Biomedical Engineering Reference
In-Depth Information
fully agreement with the ultrasonic pulse-echo measurements used to estimate the sound
velocities in the different liquids, which are reported in Table 1.
5
Sample 2
=96
mPa.s
Sample 3
=990
mPa.s
Sample 4
=4900
mPa.s
4
3
2
1
0
0
1000
2000
3000
4000
5000
Frequency (Hz)
Fig. 2. Effect of viscosity on the magnitude of acoustical impedances measured in a setup as
illustrated in Figure 1 at the driver position x = 0. Liquids 2, 3 and 4 were tested and
properties and given in Table 1.
10000
1000
100
10
Measurement Liquid 1
Measurement Liquid 2
Measurement Liquid 3
Measurement Liquid 4
Reference Viscosity
1
0
1000
2000
3000
4000
5000
Frequency (Hz)
Fig. 3. Viscosities obtained from the different resonance frequencies for 4 different liquids
obtained from the measured mechanical impedance and from Equation (7).
