Physiology sensing intraluminal device with index for spectral flow assessment, and associated devices, systems, and methods

An apparatus, comprising:

• an intravascular guidewire configured to be positioned within a blood vessel of a patient, wherein the intravascular guidewire comprises a blood flow sensor;
• a processor circuit configured for communication with the blood flow sensor, wherein the processor circuit is configured to:
• control the blood flow sensor to perform a plurality of velocity measurements of blood flow within the blood vessel;
• generate a velocity spectrum based on the plurality of velocity measurements;
• calculate an index representative of a shape of the velocity spectrum, wherein the shape represents the plurality of velocity measurements at a particular alignment of the blood pressure sensor in the blood vessel such that the index indicates alignment of the blood flow sensor relative to the blood vessel;
• calculate a blood flow parameter using the plurality of velocity measurements when the index satisfies a threshold, wherein the blood flow parameter is different than the index;
• and
• provide the blood flow parameter to a display in communication with the processor circuit.