90 results about "Channel electrode" patented technology

A tone evaluation rehabilitation training device and system, the device comprises a flexible cap body and a bandage, the cap body is integrated with a 10-channel electrode plate to accurately cover language brain areas on both sides, electroencephalogram signals are transmitted in real time through Bluetooth 5.0, and a noise reduction earphone is used for providing sound output for a patient. The microphone is used for collecting audio of a patient and transmitting the audio to the processing module for analysis, the system dynamically regulates acoustic stimulation based on the neural activation feedback module, high-precision tone recognition is achieved in combination with audio preprocessing, SpecAugment data enhancement, a CNN-Transform mixed model and an attention mechanism, and training efficiency is optimized through pre-training model fine tuning and Warmup learning rate scheduling. An initial consonant-vowel-tone three-dimensional confusion probability table is introduced to divide interference intensity grades, high and low interference task paths are dynamically switched through a semantic error rate, and an evaluation module generates a four-tone accuracy rate, an F0 curve comparison graph and a personalized rehabilitation scheme. The recognition precision is improved, the training period of special crowds is shortened, and full-period self-adaptive rehabilitation is provided for preschool children to speech disorder patients.

Generally described, one or more aspects of the present disclosure relate to methods, systems, and devices related to pre-straining bare lanes of a multilane electrode with a system for calendering a multilane electrode including a pre-strain roll device including a plurality of pre-strain rollers and a pressure roller forming a pre-strain nib and a calender roll device comprising a pair of calendering rollers forming a calendering nip positioned downstream from the pre-strain roll device.

The invention provides an information processing method and system based on a brain-computer interface, and belongs to the technical field of information processing.The method comprises the steps that brain wave signals of a user are collected through a multi-channel electrode; based on STFT, DWT and SVM models, feature extraction and pattern recognition are carried out on the brain wave signals, and control instructions corresponding to the brain wave signals are generated; and controlling the rehabilitation training equipment based on the control instruction to obtain control feedback corresponding to the brain wave signal. According to the information processing method and system based on the brain-computer interface, the signal discrimination robustness can be effectively improved, and the stability and generalizability of the system under individual differences of different patients and environmental interference are guaranteed.

The invention discloses a multi-parameter dynamic coding method for tactile feedback. The method comprises the following steps: arranging a multi-channel electrode array in a tactile sensing area, and establishing a corresponding relation between each channel of a multi-channel array electrode and a spatial position in the tactile sensing area through spatial coding; calibrating the minimum value and the maximum value of various types of electrode stimulation parameters reflecting the touch perception degree to obtain a dual-threshold calibration result; performing intensity coding according to the double-threshold calibration result; constructing a type code, wherein the type code reflects a corresponding relation between the frequency interval and the touch induction type; and generating a parameter dynamic mapping model based on the intensity code and the type code, wherein the parameter dynamic mapping model reflects a corresponding relation between an interaction characteristic between the touch sensing area and a target and an electrode stimulation parameter combination sensed by the touch sensing area. The method can be widely applied to man-machine interaction scenes needing tactile feedback.

The application discloses a preparation method of a flexible active myoelectric electrode array structure and relates to the field of flexible electronics and active electrode preparation; the structure comprises: a plurality of active electrodes; the plurality of active electrodes are arranged in a horizontal-longitudinal matrix mode; each active electrode comprises: a flexible substrate and an active flexible amplification electrode arranged on the flexible substrate; the active flexible amplification electrode comprises an electrode and a common-source amplification circuit; the electrode and the common-source amplification circuit are in one-to-one correspondence; the electrode and the common-source amplification circuit are connected; the structure realizes synchronous collection of surface myoelectric signals by multiple channels, the flexible substrate enhances the wearability of the electrode, the differential structure, that is, the common-source amplification circuit can improve the interference of common-mode signals, reduce the introduction of noise, improve the signal-to-noise ratio of myoelectric signals, and reduce signal crosstalk between different channels.

The disclosure describes a system for performing electrophoresis in microplate formats. The electrophoresis microplate, also provided as electrophoresis strips, comprises independent electrophoresis cells arranged in a rectangular grid. Each cell comprises separation channels, electrodes, and reagents sealed within covers.. Each electrophoresis cell operates autonomously, enabling parallel analytical, preparative, and affinity electrophoresis on various sample types. The disclosure facilitates efficient automation-compatible electrophoretic separation and purification across a broad range of sample types.

