by 79.8% for dend > τp and torque ripple is decreased by 49.7% for dend < τp. Finally, 3D FEM model is established to verify the 2D results.

  3. An adaptive Kalman filter approach for cardiorespiratory signal extraction and fusion of non-contacting sensors.

    Science.gov (United States)

    Foussier, Jerome; Teichmann, Daniel; Jia, Jing; Misgeld, Berno; Leonhardt, Steffen

    2014-05-09

    Extracting cardiorespiratory signals from non-invasive and non-contacting sensor arrangements, i.e. magnetic induction sensors, is a challenging task. The respiratory and cardiac signals are mixed on top of a large and time-varying offset and are likely to be disturbed by measurement noise. Basic filtering techniques fail to extract relevant information for monitoring purposes. We present a real-time filtering system based on an adaptive Kalman filter approach that separates signal offsets, respiratory and heart signals from three different sensor channels. It continuously estimates respiration and heart rates, which are fed back into the system model to enhance performance. Sensor and system noise covariance matrices are automatically adapted to the aimed application, thus improving the signal separation capabilities. We apply the filtering to two different subjects with different heart rates and sensor properties and compare the results to the non-adaptive version of the same Kalman filter. Also, the performance, depending on the initialization of the filters, is analyzed using three different configurations ranging from best to worst case. Extracted data are compared with reference heart rates derived from a standard pulse-photoplethysmographic sensor and respiration rates from a flowmeter. In the worst case for one of the subjects the adaptive filter obtains mean errors (standard deviations) of -0.2 min(-1) (0.3 min(-1)) and -0.7 bpm (1.7 bpm) (compared to -0.2 min(-1) (0.4 min(-1)) and 42.0 bpm (6.1 bpm) for the non-adaptive filter) for respiration and heart rate, respectively. In bad conditions the heart rate is only correctly measurable when the Kalman matrices are adapted to the target sensor signals. Also, the reduced mean error between the extracted offset and the raw sensor signal shows that adapting the Kalman filter continuously improves the ability to separate the desired signals from the raw sensor data. The average total computational time needed

  4. Non-contact test of coating by means of laser-induced ultrasonic excitation and holographic sound representation

    International Nuclear Information System (INIS)

    Crostack, H.A.; Pohl, K.Y.; Radtke, U.

    1991-01-01

    In order to circumvent the problems of introducing and picking off sound, which occur in conventional ultrasonic testing, a completely non-contact test process was developed. The ultrasonic surface wave required for the test is generated without contact by absorption of laser beams. The recording of the ultrasound also occurs by a non-contact holographic interferometry technique, which permits a large scale representation of the sound. Using the example of MCrAlY and ZrO 2 layers, the suitability of the process for testing thermally sprayed coatings on metal substrates is identified. The possibilities and limits of the process for the detection and description of delamination and cracks are shown. (orig.) [de

  5. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    Science.gov (United States)

    Trichopoulos, Georgios C.

    . Additionally, a butterfly-shaped antenna layout is introduced that enables broadband imaging. The alternative design presented here, allows for video-rate imaging in the 0.6--1.2 THz band and maintains a small antenna footprint, resulting in densely packed FPAs. In both antenna designs, we optimize the impedance matching between the antennas and the integrated electronic devices, thus achieving optimum responsivity levels for high sensitivity and low noise performance. Subsequently, we present the design details of the first THz camera and the first THz camera images captured. With the realized THz camera, imaging of concealed objects is achieved with space. Thus, the hybrid electromagnetic model allows fast and accurate design of THz antennas and modeling of the complete THz imaging system. Finally, motivated by the novel THz antenna layouts and the quasioptical techniques, we developed a novel non-contact probe measurement method for on-chip device characterization. In the THz regime, traditional contact probes are too small and fragile, thus inhibiting accurate and reliable circuit measurements. By integrating the device under test (DUT) with THz antennas that act as the measurement probes, we may couple the incident and reflected signal from and to the network analyzer without residing to any physical connection.

  6. Non-contact transportation system of small objects using Ultrasonic Waveguides

    International Nuclear Information System (INIS)

    Nakamura, K; Koyama, D

    2012-01-01

    A transportation system for small object or fluid without contact is investigated being based on ultrasonic levitation. Small objects are suspended against gravity at the nodal points in ultrasonic pressure field due to the sound radiation force generated as the gradient of the energy density of the field. In this study, the trapped object is transported in the horizontal plane by introducing the spatial shift of the standing waves by the switching the lateral modes or travelling waves. The goal of the study is to establish a technology which can provide a total system with the flexibility in composing various transportation paths. Methods for linear/rotary stepping motions and continuous linear transportation are explained in this report. All the transportation tracks are composed of a bending vibrator and a reflector. The design for these acoustic cavity/waveguide is discussed.

  7. New sensor and non-contact geometrical survey for the vibrating wire technique

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Renan [Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP (Brazil); Junqueira Leão, Rodrigo, E-mail: rodrigo.leao@lnls.br [Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP (Brazil); Cernicchiaro, Geraldo [Brazilian Center for Research in Physics (CBPF), Rio de Janeiro, RJ (Brazil); Terenzi Neuenschwander, Regis; Citadini, James Francisco; Droher Rodrigues, Antônio Ricardo [Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP (Brazil)

    2016-03-01

    The tolerances for the alignment of the magnets in the girders of the next machine of the Brazilian Synchrotron Light Laboratory (LNLS), Sirius, are as small as 40 µm for translations and 0.2 mrad for rotations. Therefore, a novel approach to the well-known vibrating wire technique has been developed and tested for the precise fiducialization of magnets. The alignment bench consists of four commercial linear stages, a stretched wire, a commercial lock-in amplifier working with phase-locked loop (PLL), a coordinate measuring machine (CMM) and a vibration sensor for the wire. This novel sensor has been designed for a larger linear region of operation. For the mechanical metrology step of the fiducialization of quadrupoles an innovative technique, using the vision system of the CMM, is presented. While the work with pitch and yaw orientations is still ongoing with promising partial results, the system already presents an uncertainty level below 10 µm for translational alignment.

  8. Design and Parametric Study of the Magnetic Sensor for Position Detection in Linear Motor Based on Nonlinear Parametric model order reduction.

    Science.gov (United States)

    Paul, Sarbajit; Chang, Junghwan

    2017-07-01

    This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric variables of the sensor module are considered while developing the parametric study. The operation of the sensor module is based on the principle of the airgap flux density distribution detection by the Hall Effect IC. Therefore, the design objective is to achieve a peak flux density (PFD) greater than 0.1 T and total harmonic distortion (THD) less than 3%. To fulfill the constraint conditions, the specifications for the sensor module is achieved by using POD-DMD based reduced model. The POD-DMD based reduced model provides a platform to analyze the high number of design models very fast, with less computational burden. Finally, with the final specifications, the experimental prototype is designed and tested. Two different modes, 90° and 120° modes respectively are used to obtain the position information of the linear motor mover. The position information thus obtained are compared with that of the linear scale data, used as a reference signal. The position information obtained using the 120° mode has a standard deviation of 0.10 mm from the reference linear scale signal, whereas the 90° mode position signal shows a deviation of 0.23 mm from the reference. The deviation in the output arises due to the mechanical tolerances introduced into the specification during the manufacturing process. This provides a scope for coupling the reliability based design optimization in the design process as a future extension.

  9. [Comparison of tonometry with the Keeler air puff non-contact tonometer "Pulsair" and the Goldmann applanation tonometer].

    Science.gov (United States)

    Yücel, A A; Stürmer, J; Gloor, B

    1990-10-01

    Intraocular pressure (IOP) readings were performed with the Keeler Air-Puff Non-Contact Tonometer "Pulsair" in 126 patients before (NCT1) and after (NCT2) applanation-tonometry with the Goldmann device (GAT). For the whole population of 126 patients, in each of whom only one eye was selected, there was a significant difference of the mean IOP measurement, but the difference between the two measurement methods was only slightly significant when the NCT was applied before the GAT, and highly significant vice versa. Also the variation of the NCT-measurements was significantly larger than that for the GAT, while the before- and after GAT measurements had equal variations. If only the measurements under 18 mmHg mean GAT are taken into account (n = 101), the difference between GAT and NCT1 was not significant (p = 0.437), as opposed to the GAT-measurements above 18 mmHg, where a highly significant difference between the means was found (p = 0.0033). In most cases, the IOP-readings were underestimated using NCT. The Non Contact Tonometer "Pulsair" could be used for IOP-readings in patients with increased risk of infection, as well as in those with known allergic reactions to topical anesthetic agents, with poor or absent fixation ability, with corneal edema, and postoperative after anterior-segment surgery. The possibility of IOP-measurement in a reclined position is a true advantage of the Non-Contact Tonometer presented here. A measuring strategy for the above-mentioned applications is presented.

  10. Sugeno-Fuzzy Expert System Modeling for Quality Prediction of Non-Contact Machining Process

    Science.gov (United States)

    Sivaraos; Khalim, A. Z.; Salleh, M. S.; Sivakumar, D.; Kadirgama, K.

