Investigating brain health using non-invasive imaging

Observed – Cerebrovascular blood flow and peripheral blood pressure and ECG waves. Two observation methods of Cerebrovascular blood flow over two days of observation. Transcranial Doppler (TCD) and Near-infrared spectroscopy (NiRS) In the first imaging session, all subjects will undergo 60 minutes of NiRS imaging. After the setup process, the NiRS data will be collected during 5 minutes of resting state of sitting position. During NIRS recordings subjects will wear a non-invasive chest strap containing an EquivitalTM EQ02 LifeMonitor to monitor respiration, heart beat. After the NIRS session, subjects will be asked to answer a questionnaire about their daily activity and their height and weight will be measured to assess their cardiorespiratory fitness. In the second imaging session, the transcranial Doppler device will be used to measure blood flow in middle cerebral arteries. Once a steady-state cerebral blood flow velocity is achieved, a 5-minute beat-to-beat recording will be obtained with blood pressure measured 3 times during this interval. The two imaging sessions will be carried out on 2 consecutive days. For each subject, the NiRS imaging will take place at Hunter medical research institute imaging centre for a total of one hour. The TCD imaging will take place at the Clinical Nutrition Research Centre at the University of Newcastle’s Callaghan campus for one hour.