73 results about "Dual frequency ultrasound" patented technology

The invention discloses a double-frequency ultrasonic multi-dimensional focused noninvasive cerebrovascular thrombolytic system, which is characterized in that: a craniocerebral vertical positioning ring is worn for image detection and acquisition of positioning image data; the position and treatment position of a focus can be determined by using a medical image three-dimensional reconstruction technique; a multi-dimensional low-power low-frequency ultrasonic transducer is placed on the same cut face of a focus of cerebral embolism to form a stable ultrasonic cavitation effect is formed in the thrombus or the focus of the cerebral embolism; a medium-frequency and / or high-frequency focused ultrasound transducer is used to radiate the thrombus by a focused ultrasonic focal point from a position on the same cut face of body surface which is most close to the focus, the focused ultrasonic waves are focused with high power, high sound intensity and high accuracy and are intermittently emitted in a pulse modulation ultrasonic wave mode in a short time to form an instant unstable ultrasonic cavitation effect in the thrombus to induce blasting in the thrombus, so that the thrombus is disintegrated and dissolved quickly; and while the thrombus is quickly and effectively dissolved, the inner wall of the blood vessel and surrounding normal brain tissues are not damaged, so in-vitro noninvasive thrombolytic effect is achieved.

A dual-frequency ultrasound transducer, comprising a piezo-electric element bonded to a substrate, has two resonant vibration modes: a low frequency mechanical bending resonance mode and a relatively high frequency thickness resonance mode. The low frequency bending resonance mode occurs when the piezo-electric element is excited, in use, by a voltage which includes a low frequency oscillating component. The high frequency thickness resonance mode occurs when the piezo-electric element is excited, in use, by a voltage which includes a relatively high frequency oscillating component. The transducer may include a mounting arrangement, such as a support ring securing the periphery of the substrate to an underlying base layer that enhances the depth of penetration and focus of the ultrasound.

The invention provides a biological tissue matrix material, and a preparation method and a purpose thereof. The biological tissue matrix material is characterized by comprising an extracellular matrix, wherein the extracellular matrix comprises collagenous fiber, growth factors and fibronectin. The biological tissue matrix material is prepared from small intestinal submucosa matrix materials. The preparation method is characterized by comprising the following steps that decellularization is performed: decellularized liquid contains trypsin and PBS solution, and also contains EDTA, EDTA-2Na or EDTA-4Na; the decellularized liquid is used for treatment in multi-frequency ultrasonic environment for decellularization; the dual-frequency ultrasound at least contains two ultrasonic frequencies with different frequencies. The decellularization process technology is improved; the DNA residual quantity of the obtained product is lower; the immunogenicity is lower; the anti-infection capability is higher; the restoration capability is higher.

The invention discloses a method for degrading an organophosphorus pesticide based on a sweep-frequency double-frequency ultrasonic technology, and relates to the fields of agricultural environment and water protection. The method comprises the following steps of: putting an aqueous solution of the organophosphorus pesticide dimethoate into a reactor of equipment; and by setting different frequencies and different sweep frequency periods of a single frequency or a double frequency, setting the total volume of the aqueous solution of the organophosphorus pesticide dimethoate in the reactor, and performing sweep-frequency ultrasonic treatment at 25DEG C fro 40 to 180 minutes, wherein the concentration of the organophosphorus pesticide is 1.8-5.4mg / L. Toxic and harmful pollutants are degraded by the ultrasonic technology to the greatest extent, and the method has the advantages of high efficiency, no secondary pollution and energy conservation.

