The US-CHIMP project successfully conducted several significant activities and achieved important milestones, structured around three key technical and scientific work packages:
Work Package 1: 3D Ultrasound Imaging Methods of Optic Nerve Sheath Diameter
• Developed and fully validated a novel, semi-automated 3D ultrasound technique for accurate quantification of the optic nerve sheath, a critical indicator of intracranial pressure.
• Created robust software and algorithms for freehand 3D ultrasound imaging, significantly reducing variability and user dependence compared to traditional 2D techniques.
• Demonstrated that 3D measurements are independent of observer alignment and geometric assumptions, thereby improving the accuracy, reliability, and reproducibility of optic nerves sheath assessments.
• Introduced new diagnostic markers such as optic nerve sheath thickness, uniformity, and eccentricity, with thickness identified as the most sensitive indicator of intracranial pressure changes.
• Achieved full validation of the method, with outcomes currently under peer review at the highly-ranked journal Investigative Radiology and scheduled presentations at IEEE International Ultrasound Symposium 2025.
Work Package 2: Wave Intensity Analysis (WIA) and Hemodynamic Model of Cerebral Hypoxia
• Developed a computational model (1D Vascular Network Simulator) for simulating cerebrovascular hemodynamics under hypoxic conditions
• Created algorithms and a graphical user interface for real-time capture and analysis of cerebral blood flow and vessel diameter data.
• Conducted preliminary human studies showing WIA’s potential in detecting cerebral vascular changes caused by hypoxia, hypercapnia, and cold exposure.
• Presented initial findings at the Danish Cardiovascular Academy Winter Meeting (2025), highlighting WIA’s effectiveness in identifying physiological responses indicative of cerebrovascular stress.
Work Package 3: Validation in Human Subjects
• Successfully completed human volunteer studies validating developed techniques under controlled hypoxic conditions at the terraXcube facility.
• Led and collaborated in multiple studies to evaluate cerebral responses to hypoxia, cold, and combined stressors.
• Identified critical limitations in existing literature regarding 2D ONSD measurements, emphasizing the need for 3D imaging and automated measurement protocols.
• Developed a comprehensive understanding of the interaction between hypoxia and cold exposure, providing critical insights into physiological mechanisms underlying cerebral hypoxia and associated conditions such as Acute Mountain Sickness.
