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Ultra-wideband (UWB) heart-rate monitor designed in this text mainly consists of controller, pulse generator, pulse receiver, and displayer. Controller controls the pulse generating and receiving and heart-rate display. Based on the characteristics of avalanche of RF-BJT, we designed an UWB pulse generator in this paper. By simulating and debugging, we successfully obtained the bipolar UWB pulse, with the peak-to-valley voltage 6.7 V and peak-to-valley width 600 ps. The pulse generating circuit is suitable for the UWB heart-rate monitor, with its simple structure, low cost, and good performance.

To evaluate the current bearing capacity of high voltage direct current transmission (HVDC) converter valve, “DC high-current source" is one of the important device used in the synthesis test system of converter valve, so it is very important to research the control and protection strategies of this DC high-current source. The paper introduces the steady flow control, protection measures, hardware features, software process, etc. The idea of DSP technology, CAN communication technology and embedded six pulse generator triggered technology integrated in the control and protection systems of three-phase full-controlled rectifier bridge is proposed, which forms a complete control and protection system of DC high-current source applied in the synthetic test for converter valve.

In view of the requests of Micro Electric Discharge Machining Pulse Generator, a professional core supporting PWM output based on FPGA has been proposed in this paper. A high precision PWM with frequency and duty adjustable and an interrupt signal which is useful for MCU are produced. The PWM pulse and interrupt output are simulated and analyzed in Quartus II. The PWM pulse duration is up to 10ns. In this paper a 40ns PWM pulse width for MOSFET is realized. It has provided a possible technological assurance for nanofabrication micro-EDM.

Because of low energy transmission efficiency of the transcutaneous coupling power supply device, the factors affecting inefficiency are analyzed and an implantable stimulator external powered is designed. The circuit consists of High-frequency inverter module, transcutaneous transformer and an isolated pulse generator. The circuit realizes that the polarity, amplitude, frequency and pulse width of stimulating pulses are adjustable and controllable. The distance between two transcutaneous coupling coils is the thickness of human skin, usually 5-15mm. Through practical tests at a distance of 10mm, experimental results show that the maximum transmission efficiency is 7.66% at the highfrequency carrier of 300KHz. The variable range of amplitude is between 0 and 10 voltages. The range of frequency is between 100 and 300Hz. So the designed circuit meets the demand of implantable stimulators.

We made a chemical sensor array that detected the concentration of alcohol gas as the degree of synchronization of neural activity. The chemical sensor array consisted of three parts: the chemical sensor, the random pulse generator, and the stochastic synchronizer. The chemical sensor part was commercially available alcohol sensors. The random pulse generator and the stochastic synchronizer parts were implemented in a computer. Outputs of alcohol sensors charged integrate-and-fire cells in the random pulse generator part and caused these cells to fire spikes. These spikes equally converged on a pair of bursting cells in the stochastic synchronizer part and led to the synchronization of their bursting activity. The alcohol gas concentration monotonically increased the frequency of the random pulses and then increased the degree of burst synchronization on the two burst cells. As a result, the concentration of alcohol gas was detected as the degree of burst synchronization.

The purpose of our project is to develop brain-inspired chemical sensor arrays from physiological, theoretical, and engineering points of view. In the previous work, a computational model for chemical sensor arrays has been proposed based on physiological properties of mouse taste bud cells (TBCs). The model consists of three functional parts: the chemical sensor, the random pulse generator, and the stochastic synchronizer. The chemical sensor array based on the computational model detects the concentration of chemical substances as the degree of stochastic synchronization. For practical implementation, we compare the probabilistic firing properties of an array of resonate-and-fire neuron (RFN) models and those of an array of leaky integrate-and-fire neuron models in order to consider their feasibility as the second part of a chemical sensor array. We further investigate stochastic synchronization in uncoupled integrated circuits implementing the RFN model in order to confirm if they act as the third part of a chemical sensor array on a practical hardware platform.

Gas cleaning techniques using non-thermal plasma are slowly introduced into industry nowadays. Here we present a novel power modulator for the efficient generation of large volume corona plasma. No expensive high-voltage components are required. Switching is done at an intermediate voltage level of 1 kV with standard thyristors. Detailed investigations on the modulator and a wire-plate corona reactor will be presented. In a systematic way, modulator parameters have been varied. Also reactor parameters, as the number of electrodes and the electrode-plate distance have been varied systematically. The yield of O-radicals was determined from the measured ozone concentrations at the exhaust of the reactor.

