• Retroengineering an ultrasound probe - part 1/X

    kelu1242 days ago 0 comments

    I just got an interesting mechanical probe, a Bard Site Rite - piezo at 7.5MHz. The plug is quite simple, and digging into the cable yields 2 pairs of cable, one coax, a bigger cable with two "big" cables. I've made sure it's a mechanical probe. The aim is to try and see if I can connect it to my board and get an image.

    Good point for this probe is that it unscrews nicely.

    and even better, it has changeable heads!

    I assume two pairs of cables are for motors / actuators, coax is for the signal coming back (hence the bead). But how can I see that on the pins above?

    Going to search for the reference manual and other resources. I'd rather not unscrew the head yet!

    To be continued... possibly with a corresponding patent... Electromagnets?

  • Progressing with the signal acquisitions

    kelu12402/27/2018 at 22:07 0 comments

    Some good news again =)

    I got to better control pulses (I need to really read more carefully  datasheets), got acquisitions at 64Msps, really looking good, and got some (badly formed at the moment) images!

    Acquisitions - going to specs at 64Msps. Thanks David =)

    Pulser: getting 200ns wide 75V pulses (blue is the pulse with a piezo on, in yellow is the 'damping' control signal.

    Getting some images from a "damaged" probe

    More on the log!

  • Getting great results

    kelu12402/24/2018 at 19:43 3 comments

    That's moving forward! I'm getting some results with the following setup - using a piezo with a fixed distance, and a pulser at 25V.

    Getting nice echoes (x-label in us)

    The gain control works as well =)

    and the FFT looks relatively clean!

  • More hacks

    kelu12402/11/2018 at 22:47 0 comments

    I needed to replace some elements, some stuff is erratic, but hey, I've been able to set up all registers, run the analog part, and control the DAC gain.  I (just) need to run the ADC now, the fpga still thinks s.he's not working ;)

    Some pulse control works, and pulses too! With a 10x probe, on a 25V pulse

    Next step.. digitalization. More on the log.

  • Further tests

    kelu12401/26/2018 at 20:23 0 comments

    The clock had to be removed!

    Investigation showed no connection through USB.. a ftdi issue. Powers were OK.. but still nothing.

    So what? Clock!!

    I unfortunately destroyed the 12MHz clock.. well that's it =) I'll be waiting for the new one from digikey.

    The clock has to be rotated by 90°

    More on the next session !

  • Let's have a first peek

    kelu12401/26/2018 at 20:16 2 comments

    This has reached a couple of days ago =)

    Looks good - ice40 and ram look good. The high-level pulser footprint seems reversed. The 3.3V is on, 5V level looks good, seems good!