BloodPressure Aliasing

7/25/2019 BloodPressure Aliasing

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DEPARTMENT OF ENGINEERING SCIENCEINSTITUTE OF BIOMEDICAL ENGINEERING

Marco F Pimentel,

Graduate Student,

Centre or Doctoral Trainin! in "ealt#care Inno$ation,

In%titute o Biomedical En!ineerin!,

Uni$er%it& o O'ord

marco()imentel*en!(o'(ac(u

+

Monitorin! Blood Pre%%ure

Biomedical Si!nal Proce%%in!

anuar& -., -/01


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M F Pimentelanuar& -., -/01

Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e -

Outline

S#ort #i%tor&

Deinition o Blood Pre%%ure

3#at i% #&)erten%ion4

5ariou% met#od% u%ed or mea%urement% o 6lood)re%%ure

"o7 oten %#ould 7e mea%ure 6lood )re%%ure4

Sam)lin! and Alia%in!

Ne7 re%ource% 8 An O'ord Uni$er%it& Pro9ect


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e :

T#e ir%t to mea%ure BP

0;:: 2 Re$erend Ste)#en"ale% ir%t to mea%ure BP

Mea%ured t#e #ei!#t o acolumn o 6lood ater

cannulatin! t#e carotidarter& in a #or%e 7it# a6ra%% )i)e(

I


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e >

T#e ir%t mea%urement o BP

T#e 6ra%% )i)e 7a%attac#ed to a 0- inc# !la%%tu6e

Tu6e 7a% connected to t#e

)i)e $ia a trac#ea o a!oo%e


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e .

A %econd tr&?

0// &ear% later@ a mercur& manometer connected to t#earter& 7a% u%ed to mea%ure t#e BP

"o7e$er@

Bot# o t#e%e met#od% are invasive

? And ma&6e? a

6it uncomorta6leor t#e )atient=


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e 1

Eure+a=

In late 0/%, an Italian )#&%ician 8 Sci)ione Ri$a Rocciin$ented t#e S)#&!momanometer

Shygmorom t#e Gree+ )ul%e

Manometer )re%%ure meter

2 Con%i%ted o a mercur& columnManometer, a ru66er %lee$e 7#ic#i% illed 7it# air, and a %ueeHe 6a!to inlate t#e ru66er %lee$e I #ad an

idea=


7/35M F Pimentelanuar& -., -/01

Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e ;

No7ada&% BP monitor%



Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e

3#at i% Blood Pre%%ure4

Blood Pre%%ure i% a mea%urement o t#e orce a!ain%t t#e7all% o t#e arterie% a% t#e #eart )um)% 6lood t#rou!#outt#e 6od&

Blood )re%%ure i% mea%ured in mm"! millimeter% omercur&



Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e


Blood Pre%%ure i% a mea%urement o t#e orce a!ain%t t#e7all% o t#e arterie% a% t#e #eart )um)% 6lood t#rou!#outt#e 6od&

Blood )re%%ure i% mea%ured in mm"! millimeter% omercur&

0,/// Pa i% a6out ; mm"!=



Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e 0/


T#e 6lood )re%%ure readin! i% ta+en in - num6er%@systolic and diastolic(

Systolic

Diastolic

Mea%ure o

)re%%ure a% t#e

#eart i% 6eatin!

Mea%ure o

)re%%ure 7#ile

t#e #eart i% at re%t

6et7een 6eatin!


11/35M F Pimentel

anuar& -., -/01Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!

