ZMT zurich med tech

Hello,

Sorry I am facing an issue with moving antennas to different locations based on the steps above. I used three points on the skin and calculated the transformation between static and posed states. I used this transformation to transform the antenna position to the new position (using RigidTransform and ApplyTransform functions).

However I get errors that the antenna source edge is within a solid. I have changed priorities during voxelling providing antennas higher priority but the errors still exist. What can I do? I would like to move antennas in a similar fashion to how soft tissues deform.

Thanks
Vignesh

Hi,

Thank you. I tried it but would like to plot the fields on a grid between antennas (as shown in red in the image). It is easy when the model is static but when posed, I am not able to get a grid at an angle.

Thanks

image.png

That's great to hear! Thank you so much for sharing your experience. I'll explore the option of implementing something similar for EM simulation.

Hi Bryn,

I would like to ask a question regarding posing. My aim is to detect the variation in bone position from the skin in different poses (hypothesis being: as the soft tissues deform, the bone wont always be at the same position wrt the skin). I currently have 8 antennas placed around the skin which are supposed to mimic wearable antennas and I would like to move these antennas along with the pose.

But if I link these antennas to the bone using "link-parent tool", the bone is always at the same location wrt to the bone irrespective of the pose. But I cannot link the antennas wrt to the skin as the antennas dont move with the pose.

How can I do this? I would like the antennas which are placed around the skin to similar to the skin rather than the bone? Based on the first video in this chain, triangular meshes can be posed similar to the body. If I convert the antennas to meshes and then pose it, will I be getting the same issue i.e the bone is always at the same location wrt to the antennas?

Thanks

A simulation can end in a couple different cases: If the specified level of convergence is reached, or if the specified number of periods are simulated. In the case of that tutorial, the simulation is set to run for 15 periods, and so it ended before a -50 dB convergence was reached. Convergence is a spectrum, and the level of convergence required for a given application is up to the user's discretion.

@bryn Thank you Bryn.
Managed to find a version that wasn't corrupted!
Hope you have a nice day 🙂

@halder Thank you for your response. I want the total current of 1 mA flowing between my two electrodes. In this case, I should put the target value as (1 mA/area of the plane I have drawn between two electrodes)?
since my plane area is 182mm*220mm, then I should select the target value to be 0.024975 A/m2. Is this the correct approach?

Thanks Ofi. How can I fix this or is this something I need to account for?

Hi @arc Please check "Console" window (open it via menu VIEW | Console if it is not open) to see what kind of error you are getting. The reason for failed simulation might be related to something else. You can easily test with an existing tutorial example. For example,

open Dipole Antenna Tutorial, model a rectangular brick next to the dipole, clone one of the existing simulation settings and drag&drop this new brick into the simulation set its material such that rel/ Permeability o 1e4 generate grid, voxel and run to see if it also fails
I hope it helps.

Yes,

You need to import XMaterials and specify the material model to be linear dispersive, as in the following example (which should be easy to extend), where parameters for one Debye pole are assigned.

import XMaterials as xm # Adding a new MaterialSettings material_settings = emfdtd.MaterialSettings() material_settings.ElectricProps.MaterialModel = material_settings.ElectricProps.MaterialModel.enum.LinearDispersive # Specify settings for dispersive poles material_settings.raw.ElectricDispersiveSettings.StartFrequency = 10.e6 material_settings.raw.ElectricDispersiveSettings.EndFrequency = 100000.e6 material_settings.raw.ElectricDispersiveSettings.Conductivity = 0. material_settings.raw.ElectricDispersiveSettings.Permittivity = 11.098 debye_pole_01 = xm.LinearDispersionPole() debye_pole_01.Active = True debye_pole_01.Type = xm.LinearDispersionPole.ePoleType.kDebye debye_pole_01[xm.LinearDispersionPole.ePoleProperty.kDebyeAmplitude] = 1.0 debye_pole_01[xm.LinearDispersionPole.ePoleProperty.kDebyeStaticPermittivity] = 22.67 debye_pole_01[xm.LinearDispersionPole.ePoleProperty.kDebyeInfinityPermittivity] = 11.098 debye_pole_01[xm.LinearDispersionPole.ePoleProperty.kDebyeDamping] = 3.234e-11 # Add dispersive poles to the Linear Electric Dispersion Viewer material_settings.raw.ElectricDispersiveSettings.Poles = [debye_pole_01]

Then you can keep the substrate as it is and translate the edge source (polyline) along the microstrip line until it also touches the ground plane (keeping it always axis-aligned).

I suspect that this is because the grid from your LF simulation does not match the grid that you use in your isotropic and anisotropic simulations.

The isotropic simulation runs fine because it does not use your cache file.

The anisotropic simulation has stored those conductivity values expecting a specific grid.

Try right clicking on the grid settings folder in the simulation from which you are creating your anisotropy tensor, select "Copy Grid Configuration", then "Paste Grid Configuration" on the anisotropic simulation.

If you want to include features in your anisotropic simulation that you don't don't want to have simulated in your initial LF simulation, you can still include include objects in your initial simulation so that they are considered for the gridding without assigning them material properties, using them as a boundary condition or voxeling them. Just drag the object directly into the grid settings folder. That way your grid can always match.

The following example for a 2-port simulation combiner should help.

i = 0 for channel in em_multi_port_simulation_combiner.GetChannelWeights(): power = [1.0, 2.0] phase = [45, 90] em_multi_port_simulation_combiner.SetChannelWeight(channel, power[i], phase[i]) i += 1 em_multi_port_simulation_combiner.UpdateAttributes() em_multi_port_simulation_combiner.Update() document.AllAlgorithms.Add(em_multi_port_simulation_combiner)