Tsis siv neeg ECG- BME 305 Qhov Kawg Kawg Qhov Nyiaj Ntxiv: 7 Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:24

Ib qho electrocardiogram (ECG lossis EKG) yog siv los ntsuas cov teeb liab hluav taws xob uas tsim los ntawm lub plawv dhia thiab nws ua lub luag haujlwm tseem ceeb hauv kev kuaj mob thiab ua rau muaj kab mob plawv. Qee cov ntaub ntawv tau txais los ntawm ECG suav nrog kev sib dhos ntawm tus neeg mob lub plawv dhia ntxiv rau lub zog ntawm kev ntaus. Txhua qhov ECG waveform tau tsim los ntawm kev rov ua dua ntawm lub plawv dhia. Cov ntaub ntawv raug sau los ntawm hluav taws xob tso rau ntawm daim tawv nqaij ntawm tus neeg mob. Lub teeb liab tom qab ntawd tau nthuav dav thiab lub suab nrov tau lim tawm txhawm rau txheeb xyuas cov ntaub ntawv tam sim no. Siv cov ntaub ntawv uas khaws cov kws tshawb fawb tuaj yeem tsis tsuas yog kuaj mob kab mob hauv lub plawv, tab sis ECG kuj tseem ua lub luag haujlwm loj hauv kev nce kev nkag siab thiab lees paub ntau yam kab mob tsis meej pem. Kev siv ECG tau txhim kho zoo heev rau kev kho mob xws li arrhythmia thiab ischemia [1].

Khoom siv:

Cov Lus Qhia no yog rau simulating lub cuab yeej ECG virtual thiab yog li ntawd txhua yam uas xav tau los ua qhov kev sim no yog lub computer ua haujlwm. Lub software siv rau qhov kev sim hauv qab no yog LTspice XVII thiab nws tuaj yeem rub tawm los ntawm is taws nem.

Kauj Ruam 1: Kauj Ruam 1: Kev ntsuas qhov ntsuas

Thawj qhov tivthaiv hauv Circuit Court yog qhov ntsuas qhov ntsuas. Raws li lub npe qhia, cov cuab yeej siv suab nrov tau nce ntxiv qhov loj ntawm lub teeb liab. Ib qho ECG teeb liab uas tsis ua kom nrov nrov lossis lim tawm yog kwv yees li 5 mV hauv qhov dav. Txhawm rau lim lub teeb liab, nws yuav tsum tau nthuav dav. Qhov tsim nyog tau txais txiaj ntsig rau qhov kev sib tw no yuav tsum yog qhov loj kom lub teeb liab hluav taws xob tau raug lim dej kom tsim nyog. Yog li ntawd, qhov tau txais ntawm qhov kev sib tw no yuav yog txog 1000. Daim ntawv dav dav ntawm cov cuab yeej ntsuas qhov ntsuas tau suav nrog hauv cov duab rau theem no [2]. Ntxiv rau qhov sib npaug rau qhov tau txais ntawm Circuit, qhov txiaj ntsig uas tau suav rau txhua qhov kev tiv thaiv tau qhia hauv daim duab thib ob [3].

Qhov tau txais yog qhov tsis zoo vim tias qhov hluav taws xob tau muab rau tus pin inverting ntawm lub tshuab ua haujlwm ua haujlwm. Cov txiaj ntsig tau qhia hauv daim duab thib ob tau pom los ntawm kev teeb tsa qhov tseem ceeb ntawm R1, R2, R3, thiab nce raws li qhov xav tau thiab tom qab ntawd daws qhov txiaj ntsig zaum kawg R4. Cov duab thib peb rau cov kauj ruam no yog simulated Circuit hauv LTspice, ua tiav nrog qhov muaj tseeb.

