Grant: Research Tools and Instruments

The act of breathing is essential for human life. The inspiratory muscles (e.g., diaphragm, intercostals) support the exchange of oxygen and carbon dioxide. Locomotion is a key feature of mammalian life and the biology of exercise is a complex phenomenon. During physical exertion, breathing rate and depth increase and the inspiratory muscles work harder and receive greater blood supply to meet their metabolic requirements. But with a limited supply of blood within the body, the working locomotor muscles compete with the inspiratory muscles for oxygen delivery, leading to muscle fatigue and hindering exercise performance. The sensitivity of the inspiratory muscles to fatigue may differ between biological sex and depend on the relative blood supply. My research program is beginning to study whether inspiratory muscle blood flow differs between biological sex and contributes to sex differences in muscle fatigue. My existing ultrasound system is failing and a new ultrasound system with sophisticated ultrasound contrast detection technology is urgently needed for this research to advance. While various techniques exist to measure skeletal muscle blood flow in humans, they cannot be used to measure blood flow to inspiratory muscles located deep within the chest cavity. Contrast enhanced ultrasound is a promising technique that uses contrast agents added to the blood to determine muscle blood flow. My research team which includes leading international experts will be the first in the world to measure inspiratory muscle blood flow using contrast enhanced ultrasound in humans. This exciting methodology will permit significant scientific advancement in our understanding of respiratory muscle blood flow control in humans which largely relies on animal research. My research will also have widespread clinical application, particularly in critically ill patients where knowledge of inspiratory muscle blood flow could help make life or death decisions. Without this infrastructure, this research will not be possible. My diverse team of research personnel will receive hands-on training in contrast enhanced ultrasound offering highly transferrable skills to support career paths in academia or industry. Using this state-of-the-art technique, my research team will determine (1) the association between inspiratory muscle blood flow and respiratory work and (2) sex-based differences in respiratory muscle blood flow during fatiguing exercise. Without this equipment, my research team will not be able to advance their research. Outside of my research program, the requested equipment will support >45 highly-trained research personnel from 8 NSERC funded research programs. Additionally, the requested equipment will support the training of 30 research personnel across Canada as part of our biennial ultrasound summer school for health and exercise science.