Ultrasound phantom audio data
The data was obtained from the phantom type DFS 384 shown below. It was made by Danish Phantom Design.
The phantom generates a constant flow in a 13.6 mm diameter tube. The tube has a wall thickness of 0.2 mm, and the attenuation of the surrounding medium is 0.5 dB/[MHz cm]. The audio signal from the scanner was sampled for a number ofseconds. You can find more information about the laboratory at the CFU home page.
The data for the measurements are given below:
| Ultrasound scanner: | B-K Medical A/S type 3535 |
| Scan mode: | Duplex |
| Transducer: | B-K 8556, 3.2 MHz linear array probe |
| Transducer center frequency: | 3.2 MHz |
| B-mode frame rate: | 27 f/s |
| B-mode gain: | 30% |
| Doppler gain: | 73% |
| Pulse repetition frequency: | 3.5 kHz |
| Wall filter: | cut-off at 0.3 cm/s |
| Angle between flow and beam: | 35° |
| Sampling frequency: | 8 kHz |
| Resolution: | 16 bits samples |
The data can be obtained from the ftp-server from the directory:
Several files are found. The properties are listed in the following table:
| File name | Duration | Place of sampling | Depth | Range gate |
|---|---|---|---|---|
| pht_center1.wav | 10.34 s | Center of vessel | 47 mm | 2 mm |
| pht_center2.wav | 10.78 s | Center of vessel | 47 mm | 4 mm |
| pht_edg1.wav | 10.34 s | Edge of vessel | 55 mm | 2 mm |
| pht_edg2.wav | 10.45 s | Edge of vessel | 55 mm | 4 mm |
Depth is the distance from the transducer surface to the center of the range gate used during the measurement.
Both the raw audio data as wave files (extension .wav) can be found, along with the complex audio data in a Matlab file (extension .mat). The last file can be directly read and manipulate with Matlab. The variable complex_data contains the complex data, forward is the forward flow signal, and reverse is the reverse flow signal. The wave file can be read by the command wavread in Matlab 5.1. Note that this does not work in Matlab 5.0, due to a bug in wavread.
Note:
The audio data was not sampled simultaneously with the RF data given on the other web-page, and the velocities, angles, and depths are different as well.