Txhawm rau ntsuas lub Circuit Court, ob qho tag nrho thiab tag nrho cov khoom ib leeg, yuav tsum muaj kev tshuaj xyuas tam sim no (AC). Daim ntawv txheeb xyuas no saib qhov loj ntawm lub teeb liab raws li qhov hloov pauv zaus. Yog li, kev txheeb xyuas hom kev txheeb xyuas AC yuav tsum yog kaum xyoo vim tias nws teev cov x-axis ntsuas thiab muaj txiaj ntsig ntau dua rau kev nyeem qhov raug. Ib xyoo caum, yuav tsum muaj 100 cov ntsiab lus cov ntaub ntawv. Qhov no yuav qhia meej txog cov kev hloov pauv hauv cov ntaub ntawv yam tsis muaj kev ua haujlwm dhau los, kom ntseeg tau qhov ua tau zoo. Qhov pib thiab nres qhov zaus zaus yuav tsum suav nrog ob qho kev txiav tawm zaus. Yog li, qhov tsim nyog pib zaus yog 0.01 Hz thiab qhov tsim nyog siv ceev yog 1kHz. Rau qhov ntsuas qhov ntsuas, qhov ua haujlwm tawm yog sine wave nrog qhov loj ntawm 5 mV. 5 mV sib haum nrog tus qauv dav ntawm ECG teeb liab [4]. Lub sine yoj ua raws qhov hloov pauv ntawm ECG teeb liab. Tag nrho cov teeb tsa kev tshuaj xyuas no, tshwj tsis yog rau qhov hluav taws xob nkag, yog tib yam rau txhua feem.

Cov duab kawg yog cov lus teb zaus rau qhov ntsuas qhov ntsuas. Qhov no qhia tau hais tias qhov ntsuas qhov ntsuas tau tuaj yeem ua kom qhov loj ntawm cov teeb liab nkag los ntawm kwv yees li 1000. Qhov xav tau nce rau qhov ntsuas qhov ntsuas yog 1000. Qhov nce ntawm qhov ntsuas qhov ntsuas qhov ntsuas yog 999.6, pom siv cov zauv uas pom hauv daim duab thib ob. Qhov feem pua yuam kev ntawm qhov xav tau nce thiab qhov kev sim nce yog 0.04%. Qhov no yog qhov lees paub qhov feem pua yuam kev.

Kauj Ruam 2: Kauj Ruam 2: Ntiv Dej Lim

Cov khoom siv tom ntej siv hauv ECG Circuit Court yog cov lim dej ua haujlwm. Lub lim dej ua haujlwm tsuas yog lub lim dej uas xav tau lub zog txhawm rau ua haujlwm. Txog txoj haujlwm no, lub lim dej zoo tshaj plaws uas yuav tsum tau siv yog lub ntsej muag lim. Lub taub lim dej siv los tshem tawm cov teeb liab ntawm ib zaus lossis qhov nqaim heev ntawm cov zaus. Hauv qhov xwm txheej no, qhov zaus yuav raug tshem tawm nrog lub ntsuas phoo lim yog 60 Hz. 60 Hz yog qhov zaus uas cov kab hluav taws xob ua haujlwm ntawm thiab yog li ntawd yog lub suab nrov loj nrog cov khoom siv. Powerline lub suab nrov cuam tshuam cov teeb meem biomedical thiab txo qhov ua tau zoo ntawm cov ntaub ntawv [5]. Daim ntawv dav dav ntawm lub ntsej muag lim siv rau hauv Circuit Court no tau qhia hauv thawj daim duab rau theem no. Qhov tivthaiv nquag ntawm lub hauv paus lim yog qhov tsis tuaj yeem txuas nrog. Qhov tsis yog siv los cais cov teeb liab tom qab lub thais lim Txij li qhov tsis yog ib feem ntawm lub lim dej thiab nws xav tau lub zog los ua haujlwm, lub thais lim yog cov lim dej ua haujlwm tseem ceeb ntawm qhov Circuit no.

Qhov sib npaug rau qhov tiv thaiv thiab cov khoom siv hluav taws xob ntawm cov lim dej thais tau qhia hauv daim duab thib ob [6]. Hauv qhov sib npaug, fN yog qhov yuav tsum tau tshem tawm, uas yog 60 Hz. Raws li qhov ntsuas qhov ntsuas, yog tus tiv thaiv lossis tus nqi hluav taws xob tuaj yeem teeb tsa tus nqi thiab lwm tus nqi suav los ntawm qhov sib npaug uas tau qhia hauv daim duab thib ob. Rau lub lim dej no, C tau muab tus nqi 1 µF thiab qhov seem ntawm qhov txiaj ntsig tau pom los ntawm tus nqi ntawd. Tus nqi ntawm lub capacitor tau txiav txim siab raws qhov yooj yim. Cov lus hauv daim duab thib ob qhia txog qhov tseem ceeb ntawm 2R, R, 2C, thiab C uas tau siv.

