Design of High Electric Potential Therapy Equipment
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【Author in Chinese】 高铁旦；
【Author's Information】 南方医科大学， 生物医学工程， 2013， 硕士
【Abstract】 With the lifestyle changing, the pressure of living increasing, the state of environment declining, as well as our population aging, sub-health and chronic diseases have become recognized as the important reasons that harm people’s health. According to statistics, the number of the patients with chronic diseases in china has arrived at260million. It is not only a serious threat to the health and lives of the residents, but also a heavy economic burden of the patients and their family, becoming an ignored current social problem.High potential therapy applied in clinical medicine has a long history, as early as the18th century in some countries of the Europe and the United States, which was restricted latter, due to the equipment and technology. In the later of1920s, Dr.Yuan Minzi, a Japanese scientist, set out to study the Ac high voltage potential therapeutic apparatus and succeeded with the body load experiment which made some patients with chronic disease got effective treatment, marking this ancient electric therapy had been a remarkable development. The whole body is in an AC high voltage electric field during high potential therapy to produce a therapeutic effect on the human body. The Ac high potential therapy has also been referred to as a high voltage therapy in Ac electricity, which is similar to the nature electric field to influence the physiological functions of the human body (especially the function of the nervous system and the metabolic system), achieving the therapeutic purposes.It possesses of many biophysical properties:First, there exists an electric field around the object with charges. The free charges of a conductor placed in a potential field move quickly to the two poles of the electric field, so that the conductor ends to induced charge. When the human body is under the high potential in the field of the high voltage potential, the membrane potential of the body is changed and the organization produce weak current with0.1～0.2mA, making part of the charged cells with sufficient vigor. Second, the dipolar molecules with negative or positive charges will change in polarity in the electrolyte, when the body in the field of high voltage potential. The dipole arranged regularly again according to the direction of the positive polarity attracting each other, while they originally arranged messily. The protein in the body fluids will be oriented to the direction of the electric field and the polarization charges are added to its respective zwitterionic pole (induced dipoles), then the charges in whole body will be increased, thereby generating a series of biological effect. Third, the air produce a large amount of air ions due to the high voltage potential filed. Patient can feel good as the breeze is winding around him, which is a similar subtle air ion flow sensor to the skin massage stimulation reactions. According to Paharohauf" study and the clinical experiments, we discovered that the electric wind have a good effect on the slow-healing wounds and ulcers, when they are partially subjected to wind. Forth, the air produce ozone due to the high voltage potential filed. The ozone content in the air that patient breathe is0.0014～0.00148mg·L during the high potential therapy. As we all know, ozone can irritate strongly the neural system. It not only effects on the respiratory system but also on the electricity and gas metabolism etc through the blood circulation. Ozone is an unstable gas, easily reduced to release the active oxygen, is an oxidizing agent, and contributes to the sterilization and promotes the wound healing. Ozone can raise the blood levels of oxidized hemoglobin content and reduction, at the same time can increases the number of red blood cells in the blood.High potential therapy can increase the tissue cell viability and the cell membrane permeability, can adjust the fluid electrolyte and acid-base balance, strengthen the body’s natural immune system and improve the natural healing ability, repair the tissue cell in the sub-healthy or which has been diseased by acting on the various systems of the body such as the nervous system, endocrine system, the humoral-systemic etc, organs and tissue cells. Finally the human body system and organ function get improved and enhanced. It is proved that High Electrical Potential Therapy Equipment has curative effect on a variety of chronic diseases, through various animal and human experiments both in China and abroad, as well as years of clinical practice.High potential therapy equipment is one of treatment equipments owe to the high voltage electric field, including power frequency electric field, intermediate frequency electric field, and the negative potential electric field. The output of the high potential therapeutic apparatus in this article is the power frequency electric field.The high potential therapeutic apparatus in this paper takes ATmega1280-16AU AVR microcontroller as controller, which has128KB of Flash space,86general-purpose I/O interface, and a wealth of other on-chip resources, fast working, and superior performance.24064dot matrix display, as a man-machine interface, drivers chip T6963C. It is convenient to drive, as well as low-cost. Its customers base for the elderly, so the machine uses key as a control input. The