Major upgrade and finetuning of EDRF simulation, including a stroke volume animation.

Endothelium derived relaxing factor (or NO) is released by the endothelium in response to the shear stress of blood forced through the arteries. Distal arteries will dilate when EDRF is high but constrict when EDRF is low. Arterial Acceleration forces the blood into peripheral tissue even when tissue conditions are suboptimal, for instance when tissue pressure is elevated. The model shows how arterial acceleration nevertheless forces blood into such tissue enabling the release of EDRF that will subsequently cause vasodilation further downstream. In this way EDRF helps to distribute the penetration of the pressure wave more evenly over the different branches of the arterial tree.

Expanded the stroke volume simulation to the small circulation (via the lungs).

Did you ever have difficulty explaining to your students what is the difference between actual blood flow and the propagation of the arterial pressure wave? Neuromon's cardiovascular simulation app makes this clear by showing an animation of the stroke volume working its way through the arterial tree. The propagation of the pressure wave generated by the heart ejecting blood volume into the aorta is much faster than the actual movement of blood. It is enhanced by arterial acceleration..

In this version all presenting windows have been made sizable. Several improvements have been made on modeling the situation during cardiac arrest. A cessation of breathing during cardiac arrest was added to the model as well as the option of artificial breathing. The app is further being improved for macOS Tahoe and Swift 6.

There was an issue with the controls in macOS Tahoe 26 caused by erroneous labeling of layers. Problem resolved.

In version 1.11 several new features have been added. In order to demonstrate the validity of the model the ejection phase can optionally be chosen as block puls instead of sinusoidal pulse. This gives a better impression about the viscoelastic properties of the model. Two new ways of graphing multiple signals have been added: a superimposed option for a better assessment of the change in flow profile over the length of the arterial tree and an option to graph the raw signals underlying the average pulse wave calculated over 10 seconds in the NMA window The list of possible scenarios was expanded with Valsalva manoeuvres and a hypothetical simulation of a migraine attack.

This version is enriched with historical citations on cardiovascular physiology.

Added Z-score interpretation window; fixed minor bugs; added sound of aorta stenosis.

With this update we have added the option to display flow in selected branches of the arterial tree. Also an extra graphical view was created to display flow in four consecutive branches of the arterial tree. The display of Z-scores was expanded with the display of previous analysis results, gradually fading out when becoming more outdated. The option was added to have unilateral increase in intracranial pressure.

In version 1.7 several improvements have been made to the model display (removing ragged edges), to the reflexes (in agreement with recent experimental data on CO2 reactivity) and a time graph of cardiac output was added. Several minor errors have been resolved.

In this version we have added the option to resuscitate at cardiac arrest: just move the mouse over the heart symbol and see it change in a hand symbol. Then press the mouse in the appropriate rhythm and speed. Furthermore we have added detailed analysis of NMA waveforms with the option to explore the relation between arterial blood pressure and middle cerebral artery flow velocity. These graphs show the different behavior of PI and PaR during intracranial pressure elevation.

This is a substantial update with extra graphs enabling the comparison of flow and pressure waveforms. For education reasons a scenario is added simulating cardiac arrest. An extra gap has been added to display CO2 reactivity. A window has been added to report on the model's mutable and immutable parameter values. Some bugs in the patient monitor have been resolved.

This version brings further finetuning of the model, heart beat sounds as alternative to monitor sounds, improved monitor display and improved overall performance.

Many improvements have been made: inclusion of NMA for waveform analysis and PaR for early detection of intracranial pressure elevation. Also the shape of the waveform is automatically adjusted for age. Pathological states such as orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS) have been included. Trend graphs of arterial blood pressure and middle cerebral artery flow velocity have been included as for the PaR.

Small bug fixes causing the program to halt. Correction program information. Added pressure indication bars to model volumes. Added trend graph for ABP and HR.

NEW! This update includes a Patient Condition window with a graphical display of the virtual patient. Furthermore a Patient Monitor is simulated, giving the main hemodynamic parameters on a simulated monitor screen.

Retuned the different reflexes. Improved screen layout. Corrected app icon. Added automatic adaptation of respiratory rate and acceleration. Adjustable timebase for graphs of cerebral blood flow and arterial blood pressure. Corrected several bugs.