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Satoru Katsuda - One of the best experts on this subject based on the ideXlab platform.

  • SUZAKU SPECTROSCOPY OF VELA Shrapnel B
    The Astrophysical Journal, 2009
    Co-Authors: Hiroya Yamaguchi, Satoru Katsuda
    Abstract:

    We present the X-ray observation of Vela Shrapnel B with the X-ray Imaging Spectrometer on board the Suzaku satellite. The Shrapnel is one of several ejecta fragmentlike features protruding beyond the primary blast wave shock front of the Vela supernova remnant. The spectrum of Shrapnel B is well represented by a single-temperature thin-thermal plasma in a nonequilibrium ionization state. The elemental abundances of O, Ne, and Mg are found to be significantly higher than the solar values, supporting that Shrapnel B originates from supernova ejecta. The abundances of O, Ne, and Mg relative to Fe are enhanced above their solar values, while that of Si relative to Fe are at their solar values. This abundance pattern is similar to that in Shrapnel D, except that the enhancements of the lighter elements are less prominent, suggesting more extensive mixing with the interstellar medium (ISM) in Shrapnel B. The contribution of the ISM is considered to be larger at the trailing region, because the absolute abundances of some elements there are depleted relative to those at the Shrapnel's head.

  • suzaku spectroscopy of vela Shrapnel b
    arXiv: High Energy Astrophysical Phenomena, 2009
    Co-Authors: Hiroya Yamaguchi, Satoru Katsuda
    Abstract:

    We present the X-ray observation of Vela Shrapnel B with the XIS on board the Suzaku satellite. The Shrapnel is one of several ejecta fragment-like features protruding beyond the primary blast wave shock front of the Vela supernova remnant. The spectrum of Shrapnel B is well-represented by a single-temperature thin-thermal plasma in a non-equilibrium ionization state. The elemental abundances of O, Ne, and Mg are found to be significantly higher than the solar values, supporting that Shrapnel B originates from supernova ejecta. The abundances of O, Ne, and Mg relative to Fe are enhanced above their solar values, while that of Si relative to Fe are at their solar values. This abundance pattern is similar to that in Shrapnel D, except that the enhancements of the lighter elements are less prominent, suggesting more extensive mixing with the interstellar medium (ISM) in Shrapnel B. The contribution of the ISM is considered to be larger at the trailing region, because the absolute abundances of some elements there are depleted relative to those at the Shrapnel's head.

  • Origin of the Shrapnels around the Vela SNR
    New Astronomy Reviews, 2006
    Co-Authors: Hiroshi Tsunemi, Satoru Katsuda
    Abstract:

    Abstract There are several Shrapnels around the Vela SNR that originated from the inner layer of the progenitor star. We present here the analysis of the X-ray spectrum of the Vela Shrapnel A with XMM-Newton satellite. The Vela Shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. We confirmed that there was a prominent Si K α emission line showing a Si-rich plasma. The mass ratio between O and Si is 1.4:1. The Shrapnel D also shows metal rich abundance. The mass ratio of O, Ne and Mg is about 7:3:1. These mass ratios can be found in the 13 M ⊙ star. We estimate that the birth place of the Shrapnel A is the mass radius of 1.5 M ⊙ while that of the Shrapnel D is the mass radius of 1.64 M ⊙ .

  • Spatially Resolved X-ray Spectroscopy of Vela Shrapnel A
    The Astrophysical Journal, 2006
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    We present the detailed X-ray spectroscopy of Vela Shrapnel A with the XMM-Newton satellite. Vela Shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. The XMM-Newton image shows that Shrapnel A consists of a bright knot and a faint trailing wake. We extracted spectra from various regions, finding a prominent Si Ly$_\alpha$ emission line in all the spectra. All the spectra are well represented by the non-equilibrium ionization (NEI) model. The abundances are estimated to be O$\sim$0.3, Ne$\sim$0.9, Mg$\sim$0.8, Si$\sim$3, Fe$\sim$0.8 times their solar values. The non-solar abundance ratio between O and Si indicates that Shrapnel A originates from a deep layer of a progenitor star. We found that the relative abundances between heavy elements are almost uniform in Shrapnel A, which suggests that the ejecta from supernova explosion are well mixed with swept-up interstellar medium.

