imiyalelo Yila i-ECG eSebenzayo ngoCwangciso oluzenzekelayo lwe-Biosignal
Yila i-ECG eSebenzayo ngoCwangciso oluzenzekelayo lwe-Biosignal
Le projekthi idibanisa yonke into efundiweyo kule semester kwaye iyisebenzise kumsebenzi omnye. Umsebenzi wethu kukudala isekethe ekwaziyo ukusetyenziswa njenge-electrocardiogram (ECG) ngokusebenzisa izixhobo zombane. ampi-lifier, i-lowpass filter, kunye ne-notch filter. I-ECG isebenzisa i-electrodes ebekwe kumntu ukulinganisa nokubonisa umsebenzi wentliziyo. Ubalo lwenziwa ngokusekwe kumndilili wentliziyo yabantu abadala, kwaye ischematics sesekethe sokuqala zenziwe ngeLTSpice ukungqinisisa inzuzo kunye nokunqunyulwa kwamaza. Iinjongo zale projekthi yoyilo zezi zilandelayo:
- Sebenzisa izakhono zezixhobo ezifundwe elebhu kwesi siqingatha sonyaka
- Yila, wakhe, kwaye uqinisekise ukusebenza kwesixhobo sokufumana umqondiso
- Qinisekisa isixhobo kumxholo womntu
Izibonelelo:
- I-LTSpice simulator (okanye isoftware efanayo) Ibhodi yesonka
- Abaxhamli abahlukeneyo
- Ii-capacitors ezahlukeneyo
- Opamps
- Iingcingo ze-Electrode
- Igalelo voltagUmthombo
- Isixhobo sokulinganisa umthamo wemvelisotage (oko kukuthi i-oscilloscope)
Inyathelo loku-1: Yenza izibalo zeCandelo leSekethe nganye
Le mifanekiso ingasentla ibonisa izibalo zesekethe nganye. Ngezantsi, icacisa ngakumbi malunga namacandelo kunye nokubalo okwenziwe.
Izixhobo zomculo Ampisihlanguli
Isixhobo ampi-lifier, okanye i-IA, inceda ukubonelela ngesixa esikhulu senzuzo kwiimpawu ezisezantsi. Inceda ukwandisa ubungakanani bomqondiso ukuze ibonakale ngakumbi kwaye i-waveform inokuhlalutywa.
Ukubala, sikhethe amaxabiso amabini angakhethiyo e-resistor e-R1 kunye ne-R2, eyi-5 kΩ kunye ne-10 kΩ, ngokulandelanayo. Sifuna kwakhona ukuba inzuzo ibe yi-1000 ngoko umqondiso uya kuba lula ukuhlalutya. Umlinganiselo we-R3 kunye ne-R4 usonjululwa ngolu hlobo lulandelayo:
IVout / (Vin1 – Vin2) = [1 + (2*R2/R1)] * (R4/R3) –> R4/R3 = 1000 / [1 + 2*(10) / (5)] –> R4/ I-R3 = 200
Emva koko sasebenzisa loo mlinganiso ukugqiba ukuba ixabiso ngalinye le-resistor liya kuba yintoni. Amaxabiso ami ngolu hlobo lulandelayo:
I-R3 = 1 kΩ
Isihluzo seNotshi
Isihluzi senotshi sithomalalisa imiqondiso phakathi kwebhanti emxinwa yefrikhwensi okanye sisuse ifrikhwensi enye. Amaxesha esifuna ukuwasusa kule meko ngama-60 Hz kuba uninzi lwengxolo eveliswa zizixhobo zombane ikweso sihlandlo. I-AQ factor ngumlinganiselo we-frequency center ukuya kwi-bandwidth, kwaye ikwanceda ukuchaza imilo yeploti yobukhulu. Umba omkhulu we-Q ukhokelela kwibhendi yokumisa emxinwa. Ukubala, siza kusebenzisa ixabiso le-Q lika-8.
Sagqiba ekubeni sikhethe amaxabiso e-capacitor esinawo. Ngoko ke, C1 = C2 = 0.1 uF, kunye neC2 = 0.2 uF.
Ii-equations esiza kuzisebenzisa ukubala i-R1, i-R2, ne-R3 zezi zilandelayo:
I-R1 = 1 / (4*pi*Q*f*C1) = 1 / (4*pi*8*60*0.1E-6) = 1.6 kΩ
R2 = (2*Q) / (2*pi*f*C1) = (2*8) / (2*pi*60*0.1E-6) = 424 kΩ
I-R3 = (R1*R2) / (R1 + R2) = (1.6*424) / (1.6 + 424) = 1.6 kΩ
Isihluzi seLowpass
Isihluzi sokudlula esisezantsi sithomalalisa iifrikhwensi eziphezulu ngelixa sivumela iifrikhwensi ezisezantsi ukuba zidlule. I-cutoff frequency iya kuba nexabiso le-150 Hz kuba lixabiso elichanekileyo le-ECG kubantu abadala. Kwakhona, inzuzo (ixabiso le-K) iya kuba yi-1, kwaye i-constants a kunye ne-b yi-1.414214 kunye ne-1, ngokulandelanayo.