The invention discloses a device and a method for ultra precise polishing of a double-frequency acoustic cavitation nanofluid under the magnetic control action. The device comprises a polishing liquid pool, a hydraulic pump, an ultrasonic reactor, a double-frequency ultrasound device, a nano-abrasive container, an alternating current power supply, an alternating current coil and a workpiece frame. The method is realized mainly through the following steps: (1) a polishing liquid is placed in the polishing liquid pool, and then is sent in the ultrasonic reactor through the hydraulic pump; (2) nano-abrasives are placed in the nano-abrasive container, and flow into the ultrasonic reactor through a third connecting pipe; (3) the polishing liquid and the nano-abrasives are mixed in the ultrasonic reactor into a nano-abrasive and polishing liquid mixed solution, and the mixed solution is subjected to acoustic cavitation under the action of the double-frequency ultrasound device; (4) the mixed solution is ejected under acoustic cavitation and pressure; (5) the alternating current coil generates an alternating current magnetic field, and the ejected nano-abrasive and polishing liquid mixed solution polishes a workpiece under the action of the alternating current magnetic field. According to the device and the method, the plane and the curved surfaces of parts are polished with high precision, high consistency and high surface quality.

The invention provides a method for detecting interface contact strength by double frequency ultrasound, which mainly comprises the following steps of: generating double frequency ultrasound exciting signals by using a signal generator, and amplifying by using a power amplifier; transmitting the signals by utilizing a transmitting transducer, receiving the signals by utilizing a receiving transducer after the transducers are calibrated; exciting the double frequency ultrasonic signals in a sample to be detected, and processing the signals by utilizing fast Fourier transform; converting the obtained electric signal amplitude into the absolute displacement amplitude; and calculating a nonlinear parameter, a linear contact strength value and a second-order contact strength value. A calibration procedure for absolute vibration amplitude is introduced, and the concrete contact strength value can be calculated, so the quantitative detection on a solid interface can be realized. The double frequency ultrasound is adopted for detection; and compared with the conventional solid interface contact strength ultrasound detection method, the technology can effectively enhance the detection for the contact strength of the solid interface.

The invention discloses a method for detecting a flight time of an ultrasonic wave in flow speed measurement and belongs to the technical field of detection of an ultrasonic wave instrument. The technical scheme of the method is as follows: the flight time of the ultrasonic wave is calculated by a method of double-frequency ultrasonic wave phase detection so as to effectively increase the range of instrument measurement. In addition, the method for detecting the flight time of the ultrasonic wave in the flow speed measurement is different from other multi-frequency ultrasonic wave measuring methods, and a solution under a condition that the phase drifting exits in a sensor is provided, so that the method has better practicability in the detection of the flow speed or the flow rate of the ultrasonic wave.

The invention relates to a method for extracting toosendanin from cortex meliae. The method comprises the following processing steps: cleaning dry mature cortex meliae and then crushing the mature cortex meliae by a pulverizer, grinding the mature cortex meliae into powder, drying the powder and adding a 60% ethanol solvent; adjusting the pH value of the solution to 4-6, and adding cellulase for enzymolysis; putting the extracting solution into a double-frequency ultrasonic extractor to obtain an enzymatic hydrolysate; carrying out high-temperature inactivation on the enzymatic hydrolysate to obtain an extracting solution; centrifuging, taking supernate, extracting by use of chloroform, and drying by use of anhydrous sodium sulfate; carrying out suction filtration, concentrating, adding ethanol and heating for dissolving; dropping petroleum ether until the mixture becomes a turbid matter; stewing for separating out a flavescent solid, namely the toosendanin. According to the method, the cortex meliae is taken as the raw material; the stacking effect of enzymolysis and a double-frequency ultrasonic wave is fully utilized; the toosendanin in the cortex meliae is dissolved to the greatest extent; the high-purity toosendanin can be obtained by virtue of extraction and crystallization. The method has the advantages of being simple in equipment, low in extraction cost, high in extraction efficiency, mild in reaction condition, less in solvent consumption, free of pollution and the like.

