Focused rotational ivus transducer using single crystal composite material

Abstract

An ultrasound transducer for use in intra-vascular ultrasound (IVUS) imaging systems including a single crystal composite (SCC) layer is provided. The transducer has a front electrode on a side of the SCC layer; and a back electrode on the opposite side of the SCC layer. The SCC layer may have a dish shape including pillars made of a single crystal piezo-electric material embedded in a polymer matrix. Also provided is an ultrasound transducer as above, with the back electrode split into two electrodes electrically decoupled from one another. A method of forming an ultrasound transducer as above is also provided. An IVUS imaging system is provided, including an ultrasound transducer rotationally disposed within an elongate member; an actuator; and a control system controlling activation of the ultrasound transducer to facilitate imaging.

What is claimed is: 
     
         1 . An ultrasound transducer for use in intra-vascular ultrasound (IVUS) imaging systems, the transducer comprising:
 a single crystal composite (SCC) layer;   a front electrode on a side of the SCC layer; and   a back electrode on the opposite side of the SCC layer; wherein:
 the SCC layer includes pillars made of a single crystal piezo-electric material; 
 the pillars are embedded in a polymer matrix; and 
 the SCC layer has a concave upper surface and an opposing convex lower surface. 
   
     
     
         2 . The ultrasound transducer of  claim 1  further comprising an impedance matching layer of a thickness about ¼ wavelength of a center frequency of an ultrasound signal transmitted by the transducer. 
     
     
         3 . The ultrasound transducer of  claim 1  wherein the pillars have an aspect ratio of at least 2. 
     
     
         4 . The ultrasound transducer of  claim 1  wherein the pillars have a thickness of about 50 μm or less. 
     
     
         5 . The ultrasound transducer of  claim 1  wherein the pillars cover an area of about 25% of a surface area of the SCC layer. 
     
     
         6 . The ultrasound transducer of  claim 1  wherein the pillars have a cross section on a surface of the SCC layer with a shape selected from the group consisting of a circle, a square, a rectangle, and a figure from a random pattern. 
     
     
         7 . The ultrasound transducer of  claim 1  wherein the back electrode is split into two electrodes electrically decoupled from one another. 
     
     
         8 . An IVUS imaging system, comprising:
 an elongate device sized and shaped for insertion into a vessel of a patient, the elongate device including an ultrasound transducer that includes:
 a single crystal composite (SCC) layer; 
 a front electrode; and 
 a back electrode; wherein:
 the SCC layer includes pillars made of a single crystal piezo-electric material; 
 the pillars are embedded in a polymer matrix; and 
 the SCC layer has a concave surface and an opposing convex surface. 
 
   
     
     
         9 . The IVUS imaging system of  claim 8 , wherein the ultrasound transducer is disposed within a distal portion of the elongate device and rotatable with respect to a body of the elongate device. 
     
     
         10 . The IVUS imaging system of  claim 9 , further comprising an actuator coupled to the ultrasound transducer, the actuator configured to rotate the ultrasound transducer relative to the body of the elongate device. 
     
     
         11 . The IVUS imaging system of  claim 10 , wherein the actuator includes a motor and is coupled to the ultrasound transducer via a drive shaft. 
     
     
         12 . The IVUS imaging system of  claim 8 , further comprising a control system configured to control activation of the ultrasound transducer to facilitate imaging. 
     
     
         13 . The IVUS imaging system of  claim 12 , wherein the control system is further configured to process ultrasound echo data received by the ultrasound transducer to generate a cross-sectional image of the vessel. 
     
     
         14 . The IVUS imaging system of  claim 12 , further comprising a display in communication with the control system. 
     
     
         15 . The IVUS imaging system of  claim 8 , wherein the elongate device is a catheter.