    2018-03-01

    Modeling can be categorised into four main domains: prediction, optimisation, estimation and calibration. In this paper, the Takagi-Sugeno-Kang (TSK) fuzzy logic method is examined as a prediction modelling method to investigate the taper quality of laser lathing, which seeks to replace traditional lathe machines with 3D laser lathing in order to achieve the desired cylindrical shape of stock materials. Three design parameters were selected: feed rate, cutting speed and depth of cut. A total of twenty-four experiments were conducted with eight sequential runs and replicated three times. The results were found to be 99% of accuracy rate of the TSK fuzzy predictive model, which suggests that the model is a suitable and practical method for non-linear laser lathing process.

  11. A novel non-contact profiler design for measuring synchrotron radiation mirrors

    International Nuclear Information System (INIS)

    Lin, Yao; Takacs, P.Z.; Furenlid, K.; DeBiasse, R.A.; Wang, Run-Wen

    1990-08-01

    A novel optical profiler is described in this paper for measurement of surface profiles of synchrotron radiation (SR) mirrors. The measurement is based on a combination of an optical heterodyne technique and a precise phase measurement procedure without a reference surface. A Zeeman two-frequency He-Ne laser is employed as the light source. The common-path optical system, which uses a birefringent lens as the beam splitter, minimizes the effects of air turbulence, sample vibration and temperature variation. A special autofocus system allows the profiler to measure the roughness and shape of a sample surface. The optical system is mounted on a large linear air-bearing slide, and is capable of scanning over distances covering the spatial period range from several microns to nearly one meter with a high measurement accuracy. 9 refs., 5 figs

  12. Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays(Asia-Pacific Symposium on Applied Electromagnetics and Mechanics (APSAEM08))

    OpenAIRE

    K., Nakaiwa; A., Yamada; K., Tashiro; H., Wakiwaka; Tamagawa-Seiki Co., Ltd; Shinshu University; Shinshu University; Shinshu University

    2009-01-01

    From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

  13. Effect of central corneal thickness on intraocular pressure and comparison of Topcon CT-80 non-contact tonometry with Goldmann applanation tonometry.

    Science.gov (United States)

    Mansoori, Tarannum; Balakrishna, Nagalla

    2018-03-01

    To compare intraocular pressure (IOP) measurements obtained with the Topcon CT-80 non-contact tonometer (NCT) and Goldmann applanation tonometer (GAT), in different ranges of IOP in normal and glaucoma subjects, and to assess the influence of central corneal thickness (CCT) on the IOP measurements in Asian Indian eyes. Four hundred and two eyes of 402 subjects (193 newly diagnosed primary open angle glaucoma [POAG] and 209 normal) were enrolled for this prospective study. For each eye, IOP was measured with GAT by a glaucoma specialist and NCT by a trained optometrist. The IOP values were compared among the tonometers in the three different IOP ranges (≤ 12 mmHg, 13-20 mmHg and ≥ 21 mmHg) using Bland-Altman graphs. Correlation between GAT and NCT was assessed by Pearson correlation co-efficient. CCT was measured with ultrasound pachymetry and its correlation with GAT and NCT was analysed using linear regression analysis. The mean paired difference of IOP between NCT and GAT was 1.556 ± 2.69 mmHg (r = 0.26, p = 0.006) at IOP range of ≤ 12 mmHg, -1.665 ± 2.6 mmHg (r = 0.51, p tonometer and that the IOP readings obtained with these tonometers are not interchangeable. © 2017 Optometry Australia.

  14. 25G compared with 20G vitrectomy under Resight non-contact wide-angle lenses for Terson syndrome.

    Science.gov (United States)

    Mao, Xinbang; You, Zhipeng

    2017-08-01

    The aim of the present study was to compare the effectiveness of 25G vitrectomy to standard 20G vitrectomy for treatment of Terson syndrome under Resight non-contact wide-angle lenses. This was a case-control study of 20 patients with Terson syndrome (study group) that underwent 25G vitrectomy under Resight non-contact wide-angle lenses, with those of 20 matched patients that underwent 20G vitrectomy (control group). Medical records were reviewed from between July 2011 and October 2013. Data included results of the Early Treatment Diabetic Retinopathy Study examination, ophthalmology B-scan ultrasonography and fundus photography. The mean age, follow-up time, the preoperative visual acuity of LogMAR and the preoperative intraocular pressure (IOP) were all comparable in the two groups (all P>0.05). There were statistically significant differences in postoperative visual acuity of LogMAR compared with preoperative visual acuity (Pcontact wide-angle lenses can achieve a significantly shorter operative time and lower post-operative IOP compared with 20G Vitrectomy.

  15. Design and Optimal Research of a Non-Contact Adjustable Magnetic Adhesion Mechanism for a Wall-Climbing Welding Robot

    Directory of Open Access Journals (Sweden)

    Minghui Wu

    2013-01-01

    Full Text Available Wall-climbing welding robots (WCWRs can replace workers in manufacturing and maintaining large unstructured equipment, such as ships. The adhesion mechanism is the key component of WCWRs. As it is directly related to the robot's ability in relation to adsorbing, moving flexibly and obstacle-passing. In this paper, a novel non-contact adjustably magnetic adhesion mechanism is proposed. The magnet suckers are mounted under the robot's axils and the sucker and wall are in non-contact. In order to pass obstacles, the sucker and the wheel unit can be pulled up and pushed down by a lifting mechanism. The magnetic adhesion force can be adjusted by changing the height of the gap between the sucker and the wall by the lifting mechanism. In order to increase the adhesion force, the value of the sucker's magnetic energy density (MED is maximized by optimizing the magnet sucker's structure parameters with a finite element method. Experiments prove that the magnetic adhesion mechanism has enough adhesion force and that the WCWR can complete wall-climbing work within a large unstructured environment.

  16. Influence of corneal thickness on comparative intraocular pressure measurements with Goldmann and non-contact tonometers in keratoconus.

    Science.gov (United States)

    Stabuc Silih, Mirna; Hawlina, Marko

    2003-12-01

    The influence of corneal thickness and curvature on the difference between intraocular pressure (IOP) measurements obtained with non-contact (NCT) and those with the Goldmann applanation tonometer (GAT) was studied in patients with keratoconus. We examined 113 patients with keratoconus. IOP was measured by the Canon TX 10 non-contact tonometer and the Goldmann tonometer, corneal curvature and thickness were obtained by Humphrey Automatic Refractometer Keratometer and Orbscan Version 3.0 Bausch & Lomb Surgical. The IOP measured by NCT was significantly lower than that measured by GAT. The mean pachymetry of the thinnest point was 423.15 +/- 98.43 microm for the right eyes and 426.7 +/- 93.88 microm for the left eyes. The difference between NCT-GAT and corneal thickness showed a significant negative correlation (r = - 0.427, p < 0.0001; t = - 3.677, p < 0.0001). Values of NCT measurements were significantly increasing with corneal thickness (F = 6.505, p < 0.0001 for right eyes and F = 4.37, p = 0.004 for left eyes), whilst GAT measurements did not show a significant influence of the corneal thickness. The keratometry had no effect on the difference between NCT-GAT measurements (t = 1.090, p = 0.278). The thin cornea has more influence on the measurement with NCT than GAT. The relative precision of NCT compared with GAT seems to be influenced by the corneal thickness.

  17. Dynamic Behavior Analysis of Non-Contacting Hydrodynamic Finger Seal Based on Fluid-Solid-Interaction Method

    Directory of Open Access Journals (Sweden)

    Su Hua

    2018-01-01

    Full Text Available Finger seal is an advanced compliant seal and can be utilized to separate high (HP and low pressure (LP zones in high speed rotating shaft environment. The work to be presented concerns the dynamic behavior of a repetitive section of a two-layer finger seal with high-and padded low-pressure laminates. The dynamic performance of the finger seal are analyzed by the coupled fluid-solid-interaction (FSI simulations. By using the commercial software ANSYS-CFX, the numerical simulation results of interactions between the gas flow and fingers structural deformation are described when the radial periodic excitation from the shaft applies to the finger seal. And the gas film loading capacity, gas film stiffness and leakage varied with time are put forward in different working conditions. Compared with the dynamic performance analysis results based on equivalent dynamic method, the FSI dynamic analysis shows some different characteristics which are more accordance with actual circumstance. Moreover, it is shown that under low pressure differential and high rotation speed the non-contacting finger seal with advance features both in sealing effectiveness and potential unlimited life span can be obtained by rational structure design. But for the non-contacting finger seal with circumferential convergent pad working in high pressure and low rotating speed conditions, it is difficult to improve the sealing performance by the way of changing the structure parameters of finger seal. It is because the high pressure plays a major role on this sealing situation.

