I-Fingertip pulse oximeter yasungulwa yiMillikan ngawo-1940 ukuze iqaphe ukugcwala komoya-mpilo egazini lemithambo yegazi, okuyisibonakaliso esibalulekile sobukhali be-COVID-19.Yonker manje ichaza ukuthi i-oximeter ye-pulse yeminwe isebenza kanjani?
Izici zokumuncwa kwe-spectral kwezicubu zebhayoloji: Uma ukukhanya kukhanyiswa ezicutshini zebhayoloji, umphumela wezicubu zebhayoloji ekukhanyeni ungahlukaniswa ngezigaba ezine, okuhlanganisa ukumuncwa, ukuhlakazeka, ukubonakaliswa kanye nokukhanya. Uma ukuhlakazeka kungafakwanga, ibanga elihamba ukukhanya ezicutshini zebhayoloji lilawulwa kakhulu ukumuncwa. Lapho ukukhanya kungena kwezinye izinto ezisobala (eziqinile, eziwuketshezi noma eziwugesi), ukuqina kokukhanya kwehla kakhulu ngenxa yokumuncwa okuqondiwe kwezinye izingxenye ezithile zemvamisa, okuyisenzakalo sokumuncwa kokukhanya yizinto. Ukuthi into imunca ukukhanya okungakanani kubizwa ngokuthi ukuminyana kwayo okubonakalayo, okwaziwa nangokuthi ukumuncwa.
Umdwebo weskimu wokumuncwa kokukhanya ngezinto kuyo yonke inqubo yokusabalala kokukhanya, inani lamandla okukhanya amuncwa yizinto lilingana nezici ezintathu, okungukuthi ukuqina kokukhanya, ibanga lendlela yokukhanya kanye nenani lezinhlayiya ezimunca ukukhanya engxenyeni ephambene yendlela yokukhanya. Ngokwesisekelo sezinto ezilinganayo, inombolo yendlela yokukhanya izinhlayiya ezimunca ukukhanya engxenyeni ephambene zingabhekwa njengezinhlayiya ezimunca ukukhanya ngevolumu yeyunithi, okungukuthi ukugxila kwezinhlayiya zokukhanya kwezinto, kungathola umthetho we-lambert beer: kungahunyushwa njengokugxiliswa kwezinto kanye nobude bendlela yokukhanya ngevolumu yeyunithi ngayinye yobuningi be-optical, ikhono lokukhanya kokumunca izinto ukuphendula emvelweni wokukhanya kokumunca izinto. Ngamanye amazwi, ukuma kwejika le-spectrum yokumunca lento efanayo kuyafana, futhi isikhundla esiphelele se-peak yokumunca sizoshintsha kuphela ngenxa yokugxila okuhlukile, kodwa isikhundla esihlobene sizohlala singashintshi. Enqubweni yokumunca, ukumuncwa kwezinto zonke kwenzeka kuvolumu yesigaba esifanayo, futhi izinto ezimunca azihlobene, futhi azikho izinhlanganisela ze-fluorescent ezikhona, futhi akukho mkhuba wokushintsha izakhiwo ze-medium ngenxa yemisebe yokukhanya. Ngakho-ke, ngesisombululo esinezingxenye zokumunca ze-N, ubuningi be-optical buyisengezo. Ukwengezwa kobuningi be-optical kunikeza isisekelo sethiyori sokulinganisa inani lezingxenye ezimuncayo ezixutshweni.
Ku-biological tissue optics, isifunda se-spectral esingu-600 ~ 1300nm sivame ukubizwa ngokuthi "ifasitela le-biological spectroscopy", futhi ukukhanya okukuleli bhendi kunencazelo ekhethekile yokwelashwa okuningi kwe-spectral okwaziwayo nokungaziwa kanye nokuxilongwa kwe-spectral. Esifundeni se-infrared, amanzi aba yinto eyinhloko emunca ukukhanya ezicutshini ze-biological, ngakho-ke ubude be-wavelength obusetshenziswa uhlelo kumele bugweme ukuphakama kokumunca kwamanzi ukuze kutholakale kangcono ulwazi lokumunca ukukhanya kwento eqondiwe. Ngakho-ke, ngaphakathi kobubanzi be-spectrum ye-infrared obungu-600-950nm, izingxenye eziyinhloko zezicubu zomunwe womuntu ezinomthamo wokumunca ukukhanya zifaka amanzi egazini, i-O2Hb (i-hemoglobin ene-oxygen), i-RHb (i-hemoglobin encishisiwe) kanye ne-peripheral skin melanin nezinye izicubu.