  • spatially resolved x ray spectroscopy of vela Shrapnel a
    The Astrophysical Journal, 2006
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    We present detailed X-ray spectroscopy of Vela Shrapnel A with the XMM-Newton satellite. Vela Shrapnel A is one of several protrusions identified as bullets from the Vela supernova explosion. The XMM-Newton image shows that Shrapnel A consists of a bright knot and a faint trailing wake. We extracted spectra from various regions, finding a prominent Si Lyα emission line in all the spectra. All the spectra are well represented by the nonequilibrium ionization (NEI) model. The abundances are estimated to be O ~ 0.3, Ne ~ 0.9, Mg ~ 0.8, Si ~ 3, and Fe ~ 0.8 times their solar values. The nonsolar abundance ratio between O and Si indicates that Shrapnel A originates from a deep layer of a progenitor star. We found that the relative abundances between heavy elements are almost uniform in Shrapnel A, which suggests that the ejecta from the supernova explosion are well mixed with swept-up interstellar medium.

Hiroshi Tsunemi - One of the best experts on this subject based on the ideXlab platform.

  • Origin of the Shrapnels around the Vela SNR
    New Astronomy Reviews, 2006
    Co-Authors: Hiroshi Tsunemi, Satoru Katsuda
    Abstract:

    Abstract There are several Shrapnels around the Vela SNR that originated from the inner layer of the progenitor star. We present here the analysis of the X-ray spectrum of the Vela Shrapnel A with XMM-Newton satellite. The Vela Shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. We confirmed that there was a prominent Si K α emission line showing a Si-rich plasma. The mass ratio between O and Si is 1.4:1. The Shrapnel D also shows metal rich abundance. The mass ratio of O, Ne and Mg is about 7:3:1. These mass ratios can be found in the 13 M ⊙ star. We estimate that the birth place of the Shrapnel A is the mass radius of 1.5 M ⊙ while that of the Shrapnel D is the mass radius of 1.64 M ⊙ .

  • Spatially Resolved X-ray Spectroscopy of Vela Shrapnel A
    The Astrophysical Journal, 2006
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    We present the detailed X-ray spectroscopy of Vela Shrapnel A with the XMM-Newton satellite. Vela Shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. The XMM-Newton image shows that Shrapnel A consists of a bright knot and a faint trailing wake. We extracted spectra from various regions, finding a prominent Si Ly$_\alpha$ emission line in all the spectra. All the spectra are well represented by the non-equilibrium ionization (NEI) model. The abundances are estimated to be O$\sim$0.3, Ne$\sim$0.9, Mg$\sim$0.8, Si$\sim$3, Fe$\sim$0.8 times their solar values. The non-solar abundance ratio between O and Si indicates that Shrapnel A originates from a deep layer of a progenitor star. We found that the relative abundances between heavy elements are almost uniform in Shrapnel A, which suggests that the ejecta from supernova explosion are well mixed with swept-up interstellar medium.

  • spatially resolved x ray spectroscopy of vela Shrapnel a
    The Astrophysical Journal, 2006
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    We present detailed X-ray spectroscopy of Vela Shrapnel A with the XMM-Newton satellite. Vela Shrapnel A is one of several protrusions identified as bullets from the Vela supernova explosion. The XMM-Newton image shows that Shrapnel A consists of a bright knot and a faint trailing wake. We extracted spectra from various regions, finding a prominent Si Lyα emission line in all the spectra. All the spectra are well represented by the nonequilibrium ionization (NEI) model. The abundances are estimated to be O ~ 0.3, Ne ~ 0.9, Mg ~ 0.8, Si ~ 3, and Fe ~ 0.8 times their solar values. The nonsolar abundance ratio between O and Si indicates that Shrapnel A originates from a deep layer of a progenitor star. We found that the relative abundances between heavy elements are almost uniform in Shrapnel A, which suggests that the ejecta from the supernova explosion are well mixed with swept-up interstellar medium.

