Breathing New Life Into Patient Vascular Health

RespirAct® is a computer-controlled gas blender used to provide accurate, repeatable, non-invasive control of blood gases to stimulate vascular reactivity. It monitors blood flow responses in conjunction with diagnostic imaging techniques to show areas of hemodynamic compromise.

RespirAct® has been cited in over 150 articles published in peer reviewed journals.

RespirAct® is used in research being conducted at over 65 of the world’s leading research institutes, adding to the body of knowledge that will change patient care.

Generates Consistent and Standardized Stimulus

RespirAct® is a computer-controlled gas blender to implement precise control of PCO2 and PO2 for a consistent and repeatable stimulus.

Compatible with an MRI Environment

MRI Conditional – A portion of the system remains in the control room and communicates with a unit which is placed next to the MRI bed. RespirAct® can also be used with Transcranial Doppler (TCD) and other imaging modalities.

Simple and Intuitive User Interface

RespirAct® is controlled through a user-friendly graphical interface requiring minimum training.


RespirAct® is designed with fail safes and there is no potential of inadvertent hypoxic gas administration.


RespirAct®, including RespirAct® RA-MR™ and RespirAct® Clinical, has not been cleared by the FDA and does not have CE mark. In these jurisdictions, RespirAct® is distributed by Thornhill Medical to collaborators for use in IRB approved basic physiological research studies. The RespirAct® system is not intended to be used in the diagnosis or treatment of disease and is not intended to be used in studies that evaluate that evaluate its safety or efficacy. RespirAct® Clinical is Health Canada approved.