Ngakho-ke, singathola ulwazi olusebenzayo lokuhlushwa kwengxenye okufanele ilinganiswe esicutshini ngokuhlaziya idatha ye-emission spectrum. Ngakho-ke uma sinohlu lwamazinga e-O2Hb kanye ne-RHb, siyazi ukugcwala komoya-mpilo.Ukugcwala kwe-oxygen SpO2Ingabe iphesenti levolumu ye-hemoglobin eboshelwe umoya-mpilo (HbO2) egazini njengephesenti le-hemoglobin ephelele ebophayo (Hb), ukuhlushwa kwe-oxygen pulse yegazi ngakho kungani ibizwa ngokuthi i-pulse oximeter? Nasi umqondo omusha: ivolumu yokugeleza kwegazi igagasi lokushaya kwenhliziyo. Phakathi nomjikelezo ngamunye wenhliziyo, ukufinyela kwenhliziyo kubangela ukuthi umfutho wegazi ukhuphuke emithanjeni yegazi yempande ye-aortic, ekhulisa udonga lwemithambo yegazi. Ngokuphambene nalokho, i-diastole yenhliziyo ibangela ukuthi umfutho wegazi wehle emithanjeni yegazi yempande ye-aortic, okubangela ukuthi udonga lwemithambo yegazi lufinyele. Ngokuphindaphindwa okuqhubekayo komjikelezo wenhliziyo, ushintsho oluqhubekayo lwengcindezi yegazi emithanjeni yegazi yempande ye-aortic luzodluliselwa emithanjeni engezansi exhunywe nayo ngisho nakulo lonke uhlelo lwemithambo yegazi, ngaleyo ndlela kwakhiwe ukwanda okuqhubekayo nokufinyela kodonga lonke lwemithambo yegazi. Okusho ukuthi, ukushaya kwenhliziyo ngezikhathi ezithile kudala amaza okushaya kwenhliziyo ku-aorta ageleza phambili ezindongeni zemithambo yegazi kulo lonke uhlelo lwemithambo yegazi. Isikhathi ngasinye lapho inhliziyo ikhula futhi ifinyela, ushintsho ekucindezelweni ohlelweni lwemithambo yegazi lukhiqiza igagasi lokushaya kwenhliziyo ngezikhathi ezithile. Yilokhu esikubiza ngokuthi i-pulse wave. I-pulse wave ingabonisa ulwazi oluningi oluphathelene ne-physiological njengenhliziyo, umfutho wegazi kanye nokugeleza kwegazi, okungahlinzeka ngolwazi olubalulekile lokuthola imingcele ethile yomzimba womuntu ngendlela engahlaseli.
Kwezokwelapha, i-pulse wave ivame ukuhlukaniswa nge-pressure pulse wave kanye ne-volume pulse wave izinhlobo ezimbili. I-pressure pulse wave imelela kakhulu ukudluliswa kwengcindezi yegazi, kanti i-volume pulse wave imelela izinguquko eziqhubekayo ekugelezeni kwegazi. Uma kuqhathaniswa ne-pressure pulse wave, i-volumetric pulse wave iqukethe ulwazi olubaluleke kakhulu lwenhliziyo nemithambo yegazi yabantu kanye nokugeleza kwegazi. Ukutholwa okungahlaseli kwe-blood flow volume wave evamile kungatholakala ngokulandelela i-photoelectric volumetric pulse wave. I-wave ethile yokukhanya isetshenziselwa ukukhanyisa ingxenye yokulinganisa yomzimba, futhi i-beam ifinyelela ku-photoelectric sensor ngemuva kokubonakaliswa noma ukudluliselwa. I-beam eyamukelwe izophatha ulwazi olusebenzayo lwe-volumetric pulse wave. Ngenxa yokuthi i-volume yegazi iyashintsha njalo ngokukhula nokufinyela kwenhliziyo, lapho inhliziyo i-diastole, i-blood volume iyona encane kunazo zonke, ukumuncwa kwegazi kokukhanya, i-sensor ithole ukuqina kokukhanya okuphezulu; Lapho inhliziyo ifinyela, i-volume iphakeme futhi ukuqina kokukhanya okutholwe yi-sensor kuncane kakhulu. Ekutholweni okungahlaseli kweminwe nge-blood flow volume wave pulse wave njengedatha yokulinganisa eqondile, ukukhethwa kwendawo yokulinganisa ye-spectral kufanele kulandele izimiso ezilandelayo
1. Imithambo yegazi kufanele ibe miningi kakhulu, futhi isilinganiso solwazi olusebenzayo njenge-hemoglobin kanye ne-ICG kulwazi oluphelele lwezinto ezibonakalayo ku-spectrum kufanele sithuthukiswe.
