【正文】 achieve an accurate point of this design is the simple and precise of the need to measure the pulse of the human body in one minute,and to ensure that the error in less than 2 times..The whole system is center on singlechip microputer 89s51,using the signlechip to achieve the system core function of counting the frontend of the signal, we use piezoelectric ceramics to collect the signal of the human body then,after after amplification of the AD620, shaping of the 555, filtering of the lowpass filter and other operations,the signal will be converted to the pulse signal with the same frequency,and this signal will be input to the singleship will count to method of counting is using the timer of the singleship,and then use the cycle,get the frequency,by the frequency,we can get the number of the oneminute pulse. The final result of the count will display in the 1602 LCD the performance of the piezoelectric ceramics is not very good,in the signal can’t do it very its price is very low,and after the signal conditioning circuit of the system,the signal can be quite satisfactory to achieve our objectives. At the beginning of the paper, the integral notion of the device design is brought out. Afterwards, the detail information of each part is narrated. At last part, some suggestions for improving the device are provided. Key words: Pulse measurement。系統(tǒng)運(yùn)行中能顯示脈搏次數(shù)和時(shí)間，系統(tǒng)停止運(yùn)行時(shí)，能夠顯示總的脈搏次數(shù)和時(shí)間。計(jì)數(shù)結(jié)果將最終送至液晶屏 1602 來進(jìn)行顯示。在信號的前端處理上，使用壓電陶瓷片采集人體脈搏信號，然后經(jīng)過 AD620 放大，施密特觸發(fā)器整形， 低通濾波器濾波等一系列操作，將脈搏信號轉(zhuǎn)換為同頻率的脈沖信號輸入到單片機(jī)內(nèi)，并利用單片機(jī)對其進(jìn)行計(jì)數(shù)。系統(tǒng)測量出人體一分鐘的脈搏，并且保證誤差在 2 次以內(nèi)。由于脈搏信號的特殊性，在設(shè)計(jì)時(shí)必須要注意實(shí)現(xiàn)測量的準(zhǔn)確。 基于單片機(jī)的人體脈搏檢測系統(tǒng)設(shè)計(jì) 摘要 脈搏波所呈現(xiàn)出來的形態(tài)、強(qiáng)度、速率和節(jié)律等方面的綜合信息，能反映出人體心血管系統(tǒng)中許多生理疾病的血流特征。 本課題是人體脈搏測量儀的設(shè)計(jì)。該系統(tǒng)的重點(diǎn)就在于要求實(shí)現(xiàn)測量的簡便化和精確化。本系統(tǒng)以89S51 單片機(jī)作為中心，通過使用單片機(jī)來實(shí)現(xiàn)系統(tǒng)最核心的計(jì)算脈搏功能。計(jì)數(shù)的方法是利用單片機(jī)的計(jì)時(shí)器，然后由該周期計(jì)算出頻率，繼而就可以求出一分鐘的脈搏數(shù)。雖然壓電陶瓷片的性能并非很好，在信號的采集上不能實(shí)現(xiàn)非常精確的采集，但是它的價(jià)格低廉，并且在經(jīng)過系統(tǒng)的信號調(diào)理電路后，也能比較滿意的實(shí)現(xiàn)我們所要實(shí)現(xiàn)的目標(biāo)。 本文首先描述本設(shè)計(jì)的整體思路，然后介紹各個(gè)部分設(shè) 計(jì)中的細(xì)節(jié)問題，最后提出一些完善本設(shè)計(jì)的改進(jìn)意見。 piezoelectric ceramics。 singleship 第 1 頁 共 2 頁 目 錄 1 緒論 ................................................................................................................................ 1 課題背景及目的 ...................................................................................................... 1 國內(nèi)外研究狀況及發(fā)展趨勢 .................................................................................. 2 課題研究難點(diǎn) .......................................................................................................... 3 抗干擾 ............................................................................................................ 3 低噪聲、低漂移 ............................................................................................ 3 課題主要研究內(nèi)容 .................................................................................................. 4 2 系統(tǒng)總體設(shè)計(jì) ................................................................................................................ 5 系統(tǒng)硬件電路設(shè)計(jì)方案 .......................................................................................... 6 傳感器的選擇 ................................................................................................. 6 單片機(jī)的選擇 ................................................................................................ 8 信號調(diào)理電路的選擇 .................................................................................... 9 系統(tǒng)軟件設(shè)計(jì)方案 ................................................................................................ 10 脈搏波動頻率測量方案的選擇 .................................................................. 10 單片機(jī)工作方式的選擇 .............................................................................. 10 顯示電路方案的選擇 .................................................................................. 11 3 系統(tǒng)硬件設(shè)計(jì) .............................................................................................................. 11 一級放大電路的設(shè)計(jì) ............................................................................................ 12 二階濾波器電路的設(shè)計(jì) ........................................................................................ 14 第二級放大電路的設(shè)計(jì) ........................................................................................ 17 整形電路 ................................................................................................................ 18 定時(shí)計(jì)數(shù)電路的設(shè)計(jì) ............................................................................................ 21 顯示電路的設(shè)計(jì) .................................................................................................... 22 4 系統(tǒng)軟件設(shè)計(jì) .............................................................................................................. 25 第 2 頁 共 2 頁 主程序流程的設(shè)計(jì) ................................................................................................ 25 定時(shí)器 /計(jì)數(shù)器中斷程序流程的設(shè)計(jì) ................................................................... 26 顯示程序流程的設(shè)計(jì) ............................................................................................ 27 5 總結(jié)與展望 .................................................................................................................. 28 參考文獻(xiàn) .......................................................................................................................... 29 致謝 .................................................................................................................................. 31 附錄 .................................................................................................................................. 32 附錄 A 原理圖 ............................................................................................................. 32 附錄 B 主程序 ............................................................................................................. 33 附錄 C 顯示程序 .......................................................................................