| Preoperative anxiety is an unhealthy state of anxiety caused by a patient's fear of suffering from pain,suffering from sequelae,or even death before undergoing surgical treatment.Excessive anxiety will affect the doctor's use of anesthetic drugs,and increase the patient's reliance on analgesic pump after surgery,and extend the time of discharge.Research shows that transcutaneous electric acupoint stimulation(TEAS)can be used to transmute opioid concentration in the blood,increase activity of vagus nerve and parasympathetic nerve,and induce brain in transacupuncture at Shenmen and Erxin.The alpha wave of radio waves regulates the internal bioelectricity of the human body and plays a role in replenishing heart and spleen,tranquilizing nerves,calming and analgesia,soothing muscles,relaxing nerves,lowering blood pressure and heart rate,etc.,so as to alleviate preoperative anxiety.Based on the above-mentioned medical mechanism,this design carried out a systematic demand analysis,and based on this as a basis for the implementation of hardware and software,developed a pre-operative anxiety smart music low-frequency pulse therapy instrument.On the hardware,the instrument's main control chip selects a single chip highly integrated ATmega128,and the power circuit selects BOOST boost chopper circuit to boost the 12 V input to 100 V to ensure that an effective conduction current is formed at the patient's acupuncture point.At the same time,the voltage series negative feedback circuit is designed in conjunction with the LM358 chip,and with the D/A conversion circuit,the instrument is strictly current-limited at the same time as the constant current output.The stimulating main circuit is designed as an H-bridge circuit to achieve positive and negative symmetric bipolar pulse waveform output.This design innovatively combines TEAS therapy with music therapy,adding a music player module that uses VS1003 as the decoding chip.In addition,this design adds a temperature monitoring circuit to the instrument to supplement the monitoring of body temperature.The instrument is equipped with a 12864 LCD screen and six independent buttons for user convenience.In order to filter out the higher harmonics in the SPWM output,the design uses a normalized LPF method to design a second-order low-pass filter,and a large number of simulations using Saber software to determine the output waveform meets the requirements.In software,this design is based on the function of the instrument and the modules are designed in various modules.Use ATmega128's phase correction PWM mode,combined with Matlab software to help calculate the duty cycle,the final output SPWM with sine law.This design is based on the working principle and timing relationship of TLC5615,DS18B20,VS1003,12864 LCD,using ICCAVR compiler to design the D/A conversion current limit,temperature monitoring,audio decoding,liquid crystal display and key scan and other procedures.After completing the construction of the hardware and software platform,this study used a power supply,oscilloscope,multimeter and other equipment to conduct experiments on prototypes and tested their output.40 primary gynecological patients were selected for preliminary clinical trials in the hospital,and sedation scores were calculated using Remsay.Tables and other methods evaluated the efficacy of this design.The results showed that the Ramsay sedation score was increased,the BIS value was decreased,and the heart rate decreased after the patient received physiotherapy.This proves that the smart music low-frequency pulse therapy device designed in this study can produce obvious anxiety-relieving effects,with good economic benefits and social benefit. |
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