7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 1/21

 

Design of Health TechnologiesDesign of Health Technologies

lecture 12lecture 12

 John Canny John Canny

10/17/0510/17/05

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 2/21

 

Advanced Sensing SystesAdvanced Sensing Systes

Biosensors:

!lucose onitoring

"ther systes

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 3/21

 

#agneto$elastic sensors#agneto$elastic sensors

%!ries&%!ries& The agneto$elastic aterial resonates at a

characteristic fre'uency (hen e)cited *y aagnetic +eld,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 4/21

 

#agneto$elastic sensors#agneto$elastic sensors

 The agneto$elastic ri**on is ade of acoercial sheet called #etglas,

 The -olyer is a custo co$-olyer ade *y the

!ries grou-, .t is *elieved to (or *ecauseglucose *onds to sites on -olyer chains thatse-arate the fro other chains, This allo(s the-olyer to a*sor* (ater,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 5/21

 

#agneto$elastic sensors#agneto$elastic sensors

.ts fre'uency res-onse %in air& sho(s a shar- -ea(hich is deterined *y the density of the-olyer layer

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 6/21

 

#agneto$elastic sensors#agneto$elastic sensors

esonant fre'uency in a li'uid is lo(er and the-ea is not as shar-,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 7/21 

#agneto$elastic sensors#agneto$elastic sensors

re'uency res-onse in (ater varies (ith the glucoseconcentration in an alost -erfectly linearcurve,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 8/21 

Sensor easureentSensor easureent

 The electronics are si-le, A shar- s-ie is a--liedto a driving coil and a res-onse is easured in asense coil,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 9/21 

Sensor easureentSensor easureent

 The agnetic s-ie is short a*out 3 gauss for 14icro$seconds %earths agnetic +eld is a*out 0,5gauss and a refrigerator agnet a*out 10 gauss&,

 The -icu- coil easures sensor activity for a further6 illi$seconds, The res-onse is transfored (ithan T to deterine the fre'uency -ea,

 This should *e easy to do (ith a sall *attery$-o(ered device, ecause the sensors res-onse is'uite slo( %tens of inutes to res-ond& it isenough to tae readings every fe( inutes,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 10/21 

iosensor statusiosensor status

 There are any -roising systes on the hori8on*ut the only coercially$de-loyed *iosensorsare glucose onitors %9:;&, 3 ain ty-es<

Single Use: Dis-osa*le sensing aterial often=static> easureent, Chea- and -orta*le *utlo( sensitivity and accuracy,

Intermittent Use: "ften use hydrodynaics ?generally uch *etter -erforance fro sensinga oving @uid, .ts still a challenge to ove theseout of the la* and onto a chi-,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 11/21 

iosensor statusiosensor status

Continuous (In Vivo) Sensors: ery econoical*ut very hard to cali*rate and ay suBer frounno(n aount of drift,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 12/21 

iosensor designiosensor designe give a *rief introduction to icro$@uidic sensor

design,

hile these (ere originally fa*ricated in silicon using##S techni'ues the trend is to(ard glass and

-lastic as the su*strate,

oth glass and any -lastics allo( o-ticaleasureents *ut silicon is o-a'ue to visi*le light,

!lass and -lastic are also ore resistant tocontaination fro the cheicals used in theeasureent,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 13/21 

iosensor designiosensor design

Surface immobilization: The +rst ste- is sensingis creating a selective surface to react to thesensed agent

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 14/21 

iosensor designiosensor design

Bead immobilization: A variation that uses *eadsto increase relative surface area,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 15/21 

iosensor designiosensor design

Detection: Several ethods including resonantfre'uency of ##S cantilevers, ut a-eroetry%current easureent& is the ost (idely useda--roach, Ty-ical echaniss for current @o(include redo) cycles *et(een the target grou-

and variants,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 16/21 

iosensor designiosensor design

Optical Detection: A 2Darray of agent/antigenreactions -roduces@uorescent traces<

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 17/21 

iosensor designiosensor design

agnetic Detection: The anti*odies areio*ili8ed on a surface and agnetic *eads*ind to sites (here the analyte is attached,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 18/21 

!n8ye$"ined Iunosor*ent#ssay

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 19/21 

$euse

#ost iunosensors use *ound anti*odies and#ost iunosensors use *ound anti*odies and

io*ili8ation, eoving the *ound s-ecies can *eio*ili8ation, eoving the *ound s-ecies can *e

diEcult (ithout destroying the sensors,diEcult (ithout destroying the sensors,

#ethods and results vary *ut a recent detector for#ethods and results vary *ut a recent detector forChagas disease used glycine$HCl to (ash theChagas disease used glycine$HCl to (ash the

sensor and re-orted eEcacy for ore than 30sensor and re-orted eEcacy for ore than 30

cycles,cycles,

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 20/21 

iosensor designiosensor designS%stems&on&a&c'ip: are -roising *ut coing

slo(ly, iosensing still sees a long (ay frocoercial via*ility, ut there are soe-roising -rototy-es<

7/23/2019 Design of Health Technology

http://slidepdf.com/reader/full/design-of-health-technology 21/21

Discussion FuestionsDiscussion Fuestions

1,1, .t ay *e a (hile *efore (e have highly.t ay *e a (hile *efore (e have highly

integrated sensors for any -athogens %andintegrated sensors for any -athogens %and

econoics dictates that they (ill coe for +rst$econoics dictates that they (ill coe for +rst$

(orld diseases +rst&, Can you thin of(orld diseases +rst&, Can you thin of

teleedicine/inforation tools to hel- facilitateteleedicine/inforation tools to hel- facilitatetraditionaltraditional %*ut si-le& la* ethodsG%*ut si-le& la* ethodsG

2,2, Sensors for edical diagnosis ay al(ays *e aSensors for edical diagnosis ay al(ays *e a

diEcult econoic -ro-osition, Can you thin ofdiEcult econoic -ro-osition, Can you thin ofother odels that ight (orG ,g, hoeother odels that ight (orG ,g, hoe

testingGtestingG