A New Inductive Proximity Sensor Based Guiding Tool to Locate Metal Shrapnel During Surgery
27 Jun 2014-IEEE Transactions on Instrumentation and Measurement (IEEE)-Vol. 63, Iss: 12, pp 2940-2949
TL;DR: An online tool that can help the surgeon in finding the location of the shrapnel during the surgery will be very effective and a prototype of such a tool has been realized using an inductive proximity sensor (IPS).
Abstract: Shrapnel injury is a major cause of death in victims of bomb blast, land mines, and gun fire. Currently, doctors rely on imaging systems to locate the shrapnel before surgery. But, since these images do not provide any real-time information of the location of the shrapnel, effectiveness of surgery solely depends on the doctors' skill to trace them. Therefore, in some cases, the shrapnel, in spite of being visible in the images, may become untraceable during surgery. Hence, an online tool that can help the surgeon in finding the location of the shrapnel during the surgery will be very effective. A prototype of such a tool has been realized using an inductive proximity sensor (IPS). The new IPS is small enough for inserting into the victim's body. Since the detection depth (DD) of an IPS decreases with its diameter, this IPS uses a differential sensing scheme for detection. Hence, the new sensor achieves DDs longer than its diameter. The design of the sensor takes care of the effects of parasitic parameters that become predominant as the size gets smaller and ensures repeatable results. The tool also features a special excitation scheme that has multiple advantages when compared with existing schemes. The details of the sensor, its excitation and performance against different targets under various conditions are presented in this paper.
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TL;DR: Verification results demonstrate that the differential structured IPS realizes the numerical decoupling calculation of the vector impedance of the sensing coil by using 61 look-up table units, and has evident comparative advantages compared with similar measuring techniques.
Abstract: The inductive proximity sensor (IPS) is applicable to displacement measurements in the aviation field due to its non-mechanical contact, safety, and durability. IPS can increase reliability of position detection and decrease maintenance cost of the system effectively in aircraft applications. Nevertheless, the specialty in the aviation field proposes many restrictions and requirements on the application of IPS, including the temperature drift effect of the resistance component of the IPS sensing coil. Moreover, reliability requirements of aircrafts restrict the use of computational-intensive algorithms and avoid the use of process control components. Furthermore, the environment of airborne electronic equipment restricts measurements driven by large current and proposes strict requirements on emission tests of radio frequency (RF) energy. For these reasons, a differential structured IPS measurement method is proposed in this paper. This measurement method inherits the numerical separation of the resistance and inductance components of the IPS sensing coil to improve the temperature adaptation of the IPS. The computational complexity is decreased by combining the dimension-reduced look-up table method to prevent the use of process control components. The proposed differential structured IPS is equipped with a differential structure of distant and nearby sensing coils to increase the detection accuracy. The small electric current pulse excitation decreases the RF energy emission. Verification results demonstrate that the differential structured IPS realizes the numerical decoupling calculation of the vector impedance of the sensing coil by using 61 look-up table units. The measuring sensitivity increased from 135.5 least significant bits (LSB)/0.10 mm of a single-sensing-coil structured IPS to 1201.4 LSB/0.10 mm, and the linear approximation distance error decreased from 99.376 μm to -3.240 μm. The proposed differential structured IPS method has evident comparative advantages compared with similar measuring techniques.
16 citations
Cites background from "A New Inductive Proximity Sensor Ba..."
...Operation control processes from manufacturing [1,2], to chemical metallurgy [3], electric vehicles [4,5], biological medicine [6,7], and aerospace [8,9] require the detection of the position of mechanical moving components....
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TL;DR: A new probe topology is presented here, which has much longer sensing range than existing probes and the design, performance, and the details of a new circuit that minimizes the temperature drift and hysteresis effects of the GMR sensor in the probe simultaneously are presented in this paper.
Abstract: A common approach to detect a metal’s proximity or analyze some characteristic of it in applications, such as proximity sensing, non-destructive evaluation, and so on, is to generate eddy currents in it and then extract the desired information from the features of these eddy currents using eddy current sensors (ECSs). Some of the common ECS are Hall-effect sensors and inductive coils. Lately, giant magnetoresistive (GMR) sensors are also used for ECS due to their higher sensitivity and better low-frequency response. Due to these features, a new application has been identified for GMR-based ECS probes, which is real-time detection of metal shrapnel in human body during surgery. Since metal shrapnel cause grievous injuries to victims of bomb blasts, land mines, and so on, and the imaging modalities that doctors use presently to locate them do not provide any real-time information of their location during surgery, this probe will provide immense help to the doctors for tracing these shrapnel during surgery. However, existing GMR-based probes have limited sensing range, and therefore, they are not suitable for this application. Hence, a new probe topology is presented here, which has much longer sensing range than existing probes. The design of this probe, its performance, and the details of a new circuit that minimizes the temperature drift and hysteresis effects of the GMR sensor in the probe simultaneously are presented in this paper.
15 citations
Cites background or methods from "A New Inductive Proximity Sensor Ba..."