2. Inezici ezisobala zokushintsha kwevolumu yokugeleza kwegazi ukuze iqoqe ngempumelelo isignali yegagasi lokushaya kwenhliziyo
3. Ukuze kutholakale ububanzi bomuntu obuphindaphindekayo nokuqina okuhle, izici zezicubu azithinteki kakhulu ngomehluko womuntu ngamunye.
4. Kulula ukwenza ukutholwa kwe-spectral, futhi kulula ukwamukelwa yilowo othintekayo, ukuze kugwenywe izinto eziphazamisayo njengokushaya kwenhliziyo okusheshayo kanye nokunyakaza kwesimo sokulinganisa okubangelwa imizwa yokucindezeleka.
Umdwebo wesimiso wokusatshalaliswa kwemithambo yegazi entendeni yesandla somuntu Indawo yengalo ayikwazi ukubona igagasi le-pulse, ngakho-ke ayifaneleki ukuthola igagasi le-pulse volume flow flow; Ingalo iseduze nomthambo we-radial, isignali ye-pressure pulse wave inamandla, isikhumba kulula ukukhiqiza ukudlidliza komshini, kungaholela esignalini yokuthola ngaphezu kwegagasi le-pulse volume futhi liphethe ulwazi lwe-pulse reflection yesikhumba, kunzima ukuchaza ngokunembile izici zokushintsha kwevolumu yegazi, akufaneleki endaweni yokulinganisa; Nakuba intende ingenye yezindawo ezivamile zokudweba igazi emitholampilo, ithambo layo likhulu kunomunwe, futhi ubukhulu begagasi le-pulse volume yesundu eliqoqwe ngokubonakaliswa okusabalele buphansi. Umfanekiso 2-5 ukhombisa ukusatshalaliswa kwemithambo yegazi entendeni yesandla. Uma ubheka lesi sibalo, kungabonakala ukuthi kunenethiwekhi eziningi ze-capillary engxenyeni engaphambili yomunwe, ezingabonisa ngempumelelo okuqukethwe kwe-hemoglobin emzimbeni womuntu. Ngaphezu kwalokho, lesi sikhundla sinezici ezisobala zokushintsha kwevolumu yokugeleza kwegazi, futhi siyindawo efanele yokulinganisa igagasi le-pulse volume. Izicubu zemisipha namathambo zeminwe zincane kakhulu, ngakho-ke ithonya lolwazi lokuphazamiseka kwangemuva lincane kakhulu. Ngaphezu kwalokho, isihloko somunwe kulula ukusilinganisa, futhi umuntu akanawo umthwalo wengqondo, okwenza kube lula ukuthola isignali ye-spectral ezinzile yesilinganiso sesignali kuya komsindo. Umunwe womuntu uqukethe amathambo, izinzipho, isikhumba, izicubu, igazi lemithambo yegazi kanye negazi lemithambo yegazi. Enkambisweni yokusebenzisana nokukhanya, umthamo wegazi emthanjeni ongaphandle komunwe uyashintsha ngokushaya kwenhliziyo, okuholela ekushintsheni kokulinganisa indlela yokukhanya. Ngenkathi ezinye izingxenye zihlala njalo kuyo yonke inqubo yokukhanya.
Uma kusetshenziswa ubude obuthile bokukhanya ku-epidermis yesihloko somunwe, umunwe ungabhekwa njengengxube, okuhlanganisa izingxenye ezimbili: into engaguquki (indlela yokukhanya ihlala njalo) kanye ne-dynamic matter (indlela yokukhanya iyashintsha ngobuningi bezinto). Lapho ukukhanya kumuncwa yizicubu zesihloko somunwe, ukukhanya okudlulisiwe kwamukelwa yi-photodetector. Ubukhulu bokukhanya okudlulisiwe okuqoqwe yi-sensor buyancipha ngokusobala ngenxa yokumuncwa kwezingxenye ezahlukahlukene zezicubu zeminwe yomuntu. Ngokusho kwalesi sici, imodeli efanayo yokumuncwa kokukhanya kweminwe iyasungulwa.
Umuntu ofanelekayo:
I-oximeter yokushaya kwenhliziyo yeminweifanele abantu babo bonke ubudala, okuhlanganisa izingane, abantu abadala, asebekhulile, iziguli ezinesifo senhliziyo, umfutho wegazi ophakeme, i-hyperlipidemia, i-cerebral thrombosis nezinye izifo zemithambo yegazi kanye neziguli ezine-asthma, i-bronchitis, i-bronchitis engapheli, isifo senhliziyo samaphaphu kanye nezinye izifo zokuphefumula.
Isikhathi sokuthunyelwe: Juni-17-2022
