Percutaneous Catheter System and Method for Rapid Diagnosis of Lung Disease

Abstract

A percutaneously delivered medical device and its method of use includes a catheter, at least two electromagnetic sensing coils located within the distal tip of the catheter, and at least one within the proximal handle, and a multi-element planar ultrasound transducer array located within the distal tip of the catheter and configured to transmit and receive ultrasonic energy in at least two imaging modes. The device also includes an imaging system coupled to the ultrasound transducer and is used for creating an image of tissue in a first target plane that extends orthogonally from the catheter body. The medical device also includes a backscatter evaluation system for use in receiving and evaluating the acoustic spectral characteristics of tissues within a second target area within the first target plane.

What is claimed is: 
     
         1 . A medical device for operation by a physician user, in a patient's lung tissue having a suspected tumor, the medical device comprising:
 a) a catheter having an elongate catheter body terminating in a proximal handle and extending along an axis to a distal tip, said elongate catheter body adapted for delivery to lung tissue by insertion through a percutaneous needle;   b) at least one first electromagnetic sensing coil, located within said distal tip;   c) at least one second electromagnetic sensing coil in said proximal handle; said first electromagnetic sensing coil and said second electromagnetic sensing coil operating together to permit navigation through lung tissue and for reporting the location of said catheter distal tip in said lung tissue;   d) an ultrasound transducer array located within said distal tip for transmitting and receiving ultrasonic energy, said ultrasound transducer array operating in a first imaging mode to acquire an image of a first target area located in a first target plane and to define a second target area located in said first target plane comprising a reduced second target area smaller than said first target area;   e) said ultrasound transducer array operating in a second backscatter mode;   f) a module in communication with the ultrasound transducer array and configured to evaluate the spectral characteristics of acoustic energy reflected from said second target area forming a quantitative ultrasound data set; and   g) a navigation system/us display to present navigation, location and ultrasound data to said physician user.   
     
     
         2 . The medical device of  claim 1 , wherein the ultrasound transducer array comprises a plurality of transducer pairs, each transducer pair comprises a first transducer functioning as a transmitter and a second transducer functioning as a receiver. 
     
     
         3 . The medical device of  claim 2 , wherein a first transducer pair of the ultrasound transducer array operating at a first frequency in the first imaging mode and a second transducer pair of the ultrasound transducer array operating at a second frequency in the second imaging mode. 
     
     
         4 . The medical device of  claim 2 , wherein the plurality of transducer pairs are located along the length of the distal tip. 
     
     
         5 . The medical device of  claim 3 , wherein the first transducer pair and the second transducer pair operate at the same time. 
     
     
         6 . The medical device  claim 1 , wherein the reduced second target area is selected to be free of anatomic detail displayed in the first target plane. 
     
     
         7 . The medical device of  claim 2 , wherein a compensation profile is generated for each transducer in the ultrasound transducer array over the entire operating range of the transducer. 
     
     
         8 . The medical device of  claim 7 , wherein each compensation profile is stored in a computer readable memory located in the catheter. 
     
     
         9 . The medical device of  claim 2 , further comprising at least one independent transducer functioning as a sensor and located at a point along the length of the distal tip. 
     
     
         10 . The medical device of  claim 9  wherein the independent transducer is configured to receive ultrasonic energy produced in the first imaging mode and the second imaging mode. 
     
     
         11 . The medical device of  claim 10 , wherein the at least one independent transducer is a plurality of independent transducers, the plurality of independent transducers located along the length of the distal tip. 
     
     
         12 . The medical device of  claim 11 , wherein the plurality of independent transducers are operated at the same time. 
     
     
         13 . The medical device of  claim 10 , wherein the plurality of independent transducers are operated separately. 
     
     
         14 . A method of diagnosing a region of interest within lung tissue of a patient comprising the steps of:
 a) passing a catheter through a percutaneous needle to access said lung tissue, the catheter comprising:
 i) an elongate catheter body including a longitudinal axis and a distal tip and a proximal handle, 
 ii) at least two distal electromagnetic sensing coils located within said distal tip, 
 iii) at least one proximal electromagnetic sensing coil located in the proximal handle, and 
 iv) a multi-element ultrasound transducer array located within said distal tip, the ultrasound transducer array positioned parallel to the longitudinal axis of said catheter body; 
   b) navigating said distal tip of the catheter to a first location proximal to the region of interest using a navigation system that interacts with the distal and proximal electromagnetic sensing coils;   c) in a first imaging mode, transmitting from the ultrasound transducer array first ultrasound energy into the region of interest in a first target plane;   d) receiving the first ultrasound energy from the transducer array at an imaging system;   e) at the imaging system, creating an image of the region of interest along the first target plane, the image showing an anatomic structure, said anatomic structure selected from a set of structures comprising airways and blood vessels;   f) identifying a second target area within the first target plane comprising a reduced second target area smaller than said first target area;   g) in a second imaging mode transmitting second ultrasound energy from the transducer array into the reduced second target area;   h) receiving the second ultrasound energy from the transducer array at a backscatter evaluation system;   i) at the backscatter evaluation system, evaluating the acoustic spectra of the received second ultrasound energy to form a quantitative ultrasound data set.   
     
     
         15 . A medical system, comprising:
 a catheter terminating in a proximal handle and extending along an axis to a distal tip, the catheter adapted for delivery to lung tissue by insertion through a percutaneous needle;   an ultrasound transducer array located within said distal tip for transmitting and receiving ultrasonic energy, wherein the ultrasound transducer array comprises:
 a first transducer having first geometric properties corresponding to a first resonant frequency, and 
 a second transducer having second geometric properties corresponding to a second resonant frequency that is higher than the first resonant frequency; and 
   a module that is operably coupled to the ultrasound transducer array and configured to cause:
 the first transducer to operate at the first resonant frequency in an imaging mode for generating ultrasound images of a target tissue, and 
   
       the second transducer to operate at the second resonant frequency in a quantitative ultrasound mode for generating spectral parameters associated with the target tissue, wherein the spectral parameters are usable for characterizing the target tissue via an in situ acoustic biopsy.