THE ISOCAPNIA RESEARCH LABORATORY

Toronto General Hospital

University of Toronto

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Welcome to our laboratory!

The purpose of this website is to provide a venue for our laboratory to share the results of our scientific work with our colleagues, clinicians and other researchers and create a forum for discussion of issues of mutual interest with visitors to our web site.

Who are we?

We are a group of physicians, scientists, engineers and students working in the field which can be broadly categorized as cardiorespiratory physiology. Our laboratory is located in the 14th floor of the Eaton Wing in the Toronto General Hospital. The principle investigator is Joseph A. Fisher, MD FRCP (C) who is a staff anesthetist at the University Health Network, and Professor in the Faculty of Medicine at the University of Toronto in Canada. Feel free to browse our biographies in the meet the staff section.

We have divided our research in two major categories, Clinical Applications and Research Applications, while the section on Theory explains the principles behind isocapnia.

To download the LabVIEW lung model illustrating isocapnia please right click here and "save target as"

(You will also need to download the "LabVIEW Runtime Engine" to run the simulator. LabVIEW Runtime Engine 7.1.zip

What is isocapnia?

The word isocapnia means "constant carbon dioxide level" and it refers to the pressure of carbon dioxide (PCO₂) in the alveoli. When breathing normally the average person has a consistent PCO₂ of about 40 mmHg due to the body's constant metabolism. However, if one increases or decreases one's ventilation, the PCO₂ can either fall or rise, either of which could be quite dangerous. Thus, PCO₂ is closely tied to ventilation. For many clinical and research applications, it would be desirable to isolate PCO₂ despite changes in minute ventilation ie. maintain isocapnia.

We have devised simple breathing circuits that allow patients to breathe spontaneously at any level above normal without affecting the arterial PCO₂. As a result, we are able to control levels of CO2 in the blood independent of a patient's breathing pattern. Our breathing circuits have helped develop our understanding of breathing in general, and that understanding - in turn - has allowed us to build better devices for both research and patient care.