The Experts below are selected from a list of 822 Experts worldwide ranked by ideXlab platform

Reid R. Harrison - One of the best experts on this subject based on the ideXlab platform.

  • Wireless neural recording with single low-powered integrated circuit
    2016
    Co-Authors: Reid R. Harrison, R.j. Kier, Florian Solzbacher, Cynthia A. Chestek, Krishna V. Shenoy, Student Member, Senior Member
    Abstract:

    Abstract—We present benchtop and in vivo experimental results from an integrated circuit designed for wireless implantable neural recording applications. The chip, which was fabricated in a commercially available 0.6- m 2P3M BiCMOS process, contains 100 amplifiers, a 10-bit analog-to-digital converter (ADC), 100 threshold-based spike detectors, and a 902–928 MHz frequency-shift-keying (FSK) transmitter. Neural signals from a selected amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power/command receiving coil and a 100-Nf Capacitor. Index Terms — Brain–machine interface (BMI), low power

  • Wireless Neural Recording With Single Low-Power Integrated Circuit
    IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 2009
    Co-Authors: Reid R. Harrison, R.j. Kier, Bradley Greger, Florian Solzbacher, Cynthia A. Chestek, Vikash Gilja, Paul Nuyujukian, Stephen I. Ryu, Krishna V. Shenoy
    Abstract:

    We present benchtop and in vivo experimental results from an integrated circuit designed for wireless implantable neural recording applications. The chip, which was fabricated in a commercially available 0.6- mum 2P3M BiCMOS process, contains 100 amplifiers, a 10-bit analog-to-digital converter (ADC), 100 threshold-based spike detectors, and a 902-928 MHz frequency-shift-keying (FSK) transmitter. Neural signals from a selected amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power/command receiving coil and a 100-Nf Capacitor.

  • A Wireless Integrated Circuit for 100-Channel Charge-Balanced Neural Stimulation
    IEEE transactions on biomedical circuits and systems, 2009
    Co-Authors: B.k. Thurgood, David J. Warren, Noah M. Ledbetter, Gregory A. Clark, Reid R. Harrison
    Abstract:

    The authors present the design of an integrated circuit for wireless neural stimulation, along with benchtop and in - vivo experimental results. The chip has the ability to drive 100 individual stimulation electrodes with constant-current pulses of varying amplitude, duration, interphasic delay, and repetition rate. The stimulation is performed by using a biphasic (cathodic and anodic) current source, injecting and retracting charge from the nervous system. Wireless communication and power are delivered over a 2.765-MHz inductive link. Only three off-chip components are needed to operate the stimulator: a 10-Nf Capacitor to aid in power-supply regulation, a small Capacitor (< 100 pF) for tuning the coil to resonance, and a coil for power and command reception. The chip was fabricated in a commercially available 0.6- mum 2P3M BiCMOS process. The chip was able to activate motor fibers to produce muscle twitches via a Utah Slanted Electrode Array implanted in cat sciatic nerve, and to activate sensory fibers to recruit evoked potentials in somatosensory cortex.

  • ISCAS - Wireless neural signal acquisition with single low-power integrated circuit
    2008 IEEE International Symposium on Circuits and Systems, 2008
    Co-Authors: Reid R. Harrison, R.j. Kier, Bradley Greger, Florian Solzbacher, Cynthia A. Chestek, Vikash Gilja, Paul Nuyujukian, Stephen I. Ryu, Krishna V. Shenoy
    Abstract:

    We present experimental results from an integrated circuit designed for wireless neural recording applications. The chip, which was fabricated in a 0.6-mum 2P3M BiCMOS process, contains 100 amplifiers and a 10-bit ADC and 902-928 MHz FSK transmitter. Neural signals from one amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power receive coil and a 100-Nf Capacitor.

