MRI-Compatible Grasping Force Sensor With an Inclined Double Parallel Structure Using Fiber Optics

2012 ◽  
Author(s):  
Jumpei Arata ◽  
Shogo Terakawa ◽  
Hideo Fujimoto ◽  
James Sulzer ◽  
Roger Gassert
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Electromagnetic Interference ◽  
Light Transmission ◽  
Precision Grip ◽  
Force Sensor ◽  
Human Motion ◽  
Parallel Structure ◽  
Sensor Structure ◽  
Grasping Force

Investigations of human motor control using functional magnetic resonance imaging (fMRI) are increasingly receiving attention, with applications in fields such as motor learning and rehabilitation. In these neuroscience studies, force and position sensors are used to control haptic devices and safely interact with the human motion in an MR environment. However, conventional force sensors such as strain gauges are known to cause electromagnetic interference originating from electrical cables, transducers, and electronics. Light transmission through optical fibers is one alternative that avoids these problems. Since optical fibers do not produce electromagnetic noise, they can be used in an MR environment without electromagnetic interference. In this paper, we propose a novel design of an MRI-compatible grasping force sensor based on these principles. The sensor structure was designed to fit into an MRI scanner with its inclined double parallel mechanism, and was specifically adapted to precision grip tasks. This paper presents the sensor design and preliminary characterization in a non-MR environment.

scholarly journals MRI-Compatible Grasping Force Sensor with an Inclined Double Parallel Structure using Fiber Optics

2013 ◽  
Vol 26 (3) ◽  
pp. 110-116 ◽  
Author(s):  
Jumpei Arata ◽  
Shogo Terakawa ◽  
James Sulzer ◽  
Roger Gassert ◽  
Hideo Fujimoto
Keyword(s):  
Fiber Optics ◽  
Force Sensor ◽  
Parallel Structure ◽  
Grasping Force

High Sensitive Force Sensing Based on the Optical Fiber Coupling Loss

2013 ◽  
Vol 7 (1) ◽  
Author(s):  
Roozbeh Ahmadi ◽  
Muthukumaran Packirisamy ◽  
Javad Dargahi
Keyword(s):  
Optical Fibers ◽  
Light Transmission ◽  
Force Sensor ◽  
Measurement Range ◽  
Optical Force ◽  
Test Results ◽  
Length Width ◽  
Force Range ◽  
Minimally Invasive Robotic Surgery ◽  
Dynamic Loading Conditions

In the present paper, an innovative miniaturized optical force sensor is introduced for use in medical devices such as minimally invasive robotic-surgery instruments. The sensing principle of the sensor relies on light transmission in optical fibers. Although the sensor is designed for use in surgical systems, it can be used in various other applications due to its novel features. The novelty of the sensor lies in offering four features in a single miniaturized package using a simple optical-based sensing principle. These four features are the high accuracy/resolution, the magnetic resonance compatibility, the electrical passivity, and the absence of drift in the measurement of continuous static force. The proposed sensor was micromachined using microsystems technology and tested. The sensor measures 18 mm, 4 mm, and 1 mm in length, width, and thickness, respectively. The sensor was calibrated and its performance under both static and dynamic loading conditions was investigated. The experimental test results demonstrate a 0.00–2.00 N force range with an rms error of approximately 2% of the force range. Its resolution is 0.02 N. The characteristics of the sensor such as its size, its measurement range, and its sensitivity are also easily tunable.

High-voltage monitoring by the fiber-optic recirculating measuring system

2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov
Keyword(s):  
Optical Fibers ◽  
High Voltage ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Electric Power Industry ◽  
Measuring System ◽  
Voltage Range ◽  
External Electromagnetic Fields ◽  
Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

scholarly journals Shaping Beam Profiles Using Plastic Optical Fiber Tapers with Application to Ice Sensors

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2503
Author(s):  
Kostas Amoiropoulos ◽  
Georgia Kioselaki ◽  
Nikolaos Kourkoumelis ◽  
Aris Ikiades
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Laser Cooling ◽  
Detection Efficiency ◽  
Numerical Aperture ◽  
Beam Profile ◽  
Hollow Beam ◽  
Enhanced Sensitivity ◽  
Surface Irregularities ◽  
Plastic Optical Fibers