Sikhethe i-C1 ukuba ilingane ne-68 nF kuba sinaloo capacitor. Ukuya kwi-C2 sisebenzise le nxaki ilandelayo:
C2 >= (C2*4*b) / [a^2 + 4*b(K-1)] = (68E-9*4*1) / [1.414214^2 + 4*1(1-1)] –> C2 >= 1.36E-7
Ngoko ke, sikhethe uC2 ukuba alingane no-0.15 uF
Ukubala amaxabiso amabini aphikisayo, kuye kwafuneka sisebenzise ezi zibalo zilandelayo:
R1 = 2 / (2*pi*f*[a*C2 + sqrt([a^2 + 4*b(K-1)]*C2^2 – 4*b*C1*C2)] = 7.7 kΩ
I-R2 = 1 / (b*C1*C2*R1*(2*pi*f)^2) = 14.4 kΩ
Inyathelo loku-2: Yenza i-Schematics kwi-LTSpice
Omathathu amacandelo enziwe kwaye aqhutywa ngokwahlukeneyo kwi-LTSpice ngohlalutyo lokutshayela lwe-AC. Amaxabiso asetyenzisiweyo ngalawo sibale kwinyathelo loku-1.
Inyathelo loku-3: Yakha Isixhobo AmpUtyikitye
Sakha isixhobo sokudlala ampi-lifier kwi-breadboard ngokulandela isikimu kwi-LTSpice. Nje ukuba yakhiwe, igalelo (tyheli) kunye nesiphumo (luhlaza) voltages zaboniswa. Umgca oluhlaza unenzuzo kuphela ye-743.5X xa kuthelekiswa nomgca ophuzi.
Inyathelo loku-4: Yakha iNotch Filter
Emva koko, sakhe isihluzi se-notch kwi-breadboard esekwe kwisicwangciso esenziwe kwi-LTSpice. Yakhiwe ecaleni kwesekethe ye-IA. Emva koko sarekhoda igalelo kunye nemveliso yevoltagU-e uxabisa kwiifrikhwensi ezahlukeneyo ukumisela ubungakanani. Emva koko, senze igraphi ubukhulu vs. frequency kwiploti ukuyithelekisa nokulinganisa kweLTSpice. Ekuphela kwento esiyitshintshileyo yayizixabiso ze-C3 kunye ne-R2 eziyi-0.22 uF kunye ne-430 kΩ, ngokulandelelanayo. Kwakhona, i-frequency eyisusayo yi-60 Hz.
Inyathelo loku-5: Yakha iLowpass Filter
Emva koko sakha isihluzo sokupasa esisezantsi kwi-breadboard esekwe kwisikimu kwi-LTSpice ecaleni kwesihluzi senotshi. Emva koko sirekhode igalelo kunye nomthamo wemvelisotagkwiifrikhwensi ezahlukeneyo ukumisela ubungakanani. Emva koko, saceba ubukhulu kunye nokuphindaphinda ukuthelekisa kunye nokulinganisa kwe-LTSpice. Ekuphela kwexabiso esilitshintshileyo kwesi sihluzo yi-C2 eyi-0.15 uF. I-cutoff frequency ebesiyiqinisekisa yi-150 Hz.
Inyathelo loku-6: Uvavanyo Kumbandela Woluntu
Okokuqala, qhagamshela amacandelo amathathu omntu ngamnye wesekethe kunye. Emva koko, yivavanye ngesingqi sentliziyo esifanisiweyo ukuqinisekisa ukuba yonke into iyasebenza. Emva koko, beka i-electrodes kumntu ngamnye ukuze i-positive ibe kwisandla sasekunene, i-negative ikwi-ankle ekhohlo, kwaye umhlaba ukwi-ankle yasekunene. Nje ukuba umntu sele elungile, qhagamshela ibhetri ye-9V ukunika amandla i-opamps kwaye ubonise isignali yemveliso. Qaphela ukuba umntu kufuneka ahlale ethule kakhulu malunga nemizuzwana eyi-10 ukuze afunde ngokuchanekileyo.
Sivuyisana nawe, wenze ngempumelelo i-ECG ezenzekelayo!
Amaxwebhu / Izibonelelo
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imiyalelo Yila i-ECG eSebenzayo ngoCwangciso oluzenzekelayo lwe-Biosignal [pdf] Imiyalelo Yila i-ECG eSebenzayo ngoCwangciso oluzenzekelayo lwe-Biosignal, yila i-ECG eSebenzayo, i-ECG eSebenzayo, ukuPlating kwe-Biosignal |