The invention discloses a cell sensor based on a four-channel electrode device and application of the cell sensor in pathogenic bacterium detection, and belongs to the technical field of analysis and detection. The cell sensor is formed by combining HEK 293 / hNAIP-NLRC4 cells serving as a recognition element and a ready-to-use cell culture paper chip serving as a carrier with a four-channel electrode device with a cell culture pool. The sensor constructed by taking HEK 293 / hNAIP-NLRC4 cells as a recognition element is high in sensitivity, can distinguish escherichia coli pathogenic bacteria with T3SS from escherichia coli non-pathogenic bacteria without T3SS, specifically perceives various pathogenic bacteria with T3SS, specifically recognizes non-targeted food-borne pathogenic bacteria, and provides a new thought for risk detection and research of unknown bacteria in food.

This invention discloses a flexible multichannel multilayer electrode, its fabrication method, and an electromyography (EMG) signal acquisition device. The fabrication method of the flexible multichannel multilayer electrode includes the following steps: etching and cleaning a silicon wafer; preparing an AgNW / NG solution as a conductive material and using SEBS powder to prepare an elastic substrate; fabricating a signal acquisition layer using the silicon wafer, conductive material, and SEBS powder; fabricating a wire shielding layer using the silicon wafer and SEBS powder; and fabricating an encapsulation layer and an interference signal shielding layer using the silicon wafer, conductive material, and SEBS powder; assembling the encapsulation layer, interference signal shielding layer, signal acquisition layer, and wire shielding layer sequentially from top to bottom, and connecting the signal acquisition layer to a flexible printed circuit board. This invention aims to solve the problems of high electrode impedance, low signal-to-noise ratio, and poor tensile strength of multichannel electrodes.

The present application relates to the technical field of environmental monitoring of oil pollution area, and particularly relates to a multi-channel parallel acquisition interwell three-dimensional resistivity monitoring system and method for oil storage area. The power supply, the host, the multi-channel parallel acquisition device and the four-pole AM-BN acquisition device are sequentially connected. The multi-channel parallel acquisition device comprises a multi-channel electrode conversion box, a plurality of potential channel sockets are arranged in the multi-channel electrode conversion box, the number of the potential channel sockets is the same as the number of probes, twenty-four potential channels are arranged in each potential channel socket, a relay and a current channel switch are arranged in each channel, one end of the relay is connected with a corresponding electrode on the resistivity probe, and the other end of the relay is connected with an acquisition module. The system has high acquisition efficiency, can better realize real-time monitoring of leakage, has high monitoring precision, can accurately identify small leakage in the oil storage area, and realizes remote in-situ monitoring of oil pollution area leakage.

The invention relates to an electroencephalogram signal preprocessing method and a related device thereof.The method comprises the steps that initial electroencephalogram signals collected by a multi-channel electrode array and at least one kind of auxiliary data collected synchronously with the initial electroencephalogram signals are obtained, and the auxiliary data comprise electrode impedance values and / or physiological state data; wherein the resistance reactance value indicates an electrode impedance value corresponding to the acquisition channel associated with the initial electroencephalogram signal, and the physiological data at least comprises motion posture data and / or physiological index data; performing multiple filtering processing on the initial electroencephalogram signal to obtain a filtered electroencephalogram signal; inputting the filtered electroencephalogram signals and at least one kind of auxiliary data into a signal restoration model, and optimizing the candidate electroencephalogram signals to obtain optimized target electroencephalogram signals. According to the scheme, the electroencephalogram signals can be preprocessed by dynamically adjusting the filtering parameters and utilizing the impedance value and the auxiliary data, and the quality of the electroencephalogram signals is improved.

The invention discloses a maternal and fetal electrocardio extraction method based on multi-task learning. The method comprises the steps that 1, a multi-channel electrode is used for collecting mixed electrocardio signals on the surface of the abdomen of a pregnant woman and preprocessing the mixed electrocardio signals; 2, extracting label signals required by training, and making a data set; 3, constructing a multi-task learning maternal and fetal electrocardiogram extraction network, and training a model by using a training data set in a data set; and 4, performing electrocardiogram extraction on the pregnant woman abdomen surface electrocardiogram signals by utilizing the trained model, and outputting maternal and fetal electrocardiogram waveforms and heart beat sequences thereof. The extraction precision of the maternal and fetal electrocardiosignals can be improved, and the electrocardiosignal waveform signal and the heart beat sequence thereof can be obtained at the same time.