  18. A New Method to Detect Driver Fatigue Based on EMG and ECG Collected by Portable Non-Contact Sensors

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2017-11-01

    Full Text Available Recently, detection and prediction on driver fatigue have become interest of research worldwide. In the present work, a new method is built to effectively evaluate driver fatigue based on electromyography (EMG and electrocardiogram (ECG collected by portable real-time and non-contact sensors. First, under the non-disturbance condition for driver’s attention, mixed physiological signals (EMG, ECG and artefacts are collected by non-contact sensors located in a cushion on the driver’s seat. EMG and ECG are effectively separated by FastICA, and de-noised by empirical mode decomposition (EMD. Then, three physiological features, complexity of EMG, complexity of ECG, and sample entropy (SampEn of ECG, are extracted and analysed. Principal components are obtained by principal components analysis (PCA and are used as independent variables. Finally, a mathematical model of driver fatigue is built, and the accuracy of the model is up to 91%. Moreover, based on the questionnaire, the calculation results of model are consistent with real fatigue felt by the participants. Therefore, this model can effectively detect driver fatigue.

  19. Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media

    Energy Technology Data Exchange (ETDEWEB)

    Ambroziński, Łukasz [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); AGH University of Science and Technology, Krakow 30059 (Poland); Pelivanov, Ivan, E-mail: ivanp3@uw.edu [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Faculty of Physics, Moscow State University, Moscow 119991 (Russian Federation); Song, Shaozhen; Yoon, Soon Joon; Gao, Liang; O' Donnell, Matthew [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Li, David [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Chemical Engineering, University of Washington Seattle, Washington 98195 (United States); Shen, Tueng T.; Wang, Ruikang K. [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Ophthalmology, University of Washington, Seattle, Washington 98104 (United States)

    2016-07-25

    A non-contact method for efficient, non-invasive excitation of mechanical waves in soft media is proposed, in which we focus an ultrasound (US) signal through air onto the surface of a medium under study. The US wave reflected from the air/medium interface provides radiation force to the medium surface that launches a transient mechanical wave in the transverse (lateral) direction. The type of mechanical wave is determined by boundary conditions. To prove this concept, a home-made 1 MHz piezo-ceramic transducer with a matching layer to air sends a chirped US signal centered at 1 MHz to a 1.6 mm thick gelatin phantom mimicking soft biological tissue. A phase-sensitive (PhS)-optical coherence tomography system is used to track/image the mechanical wave. The reconstructed transient displacement of the mechanical wave in space and time demonstrates highly efficient generation, thus offering great promise for non-contact, non-invasive characterization of soft media, in general, and for elasticity measurements in delicate soft tissues and organs in bio-medicine, in particular.

  20. The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry

    OpenAIRE

    Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

    2005-01-01

    Aims: To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT).

  1. Multi-Objective Optimization of Moving-magnet Linear Oscillatory Motor Using Response Surface Methodology with Quantum-Behaved PSO Operator

    Science.gov (United States)

    Lei, Meizhen; Wang, Liqiang

    2018-01-01

    To reduce the difficulty of manufacturing and increase the magnetic thrust density, a moving-magnet linear oscillatory motor (MMLOM) without inner-stators was Proposed. To get the optimal design of maximum electromagnetic thrust with minimal permanent magnetic material, firstly, the 3D finite element analysis (FEA) model of the MMLOM was built and verified by comparison with prototype experiment result. Then the influence of design parameters of permanent magnet (PM) on the electromagnetic thrust was systematically analyzed by the 3D FEA to get the design parameters. Secondly, response surface methodology (RSM) was employed to build the response surface model of the new MMLOM, which can obtain an analytical model of the PM volume and thrust. Then a multi-objective optimization methods for design parameters of PM, using response surface methodology (RSM) with a quantum-behaved PSO (QPSO) operator, was proposed. Then the way to choose the best design parameters of PM among the multi-objective optimization solution sets was proposed. Then the 3D FEA of the optimal design candidates was compared. The comparison results showed that the proposed method can obtain the best combination of the geometric parameters of reducing the PM volume and increasing the thrust.

  2. Optimum Performances for Non-Linear Finite Elements Model of 8/6 Switched Reluctance Motor Based on Intelligent Routing Algorithms

    Directory of Open Access Journals (Sweden)

    Chouaib Labiod

    2017-01-01

    Full Text Available This paper presents torque ripple reduction with speed control of 8/6 Switched Reluctance Motor (SRM by the determination of the optimal parameters of the turn on, turn off angles Theta_(on, Theta_(off, and the supply voltage using Particle Swarm Optimization (PSO algorithm and steady state Genetic Algorithm (ssGA. With SRM model, there is difficulty in the control relapsed into highly non-linear static characteristics. For this, the Finite Elements Method (FEM has been used because it is a powerful tool to get a model closer to reality. The mechanism used in this kind of machine control consists of a speed controller in order to determine current reference which must be produced to get the desired speed, hence, hysteresis controller is used to compare current reference with current measured up to achieve switching signals needed in the inverter. Depending on this control, the intelligent routing algorithms get the fitness equation from torque ripple and speed response so as to give the optimal parameters for better results. Obtained results from the proposed strategy based on metaheuristic methods are compared with the basic case without considering the adjustment of specific parameters. Optimized results found clearly confirmed the ability and the efficiency of the proposed strategy based on metaheuristic methods in improving the performances of the SRM control considering different torque loads.

  3. Scanning slit for HIE-ISOLDE: vibrations test (linear motion actuator from UHV design, MAXON brushless motor, speed = 10 mm/s)

    CERN Document Server

    Bravin, E; Sosa, A

    2014-01-01

    This report summarizes the results of a series of tests performed on the prototype HIE-ISOLDE diagnostic box (HIE-DB) regarding the vibrations and drifts in the transverse position of the scanning blade while moving in and out of beam path in the HIE-ISOLDE short box prototype. To monitor the transverse position of the blade, a series of 0.1 mm diameter holes were drilled on it and their positions were tracked with an optical system. The linear motion actuator was acquired from UHV design (model LSM38-150-SS), and it was adapted to be driven by a brushless EC motor from MAXON. The speed of the scanning blade during the tests was 10 mm/s. The transverse movement of the slit in the direction perpendicular to the movement was lower than 40 m, and is dominated by the displacement of the contact point of the applied force on the lead-screw. An offset on the slit position was observed while changing the direction of movement of the blade, its amplitude being of the order of 30 m. The amplitudes of the displacements...

  4. Note: Reliable and non-contact 6D motion tracking system based on 2D laser scanners for cargo transportation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Keun, E-mail: ykkim@handong.edu [Department of Mechanical and Control Engineering, Handong Global University, Pohang (Korea, Republic of); Kim, Kyung-Soo [Department of Mechanical Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2014-10-15

    Maritime transportation demands an accurate measurement system to track the motion of oscillating container boxes in real time. However, it is a challenge to design a sensor system that can provide both reliable and non-contact methods of 6-DOF motion measurements of a remote object for outdoor applications. In the paper, a sensor system based on two 2D laser scanners is proposed for detecting the relative 6-DOF motion of a crane load in real time. Even without implementing a camera, the proposed system can detect the motion of a remote object using four laser beam points. Because it is a laser-based sensor, the system is expected to be highly robust to sea weather conditions.

  5. Comparison of two methods of tonometry in glaucoma patients: Goldmann applanation tonometer and non-contact tonometer

    Directory of Open Access Journals (Sweden)

    Hong-Feng Li

    2015-01-01

    Full Text Available AIM: To compare the two methods for the measurement of glaucoma patients' intraocular pressure(IOPbetween Goldmann applanation tonometer(GATand non-contact tonometer(NCTand find the laws of the two methods.METHODS: The IOP of 108 glaucoma patients(206 eyeswere measured by GAT and NCT respectively. RESULTS: In 108 glaucoma patients, the average IOP of 206 eyes was 29.77±10.27mmHg by GAT and 24.59±8.58mmHg by NCT. There was significant difference between GAT and NCT(PCONCLUSION: The measurement results with NCT were lower than that of GAT. The higher of IOP, the difference between GAT and NCT was greater. It's better to measure IOP by GAT for the glaucoma patients, in order to avoid the misdiagnosis and mistreatment of glaucoma.

  6. Simulated non-contact atomic force microscopy for GaAs surfaces based on real-space pseudopotentials

    International Nuclear Information System (INIS)

    Kim, Minjung; Chelikowsky, James R.

    2014-01-01

    We simulate non-contact atomic force microscopy (AFM) with a GaAs(1 1 0) surface using a real-space ab initio pseudopotential method. While most ab initio simulations include an explicit model for the AFM tip, our method does not introduce the tip modeling step. This approach results in a considerable reduction of computational work, and also provides complete AFM images, which can be directly compared to experiment. By analyzing tip-surface interaction forces in both our results and previous ab initio simulations, we find that our method provides very similar force profile to the pure Si tip results. We conclude that our method works well for systems in which the tip is not chemically active.