The invention relates to a multi-information fusion weld defect detection system and method. The system comprises an infrared thermal imaging detection module, an ultrasonic detection module, a visible light detection module, an information processing module, an image matching module and a visual display module. By fusing visible light, infrared thermal imaging and ultrasonic detection technologies, detection of surface and internal defects of a weld joint is realized so that the accuracy of weld joint detection is improved; the ultrasonic array detection and the infrared thermal imaging detection are used for respectively detecting the internal defect information of the weld joint so that the three-dimensional visual imaging of the internal defect of the weld joint is realized, and a basis is provided for the weld joint quality evaluation and the improvement of a welding process; an ultrasonic thermal excitation device in the infrared thermal imaging detection module and an ultrasonicgeneration device in the ultrasonic detection module select double-frequency ultrasonic generation devices, corresponding ultrasonic waves are generated and emitted according to the ultrasonic frequency required by the respective modules, and synchronous measurement of ultrasonic detection and infrared thermal imaging detection is realized.

The invention discloses a double-frequency ultrasonic chemical reactor which is characterized by adopting a cylinder body structure and comprising an outer cylinder, an inner cylinder, a bottom plate, a lifting cylinder in the inner cylinder, a water inlet pipe and a water outlet arranged on the side wall of the outer cylinder, wherein a cover plate is arranged on the inner cylinder; two groups of ultrasonic transducers outside the cylinder body are respectively arranged on the cover plate and the bottom plate; one group of ultrasonic transducers consist of top high-frequency ultrasonic transducers and top low-frequency ultrasonic transducers, which are mutually spaced and uniformly distributed on the cover plate; and the other group of ultrasonic transducers consist of bottom high-frequency ultrasonic transducers and bottom low-frequency ultrasonic transducers, which are vertically and relatively arranged on the bottom plate. The invention effectively enhances the distribution uniformity of an ultrasonic acoustic field in the reactor, obviously increases the ultrasonic cavitation efficiency, prolongs the service life of equipment and can be applied to various industrial waste water, particularly to the degradation of high-concentrated organic waste water.

The invention discloses a dust concentration detection system based on dual-frequency ultrasound, and a detection method thereof. A dual-frequency ultrasonic sensing unit including a first ultrasonicsensor and a second ultrasonic sensor is adopted to respectively acquire a first ultrasonic signal and a second ultrasonic signal, a temperature sensor is adopted to acquire a temperature signal, thefirst ultrasonic signal and the second ultrasonic signal undergo environmental compensation, the volume concentration of dual-frequency ultrasound compounded multi-phase particles is obtained by a feature fusion algorithm in order to realize the complementation of the test performance or test data, make up for the deficiency of single frequency detection and complete the fast, accurate and efficient detection of a complex test object. A controller is controlled to receive the concentration data in an interrupt mode, so no waiting time is required, the parallel implementation of signal acquisition and concentration calculation is realized, and the detection efficiency is improved.

The invention discloses a method for extracting sinomenine hydrochloride from caulis sinomenii. The method comprises the following steps: crushing sinomenium acutum roots; sieving by a 40-mesh sieve; adding 5-8 times of a 60-70% ethanol liquid; extracting for 1-2 hours in a double frequency ultrasonic device; filtering and decompressing and concentrating; and purifying the filtrate by virtue of column chromatography on silica gel to obtain high purity sinomenine hydrochloride. The method disclosed by the invention is simple in process and high is recovery rate and the separated sinomenine hydrochloride is high in purity.

The invention relates to an extraction method of fennel volatile oil and particularly relates to a method for extracting the fennel volatile oil by double-frequency ultrasonic waves. The extraction method comprises the steps of drying and smashing the fennel; putting into a glass vessel; adding 60-70% ethanol solution which is 8-10 times as much as fennel; constantly extracting for 30-60 minutes at 50-70DEG C by using the double-frequency ultrasonic waves, wherein the frequency of ultrasonic wave is 20KHz and 40KHz, and the power of the ultrasonic wave is 400-500W; filtering; concentrating the filtrate in a rotary evaporator till the filtrate has no alcohol smell; extracting with the organic solvent for 1-3 times; mixing the filtrates; drying and dehydrating by anhydrous sodium sulfate; and concentrating at reduced pressure so as to obtain the water white fennel volatile oil. The method for extracting the fennel volatile oil by the double-frequency ultrasonic waves is simple, has short extraction time and low energy consumption, is much higher than traditional extraction method in term of yield of the volatile oil, and is applicable to industrial production.

