Ultrasonic waves:
Ultrasonic therapeutics is an important part of ultrasound medicine. Ultrasound therapy when the ultrasound energy will be applied to the diseased parts of the body, in order to achieve the purpose of treating the disease and promoting the recovery of the organism.
In the world, ultrasound is widely used in diagnostics, therapeutics, engineering, biology and other fields. Safari home ultrasound therapy machine belongs to the use of ultrasound therapeutics.
(A) engineering applications: underwater positioning and communications, underground resource exploration, etc.
(B) biological applications: shear macromolecules, bioengineering and treatment of seeds, etc.
(C) diagnostic applications: A-type, B-type, M-type, D-type, dual-performance and color ultrasound, etc.
(D) therapeutic applications: physical therapy, cancer treatment, surgery, body lithotripsy, ultrasound, ultrasound, ultrasound, ultrasound, ultrasound, ultrasound, ultrasound, and so on.
Features of ultrasound:
1. Ultrasound wave propagates in a strong direction, and the energy is easy to concentrate.
2, ultrasonic waves can be propagated in a variety of different media, and can be propagated far enough distance.
3, the interaction between ultrasound and sound transmission medium is moderate, easy to carry information about the state of the sound transmission medium (diagnosis or effect on the sound transmission medium. (Treatment)
Ultrasonic wave is a form of fluctuation, it can be used as a carrier or medium for detecting and loading information (such as B ultrasound used as a diagnostic); ultrasound at the same time is a form of energy, when its intensity exceeds a certain value, it can be through the interaction of the medium with the propagation of ultrasonic waves, to affect, change or destroy the latter's state, nature and structure (used as a therapeutic).
History of the development of ultrasound:
I. International:
Since the end of the 19th century to the beginning of the 20th century, the discovery of the piezoelectric effect and the anti-piezoelectric effect in physics, after the discovery of the piezoelectric effect, people solved the use of electronics to produce ultrasound, and since then quickly opened the development and popularization of ultrasound technology of the history of the chapter.
In 1922, Germany appeared the first ultrasound therapy invention patent.
In 1939, the literature published on the clinical effects of ultrasound treatment.
The late 40's ultrasound therapy in Europe and the United States, until the first international medical ultrasound conference held in 1949, there is ultrasound therapy paper exchanges for the development of ultrasound therapy laid the foundation for the second international ultrasound conference in 1956, there have been a number of papers published, ultrasound therapy has entered the practical stage of maturity.
Second, the domestic side:
Domestic in the field of ultrasound therapy started a little late in the early 1950s, only a few hospitals to carry out ultrasound therapy, from 1950, first began to use 800KHz frequency ultrasound therapy in Beijing to treat a variety of diseases, to the 50's began to gradually promote, and have a domestic instrument. Public literature reports were first published in 1957. By the 1970s, there were various types of domestic ultrasound therapeutic instrument, ultrasound therapy popularized in large hospitals across the country.
Over the past 40 years, the country's major hospitals have accumulated a considerable amount of information and relatively rich clinical experience. In particular, the emergence of ultrasound extracorporeal mechanical wave lithotripsy and ultrasound surgery in the early 1980s was a major breakthrough in the history of stone disease treatment. Nowadays, it has been popularized and applied internationally. High-intensity focused ultrasound noninvasive surgery has made ultrasound therapy occupy an important position in contemporary medical technology. And in the 21st century (HIFU) ultrasound focused surgery has been hailed as the latest technology for the treatment of tumors in the 21st century.
Mechanism of ultrasound treatment:
1. Mechanical effect: the effect of ultrasound in the medium forward. (Ultrasound propagation in the medium is produced by reflection and mechanical effects) it can cause a number of body reactions. Ultrasound vibration can be caused by the movement of substances within the tissue cells, due to the ultrasound micro-massage, so that the cell plasma flow, cell shock, rotation, friction, thus producing the role of cell massage, also known as the "internal massage" This is the unique characteristics of ultrasound therapy can change the permeability of the cell membrane, stimulate the diffusion of cellular semi-permeable membrane process, promote the metabolism, accelerate blood and lymphatic flow, and promote the development of the body. Metabolism, accelerate blood and lymph circulation, improve cell ischemia and hypoxia, improve tissue nutrition, change the rate of protein synthesis, improve regeneration function. Make changes in the internal structure of the cell, resulting in functional changes in the cell, so that the hard connective tissue extension, flaccid.
The mechanical action of ultrasound can soften tissues, enhance penetration, improve metabolism, promote blood circulation, stimulate the nervous system and cellular functions, thus having the unique therapeutic significance of ultrasound.
2. Thermal effect: the human body tissue has a relatively large absorption capacity of ultrasound energy, so when the ultrasound in the human body tissue propagation process, its energy is constantly absorbed by the tissue into the heat, the result is that the organization's own temperature rise.