  7. Scleral Buckling Using a Non-contact Wide-Angle Viewing System with a 25-Gauge Chandelier Endoilluminator.

    Science.gov (United States)

    Jo, Jaehyuck; Moon, Byung Gil; Lee, Joo Yong

    2017-12-01

    To report the outcome of scleral buckling using a non-contact wide-angle viewing system with a 25-gauge chandelier endoilluminator. Retrospective analyses of medical records were performed for 17 eyes of 16 patients with primary rhegmatogenous retinal detachment (RRD) without proliferative vitreoretinopathy who had undergone conventional scleral buckling with cryoretinopexy using the combination of a non-contact wide-angle viewing system and chandelier endoillumination. The patients were eight males and five females with a mean age of 26.8 ± 10.2 (range, 11 to 47) years. The mean follow-up period was 7.3 ± 3.1 months. Baseline best-corrected visual acuity was 0.23 ± 0.28 logarithm of the minimum angle of resolution units. Best-corrected visual acuity at the final visit showed improvement (0.20 ± 0.25 logarithm of the minimum angle of resolution units), but the improvement was not statistically significant (p = 0.722). As a surgery-related complication, there was vitreous loss at the end of surgery in one eye. As a postoperative complication, increased intraocular pressure (four cases) and herpes simplex epithelial keratitis (one case) were controlled postoperatively with eye drops. One case of persistent RRD after primary surgery needed additional vitrectomy, and the retina was postoperatively attached. Scleral buckling with chandelier illumination as a surgical technique for RRD has the advantages of relieving the surgeon's neck pain from prolonged use of the indirect ophthalmoscope and sharing the surgical procedure with another surgical team member. In addition, fine retinal breaks that are hard to identify using an indirect ophthalmoscope can be easily found under the microscope by direct endoillumination. © 2017 The Korean Ophthalmological Society

  8. Non-contact respiration monitoring for in-vivo murine micro computed tomography: characterization and imaging applications

    International Nuclear Information System (INIS)

    Burk, Laurel M; Lee, Yueh Z; Wait, J Matthew; Lu Jianping; Zhou, Otto Z

    2012-01-01

    A cone beam micro-CT has previously been utilized along with a pressure-tracking respiration sensor to acquire prospectively gated images of both wild-type mice and various adult murine disease models. While the pressure applied to the abdomen of the subject by this sensor is small and is generally without physiological effect, certain disease models of interest, as well as very young animals, are prone to atelectasis with added pressure, or they generate too weak a respiration signal with this method to achieve optimal prospective gating. In this work we present a new fibre-optic displacement sensor which monitors respiratory motion of a subject without requiring physical contact. The sensor outputs an analogue signal which can be used for prospective respiration gating in micro-CT imaging. The device was characterized and compared against a pneumatic air chamber pressure sensor for the imaging of adult wild-type mice. The resulting images were found to be of similar quality with respect to physiological motion blur; the quality of the respiration signal trace obtained using the non-contact sensor was comparable to that of the pressure sensor and was superior for gating purposes due to its better signal-to-noise ratio. The non-contact sensor was then used to acquire in-vivo micro-CT images of a murine model for congenital diaphragmatic hernia and of 11-day-old mouse pups. In both cases, quality CT images were successfully acquired using this new respiration sensor. Despite the presence of beam hardening artefacts arising from the presence of a fibre-optic cable in the imaging field, we believe this new technique for respiration monitoring and gating presents an opportunity for in-vivo imaging of disease models which were previously considered too delicate for established animal handling methods. (paper)

  9. Automated real-time search and analysis algorithms for a non-contact 3D profiling system

    Science.gov (United States)

    Haynes, Mark; Wu, Chih-Hang John; Beck, B. Terry; Peterman, Robert J.

    2013-04-01

    The purpose of this research is to develop a new means of identifying and extracting geometrical feature statistics from a non-contact precision-measurement 3D profilometer. Autonomous algorithms have been developed to search through large-scale Cartesian point clouds to identify and extract geometrical features. These algorithms are developed with the intent of providing real-time production quality control of cold-rolled steel wires. The steel wires in question are prestressing steel reinforcement wires for concrete members. The geometry of the wire is critical in the performance of the overall concrete structure. For this research a custom 3D non-contact profilometry system has been developed that utilizes laser displacement sensors for submicron resolution surface profiling. Optimizations in the control and sensory system allow for data points to be collected at up to an approximate 400,000 points per second. In order to achieve geometrical feature extraction and tolerancing with this large volume of data, the algorithms employed are optimized for parsing large data quantities. The methods used provide a unique means of maintaining high resolution data of the surface profiles while keeping algorithm running times within practical bounds for industrial application. By a combination of regional sampling, iterative search, spatial filtering, frequency filtering, spatial clustering, and template matching a robust feature identification method has been developed. These algorithms provide an autonomous means of verifying tolerances in geometrical features. The key method of identifying the features is through a combination of downhill simplex and geometrical feature templates. By performing downhill simplex through several procedural programming layers of different search and filtering techniques, very specific geometrical features can be identified within the point cloud and analyzed for proper tolerancing. Being able to perform this quality control in real time

  10. Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

    Science.gov (United States)

    Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

    2007-03-01

    Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

  11. Piezoelectric Motors, an Overview

    OpenAIRE

    Karl Spanner; Burhanettin Koc

    2016-01-01

    Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ult...

  12. The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry.

    Science.gov (United States)

    Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

    2005-07-01

    To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT). CCT was recorded for either eye (randomly selected) of each of 105 untreated patients with ocular hypertension and glaucoma attending the glaucoma research unit at Moorfields Eye Hospital. For each of the selected eyes, IOP was measured with the GAT (two observers), Tono-Pen, OBF, and NCT in a randomised order. The relation of measured IOP and of inter-tonometer differences with CCT and subject age was explored by linear regression analysis. A significant association between measured IOP and CCT was found with each instrument. The change in measured IOP for a 10 mum increase in CCT was 0.28, 0.31, 0.38, and 0.46 for the GAT, Tono-Pen, OBF, and NCT, respectively (all p< or = 0.05). There was a significant association between the NCT/GAT differences and CCT, with a tendency of NCT to overestimate GAT in eyes with thicker corneas. There was a significant association between GAT/Tono-Pen and OBF/Tono-Pen differences and age, with a tendency of GAT and OBF to overestimate the Tono-Pen in eyes of older subjects. IOP measurement by all four methods is affected by CCT. The NCT is affected by CCT significantly more than the GAT. Subject age has a differential effect on the IOP measurements made by the GAT and OBF compared to the Tono-Pen.

  13. [Effects of central corneal thickness and corneal curvature on measurement of intraocular pressure with Goldmann applanation tonometer and non-contact tonometer].

    Science.gov (United States)

    Zhang, Yang; Zhao, Jia-liang; Bian, Ai-ling; Liu, Xiao-li; Jin, Yu-mei

    2009-08-01

    To investigate the effects of central corneal thickness (CCT) and corneal curvature (CC) on intraocular pressure (IOP) measurements by the Goldmann applanation tonometer (GAT) and the non-contact tonometer (NCT). One hundred and twenty patients were recruited from the clinic of Peking Union Medical College Hospital. The CCT was measured by ultrasound pachymetry and the mean radius of CC by using Canon PK-5 refractometer. The IOP of each eye was measured by both GAT and NCT. Linear regression was used to compare the measurements of GAT and NCT; multi regression was used to analyze the relationships between CCT, CC and the measurements of GAT and NCT. Bland-Altman method was used to compare the effect of NCT and GAT on the IOP measurements. The results of the right eyes were reported in this paper. The mean and standard deviation of IOP measured by GAT and NCT was (18.4 + or - 4.0) mm Hg (1 mm Hg = 0.133 kPa) and (17.0 + or - 4.6) mm Hg, respectively, the difference was statistically significant (r = 0.835, P = 0.000). IOP measured using GAT increased by 0.039 mm Hg per microm increase in CCT. IOP measured using NCT increased by 0.064 mm Hg per microm increase in CCT. For an increase of 1 mm of mean corneal curvature there was decrease in IOP of 2.648 mm Hg measured by the GAT and of 3.190 mm Hg measured by the NCT. Compared to the GAT, NCT underestimated at low IOP level and overestimated at higher IOP level. The IOP measurement obtained with both GAT and NCT varied with CCT and CC. CCT affected IOP measurements by NCT more than that by GAT.

