Inconsistent Transmit Frequency

[awdevlin]

Describe the bug We have been collecting RF Data downloaded using the Clarius Cast API. We operate in obstetrics mode. By inspecting the .yml files, we have noticed that the transmit frequency is 2.5 HMz when scanning at a depth of less than 10 cm and 4.0 MHz when scanning at a depth of greater than 10 cm.

1. We have noticed that occasionally (maybe 1/50 scans), the transmit frequency will be 2.5 when we expect 4.0 or vise versa. I don't see a way to determine the frequency until the data is downloaded and processed.

2. One of our team members (with the same setup) claims that they are scanning at 4.0 MHz independent of depth.

3. A bit of a side note, it seems strange than 2.5 MHz is used in the near field and 4.0 MHz is used for the far field. I would have expected the opposite.

To Reproduce We have not been able to reproduce this issue. We have been scanning participants in our study and occasionally the data is captured using a different frequency.

Environment: (We are using an older version to maintain consistency for the duration of our study)

• SDK version: 10.1.1
• Clarius App version: 10.1.1

Let me know if this is something you have encountered before. Any advice would be appreciated.

Best wishes, Alex

[clariusk]

Which probe model are you using while running the Obstetrics application?

[awdevlin]

Everyone on our team is using C3 HD3 probes.

[awdevlin]

We have talked with a few other teams who also can't replicate 4.0 MHz transmit frequency at all depths.

[clariusk]

here is what you should expect in terms of transmit frequency for C3HD3 in Obstetrics

• 3-5cm , 4MHz
• 5-10cm, 3.5MHz
• 10-19cm, 4MHz
• 19-32cm, 3MHz

Of course you can have direct control over this using the low level parameter interface: https://github.com/clariusdev/raw?tab=readme-ov-file#low-level-parameters