558 results about "Nanosecond pulse" patented technology

A method and apparatus are provided for delivering an agent into a cell through the application of nanosecond pulse electric fields (“nsPEF's”). The method includes circuitry for delivery of an agent into a cell via known methods followed by the application of nanosecond pulse electric fields to said cell in order to facilitate entry of the agent into the nucleus of the cell. In a preferred embodiment, the present invention is directed to a method of enhancing gene expression in a cell comprising the application of nanosecond pulse electric fields to said cell. An apparatus for generating long and short pulses according to the present invention is also provided. The apparatus includes a pulse generator capable of producing a first pulse having a long duration and low voltage amplitude and a second pulse having a short duration and high voltage amplitude.

A laser system capable of efficient production of high energy sub-nanosecond pulses in the 2-15 μm spectral region is disclosed. Diode pumped solid state lasers are used as pump sources. The system design is simple, reliable and compact allowing for easy integration. The laser system includes a combination of compact solid-state ˜1 micron laser sources, producing high power picosecond pulses, with optical parametric amplification and a quasi-continuous wave laser for seeding the amplification process that enables the efficient conversion of the high power ˜1 micron laser radiation to tuneable mid-infrared sub-ns pulses. New parametric processes are presented for achieving high gains in bulk nonlinear crystals. Furthermore, a method of exceeding the fundamental conversion efficiency limit of direct three wave mixing is presented. The compact and robust nature of this novel laser system opens up the use of high power and high peak power mid-infrared laser pulses to a wide variety of important medical and dental applications.

Systems and methods for treating tumors on or within internal organs of mammals that have been imaged with endoscopic ultrasound are described. The system uses an expandable bipolar electrode assembly that can be imaged by ultrasound and can penetrate, e.g., the stomach, intestine or bowel wall, etc. and be positioned in or around the tumor on an internal organ while being guided by an operator who visualizes its position with ultrasound imaging. It utilizes an electrode assembly that extends down an internal cavity in the endoscope to allow the operator to spread the electrodes for pulse delivery of a nanosecond pulsed electric field (nsPEF) to the tumor.

The invention relates to an experimental apparatus for acquiring large-area uniform discharge plasmas, which belongs to the technical field of plasmas. The experimental apparatus comprises a bipolar nanosecond pulse power supply, a reactor, multi-needle-to-plate electrodes, a gas distribution system, a spectral measurement system and a discharge measurement system, wherein the bipolar nanosecond pulse power supply drives dielectric barrier discharge of air and other gas mixtures among the multi-needle-to-plate electrodes in the reactor, and the gas mixtures are input to the reactor through the gas distribution system; the spectral measurement system collects photonic information of plasma discharge in real time and inputs the photonic information to a computer for spectral analysis; and the discharge measurement system collects discharge voltage and current of the high-voltage nanosecond pulse power supply in real time, and the discharge voltage and current are displayed through a digital oscilloscope. By virtue of the bipolar nanosecond narrow-pulse power supply, the large-area discharge plasmas are generated without a magnetic field; and the generated plasmas are uniform, diffusive, high in electron density, high in energy utilization ratio, low in energy consumption and easy to control in a discharge process.

This invention relates to a pulse generator circuit for delivering a short high current pulse to a load. This pulse generator comprises a junction recovery diode, a switch, a first resonant circuit and a second resonant circuit. The diode may be configured to store charges in its depletion layer when there is a forward flow of a current and to rapidly switch open after the depletion layer is discharged by a reverse flow of a current. After the diode rapidly switch opens, the pulse generator may provide a reverse current to the load. This pulse generator may be configured to generate at least one pulse that is having a length of no more than 100 nanoseconds at the full-width-at-half-maximum and an amplitude of at least 1 kilovolt. Electrodes may be connected to the pulse generator to deliver one pulse or plurality of pulses to biological cells such as tumor cells.

The invention belongs to the technical field of the power supply, in particular to an all solid state high voltage nanosecond pulse power supply. The power supply is divided into the following two parts: a series voltage booster circuit and a pulse compression circuit, wherein the series voltage booster circuit consists of a series of voltage units which are connected in series to realize the function of voltage boost; each voltage unit is provided with a capacitor connected with a switch which can be connected and disconnected, and capacitors of the series of the voltage units form a capacitor unit; one part in the switch is a charge switch to charge the capacitors in parallel, while the other part is a discharge switch to discharge the capacitors in series; the pulse compression circuit is connected with a magnetic switch in a series connection mode by an energy storage capacitor or a sharpening capacitor. The power supply reduces system volume to connect more voltage units in series, and uses a direct current charge power supply with lower voltage to charge a pulse generator; the adopted switch device generator has longer service life and higher frequency; and the used magnetic switch reduces rise time of voltage pulse output by a Marx circuit, and is free of maintenance and has low failure rate.

