Apparatus and method for intravascular measurements

Abstract

Intravascular diagnosis apparatus and methods are disclosed. In one aspect of the disclosed technology, a monitoring guidewire includes a core wire having or made of one or more of MP35N, L605, Elgiloy, and an alloy of nickel, cobalt, molybdenum and chromium, a sensor disposed in a distal region of the core wire, and a housing substantially coextensive with the core wire and surrounding the core wire, the housing being more flexible than the core wire for at least the distal portion of the housing.

1 - 22 . (canceled) 
     
     
         23 . A monitoring guidewire comprising:
 a core wire made of at least one of: MP35N, L605, Elgiloy, or an alloy of nickel, cobalt, molybdenum and chromium;   a sensor disposed in a distal region of the core wire;   a housing surrounding the core wire; and   at least one signal wire connected to the sensor and positioned within the housing,   wherein the core wire and the housing together have a torque response that approximates a torque response of a 0.014 inch workhorse guidewire.   
     
     
         24 . The monitoring guidewire of  claim 23 , wherein the housing is more flexible than the core wire for at most a 40 cm length of the distal portion of the housing. 
     
     
         25 . The monitoring guidewire of  claim 23 , wherein the housing is more flexible than the core wire for an entire length of the housing. 
     
     
         26 . The monitoring guidewire of  claim 23 , wherein the core wire has a diameter of at most 0.007 inches. 
     
     
         27 . The monitoring guidewire of  claim 26 , wherein the housing comprises a hypotube having an outer diameter between 0.013 and 0.014 inches. 
     
     
         28 . The monitoring guidewire of  claim 27 , wherein the hypotube has an inner diameter less than 0.011 inches. 
     
     
         29 . The monitoring guidewire of  claim 27 , wherein the housing further comprises an intermediate coil, a protective structure surrounding the sensor, and a distal coil. 
     
     
         30 . The monitoring guidewire of  claim 27 , wherein the housing further comprises a protective structure surrounding the sensor, and a distal coil. 
     
     
         31 . The monitoring guidewire of  claim 27 , wherein the housing further comprises a hypotube of approximately 150 cm in length, an intermediate coil, a laser etched hypotube, and a distal coil.