140 results about "Asymmetric waveform" patented technology

Method and apparatus for high field asymmetric waveform ion mobility spectrometry in an electronic chip assembly,, including an input section, an ion filter and detection section and a control section, in which ion filtering proceeds in a planar chamber under influence of high field asymmetric periodic signals, with detection integrated into the flow path, for producing accurate, real-time, data for identification of a broad range of chemical compounds.

A high field asymmetric waveform ion mobility spectrometer (FAIMS) for separating ions, and a method therefore. The FAIMS includes an electrode stack (24) having a length and comprising a plurality of electrodes (26, 28). Each electrode of the electrode stack is spaced apart from an adjacent electrode in a direction along the length of the electrode stack, and each electrode of the electrode stack has an edge that defines a portion of an edge of the electrode stack. At least an electrode (22) is spaced apart from the edge of the electrode stack in a direction approximately transverse to the length of the electrode stack, the space between the at least an electrode and the edge of the electrode stack defines an analytical gap (20) for allowing ions to propagate therebetween. Ions are separated as they move through an electric field within the analytical gap resulting from the application of an asymmetric waveform voltage to alternate electrodes of the electrode stack and application of a direct current voltage to at least some of the electrodes of the electrode stack and to the at least an electrode.

A load control device comprises a bidirectional semiconductor switch for controlling the amount of power delivered to an electrical load, and the bidirectional semiconductor switch further comprises two field effect transistors (FETs) in anti-series electrical connection. In the event that one of the FETs fails in a shorted state, and if the load control device is using a phase control dimming technique to control the load, the load control device may provide an asymmetric waveform to the electrical load. In order to determine whether this asymmetric waveform is present, a microprocessor of the load control device use voltage thresholds and/or offsets to monitor the voltage across the FETs. Thus, the microprocessor is operable to detect a fault condition of the load control device wherein the fault condition may comprise an asymmetry condition, or more particularly, a failure condition of one of the FETs.

The present invention is concerned with an ion analysis apparatus for conducting differential ion mobility analysis and mass analysis. In embodiments, the apparatus comprises a differential ion mobility device in a vacuum enclosure of a mass spectrometer, located prior to the mass analyser, wherein the pumping system of the apparatus is configure to provide an operating pressure of 0.005 kPa to 40 kPa for the differential ion mobility device, and wherein the apparatus includes a digital asymmetric waveform generator that provides a waveform of frequency of 50 kHz to 25 MHz. Examples demonstrate excellent resolving power and ion transmission. The ion mobility device can be a multipole, for example a 12-pole and radial ion focusing can be achieved by applying a quadrupole field to the device in addition to a dipole field.

Disclosed is a high field asymmetric waveform ion mobility spectrometer (FAIMS) including a set of spaced-apart parallel rods, the space between the parallel rods having first and second ends and defining an analyzer region. The apparatus includes an electrical controller for electrically coupling to the set of parallel rods, for applying at least an rf-voltage between the parallel rods of the set of parallel rods in a first operating mode and for applying a combination of an asymmetric waveform voltage and a direct current voltage between the parallel rods of the set of parallel rods in a second operating mode.

Method and apparatus for chromatographic high field asymmetric waveform ion mobility spectrometry, including a gas chromatographic analyzer section intimately coupled with an ionization section, an ion filter section, and an ion detection section, in which the sample compounds are at least somewhat separated prior to ionization, and ion filtering proceeds in a planar chamber under influence of high field asymmetric periodic signals, with detection integrated into the flow path, for producing accurate, real-time, orthogonal data for identification of a broad range of chemical compounds.

The present invention relates to a device for separation and characterization of gas-phase ions. The device incorporates an ion source, a field asymmetric waveform ion mobility spectrometry (FAIMS) analyzer, an ion mobility spectrometry (IMS) drift tube, and an ion detector. In one aspect of the invention, FAIMS operating voltages are electrically floated on top of the IMS drift voltage. In the other aspect, the FAIMS/IMS interface is implemented employing an electrodynamic ion funnel, including in particular an hourglass ion funnel. The present invention improves the efficiency (peak capacity) and sensitivity of gas-phase separations; the online FAIMS/IMS coupling creates a fundamentally novel two-dimensional gas-phase separation technology with high peak capacity, specificity, and exceptional throughput.

A differential ion mobility spectrometry or field asymmetric waveform ion mobility spectrometry (FAIMS) platform is disclosed that utilizes both gas flow and electric field, consecutively or simultaneously, to move ions through the analytical gap. The consecutive combination of flow and field enables rapid and flexible switching of the FAIMS stage “on” (for ion separation) and “off” (for high non-selective transmission) with no hardware modifications. This capability is needed for effective use of multidimensional instrument systems that couple FAIMS to mass spectrometry and/or conventional ion mobility spectrometry. The joint application of flow and field allows controlling the discrimination against high-mobility ions, maximizing it to remove the chemical noise or minimizing it to make the analyses of complex samples more predictable and uniform.

