Trigger Device Research Articles

Acoustic instrument triggering device and method

An acoustic instrument triggering device has a body portion that may be mounted on an acoustic instrument, such as, for example, a drum. An arm extends from the body portion. A sensor, which includes, a transducer, is disposed in the arm and is adjustable so that the cushion portion makes contact with a drum head or other vibrating portion of the instrument. A cushion portion transfers vibrations to the transducing element, which in turn transduces the vibrations into electrical signals that can be processed to form an audio signal or used to trigger other devices.

Compact monochromatic flash x‐ray generator utilizing a disk‐cathode molybdenum tube

The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum Kalpha lines are produced using a 20 microm-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of Kalpha photons was approximately 3 x 10(7) photons/cm2 per pulse at 0.5 m from the source of 3.0 mm in diameter.

Quasi-Monochromatic Flash X-Ray Generator Utilizing Disk-Cathode Molybdenum Tube

High-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -40 to -60 kV using a power supply, and the electric charges in the condensers are discharged to an X-ray tube after closing the gap switches in the surge generator using a trigger device. The X-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Sharp K-series characteristic X-rays of molybdenum are produced without using a monochromatic filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. The peak tube voltage increased with increasing charging voltage and increasing space between the target and cathode electrodes. At a charging voltage of -60 kV and a target-cathode space of 1.0 mm, the peak tube voltage and current were 110 kV and 0.75 kA, respectively. The pulse width ranged from 40 to 100 ns, and the maximum dimension of the X-ray source was 3.0 mm in diameter. The number of generator-produced K photons was approximately 7×1014 photons/cm2·s at 0.5 m from the source.

Bunched beam test of the CMS drift tubes local muon trigger

The 40 MHz bunched muon beam set up at CERN was used in May 2003 to make a full test of the drift tubes local muon trigger. The main goal of the test was to prove that the integration of the various devices located on a muon chamber was adequately done both on the hardware and software side of the system. Furthermore the test provided complete information about the general performance of the trigger algorithms in terms of efficiency and noise. Data were collected with the default configuration of the trigger devices and with several alternative configurations at various angles of incidence of the beam. Tests on noise suppression and di-muon trigger capability were performed.

Masseter reflex in childhood and adolescence

We report normative data of masseter reflex from a group of 54 children 2-16 years of age. For statistical analysis, the patients were divided into five age groups: 2-4, 5-7, 8-10, 11-13, and 14-16 years of age. A tap to the chin, using a hammer with a trigger device, elicited the masseter reflex. The response was recorded by surface electrodes. The onset latency and peak-to-peak amplitude of the averaged curve of eight reflex responses were measured. The reflex response could be recorded in all children and adolescents of all groups. The mean latency shortened from age 2 to 7 and was stable at the age of 8 years. As a sign of maturation, the increase of amplitude corresponded to the shortening of latency and was also stable at the age of 8 years. Abnormal side differences in latency of 0.9 ms (age group 2-4 years), 1.1 ms (age group 5-7 years), and 0.8 ms (age group 8-16 years) were evaluated. An amplitude ratio (lower amplitude divided by higher one) above 0.33 was calculated as normal.

Developments of Enediyne Model Compounds Generating Biradicals with an Enhanced Radical Character – Regulation of Triggering Devices

Development of enediyne model compounds generating biradicals with an enhanced radical character is described. These model compounds generate enyne-allenes under mild acidic conditions and the resulting biradicals showed potent DNA cleaving abilities.

Studies of the human oropharyngeal airspaces using magnetic resonance imaging. I. Validation of a three-dimensional MRI method for producing ex vivo virtual and physical casts of the oropharyngeal airways during inspiration.

The oropharyngeal region of the human airways has been scanned using 3D MRI and the data used to produce a model cast. The scanning method used a triggering device, which enabled data collection at the same pressure drop in each breathing cycle to produce clear images free of motion-related artefacts. A comparison between two differing MR acquisition strategies was made in a single subject, multi-session study. 3D FISP MR imaging was found to produce the most reliable data. Excluding the buccal cavity, where tongue position was critical, the reproducibility of measured airway volumes and cross sectional areas between sessions was demonstrated. Inter-session total airway volume (excluding the mouth) reproducibility was of the order of 5% and for minimum cross sectional areas at the epiglottis and vocal cords was 10%. The production of a physical cast from the images led to a 5% increase in airway volume compared with the anatomical images but with some loss of fine detail. The data demonstrated the robustness of an ex-vivo means of studying oropharyngeal dimensions and dynamics which may contribute to advancements in the understanding of aerosol delivery of therapeutic agents.

Topographic Mapping of Retinal Function with the SLO-mfERG under Simultaneous Control of Fixation in Best’s Disease

Purpose: To introduce the scanning laser ophthalmoscope-evoked mfERG (SLO-mfERG) as a new method to measure focal retinal function. Methods: Sixty-two healthy individuals and 12 patients with Best’s disease were examined. mfERGs were recorded using a scanning laser ophthalmoscope as a stimulator and trigger device (He-Neon 632.8 nm) as well as a fundus-monitoring system (Infrared 730 nm). Results: Amplitudes in the central concentric area were found to be significantly lower in patients with Best’s disease than in healthy controls, while no significant differences were found for the more peripheral areas. Conclusion: SLO-mfERG is a reliable new technique for topographic mapping of retinal function under simultaneous control of fixation.