  • Wireless integrated circuit for 100-channel neural stimulation
    2008 IEEE Biomedical Circuits and Systems Conference, 2008
    Co-Authors: B.k. Thurgood, David J. Warren, Noah M. Ledbetter, Gregory A. Clark, Reid R. Harrison
    Abstract:

    We present the design of an integrated circuit for wireless neural stimulation, along with bench-top and in-vivo experimental results. The chip has the ability to drive 100 individual stimulation electrodes with constant-current pulses of varying amplitude, duration, interphasic delay, and repetition rate. The stimulation is done using a biphasic (cathodic and anodic) current source, injecting and retracting charge from the nervous system. Wireless communication and power are achieved over a 2.765-MHz inductive link. Only two off-chip components are needed to operate the stimulator: a 10-Nf Capacitor to aid in power supply regulation and a coil for power and command reception. The chip was fabricated in a commercially available 0.6-mum 2P3M BiCMOS process. The chip was able to activate motor fibers to produce muscle twitches via a Utah Slanted Electrode Array implanted in cat sciatic nerve, and to activate sensory fibers to recruit evoked potentials in somatosensory cortex.

Jose Moreno - One of the best experts on this subject based on the ideXlab platform.

  • demonstration of neutron production in a table top pinch plasma focus device operating at only tens of joules
    Journal of Physics D, 2008
    Co-Authors: Leopoldo Soto, Patricio Silva, Jose Moreno, Marcelo Zambra, Luis Altamirano, A Clausse, W. Kies, Roberto E Mayer, Cristian Pavez, Luis Huerta
    Abstract:

    Neutron emission from a deuterium plasma pinch generated in a very small plasma focus (6 mm anode diameter) operating at only tens of joules is presented. A maximum current of 50 kA is achieved 140 ns after the beginning of the discharge, when the device is charged at 50 J (160 Nf Capacitor bank, 38 nH, 20–30 kV, 32–72 J). Although the stored energy is very low, the estimated energy density in the plasma and the energy per particle in the plasma are of the same order as in higher energy devices. The dependence of the neutron yield on the filling pressure of deuterium was obtained for discharges with 50 and 67 J stored in the Capacitor bank. Neutrons were measured by means of a system based on a 3He proportional counter in current mode. The average neutron yield for 50 J discharges at 6 mbar was (1.2 ± 0.5) × 104 neutrons per shot, and (3.6 ± 1.6) × 104 for 67 J discharges at 9 mbar. The maximum energy of the neutrons was (2.7 ± 1.8) MeV. Possible applications related to substance detection and others are discussed.

  • Axial and radial measurements of the neutron emission from miniature plasma focus devices
    2004
    Co-Authors: Jose Moreno, Patricio Silva, Leopoldo Soto
    Abstract:

    As first step of a program to design a repetitive pulsed neutron generator for applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Neutron emission has been obtained in both devices operating in deuterium. An especial techniques was necessary to develop in order to detect neutron pulsed of 104 neutrons per shot. The maximum total neutron yield measured was of the order of 106 and 104 neutrons per shot in the PF-400J and PF-50J respectively. Axial and radial measurements of the neutron emission are presented and the anisotropy is evaluated in this work. The neutrons are measured by pairs of silver activation counters, 3He detectors and scintillator-photomultiplier detectors.

  • Hard X-ray sources from miniature plasma focus devices
    2004
    Co-Authors: Verónica Raspa, Patricio Silva, Jose Moreno, Marcelo Zambra, Leopoldo Soto
    Abstract:

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Hard X-rays are being studied in these devices operating in hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400J. An effective energy of the order of 90keV was measured under those conditions. X ray images of different metallic objects also have been obtained.

  • Pinch evidence in a fast and small plasma focus of only tens of joules
    Plasma Sources Science and Technology, 2004
    Co-Authors: Patricio Silva, Leopoldo Soto, W. Kies, Jose Moreno
    Abstract:

    The pinch evidence in a deuterium-filled plasma focus (PF) of only tens of joules is presented. The system operates at a very low energy in the tens of joules range (160 Nf Capacitor bank, 38 nH, 20–35 kV, 32–98 J, ~150 ns current rise time), maintaining the same energy density as in large devices. The typical dip in the current derivative signal and the typical peak in the voltage signal observed in PF devices with energies of 1–1000 kJ, which are associated with pinch compression, were observed in a deuterium-filled PF operating at 50 and 67 J. The time to pinch and time to the peak current versus deuterium filled pressure were also obtained.