  14. Which Extrinsic and Intrinsic Factors are Associated with Non-Contact Injuries in Adult Cricket Fast Bowlers?

    Science.gov (United States)

    Olivier, Benita; Taljaard, Tracy; Burger, Elaine; Brukner, Peter; Orchard, John; Gray, Janine; Botha, Nadine; Stewart, Aimee; Mckinon, Warrick

    2016-01-01

    The high prevalence of injury amongst cricket fast bowlers exposes a great need for research into the risk factors associated with injury. Both extrinsic (environment-related) and intrinsic (person-related) risk factors are likely to be implicated within the high prevalence of non-contact injury amongst fast bowlers in cricket. Identifying and defining the relative importance of these risk factors is necessary in order to optimize injury prevention efforts. The objective of this review was to assess and summarize the scientific literature related to the extrinsic and intrinsic factors associated with non-contact injury inherent to adult cricket fast bowlers. A systematic review was performed in compliance with the PRISMA guidelines. This review considered both experimental and epidemiological study designs. Studies that included male cricket fast bowlers aged 18 years or above, from all levels of play, evaluating the association between extrinsic/intrinsic factors and injury in fast bowlers were considered for inclusion. The three-step search strategy aimed at finding both published and unpublished studies from all languages. The searched databases included MEDLINE via PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Controlled Trials Register in the Cochrane Library, Physiotherapy Evidence Database (PEDro), ProQuest 5000 International, ProQuest Health and Medical Complete, EBSCO MegaFile Premier, Science Direct, SPORTDiscus with Full Text and SCOPUS (prior to 28 April 2015). Initial keywords used were 'cricket', 'pace', 'fast', 'bowler', and 'injury'. Papers which fitted the inclusion criteria were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). A total of 16 studies were determined to be suitable for inclusion in this

  15. Characteristics of corneal biomechanical responses detected by a non-contact scheimpflug-based tonometer in eyes with glaucoma.

    Science.gov (United States)

    Jung, Younhea; Park, Hae-Young L; Yang, Hee Jung; Park, Chan Kee

    2017-11-01

    To determine the corneal biomechanical properties in eyes with glaucoma using a non-contact Scheimpflug-based tonometer. Corneal biomechanical responses were examined using a non-contact Scheimpflug-based tonometer. The tonometer parameters of the normal control group (n = 75) were compared with those of the glaucoma group (n = 136), including an analysis of glaucoma subgroups categorized by visual field loss. After adjusting for potential confounding factors, including the intraocular pressure (IOP), central corneal thickness (CCT), age and axial length, the deformation amplitude was smaller in the glaucoma group (1.09 ± 0.02 mm) than in the normal control group (1.12 ± 0.02 mm; p value = 0.031). The deformation amplitude and the deflection amplitude of the severe glaucoma group (1.12 ± 0.02 mm and 0.92 ± 0.01 mm) were significantly greater than that of the early glaucoma group (1.07 ± 0.01   mm and 0.88 ± 0.11 mm, p = 0.006 and p = 0.031), whereas that of the moderate glaucoma group (1.09 ± 0.02 mm and 0.90 ± 0.02 mm) was greater than that of the early glaucoma group, but this difference was not statistically significant. The deformation amplitude showed a negative correlation with the CCT in the normal control group (r = -0.235), with a weaker negative relationship observed in the early glaucoma group (r = -0.099). However, in the moderate and severe glaucoma groups, the deformation amplitude showed a positive relationship with the CCT, showing an inverse relationship. The duration and number of antiglaucomatous eyedrops used had negative correlations with the CCT in eyes with moderate and severe glaucoma. Overall, the glaucoma group showed significantly less deformable corneas than did the normal controls, even after adjusting for the IOP, CCT, age and axial length. However, there were also differences according to the severity of glaucoma, where the corneal deformation amplitude was greater in the severe glaucoma

  16. COMPARISON OF INTRAOCULAR PRESSURE MEASUREMENT WITH NON-CONTACT TONOMETRY AND APPLANATION TONOMETRY AMONG VARIOUS CENTRAL CORNEAL THICKNESS GROUPS

    Directory of Open Access Journals (Sweden)

    Radhakrishnan B

    2018-02-01

    Full Text Available BACKGROUND Glaucoma is the second leading cause of blindness worldwide. Intraocular Pressure (IOP is the only known modifiable risk factor that has been shown to delay progression in both ocular hypertension and glaucoma patients. Clinical measurement of IOP has undergone several technical advances from the initial digital tension measurements, through indentation tonometry, to applanation tonometry and non-contact tonometry. This study was done to compare the intraocular pressure (IOP measurements with Non Contact Tonometry (NCT and Goldmann Applanation tonometry (GAT and to compare NCT IOP and GAT IOP among various central corneal thickness (CCT groups. MATERIALS AND METHODS IOP measurements were done by NCT and then by GAT followed by CCT. All IOP readings were taken in the sitting position over fifteen minutes. NCT was performed before the GAT to avoid the known mild reduction of IOP by anterior chamber compression with GAT. RESULTS The study included 200 eyes of 100 patients. Mean age of the patients was 58.14 ± 11.7 years (range 35- 81 years. The study population consisted of 58 males and 42 females. The mean ± SD intraocular pressure measurements were 23.39 ± 4.6 mmHg and 22.41 ± 5.9 mmHg for NCT and GAT, respectively. The difference between the NCT and GAT IOP was 0.98 ± 4.7 mm Hg. Mean CCT of the study group was 545.74 ± 38.23 microns. The IOP measured with both GAT and NCT showed no significant change with increasing CCT. The difference between the means increases with increasing CCT upto 600 microns. At lower IOPs ≤ 20 mm Hg, GAT measures are higher than NCT and this relationship is reversed at high IOPs. CONCLUSION Intraocular pressure measurement by NCT was consistently higher than GAT. There was a tendency for NCT to underestimate IOP at lower ranges and overestimates IOP at higher ranges. By applying appropriate correction factor for CCT, Noncontact tonometry could be used as a good screening tool for glaucoma evaluation.

  17. Control de velocidad del motor de indución empleando linealización por realimentación de estados Speed control of induction motor using state feedback linearization

    OpenAIRE

    Eduardo Giraldo Suárez; Santiago Sánchez Acevedo

    2009-01-01

    Este documento presenta la aplicación de la técnica de control no lineal clásica llamada linealización por realimentación de variables de estado. Se hace una aplicación en el motor de inducción, la variable a controlar es la velocidad del eje del motor, el sistema emplea el esquema de control vectorial para máquinas de corriente alterna desarrollado en las últimas décadas; este método es análogo a la técnica de control del motor de corriente directa. El modelo del motor de inducción se descri...

  18. Non-contact multi-frequency magnetic induction spectroscopy system for industrial-scale bio-impedance measurement

    International Nuclear Information System (INIS)

    O'Toole, M D; Marsh, L A; Davidson, J L; Tan, Y M; Armitage, D W; Peyton, A J

    2015-01-01

    Biological tissues have a complex impedance, or bio-impedance, profile which changes with respect to frequency. This is caused by dispersion mechanisms which govern how the electromagnetic field interacts with the tissue at the cellular and molecular level. Measuring the bio-impedance spectra of a biological sample can potentially provide insight into the sample’s properties and its cellular structure. This has obvious applications in the medical, pharmaceutical and food-based industrial domains. However, measuring the bio-impedance spectra non-destructively and in a way which is practical at an industrial scale presents substantial challenges. The low conductivity of the sample requires a highly sensitive instrument, while the demands of industrial-scale operation require a fast high-throughput sensor of rugged design. In this paper, we describe a multi-frequency magnetic induction spectroscopy (MIS) system suitable for industrial-scale, non-contact, spectroscopic bio-impedance measurement over a bandwidth of 156 kHz–2.5 MHz. The system sensitivity and performance are investigated using calibration and known reference samples. It is shown to yield rapid and consistently sensitive results with good long-term stability. The system is then used to obtain conductivity spectra of a number of biological test samples, including yeast suspensions of varying concentration and a range of agricultural produce, such as apples, pears, nectarines, kiwis, potatoes, oranges and tomatoes. (paper)

  19. A Time-Frequency Respiration Tracking System using Non-Contact Bed Sensors with Harmonic Artifact Rejection

    Science.gov (United States)

    Beattie, Zachary T.; Jacobs, Peter G.; Riley, Thomas C.; Hagen, Chad C.

    2015-01-01

    Sleep apnea is a serious health condition that affects many individuals and has been associated with serious health conditions such as cardiovascular disease. Clinical diagnosis of sleep apnea requires that a patient spend the night in a sleep clinic while being wired up to numerous obtrusive sensors. We are developing a system that utilizes respiration rate and breathing amplitude inferred from non-contact bed sensors (i.e. load cells placed under bed supports) to detect sleep apnea. Multi-harmonic artifacts generated either biologically or as a result of the impulse response of the bed have made it challenging to track respiration rate and amplitude with high resolution in time. In this paper, we present an algorithm that can accurately track respiration on a second-by-second basis while removing noise harmonics. The algorithm is tested using data collected from 5 patients during overnight sleep studies. Respiration rate is compared with polysomnography estimations of respiration rate estimated by a technician following clinical standards. Results indicate that certain subjects exhibit a large harmonic component of their breathing signal that can be removed by our algorithm. When compared with technician transcribed respiration rates using polysomnography signals, we demonstrate improved accuracy of respiration rate tracking using harmonic artifact rejection (mean error: 0.18 breaths/minute) over tracking not using harmonic artifact rejection (mean error: −2.74 breaths/minute). PMID:26738176

  20. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

    Directory of Open Access Journals (Sweden)

    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  1. Acquiring a 2D rolled equivalent fingerprint image from a non-contact 3D finger scan

    Science.gov (United States)

    Fatehpuria, Abhishika; Lau, Daniel L.; Hassebrook, Laurence G.

