medical instrumentation ii. themometer infrared thermometer? medical instrumentation ii t1 = 0 :...

Medical Instrumentation II

Themometer

Infrared thermometer?


T1 = 0 : 0.00001 : 0.0025T2 = 0.0025 : 0.00001 : 0.005T3 = 0.005 : 0.00001 : 0.0075T4 = 0.0075 : 0.00001 : 0.01

Electromagnetic spectrum

1. Audio frequency (20 ~ 20,000Hz)

If 30Hz ?


)(

)()(

frequencyf

htspeedofligcwavelength

kmmHz

ms000,10101

30

103 75

10,000KHz

Electro magnetic spectrum 2. Radio frequency

2-1. Low frequency : 30KHz -> 300KHz

2-2. Medium frequency : 300KHz ->

3MHz 2-3. High frequency : 3MHz -> 30MHz


Wave length10Km -> 1Km

Wave length1Km -> 100m

Wave length100m -> 10m


Antenna

Vc(t)

)1032sin(10)( 7 ttVc

10

-10

X = 0

Vo

smc /103 8

sm

m

/103

108

Electro magnetic system

2-4. Very high frequency : 30MHz ~ 300Mhz (VHF)

2-5. Ultra high frequency : 300MHz ~ 3GHz (UHF)

“ Length of antenna = λ / 2”


Wave length10m -> 1m

Wave length1m -> 0.1m

Micro wave

3-1. Centimeter wave : 3GHz ~ 30GHz

3-2. Millimeter wave : 30GHz ~ 300GHz

3-3. Sub millimeter wave : 300GHz ~ 3Thz


Wave length10Cm -> 1Cm

Wave length10mm -> 1m

Wave length1mm -> 0.1mm

Infrared

4-1. Fan infrared : 10¯⁴ ~ 10⁻⁶ m

4-2. Intermediat infrared : 10μm ~ 1μm


Wave length100μm -> 10

μ m

Visible light

Unit : ~ nm


Longest λ

Shortest λ

Ultra violet

X – ray

R - ray


c

hfrequency

hvE *energy

Plank constant

Infrared (detail)

All material generate electric wave. It’s wavelength is in inverse

propotion to temperature.


T

1


Red is long wavelengthBlue is short wavelength

Visible rays Bandwidth

Λ2 ~ 10nm

We can not visible in no light

Λ2 ~ 10μm

mTm 2898


Absolute temperat

ure

EX) Human have 25 0C temperature. -> T is about 300K.

4TWt

Maximumenergy

Energy

Ex) CIC thermometer

Radiation thermometer


R -> V

ADC MP LCD

Battery

IR Op-amp

circuit

ADC MPLCD

Switchinfrared

Shutter

Lens

IR sensor (pyroelectric sensor)

Pyroelectric sensor


Infrared Input

Infrared Output

<Summery>Resistive, Capacitive, Inductive Sensor

and Piezoelectric, EM spectrum, Radiation thermometer, Phase-

sensitive demodulation

medical instrumentation ii. themometer infrared thermometer? medical instrumentation ii t1 = 0 :...

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