The aim of this paper is to develop a programmable and implantable neuro-stimulator for animal research and clinical application. The neuro-stimulator includes implantable pulse generator, extension (if necessary) and lead implanted in the body, and controller, PDA and magnet used outside the body for telemetry/programming. It provides electrical pulse stimulation to the target nerve or brain nucleus, with adjustable pulse parameters of pulse width, frequency, amplitude, on time and off time. The ultra-low power consumption circuit based micro-processor was developed, and welded with primary lithium battery, then were sealed by titanium case and feedthroughs hermetically using laser welding. The implantable pulse generator has the weight of about 34 g, the size less than 47*52*11 mm, and two kinds of circuit can be installed in it, i.e. current pulse control for nerve stimulation and voltage pulse control for brain stimulation. The pulse parameters of amplitude, pulse width, frequency and electrode configuration can be programmed by controller and PDA, e.g. pulse amplitude is 0–10V in 0.05V or 0.1V steps for voltage pulse control, 0–3.5mA in 0.1mA steps for current voltage pulse control. The neuro-stimulator has been validated the safety and function during long-term implantation by animal experiments of vagus nerve stimulation (VNS) using 20 rabbits and deep brain stimulation (DBS) using 1 rabbit, and DBS experiments for PD treatment using rhesus monkey is in process. The developed neuro-stimulator can be used in clinical application of DBS, VNS and other brain/nerve stimulation, and also an instrument platform for animal experiment research of implantable neuro-stimulation to study therapy mechanism and optimized stimulation parameters.

We have proposed a force perception method based on asymmetric oscillation that exploits the characteristics of human perception. Our previous findings indicate that the pulse frequency determines the effective generation of the kinesthetic illusion of being pulled. However, whether pulse frequency or pulse width for force perception has not been clarified. If the pulse width is more dominant, the force sensation induced by sequential pulses will be more continuous. This is important because many of those who have experienced the asymmetric oscillation pointed out that the force sensation induced by the stimuli was not felt smoothly compared to physical force. This paper describes the design and development of a new multicylinder-like mechanism for generating sequential pulses, which should enable us to determine which is dominant for force perception.

Fatty acids and cholesterol are important substances for the living matter, especially for the biological membrane [1]. Since the liquid crystal state of these substances can give information on some membrane mechanism [2], their answer to some external stimuli within the mesomorphism interval has been widely studied. The possibility of inducing a non-linearity in such systems could lead to a radical change of their dynamics. Interesting non-linear optical laser based answers were obtained in different thin film samples. We analyzed these effect answers and the measurement procedures. For simulating the generation of delayed pulses inside organic mixtures a mathematical model based on practical test-functions has been used. The input pulse (usually represented by an optical or electromagnetic pulse) generates a delayed pulse inside the material medium, and thus a modulated input pulse represented by a gaussian function modulated by a sine function has been used for simulation, with good results.

In this paper, we represented performance of UWB system and designed UWB system using proposed pulses in [1] that are strictly limited in time to remove interference while, at the same time, contain their power distribution to a frequency band from 3.1 GHz to 10.6 GHz. In particular, we evaluated the BER Performance in relation to system parameters such as pulse duration, d, the number of users, Nu, and the number of symbols, M. We designed UWB pulse generator using advanced Samsung CMOS technology. We confirmed that the full chip is operated by completed UWB signal. These results can be contributed to construct M-ary PPM UWB communication system under location based services environments

We have developed a high-pressure pulse generator at a high repetitive rate by combining a diaphragmless shock tube with shock strengthening by area convergence. The diaphragmless shock tube generates shock waves with Mach numbers of up to 2 traveling in the tube at atmospheric pressure. The shock waves are accelerated by reducing the cross sectional area of the tube. The maximum pressure at the tube end, where the cross sectional area was reduced to 1/64 from the original, exceeded 10MPa and the pulse width was about 25 μ sec. These pressure pulses were generated at a rate of one pulse per several seconds. The facility was used to study biomechanical and biological effects of high-pressure pulses on microorganisms and DNA.