  • Plasma motion observations in a very small plasma focus in the limit of low energy
    Revista Mexicana De Fisica, 2003
    Co-Authors: Leopoldo Soto, Patricio Silva, Jose Moreno, Luis Altamirano, A Clausse
    Abstract:

    A very small plasma focus device has been designed and constructed. The plasma focus operates in the limit of low energy (160 Nf Capacitor bank, 65 nH, 20 - 40 kV, ∼ 32 - 100 J). The design of the electrode was assisted by a simple model of a Mather plasma focus. A neutron yield of 10 4 - 10 5 is expected when the discharge is operated with deuterium. Experiments in H 2 has been performed at pressures over the range 0.1 to 2 mbar. The diagnostics used in the experiments include current derivative, voltage monitor, and plasma image using a ICCD camera gated at 5 ns. The umbrella-like current sheath running over the end of the coaxial electrodes and the pinch after the radial collapse can be clearly observed in the photographs. The velocity of the radial collapse is of the order of 10 5 m/s. The observations are similar to the results obtained with devices operating at energies several order of magnitude higher.

Leopoldo Soto - One of the best experts on this subject based on the ideXlab platform.

  • Electrical Behavior of an Ultralow-Energy Plasma-Focus Device
    IEEE Transactions on Plasma Science, 2014
    Co-Authors: M Barbaglia, Leopoldo Soto, H Bruzzone, Hugo Nestor Acuna, A Clausse
    Abstract:

    Measurements of electrical signals in discharges performed in a miniature plasma-focus device (5 Nf Capacitor bank, central electrode diameter and effective free length 2.0 and 0.5 mm, respectively, no outer electrode) are reported. A lumped model is built that gives good agreement between the model and the recorded signals. The main conclusions are as follows: the voltage at which the chamber disk Capacitor is charged is limited by the gas filling pressure inside the chamber and not just by the voltage in the Capacitor energy source, and the behavior of the discharge current within the vacuum chamber depends on the whole system and not only on the last portion of the circuit, even for longer transmission line lengths.

  • demonstration of neutron production in a table top pinch plasma focus device operating at only tens of joules
    Journal of Physics D, 2008
    Co-Authors: Leopoldo Soto, Patricio Silva, Jose Moreno, Marcelo Zambra, Luis Altamirano, A Clausse, W. Kies, Roberto E Mayer, Cristian Pavez, Luis Huerta
    Abstract:

    Neutron emission from a deuterium plasma pinch generated in a very small plasma focus (6 mm anode diameter) operating at only tens of joules is presented. A maximum current of 50 kA is achieved 140 ns after the beginning of the discharge, when the device is charged at 50 J (160 Nf Capacitor bank, 38 nH, 20–30 kV, 32–72 J). Although the stored energy is very low, the estimated energy density in the plasma and the energy per particle in the plasma are of the same order as in higher energy devices. The dependence of the neutron yield on the filling pressure of deuterium was obtained for discharges with 50 and 67 J stored in the Capacitor bank. Neutrons were measured by means of a system based on a 3He proportional counter in current mode. The average neutron yield for 50 J discharges at 6 mbar was (1.2 ± 0.5) × 104 neutrons per shot, and (3.6 ± 1.6) × 104 for 67 J discharges at 9 mbar. The maximum energy of the neutrons was (2.7 ± 1.8) MeV. Possible applications related to substance detection and others are discussed.

  • Axial and radial measurements of the neutron emission from miniature plasma focus devices
    2004
    Co-Authors: Jose Moreno, Patricio Silva, Leopoldo Soto
    Abstract:

    As first step of a program to design a repetitive pulsed neutron generator for applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Neutron emission has been obtained in both devices operating in deuterium. An especial techniques was necessary to develop in order to detect neutron pulsed of 104 neutrons per shot. The maximum total neutron yield measured was of the order of 106 and 104 neutrons per shot in the PF-400J and PF-50J respectively. Axial and radial measurements of the neutron emission are presented and the anisotropy is evaluated in this work. The neutrons are measured by pairs of silver activation counters, 3He detectors and scintillator-photomultiplier detectors.

  • Hard X-ray sources from miniature plasma focus devices
    2004
    Co-Authors: Verónica Raspa, Patricio Silva, Jose Moreno, Marcelo Zambra, Leopoldo Soto
    Abstract:

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Hard X-rays are being studied in these devices operating in hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400J. An effective energy of the order of 90keV was measured under those conditions. X ray images of different metallic objects also have been obtained.