The invention relates to an ultra-high frequency positioning and detection device of local discharge of electrical equipment and a method thereof, belonging to the technical field of experiments of local discharge of the electrical equipment. The device comprises a steep-sided pulse generator, an ultra-high frequency antenna, a high frequency coaxial cable and a high sampling rate oscilloscope. The device is characterized in that the steep-sided pulse generator is a nanosecond pulse generator. The method performs the positioning computation by using the device and a computer through a program and a positioning principle based on the time difference method. The device has simple connection; nanosecond pulse signals generated by the steep-sided pulse generator can really simulate ultra-high frequency signals of the local discharge of the electrical equipment and have strong interference resistance and high accuracy of read time different signals, thereby improving the positioning accuracy. The invention can be widely applied to the experiment of the ultra-high frequency positioning detection of the local discharge of the electrical equipment.

The invention discloses a laser capable of simultaneously outputting nanosecond pulses and pico-second pulses. The laser comprises a signal source, a signal isolation system and an amplifier. According to the invention, with an electric light control technology of combining an extra-cavity Pockels cell and intra-cavity Pockels cell, a regenerative amplification process is realized in case of signal light importing so as to obtain high-energy pico-second laser output, and cavity empty process is also realized in case of no signal light importing so as to obtain nanosecond pulse output; and thefree combination of the two processes can be realized according to practical application demand, and as a result, free combination of numbers of the nanosecond pulses and the pico-second pulses in a single laser is realized and is output in an alternative way. The laser provided by the invention has an important application in high-precision high-efficiency fine processing field, as well as basicresearch fields such as plasma excitation, excited state control, chemical reaction control, special radiation excitation and the like.

A time-resolved fluorescence device is described for the detection and diagnosis of various metabolic diseases in a noninvasive or minimally invasive manner. The device uses an ultra-short excitation pulse that comprises of a repetition of nanosecond pulses. The excitation pulse is directed incident onto a strategically selected area of the patient body such as the forearm, the feet, and the palm. This light interacts with the different layers of the skin. The absorbed light excites conditions of interest in the skin, which in turn generate a fluorescence signal, which is collected by a detector. A processor is coupled to the detector to measure the transient fluorescence intensity decay of the skin in terms of lifetimes, and the contribution of individual fluorophores to the overall fluorescence signal.

The invention relates to an annular discharge based transient state plasma igniter. An insulation sleeve is located in an insulation protection sleeve, and one end of the insulation sleeve is located in a cathode. An anode conduction rod is located in the insulation sleeve, and one end of the anode conduction rod is arranged in a center hole of the cathode. One end of the insulation protection sleeve is arranged in a fixing base. The anode is located in the cathode. The transient state plasma igniter is provided with a mixed gas channel. According to the invention, high-energy nanosecond pulse is used to discharge electricity to form a local high temperature area, and a large quantity of active particles are activated to ignite combustible mixed gas in an extremely short period of time. The ignition area is large, and the mixed gas can be ignited by multiple points; the ignition time is extremely short, and the ignition delay time is shorter; the ignition energy can be well coupled with the gas mixture, macromolecule hydrocarbon fuel in the ignition area is ionized as active particles with low activation energy, so that the chemical reaction of the mixed gas is faster, the reaction time is shorter, and the ignition success rate is high.

The invention relates to a nano-femtosecond dual-laser composite machining system. The system comprises a femtosecond laser, a nanosecond laser, a synchronous control circuit, an illuminating light source, a semi-transparent semi-reflecting mirror, a first dichroscope, a second dichroscope, a focusing lens and a charge coupled device (CCD) image detector, wherein the synchronous control circuit controls laser pulse output of the femtosecond laser and the nanosecond laser, and accurately adjusts relative time of nanosecond pulse and femtosecond pulse in the aspect of time to synchronize leading edges of the two pulses; the illuminating light source is positioned on one side of the semi-transparent semi-reflecting mirror, and the second dichroscope, the first dichroscope and the focusing lens are coaxially arranged on the other side of the semi-transparent semi-reflecting mirror in turn and are positioned on a straight line together with the illuminating light source; and the CCD image detector is positioned at the tail end of a reflecting light path of the semi-transparent semi-reflecting mirror. Through the system, the advantages of high femtosecond laser machining accuracy and high nanosecond laser machining efficiency are simultaneously integrated, and high-accuracy and high-efficiency micro-nano machining is realized; and the system can be widely applied to the fields such as high-accuracy machining of aviation and aerospace key parts, microstructure machining of a laser fusion ignition target, microstructure machining of a microsensor and the like.

