AMMR4 beta - Abdominal pressure

Hello AnyBody Team,

I've recently started using the new Abdominal Model from AMMR4-beta and I'm interested in working with the abdominal pressure values. In the previous AMMR version, I used to find these values in Output/BodyModel/Trunk/Buckle/AbdominalPressureMuscle1/Fout.

However, in exploring the new version, I've noticed that there are pressure values for the four different layers, upper cavity, and lower cavity of the new abdominal model, but I couldn't find an integral value for abdominal pressure as before. Am I missing something here?

Is there comparable metric in the new AMMR for overall abdominal pressure? Alternatively, is there a method to calculate abdominal pressure using the values provided for the individual layers and cavities?

I appreciate any insights or suggestions you can provide. Thank you in advance for your help!

Best regards,
Mareike

Dear Mareike,

First of all, in the new abdominal model, we do not have buckle segment anymore and instead we have the layers. There are 6 volumes and you can check the pressure values in the PressureActuators folder shown in the following picture:

The pressure on the volumes grow downward because they are masses on the layer segments, and that is the only difference between the pressures in different layers :slight_smile: The masses represent whatever is inside the abdomen. So if we remove the masses from the layers, the pressure values will be the same for all volumes, which make sense because they are connected together.

So if you are interested in the pressure closer to pelvis, take the LowerCavity pressure, or if you are interested in the pressure just below the diaphragm, take the UpperCavity pressure. Or you can have an average of them. That is your decision :slight_smile:

2 Likes

Dear Hamed,

Thank you for your help.

I have another question:

In an older file (AMMR2.4.4), I found this note describing the unit of the abdominal pressure:

I have noticed that the values for Fout for the LowerCavity are about a factor of 10 larger in the new AMMR. In the code, I only found this:

image

What is the unit for the abdominal pressure in AMMR4?

Best regards,
Mareike

Dear Mareike,

The mechanism of the previous abdominal model and the new one are very different. In the new one we have the volumes (as a newly implemented measures) that can have pressure inside. And the pressure value units are pascal (Pa) :slight_smile:

The strength that you see here is not important anymore, and we just made a big one, so it can create big pressures as much as it needs. The benefit is that the limiting factor is not the pressure actuators inside the volumes, which means that the pressure will be limited by the abdominal muscle configurations and strength.

Best regards,
Hamed