A ratio of reversible electroporation and irreversible electroporation may be controlled by selecting a symmetric waveform or asymmetric waveform to either minimize or enhance irreversible effects on cells in the target tissue. Combined reversible and irreversible electroporation includes inserting one or more therapeutic electrodes into a target tissue, introducing an electroporation compound into the target tissue, selecting a pulse waveform that is either 1) asymmetric bipolar that has positive and negative pulses with different durations, or 2) symmetric bipolar that has positive and negative pulses with the same duration, and delivering to the target tissue a series of electrical pulses having the selected pulse waveform.

An energy-absorbing hood assembly for a vehicle includes upper, lower, and middle panels. The upper and lower panels respectively include first and second interface surfaces. The upper panel is preferably secured to an inner surface of an outer panel. The middle panel has opposing first and second surfaces defining an asymmetric waveform profile, preferably having a polygonal geometry. The middle panel member is secured to the first and second interface surfaces at preselected locations along the upper and lower surfaces, thereby defining a plurality of laterally oriented asymmetric channels. The asymmetric waveform profile is configured with distinct amplitudes and wavelengths along different regions of the hood assembly, each configured to provide different predetermined levels of absorption and attenuation of kinetic energy imparted to the hood assembly by objects upon impact therebetween. Ideally, the lower and middle panels are respectively configured to controllably fail at first and second predetermined crush loads.

Disclosed are a device and method for improved interfacing of differential mobility spectrometry (DMS) or field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of substantially planar geometry to subsequent or preceding instrument stages. Interfacing is achieved using curved DMS elements, where a thick ion beam emitted by planar DMS analyzers or injected into them for ion filtering is compressed to the gap median by DMS ion focusing effect in a spatially inhomogeneous electric field. Resulting thinner beams are more effectively transmitted through necessarily constrained conductance limit apertures to subsequent instrument stages operated at a pressure lower than DMS, and/or more effectively injected into planar DMS analyzers. The technology is synergetic with slit apertures, slit aperture/ion funnels, and high-pressure ion funnel interfaces known in the art which allow for increasing cross-sectional area of MS inlets. The invention may be used in integrated analytical platforms, including, e.g., DMS/MS, LC/DMS/MS, and DMS/IMS/MS that could replace and/or enhance current LC/MS methods, e.g., for proteomics research.

The invention discloses a flat-plate type high-field asymmetric waveform ion mobility spectrometer with a noise reduction function, which comprises an ion source, a migration area and a detection unit, wherein an upper substrate and a lower substrate are arranged in the migration area in parallel; the upper substrate and the lower substrate are respectively provided with an upper migration area electrode and a lower migration area electrode; the upper migration area electrode is connected with an asymmetric waveform radio-frequency power supply and a direct-current scanning compensation power supply; and the detection unit consists of a current detection electrode and a current detection deflection electrode which are respectively arranged on the upper substrate and the lower substrate. The flat-plate type high-field asymmetric waveform ion mobility spectrometer with the noise reduction function is characterized in that one circle of migration area shielding electrode is additionally arranged on the periphery of the upper migration area electrode; meanwhile, one circle of current detection shielding electrode is additionally arranged around the current detection electrode; the two circles of shielding electrodes are respectively earthed; and the upper migration area electrode and the migration area shielding electrode as well as the current detection electrode and the current detection shielding electrode are insulated by air or insulating materials.

The present invention relates generally to separation of ions based on their transport properties. More particularly, the invention relates to separation of ionic mixtures and characterization of ions in gases using higher-order differential ion mobility spectrometry (HODIMS) enabled by asymmetric waveforms of fundamentally new types. The invention discloses a method and apparatus for separation of ionic mixtures and characterization, identification, or quantification of ions in a gas based substantially on the terms of third or higher order in a series expansion of ion mobility as a function of electric field intensity. This is achieved using a periodic, time-dependent electric field with novel waveform profiles that cancel or substantially reduce the contributions to time-averaged ion motion of the leading n (where n≧2) terms of that expansion, thereby achieving ion separations based substantially on the (n+1)th term. Separations using HODIMS with different n are expected to be highly orthogonal, enabling multidimensional separations employing HODIMS analyzers of different orders. The expected high orthogonality between HODIMS and mass spectrometry or ion mobility spectrometry would make HODIMS/MS and HODIMS/IMS combinations powerful analytical tools of broad utility.