The invention discloses a method for extracting piperis longi volatile oil and particularly relates to a method for extracting piperis longi volatile oil by employing double-frequency ultrasonic wave. The method comprises the following processing steps: (1) pretreatment of piperis longi medicinal material; (2) double-frequency ultrasonic wave extraction; and (3) extraction by using an organic solvent, drying and dewatering anhydrous sodium sulfate, and carrying out vacuum concentration so as to obtain the piperis longi volatile oil. The piperis longi volatile oil is extracted by adopting the double-frequency ultrasonic wave, the method is simple in process, short in extraction time and low in energy consumption, the yield of volatile oil is significantly higher than that of the traditional extraction method, and the method is suitable for industrial production.

The invention discloses a rapid emergency monitoring system and method for landslide disasters along rivers, and the method comprises the following steps: satellite remote sensing positioning is performed, and an instruction is sent to a ground base station disposed at an area nearby an easy landslide; a ground base station dispatches an unmanned aerial vehicle and an unmanned ship to a disastersite; a high-definition camera carried by an unmanned aerial vehicle and a high-low double-frequency ultrasonic detector, a current meter and a turbidity meter carried by an unmanned ship are used forcollecting original data of an affected river channel; data is sent to a cloud database for calculation; and a calculation result is fed back to the ground base station, the ground base station establishes two-dimensional and three-dimensional imaging models of landslide disaster forms, river channel blocking conditions and river channel pollutant distribution according to the result, original data and a processing result are stored in the cloud big data platform, and the processing result is sent to related departments for rapid disaster relief guidance. According to the invention, the problem that roads are blocked and communication equipment is paralyzed in disaster areas along rivers and cannot communicate with the outside is solved, landslide disasters along rivers can be quickly responded and monitored, and disaster relief reference is provided for related departments.

The invention relates to a method for extracting asiaticoside from centella. The method for extracting the asiaticoside from the centella comprises the following processing steps: smashing raw materials, sieving by adopting a sieve with 80 meshes, fermenting by adopting compound enzyme, adding 50-60% ethyl alcohol with the amount being 5-8 times that of the raw material into the fermented raw material, placing the obtained mixture into a double-frequency ultrasonic extractor, extracting at the temperature of 50-60 DEG C for 60-90 minutes with ultrasonic frequencies being 40KHz and 80KHz and power being 400-600W, filtering, concentrating, carrying out petroleum ether-water extraction, taking a lower layer, and carrying out separation and purification by virtue of an alumina column, concentration and recrystallization, so that the asiaticoside is obtained. The method for extracting the asiaticoside from the centella is short in extraction time, high in yield, easy in operation, safe and reliable, high in efficiency and energy-saving and is applicable to industrial production.

The present invention includes a device and method for determining the flow of one or more phases of a multiphase fluid mixture comprising: a tube, a pipe, a main body or any combinations thereof comprising an interior and an exterior, wherein the interior receives a multiphase fluid mixture for the determination of the fractions in the multiphase; a first ultrasound field detector ring comprising: two or more pairs of transversal paired dual frequency ultrasound transmitter / receivers are on the same normal plane and are positioned in a transversal direction to a flow of the multiphase fluid mixture on the exterior of the tube, pipe, or main body, wherein the sampled volume covers a part of or the whole cross-section of the flow volume; and a computer connected to the ultrasound transmitter / receivers that determines the one or more phases of a multiphase fluid mixture.

