A three-dimensional (3D) sizing tool for cardiac assessment is disclosed. An example system may display a representation of a three-dimensional vascular model including a three-dimensional (3D) sizing tool that surrounds a portion of the three-dimensional vascular model, wherein the portion comprises a volume of the three-dimensional vascular model for which to determine a mapping of geometrical information to a length along the portion; display an interface for adjusting the 3D sizing tool, wherein an area along the interface corresponds to a length of the 3D sizing tool; receive input to adjust the length of the 3D sizing tool via the area along the interface; and adjust the length of the 3D sizing tool according to the input.

Various embodiments described herein relate to determining flow occlusion in microfluidics using digital holography. In this regard, various embodiments provide for receiving two or more images of a plurality of blood cells transiting one or more microfluidic channels of an occlusion device, determining a presence indication for blood cells within the one or more microfluidic channels based on at least one image of the two or more images, determining a movement indication for the blood cells within the one or more microfluidic channels based on the two or more images, and generating an occlusion status for the one or more microfluidic channels based on the presence indication and the movement indication.