Heat generation process is both mechanical energy in the medium into heat energy conversion process. That is, endogenous heat. Ultrasound warming effect can increase blood circulation, accelerate metabolism, improve local tissue nutrition, enhance enzyme activity. In general, the thermal effect of ultrasound to bone and connective tissue is significant, fat and blood for the least.
3. Physical and chemical effects: the mechanical and thermal effects of ultrasound can promote a number of physical and chemical changes. It has been proved that some physical and chemical effects are often the secondary effects of the above effects. TS-C-type therapy machine through the physical and chemical effects of the following five secondary effects:
A. Dispersive effect: ultrasound can improve the permeability of biological membranes, ultrasound, the cell membrane of potassium, calcium ions after the effect of strong changes in permeability. Thus, it enhances the diffusion process of biofilm, promotes material exchange, accelerates metabolism, and improves tissue nutrition.
B. Thixotropic effect: Under the action of ultrasound, the gel can be transformed into a sol-gel state. The softening effect on muscle, tendon, and some pathological changes related to tissue dehydration. Such as rheumatoid arthritis lesions and the treatment of degenerative lesions of joints, tendons and ligaments.
C. Cavitation: cavitation is formed, either by unidirectional vibration that remains stable, or secondary to swelling to the point of collapse, with altered cellular function and increased intracellular calcium levels. Fibroblasts are activated, protein synthesis increases, vascular permeability increases, angiogenesis is accelerated, and collagen tension increases.
D. Polymerization and depolymerization: water molecule polymerization is the process of synthesizing multiple identical or similar molecules into one larger molecule. Macromolecular depolymerization is the process of turning a large chemical molecule into a smaller one. It can lead to increased hydrolase and proenzyme activity in the joints.
E. Anti-inflammatory, repair of cells and molecules: the ultrasound effect can make the tissue PH value to the alkaline side. Relieves local acidosis associated with inflammation. Ultrasound can affect blood flow, produce inflammation-causing effects, inhibit and play an anti-inflammatory role. Mobilizes leukocytes and promotes angiogenesis. Collagen synthesis and maturation. Promotes or inhibits the repair and healing process of damage. This results in the process of cleaning, activating and repairing damaged cells and tissues.
The transducer converts the ultrasonic frequency electrical energy into mechanical vibration and radiates ultrasonic waves through the wall of the cleaning tank to the cleaning liquid contained in the tank. Existing in the liquid micro-bubbles (known as cavitation nuclei) in the role of sound waves vibration, when the sound pressure or sound intensity reaches a certain value, the rapid growth of bubbles, and then suddenly closed. In the bubble closure, shock waves, around the bubble to produce 1012 ~ 1013Pa pressure and local high temperature, this physical phenomenon is called ultrasonic cavitation. The huge pressure generated by cavitation can destroy the insoluble dirt and make them dispersed in the solution. Steam-type cavitation on the dirt layer of direct repeated impact, on the one hand, to destroy the dirt and cleaning parts of the surface of the adsorption, on the other hand, will also cause fatigue damage to the dirt layer and detachment. Gas-type bubble vibration on the solid surface scrubbing, dirt layer once there are cracks to drill, bubbles can also be "drilled" into the cracks for vibration, so that the dirt layer off. Due to cavitation, the two liquids at the interface quickly dispersed and emulsified, when the solid particles are wrapped in oil and adhering to the surface of the cleaning parts, the oil is emulsified, the solid particles fall off by themselves. Ultrasonic propagation in the cleaning fluid will produce positive and negative alternating acoustic pressure, impact cleaning parts, and at the same time due to the nonlinear effect will produce acoustic flow and micro-acoustic flow, and ultrasonic cavitation in the solid and liquid interfaces will produce high-speed micro-jet, all of which can damage the dirt to remove or weaken the boundary layer of dirt to increase the mixing, diffusion, accelerate the dissolution of soluble dirt, strengthen the cleaning effect of the chemical cleaning agent. Visible from the citation, wherever the liquid can be dipped into, the presence of sound field are cleaning effect, and cleaning speed, high quality, especially for cleaning parts of the surface shape of complex, such as cavities, slits and other detailed cleaning, easy to realize the cleaning automation. On some occasions, you can use water instead of organic solvents for cleaning, or reduce the concentration of acid and alkali, for some damage to human health cleaning, such as cleaning radioactive dirt can be realized by remote control or automated cleaning. Ultrasonic cleaning also has its limitations, such as sound reflection of strong materials such as metal, ceramics and glass cleaning effect is good, while the sound absorption of large materials such as fabric, rubber and viscosity of the dirt cleaning effect is poor.