During the past 35 years, many technological advantages have been made in cardiac pacemaker leads and in the pulse generator-to-lead connector. Advances have included development of: various coiled wire conductors [1]; new fixation means such as tines, fins, and helix mechanisms [1,2]; advances in electrodes such as microporous surfaced electrodes, small surface area electrodes, electrodes with special shapes which enhance electrical fields and tissue ingrowth and steroid eluting electrodes [3, 4]; improved insultion such as “high-performance” or “extra tear-resistant” silicone rubbers, and various polyurethanes [5]; and improved, standardized connectors such as the recent “VS-1” and proposed “IS-1” standard connector designs [6]. These advances have improved the performance, reliability, and the ease of implantation of pacemaker leads and pulse generators dramatically. Perhaps however, historically, one of the most significant advances in pacemaking was the development of the transvenous pacemaker lead which made the therapy of cardiac pacing a relatively safe and easy procedure for virtually all patients [7].

Circuits for generation picosecond step and pulse signals have many applications in wide bandwidth time-domain and microwave instrumentation. The silicon step-recovery diode is widely used in sampling oscilloscopes and network analyzers for gating sampling diodes but has limited utility in optoelectronic and ultrafast applications due to its relatively slow speed (30–40 ps). Conversely, photodiodes and photoconductors produce much narrower electrical pulses [1,2] but the real pulse generator is a femtosecond or picosecond mode-locked laser. Using only RF drive, we have measured a 6 V, 1.8 ps falltime step output as well as a 2.4 V, 4.4 ps full width at half maximum (FWHM) pulse output from monolithic GaAs nonlinear transmission line (NLTL) circuits.

The measurement of diastolic stimulation threshold at pacemaker implantation is a necessary prerequisite for the verification of an optimally longterm functioning of implanted pulse generator systems (34). Thereby, the initially measured threshold energy can be primarily seen as an expression of optimal electrode positioning and a technically flawless system of impulse transmission by the pacemaker electrode. Measurements dealing with improved pacemaker electrode technology presuppose a homogeneous group of patients. A uniform basis for the evaluation of later developing pacemaker stimulatory threshold can only be obtained if physiological, patho-physiological and pharmacological conditions are kept constant. On a short-term basis, conditions can be kept constant, usually without difficulty, in order to observe the influences of the individual factors. Long-term continuous observations must on principle be able to differentiate between a summation of factors at implantation and later measurements.

Improving reliability and longevity of pacemaker power sources has emphasized the growing need for standardized evaluation of pacemaker pulse generators and their power supplies. We present here our versions of two statistical methods for such evaluation.

Picosecond electrical pulses with well resolved frequency components into the terahertz region are ideally suited for the characterization of VLSI electronics, both for the devices themselves and for the interconnect wiring. In this paper, we describe the technology we employ to photoconductively generate and measure these ultrafast electrical signals./1/ A particular emphasis was given to the compatibility with existing VLSI device technology. Although other measurement techniques /2,3/ have shown very good sensitivity and time resolution, the photoconductive sampling technique is particularly attractive for silicon device characterization with a comparable sensitivity and time resolution /4/ and a better amplitude calibration and reproducibility as the sampling geometry is defined by the lithography itself. Impedance matching is facilitated while keeping identical geometries between the device site and the generating and sampling sites. We also present results on the optoelectronic characterization of a 1μm gate GaAs MESFET. We will not address in this paper the problem of circuit testing which has some stringent additional requirements, in particular that of submicron spatial resolution and of wide field addressing capability. These imperatives may ultimately limit the use of purely optical techniques for the functional testing of high speed circuits at their internal nodes.

The whole stimulation system consists of three parts: the pulse generator, the myocardium and the electrodes.

The major thrust in prolonging the longevity of pacemakers has been directed at the power source. Improvements in manufacture and in the design of the circuit and electrodes have, until now, been of secondary importance.