Proposed is a radio frequency treatment handpiece including a handpiece housing having a first containing space therein and a circuit board installed in the first containing space to operate the handpiece, and having a frontside thereof being open, an electrode tip having a nozzle portion that is detachably coupled to the handpiece housing and provided with an RF electrode for generating radio frequency waves, an electrode assembly installed in the first containing space, provided with a valve supply channel that receives a gaseous refrigerant from a second containing space and a main body, and includes a power distributer for applying electric power to the electrode tip and a solenoid valve configured to communicate with the valve supply channel and to control flow of the gaseous refrigerant, and an actuator coupled to the electrode assembly to vibrate the electrode assembly according to a control signal.

The invention discloses a controlled-release PRP pelvic floor muscle repair system for a multi-channel electrode. The system comprises a plurality of controlled-release systems and a porous silica gel protective sleeve arranged on the outer sides of the controlled-release systems in a sleeving mode. The plurality of controlled release systems comprise a plurality of electrode probes and PRP controlled release functional layers which are respectively sleeved on the outer sides of the electrode probes and are matched with the electrode probes in shape; the PRP controlled-release functional layer comprises a porous matrix and a PRP adsorption layer coated on the porous matrix; the porous matrix comprises an anti-percolation membrane layer and a micron-scale or nano-scale fiber network carrier, and the micron-scale or nano-scale fiber network carrier is coated with the PRP adsorption layer; and the micron-scale or nano-scale fiber network carrier is subjected to alkali liquor treatment before the PRP adsorption layer is coated. According to the repair system, by designing a special carrier structure and a surface treatment process, efficient adsorption of PRP is achieved, mutual cooperation with electrical stimulation is achieved, precise aggregation of PRP and electrical stimulation trigger type controllable release are achieved, and the key problem of electrical stimulation and PRP collaborative treatment in the prior art is solved.

A multiple gate system for realizing the quantum anomalous Hall effect, including a top channel electrode which controls carrier density and electric field in a conduction channel, a first dielectric layer for the top channel gate, a patterned contact gate electrode which controls earner density on the contact and screens the top channel electrode's electric field on the contact, and a second dielectric layer for the contact gate, an electrically tunable material comprising semiconducting molybdenum ditelluride in the form of a first atomic sheet and a second atomic sheet, wherein first atomic sheet is rotated planarly from the second atomic sheet by about 2.5 to about 5 degrees, to form a geometrically stacked homobilayer moiré superlattice configured to host ferromagnetic states that spontaneously break time-reversal symmetry, where a perpendicular electric field is applied to the electrically tunable material, tuning the quantum anomalous Hall effect.

A multiple gate system for realizing the quantum anomalous Hall effect, including a top channel electrode which controls carrier density and electric field in a conduction channel, a first dielectric layer for the top channel gate, a patterned contact gate electrode which controls earner density on the contact and screens the top channel electrode's electric field on the contact, and a second dielectric layer for the contact gate, an electrically tunable material comprising semiconducting molybdenum ditelluride in the form of a first atomic sheet and a second atomic sheet, wherein first atomic sheet is rotated planarly from the second atomic sheet by about 2.5 to about 5 degrees, to form a geometrically stacked homobilayer moiré superlattice configured to host ferromagnetic states that spontaneously break time-reversal symmetry, where a perpendicular electric field is applied to the electrically tunable material, tuning the quantum anomalous Hall effect.

The present invention relates to the technical field of liquid flow battery manufacturing equipment, and specifically to a transport and stacking system and method for transporting and stacking electrode plates with flow channels. The transport and stacking system for electrode plates with flow channels includes: a servo system; an adsorption tooling includes a suction cup frame, the suction cup frame is connected to the servo system, and a suction cup is installed on the suction cup frame; a working surface is provided at the bottom of the suction cup, and the working surface is provided with a plurality of negative pressure adsorption ports for adsorbing the electrode plate; a gas compensation system includes a plurality of compensation nozzles, the compensation nozzles are provided on the adsorption tooling, and the plurality of compensation nozzles are provided circumferentially around the working surface of the suction cup; a stacking table, the stacking table is provided with at least one guide blocking rod, the guide blocking rod is vertically provided and can be raised and lowered, and the guide blocking rod is directly opposite to the through-holes of the stacked electrode plates on the stacking station. Through the above arrangement, the pressure below the electrode plate can be compensated without changing the servo system and the release height of the electrode plate, thereby slowing down the falling speed of the electrode plate and protecting the electrode plate.