The present invention includes a device and method for determining the flow of one or more phases of a multiphase fluid mixture comprising: a tube, a pipe, a main body or any combinations thereof comprising an interior and an exterior, wherein the interior receives a multiphase fluid mixture for the determination of the fractions in the multiphase; a first ultrasound field detector ring comprising: two or more pairs of transversal paired dual frequency ultrasound transmitter / receivers are on the same normal plane and are positioned in a transversal direction to a flow of the multiphase fluid mixture on the exterior of the tube, pipe, or main body, wherein the sampled volume covers a part of or the whole cross-section of the flow volume; and a computer connected to the ultrasound transmitter / receivers that determines the one or more phases of a multiphase fluid mixture.

The invention discloses a cleaning process of an optical glass lens. Firstly, cleaning fluid is combined with high-voltage pulse electric field treatment and double-frequency ultrasonic wave alternatetreatment for cleaning, oil dirt, dirt and other contaminants on the surface of the optical glass lens can be effectively removed, high-voltage pulse electric field treatment cooperates with taurinedihydroxyethyl amine oxide and cetyl pyridinium chloride in the cleaning fluid, mildew on the surface of the optical glass lens can be effectively killed, a good vibration effect is achieved through the cooperation of high-voltage pulse electric field treatment and double-frequency ultrasonic wave alternate treatment, the oil dirt, the dirt and other contaminants on the surface of the optical glass lens can be effectively separated out, and the cleaning effect is improved; and then deionized water is combined with double-frequency microwave alternate treatment and double-frequency ultrasonic wave alternate treatment for washing, the oil dirt, the dirt and other contaminants on the surface of the optical glass lens can be further removed through the vibrating performance of double-frequencymicrowave alternate treatment and double-frequency ultrasonic wave alternate treatment, and the cleaning efficiency is improved.

This invention relates to a method of double frequency and supersonic alternating and strengthening ultra-threshold flow extraction of nature medical plant efficient components, which comprises the following steps: a, pre-processing of the materials, which comprises purifying, drying, grinding and filtering through ten to twenty pieces; using the extraction device to extract and separate the materials with its double frequency as 16kHz to 100kHz, power as 0 to 1000W, acoustic intensity as 0.2 to 1500W / cm2ú¼radiating time as two to five hours.

The invention provides a biological tissue matrix material, and a preparation method and a purpose thereof. The biological tissue matrix material is characterized by comprising an extracellular matrix, wherein the extracellular matrix comprises collagenous fiber, growth factors and fibronectin. The biological tissue matrix material is prepared from small intestinal submucosa matrix materials. The preparation method is characterized by comprising the following steps that decellularization is performed: decellularized liquid contains trypsin and PBS solution, and also contains EDTA, EDTA-2Na or EDTA-4Na; the decellularized liquid is used for treatment in multi-frequency ultrasonic environment for decellularization; the dual-frequency ultrasound at least contains two ultrasonic frequencies with different frequencies. The decellularization process technology is improved; the DNA residual quantity of the obtained product is lower; the immunogenicity is lower; the anti-infection capability is higher; the restoration capability is higher.

The present invention includes a device and method for determining the flow of one or more phases of a multiphase fluid mixture comprising: a tube, a pipe, a main body or any combinations thereof comprising an interior and an exterior, wherein the interior receives a multiphase fluid mixture for the determination of the fractions in the multiphase; a first ultrasound field detector ring comprising: two or more pairs of transversal paired dual frequency ultrasound transmitter / receivers are on the same normal plane and are positioned in a transversal direction to a flow of the multiphase fluid mixture on the exterior of the tube, pipe, or main body, wherein the sampled volume covers a part of or the whole cross-section of the flow volume; and a computer connected to the ultrasound transmitter / receivers that determines the one or more phases of a multiphase fluid mixture.