  • Spatially Resolved Spectral Analysis of Vela Shrapnel D
    Publications of the Astronomical Society of Japan, 2005
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    The ROSAT all-sky survey discovered several ‘Shrapnels’, showing boomerang structures outside the Vela supernova remnant. We observed Shrapnel D with the XMM-Newton satellite. There is an X-ray bright ridge structure in our FOV running from north to south. Applying the VNEI model to X-ray spectra of various regions, we find that the plasma in the eastern part from the X-ray ridge is significantly different from that in the western part. The X-ray spectra in the western part can be represented by a single-temperature component. The abundances of heavy elements are almost uniform, whereas they are heavily overabundant, except for Fe; the relative abundances to the solar values are O∼ 5, Ne∼ 10, Mg∼ 10, Fe∼ 1. This indicates that Shrapnel D originated from the ejecta of the supernova. We find that the plasma in the eastern part from the ridge consists of two components with different temperatures; the hot component comes from the ejecta, while the cold component comes from the interstellar matter. These two components are considered to be in contact with each other, forming a contact discontinuity. Around the northern part of the contact discontinuity, we find wave-like structures of which the typical scale are comparable with that of the Rayleigh–Taylor instability.

  • XMM-Newton observation of Vela Shrapnel D
    Advances in Space Research, 2005
    Co-Authors: Satoru Katsuda, Hiroshi Tsunemi
    Abstract:

    Abstract The ROSAT all-sky survey discovered several ‘Shrapnels’, showing boomerang structures outside the Vela SNR. We observed the Shrapnel D in the eastern limb of the Vela SNR with the XMM-Newton satellite. There is an X-ray bright ridge structure in our FOV running from north to south. There is also an optical bright ridge structure running parallel to that in X-ray about 3′ in the east. These suggest that the Shrapnel D is now interacting with an interstellar cloud. Applying the VNEI model to X-ray spectra of various regions, we find that the plasma state of the eastern region of the X-ray ridge is significantly different from that of the western region. The X-ray spectra in the western region can be well fitted with a single temperature component. Abundances of heavy elements are almost uniform, whereas they are heavily overabundant (except Fe): the relative abundances to the solar values are O ∼5, Ne ∼8, Mg ∼8, Fe ∼1. It must have originated from the ejecta of the SN. We find that the plasma in the eastern part of the ridge consists of two temperature components: one component (hot plasma) representing the ejecta while the other (cold plasma) represents the interstellar cloud or swept-up ISM. These two components must have contacted to each other, indicating to form a contact discontinuity. Around northern part of the contact discontinuity, we found wavelike structures of which the typical scales are comparable with that of the Rayleigh–Taylor instability.

Sasaki M. - One of the best experts on this subject based on the ideXlab platform.

  • Indications of a Si-rich bilateral jet of ejecta in the Vela SNR observed with XMM-Newton
    2019
    Co-Authors: García F., Miceli M., Bocchino F., Orlando S., Suárez, Alejandra Etelvina, Combi, Jorge Ariel, Sasaki M.
    Abstract:

    Context. The Vela supernova remnant displays several ejecta, which are fragment-like features protruding beyond the front of its primary blast shock wave. They appear to be "Shrapnel", bowshock-shaped relics of the supernova explosion. One of these pieces of Shrapnel (A), located in the northeastern edge of the remnant, is peculiar because its X-ray spectrum exhibits a high Si abundance, in contrast to the other observed ejecta fragments, which show enhanced O, Ne, and Mg abundances. Aims. In this Letter we present the analysis of another ejecta fragment located opposite to Shrapnel A with respect to the center of the shell, in the southwestern boundary of the remnant, named Shrapnel G. We aim to fully characterize its X-ray emission to gather new information about the core-collapse supernova explosion mechanism. Methods. We thoroughly analyzed a dedicated XMM-Newton observation of Shrapnel G by producing background-subtracted and exposure-corrected maps in different energy ranges, which we complemented with a spatially resolved spectral analysis of the X-ray emission. Results. The fragment presents a bowshock-like shape with its anti-apex pointing to the center of the remnant. Its X-ray spectrum is best fit by a thermal plasma out of equilibrium of ionization with low O and Fe, roughly solar Ne and Mg, and a significantly high Si abundance, which is required to fit a very clear Si line at ∼1.85 keV. Its chemical composition and spectral properties are compatible with those of Shrapnel A, which is located on the opposite side of the remnant. Conclusions. As a consequence of the nucleosynthesis, pieces of Si-rich Shrapnel are expected to originate in deeper layers of the progenitor star compared to ejecta with lower-Z elements. A high velocity and density contrast with respect to the surrounding ejecta are necessary to make Shrapnel A and G overtake the forward shock. The line connecting Shrapnel A and G crosses almost exactly the expansion center of the remnant, strongly suggesting a Si-rich jet-counterjet structure, reminiscent of that observed in the young remnant Cas A.Facultad de Ciencias Astronómicas y Geofísica

