| Hypertension is the most common chronic disease in the world,and it is also the first risk factor for cardiovascular and cerebrovascular diseases.The accompanying complications endanger human health seriously.At present,hypotensor are always used as a treatment for high blood pressure.Long-term use of hypotensor is costly and the complications may cause inconvenience to patients with hypertension.Because of the disadvantages of using hypotensor as the sole therapy for hypertension,researchers began to seek non-drug treatment.Studies have shown that regularly reducing the respiratory rate of the human body can increase the sensitivity of heart rate variability and baroreceptor,so as to lower blood pressure.The blood pressure depressor based on slow breathing designed in this paper combined with medical electronics technology,sensor technology,and biofeedback principles.The breathing frequency of body is used as the feedback to guide the patients to reduce the breathing gradually through visual and auditory signals,so as to reduce the blood pressure according to slow breathing theory.The design and improvement of hardware and software of the blood pressure depressor was finished in this paper,at the same time,relative test of the device and volunteers experiment was carried out.For hardware design,the breath detection sensor,the liquid crystal circuit,the audio circuit,the main control circuit,the power supply circuit,the data storage the keyboard circuit and so on were realized in this paper.The sensor adopts a variable distance capacitance breathing detection sensor.The basic principle is that the chest / abdomen fluctuating movement leads to the change of capacitance when the human body is breathing,and the change of capacitance changes to get the respiratory wave signal.The STM32F103RCT6 chip is used as the main controller,and the working mode of the buck meter is designed.The audio module was designed using WM8978 chip based on demand.For display,LCD12864 lattice module was used to make it convenient for the middle-aged and elderly patients to watch.FLASH module was used to store and protect key data in the case of power loss;power module including external power supply and lithium battery power supply were adopted to distribute the power supply voltage of different modules to reduce overall power consumption.For the software,the optimization of the slow breathing guiding algorithm was finished on the basis of previous study after investigating relative reports.An interaction interface with audiovisual effects was designed to guide the patients adjust their inhalation and exhalation indirectly using music rhythm and graphic change indications,and finally Slow down the respiration rate of the subjects and achieve the effect of lowering blood pressure.Finally,the designed device meet the safety requirements of the instrument including current leakage and electrolyte strength of the buck gauge according to the safety test in GB 9706.1-2007.31 volunteers were recruited to carry out the auxiliary blood pressure training experiment.The results of the experiment were analyzed statistically.The preliminary results show that the system can effectively guide the patients with hypertension to carry out slow breathing training to help reduce the effect of blood pressure,and there is no abnormal accident and adverse reaction in the process of use. |
