Design of Living Beings Electrotherapy Instrument System

Abstract

A low frequency living beings electrotherapy instrument is designed which is based on the transcutaneous electrical nerve stimulation. This system uses ATmega32 (MCU) to control its output and display. The hardware part includes the keyboard, the LCD, the alarm circuit and output circuit .The other part is software, which includes keyboard module, LCD module, pulse creating module and so on. The human-computer interaction can be realized well by the keyboard and LCD module. The pulse creating module controls the frequency, the duty-ratio and time of treatment. Introduction In the area of treatment, physical therapy is a common method of treatment. It is wide application because of the course of treatment without pain, little side effects and significant effect on certain diseases. Investigation shows that the fixed frequency signal is long applied to the stimulation of the human body, the signal will weaken the effect of the human body treatment . Therefore, it is significant for the stimulation of the body that the output signal frequency is independent, which can be well adapted to overcome the ability of human tissue, make the patient obtain the optimal therapeutic effect. The output signal of traditional physical therapy instrument has a certain regularity, which can make the body produce the adaptability and reduce the effect. The core of living beings electrotherapy instrument is the output signal waveform generation module, which relies on Atmega32 to achieve. The PWM module of Atmega32 can control the shape, frequency and amplitude of the output signal, and the output waveform can be generated randomly, applicable symptoms. The system can well solve the shortage of traditional electrotherapy instrument system, such as the treatment of adaptability of output signal, polarization voltage smaller, patient comfort and simple operation etc.. Therefore, it has a certain practical value to research and development of living beings electrotherapy. Electrotherapy principle The human body is a good conductor of electricity, has certain conductivity. During the treatment, the pulse current is applied to the deep body tissues and stimulate tissue to produce a variety of regular and irregular shrinkage . Such action by the organization can reduce the pain sensation, promote parts of the organization metabolism, but also has anti-inflammatory, removing blood stasis, adjusting the endocrine and metabolic disorders, improving local tissue blood circulation, eliminating excess fat, dredging the channel and other effects [3] . The pulse signal frequency is lower than 1000Hz is defined as the low frequency signal in medicine. The use of low frequency electrical stimulation of tissue to recuperate the body way is referred to as low frequency electrotherapy. Low frequency electrical signals applied to human tissue, stimulates the human tissue, which can accelerate the blood flow of partial tissue and alleviate the pain. Treatment principle of the system is based on transcutaneous electrical nerve stimulation therapy .The low frequency electrical signal is inputted to the human body by the skin and plays a role in healing and alleviate pain, which is known as TENS. TENS is widely used clinically, which can promote the local blood circulation, alleviate the pain and promote the development of bones. International Conference on Materials, Environmental and Biological Engineering (MEBE 2015) © 2015. The authors Published by Atlantis Press 448 People know about more the pain mechanism along with the progress of electronic and medical knowledge and the improving of people living conditions. Firstly the meridian theory thinks that the disease occurrence and development are related the acupoints of main and collateral channels. Later, the research indicates that the main and collateral channels and acupoints have the characteristic of potential high and low impedance and the impedance can change when the electrical signal effects them, which can make the human body appear acid, hemp, pain, swelling and other physiological phenomena. Therefore, the meridian and points which can reflect the function of muscle tissue, organ or physical condition should be chosen, the potential of the body can quickly restore balance, the meridian smooth, and the body is healthy by imposing its corresponding pulse signal. The overall design of the system The structure diagram of the system is shown in figure 1. It mainly consists of two parts: based on the ATmega32 control circuit and PWM interface circuit. The core of the control circuit is ATmega32, which has abundant resources and general equipment interface and includes key module, LCD module, PWM output module, sampling module, alarm module. The PWM Interface circuit includes filter circuit and power amplifier circuit. Atmage32 ADC LCD interface Keyboard interface PWM output display module Keyboard module alarm module signal sampling output circuit electrode