Simultaneous recording of blood pressure and ST-segment with combined, triggered ambulatory 24-h devices.

Silent myocardial ischemia is defined as an ischemic episode without chest pain but with transient ST abnormalities during stress testing or Holter monitoring. With Holter monitoring the prevalence of silent myocardial ischemia in hypertensive patients without coronary artery disease is between 25% and 73%. Simultaneous recording of ambulatory 24-h ECG and 24-h ambulatory blood pressure measurements (ABPM) with the option of additional ST-triggered blood pressure measurement is useful to detect silent ischemia and triggers of silent ischaemia. It is surprising that only a few combined 24-h Holter/ABPM devices are on the market, and in turn only three devices allow additional triggered blood pressure measurements. The paper provides an overview of studies investigating hypertensive patients with Holter monitoring for the detection of ST segment depression indicating myocardial ischaemia. Furthermore, requirements for combined devices allowing simultaneous ambulatory 24-h ECG and ABPM are defined.

Synthesis of enediyne model compounds possessing a cyanohydrin moiety as a triggering device

Development of enediyne model compounds possessing a cyanohydrin moiety is described. These model compounds generate enyne–allenylketones efficiently under mild basic conditions and the resulting biradicals showed potent DNA cleaving abilities.

Platonic Relations

Platonic Relations

Matching approved "nondedicated" hardware to obtain biventricular pacing and defibrillation: feasibility and troubleshooting.

Biventricular ICDs may offer increased benefit for patients with severe congestive heart failure and ventricular arrhythmia. Currently there are no approved dedicated biventricular ICDs available. Twenty-one consecutive patients who had approved nondedicated hardware implanted for biventricular pacing and defibrillation were included in this study. All device therapies were evaluated using stored electrograms. During mean follow-up at 13 +/- 7 months, 8 (36%) patients had inappropriate shocks. Ventricular fibrillation therapy was delivered for slow ventricular tachycardia because of double counting in two patients. In one patient, AV nodal reentrant tachycardia below detection rate cut off triggered device therapy because of ventricular double counting. Sinus tachycardia or premature atrial contraction initiating AV conduction and ventricular double counting resulted in shocks in five patients. The number of shocks per patient ranged from 1 to 64. Two patients required transient disconnection of the LV lead and subsequent ICD generator replacement for premature battery depletion. Two patients required AV junction ablation and three needed slow pathway ablation. Two patients were treated by upgrading to a device that was capable of a higher atrial tracking rate. The patients with impaired AV conduction or constant ventricular pacing did not have inappropriate therapy for sinus tachycardia or supraventricular arrhythmia. Use of conventional nondedicated hardware for biventricular pacer/defibrillator is feasible but should be considered only in patients with poor AV node function or less likely to require antitachycardic therapy, to avoid ICD double counting of ventricular sensed events and consequent high incidence of inappropriate therapies.

Silicon germanium heterojunction bipolar transistor electrostatic discharge power clamps and the Johnson Limit in RF BICMOS SiGe technology

Achieving radio frequency (RF) performance circuit objectives and electrostatic discharge (ESD) protection will continue to challenge future technology. In this study, we use the ultimate limitation of the transistor (known as the Johnson Limit) as a means to provide an ESD power clamp by utilizing a first low breakdown trigger device and a second high breakdown clamp device. Using the inverse relationship between unity current gain cutoff frequency and breakdown voltage, ESD power clamps are constructed using epitaxial base pseudomorphic silicon germanium (SiGe) heterojunction bipolar transistors in a common-collector Darlington configuration. ESD experimental test results from human body model (HBM), machine model (MM) and transmission line pulse (TLP) testing demonstrate the scaling of ESD power clamps. Design studies of alternative implementations, resistor ballasting and different trigger transistors will be discussed. As a comparative analysis, the SiGe-based ESD power clamps will be compared to CMOS MOSFET-based ESD power clamps. A new dimensionless group is defined to quantify the relationship between the power-to-failure and the maximum power. Additionally, a future SiGe technology is shown to provide insight into the impact of technology scaling on future SiGe ESD power clamps.

4D-MRI using the synchronized sampling method (SSM)

A synchronized sampling method (SSM) was developed for the study of voluntary movements by combining the electrocardiographic (ECG) gating method with an external triggering device, and four-dimensional magnetic resonance imaging (4D-MRI) at a rate of 30 frames per second was accomplished by volumetric imaging with the SSM. This method was first applied to the motion imaging of articulatory organs during repetitions of a Japanese five-vowel sequence, and the dynamic change in vocal tract area function was demonstrated with sufficient temporal resolution. This paper describes the methodology, applicability, and limitations of 4D-MRI with the SSM.