The generation of short electrical pulses via optical methods has for some time been performed by driving Auston switches (photoconductive gaps) with short laser pulses.[l] The shape of the electrical pulse depends on the laser pulseshape, the material properties of the semiconductor, the nature of the charge source, and the characteristics of the associated electrical transmission line. The same techniques can also measure the generated electrical pulses by sampling methods. An alternate measurement approach has been to use the electro-optic effect in a crystal.[2] In this case, the field of the electrical pulse is sampled through the rotation of the polarization of the optical sampling pulse. Because it has demonstrated 460 fsec time resolution,[3] the electro-optic method is presently considered to be the fastest sampling technique. However, recent work utilizing photoconductive switches has generated and measured subpicosecond electrical pulses.[4] This large reduction in the generated pulsewidth demonstrates the ultrafast capability of the Auston switches and challenges the ultrafast time resolution of the electro-optic methods. We will now discuss subpicosecond pulse generation using photoconductive gaps,[4] together with the initial interpretation of these experimental results. In addition, we will present some recent measurements, which will allow us to conclude with a relatively complete description of the pulse generation process.

Right ventricular, high speed electrograms were taken during 59 transvenous pacemaker implants (acute cases) and 37 pulse generator replacements (chronic cases, after the electrode had been in service at least 6 months and as long as 5 years). The morphology, peak-to-peak voltage swing, apparent ST displacement, maximum slew rate, stimulation current threshold, and electrode surface area were recorded and compared.

The maturing of the semiconductor industry has resulted in the need for faster methods for the measurement of pulse waveforms. The measurement requirements are fast outstripping the capability of integrated circuit testors. The fastest commercial sampling oscilloscope today has a step response transition duration (risetime) of 20 picoseconds. For the measurement of single transients, available time resolution is somewhat less. This time resolution is not adequate to support the measurement of the faster semiconductor devices being developed, such as gallium arsenide logic gates whose switching times have been estimated to be 12 picoseconds [1]. Measurement of such transitions requires a significant advance in measurement technology. A prime candidate for making the required quantum leap in time measurement resolution is the electro-optic sampler [2]. This sampler has a demonstrated resolution of 0.4 picoseconds and a theoretical resolution limit much shorter than that.

High voltage pulse forming techniques, utilizing spark gaps, is a mature field. However, problems associated with synchronizing spark gap switching, in the picosecond regime, limit its application. A new approach, developed over the past few years, is to use laser controlled photoconductive switches in generating ultrashort high voltage pulses.1 The use of photoconductive switches achieves picosecond synchronization and very long lifetimes. Furthermore such switches can be readily incorporated into various types of pulse generating and forming structures. We report here on an investigation of the performance of various types of high voltage generating structures with photoconductive switches. These include Blumleins (with multiple switches), Marx banks, stacked lines and L.C. generators in coaxial, microstrip and coplanar geometries. High voltage pulses with picosecond rise and fall times were generated and monitored using Pockels cells monolithically integrated with the pulse forming structures. Using dc charged voltage multiplication circuits, up to 5 kv was generated in nanosecond pulses. Also, 5 kv of peak to peak RF single cycle pulses were generated using a similar multiplication circuit. This type of RF pulses have important applications in high resolution radar systems.2

Picosecond optoelectronics provides the capability to measure the frequency response of solid state devices with much greater bandwidth than conventional techniques. Laser-triggered switches acted as pulse generators and samplers to measure the impulse response of a device with a temporal resolution of a few picoseconds. Fourier analysis of the impulse response functions yields scattering matrix parameters with a frequency bandwidth of 40 GHz or more. In comparison, current frequency-domain technology is limited to a 26 GHz bandwidth. (Higher frequencies can be covered with frequency mixing techniques, at the cost of additional noise and experimental complexity.)

In a recently described measurement scheme [1], the picosecond photoresponses of two radiation-damaged photoconductors were correlated by using these detectors as Hertzian dipoles, i.e., radiating and receiving dipole antennas. As in earlier microstrip circuit correlation experiments [2], one photoconductor is DC biased and acts as an electromagnetic pulse generator in response to excitation by a short optical pulse. The second photoconductor is biased by the electromagnetic transient from the first photoconductor, and functions as a sampling gate when excited by a second, delayed optical pulse. By monitoring the current induced in the circuit of the second photoconductor as a function of the delay between the optical pulses, the correlated photoresponse of the two circuits is measured. In Hertzian dipole experiments, a transient electromagnetic pulse from the pulse generator is radiated freely through a bulk dielectric to the second, receiving photoconductor. This results in a high pass coupling scheme, as opposed to the low pass transfer characteristics of microstrip interconnections.