    2006-04-01

    The use of fingerprints as a biometric is both the oldest mode of computer aided personal identification and the most relied-upon technology in use today. But current fingerprint scanning systems have some challenging and peculiar difficulties. Often skin conditions and imperfect acquisition circumstances cause the captured fingerprint image to be far from ideal. Also some of the acquisition techniques can be slow and cumbersome to use and may not provide the complete information required for reliable feature extraction and fingerprint matching. Most of the difficulties arise due to the contact of the fingerprint surface with the sensor platen. To attain a fast-capture, non-contact, fingerprint scanning technology, we are developing a scanning system that employs structured light illumination as a means for acquiring a 3-D scan of the finger with sufficiently high resolution to record ridge-level details. In this paper, we describe the postprocessing steps used for converting the acquired 3-D scan of the subject's finger into a 2-D rolled equivalent image.

  2. IOP measurement in silicone oil tamponade eyes by Corvis ST tonometer, Goldmann applanation tonometry and non-contact tonometry.

    Science.gov (United States)

    Zhang, Yang; Zheng, Lin; Bian, Ailing; Zhou, Qi

    2018-04-01

    To compare the postoperative intraocular pressure (IOP) of eyes following pars plana vitrectomy (PPV) combined with intravitreal silicone oil (SO) tamponade by Corneal Visualization Scheimpflug Technology (CST), Goldmann applanation tonometry (GAT) and non-contact tonometry (NCT). Thirty-eight participants who had undergone PPV combined with SO tamponade to treat vitreoretinal diseases were enrolled. Postoperative IOP measurements were obtained using CST, NCT and GAT. Inter-device agreement was assessed by Bland-Altman analysis. The correlation coefficient was used to describe the potential postoperative factors affecting the postoperative IOP differences between each device. Bland-Altman analysis revealed the bias between CST and GAT, between CST and NCT, and between GAT and NCT to be -0.2, 2.1 and 2.4 mmHg, respectively. CST and GAT correlated well with each other. NCT values were lower than those of GAT and CST (all p contact method for measuring postoperative IOP in SO tamponade eyes.

  3. Intraocular pressure asymmetry is not a clinically-significant feature when using the PULSAIR non-contact tonometer.

    Science.gov (United States)

    Pointer, J S

    1997-11-01

    This report describes the results of a retrospective analysis of intraocular pressure (i.o.p.) values recorded from the right (R) and left (L) eyes of middle-aged and elderly at-risk but assumed non-glaucomatous subjects. The tensions had been measured using the Keeler PULSAIR non-contact tonometer (NCT) in the course of routine optometric practice when individuals attended for a sight test. These bilateral IOP data were collated on the basis of each subject's gender, (male/female), age (40-59 years/60+ years) and the time of the tonometry assessment (a.m./p.m.). Wherever possible material was equi-partitioned across these three bipartite variables producing balanced data groupings. Pair-wise testing of R versus L absolute values of pneumo-applanation pressures across any of the balanced data groupings failed to reveal a statistically-significant difference between the paired IOP distributions. There was a consistent but small relative IOP asymmetry (L > R) in these data. Further analysis indicated that this asymmetry only attained borderline statistical significance with respect to subject's age: neither gender nor the time of assessment were statistically significant features, and there were no statistically-significant interactions between any of the three variables. In conclusion, provided that the manufacturer's operating instructions are adhered to, IOP asymmetry is not a clinically-significant feature when using the PULSAIR NCT on a clinical population at risk of developing glaucoma.

  4. Deterioration in the accuracy of the pulsair non-contact tonometer with use: need for regular calibration.

    Science.gov (United States)

    Atkinson, P L; Wishart, P K; James, J N; Vernon, S A; Reid, F

    1992-01-01

    The Pulsair non-contact tonometer (Keeler Pulsair: Keeler UK) has been shown to be a versatile instrument particularly suitable for screening for raised intraocular pressure. Although demonstrated to be accurate initially when compared to the Goldmann applanation tonometer no study has examined its long-term accuracy. Comparisons of three Pulsair tonometers with different degrees of usage with the Goldmann tonometer are described. Measurements were obtained from 64, 116, and 223 eyes in three separate comparative studies. Correlation coefficients of between 0.78 and 0.90 were obtained, the least used instrument being significantly more accurate than the two more extensively used instruments. Taking the Goldmann tonometer as the standard tonometer, and the aim to detect intraocular pressures of greater than 21 mmHg, sensitivities of 40%, 48%, and 85% for the three Pulsair tonometers respectively were shown. The Pulsair tonometer appears liable to a long-term drift in accuracy with use, and we suggest that provision is made for the regular re-calibration of the instrument.

  5. [The American Optical non-contact tonometer and its results compared with the Goldmann applanation tonometer (author's transl)].

    Science.gov (United States)

    Derka, H

    1980-11-01

    Intraocular pressure (IOP) of 617 eyes was measured with both an AO non-contact tonometer (NCT) and a Goldmann applanation tonometer (GAT). - Statistical evaluation and the scattergram gave the following results: Correlation coefficient r = 0.74. Regression line y = 3.01 + 0.8x. Close agreement between mean GAT (17.8 mmHg) and mean NCT (17.3 mmHg). Variations in readings for NCT-GAT in 92% of all cases with a range of +/- 8 mmHg (95% reliability range) - in some cases much higher or lower - for all IOP values between 10 and 30 mmHg. - Ten NCT measurements were carried out on 42 eyes. The mean values lay between 9 and 22 mmHg, with deviations of up to +/- 6 mmHg from the GAT values. The range was 3 to 13 mmHg, averaging 7.1 mmHg. Standard deviations observed from these measurements were 1.03 minimum, 2.29 average and 3.99 maximum. These were not correlated to IOP. - Changes in the place of applanation are discussed as a possible cause of the variability of NCT readings.

  6. Non-contact measurement of tremor for the characterisation of Parkinsonian individuals: comparison between Kinect and Laser Doppler vibrometer

    Science.gov (United States)

    Casacanditella, L.; Cosoli, G.; Ceravolo, MG; Tomasini, EP

    2017-08-01

    Parkinson’s disease is a progressive neurodegenerative disorder affecting the central nervous system. One of its main and most evident symptoms is the tremor, which usually manifests at rest with varying intensity during time. An important diagnostic challenge is the differential diagnosis between Parkinson’s disease and the other most widely represented tremor syndrome, i.e. Essential (or senile) tremor. At present there are no standard methods for the quantification of tremor and the diagnosis of both Parkinson’s disease and Essential tremor is mainly done on the base of clinical criteria and by using rating scales. The aim of this work is to objectively and non-invasively assess the tremor linked to the quoted diseases, using non-contact techniques: Laser Doppler Vibrometer (LDV) and Kinect for Windows device. Two subjects with Parkinson’s disease and one with Essential tremor were tested in different conditions: at rest, during a cognitive task, with forward stretched arms and in “Wing position”. The results from data processing in terms of tremor frequency seem to be comparable, with a mean deviation of 0.31 Hz. Furthermore, the values computed are consistent with what is stated in the literature (i.e. 4-12 Hz). So, both LDV and Kinect device can be considered suitable to be used as an objective means for the assessment and monitoring of Parkinson’s disease tremor, helping the clinician in the choice of the most suitable treatment for the patients.

  7. Millimeter-wave emissivity as a metric for the non-contact diagnosis of human skin conditions.

    Science.gov (United States)

    Owda, Amani Yousef; Salmon, Neil; Harmer, Stuart William; Shylo, Sergiy; Bowring, Nicholas John; Rezgui, Nacer Ddine; Shah, Mamta

    2017-10-01

    A half-space electromagnetic model of human skin over the band 30-300 GHz was constructed and used to model radiometric emissivity. The model showed that the radiometric emissivity rose from 0.4 to 0.8 over this band, with emission being localized to a layer approximately one millimeter deep in the skin. Simulations of skin with differing water contents associated with psoriasis, eczema, malignancy, and thermal burn wounds indicated radiometry could be used as a non-contact technique to detect and monitor these conditions. The skin emissivity of a sample of 30 healthy volunteers, measured using a 95 GHz radiometer, was found to range from 0.2 to 0.7, and the experimental measurement uncertainty was ±0.002. Men on average were found to have an emissivity 0.046 higher than those of women, a measurement consistent with men having thicker skin than women. The regions of outer wrist and dorsal forearm, where skin is thicker, had emissivities 0.06-0.08 higher than the inner wrist and volar forearms where skin is generally thinner. Recommendations are made to develop a more sophisticated model of the skin and to collect larger data sets to obtain a deeper understanding of the signatures of human skin in the millimeter wave band. Bioelectromagnetics. 38:559-569, 2017. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

  8. 3D Blade Vibration Measurements on an 80 m Diameter Wind Turbine by Using Non-contact Remote Measurement Systems

    Science.gov (United States)

    Ozbek, Muammer; Rixen, Daniel J.