Pa!e 00

"&)erten%ion

Blood )re%%ure c#an!e% all t#e time@ It decreases7#en 7e %lee), or 7#en 7e are at re%t

It increases7#en 7e are acti$e, e'cited, )racticin! %)ort%,%tre%%ed and ner$ou%

C#an!in!6lood )re%%ure i% a $ital )art o a #ealt#&cardio$a%cular %&%tem

"&)erten%ion, or #i!# 6lood )re%%ure, #a))en% 7#en t#e 6lood)re%%ure stays too high over an extended period of time@

Can cau%e t#e #eart to #a$e to 7or+ too #ard and t#e orce ot#e 6lood lo7 can dama!e &our arterie%, #eart, +idne&%, 6rainand e&e%(


12/35M F Pimentel


Pa!e 0-

"&)erten%ion

Know your numbers:


13/35M F Pimentel


Pa!e 0:

"&)erten%ion

Hypertension depends on several factors:


14/35M F Pimentel


Pa!e 0>

"o7 to mea%ure4

In$a%i$e 6lood )re%%ure IBP@

It mea%ure% t#e BP internall& 6& u%in! a %en%iti$e I5cat#eter in%erted into an %u)ericial arter&( T#i% i% t#e)rocedure ta+en 7#ere continuou% BP monitorin! i%reuired(

Non2in$a%i$e 6lood )re%%ure NIBP@

Au%cultation

O%cillometr&

Do))ler determine% t#e lo7 di%tal to t#e arter&

Arterial tonometr&, Arterial $olume clam) are ot#er t&)e% oNIBP mea%ure


15/35M F Pimentel


Pa!e 0.

"o7 to mea%ure4

Non2in$a%i$e 6lood )re%%ure

Au%cultation

O%cillometr&

Mercur& %)#&!momanometer %tet#o%co)e

Mec#anical manometer %tet#o%co)e


16/35M F Pimentel


Pa!e 01

"o7 to mea%ure4


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e 0;

T#e au%cultation met#od


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S&%tolic BP

Dia%tolic BP


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e -/

T#e o%cillometric met#od


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e -0


It i% 6a%ed on t#ec#an!e o t#ema!nitude oo%cillation

MAP 8 MeanArterial Pre%%ure


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Blood Pre%%ure 2 Biomedical Si!nal Proce%%in!Pa!e --


It i% 6a%ed on t#ec#an!e o t#ema!nitude oo%cillation

MAP 8 MeanArterial Pre%%ure


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"o7 oten %#ould 7e mea%ure4

Let% ir%t con%ider an e'am)le?

MA!A" Demo


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3#& i% t#i% im)ortant or 6lood )re%%ure monitorin!4

"o7 muc# doe% &our 6lood )re%%ure $ar& in one da&4


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3#& i% t#i% im)ortant or 6lood )re%%ure monitorin!4

"o7 muc# doe% &our 6lood )re%%ure $ar& in one da&4

Jot%i% et al( "&)erten%ion, -//.


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Treat

Do not

treat

am

DBP

>am-)m >am

Treatmentt#re%#old

SBP

time

->#r mean

BP

0/)m


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M F Pimentel

#nder$sampling


Pa!e --


Treat

Do not

treat

am>am-)m

0/)m >amtime

%%

%

Treatmentt#re%#old

->#r mean

BP


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M F Pimentel

Aliasing effect


Pa!e --


Treat

Do not

treat

am>am-)m

0/)m >am

BP

time

%%

%

Treatmentt#re%#old


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Under2%am)lin! and alia%in!


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Sam)lin! and Alia%in!

Under2%am)lin! loo%e%im)ortant 7a$e detail%=

It al%o ma& c#an!e t#e 7a$e ormK%#a)edue toAlia%in!

Samplingi% a di%crete o6%er$ation ormea%urement, 7#ile Aliasingi% an

illu%ion, a))earance o %omet#in! t#at i%not, due to %#ortcomin!% o %am)lin!


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Ne7 re%ource%

#tt)@KK777(7orldliee')ectanc&(comKcau%e2o2deat#K#&)erten%ionK6&2countr&


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Lo72co%t BP monitor

#tt)@KKcode(!oo!le(comK)Ke7#26)2)ro9ectK


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Lo72co%t BP monitor

#tt)@KKcode(!oo!le(comK)Ke7#26)2)ro9ectK


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A7ard%


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"rea&'

BloodPressure Aliasing

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