Device and Method for Intravascular Imaging and Sensing

Abstract

An intravascular sensor device can be used to guide treatment of a diseased blood vessel in the body of a patient. In some examples, the intravascular sensor device includes a pressure sensor and an ultrasound transducer. The intravascular sensor device is used to measure a pressure within the diseased blood vessel and acquire an ultrasound image of the diseased blood vessel. The pressure may be measured during hyperemic blood flow that is caused by a pharmacologic vasodilator drug. The measured pressure can be used to calculate a fractional flow reserve value. The ultrasound image can be used to determine a physical dimension of the blood vessel, such as cross-sectional area. The fractional flow reserve value and physical dimensions of the blood vessel can be used to optimize patient treatment.

What is claimed is: 
     
         1 . A method of determining a condition of a blood vessel, using a guide wire and a catheter comprising an ultrasound transducer array and a pressure sensor, comprising:
 with a single insertion of the catheter:
 performing at least one pressure measurement; and 
 imaging an area of interest of the blood vessel; 
   wherein, during the pressure measurement, a reduced cross-sectional area along a portion of the catheter reduces an influence of the catheter on the pressure measurement, enabling a more indicative pressure measurement.   
     
     
         2 . The method of  claim 1 , further comprising performing the at least one pressure measurement during a hyperemic blood flow rate caused by a pharmacologic vasodilator drug. 
     
     
         3 . The method of  claim 2 , further comprising determining, with a processor, a fractional flow reserve value based on the at least one pressure measurement during hyperemic blood flow. 
     
     
         4 . The method of  claim 1 , wherein the blood vessel comprises a lesion. 
     
     
         5 . The method of  claim 1 , further comprising determining, with a processor, a physical dimension of the blood vessel wherein the physical dimension is one of a cross-sectional area of the blood vessel, a diameter of the blood vessel, and a length of the blood vessel. 
     
     
         6 . A method of evaluating a stent within a blood vessel, using a guide wire and a catheter comprising an ultrasound transducer array and a pressure sensor, comprising:
 with a single insertion of the catheter:
 performing a pressure measurement; and 
 imaging an area of the blood vessel including the stent; 
   wherein, during the measurement of pressure, a reduced cross-sectional area along a portion of the catheter reduces an influence of the catheter on the pressure measurement, enabling a more indicative pressure measurement.   
     
     
         7 . The method of  claim 6 , further comprising performing the at least one pressure measurement during a hyperemic blood flow rate caused by a pharmacologic vasodilator drug. 
     
     
         8 . The method of  claim 7 , further comprising determining, with a processor, a fractional flow reserve value based on the at least one pressure measurement during hyperemic blood flow. 
     
     
         9 . The method of  claim 6 , further comprising determining, with a processor, a physical dimension of the stent wherein the physical dimension is one of a cross-sectional area of the stent, a diameter of the stent, and maximum distance between stent and blood vessel wall. 
     
     
         10 . A method comprising: inserting an intravascular sensing device into a body of a patient; controlling the intravascular sensing device to acquire at least one pressure measurement within a blood vessel; and controlling the intravascular sensing device to acquire at least one ultrasound image within the blood vessel. 
     
     
         11 . The method of  claim 10 , further comprising performing the at least one pressure measurement during a hyperemic blood flow rate caused by a pharmacologic vasodilator drug. 
     
     
         12 . The method of  claim 11 , further comprising determining, with a processor, a fractional flow reserve value based on the at least one pressure measurement during hyperemic blood flow. 
     
     
         13 . The method of  claim 10 , wherein the blood vessel comprises at least one of a lesion and a stent. 
     
     
         14 . The method of  claim 10 , further comprising determining, with a processor, a physical dimension of the blood vessel wherein the physical dimension is one of a cross-sectional area of the blood vessel, a diameter of the blood vessel, and a length of the blood vessel.