    Non-contact optical measurement systems photogrammetry and laser interferometry are introduced as cost efficient alternatives to the conventional wind turbine/farm monitoring systems that are currently in use. The proposed techniques are proven to provide an accurate measurement of the dynamic behavior of a 2.5 MW—80 m diameter—wind turbine. Several measurements are taken on the test turbine by using 4 CCD cameras and 1 laser vibrometer and the response of the turbine is monitored from a distance of 220 m. The results of the infield tests and the corresponding analyses show that photogrammetry (also can be called as videogrammetry or computer vision technique) enable the 3D deformations of the rotor to be measured at 33 different points simultaneously with an average accuracy of ±25 mm, while the turbine is rotating. Several important turbine modes can also be extracted from the recorded data. Similarly, laser interferometry (used for the parked turbine only) provides very valuable information on the dynamic properties of the turbine structure. Twelve different turbine modes can be identified from the obtained response data.

  9. An ultra-bright white LED based non-contact skin cancer imaging system with polarization control

    Science.gov (United States)

    Günther, A.; Basu, C.; Roth, B.; Meinhardt-Wollweber, M.

    2013-06-01

    Early detection and excision of melanoma skin cancer is crucial for a successful therapy. Dermoscopy in direct contact with the skin is routinely used for inspection, but screening is time consuming for high-risk patients with a large number of nevi. Features like symmetry, border, color and most importantly changes like growth or depigmentation of a nevus may indicate malignancy. We present a non-contact remote imaging system for human melanocytic nevi with homogenous illumination by an ultra-bright white LED. The advantage compared to established dermoscopy systems requiring direct skin contact is that deformation of raised nevi is avoided and full-body scans of the patients may time-efficiently be obtained while they are in a lying, comfortable position. This will ultimately allow for automated screening in the future. In addition, calibration of true color rendering, which is essential for distinguishing between benign and malignant lesions and to ensure reproducibility and comparison between individual check-ups in order to follow nevi evolution is implemented as well as suppression of specular highlights on the skin surface by integration of polarizing filters. Important features of the system which will be crucial for future integration into automated systems are the possibility to record images without artifacts in combination with short exposure times which both reduce image blurring caused by patient motion.

  10. Study of non-contact measurement of the thermal expansion coefficients of materials based on laser feedback interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Fasong [The State Key Lab of Precision Measurement Technology and Instrument, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Departments of Physics, College of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Tan, Yidong; Zhang, Shulian, E-mail: zsl-dpi@mail.tsinghua.edu.cn [The State Key Lab of Precision Measurement Technology and Instrument, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Lin, Jing; Ding, Yingchun [Departments of Physics, College of Science, Beijing University of Chemical Technology, Beijing 100029 (China)

    2015-04-15

    The noncooperative and ultrahigh sensitive length measurement approach is of great significance to the study of a high-precision thermal expansion coefficient (TEC) determination of materials at a wide temperature range. The novel approach is presented in this paper based on the Nd:YAG microchip laser feedback interferometry with 1064 nm wavelength, the beam frequency of which is shifted by a pair of acousto-optic modulators and then the heterodyne phase measurement technique is used. The sample is placed in a muffle furnace with two coaxial holes opened on the opposite furnace walls. The measurement beams are perpendicular and coaxial on each surface of the sample, the configuration which can not only achieve the length measurement of sample but also eliminate the influence of the distortion of the sample supporter. The reference beams inject on the reference mirrors which are put as possible as near the holes, respectively, to eliminate the air disturbances and the influence of thermal lens effect out of the furnace chamber. For validation, the thermal expansion coefficients of aluminum and steel 45 samples are measured from room temperature to 748 K, which proved measurement repeatability of TECs is better than 0.6 × 10{sup −6}(K{sup −1}) at the range of 298 K–598 K and the high-sensitive non-contact measurement of the low reflectivity surface induced by the oxidization of the samples at the range of 598 K–748 K.

  11. [Study of cytogenetic and cytotoxic effect of non-contact electrochemically-activated waters in the five organs of rats].

    Science.gov (United States)

    Sycheva, L P; Mikhaĭlova, R I; Beliaeva, N N; Zhurkov, V S; Iurchenko, V V; Savostikova, O N; Alekseeva, A V; Kribtsova, E K; Kovalenko, M A; Akhal'tseva, L V; Sheremet'eva, S M; Iurtseva, N A; Murav'eva, L V; Kamenetskaia, D B

    2014-01-01

    For the first time the multiorgan karyological analysis of five organs of rats was applied for the study of the cytogenetic and cytotoxic action of the four types of non-contact electrochemically activated water in the 30-days in vivo experiment. The effects of investigated waters were not detected in bone marrow polychromatic erythrocytes. "Anolyte" (ORP = -362 mV) did not have a negative effect on rats. "Catholyte-5" (ORP = +22 mV) and "Catholyte-25" (ORP = -60 mV) induced cytogenetic abnormalities in the bladder and fore stomach. The same catholytes and "Catholyte-40" (ORP = -10 mV) changed the proliferation indices: increased the mitotic index in the fore stomach epithelium and reduced the frequency of binucleated cells in the fore stomach, bladder and lungs. The increase in the rate of cells with cytogenetic abnormalities on the background of the promotion of mitotic activity can be considered as a manifestation of the negative effect, typical for catolytes, but the effect of each out of them has its own features.

  12. Non-contact acquisition of respiration and heart rates using Doppler radar with time domain peak-detection algorithm.

    Science.gov (United States)

    Xiaofeng Yang; Guanghao Sun; Ishibashi, Koichiro

    2017-07-01

    The non-contact measurement of the respiration rate (RR) and heart rate (HR) using a Doppler radar has attracted more attention in the field of home healthcare monitoring, due to the extremely low burden on patients, unconsciousness and unconstraint. Most of the previous studies have performed the frequency-domain analysis of radar signals to detect the respiration and heartbeat frequency. However, these procedures required long period time (approximately 30 s) windows to obtain a high-resolution spectrum. In this study, we propose a time-domain peak detection algorithm for the fast acquisition of the RR and HR within a breathing cycle (approximately 5 s), including inhalation and exhalation. Signal pre-processing using an analog band-pass filter (BPF) that extracts respiration and heartbeat signals was performed. Thereafter, the HR and RR were calculated using a peak position detection method, which was carried out via LABVIEW. To evaluate the measurement accuracy, we measured the HR and RR of seven subjects in the laboratory. As a reference of HR and RR, the persons wore contact sensors i.e., an electrocardiograph (ECG) and a respiration band. The time domain peak-detection algorithm, based on the Doppler radar, exhibited a significant correlation coefficient of HR of 0.92 and a correlation coefficient of RR of 0.99, between the ECG and respiration band, respectively.

  13. Non-contact procedure to measure heart and lung activities in preterm pediatric patients with skin disorders

    Science.gov (United States)

    Marchionni, P.; Scalise, L.; Antognoli, L.; Nobile, S.; Carnielli, V. P.

    2018-04-01

    Preterm patients can have an higher risk of fatalities and can be subjected to long-term disability. With many organs still in the phase of development, the earlier the delivery, the higher the risk and they are therefore hospitalized in specialized neonatal intensive care units) where heart rate and lungs activity are continuously assessed. These are mostly monitored by set of electrodes placed in contact with skin (two in thorax area and one in abdominal area). This paper address the problem of preterm cardiac and respiratory monitoring in a patient with severe skin disorders who can not monitored with standard electrodes because of his dry, thickened, scaly skin. As a solution, we propose a fully non-contact measurement method, based on laser Doppler vibrometry, able to continuously record the movements of wall-chest and extract from this signal, the heart rate and the respiratory activity of the patient. The results show a good agreement between the standard contact measurement methods and the proposed one (no statistical difference between data) with a data uncertainty of 2.9% for the heart rate data and of 9.5% for the respiration rate (k=2), in line with the classical measurement methods.

  14. A comparison of the Goldmann applanation and non-contact (Keeler Pulsair EasyEye) tonometers and the effect of central corneal thickness in indigenous African eyes.

