Biomedical Engineering Reference
In-Depth Information
24.
Calculate the resistance of a thermistor at 98
F assuming that the resistance of this thermistor
at 12
C is equal to 7.0 k
4,600.
25.
The resistance of a thermistor with a
O
and
b ¼
5,500 measured at 18
C is equal to 250
b ¼
O
. Find the
temperature of the thermistor when the resistance is doubled.
26.
Calculate the
at 21
C (room
b
of a thermistor assuming that it has a resistance of 4.4 k
O
when the room temperature increases by 20 percent.
27.
A Chromel/Constantan thermocouple has the following empirical coefficients:
C
0
¼
temperature) and a resistance of 2.85 k
O
10
2
2.340
10
2
C
1
¼
4.221
10
5
Find the EMF generated by this thermocouple at a temperature of 250
C.
28.
Find the Seebeck coefficient for the Chromel/Alumel thermocouple at a temperature of
200
C.
29.
Explain why the temporal artery thermometer is not used to measure core body temperature
over the radial artery.
30.
Compare and contrast the temporal artery and tympanic thermometers.
31.
Compare and contrast a temperature pill with a temporal artery thermometer.
32.
Sketch the current (
C
2
¼
3.284
y
-axis) versus
p
O
2
(
x
-axis) characteristics of a typical polarographic Clark
electrode.
33.
Explain why the value of the normalized ratio (
) in a pulse oximeter is independent of the
volume of arterial blood entering the tissue during systole.
34.
Explain why the value of the normalized ratio (
R
R
) in a pulse oximeter is independent of skin
pigmentation.
35.
Explain the difference between a potentiometric and amperometric sensor.
36.
Explain the difference between intravascular fiber optic
O
2
and SvO
2
sensors.
37.
A pH electrode is attached to a sensitive voltmeter that reads 0.652 V when the electrode
is immersed in a buffer solution with a pH of 6.7. After the pH electrode is moved to an
unknown buffer solution, the reading of the voltmeter is decreased by 20 percent. Calculate
the pH of the unknown buffer solution.
38.
Plot the optical density, OD, of an absorbing solution (
p
y
-axis) as a function of the concentration
-axis). What is the slope of this curve?
39.
An unknown sample solution whose concentration is 1.55
of this solution (
x
10
3
g/L is placed in a 1 cm clear
holder and found to have a transmittance of 44 percent. The concentration of this sample is
changed such that its transmittance has increased to 57 percent. Calculate the new concentration
of the sample.
40.
Calculate the angle of the refracted light ray if an incident light ray passing from air into
water has a 75-degree angle with respect to the normal.
41.
Explain why fiber optic sensors typically require simultaneous measurements using two
wavelengths of light.
42.
Plot the
fluorescence intensity of a fiber optic
O
2
sensor (
p
y
-axis) as a function of oxygen
concentration (
x
-axis).
Continued