Disclosed is a method and apparatus for detecting trace levels of a vapour in a carrier gas stream. A method according to the instant invention comprises the steps of providing a flow of a carrier gas through an analyzer region of a high field asymmetric waveform ion mobility spectrometer (22), the carrier gas including a first gas and a trace amount of a vapour. At least a first type of indicator ions are introduced into the analyzer region, and a compensation voltage for transmitting the at least a first type of indicator ions through the analyzer region, in the presence of the flow of a carrier gas and at a given asymmetric waveform voltage, is determined. The determined compensation voltage is compared to calibration data relating to a compensation voltage for transmitting the at least a first type of indicator ions through the analyzer region at the given asymmetric waveform voltage in the presence of each of a plurality of different known trace amounts of the vapour mixed with the first gas. In this way, an amount of the vapour in the carrier gas is determined, absent a step of ionizing a substantial portion of the vapour.

A multi-phase realigned voltage-controlled oscillator (MRVCO) achieves phase realignment based on charge injection in the VCO stages. The individual VCO stages provide an oscillating output signals having an asymmetric waveform with substantially different rise and fall times. This ensures that the VCO as a whole has a multiphase impulse response to the charge injection that is strictly positive or strictly negative, and substantially constant so as to be independent of the VCO phase or timing of charge injection. The MRVCO may form a component part of an implementation of a multi-phase realigned phase-locked loop (MRPLL).

The invention discloses a focusing device and a focusing method of a flat high-field asymmetric waveform ion mobility spectrometer. The flat high-field asymmetric waveform ion mobility spectrometer comprises an ion source, a mobility area and a detection unit, wherein an upper substrate and a lower substrate are placed in parallel in the mobility area; an upper mobility area electrode and a lower mobility area electrode are respectively arranged on the upper substrate and the lower substrate; and the upper mobility area electrode is connected with an asymmetric waveform radio frequency power supply and a direct current scanning compensation power supply. The focusing device is characterized in that at least one focusing area is arranged at the front end of the mobility area; and at least one focusing polar plate pair is arranged on each of the upper and lower substrates of each focusing area. The focusing method employing the focusing device is characterized in that voltage is applied to each focusing polar plate pair, so ions are gathered to the center before entering the mobility area; the applied voltage has two modes, namely a direct current focusing mode and a radio frequency focusing mode; in the direct current focusing mode, the same direct current voltage is applied to the focusing polar plate pair at intervals; and in the radio frequency focusing mode, sine radio frequency voltage is applied to each focusing polar plate pair, and the difference of the radio frequency voltage phases of the adjacent focusing polar plate pairs is 180 DEG.

A tandem instrument using a variable frequency pulsed ionization source and two separation techniques, low (IMS) and high (FAIMS) field mobility is provided. The analytical stage features a field driven FAIMS cell embedded on-axis within the IMS drift tube. The FAIMS cell includes two parallel grids of approximately the same diameter as the IMS rings and can be placed anywhere along the drift tube and biased according to their location in the voltage divider ladder to create the same IMS field. The spacing between the grids constitutes the analytical gap where ions are subject, in addition to the drift field, to the asymmetric dispersive field of the FAIMS. The oscillatory motion performed during the high and low voltages of the asymmetric waveform separates the ions according to the difference in their mobilities.

An asymmetric waveform pulse power supply is used for converting input high-voltage direct currents into asymmetric pulse square waves to be output and comprises an MOSFET half-bridge circuit, a PWM circuit and an isolation drive circuit, wherein the MOSFET half-bridge circuit is formed by MOSFETs and used for inverting the input high-voltage direct currents and then outputting the pulse square waves; the PWM circuit is used for generating a positive path of PWM signals and a negative path of PWM signals; the isolation drive circuit is used for controlling connection and cutoff states of the MOSFETs in the MOSFET half-bridge circuit according to the positive path of PWM signals and the negative path of PWM signals generated by the PWM circuit; the isolation drive circuit comprises isolation transformer which is used for isolating strong current signals in the MOSFET half-bridge circuit from weak current signals in the PWM circuit.

The invention discloses a FAIMS based on ion wind pumps, which comprises an electrical system and an ion mobility tube, wherein the ion mobility tube comprises an ion source, a separation detection system and an ion wind pumping system; a tube body of the ion mobility tube is composed of two substrates which are plated with electrodes and connected tightly with supporting beams to form air flow channels, and the electrodes comprise separation electrodes, detection electrodes, discharge electrodes and traction electrodes; wherein the separation electrodes, the detection electrodes and airflow channels among the separation electrodes and the detection electrodes form the separation detection system, the discharge electrodes, and the traction electrodes and airflow channels among the discharge electrodes and the traction electrodes form the ion wind pumping system; and the ion source is arranged on the inner side of an air inlet end of the substrate. A gaseous sample enters the ion mobility tube under the drive of the ion wind and is separated and detected by the separation detection system after being ionized by the ion source. According to the FAIMS based on ion wind pumping systems, monolithic integration can be achieved, the FAIMS based on ion wind pumping systems has the advantages of being high in integration, having no movable parts, and being simple in structure and easy to control, and highly integrated and stable FAIMS detections can be achieved.