A device for inducing apoptosis of tumor cell with high voltage nanosecond pulse belongs to technology field of electric impulse for treatment of tumor. The inventive device mainly comprises high voltage direct current module, pulse formation system, pulse measurement system, computer system, and power system. Amplitude value of high voltage nanosecond pulse is continuously regulated or preset between 0-9.9kV, repetition frequency is continuously regulated or preset between 2-100Hz, width is continuously regulated or preset between 200ns-1 mu s by separating to 7 grades, and numbers is regulated or preset according to treatment requirement. As the inventive device can induce apoptosis of tumor cell, is an unalloyed physical method, has no requirement of medicament assistance, thus can completely avoid toxic and adverse side effect of chemotherapeutics during treatment and adverse reaction such as inflammation, pain, ulcer and stammer, therefore the inventive device can be widely used in oncotherapy and treatment of removing polypus and redundant grease and vulvopathy.

A plastic micro-forming method by using strong laser shock and a device thereof belong to the field of micro-electro-mechanical system (MEMS) processing and laser micro-processing technology. The method is characterized in that the method comprises the following steps: polishing both sides of a target for experiment by electrolysis; pressing a transparent optical medium with a thickness of micrometer level on a press plate as a constrained layer; tightly pressing a metal flying plate on the optical medium; fastening the optical medium, the metal flying plate, the target and a template on a special target clamping machine through the press plate; turning on a nano-second pulsed laser; adjusting the optical path to focus the laser outputted from the nano-second pulse laser on the target surface; subjecting the nano-second pulsed laser to single emission to achieve single pulse laser shock on the target. The method can generate ultrahigh pressure and strain rate during production of a sample, and the application of pressure of the generated shock wave has higher planarity, completeness and repeatability, thus improving surface rigidity of micro-metal parts and improving micro-sensing sensitivity. Accordingly, a micro-driving device can provide higher drive force, torsional moment and energy.

Nanosecond pulsed electric field (nsPEF) treatments of a tumor are used to cause the tumor to express calreticulin and stimulate an immune response against the tumor and other tumors in a subject. An immune response biomarker can be measured, and further nsPEF treatments can be performed if needed to stimulate or further stimulate the immune response. Cancers that have metastasized may be treated. The treatment can be combined with CD47-blocking antibodies, doxorubicin, CTLA-4-blocking antibodies, and/or PD-1-blocking antibodies. Electrical characteristics of nsPEF treatments can be based on the size, type, and/or strength of tumors and/or a quantity of tumors in the subject.

A pulse generator circuit may include a diode configured to operate as an opening switch, a tank circuit in series with the diode having an admittance that is switchable from a first value to a second value that is different from the first value, and a switching system configured to cause the tank circuit to switch between the first value and the second value. The diode may saturate in less than 100 nanoseconds. A saturable core transformer may operate as a switch that controls the opening of the diode. The pulse generator may generate a plurality of pulses, each having a length of no more than 3 nanoseconds and an amplitude of at least 1 kilovolt. Electrodes may be connected to the pulse generator to deliver the plurality of pulses to biological cells.

The invention provides a double-resonance, wide-tuning and narrow-linewidth all-solid-state nanosecond pulse medium-infrared optical parameter oscillator comprising four parts including single-frequency pump light, a double-resonance resonant cavity, an electrical control part and seed light. A 1.064 <mu>m single-frequency pulse laser pump quasi-phase matching multi-cycle polarized crystal double-resonance parameter oscillator is adopted to acquire dual-band laser output of wide-tuning range near-infrared signal light and medium-infrared idle light. The output central wavelength is tunable within the wide spectral range, and the cavity length is dynamically adjusted through electro-optical crystal by combining a single-frequency continuous semiconductor laser seed injection technology so as to realize narrow-linewidth laser output of the optical parameter oscillator. The oscillator can be widely applied to the field of high-resolution laser spectroscopy, laser radar, laser remote sensing, environmental detection, optical-electro countermeasure and laser medicine.

The invention provides a double light path green light micropore processing device, which comprises a picosecond pulse laser, a nanosecond pulse laser, a light path calibration system and an optical focusing system, wherein the output end of the picosecond pulse laser is provided with a first reflecting mirror; the output end of the nanosecond pulse laser is provided with a second reflecting mirror; the first reflecting mirror and the second reflecting mirror are connected with a third reflecting mirror; the output end of the third reflecting mirror is provided with an optical shutter; the output end of the optical shutter is connected with a beam expanding lens; the output end of the beam expanding lens is connected with a fourth reflecting mirror; and the fourth reflecting mirror is connected with the optical focusing system through the light path calibration system. The two lasers taking the light pulse length as nanoseconds and picoseconds are adopted, the selection of light beams is controlled by a light path selection system, the use of one laser for the processing is allowed, and the two lasers can also be alternately used during the processing. A double light path system maintains the advantage that the laser processes micropores, and can aim at different processing finenesses and cost requirements to flexibly select processing modes.

