Nā mea aʻoaʻo E hoʻolālā i kahi ECG Hana Me ka Hoʻolālā Automated o ka Biosignal
E hoʻolālā i kahi ECG hana me ka hoʻolālā ʻokoʻa o ka Biosignal
Hoʻohui kēia papahana i nā mea a pau i aʻo ʻia i kēia kau a hoʻohana ʻia i hoʻokahi hana hoʻokahi. ʻO kā mākou hana ka hana ʻana i kahi kaapuni i hiki ke hoʻohana ʻia ma ke ʻano he electrocardiogram (ECG) me ka hoʻohana ʻana i nā mea kani. amplifier, kānana ala haʻahaʻa, a me ka kānana notch. Hoʻohana ka ECG i nā electrodes i kau ʻia ma luna o ke kanaka e ana a hōʻike i ka hana o ka naʻau. Ua helu ʻia ma muli o ka awelika o ka puʻuwai kanaka makua, a ua hana ʻia nā schematics kaapuni kumu ma LTSpice e hōʻoia i ka loaʻa a me ka ʻoki ʻana i nā alapine. ʻO nā pahuhopu o kēia papahana hoʻolālā penei:
- E hoʻohana i nā mākau mea kani i aʻo ʻia ma ka lab i kēia kau
- E hoʻolālā, kūkulu, a hōʻoia i ka hana o kahi mea lawe hōʻailona
- E hōʻoia i ka hāmeʻa ma ke kumuhana kanaka
Mea lako:
- LTSpice simulator (a i ʻole nā polokalamu like) Breadboard
- Nā mea pale like ʻole
- capacitors like ʻole
- Opamps
- Uea uila
- Hoʻokomo voltage kumuwaiwai
- Mea hana e ana i ka voltage (ie oscilloscope)
KaʻAnuʻu 1: Hana i ka helu no kēlā me kēia ʻāpana kaapuni
Hōʻike nā kiʻi ma luna i nā helu no kēlā me kēia kaapuni. Ma lalo iho, wehewehe hou aku e pili ana i nā ʻāpana a me nā helu i hana ʻia.
Mea hana Ampmea mālama ola
He mea kani amplifier, a i ʻole IA, kōkua i ka hāʻawi ʻana i ka nui o ka loaʻa no nā hōʻailona haʻahaʻa. Kōkua ia i ka hoʻonui ʻana i ka nui o ka hōʻailona no laila e ʻike ʻia a hiki ke nānā ʻia ke ʻano nalu.
No ka helu ʻana, ua koho mākou i ʻelua mau kumu kūʻai kūʻokoʻa no R1 a me R2, ʻo ia ka 5 kΩ a me 10 kΩ. Makemake mākou i ka loaʻa ʻana he 1000 no laila e maʻalahi ka hōʻailona e nānā. Hoʻoholo ʻia ka ratio no R3 a me R4 e ka hoohalike penei:
Vout / (Vin1 – Vin2) = [1 + (2*R2/R1)] * (R4/R3) -> R4/R3 = 1000 / [1 + 2*(10) / (5)] -> R4/ R3 = 200
A laila ua hoʻohana mākou i kēlā ratio e hoʻoholo ai i ka waiwai o kēlā me kēia resistor. ʻO nā waiwai penei:
R3 = 1 kΩ
Kānana Notch
Hoʻopau ka kānana notch i nā hōʻailona i loko o kahi ʻāpana haiki o nā alapine a i ʻole e wehe i kahi alapine hoʻokahi. ʻO ke alapine a mākou e makemake ai e wehe i kēia hihia ʻo 60 Hz no ka mea ʻo ka hapa nui o ka leo i hana ʻia e nā mea uila ma ia alapine. ʻO ka helu AQ ka ratio o ke alapine waena i ka bandwidth, a kōkua pū kekahi i ka wehewehe ʻana i ke ʻano o ka pā nui. Loaʻa ka helu Q nui aʻe i kahi hui kū haiki. No ka helu ʻana, e hoʻohana mākou i ka waiwai Q o 8.
Ua hoʻoholo mākou e koho i nā waiwai capacitor i loaʻa iā mākou. No laila, C1 = C2 = 0.1 uF, a me C2 = 0.2 uF.
ʻO nā hoohalike a mākou e hoʻohana ai no ka helu ʻana iā R1, R2, a me R3 penei:
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
R3 = (R1*R2) / (R1 + R2) = (1.6*424) / (1.6 + 424) = 1.6 kΩ
Kānana Lowpass
Hoʻemi ka kānana ala haʻahaʻa i nā alapine kiʻekiʻe me ka ʻae ʻana i nā alapine haʻahaʻa e hele. He 150 Hz ka waiwai o ka alapine ʻoki ʻoki no ka mea ʻo ia ka waiwai ECG kūpono no nā pākeke. Eia kekahi, ʻo ka loaʻa (k value) he 1, a ʻo nā mea mau a me b he 1.414214 a me 1.
