A new inductive proximity sensor as a guiding tool for removing metal shrapnel during surgery

A New Inductive Proximity Sensor Based Guiding Tool to Locate Metal Shrapnel During Surgery

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.

Embedded Inductive Sensor System in Helping Industrial Machine Maintenance Problems

Abstract: The inductive sensor / proximity sensor was preliminarily initiated to be used as a micro level limit switch where its potential in speed measurement was not taken advantage by the industries. Thus, looking into its potential significant contribution, this paper presents the performance of a non-contact inductive sensor which was used to remotely measure the high speed rotational spindle with high degree of accuracy. The sensor was used to generate pulse correlating the rotational speed of a machine. An experiment was conducted using a self-designed test rig to investigate its performance in counting the machine spindle speed which can help to ease the machine maintenance task for technical supports. The measuring was monitored by a specially designed LCD display, connected to an electronic circuit and a microcontroller. The test result shows that the inductive proximity sensor yields up to 95% in terms of rotational speed accuracy. The setup was made to suit a single monitoring system, while the modular based for multiple systems that integrate different operations are in progress.

A GMR sensor based guiding tool for location of metal shrapnel during surgery

Abstract: Shrapnel injury is a major cause of death in victims of bomb blast, land mines and gun fire. In this paper, a Giant Magneto Resistance (GMR) sensor based online surgical tool that helps to remove metal shrapnel from victim's body is presented. This tool is intended to guide the surgeon to the exact location of the shrapnel during surgery. Presently doctors rely on imaging systems to locate them before surgery. Effectiveness of surgery solely depends on the doctors' skill to trace them, as these images do not provide real-time information of the location of the shrapnel during surgery. Therefore, in some cases, the shrapnel, in spite of being visible in the images, may become untraceable during surgery. So in such cases, a sensing tool that can guide the doctor to the location of the shrapnel will be very effective. An inductive proximity sensor can serve this purpose, but its output can be affected by its lead inductance or other parasitic circuit parameters. Therefore in order to overcome such effects, a GMR based sensing tool is proposed here. The details and experimental results obtained from this tool are presented in this paper. The tool can detect both ferromagnetic and paramagnetic metal targets.

Low-cost data logging and telemetry system for All-Terrain Vehicle performance analysis

Abstract: Rapid advancements in the field of embedded systems have facilitated the development of cost-effective complex projects with innovative outcomes. These advancements also apply for the automotive racing domain in the form of digital data extraction and wireless communication. It is of utmost importance to have a system in racing vehicles that will cater real-time data to the race engineers using which the process of troubleshooting the vehicle in the pit can be aided. In this manuscript, a data logging and a telemetry system for an All-Terrain Vehicle (ATV) has been developed by Team Torpedo, the ATV racing team of Amrita School of Engineering, Coimbatore. The team participates in national amateur off-road racing competitions that see an attendance of over 250 reputed college teams from different parts of the country. This system is based on a low-cost embedded platform powered by an Arduino Mega 2560 microcontroller. Important parameters like speed, G forces, GPS coordinates, etc. are logged in a microSD card which is used for validating the ATVs design and standardize its performance. During the racing events, the collected data is wirelessly transmitted to the pit using the Zigbee protocol over a reasonably large distance. In the receiver's end, the data is graphically rendered for the race engineers to assess the ATV's real-time performance.

An Implementation Method for an Inductive Proximity Sensor with an Attenuation Coefficient of 1

Abstract: In order to achieve long-distance measurement, a bridge differential inductance detection circuit is employed; on this basis, an automatic zero adjustment technique for sensors using an integral–proportional-integral controller is proposed in this work to achieve consistent product production and efficient installation and debugging, and the mathematical model of the bridge differential inductance detection circuit is established to effectively design the controller parameters. Furthermore, an implementation method for an inductive proximity sensor with an attenuation coefficient of 1 is also proposed based on the bridge differential inductance detection circuit by querying the proximity distance table in the field-programmable gate array (FPGA) to detect multiple target metal objects at the same inductive distance. Simulation and experimental results show that the proposed method is correct and effective.

The dielectric properties of biological tissues: I. Literature survey

Abstract: The dielectric properties of tissues have been extracted from the literature of the past five decades and presented in a graphical format. The purpose is to assess the current state of knowledge, expose the gaps there are and provide a basis for the evaluation and analysis of corresponding data from an on-going measurement programme.

Design Strategies for Eddy-Current Displacement Sensor Systems: Review and Recommendations

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.

Basic analysis of a metal detector

Abstract: Metal detectors are extensively used to find undesirable metal objects in processed food. In such a typical metal detector, the coils are coaxially arranged with the transmitting coil in the center and two receiving coils on the sides. The receiving coils are connected to a differential amplifier. When the magnetic field generated in the transmitting coil is disturbed by metal objects, the amplitude and phase of the output voltage of the differential amplifier change, and, thus, the existence of foreign metal pieces is detected. The relationship between the amplitude and phase of the output and the electromagnetic properties of the metal objects, however, has only been discussed experimentally so far. The authors have already developed the SRPM method to simultaneously estimate the electrical and magnetic properties of a spherical sample by vectorially measuring the difference in the impedance of two circular solenoid coils, one with and the other without a sample. An attempt is made to theoretically analyze the properties, such as size, conductivity, and permeability of the metal objects from the output, i.e., amplitude and phase of the metal detector. Based on this method, an equation to estimate the vector voltage induced in the receiving coil by the metal object is derived by using a spherical sample to simplify the analysis.

Facing the new threats of terrorism: radiologists' perspectives based on experience in Israel

Abstract: On September 11, 2001, the world changed. The vicious giant of terrorism that was dormant until that date had arisen. After the horrific mass-casualty terror attack on the United States, any and all forms of assault seem possible. Owing to the complexity of injuries encountered in terror attack victims, fast and accurate imaging plays an essential role in triage and identification of abnormalities associated with injuries. The radiologist becomes a crucial part of the first-line team of doctors treating these patients. Knowledge that the best available treatment is given to terror attack victims can enhance the strength and endurance of society against terror. On the basis of the authors' experience with terror events in Israel, the steps involved in imaging of terror attack patients include conventional radiography, focused abdominal sonography in trauma, computed tomography, and angiography, with the judicious use of supplemental imaging.

Pulse Induction Metal Detector Using Sample and Hold Method

Abstract: This paper presents the Pulse Induction Metal Detector Using Sample and Hold Method. The proposed method is to measure output voltage from search coil. The system consists of the pulse generator circuit, amplifier circuit, integrator circuit, three mono-stable circuits, sample and hold circuit, comparator circuit and display circuit. The voltage output signal of the proposed technique is proportional to size, shape and type of metal target. The metal target with differential size was used in our experiment as an illustrative case study. Experimental results show that the proposed method can detect metal with satisfied sensitivity and good linearity.