Returning Pneumothorax to Initial State


First off, I’m using the Pulse Engine v3.0 in Unity. I created a Pulse System prefab using the VitalsMonitor and PulseEngineDriver objects from the VitalsMonitor demo scene. I dropped that prefab into a new scene and loaded the StandardFemale@0s2 initial state file as a .txt file. Everything works great and I’m able to trigger the included actions through the Pulse Action On Click script. What I’m wondering is how to return to a normal, steady state similar to the initial state (perhaps even somewhat elevated from the initial state) during runtime. Specifically, I have a scenario where Tension Pneumothorax is triggered and I’m wondering how I can return the simulation to a steady state from that. I’ve tried triggering needle decompressions and other actions but nothing has had the desired effect.

Thanks in advance!


Glad you are having a good experience with Pulse.

You can set the severity of the tension pneumothorax to 0 and this will remove the action completely. However, think of the Pulse patient as an actual patient. The damage done to the patient’s physiology from the pneumothorax will last for a time. For example, if the oxygen saturation has dropped, it may take several minutes for it to return to normal and to do so the respiration rate and heart rate may increase. So returning to the pre tension pneumothorax vitals may not be possible. When you treat the tension pneumothorax with a needle decompression, the lung reinflates and the vitals should start to approach a more “normal” level, but they will still not return to a pre injury state because there is still an injury even if it is treated at some level.

I hope that helps and makes sense. Let me know if you need more help or clarification.


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Hi Rachel!

Thanks for you swift response.

I had tried adjusting the severity value for the tension pneumothorax but didn’t think it had done anything. I tried again and gave it some time and I see now that it works exactly as you described. Combining that with a needle decompression is giving me the results I’ve been expecting.

Thanks again,

It’s also worth noting that you could just load the same initial state over again.
You might have to refactor how you use the Pulse engine in your own scripts.
This may also create a undesired ‘resetting’ in the vitals monitor as well…

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Thanks for the tip! I’ll keep it in mind.

Another important thing to keep in mind is that you’ll need to do a chest occlusive dressing action before needle decompression if it’s an open tension pneumothorax. If it’s closed, just needle decompression should suffice.

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I’m not seeing the Chest Occlusive Dressing action. Is it listed under a different name or is that a functionality I would need to add from the C++ library?

It is included in the Managed Pulse.dll in the asset and is packaged under the Pulse.CDM namespace
You can see the definition here

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Oh awesome! Do I need to do anything besides add a new enum and case entry in PulseActionOnClick.cs to utilize it?

Yeah, you can add new enums to add it and remove it, and update the switch statement with new cases

Note that the the PulseActionOnClick file is really to demonstrate how to use the actions.
The editor interface is pretty simplistic and there only to demonstrate what pulse can do as we do not expose any way to input values for an action, like severity or something…

You can always extend our editor controls to do so if you like!

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Awesome! Thanks so much for your help!

So, I actually do have another thing I’d like to clarify about this, just to make sure I’m using it properly. Should I be seeing improved vitals after applying chest occlusive dressing and/or needle decompression without first setting the pneumothorax severity to zero?

The PulseOnActionClick is an Open Pneumothorax with a severity of 0.65
You need to run for a few minutes for the patient to degrade
The HR will go way up, and the SpO2 will drop below 92
Apply the Chest Wrap and The Needle and the HR will lower and the SpO2 will increase to the mid-upper 90’s

Again, the transitions do take time, its not instantaneous

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It may be a bit easier to experiment with Pulse using the Explorer application
You can do a lot more and get more log information

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Got it, thanks, Aaron! I’ll give that a shot.

You can see an example of the effect of increasing severities of pneumothorax and recovery after chest occlusive dressing and needle decompression in the respiratory validation documentation. See the Pneumothorax section here:

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