...This excitation was considered due to its multiple advantages presented in [16]....
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...Since the exciting flux B at a distance decreases with the diameter of the exciting coil (which further decreases Brf) [16], the exciting coil had to be suitably designed so that the GMR sensor received maximum Brf from metal targets that were far away....
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...Due to this reason, this probe was envisaged such that it will indicate the proximity of the impending shrapnel as its tip get closer, by varying the frequency of an audio signal using the automation program described in [16] during surgery....
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...Such measurements were possible, since the IPS had an inherent noise mitigating capability due to its differential sensing design....
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...It can be seen in [16] that the maximum DD obtained with the IPS-based probe was 20 mm....
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TL;DR: In this article, a dual-mode proximity sensor composed of inductive and capacitive sensing modes is presented, which can help the robot distinguish different objects and obtain distance information at the same time.
Abstract: Purpose
The purpose of this paper is to present a dual-mode proximity sensor composed of inductive and capacitive sensing modes, which can help the robot distinguish different objects and obtain distance information at the same time. A systematic study of sensor response to various objects and the function of cooperation sensing is needed. Furthermore, the application in the field of robotic area needs to be discussed.
Design/methodology/approach
Numerical modeling of each sensing modes and simulations based on finite element analysis method has been carried out to verify the designed dual-mode sensor. A number of objects composed of different materials are used to research the cooperation perception and proximity sensing functions. In addition, the proposed sensor is used on the palm of a mechanical hand as application experiment.
Findings
The characteristics of the sensor are summarized as follows: the sensing range of inductive mode is 0-5.6 mm for detecting a copper block and the perceive range of capacitive mode is 0-5.1 mm for detecting a plastic block. The collaborative perceive tests validated that the non-ferromagnetism metals can be distinguished by inductive mode. Correspondingly, ferromagnetism metals and dielectric objects are differentiated by capacitive mode. Application experiments results reveal that both plastic bottle and steel bottle could be detected and differentiated. The experimental results are in agreement with those of simulations.
Originality value
This paper provides a study of dual-mode proximity sensor in terms of design, experiments and application.
11 citations
TL;DR: The new contactless hand tremor detector can be developed as a clinical instrument for monitoring the fatigue symptoms of post-exercise and diagnosing the early Parkinson’s disease.
Abstract: A contactless detector is presented for evaluating hand tremors caused by exercise-induced fatigue and early Parkinson’s disease. The device consists of a spiral coil, a microcontroller, and an inductive sensor circuitry. Theory shows that the resonant frequency of the circuitry increases when the distance between the hand and the spiral coil decreases, thus small variations of distance from tremor can be detected from the changes of resonant frequencies. A mechanical hand was built for experiments to simulate human hand tremors with repeatability at a fixed frequency. The magnitudes and frequencies of the tremors in the mechanical hand were quantitatively identified using the inductive sensor. Hence, feasibility and accuracy of the contactless hand tremor detector were determined. A triaxial accelerometer was used for comparison. By comparing spectral distributions and magnitudes of the tremors, the inductive sensor performed better than the accelerometer. The detector was applied to evaluate actual hand tremors of three subjects who had undergone exercise to induce tremors. The tremor waveform amplitudes of the subjects were quantitatively analyzed by the standard deviations method. The increased signal energies of exercise-induced tremor within 8–12 Hz were confirmed. Then, a subject with early Parkinson’s disease was evaluated by the proposed hand tremor detector. The tremor magnitudes and frequencies of the patient hand were quantitatively identified within in 4–7 Hz. Therefore, the new contactless hand tremor detector can be developed as a clinical instrument for monitoring the fatigue symptoms of post-exercise and diagnosing the early Parkinson’s disease.
3 citations
DOI•
TL;DR: In this paper , perfect electric conductors (PECs) are reconstructed integrating the subspace-based optimization method (SOM) within the iterative multiscaling approach (IMSA), without a priori information on the number or/and the locations of the scatterers and modeling their electromagnetic (EM) scattering interactions with a (known) probing source in terms of surface electric field integral equations.
Abstract: Perfect electric conductors (PECs) are reconstructed integrating the subspace-based optimization method (SOM) within the iterative multiscaling approach (IMSA). Without a priori information on the number or/and the locations of the scatterers and modeling their electromagnetic (EM) scattering interactions with a (known) probing source in terms of surface electric field integral equations, a segment-based representation of PECs is retrieved from the scattered field samples. The proposed IMSA-SOM inversion method is validated against both synthetic and experimental data by assessing the reconstruction accuracy, the robustness to the noise, and the computational efficiency with some comparisons, as well.
1 citations
References
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Book•
01 Jan 1981
TL;DR: This authoritative compilation of formulas and tables simplifies the design of inductors for electrical engineers features a single simple formula for virtually every type of inductor, together with tables from which essential numerical factors may be interpolated.