  • Indications of a Si-rich bilateral jet of ejecta in the Vela SNR observed with XMM-Newton
    'EDP Sciences', 2017
    Co-Authors: García F., Suárez A. E., Miceli M., Bocchino F., Combi J. A., Orlando S., Sasaki M.
    Abstract:

    The Vela supernova remnant displays several ejecta, which are fragment-like features protruding beyond the front of its primary blast shock wave. They appear to be "Shrapnel", bowshock-shaped relics of the supernova explosion. One of these pieces of Shrapnel (A), located in the northeastern edge of the remnant, is peculiar because its X-ray spectrum exhibits a high Si abundance, in contrast to the other observed ejecta fragments, which show enhanced O, Ne, and Mg abundances. We present the analysis of another fragment located opposite to Shrapnel A with respect to the center of the shell, in the southwestern boundary of the remnant, named Shrapnel G. We thoroughly analyzed a dedicated XMM-Newton observation of Shrapnel G by producing background-subtracted and exposure-corrected maps in different energy ranges, which we complemented with a spatially resolved spectral analysis of the X-ray emission. The fragment presents a bowshock-like shape with its anti-apex pointing to the center of the remnant. Its X-ray spectrum is best fit by a thermal plasma out of equilibrium of ionization with low O and Fe, roughly solar Ne and Mg, and a significantly high Si abundance, which is required to fit a very clear Si line at ~1.85 keV. Its chemical composition and spectral properties are compatible with those of Shrapnel A, which is located on the opposite side of the remnant. As a consequence of the nucleosynthesis, pieces of Si-rich Shrapnel are expected to originate in deeper layers of the progenitor star compared to ejecta with lower-Z elements. A high velocity and density contrast with respect to the surrounding ejecta are necessary to make Shrapnel A and G overtake the forward shock. The line connecting Shrapnel A and G crosses almost exactly the expansion center of the remnant, strongly suggesting a Si-rich jet-counterjet structure, reminiscent of that observed in the young remnant Cas A.Comment: 5 pages, 4 figures. Accepted for publication in Astronomy & Astrophysics Letter

  • Indications of a Si-rich bilateral jet of ejecta in the Vela SNR observed with XMM-Newton
    'EDP Sciences', 2017
    Co-Authors: Miceli M., Bocchino F., Orlando S., Combi J., Sasaki M.
    Abstract:

    Context. The Vela supernova remnant displays several ejecta, which are fragment-like features protruding beyond the front of its primary blast shock wave. They appear to be "Shrapnel", bowshock-shaped relics of the supernova explosion. One of these pieces of Shrapnel (A), located in the northeastern edge of the remnant, is peculiar because its X-ray spectrum exhibits a high Si abundance, in contrast to the other observed ejecta fragments, which show enhanced O, Ne, and Mg abundances. Aims. In this Letter we present the analysis of another ejecta fragment located opposite to Shrapnel A with respect to the center of the shell, in the southwestern boundary of the remnant, named Shrapnel G. We aim to fully characterize its X-ray emission to gather new information about the core-collapse supernova explosion mechanism. Methods. We thoroughly analyzed a dedicated XMM-Newton observation of Shrapnel G by producing background-subtracted and exposure-corrected maps in different energy ranges, which we complemented with a spatially resolved spectral analysis of the X-ray emission. Results. The fragment presents a bowshock-like shape with its anti-apex pointing to the center of the remnant. Its X-ray spectrum is best fit by a thermal plasma out of equilibrium of ionization with low O and Fe, roughly solar Ne and Mg, and a significantly high Si abundance, which is required to fit a very clear Si line at \ue2\u88\ubc1.85 keV. Its chemical composition and spectral properties are compatible with those of Shrapnel A, which is located on the opposite side of the remnant. Conclusions. As a consequence of the nucleosynthesis, pieces of Si-rich Shrapnel are expected to originate in deeper layers of the progenitor star compared to ejecta with lower-Z elements. A high velocity and density contrast with respect to the surrounding ejecta are necessary to make Shrapnel A and G overtake the forward shock. The line connecting Shrapnel A and G crosses almost exactly the expansion center of the remnant, strongly suggesting a Si-rich jet-counterjet structure, reminiscent of that observed in the young remnant Cas A

