RespirAct™

Gas Control System

Thornhill Medical - Research

An investigative device used in diagnostic procedures which measure vascular reactivity.

 

The RespirAct™ is a computer-controlled gas blender providing carbon dioxide (CO2), oxygen (O2) and nitrogen for a subject to inhale while breathing for the purpose of controlling the concentrations of the respective blood gases.

 

 

Generation 4 RespirAct™ (RA-MR)

 

A totally re-designed hardware platform*, with new mode of action, running updated algorithms adding greater precision, reliability and safety to the targeting concentrations of CO2 and O2 in the lungs and blood.

*The preceding Generation III device is no longer available.

 

 

The Aim

 

Changing the concentration of CO2 and O2 in the blood in order to stimulate blood flow responses in organs (for example, the brain and heart). Monitoring blood flow response to blood gas changes in these organs reveals aspects related to their vascular beds.

RespirAct™
Research Enquiries


RespirAct™ CAPABILITIES

Physiology
  • System uses sequential gas delivery (SGD) (PMID 26840836)
  • **SGD is the only targeting method where PETCO2 = PaCO2. (animals, see PMID 23100168; 21647718; 14660515; 8349809; humans (PMID 18565992)**
  • The exact stimulus is therefore known with a sampling frequency equal to the breathing frequency!
Range

RespirAct™ can target blood gas concentrations over a wide range (PCO2 from 30 to 60+ mmHg; O2 from 40 to 600 mmHg).

Accuracy and Speed of Response

The accuracy is within 2 mmHg of target. Transition to a new level in a designated square wave is within 2 breaths.

Patterns

Box car, ramp, sinusoidal.

Versatility

The targeting of PCO2 and PO2 is independent of each other, which means the investigator can change one, or both, simultaneously, or sequentially.

Safety

There is no potential for the device to deliver a hypoxic gas or apply positive or negative airway pressure. In all errors or malfunction, room air is delivered to the subject.

Little Subject Cooperation Required

Targeting precision is largely independent of how hard the subject breathes or the pattern of breathing.

Data Acquisition

The RespirAct™ records inspired and exhaled gas concentrations, which can be recalled, analyzed and graphed.

Automated Function: “Plug and Play”

Thornhill Medical - Research

Small, and portable; easily stored, easily transported, MRI compatible, easily assembled, easy to set up prior to each test.

Thornhill Medical - Research

Automated algorithm to identify subject’s baseline parameters.

Thornhill Medical - Research

Targeting via designating or drawing graphic of the concentration and pattern of PCO2 and PO2.

Thornhill Medical - Research

Choose from multiple blood gas targeting patterns that are built-in: step, ramp, sinusoidal or any combination thereof; enter parameters (e.g., duration, starting point, amplitude etc.) and limits to pattern.

Thornhill Medical - Research

Designed for users with minimal technical expertise. A user manual and videos guide you through a simple set up process.

Thornhill Medical - Research

Full support by telephone, email, videoconferencing and personal visit to lab.

Important Note

The RespirAct™ has not been evaluated by the FDA and 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 its safety or efficacy.

Important Note

The RespirAct™ has not been evaluated by the FDA and 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 its safety or efficacy.

RESPIRACT™ RESOURCES

The CO2 stimulus for cerebrovascular reactivity: Fixing inspired concentrations vs. targeting end-tidal partial pressures.
The CO2 stimulus for cerebrovascular reactivity: Fixing inspired concentrations vs. targeting end-tidal partial pressures.

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Magnetic Resonance Imaging–Based Cerebrovascular Reactivity and Hemodynamic Reserve: A Review of Method Optimization and Data Interpretation
Magnetic Resonance Imaging–Based Cerebrovascular Reactivity and Hemodynamic Reserve: A Review of Method Optimization and Data Interpretation

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Assessing cerebrovascular reactivity abnormality by comparison to a reference atlas.
Assessing cerebrovascular reactivity abnormality by comparison to a reference atlas.

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