The invention relates to a detection and ablation integrated dual mapping system. The dual mapping system includes a differential frequency focused ultrasonic transducer and a dual frequency ultrasonic signal generator; the differential frequency focused ultrasonic transducer emits two confocal ultrasound beams of different frequencies, generates a wave interference effect at a focal point, and generate differential frequency vibration sound. The dual mapping detection system further includes a physical mapping system and a physiological mapping system; the physical mapping system obtains a detection surface of a target nerve position through a low-frequency vibration amplitude; and the physiological mapping system detects the therapeutic target, located on the detection surface, of the target nerve through physical stimulation, and the physical mapping system quickly maps the position or the relative position of the detection surface where the target nerve is located and then accurately maps on the detection surface through the physiological mapping system. The detection and ablation integrated dual mapping system has the following advantages that the detection and ablation integrated dual mapping system can be applied to tissues inside a human body, the detection surface is quickly obtained, and then the target nerve is accurately stimulated through the detection surface to achieve the purpose of rapid and accurate treatment.

The invention relates to a novel method for extracting vincaleukoblastinum from catharanthus roseus. The novel method comprises the following steps: removing impurities in catharanthus roseus, crushing, screening by using a 50-mesh sieve, adding an ethanol solution, adding acid to adjust the PH value to be 2-3, adding a biological enzyme after one hour, performing enzymolysis in a double-frequency ultrasonic device, filtering, adjusting the PH value of the filtrate to be 10.0 by using concentrated ammonia water, extracting with ethyl acetate, collecting an organic phase, drying with anhydrous sodium sulfate, filtering, performing vacuum concentration till the materials are dried, dissolving with a small amount of ethanol, and purifying in a silica gel column chromatography manner, thereby obtaining the high-purity vincaleukoblastinum. The novel method has the advantages of simple process, high extraction rate and high product purity, and is applicable to industrialization production.

The invention discloses a double-frequency ultrasonic transducer and ultrasonic detection equipment. The double-frequency ultrasonic transducer comprises a low-frequency unit and a high-frequency unit; the low-frequency unit and the high-frequency unit share a backing layer, the low-frequency unit further comprises a low-frequency flexible circuit board layer, a low-frequency piezoelectric layer and a low-frequency matching layer, and the high-frequency unit further comprises a high-frequency flexible circuit board layer, a high-frequency piezoelectric layer and a high-frequency matching layer; or, the low-frequency unit and the high-frequency unit share the backing layer and a flexible circuit board layer at the same time, the flexible circuit board layer annularly wraps the periphery ofthe backing layer, the low-frequency unit further comprises a low-frequency piezoelectric layer and a low-frequency matching layer, and the high-frequency unit further comprises a high-frequency piezoelectric layer and a high-frequency matching layer. The double-frequency ultrasonic transducer is provided with the low-frequency unit and the high-frequency unit which can independently emit low-frequency ultrasonic waves and high-frequency ultrasonic waves, and the low-frequency unit and the high-frequency unit can work separately or simultaneously and do not interfere with each other; and the function of low-frequency and high-frequency ultrasonic detection can be realized, and the characteristic of small size can be obtained.

The invention provides a novel acousto-optic catalytic water purification device and a working method thereof. The novel acousto-optic catalytic water purification device is characterized in that an ultrasonic source, a light source, an acousto-optic catalyst adding port and an acousto-optic catalyst intercepting and recycling channel are arranged in the device; and a reaction tank is connected with a water inlet channel, a water outlet channel and a blow-off pipe. A main body part of the device is composed of an acousto-optic catalytic reactor and a secondary cross-flow filtration reaction membrane; (1) the acousto-optic catalytic reactor achieves the purpose of acousto-optic catalytic degradation of pollutants; (2) ultrasonic transducers of the adopted ultrasonic field are divided into two groups, the adopted ultrasonic field is a double-frequency ultrasonic field, the purpose of adopting double frequencies is to enable sound waves to generate the superposition phenomenon, vibrationwaves with larger amplitude are generated in the sound wave diffusion process, and the increase of the number and types of cavitation bubbles is promoted; and (3) the concentration polarization of themembrane filtration material is reduced through cross-flow filtration, the membrane operation time is prolonged, and meanwhile, the catalyst is retained in the reactor through membrane filtration, sothat the loss of the catalyst is avoided.