  • Indications of a Si-rich bilateral jet of ejecta in the Vela SNR observed with XMM-Newton
    'EDP Sciences', 2017
    Co-Authors: García Federico, Miceli M., Bocchino F., Orlando S., Suárez, Alejandra Etelvina, Combi, Jorge Ariel, Sasaki M.
    Abstract:

    Context. The Vela supernova remnant displays several ejecta, which are fragment-like features protruding beyond the front of its primary blast shock wave. They appear to be "Shrapnel", bowshock-shaped relics of the supernova explosion. One of these pieces of Shrapnel (A), located in the northeastern edge of the remnant, is peculiar because its X-ray spectrum exhibits a high Si abundance, in contrast to the other observed ejecta fragments, which show enhanced O, Ne, and Mg abundances. Aims. In this Letter we present the analysis of another ejecta fragment located opposite to Shrapnel A with respect to the center of the shell, in the southwestern boundary of the remnant, named Shrapnel G. We aim to fully characterize its X-ray emission to gather new information about the core-collapse supernova explosion mechanism. Methods. We thoroughly analyzed a dedicated XMM-Newton observation of Shrapnel G by producing background-subtracted and exposure-corrected maps in different energy ranges, which we complemented with a spatially resolved spectral analysis of the X-ray emission. Results. The fragment presents a bowshock-like shape with its anti-apex pointing to the center of the remnant. Its X-ray spectrum is best fit by a thermal plasma out of equilibrium of ionization with low O and Fe, roughly solar Ne and Mg, and a significantly high Si abundance, which is required to fit a very clear Si line at ∼1.85 keV. Its chemical composition and spectral properties are compatible with those of Shrapnel A, which is located on the opposite side of the remnant. Conclusions. As a consequence of the nucleosynthesis, pieces of Si-rich Shrapnel are expected to originate in deeper layers of the progenitor star compared to ejecta with lower-Z elements. A high velocity and density contrast with respect to the surrounding ejecta are necessary to make Shrapnel A and G overtake the forward shock. The line connecting Shrapnel A and G crosses almost exactly the expansion center of the remnant, strongly suggesting a Si-rich jet-counterjet structure, reminiscent of that observed in the young remnant Cas A.Fil: García, Federico. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Suárez, Alejandra Etelvina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Miceli, M.. Università degli Studi di Palermo; ItaliaFil: Bocchino, F.. Università degli Studi di Palermo; ItaliaFil: Combi, Jorge Ariel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Orlando, S.. Universita Degli Studi Di Palermo; ItaliaFil: Sasaki, M.. Friedrich-Alexander-Universität Erlangen-Nürnberg; Alemani

Bernd Aschenbach - One of the best experts on this subject based on the ideXlab platform.

  • Chandra X-Ray Observatory Study of Vela Shrapnel A
    The Astrophysical Journal, 2001
    Co-Authors: Emi Miyata, Hiroshi Tsunemi, Bernd Aschenbach, Koji Mori
    Abstract:

    We present high-resolution Chandra observations of Shrapnel A in the vicinity of the Vela supernova remnant. The Chandra image reveals a bright X-ray region at the head position of Shrapnel A and a fainter extended tail. The spectral analysis shows that the plasma is in a condition of nonequilibrium ionization. The abundance of O is 0.34 times that of the solar value, whereas that of Si is 3 times solar, showing an anomalous abundance ratio for the two elements. The ionization timescale indicates that the Shrapnel had been heated up about 104 yr ago. We confirm that the pressure in the head region is 10 times higher than that in the tail region, which is not explained by a simple blast-wave model. These facts strongly support the view that Shrapnel A is a fragment of the progenitor star created in the supernova explosion.

  • Spectroscopic Study of the Vela-Shrapnel
    Publications of the Astronomical Society of Japan, 1999
    Co-Authors: Hiroshi Tsunemi, Emi Miyata, Bernd Aschenbach
    Abstract:

    Several Shrapnels have been detected in the vicinity of Vela SNR by the ROSAT all-sky survey. We present here the spectral properties of Shrapnel 'A' observed with the ASCA satellite. A prominent Si-K emission line with relatively weak emission lines from other elements have been detected, revealing that the relative abundance of Si is a few ten-times higher than those of other elements. Combining with the ROSAT PSPC results, we obtained the electron temperature, kTe, to be 0.33 ± 0.01 keV. The total mass of Shrapnel 'A' is estimated to be ~ 0.01 M®. If it is an ejecta of a supernova explosion, the interstellar matter would be swept up in the leading edge while the ejecta material would be peeled off in the trailing edge, which should be confirmed by future observations.