Ua koho mākou iā C1 e like me 68 nF no ka mea ua loaʻa iā mākou kēlā capacitor. No ka nd C2 ua hoʻohana mākou i ka hoohalike penei:
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
No laila, koho mākou iā C2 e like me 0.15 uF
No ka helu ʻana i nā koina resistor ʻelua, pono mākou e hoʻohana i kēia mau hoohalike:
R1 = 2 / (2*pi*f*[a*C2 + sqrt([a^2 + 4*b(K-1)]*C2^2 – 4*b*C1*C2)] = 7.7 kΩ
R2 = 1 / (b*C1*C2*R1*(2*pi*f)^2) = 14.4 kΩ
KaʻAnuʻu 2: E hana i nā Schematics ma LTspice
Ua hana ʻia nā ʻāpana ʻekolu a holo pākahi ma LTSpice me kahi loiloi AC sweep. ʻO nā waiwai i hoʻohana ʻia ʻo ia nā mea a mākou i helu ai ma ka ʻanuʻu 1.
KaʻAnuʻu 3: E kūkulu i ka mea hana Ampʻāpau
Ua kūkulu mākou i ka mea kani amplifier ma ka papa palaoa ma ka hahai ʻana i ka schematic ma LTSpice. I ka manawa i kūkulu ʻia ai, ʻo ke komo (melemele) a me ka puka ('ōmaʻomaʻo) voltagua hōʻike ʻia. ʻO ka laina'ōmaʻomaʻo wale nō ka loaʻa o 743.5X i hoʻohālikelikeʻia me ka laina melemele.
KaʻAnuʻu 4: E kūkulu i ka kānana Notch
A laila, kūkulu mākou i ka kānana notch ma ka papa palaoa e pili ana i ka schematic i hana ʻia ma LTSpice. Ua kūkulu ʻia ma ka ʻaoʻao o ke kaapuni IA. A laila hoʻopaʻa mākou i ka voltage helu i nā alapine like ʻole e hoʻoholo ai i ka nui. A laila, kiʻi mākou i ka magnitude vs. frequency ma ka pākuʻi e hoʻohālikelike iā ia i ka simulation LTSpice. ʻO ka mea wale nō a mākou i hoʻololi ai, ʻo ia ka waiwai o C3 a me R2, ʻo ia ka 0.22 uF a me 430 kΩ. Eia hou, ʻo 60 Hz ka alapine e hoʻoneʻe ai.
KaʻAnuʻu 5: E kūkulu i ke kānana Lowpass
A laila kūkulu mākou i ka kānana haʻahaʻa haʻahaʻa ma ka papa palaoa e pili ana i ka schematic ma LTSpice ma hope o ka kānana notch. A laila hoʻopaʻa mākou i ka voltagi nā alapine like ʻole e hoʻoholo ai i ka nui. A laila, hoʻolālā mākou i ka nui a me ke alapine e hoʻohālikelike ai i ka simulation LTSpice. ʻO ka waiwai wale nō a mākou i hoʻololi ai no kēia kānana ʻo C2 ʻo ia ka 0.15 uF. ʻO ka alapine cutoff a mākou e hōʻoia nei ʻo 150 Hz.
KaʻAnuʻu 6: Hoao ma ke kumuhana kanaka
ʻO ka mua, e hoʻohui i nā ʻāpana ʻekolu o ke kaapuni. A laila, e hoʻāʻo iā ia me ka puʻuwai simulated e hōʻoia i ka holo ʻana o nā mea a pau. A laila, kau i nā electrodes ma luna o kēlā me kēia kanaka no laila aia ka maikaʻi ma ka lima ʻākau, ʻaʻole i ka wāwae hema, a ʻo ka lepo ma ka wāwae ʻākau. Ke mākaukau ke kanaka, hoʻohui i kahi pākaukau 9V e hoʻoikaika i ka opamps a hōʻike i ka hōʻailona puka. E hoʻomaopopo pono e noho mālie ke kanaka no kahi o 10 kekona e loaʻa ai ka heluhelu pololei.
Hoʻomaikaʻi, ua hana maikaʻi ʻoe i kahi ECG automated!
Palapala / Punawai
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Nā mea aʻoaʻo E hoʻolālā i kahi ECG Hana Me ka Hoʻolālā Automated o ka Biosignal [pdf] Na kuhikuhi E hoʻolālā i kahi ECG hana me ka hoʻolālā ʻokoʻa o ka biosignal, e hoʻolālā i kahi ECG hana, ECG hana, e hoʻolālā i ka biosignal. |
