Measuring active muscle oxygenation and blood flow non-invasively during dynamic physical activity

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This proposal requests funds to purchase an Optical Monitor of Metabolic Rate of Oxygen Consumption (MetaOx) to explore how individuals match oxygen delivery to oxygen demand during physical activity in order to identify and understand how and why individualized strategies and outcomes exist in the oxygen delivery pathway. Requested equipment: The MetaOx is a non-invasive monitor combining measures of active tissue oxygenation (frequency-domain near infrared spectroscopy) and blood flow (diffuse correlation spectroscopy). This monitor will be the first within an exercise physiology laboratory within Canada and the second within the nation. What it will be used for: This monitor will form a broad backbone of my research program and will be utilized within a novel experimental approach focusing on differences between individuals in how the heart and blood vessels match oxygen delivery to oxygen demand. When people perform physical activities like walking, running or cycling, oxygen delivery must be matched to the muscle's oxygen demand. Coordinated responses between the heart and blood vessels help facilitate an optimal matching and allow these activities of daily living (ADL) to be well-tolerated. Enabled activities: This monitor will allow for non-invasive measurement of active muscle oxygenation and blood flow during dynamic movements reflective of ADL including treadmill walking, running, or cycling while allowing direct knowledge translation from the laboratory to the real-world. Presently, to assess active muscle oxygen delivery, my laboratory measures muscle blood flow non-invasively by arterial echo and Doppler ultrasound while venous blood samples provide a measure of oxygen extraction by the active muscle. However, the use of ultrasound requires isometric contraction in which the joint and limb do not move. This does not reflect the true state of dynamic muscular movements common to ADL and also assesses `bulk' limb blood flow as opposed to active muscle specifically. With this monitor, my laboratory will be able to deconstruct the oxygen delivery pathway from the mouth to the muscle, while enabling a paradigm shift in the scientific approach by focusing on unique individual responses. Impact and significance: Identifying how and why individualized strategies and outcomes exist in the oxygen delivery pathway is important for, and applicable to, the Canadian population at large and represents a critical missing link in understanding the control of blood vessel dilation, the individual capacity to perform physical activity, and the vulnerability to exertional intolerance. Application of the requested equipment will create the foundational knowledge required to inform strategies of targeted, personalized or `precision' interventions, similar to the emerging field of personalized medicine, to improve the lives of all Canadians ranging from high performance exercise through to rehabilitation settings.