The present application relates to the technical field of fracture monitoring, and is a pulse fracturing active fracture monitoring method based on seismic-electric coupling, which comprises using a fracturing nipple excitation source as an active elastic wave source, receiving the electric signal generated by seismic-electric coupling by using a multi-channel electrode array arranged, adopting time-frequency analysis and fracture inversion based on a frequency domain template to realize inversion and visualized output of the existence, spatial position, trend and scale of the fracture. The present application excites a pulse by using a fracturing nipple, generates an elastic wave signal, emits an excitation current, enhances the intensity of the seismic-electric effect electric signal, analyzes the change of the electric field around the fracturing nipple, and thus realizes real-time active monitoring of the development and distribution of fracturing cracks and improves the accuracy and real-time performance of crack detection.

The present application relates to a kind of spinal cord epidural electrical stimulation electrode for rhesus monkey spinal cord injury repair and its preparation method, belong to medical instrument technical field.The electrode body includes composite flexible substrate;Composite flexible substrate includes insulating substrate layer, conductive layer and insulating protective layer arranged in sequence;Wherein, conductive layer is provided with multi-channel electrode site array;Multi-channel electrode site array is arranged into at least two columns along the length direction of composite flexible substrate, and each column includes multiple electrode sites;Micropore array is arranged in the first surface of electrode body;Wherein first surface is the contact surface for being contacted with rhesus monkey spinal cord;Micropore array includes multiple micropores, each micropore penetrates insulating protective layer, and micropore bottom end stops at the surface of conductive layer.The present application not only improves the electrode and spinal cord dura mater surface adhesion, also enhances the position stability of electrical stimulation site, guarantees the accuracy and reliability of long-term electrical stimulation effect.

The present application relates to a kind of microchannel electrode support and its preparation method and application, the electrode support is relatively provided with dense layer and porous layer along the thickness direction, microchannel is provided between the dense layer and porous layer, the microchannel extends from the dense layer to the porous layer direction;The microchannel is variable-diameter channel, its aperture gradually decreases from the dense layer to the porous layer along the extension direction.Pore size distribution of the electrode support is 0.5~40 μm, the thickness is 600~1500 μm, porosity is 30~70%.The microchannel electrode support is mainly prepared by phase inversion process, is formed by key steps such as solvent replacement, constant temperature drying and high-temperature calcination in turn.Compared with prior art, the microchannel electrode support of the present application maintains high porosity under high temperature conditions, so that fuel gas and oxygen can be quickly absorbed and released, thereby accelerating the chemical reaction rate, improve the working efficiency of SOFC / SOEC.

The multi-channel electrode tube 103 includes at least four deflection plates 300-307. Each of the deflection plates 300-307 is positioned opposite another deflection plate 300-307 across the path of the electron beam 102 passing through the multi-channel electrode tube 103. The voltage difference between the pair of deflection plates 300-307 positioned opposite each other across the path of the electron beam 102 is determined. Then, based on the voltage difference, the position of the electron beam 102 in the multi-channel electrode tube 103 is determined.

The present application relates to a kind of based on motor imagination trigger's electric stimulation synchronous closed loop multimodal neuroregulation system, belong to medical rehabilitation engineering and neural engineering technical field.The system includes: electroencephalogram signal acquisition and processing module, for real-time acquisition user sensory motor cortex electroencephalogram signal, and extract the event-related desynchronization features of motor imagination task in the electroencephalogram signal by time-frequency analysis model;Motor intention recognition and trigger module generates synchronous trigger signal;Functional electric stimulation module, through multi-channel electrode device drive surface electrode output electric stimulation pulse to target area, drive target action;Transcutaneous auricular vagus nerve electric stimulation module, output and motor intention duration synchronous stimulation pulse;Central control and synchronization module, for coordination control timing.Formed " intention recognition-synchronous control-assisted movement" complete closed loop, provides a kind of efficient, accurate, individualized neural engineering solution.

