IMU #9
Description
Shamelessly copied from a new intern's (Kelly M) support request:
In my new intern's Clarius Cloud, please note the following exams:
2 images, 1 cine (3 seconds) taken during an exam that lasted less than 10 seconds:
T14_INTEST: red path, acquisition time ~ 7-8 sec
T15_INT EST: blue path, acquisition time ~ 7-8 sec
T16_INTEST: green path, acquisition time ~ 7-8 sec
1 cine (3 second) taken during an exam that lasted less than 5 seconds:
T17_INTEST: red path, acquisition time ~ 4-5 sec
T18_INTEST: blue path, acquisition time ~ 4-5 sec
T19_INTEST: green path, acquisition time ~ 4-5 sec
Prior to all exams, a stationary calibration of the PA HD3 scanner was completed. During the scan, the IMU and RAW data icons were selected to collect the data throughout the ultrasound exam. During the exam, the scans were completed with the Clarius probe oriented at shown in Figure 1. Figure 1 also shows the orientation of the scanner and the paths the scanner followed during each exam. I used the axis orientations give on Clarius's GitHub.
Q1. Are the axes correctly labeled in my image in correspondence to the IMU data?
During T14 and T17, I scanned for about 5 seconds while moving the scanner along the red path from point 1 to 2 in the -z direction. For T15 and T18, I moved the scanner along the blue path in the -y direction. For T16 and T19, I moved my scanner along the black path in the +x direction.
I have attached the associated IMU files for reference. Please let me know if you need additional files. From the IMU file, I plotted the data of the gyroscope and accelerometer versus time for each exam listed. I have attached these figures and the Matlab script (ClariusMotionIMU.m) that I used to create them. The data in the figures is quite noisy and does not reflect what I would expect from the results. I have a few questions because of this:
Q2. What would the correct unit be for the y-axis of the Gyroscope vs Time and Accelerometer vs Time be?
Q3. Could the horizontal time axis be scaled incorrectly? Dividing timestamps by 1e9 doesn't always generate a time range corresponding to my acquisition time.
Q4. Is there a reason that you believe the data I am collecting is not clearly representing the motion of the scanner during the exams? For instance, in the T14 exam, I would expect the yellow "gz" line to fluctuate much more than the gx and gy lines, however there is no obvious difference.
Q5. Do we need to pull IMU data from Clarius Cast rather than the Clarius Cloud?
Thank you for the help!
Best,
Sarah P and
Kelly.M