intensity of light has a great impact for users to observe the display. The machine uses light sensor for real-time detection of the intensity of light around. The machine automatically brightens the backlight of the display; vice versa. In addition, the machine is equipped with an infrared remote control, which is convenient to the user to operate it within a certain distance.This device consists of systemic and local output ports, equipped with insulation pad, electronic pen, sleeping mats, high-voltage wire, electric fitting cushion, foot pedal. It has four treatment modes such as systemic mode, local mode, sleep mode and fixed mode. The Insulating pad segregates the human body from the earth, so that the body is insulated. The high voltage applied to the human body will only have a very weak current. The electronic pen and sleep pad are used in conjunction with local output port, while sleep pad is used with sleep mode and the electronic pen with local treatment mode. The electric fitting cushion and foot pad joint the systemic output port and are used in conjunction with the systemic mode and the fixed mode. When this device is in the state of systemic treatment model, it has a negative peak voltage selection from3000V,7000V,9000V,14000V. The four output waveforms of each output voltage can choose the treatment time of15minutes,30minutes,45points,60points. It automatically cycle through a combination of systemic treatment mode every5minutes. According to the different treatment time, there are three or four combinations while each combination is the combination of one of the four output voltages and the four output waveforms. When this device is in the state of local treatment model, its negative peak of voltage has three selections from1100V,1700V,2100V. Every output voltage has three kinds of waveforms. The treatment time is15minutes fixedly. It automatically changes the output waveform every5minutes. When the device is in the state of sleep treatment mode, its output voltage has a fixed negative peak of1100V and the treatment time can adjust from15minutes to8hours. It automatically loop the output waveform every5minutes with the treatment time changing. The fixed treatment mode is similar with the systemic treatment mode for they have the same output voltage and waveform. However the device automatically changes the combination every5minutes as the program set, as well as the treatment time is60minutes fixedly.High potential therapeutic apparatus belongs to class III in the national medical device registration management classification. The device would be called class I device if its electric shock protection not only relies on basic insulation but also on the fixed wiring with additional safety precautions which makes the metal where can be touched not charged even insulation fails. The device would be called class II device if its electric shock protection not only relies on basic insulation but also on double insulation or reinforced insulation with additional safety precautions without protective earth measures, and not depends on the installed condition. The high potential therapeutic apparatus in this article belongs to class I equipment according to the electric shock protection classification.A kind of medical equipment named high potential therapeutic apparatus, due to the particularity of itself, should be paid attention to its characteristics in the design and specification. It is strictly limited the range, the way, the object to use in the specification. It should be insulated from the earth and is prohibited to use if the patient has implanted medical devices inside or has wear ECG measurement equipment. Moreover, the patient who has obvious abnormal state should consult the doctor to make sure whether the equipment can be used. For actual treatment of the potential therapeutic apparatus can be changed along with environmental factors such as voltage, size, location and distance of the electrodes, humidity in the air, the open circuit voltage is used to measure the performance metrics of the device. The error of the output voltage is within±10%which can satisfy requirements of the use in performance and equipment safety.The treatment principle of equipment is applying high voltage in human body to produce high voltage AC electric field around. Although the equipment is used in insulation condition, it is still needed to make sure that the risks don’t occur in the non-insulation condition when the patient is in unconscious. Thereby it is needed to limit output power of the device. To ensure the safety of the patients, it is necessary to string a13MΩ protective impedance network in the output circuit to strictly limit short circuit current value. The output current is monitored timely. When the output current is greater than the threshold set in advance, the output current changes automatically and the alarm works, which protects users better with the protective impedance network. To coincide with actual production, testing, and registered, we drafted the corresponding product standard and clinical plan. As this device has passed through experiments and got experts’ratification, we conclude that the high potential therapeutic apparatus is in line with the expected design specifications, and meets the requirements of the relevant standards. At the end of this article, we not only discuss the related work of this high potential therapeutic equipment, but also look to the future work.