Raising the blood pressure in the pulse engine

Pulse Physiology Engine
1

Hello everyone,

I am working with the Pulse Physiology Engine and trying to adjust the blood pressure of the patient. Could you please clarify which patient actions or parameters can be modified to increase blood pressure within the engine?

Even when simulating very high heart rates (e.g., 140 hr/min), I am observing a blood pressure reading of 110/83 mmHg, which seems lower than expected. Any insights into how blood pressure is influenced or any suggestions for adjusting this would be greatly appreciated.

Thank you!

2

The Pulse Physiology Engine is physics-based and simulates physiological responses mechanistically as much as possible. This means there are often no direct ways to set specific properties like blood pressure, as these arise from the interactions of the cardiovascular system’s components.

The MeanArterialPressureBaseline patient property can be adjusted to set the initial or healthy baseline blood pressure for the patient.

Blood pressure changes dynamically based on resistance modifiers applied in the cardiovascular model. For example:

  • The CardiovascularModel::AdjustVascularTone function adjusts resistance based on factors like baroreceptors, metabolic responses, or drug pharmacodynamics.
  • The CardiovascularModel::PleuralCavityVenousEffects function modifies resistance due to conditions like increased positive end-expiratory pressure (e.g., during mechanical ventilation) or mediastinum shift (e.g., pneumothorax).

Blood pressure is sensitive to total blood volume. Insults such as hemorrhage or dehydration, which reduce blood volume and lower blood pressure. Conversely, increasing blood volume through simulated fluid resuscitation may elevate it.

As a last resort, you can use direct resistance and compliance multipliers in the cardiovascular circuit. Example usage is provided in HowTo-CardiovascularModification.cpp. However, these modifiers are not tied to any underlying physiological mechanism and may produce less realistic results. They should be used sparingly and only if necessary for your specific application.