  • Pinch evidence in a fast and small plasma focus of only tens of joules
    Plasma Sources Science and Technology, 2004
    Co-Authors: Patricio Silva, Leopoldo Soto, W. Kies, Jose Moreno
    Abstract:

    The pinch evidence in a deuterium-filled plasma focus (PF) of only tens of joules is presented. The system operates at a very low energy in the tens of joules range (160 Nf Capacitor bank, 38 nH, 20–35 kV, 32–98 J, ~150 ns current rise time), maintaining the same energy density as in large devices. The typical dip in the current derivative signal and the typical peak in the voltage signal observed in PF devices with energies of 1–1000 kJ, which are associated with pinch compression, were observed in a deuterium-filled PF operating at 50 and 67 J. The time to pinch and time to the peak current versus deuterium filled pressure were also obtained.

Krishna V. Shenoy - One of the best experts on this subject based on the ideXlab platform.

  • Wireless neural recording with single low-powered integrated circuit
    2016
    Co-Authors: Reid R. Harrison, R.j. Kier, Florian Solzbacher, Cynthia A. Chestek, Krishna V. Shenoy, Student Member, Senior Member
    Abstract:

    Abstract—We present benchtop and in vivo experimental results from an integrated circuit designed for wireless implantable neural recording applications. The chip, which was fabricated in a commercially available 0.6- m 2P3M BiCMOS process, contains 100 amplifiers, a 10-bit analog-to-digital converter (ADC), 100 threshold-based spike detectors, and a 902–928 MHz frequency-shift-keying (FSK) transmitter. Neural signals from a selected amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power/command receiving coil and a 100-Nf Capacitor. Index Terms — Brain–machine interface (BMI), low power

  • Wireless Neural Recording With Single Low-Power Integrated Circuit
    IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 2009
    Co-Authors: Reid R. Harrison, R.j. Kier, Bradley Greger, Florian Solzbacher, Cynthia A. Chestek, Vikash Gilja, Paul Nuyujukian, Stephen I. Ryu, Krishna V. Shenoy
    Abstract:

    We present benchtop and in vivo experimental results from an integrated circuit designed for wireless implantable neural recording applications. The chip, which was fabricated in a commercially available 0.6- mum 2P3M BiCMOS process, contains 100 amplifiers, a 10-bit analog-to-digital converter (ADC), 100 threshold-based spike detectors, and a 902-928 MHz frequency-shift-keying (FSK) transmitter. Neural signals from a selected amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power/command receiving coil and a 100-Nf Capacitor.

  • ISCAS - Wireless neural signal acquisition with single low-power integrated circuit
    2008 IEEE International Symposium on Circuits and Systems, 2008
    Co-Authors: Reid R. Harrison, R.j. Kier, Bradley Greger, Florian Solzbacher, Cynthia A. Chestek, Vikash Gilja, Paul Nuyujukian, Stephen I. Ryu, Krishna V. Shenoy
    Abstract:

    We present experimental results from an integrated circuit designed for wireless neural recording applications. The chip, which was fabricated in a 0.6-mum 2P3M BiCMOS process, contains 100 amplifiers and a 10-bit ADC and 902-928 MHz FSK transmitter. Neural signals from one amplifier are sampled by the ADC at 15.7 kSps and telemetered over the FSK wireless data link. Power, clock, and command signals are sent to the chip wirelessly over a 2.765-MHz inductive (coil-to-coil) link. The chip is capable of operating with only two off-chip components: a power receive coil and a 100-Nf Capacitor.

Patricio Silva - One of the best experts on this subject based on the ideXlab platform.

