High-frequency Electrical Stimulation Nerve Block And The Design Of Blocking Signal Generator

If the signals in the neurons are abnormal, body will feel uncomfortable or be disabled for acting. Such abnormal signals are conducted to sensory centre and effectors through the nerve pathways, so if the nerve pathway is damaged, the conduction of these abnormal signals will be blocked. The process is called nerve block.Nowadays, the ways of blocking are mainly divided into chemical blocking and physical blocking. Chemical blocking methods consist of the use of local anesthetic drugs and the use of nerve damaging drugs.Physical blocking ways are divided into compression, heating, cooling, mechanical injury, etc.All of the physical ways are harmful to nerves.The administration of local anesthetic drugs is the most mature way, but the way may have some side effects, and the duration of the treating effect is short. While the other blocking ways have a damage effect on the nervous, and may result in external trauma. High-frequency electrical stimulation block is a new technique that can overcome these shortcomings, and owns the advantages of specific ,reversible, unharmful characteristic.This paper investigated the blocking effect of high frequency AC signal tonerve action potential conduction. Frog sciatic nerve was dissected out in the experiments. The amplitude of action potential(AP) and the state of muscle during high-frequency sinusoidal stimulation were observed to determine the blocking effect. The results showed that in a certain frequency complete block could be achieved at the threshold. When the stimulation amplitude increased upon threshold there was no obvious difference in the character of the block. With an increase in frequency, block threshold also increased. The muscle tetanus due to the block frequency stimulation vanished after a short period signals ,which frequency is higher than the block frequency were induced. In the following course, the muscle status is according to the AP of the innervation nerve.In order to facilitate further research, this project has designed a sinusoidal signal generator. The generator can output the sinusoidal signal the frequency and amplitude of which can be adjusted.The frequency is controlled by the PC software,while the amplitude is determined by the magnification factor of operational amplifier.The system's core technology is the DDS (Direct Digital Synthesis). Compared to the direct analog synthesis and the indirect lock-type synthesis,the DDS technology has many advantages, including a relatively wide bandwidth, high frequency resolution, frequency switching speed, continuous phase, low noise of the output signal, programmable, easy to integrate digital technology, small size, light weight and so on.This study will explore new ways for clinical anesthesia, analgesia, and toantispasmodic.