Apparatus for vessel characterization

Abstract

The invention discloses an apparatus (2), a system (1) and a method (100) for characterization of vessels and for vessel modeling. The cross sectional area (A1) of the vessel is derived from pressure measurements (p1,p2) obtained by an instrument (3) from within the vessel. When multiple cross sectional areas (A1,A2) are derived for multiple reference positions (r1,r2) based on pressure measurements (p1,p2,p3) along the vessel, a representation (20,30) of the vessel can be rendered, without requiring any imaging modality. Furthermore, the effect of the pulsatile blood flow on the elasticity of the vessel walls can be visualized, supporting assessment of a stenosis or an aneurysm formation along the vessel.

1 . An apparatus for assessing a vessel of a patient, the apparatus comprising:
 a processor configured to:
 receive, from an instrument positioned within the vessel, a plurality of pressure measurements corresponding to a plurality of locations within the vessel; 
 derive a first cross-sectional area for a first position of the vessel based on a first set of pressure measurements of the plurality of pressure measurements; 
 derive a second cross-sectional area for a different second position of the vessel based on a second set of pressure measurements of the plurality of pressure measurements; 
 generate a representation of the vessel based on the first cross-sectional area and the second cross-sectional area; and 
 output the representation of the vessel to a display in communication with the processor. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the processor is further configured to:
 receive morphological information of the vessel from an imaging unit;   generate a composite representation comprising:
 a morphological representation of the vessel based on the morphological information; and 
 the representation of the vessel based on the first and second cross-sectional areas and the first and second positions. 
   
     
     
         3 . The apparatus of  claim 1 , wherein the processor is configured to derive the first and second cross-sectional areas for subsequent phases of a pulsatile blood flow in the vessel. 
     
     
         4 . The apparatus of  claim 3 , wherein the representation of the vessel comprises a sequence of representations of the vessel corresponding to the subsequent phases of the pulsatile blood flow. 
     
     
         5 . The apparatus of  claim 1 , wherein the representation comprises a two-dimensional, longitudinal representation of the vessel. 
     
     
         6 . The apparatus of  claim 1 , wherein the representation comprises a three-dimensional representation of the vessel. 
     
     
         7 . The apparatus of  claim 1 , wherein:
 the first set of pressure measurements correspond to a first set of locations of the plurality of locations, and   the second set of pressure measurements correspond to a different second set of locations of the plurality of locations.   
     
     
         8 . The apparatus of  claim 7 , wherein:
 the first set of pressure measurements comprises a first pressure measurement corresponding to a first location and a second pressure measurement corresponding to a second location of the vessel, and   the second set of pressure measurements comprises a third pressure measurement corresponding to a third location of the vessel and one of the first pressure measurement or the second pressure measurement.   
     
     
         9 . The apparatus of  claim 8 , wherein the processor is further configured to ascertain the first, second and third locations based on a position of at least one marker component of the instrument. 
     
     
         10 . The apparatus of  claim 9 , wherein the processor is further configured to:
 identify a bend in the instrument based on the position of the at least one marker component of the instrument; and   generate the representation such that the representation visualizes the bend.   
     
     
         11 . A system for characterizing a vessel of a living being, comprising:
 the apparatus of  claim 6 ; and   the instrument comprising at least one pressure sensor configured for providing the first and second sets of pressure measurements at the plurality of locations within the vessel.   
     
     
         12 . The system according to  claim 11 , wherein:
 the at least one pressure sensor provides the first pressure measurement at the first location,   the instrument comprises a second and a third pressure sensor for providing the second and third pressure measurements at the second and third locations, respectively.   
     
     
         13 . The system according to  claim 11 , wherein:
 the instrument is configured to provide the first, second and third pressure measurements by subsequent changes of a position of the at least one pressure sensor along the vessel.   
     
     
         14 . The system according to  claim 11 , wherein the instrument comprises at least one of a pressure-sensing catheter or a pressure-sensing guidewire.