BME PhD Preliminary Exam Announcement for Brianna Kish (Y. Tong and R. Shi, co-advisors) Everyone is invited to attend the public presentation beginning at 7:00 PM. Research title: Respiratory Modulation of HRV, Low-Frequency Oscillations, and Cerebrospinal Fluid Dynamics Date: December 10, 2025 Time: 7:00 PM EST, fully online, info below Topic: Brianna Kish's Prelim Exam Time: Dec 10, 2025 07:00 PM Eastern Time (US and Canada) Join Zoom Meeting https://purdue-edu.zoom.us/j/91343935708<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpurdue-edu.zoom.us%2Fj%2F91343935708&data=05%7C02%7Cbmeroundtable-list%40ecn.purdue.edu%7Cfac47d80722343a7be3808de2d326bf9%7C4130bd397c53419cb1e58758d6d63f21%7C1%7C0%7C638997891749975179%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=4sbgf4OxC8tyXgn1l3aNW5xMdL2uw379S%2FRUoEL7hxA%3D&reserved=0> Meeting ID: 913 4393 5708 Committee: * Yunjie Tong (Co-chair) * Riyi Shi (Co-chair) * Deva Chan * Qiuting Wen Abstract: Cerebrospinal fluid (CSF) flow is crucial in clearing metabolic waste from the brain, including amyloid-β and tau proteins. Impairments in CSF circulation, arising from sleep disruption, neurological injury, or disease, are associated with increased risk of neurodegeneration and cognitive decline. Although cardiac pulsation contributes to CSF movement, recent work demonstrates that slow, low-frequency oscillations (LFOs) in cerebral blood flow and autonomic activity strongly drive CSF transport. These observations suggest that CSF dynamics may be enhanced by intentionally modulating the physiologic oscillations that couple blood and CSF flow. Specifically, respiration alters heart rate variability (HRV), CO₂ dynamics, and vascular tone, all of which influence cerebral blood flow, and consequently, CSF. However, the mechanistic pathway linking low-frequency respiration to LFO enhancement and downstream CSF motion remains poorly understood. This project aims to determine whether controlled low-frequency respiration can amplify autonomic and vascular oscillations and thereby enhance CSF flow. Aim 1 will quantify how low-frequency breathing (<0.15 Hz) shapes HRV, blood pressure, and low-frequency cerebral blood flow oscillations using concurrent transcranial Doppler ultrasound, fNIRS, PPG, respiration monitoring, and blood pressure measurement. Aim 2 will test whether respiration-driven autonomic oscillations enhance CSF low-frequency power using fMRI with synchronized physiological recordings. We expect that slow breathing will entrain autonomic rhythms, increase LFO power in cerebral blood flow, and drive corresponding increases in CSF oscillations. Successful completion of this work will establish a non-invasive method to modulate CSF dynamics and lay the foundation for respiratory-based interventions to preserve brain health. -- Bmeroundtable-list mailing list Bmeroundtable-list@ecn.purdue.edu https://engineering.purdue.edu/ECN/mailman/listinfo/bmeroundtable-list