The present invention discloses maca fruit and vegetable drink and a preparation method thereof, and belongs to the technical filed of fruit and vegetable drink processing. The provided maca fruit and vegetable drink contains 30 parts of maca extract solution, 40 parts of apple juice, 20 parts of tomato juice, 8 parts of white granulated sugar, 0.18 part of citric acid, 0.08 part of essence and 1.74 parts of pure water. A pH of the drink is 3.2-3.4. At the same time, the present invention also provides a maca fruit and vegetable drink preparation method. The provided method uses a dual-frequency ultrasound alternately enhanced supercritical fluid extraction technology to extract the active ingredients in the maca, the drink is high in extraction rate, the nutrients are not easily be damaged, and the drink is high in purity, free of solvent residues, free of pollutions, etc.

The invention discloses an ice cream production method and an ice cream machine. After entering the ice cream machine from a feeding pipe, ice cream is congealed through a refrigerant; the ice cream is treated orthogonally by two different groups of ultrasonic waves, namely the ice cream starts to be nucleated for 3 minutes when the material temperature is negative 1 DEG C-negative 3 DEG C along with the ultrasonic action intensity being 0.8-1 W / cm<2> and the total power being 230 W; and the ice cream starts to perform phase transition when the material temperature is negative 3 DEG C-negative6 DEG C along with the ultrasonic action intensity being 1-1.2W / cm<2>, the total power being 250W and the ultrasonic treatment time being 12 minutes. Air is introduced into the freezing cavity through an air compressor and is mixed with raw materials of ice cream, orthogonal double-frequency ultrasonic wave can assist congelation, so that the cavitation effect is remarkable, the ice cream congelation efficiency is remarkably improved, the formed ice crystals and bubbles are smaller but distributed more uniform, a secondary sterilization effect is formed, and the taste and quality of the ice cream are better.

The invention relates to a method for extracting Chinese fevervine herb volatile oil. The method is characterized by comprising the following steps: uniformly mixing and homogenizing rhizome of Chinese fevervine herb and a 60-70 percent ethanol solution of which the weight is 1-2 times that of medicinal materials in a homogenizer, and extracting for 10-15 minutes; adding 3-4 times of 60-70 percent ethanol after homogenizing, extracting by adopting dual-frequency ultrasonic waves at the ultrasonic power of 400-600W, continuously extracting at the temperature of 60-70 DEG C for 90-120 minutes, filtering, and concentrating the filtrate until alcohol taste is eliminated; and extracting the concentrated solution for 2-3 times by using an organic solvent, merging the extracting solutions, drying through anhydrous sodium sulfate, performing vacuum concentration, and obtaining the Chinese fevervine herb volatile oil. The method is simple in operation, short in extraction time and high in yield and is suitable for industrial production.

The invention relates to a blind guiding device and a blind guiding method based on dual-frequency ultrasonic waves. The blind guiding device structurally comprises a control handle, a control press key, a main circuit board, a first ultrasonic wave emitting energy transducer, a second ultrasonic wave emitting energy transducer, a first ultrasonic wave receiving energy transducer and a second ultrasonic wave receiving energy transducer; the control handle is mainly provided with a storage battery; and a main control circuit is arranged inside the main circuit box, and can be used for resolving ultrasonic wave signals with the corresponding frequency received by the first ultrasonic wave receiving energy transducer and the second ultrasonic wave receiving energy transducer and controlling a warning device to send out the warning alarm according to the resolving result so as to tell the distance and the moving state of obstacles to a blind person. The blind guiding method provided by the invention can be used for helping the blind person to judge the moving state of the obstacles in advance on the basis of detecting the distance of the obstacles, and has the advantages that the precision is high; the operation is simple; and the electricity is saved, and the like.