Ultrasonic cleaning began in the early 1950s of this century, with the advancement of technology applications are expanding. Currently has been widely used in the electronics industry, cleaning semiconductor devices, tube parts, printed circuits, relays, switches and filters, etc.; machinery industry for cleaning gears, bearings, oil pumps and oil nozzles coupling, fuel filters, valves and other mechanical parts, such as the engine and missile parts, such as watch parts; in the optics and medical equipment used to clean a variety of lenses, eyeglasses and frames, medical In the optical and medical equipment used to clean a variety of lenses, glasses and frames, medical glassware, syringes and surgical instruments, etc.; used in the textile industry to clean the spinneret, food bottles, caps, molds and carving crafts and so on.
The above examples of ultrasonic cleaning, generally with 20 ~ 40kHz low-frequency ultrasound, in recent years the United States developed a technology called Megasonic cleaning, that is, 1MHz high-frequency ultrasound to clean large-scale integrated circuits, can remove less than 1μm of dirt, the cleaning mechanism is not ultrasonic cavitation, but mainly particle velocity and acoustic flow. In the 90's the United States Crest claimed that they invented the 68kHz ultrasonic cleaning floppy disk drive, the efficiency is twice as high as using 40kHz.
China's ultrasonic cleaning in the following aspects of the more effective application:
1) mechanical parts in the plating before and after the cleaning or spraying before the cleaning, dismantling and repairing parts cleaning. Require a high degree of cleanliness such as oil pump oil nozzle coupling, bearing cleaning.
2)Printed circuit boards, silicon wafers, signal control relays for railroad systems, components, picture tubes and electro-vacuum devices and other cleaning.
3) microscopes, telescopes and other optical systems and sampling glass pieces of cleaning.
4)Medical instruments such as oral and surgical instruments cleaning, medicine bottles and some food bottles, dispensing room, biochemistry laboratory used in the cleaning of bottles and jars.
5)Cleaning of spinnerets, eyeglass frames, molds, carving crafts, etc.
Recently developed ultrasonic cleaning of automobile chassis frame, with a special cleaning solution, will remove rust, oxide film and phosphating a cleaning process is completed, drying can be sprayed with paint, to overcome the past artificial rubbing rust, strong acid cleaning process features, both to improve labor conditions and reduce environmental pollution.
Ultrasonic cleaning equipment has two major categories: one is an aqueous solution as a cleaning agent equipment, such equipment, including ultrasonic frequency power source, ultrasonic transducer and the corresponding ultrasonic containers and electric heaters; one is a single-slot type, the other is a multi-tank (multi-station) continuous cleaning equipment, often with timing and automatic conveyor. Another type is to volatile organic solutions, such as trichloroethylene, trichloroethane and freon as a cleaning agent, this type of equipment in addition to the above components, but also need to have a condensation cycle, oil and water separation and filtration to recover the organic solution of additional equipment. At present, the main domestic and foreign production and development of a variety of specialized cleaning equipment, online production of complete sets of equipment. Also produces desktop, compact cleaning equipment, such as medical cleaner and small jewelry glasses home cleaner.
Ultrasonic frequency is generally 20 ~ 50kHz, small equipment, the electric power of only a few days, large-scale complete sets of equipment up to dozens of kilowatts to hundreds of kilowatts. Ultrasound transducer 50 ~ 60 years most of the magnetostrictive transducer, most of the current use of high-efficiency piezoelectric transducer; ultrasound frequency electric power source in the past with tube devices, has been eliminated and the use of solid-state devices, with the device produced by high efficiency and small size, the use of the combined structure, the power can be made very large for the expansion of high-power ultrasound applications to create a good condition.
The United States production of ultrasonic cleaning equipment, there are about 40 companies, the more famous about 10, Western European countries to produce cleaning equipment is mainly Britain, France, Germany and Switzerland and other countries. China's ultrasonic cleaning equipment, the main manufacturers of about 10, small-scale individual companies countless.
Foreign manufacturers pay much attention to the supply of chemical cleaning agents and cleaning process consulting services, which is the majority of domestic manufacturers are most lacking, the domestic manufacturers mainly consider the production of ultrasonic cleaning equipment, few specialized departments engaged in the development of cleaning agents to adapt to the needs of different cleaning objects. If the ultrasonic cleaning equipment and chemical cleaning agents will be a good combination of better results, because the main physical mechanism of ultrasonic cleaning is ultrasonic cavitation phenomenon, and cavitation strength in addition to ultrasonic power density, frequency and other related to the viscous coefficient of the cleaning fluid, surface tension, vapor pressure and temperature and other parameters. At present, from the perspective of environmental protection requirements to water-based cleaning agent instead of organic solvents for ultrasonic cleaning, and many domestic manufacturers have not yet been able to adapt to this challenge, but also the need for a variety of cooperative development.