Frequently Asked Questions


What is HumMod?

HumMod is an interactive mathematical model of human physiology.  It uses XML to describe the mathematics of human physiology.

How was HumMod developed?

Arthur Guyton realized in the 1950s and 1960s that physiology could only be truly understood by considering it as a coherent whole.  He and his student, Thomas Coleman, developed a large integrative model of human circulatory physiology.  Dr. Coleman continued this project, adding organ systems, metabolism, and interventions culminating in QCP (Quantitative Circulatory Physiology), QHP (Quantitative Human Physiology), Digital Human, and the most recent version, HumMod (Human Model). 

Who developed HumMod?

Dr. Tom Coleman, Dr. Robert Hester, and Dr. Richard Summers

What sources were used to make the mathematical model of HumMod?

Sources are listed at http://www.zotero.org/groups/hummod_references

Are there any other programs like HumMod?

HumMod is similar to programs like QCP, but is attempting to build upon that program.


Do I need a certain operating system to run HumMod?

At this time, you will need a Windows operating system to run HumMod.  A browser based application is being developed to eliminate discrepancies with operating systems.

Is there a web-version of HumMod?

One is in preparation.  You'll like it.  Here's a web-version of the Minis.

How do I download HumMod?

  • Click this link
  • HumMod will appear in your computers downloads folder under a compressed file named HumMod-hummod-standalone-v1.6.1-1-g2d02143.zip. 
  • Copy the folder into a directory of your choice then unzip the folder. 
  • Open the first folder (the one you just unzipped) and the folder inside of it. 
  • You should now see several folders and files with "Benchmark" at the top. 
  • Click on the HumMod.EXE application file to open HumMod for you. 
  • After it parses, the "Chart" tab should appear and you can now use HumMod. 
  • If you have any questions about running HumMod after it is opened please see the User's Manual.

Is there an online manual or examples on how to use HumMod?

There is a user’s manual that should be available for download shortly.

Interacting with HumMod

How do I monitor the "patient"?

There is a general overview of how the patient is feeling like the “temperature” and “heart rate” which can be found under the “Chart” tab.  Other tabs contain more specific material; some of this is clinically obtainable information such as blood gases, serum hormone concentrations, etc.  Other tabs contain information that is not readily obtained in live patients, i.e. contents of the renal tubule, stored amounts of various hormones, individual tissue perfusion, etc.

Can I search for specific variables or quantities?

Yes. A tool named "Towel" has been developed that will allow users to search for variables and quantities. This tool will not automatically direct users to the location they desire, but will offer the necessary tab and panels they must follow to find what they are searching.

Does HumMod offer a reference table of typical physiological values for both males and females?

Yes, just click the informational “i” boxes in each data table.

Does HumMod notify me if the patient is developing physiological problems?

Not specifically, but you should receive general updates about the health of the patient (i.e. “Your patient is convulsing.”) which should give you some indication about the health of your patient’s organs and other systems.  These messages come in response to ischemic conditions, painful stimuli, or drugs that cause decreased mental awareness.

What happens to the program if the patient dies?

The program will give you a warning that the patient is dead allowing you to stop the program and examine the patient. If you continue to run the program after the patient dies then the program may crash.

Can a patient recover from stresses/stimuli he is exposed to?

A patient will recover from most stresses you place it under given adequate time.

Does regular exercise or long-term lethargy affect overall fitness level? If I simulate a patient who runs daily for 30 minutes over the course of a 30 day simulation, is the patient capable of running further/longer than a patient who runs at a slower rate, for less time, less regularly, or not at all?

No, the patient does not accumulate any level of fitness or “lose weight” by exercising or performing any other similar task for a long period of time.

Can HumMod only model a patient for so long? (Does HumMod lose accuracy and/or reliability as the program simulates time?)

No, this program can simulate any patient for an infinite amount of time assuming the patient is at a steady state (There is no factor causing the patient to die).

Are actions taken simulated over time or are they a single point in time?

Most actions (onset of a hemorrhage, acute heart failure, renal stenosis, dietary change) are instituted on an immediate basis.  Actions such as drug injection or progressive heart failure have a built-in delay to allow gradual onset.

What drugs can be administered to a patient?

You can administer any number of drugs to a patient if you know what the drug will affect. For instance, if drug A will affect some aspect of a patient’s physiology, instead of directly administering that drug through a button labeled “drug A,” you can instead directly manipulate that aspect of the physiology. However, there are a few drugs that are offered on HumMod.

Is there any way to incorporate certain medical conditions (e.g. sickle cell, HIV/AIDS, pregnancy, etc.) into the patient’s model?

At this time, there is no provision for these particular diseases.  However, HumMod can model progressive heart failure, renal stenosis, Type I diabetes, and many other medical conditions.  In addition, acute events such as pneumothorax, hemorrhage, and heart failure are supported in HumMod.

Age and Race

Why does HumMod default to a 37 year old male?

Currently, there is a large body of research available for adult males, which allowed HumMod to be developed accurately. Also adult varies little until geriatric age, making 37 years old an ideal age for HumMod.

What age ranges can be used by HumMod?

Currently, there is only one age offered by HumMod, 37, despite the presence of a slidebar suggesting that age can be adjusted. At this time, tools are being developed to expand the age range that HumMod can model.

Does variance from the default age, 37, and/or gender affect the reliability and accuracy of the data returned?

Variance should not affect the reliability and accuracy of your data.

Is patient race included?

Not explicitly.  Many parameters can be adjusted, allowing the approximation of individual phenotypes.

Saving Solutions

How do I save a solution in HumMod?

There are two distinct types of saved files in HumMod.  The first is the "initial condition" file.  An initial condition file is a solution that is run to certain point and then saved.  On re-opening, time and physiolgical is the same as when saved, but previously recorded data is not shown. There is a way to reset time when you save an initial condition by clicking Options, Saving ICs, set dependent variable to it's initial value. The second type of file is a Solution file. Solution files are saved like initial conditions files, but with the suffix .SOL. When reopened, HumMod display the outcome of the simulation with all previously recorded physiological data available. However, the time record is reset to 12:00 AM Day 1.

How do you undo a last change made in HumMod such as a change in time or physiology?

Load a previously saved solution or initial condition. If you advance time there is no way to reverse it. If you made a change in physiology, it can generally be undone on the same panel, however it may cause a transient in the solution.

Is there any way for me to see all the changes made to the patient on one page?

No, but you should be aware of the changes that the patient should undergo based on what variables you changed.

Future development

What factors or variables do you plan to include later on?

We hope to add a second kidney and a baby model into HumMod in the near future. Of course, we always strive to make HumMod a more complete model of the human body and physiology.

Will there be animation in the future to support HumMod?

That is a possibility that is being explored at this time.

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