Using either bulk or fiber optics the profile of laser beams can be altered from Gaussian to top-hat or hollow beams allowing enhanced performance in applications like laser cooling, optical trapping, and fiber sensing. Here, we report a method based on multimode Plastic Optical Fibers (POF) long-tapers, to tweak the beam profile from near Gaussian to a hollow beam, by generating surface irregularities on the conical sections of the taper with a heat-and-pull technique. Furthermore, a cutback technique applied on long tapers expanded the output beam profile by more than twice the numerical aperture (NA) of the fiber. The enhanced sensitivity and detection efficiency of the extended profile was tested on a fiber optical ice sensor related to aviation safety.

scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2528 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes, in addition to immunity to electromagnetic interference and chemical corrosions. Thus, the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within (−6°, 4°), and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

Fingertip Force Measurement of GloveMAP by Using a Flexi Force Sensor

2015 ◽  
Vol 780 ◽  
pp. 1-5
Author(s):  
Khairunizam Wan ◽  
H.E. Nabilah ◽  
Nor Farahiya ◽  
M. Hazwan Ali ◽  
Rashidah Suhaimi ◽  
...  
Keyword(s):  
Force Measurement ◽  
Current Trend ◽  
Force Sensor ◽  
Force Sensors ◽  
Gaussian Filter ◽  
Natural Interaction ◽  
Fingertip Force ◽  
Grasping Force ◽  
Interface Devices ◽  
A Current

Modernization of human technologies overtime results the need of more freedom technology likes the use of natural interaction to replace a current trend interface devices such as joysticks, mice, keyboards and other related output devices. Dataglove is one of the interface devices that could serve a natural interaction between user and computers. In this paper, a dataglove called GloveMAP is introduced which has the capability of measuring fingertip force. The flexible force sensors are attached to the fingers location of the glove. Several object grasping experiments are conducted and the grasping force signals are measured. A Gaussian filter is introduced to smoothen the acquired force signals.

scholarly journals High-Sensitivity Fiber-Optic Ultrasound Sensors for Medical Imaging Applications

1998 ◽  
Vol 20 (2) ◽  
pp. 103-112 ◽  
Author(s):  
H. Wen ◽  
D.G. Wiesler ◽  
A. Tveten ◽  
B. Danver ◽  
A. Dandridge
Keyword(s):  
Medical Imaging ◽  
Optical Fibers ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
High Sensitivity ◽  
Single Mode ◽  
Piezoelectric Sensors ◽  
Single Element ◽  
Bending Radius ◽  
Laser Interferometers

This paper presents several designs of high-sensitivity, compact fiber-optic ultrasound sensors that may be used for medical imaging applications. These sensors translate ultrasonic pulses into strains in single-mode optical fibers, which are measured with fiber-based laser interferometers at high precision. The sensors are simpler and less expensive to make than piezoelectric sensors, and are not susceptible to electromagnetic interference. It is possible to make focal sensors with these designs, and several schemes are discussed. Because of the minimum bending radius of optical fibers, the designs are suitable for single element sensors rather than for arrays.

Measuring floating ice thickness with optical fibers and DAS, a test case study on a frozen moutain lake.

2021 ◽  
Author(s):  
Olivier Coutant ◽  
Ludovic Moreau ◽  
Pierre Boué ◽  
Eric Larose ◽  
Arnaud Cimolino
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Ambient Noise ◽  
Seismic Waves ◽  
Safety Issue ◽  
Seismic Survey ◽  
Ice Thickness ◽  
Test Case ◽  
Monitoring Method

<p>Accurate monitoring of floating ice thickness is an important safety issue for northern countries where lakes, fjords, and coasts are covered with ice in winter, and used by people to travel. For example in Finland, 15-20 fatal accidents occur every year due to ice-related drowning. We have explored the potential of fiber optics to measure the propagation of seismic waves guided in the ice layer, in order to infer its thickness via the inversion of the dispersion curves. An optical fiber was deployed on a frozen lake at Lacs Roberts (2400m) above Grenoble and we measured with a DAS the signal generated by active sources (hammer) and ambient noise. We demonstrate that we can retrieve the ice thickness. This monitoring method could be of interest since the deployment of a fiber on ice is quite simple (e.g. using a drone) compared to other techniques for ice thickness estimation such as seismic survey or manual drilling.</p>

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