Cov duab thib peb rau cov kauj ruam no yog qhov kawg ntawm lub tshuab lim lim nrog qhov raug. Siv qhov kev sib tham ntawd, AC Sweep tsom xam tau siv 5V. 5V sib haum nrog qhov hluav taws xob tom qab ua kom nrov nrov. Tus so ntawm qhov ntsuas ntsuas tsis zoo ib yam li tau hais hauv kauj ruam ntsuas qhov ntsuas qhov ntsuas. Cov lus teb cov lus teb tau pom hauv daim duab kawg. Siv qhov tseem ceeb thiab kev sib npaug hauv daim duab thib ob, qhov tseeb zaus rau lub ntsuas phoo lim yog 61.2 Hz. Tus nqi xav tau rau lub ntsej muag lim yog 60 Hz. Siv qhov feem pua yuam kev sib npaug, muaj 2% yuam kev nruab nrab ntawm cov lim simulated thiab lim theoretical. Qhov no yog qhov lees paub qhov ua yuam kev.

Kauj Ruam 3: Kauj Ruam 3: Tsawg Pass Lim

Hom kawg ntawm ib feem siv hauv Circuit no yog lub lim dej lim dej. Raws li tau hais yav dhau los, lub lim dej lim yog lub lim dej uas tsis xav tau lub zog siv los ua haujlwm. Rau ECG, ob qho kev nkag siab thiab lim qis dhau yog xav tau kom tshem tawm suab nrov ntawm lub teeb liab. Thawj hom passive lim uas yuav muab ntxiv rau hauv Circuit Court yog lim qis. Raws li lub npe qhia, qhov no ua ntej tso cai rau hauv qab qhov txiav tawm zaus kom dhau [7]. Rau qhov lim qis dhau, qhov txiav tawm zaus yuav tsum yog txwv qis tshaj ntawm qhov ntau ntawm cov teeb liab. Raws li tau hais dhau los, qhov ntau ntawm ECG teeb liab yog 150 Hz [2]. Los ntawm kev teeb tsa qhov txwv siab tshaj plaws, suab nrov los ntawm lwm cov cim qhia tsis tau siv hauv kev teeb liab.

Qhov sib npaug rau kev txiav tawm zaus yog f = 1 / (2 * pi * R * C). Raws li nrog cov khoom siv hluav taws xob yav dhau los, qhov muaj txiaj ntsig rau R thiab C tuaj yeem pom los ntawm kev ntsaws hauv qhov zaus thiab teeb tsa ib qho ntawm cov khoom sib xyaw [7]. Rau qhov lim qis dhau, lub ntsuas hluav taws xob tau teeb tsa ntawm 1 µF thiab qhov xav tau txiav tawm zaus yog 150 Hz. Siv qhov txiav tawm qhov sib npaug zaus, tus nqi rau cov tiv thaiv tiv thaiv tau suav ua 1 kΩ. Thawj daim duab rau theem no yog ua tiav qhov qis qis lim lim.

Tib yam tsis tau teev tseg rau lub ntsej muag lim tau siv rau AC Sweep Analysis ntawm cov lim qis dhau, qhia hauv daim duab thib ob. Rau qhov kev tivthaiv no, qhov xav tau txiav tawm zaus yog 150Hz thiab siv Tshooj 3, kev sim txiav tawm zaus yog 159 Hz. Qhov no muaj feem pua yuam kev ntawm 6%. Feem pua yuam kev rau cov khoom siv no siab dua qhov nyiam tab sis cov khoom siv tau raug xaiv kom yooj yim ntawm kev txhais lus rau lub cev muaj zog. Qhov no tau hais meej qhov lim qis dhau, raws li cov lus teb cov lus pom hauv daim duab thib ob, tsuas yog lub teeb liab hauv qab qhov txiav tawm zaus tuaj yeem hla ntawm 5 V, thiab raws li qhov nce mus rau qhov txiav tawm zaus, qhov hluav taws xob qis.