    Science.gov (United States)

    Babalola, O E; Kehinde, A V; Iloegbunam, A C; Akinbinu, T; Moghalu, C; Onuoha, I

    2009-03-01

    The Keeler Pulsair EasyEye non-contact tonometer (NCT) was introduced into practice at Rachel Eye Center Abuja, Nigeria, where the patients are indigenous Africans. This was compared to the 'gold standard' Goldmann applanation tonometer (GAT) to determine if the instrument was accurate in Africans, with particular reference to the influence of central corneal thickness (CCT). 174 eyes of 88 patients were analysed. Pachymetry was performed using Sonomed PacScan AP300, and GAT with the Haag Streit R-900. Pachymetric corrections of NCT (NCTc) and GAT (GATc) were carried out with the Sonomed algorithm. Pearson's correlation r, linear regression analysis, Student t-test and Bland-Altman analysis were used to compare the instruments. Mean NCT readings were similar (17.36 mmHg) to mean GAT (17.42 mmHg; p = 0.769). GAT/NCT correlation coefficient, r, was 0.883 as compared with 0.868 for GATc/NCTc. The linear regression equation was GAT = 2.79 + 0.84*NCT (r(2) = 0.78). Forty-five per cent of differences were within 1 mmHg, while 79% were within 3 mmHg. This was similar to findings in some studies on Caucasians. Bland-Altman analysis however suggested that the spread of differences was wider than in those studies. Outliers (differences more than 5 mmHg) sometimes reflected difficulties encountered with GAT in routine practice. Mean CCT was 537.9 microm, (S.D. 38.4, 95% confidence interval 532.1-543.7 microm) and CCT appeared lower than in Caucasians. Both GAT and NCT IOP tended to rise with increasing CCT but NCT had a greater tendency to do so. Regression analysis suggested that NCT IOP increased by 0.6 mmHg for every 10 mum increase in CCT, compared to 0.4 mmHg for GAT. Thirty-eight per cent of the patients preferred NCT as opposed to 25% GAT. The Keeler Pulsair EasyEye gives reliable measurements of IOP in African eyes but is significantly affected by CCT. Particularly in borderline cases where management decisions have to be taken, it may be necessary to have pachymetric

  15. Association between maximal hamstring muscle strength and hamstring muscle pre-activity during a movement associated with non-contact ACL injury

    DEFF Research Database (Denmark)

    Zebis, M. K.; Sorensen, R. S.; Thorborg, K.

    2015-01-01

    Background: Reduced hamstring pre-activity during sidecutting increases the risk for non-contact ACL injury. During the last decade resistance training of the lower limb muscles has become an integral part ofACLinjury prevention in e.g. soccer and handball. However, it is not known whether a stro...

  16. Development of a baby friendly non-contact method for measuring vital signs: First results of clinical measurements in an open incubator at a neonatal intensive care unit

    Science.gov (United States)

    Klaessens, John H.; van den Born, Marlies; van der Veen, Albert; Sikkens-van de Kraats, Janine; van den Dungen, Frank A.; Verdaasdonk, Rudolf M.

    2014-02-01

    For infants and neonates in an incubator vital signs, such as heart rate, breathing, skin temperature and blood oxygen saturation are measured by sensors and electrodes sticking to the skin. This can damage the vulnerable skin of neonates and cause infections. In addition, the wires interfere with the care and hinder the parents in holding and touching the baby. These problems initiated the search for baby friendly 'non-contact' measurement of vital signs. Using a sensitive color video camera and specially developed software, the heart rate was derived from subtle repetitive color changes. Potentially also respiration and oxygen saturation could be obtained. A thermal camera was used to monitor the temperature distribution of the whole body and detect small temperature variations around the nose revealing the respiration rate. After testing in the laboratory, seven babies were monitored (with parental consent) in the neonatal intensive care unit (NICU) simultaneously with the regular monitoring equipment. From the color video recordings accurate heart rates could be derived and the thermal images provided accurate respiration rates. To correct for the movements of the baby, tracking software could be applied. At present, the image processing was performed off-line. Using narrow band light sources also non-contact blood oxygen saturation could be measured. Non-contact monitoring of vital signs has proven to be feasible and can be developed into a real time system. Besides the application on the NICU non-contact vital function monitoring has large potential for other patient groups.

  17. Improvement in abdominal and flank contouring by a novel adipocyte-selective non-contact radiofrequency device.

    Science.gov (United States)

    Choi, Sun Young; Kim, Young Jae; Kim, So Yeon; Lee, Woo Jin; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Won, Chonghyun

    2018-05-07

    The demand for undergoing subcutaneous fat reduction has been gradually increasing, and there are many methods and devices for performing non-surgical and non-invasive fat reduction, such as high-intensity focused ultrasound, cryolipolysis, radiofrequency (RF) devices, and lasers. This study evaluated the efficacy and safety of a novel adipocyte-selective non-contact RF device for improving abdominal contouring in Asian subjects. Twenty-four Asian subjects with abundant subcutaneous abdominal and love handle fat tissues were enrolled in this prospective clinical study. They received six 45-min weekly treatments with an RF field device over the abdominal and love handle regions. The body mass index and abdominal circumference were measured at baseline and at 4 and 8 weeks post the last treatment. The thickness of the abdomen and depth of subcutaneous abdominal fat tissue were respectively assessed using calipers and abdominal ultrasonography. A subset of 15 subjects was selected by randomization for fat volume measurement via abdominal CT. For safety evaluation, serum lipid, and liver-related blood tests were performed at baseline and at the sixth treatment session. Subjects rated their heat perception level using a four point scale and their pain score using an 11-point visual analog scale during RF treatment. Twenty-four subjects (21 females and 3 males) completed this study with an 8-week follow-up. The average decreases in abdominal circumference at 4 and 8 weeks post treatment were 3.48 ± 2.11 cm (P < 0.001) and 5.12 ± 0.47 cm (P < 0.001), respectively. The average decreases in abdominal fat thickness at 4 and 8 weeks treatment were 0.27 ± 0.61 cm (P = 0.041) and 0.47 ± 0.60 cm (P = 0.001), respectively. The average decreases in subcutaneous fat tissue depth at 4 and 8 weeks post treatment were 0.16 ± 0.43 cm (P = 0.091) and 0.34 ± 0.39 cm (P < 0.001), respectively. However, there was no

  18. Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

    Science.gov (United States)

    Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Jr., Robert R.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken

    2004-01-01

    Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

  19. Non-contact video-based vital sign monitoring using ambient light and auto-regressive models

    International Nuclear Information System (INIS)

    Tarassenko, L; Villarroel, M; Guazzi, A; Jorge, J; Clifton, D A; Pugh, C

    2014-01-01

    Remote sensing of the reflectance photoplethysmogram using a video camera typically positioned 1 m away from the patient’s face is a promising method for monitoring the vital signs of patients without attaching any electrodes or sensors to them. Most of the papers in the literature on non-contact vital sign monitoring report results on human volunteers in controlled environments. We have been able to obtain estimates of heart rate and respiratory rate and preliminary results on changes in oxygen saturation from double-monitored patients undergoing haemodialysis in the Oxford Kidney Unit. To achieve this, we have devised a novel method of cancelling out aliased frequency components caused by artificial light flicker, using auto-regressive (AR) modelling and pole cancellation. Secondly, we have been able to construct accurate maps of the spatial distribution of heart rate and respiratory rate information from the coefficients of the AR model. In stable sections with minimal patient motion, the mean absolute error between the camera-derived estimate of heart rate and the reference value from a pulse oximeter is similar to the mean absolute error between two pulse oximeter measurements at different sites (finger and earlobe). The activities of daily living affect the respiratory rate, but the camera-derived estimates of this parameter are at least as accurate as those derived from a thoracic expansion sensor (chest belt). During a period of obstructive sleep apnoea, we tracked changes in oxygen saturation using the ratio of normalized reflectance changes in two colour channels (red and blue), but this required calibration against the reference data from a pulse oximeter. (paper)

  20. Measurement of Creep Properties of Ultra-High-Temperature Materials by a Novel Non-Contact Technique

    Science.gov (United States)

    Hyers, Robert W.; Lee, Jonghyun; Rogers, Jan R.; Liaw, Peter K.

    2007-01-01

    A non-contact technique for measuring the creep properties of materials has been developed and validated as part of a collaboration among the University of Massachusetts, NASA Marshall Space Flight Center Electrostatic Levitation Facility (ESL), and the University of Tennessee. This novel method has several advantages over conventional creep testing. The sample is deformed by the centripetal acceleration from the rapid rotation, and the deformed shapes are analyzed to determine the strain. Since there is no contact with grips, there is no theoretical maximum temperature and no concern about chemical compatibility. Materials may be tested at the service temperature even for extreme environments such as rocket nozzles, or above the service temperature for accelerated testing of materials for applications such as jet engines or turbopumps for liquid-fueled engines. The creep measurements have been demonstrated to 2400 C with niobium, while the test facility, the NASA MSFC ESL, has processed materials up to 3400 C. Furthermore, the ESL creep method employs a distribution of stress to determine the stress exponent from a single test, versus the many tests required by conventional methods. Determination of the stress exponent from the ESL creep tests requires very precise measurement of the surface shape of the deformed sample for comparison to deformations predicted by finite element models for different stress exponents. An error analysis shows that the stress exponent can be determined to about 1% accuracy with the current methods and apparatus. The creep properties of single-crystal niobium at 1985 C showed excellent agreement with conventional tests performed according to ASTM Standard E-139. Tests on other metals, ceramics, and composites relevant to rocket propulsion and turbine engines are underway.