The invention provides a flow battery pressure drop calculation method and an applicable flow battery, the flow battery comprises an electrode and a flow channel region, the flow channel region is in direct contact with the electrode, the flow channel region comprises a flow channel and a flow channel rib, and the flow battery pressure drop calculation method comprises the following steps: presetting physical parameters of a test electrode; measuring the pressure drop of the test electrode, and recording the measured flow of the test electrode and the measured pressure drop corresponding to the measured flow; electrode physical property parameters are calculated according to the measured flow and the measured pressure drop; and calculating a flow channel electrode voltage drop, a flow channel rib electrode voltage drop and a flow channel voltage drop according to the electrode physical property parameters, and calculating the total voltage drop of the battery according to the flow channel electrode voltage drop, the flow channel rib electrode voltage drop and the flow channel voltage drop. The flow battery voltage drop calculation method and the applicable flow battery provided by the invention can accurately evaluate the voltage drop of the electric pile of the flow battery, and are beneficial to the structural optimization of the flow battery.

An indigo electrochemical reduction reactor and indigo electrochemical reduction reaction method using a micro-channel carbon felt electrode. A reaction device of the reactor comprises a cathode casing, an insulating gasket, a current collector, a micro-channel carbon felt electrode, a separator, an oxygen evolution electrode, an anode channel, and an anode casing. A micro-channel network for a cathode solution to flow is provided inside the micro-channel carbon felt electrode; the oxygen evolution electrode and the carbon felt channel electrode are arranged in parallel, and are separated by the separator therebetween; the current collector is closely attached to the outer surface of the micro-channel carbon felt electrode; the insulating gasket is closely attached to the outer surface of the current collector; the cathode casing is closely attached to the outer surface of the insulating gasket. Further provided in the present invention is an indigo electrochemical reduction reaction method based on the reactor. The present invention can implement direct electroreduction of indigo without a chemical reducing agent.

The invention relates to the technical field of monitoring, and discloses a carbon nanotube fiber-based multichannel electrode pool for neural stem cell culture and signal acquisition, the carbon nanotube fiber-based multichannel electrode pool comprises a baffle plate, the upper surface of the baffle plate is provided with a cell culture dish, the cell culture dish is internally provided with a cell culture pool, one side of the cell culture pool is provided with a separator plate, and the separator plate is provided with a carbon nanotube fiber. The upper surface of the baffle plate is provided with a terminal display screen, and the upper surface of the baffle plate is provided with a conductive contact. According to the invention, the electrode adopts the carbon nanotube fiber as a conductive material, the conductivity reaches 1000-1500S / cm, the conductive sensitivity is excellent, and the electric signal characteristics of neural stem cells can be accurately captured; the three conductive contacts arranged at equal intervals are in full contact with cell sap, an electric signal direct transmission mechanism is matched, the data error rate is smaller than or equal to + / -1.2%, compared with a traditional fluorescent dye method and a cell counting method, manual observation and counting errors are greatly reduced, and reliable data support is provided for cell viability evaluation.

The invention belongs to the technical field of bio-electricity signal processing, and particularly relates to an eye movement classification method based on multi-channel EOG signal airspace and inter-channel feature fusion. Through the multi-channel electrode layout design, the spatial resolution of eye movement signals is enhanced, and noise interference of a traditional dual-electrode layout is avoided; a CSP spatial domain feature extraction method is adopted, 28 groups of CSP projection matrixes are constructed for 8 types of eye movement tasks, and the distinguishing capability of spatial domain features on tiny eye movement modes is improved; through arranging a time domain and frequency domain traditional feature extraction module, a space domain feature extraction module and an inter-channel correlation feature extraction module, correlation features are extracted so as to improve classification accuracy and stability. According to the method, a complete technical chain of multi-channel electro-oculogram signal acquisition layout, preprocessing, feature extraction and classification decision is adopted, so that the bottleneck of insufficient utilization of spatial information and missing of channel collaboration in a traditional method is solved. Experimental verification shows that the stability under individual difference and the average accuracy rate are 88.23%.