Abstract: This authoritative compilation of formulas and tables simplifies the design of inductors for electrical engineers. It features a single simple formula for virtually every type of inductor, together with tables from which essential numerical factors may be interpolated. An esteemed reference, it belongs in the library of every electrical engineer. 1946 edition.
1,296 citations
"A New Inductive Proximity Sensor Ba..." refers background in this paper
...where l is the length of the leads lying parallel to each other and dl is the distance between them [19]....
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TL;DR: In this paper, the design methods for coils with air and ferromagnetic cores are compared and summarized, and the frequency properties of coil sensors are analyzed and various methods for output signal processing are presented, such as Rogowski coil, gradiometer sensors, vibrating coil sensors, tangential field sensors and needle probes.
Abstract: This review describes induction coil sensors, which are also known as search coils, pickup coils or magnetic loop sensors. The design methods for coils with air and ferromagnetic cores are compared and summarized. The frequency properties of coil sensors are analysed and various methods for output signal processing are presented. Special kinds of induction sensors, such as Rogowski coil, gradiometer sensors, vibrating coil sensors, tangential field sensors and needle probes are described. The applications of coil sensors as magnetic antennae are also presented.
529 citations
"A New Inductive Proximity Sensor Ba..." refers background in this paper
...In addition, adding a core brings nonlinearity in sensor output [11], [20]....
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TL;DR: In accordance with the sensor analysis presented in this paper, design strategies to compensate for important sensor imperfections are recommended and challenges that are associated with ECS interfaces are identified, with focus on advanced industrial applications.
Abstract: This paper presents a comprehensive study of the design aspects of eddy-current displacement sensor (ECS) systems. In accordance with the sensor analysis presented in this paper, design strategies to compensate for important sensor imperfections are recommended. To this end, the challenges that are associated with ECS interfaces are identified, with focus on advanced industrial applications. This paper also provides a technical overview of the design advances of ECS interfaces proposed in the last decade and evaluates their pros and cons. Recently reported interface solutions for demanding industrial applications with respect to high resolution, stability, bandwidth, and low power consumption, at a sufficiently high excitation frequency, are addressed in more detail.
120 citations
"A New Inductive Proximity Sensor Ba..." refers background or methods in this paper
...Besides, the parasitic inductance of Ze [21] can also influence the excitation current, affecting the repeatability of the measurements....
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...Drift in output due to heating of the sensor reduces the repeatability of measurements [21]....
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...Here, the excitation is an impulse current obtained using simple circuitry as compared with the sinusoidal oscillator-based schemes in [21],...
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TL;DR: A simple and efficient seat occupancy detector that combines inductive and capacitive proximity sensing principles and successfully senses human proximity and distinguishes it from other conductive objects is presented.
Abstract: This paper presents a simple and efficient seat occupancy detector. A seat occupancy detector is an integral part of the airbag safety system and, in its simplest form, provides the (occupied or vacant) status of the seat to the airbag control unit. Although the occupancy sensing methods based on a capacitive principle are efficient, they typically require electrodes to be placed in the surface layer of the sitting and backrest areas of the seat. The proposed sensor uses a simple electrode structure, and it is placed below the seat foam in the sitting area of the seat. These features promise a less-expensive sensor as it can be easily manufactured and installed in a seat. The new sensor combines inductive and capacitive proximity sensing principles. The sensor detects the presence of an occupant exploiting the shielding effect of the electric field while its inductive proximity feature senses the presence of conductive objects (e.g., laptop) that may be placed in the seat and helps to achieve reliable occupancy sensing. The measurement system uses a signal conditioning unit based on a carrier frequency principle. A prototype sensing system has been built, and its application as a seat occupancy sensing system in a vehicle has been verified. The developed system successfully senses human proximity and distinguishes it from other conductive objects.
100 citations
TL;DR: A novel inductive loop sensor that can detect vehicles under a heterogeneous and less-lane-disciplined traffic and thus can be used to support a traffic control management system in optimizing the best use of existing roads is presented.
Abstract: This paper presents a novel inductive loop sensor that can detect vehicles under a heterogeneous and less-lane-disciplined traffic and thus can be used to support a traffic control management system in optimizing the best use of existing roads. The loop sensor proposed in this paper detects large (e.g., bus) as well as small (e.g., bicycle) vehicles occupying any available space in the roadway, which is the main requirement for sensing heterogeneous and lane-less traffic. To accomplish the sensing of large as well as small vehicles, a multiple loop system with a new inductive loop sensor structure is proposed. The proposed sensor structure not only senses and segregates the vehicle type as bicycle, motor cycle, scooter, car, and bus but also enables accurate counting of the number of vehicles even in a mixed traffic flow condition. A prototype of the multiple loop sensing system has been developed and tested. Field tests indicate that the prototype successfully detected all types of vehicles and counted, correctly, the number of each type of vehicles. Thus, the suitability of the proposed sensor system for any type of traffic has been established.
92 citations
"A New Inductive Proximity Sensor Ba..." refers background in this paper
...Eddy-current sensors are used in many applications to detect metal targets [4]–[6]....
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