Kauj Ruam 4: Kauj Ruam 4: Siab Dhau Lim

Qhov kev tiv thaiv thib ob rau ECG Circuit Court yog lub siab lim lim. Lub siab dhau lim yog lim uas tso cai rau txhua zaus ntau dua li qhov txiav tawm kom dhau mus. Rau qhov tivthaiv no, kev txiav tawm zaus yuav yog 0.05 Hz. Ib zaug ntxiv 0.05 Hz yog qhov qis kawg ntawm qhov ntau ntawm ECG cov cim [2]. Txawm hais tias tus nqi me me, tseem yuav tsum muaj lub siab lim lim txhawm rau lim tawm qhov hluav taws xob tawm hauv lub teeb liab. Yog li ntawd, lub siab dhau lim tseem tsim nyog nyob hauv kev tsim hluav taws xob, txawm hais tias kev txiav tawm zaus tsawg heev.

Qhov sib npaug rau kev txiav tawm zaus yog tib yam li qhov qis dhau txiav tawm lim, f = 1 / (2 * pi * R * C). Tus nqi tiv thaiv tau teeb tsa rau 50 kΩ thiab qhov xav tau txiav tawm zaus yog 0.05 Hz [8]. Siv cov ntaub ntawv ntawd, tus nqi hluav taws xob tau suav rau 63 µF. Thawj daim duab rau cov kauj ruam no yog lim siab dhau nrog cov txiaj ntsig tsim nyog.

AC Sweep Analysis yog lub lim thib ob. Zoo li cov lim qis dhau, raws li qhov zaus ntawm lub teeb liab mus rau qhov txiav tawm zaus, qhov tso tawm hluav taws xob tsawg dua. Rau qhov lim siab dhau, qhov xav tau txiav tawm zaus yog 0.05 Hz thiab qhov simulated txiav tawm zaus yog 0.0505 Hz. Tus nqi no tau xam siv qhov qis dhau txiav tawm qhov sib npaug zaus. Qhov feem pua yuam kev rau qhov tivthaiv no yog 1%. Qhov no yog qhov feem pua lees paub yuam kev.

Kauj Ruam 5: Kauj Ruam 5: Tag Nrho Circuit

Txhua qhov kev tsim hluav taws xob tau tsim los ntawm kev sib txuas plaub lub hauv paus, ntsuas qhov ntsuas qhov ntsuas, ntsuas qhov siab, lim qis dhau, thiab lim siab dhau, hauv koob. Daim duab hluav taws xob puv puv tau qhia hauv thawj daim duab rau theem no.

Cov lus teb simulated tau qhia hauv daim duab thib ob ua raws li nws tau cia siab los ntawm cov khoom ntawm cov khoom siv rau hauv Circuit Court no. Lub Circuit Court uas tau tsim los yog lim tawm suab nrov ntawm ob qho qis thiab sab saud ntawm ECG teeb liab nrog rau ua tiav lim tawm suab nrov los ntawm cov kab hluav taws xob. Lub lim qis dhau ua tiav tshem tawm cov teeb liab hauv qab qhov txiav tawm zaus. Raws li qhia hauv Cov Lus Teb Cov Lus Teb, ntawm 0.01 Hz, lub teeb liab tau dhau los ntawm 1 V, tus nqi uas yog 5 npaug tsawg dua qhov xav tau tso tawm. Raws li qhov nce ntxiv qhov tso tawm hluav taws xob kuj nce ntxiv mus txog thaum nws nce siab ntawm 0.1 Hz. Lub ncov yog nyob ib puag ncig 5 V, uas tau koom ua ke nrog qhov nce ntawm 1000 rau cov cuab yeej siv suab nrov. Lub teeb liab qis dua los ntawm 5 V pib ntawm 10 Hz. Los ntawm lub sijhawm zaus yog 60 Hz, tsis muaj lub teeb liab raug tso tawm los ntawm Circuit Court. Nov yog lub hom phiaj ntawm cov lim dej thais thiab nws lub ntsiab lus los tiv thaiv kev cuam tshuam ntawm cov kab hluav taws xob. Tom qab qhov zaus dhau 60 Hz, qhov hluav taws xob ib zaug ntxiv pib nce nrog zaus. Thaum kawg, ib zaus nce mus txog 110 Hz lub teeb liab nce mus txog qhov siab tshaj ntawm kwv yees li 2 V.