Mohanasankar Sivaprakasam - One of the best experts on this subject based on the ideXlab platform.

  • MeMeA - Locating metal Shrapnel in human body using GMR sensors
    2014 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2014
    Co-Authors: Mithun Sakthivel, Mohanasankar Sivaprakasam, Boby George, V. Jagadeesh Kumar
    Abstract:

    Injury due to metal Shrapnel is a major cause of death in victims of bomb blast, land mines and gun fire. To recover these Shrapnel surgically, surgeons use imaging systems for locating them inside the victim's body. Since these Shrapnel are normally mobile, by the time the surgery starts, their positions would have changed making it very difficult for the surgeon to recover them. In certain cases, the Shrapnel that are visible in the images can become untraceable during surgery. Giant Magneto Resistance (GMR) type sensor based tool to aid a surgeon to locate Shrapnel was found to have poor depth response characteristics compared to inductive proximity sensor based tool. This paper presents the details of new schemes that were evaluated to improve the detection depths of the GMR sensor based Shrapnel detectors. Results on prototype detectors built and tested establish the feasibility of the proffered schemes.

  • Packaging and evaluation of an online tool for locating metal Shrapnel during surgery
    2014 Annual IEEE India Conference (INDICON), 2014
    Co-Authors: Mithun Sakthivel, Boby George, Mohanasankar Sivaprakasam
    Abstract:

    A major cause of death in victims of bomb blast, land mines and gunfire is injury due to metal Shrapnel. The present approach adopted by doctors to recover these metal Shrapnel is to locate them via X-ray/CT images before surgery and then cut open the located area for their removal. But this approach is not always successful as there were cases in which the Shrapnel was visible clearly in the images, but during surgery the doctors could not trace it. Hence based on a clinical requirement, a minimally invasive online probe was developed to guide doctors to the location of the Shrapnel during surgery. The sensor used in the probe was a miniaturized Inductive Proximity Sensor which was powered using a novel excitation. In this paper, the packaging of this Shrapnel detecting probe into a new online tool and its evaluation in a surgery-like scenario is presented. Some errors were found during the various stages of evaluation and these were corrected using suitable corrective measures. The details of these corrective measures are also presented in this paper.

  • A New Inductive Proximity Sensor Based Guiding Tool to Locate Metal Shrapnel During Surgery
    IEEE Transactions on Instrumentation and Measurement, 2014
    Co-Authors: Mithun Sakthivel, Boby George, Mohanasankar Sivaprakasam
    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.

  • a new inductive proximity sensor as a guiding tool for removing metal Shrapnel during surgery
    Instrumentation and Measurement Technology Conference, 2013
    Co-Authors: Mithun Sakthivel, Boby George, V. Jayashankar, Mohanasankar Sivaprakasam
    Abstract:

    In this paper, an inductive proximity sensor with a longer range when compared to its diameter is presented. This sensor is intended to guide doctors, while performing surgery to remove metal Shrapnel from victims of bomb blasts, gun fire, land mines etc. Presently doctors rely on imaging systems to locate Shrapnel in the victim's body before surgery. Effectiveness of surgery and recovery solely depends on the doctors' skill to trace the Shrapnel. In some cases the Shrapnel may be visible in the images, but it may be untraceable during surgery. So in such cases, an inductive proximity sensor which is small enough to be introduced into the victim's body and can direct the recovery tool effectively to the exact location of the Shrapnel, during the surgery, will be very useful to the doctor. Such a sensor, along with its details and experimental results are presented in this paper. This sensor works on a new comparison based method to detect tiny targets, as the detector size is a constraint here. The sensor can detect Shrapnel materials such as steel, brass and Aluminium. A smaller, modified version of this sensor is also presented in the paper, along with a study of the effect of body tissues on sensor performance.

  • A GMR sensor based guiding tool for location of metal Shrapnel during surgery
    2013 Seventh International Conference on Sensing Technology (ICST), 2013
    Co-Authors: Meera Sakthivel, Boby George, Mohanasankar Sivaprakasam
    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.