  • demonstration of neutron production in a table top pinch plasma focus device operating at only tens of joules
    Journal of Physics D, 2008
    Co-Authors: Leopoldo Soto, Patricio Silva, Jose Moreno, Marcelo Zambra, Luis Altamirano, A Clausse, W. Kies, Roberto E Mayer, Cristian Pavez, Luis Huerta
    Abstract:

    Neutron emission from a deuterium plasma pinch generated in a very small plasma focus (6 mm anode diameter) operating at only tens of joules is presented. A maximum current of 50 kA is achieved 140 ns after the beginning of the discharge, when the device is charged at 50 J (160 Nf Capacitor bank, 38 nH, 20–30 kV, 32–72 J). Although the stored energy is very low, the estimated energy density in the plasma and the energy per particle in the plasma are of the same order as in higher energy devices. The dependence of the neutron yield on the filling pressure of deuterium was obtained for discharges with 50 and 67 J stored in the Capacitor bank. Neutrons were measured by means of a system based on a 3He proportional counter in current mode. The average neutron yield for 50 J discharges at 6 mbar was (1.2 ± 0.5) × 104 neutrons per shot, and (3.6 ± 1.6) × 104 for 67 J discharges at 9 mbar. The maximum energy of the neutrons was (2.7 ± 1.8) MeV. Possible applications related to substance detection and others are discussed.

  • Axial and radial measurements of the neutron emission from miniature plasma focus devices
    2004
    Co-Authors: Jose Moreno, Patricio Silva, Leopoldo Soto
    Abstract:

    As first step of a program to design a repetitive pulsed neutron generator for applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Neutron emission has been obtained in both devices operating in deuterium. An especial techniques was necessary to develop in order to detect neutron pulsed of 104 neutrons per shot. The maximum total neutron yield measured was of the order of 106 and 104 neutrons per shot in the PF-400J and PF-50J respectively. Axial and radial measurements of the neutron emission are presented and the anisotropy is evaluated in this work. The neutrons are measured by pairs of silver activation counters, 3He detectors and scintillator-photomultiplier detectors.

  • Hard X-ray sources from miniature plasma focus devices
    2004
    Co-Authors: Verónica Raspa, Patricio Silva, Jose Moreno, Marcelo Zambra, Leopoldo Soto
    Abstract:

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications two miniature plasma foci have been designed and constructed at the Comisión Chilena de Energía Nuclear. The devices operate at an energy level of the order of tens of joules (PF-50J, 160 Nf Capacitor bank, 20-35 kV, 32-100 J, ~150 ns time to peak current) and hundred of joules (PF-400J, 880 Nf, 20-35 kV, 176-539 J, ~300 ns time to peak current). Hard X-rays are being studied in these devices operating in hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400J. An effective energy of the order of 90keV was measured under those conditions. X ray images of different metallic objects also have been obtained.

  • Pinch evidence in a fast and small plasma focus of only tens of joules
    Plasma Sources Science and Technology, 2004
    Co-Authors: Patricio Silva, Leopoldo Soto, W. Kies, Jose Moreno
    Abstract:

    The pinch evidence in a deuterium-filled plasma focus (PF) of only tens of joules is presented. The system operates at a very low energy in the tens of joules range (160 Nf Capacitor bank, 38 nH, 20–35 kV, 32–98 J, ~150 ns current rise time), maintaining the same energy density as in large devices. The typical dip in the current derivative signal and the typical peak in the voltage signal observed in PF devices with energies of 1–1000 kJ, which are associated with pinch compression, were observed in a deuterium-filled PF operating at 50 and 67 J. The time to pinch and time to the peak current versus deuterium filled pressure were also obtained.

  • Plasma motion observations in a very small plasma focus in the limit of low energy
    Revista Mexicana De Fisica, 2003
    Co-Authors: Leopoldo Soto, Patricio Silva, Jose Moreno, Luis Altamirano, A Clausse
    Abstract:

    A very small plasma focus device has been designed and constructed. The plasma focus operates in the limit of low energy (160 Nf Capacitor bank, 65 nH, 20 - 40 kV, ∼ 32 - 100 J). The design of the electrode was assisted by a simple model of a Mather plasma focus. A neutron yield of 10 4 - 10 5 is expected when the discharge is operated with deuterium. Experiments in H 2 has been performed at pressures over the range 0.1 to 2 mbar. The diagnostics used in the experiments include current derivative, voltage monitor, and plasma image using a ICCD camera gated at 5 ns. The umbrella-like current sheath running over the end of the coaxial electrodes and the pinch after the radial collapse can be clearly observed in the photographs. The velocity of the radial collapse is of the order of 10 5 m/s. The observations are similar to the results obtained with devices operating at energies several order of magnitude higher.