Kauj Ruam 6: Xaus

Lub hom phiaj ntawm txoj haujlwm no yog txhawm rau ntsuas lub tshuab ECG uas muaj peev xwm ntawm kev kaw lub plawv dhia kom raug. Txhawm rau ua qhov no, cov teeb liab sib piv uas yuav tsum tau coj los ntawm tus neeg mob xav tau kom ua kom nrov dua thiab tom qab ntawd lim tsuas yog suav nrog ECG teeb liab. Qhov no tau ua tiav los ntawm thawj zaug siv lub ntsuas qhov ntsuas kom nce qhov loj ntawm lub teeb liab kwv yees li 1000 zaug. Tom qab ntawd lub suab nrov ntawm cov kab hluav taws xob xav tau kom tshem tawm ntawm lub teeb liab nrog rau lub suab nrov saum toj no thiab hauv qab qhov ntsuas ntau zaus ntawm ECG. Qhov no txhais tau tias suav nrog kev lim dej ua haujlwm zoo ib yam li passive siab thiab qis lim lim. Txawm hais tias qhov khoom kawg rau txoj haujlwm no yog simulated Circuit, tseem muaj qee qhov yuam kev siv tau, ua rau kev txiav txim siab tus qauv rau kev tiv thaiv thiab cov khoom muaj peev xwm ib txwm muaj. Tshaj tag nrho cov kab ke ua tau raws li qhov xav tau thiab tuaj yeem hloov pauv mus rau hauv lub cev lub cev yooj yim dua.

Kauj Ruam 7: Cov peev txheej

[1] X. L. Yang, G. Z. Li, Y. H. Tong, H. Yan, Z. Xu, Q. Chen, X. Liu, H.-H. Zhang, H.- IB. Wang, thiab S.-H. Tan, "Keeb kwm, hotspots, thiab kev hloov pauv ntawm electrocardiogram," Journal of geriatric cardiology: JGC, Jul-2015. [Online]. Muaj: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4554… [Nkag mus: 01-Dec-2020].

[2] L. G. Tereshchenko thiab M. E. Josephson, "Cov ntsiab lus nquag thiab cov yam ntxwv ntawm kev siv lub paj hlwb," Phau ntawv Journal of electrocardiology, 2015. [Online]. Muaj: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4624… [Nkag mus: 01-Dec-2020].

[3] "Qhov Sib Txawv Sib Txawv Sib Txawv-Tus Nqis Hluav Taws Xob," Cov Khoom Siv Hluav Taws Xob yooj yim, 17-Mar-2020. [Online]. Muaj: https://www.electronics-tutorials.ws/opamp/opamp_… [Nkag mus: 01-Dec-2020].

[4] C.-H. H. Tsai, S. S. Pan, thiab P. Kinget, “ECG Measurement System,” Columbia University.

[5] S. Akwei-Sekyere, “Kev tshem tawm suab nrov hauv lub zog hauv biomedical teeb tsa ntawm qhov muag tsis pom qhov sib cais thiab kev tshuaj xyuas wavelet,” PeerJ, 02-Jul-2015. [Online]. Muaj: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4493… [Nkag mus: 01-Dec-2020].

[6] "Band Stop Filters hu ua Reject Filters," Basic Electronics Tutorials, 29-Jun-2020. [Online]. Muaj: https://www.electronics-tutorials.ws/filter/band-… [Accessed: 01-Dec-2020].

[7] “Tsawg Dhau Lim-Passive RC Lim Tutorial,” Basic Electronics Tutorials, 01-May-2020. [Online]. Muaj: https://www.electronics-tutorials.ws/filter/filte… [Accessed: 01-Dec-2020].

[8] “Siab Dhau Lim-Passive RC Lim Tutorial,” Basic Electronics Tutorials, 05-Mar-2019. [Online]. Muaj: https://www.electronics-tutorials.ws/filter/filter_3.html [Nkag mus: 01-Dec-2020].