The invention discloses a multi-laser polishing and reinforcing method for surfaces of additive manufacturing metal parts, and the polishing on the surfaces of the additive manufacturing metal parts can be realized by repeatedly scanning and processing the surfaces of the additive manufacturing metal parts through utilizing millisecond pulse laser and nanosecond pulse laser; during the multi-laser scanning polishing process, the additive manufacturing metal parts are subjected to thermal preservation treatment, so that the stress on the surfaces of the additive manufacturing metal parts can be evenly distributed; laser scanning reinforcement is carried out on the surfaces of the laser-polished additive manufacturing metal parts, so that the stress state on the surfaces of the additive manufacturing metal parts can be changed into pressure stress from tensile stress, the anti-fatigue property of the additive manufacturing metal parts can be enhanced, and the usage performance of the metal parts can be met; compared with a manual polishing method, the multi-laser polishing and reinforcement efficiency of the additive manufacturing metal parts is high and is as 20 times as that of the manual polishing, the non-contact rapid polishing of the additive manufacturing metal parts can be realized, the tensile stress, caused by the laser polishing, of the additive manufacturing metal parts can be eliminated, and the anti-fatigue property of the additive manufacturing metal parts can be enhanced.

Pulsed laser drivers are disclosed comprising Gallium Nitride (GaN) power transistors for driving diode laser systems requiring high current and fast pulses, such as laser drivers for LIDAR (Light Detection and Ranging) systems. Drivers are capable of delivering pulses with peak current ≥100 A, e.g. 170 A to provide high peak power, fast pulses with nanosecond rise times and nanosecond pulse duration, for driving multi-channel laser diode arrays with 40 A per channel for 120 W output per channel for a combined peak output of 480 W. For lower duty cycle, example driver circuits are disclosed comprising a high current power transistor for direct drive with drive assist. For higher duty cycle, example resonant driver circuits are disclosed comprising two high current power transistors. Implementation of resonant driver circuits with GaN technology provides fast charging for short pulse operation at higher repetition rates or for pulse code modulation.

Methods for inducing calcium mobilization in cells through the application of nanosecond pulsed electric fields (“nsPEFs”) are provided. The invention also provides a method of increasing intracellular calcium in cells through the application of nsPEFs. In one embodiment of the invention, the cells are human platelets, whereby activation and aggregation of the platelets is induced. Methods for treating an injury, trauma, or loss of blood in a subject, through the application of nsPEFs are also provided.

The invention discloses a laser cleaning and polishing composite processing method for the surface of carbon steel. By means of the method, laser cleaning and laser polishing processes are seamlesslycombined and used on the same equipment. The method can be widely applied to surface laser processing of steel parts. A nanosecond pulse laser with a certain output energy range is used, so that a corrosion layer can be evaporated; the corrosion layer on the surface of the carbon steel is quickly removed by utilizing primary laser treatment; and then laser parameters are adjusted to radiate a cleaned surface to enable a protruding fused object on the carbon steel to flow and fill and solidify a sunken part, and the polished surface with small roughness and improved performance is obtained. Therefore, defects in the prior art are overcome, fusion pits and micro-scale defects of the surface of the carbon steel after laser cleaning can be effectively repaired, the surface roughness is reduced, and the purposes of improving the laser processing efficiency of the carbon steel and keeping the surface performance are achieved.

The invention discloses a self-designed-and-constructed power supply device for performing plasma ignition with high-energy nanosecond pulse superposed high voltage direct current, which comprises a DC high voltage power supply, a nanosecond pulse power supply and a nanosecond pulse integrated DC circuit. High voltage DC output and nanosecond pulse output are superposed via nanosecond pulse integrated DC circuit to obtain a nanosecond pulse superimposed DC power supply, applied to the load. The self-designed-and-constructed nanosecond pulse superposed direct current power supply device for performing plasma ignition is small in size, compact in structure and low in cost. The high voltage DC power supply and the nanosecond pulse power supply are integrated, which has the advantages of high discharge energy and device miniaturization and facilitates the usage. In the practical application, the power supply device can be used for internal combustion engine ignition and supersonic-speed airspace engine ignition.