Design Of Respiratory Monitoring Apparatus Base On MCU PIC16F877

The breath is an important parameter that reflects the human body function, which hasvery important reference value in the life ward of the human body. Within the scope of certain,normal various physiology parameter index of the human body can keep the dynamic balance.The organism passes various feedback approaches to keep one's stabilization of variousimportant functions, being in the normal state. Because of disease or the reasons that can'tresist make several physiology indexes outrun the natural scope, the feedback affect to otherphysiology functions, and the organism will sink into the vicious cycle appearance, and thecondition is rapid to aggravate until the life crock up. Therefore, we measure accurately theperson's respiratory signal and reflect the respiratory signal with the variety of time, whichhave the important meaning for the clinical medical science.With the development of electronics technique, Micro Controller Unit general applies tothe instrument field owing to the small volume, the strong function, the low power consuming.According to current technique and development direction, we designed and researched theproject of respiratory monitoring apparatus base on MCU PIC16F877. It cans actually theperson's breath of monitor of hour, consecution, and long time. Our work studied the wholeprocess that the respiratory signal withdraws, and we make use of sensor to convert therespiratory signal into electric signal. After amplifying and filtering, the respiratory signal issent into computer to the real time show from MCU control.Because MCU output TTL electricity, we need to design the conversion circuit in thecommunication course of MCU and computer. The conversion circuit can transmit the databetween the different electricity. In the paper, the computer's serial interface is accessed to theMSComm control in VB6.0, adopting the asynchronous communication with MCU. We editassembler of communications and A/D conversion in the bottom developing. Thesuperstratum interfaces are designed with VB6.0. It can examine and show the respiratorysignal, and set communication port simply by asking. It has realistic meaning.