The present application provides a device for measuring the contact impedance between a multi-channel electromyography electrode and a biological organism, comprising: a control processor circuit, a power supply circuit, a measurement circuit, a first multi-channel switch, a second multi-channel switch, a third multi-channel switch, a fourth multi-channel switch, an electrode interface and a grounding interface, wherein the control processor circuit is connected to other circuits and switches; the electrode interface is provided with a multi-channel connector, and the multi-channel connector is separately connected to the first multi-channel switch, the third multi-channel switch and the fourth multi-channel switch; the measurement circuit is further separately connected to the second multi-channel switch and the grounding interface; the second multi-channel switch is further connected to the first multi-channel switch; the first multi-channel switch is further separately connected to the third multi-channel switch, the fourth multi-channel switch and the electrode interface; and the third multi-channel switch and the fourth multi-channel switch are connected to the electrode interface, respectively.

The application belongs to the technical field of nanomaterials and biological analysis, and particularly relates to a ratio type photoelectrochemical analysis method based on multifunctional CeO2 / CdS and interface etching. First, a multifunctional CeO2 / CdS nanocomposite is synthesized by an in-situ growth method, and the nanocomposite has photoelectric properties of CdS and CeO2 peroxidase activity; second, a beacon antibody labeled with nanogold and glucose oxidase is prepared by an electrostatic adsorption method, a target protein, the beacon antibody and an antibody coated on an enzyme-labeled microplate are mixed and incubated to form an immune complex, and after glucose is added, H2O2 is generated by catalysis of the glucose oxidase on the beacon antibody; the generated H2O2 is catalyzed by CeO2 in the CeO2 / CdS nanocomposite to generate hydroxyl radicals, and in-situ etching of CdS in the electrode interface reduces the photocurrent, and a photocurrent intensity ratio (Iw / Ic) of a double-channel electrode has a linear relationship with the concentration of the target protein, so that quantitative analysis can be realized. The application has a sensitive response to the detection of proteins and has a fast detection speed.

The invention belongs to the technical field of flexible sensors, and particularly relates to a compound enzyme immobilized electrode material, a preparation method and flexible wearable equipment. The invention aims to provide a compound enzyme immobilized electrode, a preparation method and flexible wearable equipment. According to the compound enzyme immobilized electrode, an enzyme immobilization method of an ionic liquid gel microsphere and carbon nanotube composite system is adopted, and the problems that the enzyme activity retention rate is low, the service life is short, the conductive network structure is incomplete and the electron transfer efficiency is low can be solved; furthermore, the invention provides wearable equipment with a multi-channel electrode array and an independent signal acquisition structure, so that the problems of low system integration level and single detection function are solved; and a pluggable flexible patch structure, a standardized structure design and an independent electrode packaging design are provided, so that the problems that the connection between the electrode and a circuit is unstable and the activity of the electrode is reduced during long-term storage are solved.

The invention belongs to the technical field of tunnel natural electric field methods, and provides a tunnel natural electric field water detection system and method based on hole-tunnel multi-angle combined observation. The measuring electrode system comprises a two-dimensional array electrode arranged on a tunnel face, a one-dimensional longitudinal electrode system arranged in a drill hole of the tunnel face and a reference electrode arranged in a static area of the tunnel, the two-dimensional array electrode and the one-dimensional longitudinal electrode system are arranged in a spatial cross mode, and the reference electrode is connected to the two-dimensional array electrode and the one-dimensional longitudinal electrode system of the tunnel face. A plurality of paths of electrodes are formed; the detection control host is configured to issue an information acquisition instruction, set an independent differential acquisition channel for each path of electrode, acquire potential difference data between all the measuring electrodes and the reference electrode under a unified clock and synchronous control, interpret and image potential difference data signals between all the measuring electrodes and the reference electrode, and determine the potential difference data signals between all the measuring electrodes and the reference electrode. And determining the position of the abnormal body in front of the tunnel and the underground water migration trend.

A plasma forming device includes a housing unit and an electrode unit. The housing unit includes an inner housing having a first gas inlet, a reaction channel that spatially communicates with the first gas inlet, and an inner housing opening that spatially communicates with the reaction channel. The first gas inlet is adapted for entrance of a first gas therethrough into the reaction channel. The electrode unit includes an inner dielectric tube extending in the reaction channel, an inner electrode sleeved on the inner dielectric tube, an outer dielectric tube disposed in the reaction channel, and surrounding the inner electrode and a portion of the inner dielectric tube, and an outer electrode sleeved on the outer dielectric tube and aligned with the inner electrode. The inner electrode and the outer dielectric tube cooperatively define a curved passage that is adapted for passage of the first gas therethrough.