Analytical Formulation of (0°, ± α°) Braided Composites and Its Application In Crashworthiness Simulations

New types of tridimensional composite materials have been developed during the last few years. These new materials consist of braided, weft or warp knitted, and 3D woven composites preforms, and they present excellent out-of-plane mechanical properties. In this article, tubular energy absorbers, constituted of carbon-glass hybrid braided composites, are analyzed by means of the finite-element method, with explicit time integration of the equations of motion. A new material model for (0°, - f °) braided composites is introduced in a commercial finite-element code by means of user-developed subroutines. Braided materials with carbon fiber in the 0° direction and glass fibers in the - f ° directions are studied. Moreover, different fiber orientations and geometry of the triggering devices are analyzed in order to obtain the optimum configuration in terms of specific energy absorption.

Analytical Formulation of (0°, ± α°) Braided Composites and Its Application In Crashworthiness Simulations

New types of tridimensional composite materials have been developed during the last few years. These new materials consist of braided, weft or warp knitted, and 3D woven composites preforms, and they present excellent out-of-plane mechanical properties. In this article, tubular energy absorbers, constituted of carbon-glass hybrid braided composites, are analyzed by means of the finite-element method, with explicit time integration of the equations of motion. A new material model for (0°, - f °) braided composites is introduced in a commercial finite-element code by means of user-developed subroutines. Braided materials with carbon fiber in the 0° direction and glass fibers in the - f ° directions are studied. Moreover, different fiber orientations and geometry of the triggering devices are analyzed in order to obtain the optimum configuration in terms of specific energy absorption.

Optimization of a vacuum spark discharge for soft-X-ray emission

A 1-kJ vacuum-spark device has been developed as a pulsed X-ray source for applications in the field of microlithography, microscopy, flash radiography, etc. The optimization works for the pulsed soft-X-ray emission are presented. The optimization was made in two steps: 1) X-ray emission maximization and 2) X-ray emission reproducibility. For the X-ray emission maximization, the changed parameters were the main capacitor energy, the anode-cathode geometry, the anode material, and the trigger pulse amplitude. The best combination is 1 kJ for the main capacitor energy, a conical shape for the anode, 6-12 mm anode-cathode separation, iron for the anode material, and 14-15 kV for the trigger pulse amplitude. In these conditions, energies of up to 10 J per pulse are obtained in the 3-40 keV range for the X-ray pulses. In order to have a good reproducibility, a high-power, very fast, high-voltage trigger pulse is required. To fulfill these conditions, a pulse transformer and an air spark gap were added to the initial triggering device (a magnetic pulse compression circuit). With the new trigger pulse (20 J per pulse, 50-ns rise-time, 22-kV amplitude in an open circuit), an acceptable X-ray emission reproducibility was obtained.

A New Instrument for Measurement of the Solar Aureole Radiance Distribution from Unstable Platforms

A novel imaging solar aureole radiometer, which can obtain absolute radiometric measurements of the solar aureole when operated on an unstable platform, is described. A CCD array is used to image the aureole, while a neutral density occulter on a long pole blocks the direct solar radiation. This ensures accurate direction registration as the sun appears in acquired images, and the total circumsolar region is measured simultaneously. The imaging nature of this instrument along with a special triggering device permit acquisition of the circumsolar sky radiance within 7.5° of the center of the solar disk, and within 1° of the edge of the solar disk. This innovation makes possible, for the first time, reliable and accurate radiometric measurements of the solar aureole from unstable mobile platforms such as ships. This allows determination of the small angle atmospheric light scattering. The instrument has been used in field studies of atmospheric aerosols and will be used in satellite validation and calibration campaigns.

Flow cytometry and integrated imaging

It is a serious problem to relate the results of a flow cytometric analysis of a marine sample to different species. Images of particles selectively triggered by the flow cytometric analysis and picked out from the flowing stream give a valuable additional information on the analyzed organisms. The technical principles and problems of triggered imaging in flow are discussed, as well as the positioning of the particles in the plane of focus, freezing the motion of the quickly moving objects and what kinds of light sources are suitable for pulsed illumination. The images have to be stored either by film or electronically. The features of camera targets and the memory requirements for storing the image data and the conditions for the triggering device are shown. A brief explanation of the features of three realized flow cytometric imaging (FCI) systems is given: the Macro Flow Planktometer built within the EUROMAR MAROPT project, the Imaging Module of the European Plankton Analysis System, supported by the MAST II EurOPA project and the most recently developed FLUVO VI universal flow cytometer including HBO 100- and laser excitation for fluorescence and scatter, Coulter sizing as well as bright field and and phase contrast FCI.

The HADES RICH detector

A fast RICH will act as a hadron blind trigger device in the high-resolution di-electron spectrometer HADES. The goal is to identify e + e − pairs from meson decays produced in hadron and heavy-ion induced collisions at a few GeV/nucleon incident energy. Concept and expected performance of the RICH utilizing a C 4 F 10 -radiator and a gaseous photon detector with CsI-converter are discussed. Preliminary results of a first in-beam measurement are presented.