Session 9 - 3rd July 2016 - Playing with ATL10PV
Previous sessions
- Session 1 : Powering the board, power use, first (bad) trigging and echoes (06 March 2016)
- Session 2 : Non-controlled pulsing, inverters, better echoes (11 March 2016)
- Session 3 : Getting controlled pulsing, but width not controlled (15 March 2016)
- Session 4 : Width of the pulses is getting controlled =) (19 March 2016)
- Session 4b : Simple data visualisation with BitScope (19 March 2016)
- Session 5 : moving the transducer to get the first image (20 March 2016)
- Session 6 : Getting a clinically usable image (28 March 2016)
- Session 7 : Getting cleaner images - code improvements (3 April 2016)
- Session 8 : Comparing acquisition speeds (3 May 2016)
- Session 9 : Playing with ATL10PV (3 July 2016)
Aim of today
Is the ATL 10PV working?
Test of the piezos with echOpen's analog processing chain
Overall echo at 20cm
Zooming in
Zooming in
Details of the echo
Preparing the probe
Some linseed oil was used as a impedance matching material. Works great.. but be sure to overfill the reservoir, since too low oil will result in an oil/air emulsion.. really not usefull to work with.
Setup
Murgen was plugged to the 10PV, its lower piezo aiming downwards (in the axis of the probe). There were some echoes:
These images are lines shot in continuous mode while murgen is aiming at the bottom of a glass.
Is it working when rotating?
Getting data
Having 12V put into the motor, and sorting the matrix of acquisition (1000samples, 5Msps, 1000 pts / lines), shooting at 250us intervals) with a little magic, we see three behaviors. That would fit with 3 piezos. Raw data,bzipped, are available at the archive page.
If cleaning the behavior these 3 behavior, the data becomes
Conclusions
We see echoes on the oscillo, before the enveloppe detection... that's where the signal is. So:
- Murgen is equipped with a enveloppe detection at 3.5MHz, so it's quite normal that it doesn't see the 5, 7.5 and 10MHz.
- The pulser works
- We see clearly 3 behaviors... how come? Since the piezo should be all
- Maybe 12V continuous is too rapid for the motor: I can't see to know where the signal is at what moment. Should be using the second channel of the bitscope to get a saw signal, hence knowing when the lines are shot.
Arty - drawing with ultrasounds
Done with the smart-materials 3.5MHz piezos ad imaging a grape passing in front of a piezo
Light one
Heavy one