Fiber optic imaging catheter

Abstract

A steerable imaging catheter is provided, including an elongated catheter tube, at least one steering cable extending along the catheter tube to control the movement of the distal end thereof, and a fiber optic cable extending along the catheter tube. The fiber optic cable transmits illumination light from its proximal end to its distal end and transmits an image from its distal end to its proximal end. In one embodiment, two or more steering cables are used, and the catheter tube is configured to have greater flexibility near its distal end than its proximal end so as to concentrate the movement (flexing) of the catheter tube at its distal end. The use of two or more steering cables, together with the catheter tube having varying flexibility, permit better control of the distal end of the catheter tube while reducing undue twisting of the remainder of the catheter tube.

1 - 22 . (canceled) 
     
     
         23 . A catheter, comprising:
 an elongated catheter tube having a proximal end and a distal end;   at least one elongate element extending along the catheter tube substantially from the proximal end to the distal end of the catheter tube to control movement of the distal end of the catheter tube;   an optical element having a proximal end and a distal end, the optical element extending along the catheter tube substantially from the proximal end to the distal end of the catheter tube, the optical element being configured to transmit light to a tissue positioned near the distal end of the optical element and to receive light reflected from the tissue; and   a processor connected to a proximal end of the optical element and configured to determine a state of the tissue based on a wavelength of the transmitted light and a wavelength of the received light.   
     
     
         24 . The catheter of  claim 23 , wherein the state of the tissue is one of healthy or unhealthy. 
     
     
         25 . The catheter of  claim 24 , wherein unhealthy tissue includes at least one of cancerous tissue and necrotic tissue. 
     
     
         26 . The catheter of  claim 23 , wherein the processor is configured to determine a difference between the wavelength of the transmitted light and the wavelength of the received light. 
     
     
         27 . The catheter of  claim 26 , wherein the processor is configured to determine the state of the tissue based on a previous difference determined corresponding to a known healthy tissue. 
     
     
         28 . The catheter of  claim 23 , wherein the optical element is also configured to transmit illumination from the proximal end of the optical element to the distal end of the optical element while transmitting an image from the distal end of the optical element to the proximal end of the optical element. 
     
     
         29 . A method of diagnosing a tissue, comprising:
 advancing a catheter to a position in a body of a patient, the catheter having an elongated catheter tube, and the elongated catheter tube having at least one elongate element extending along the elongated catheter tube to control movement of a distal end of the elongated catheter tube, the elongated catheter tube further having an optical element extending along the elongated catheter tube,   transmitting light from the optical element to a tissue within the body of the patient;   receiving reflected light from the tissue via the optical element; and   determining, using a processor connected to a proximal end of the optical element, a state of the tissue based on a wavelength of the transmitted light and a wavelength of the received light.   
     
     
         30 . The method of  claim 29 , wherein the state of the tissue determined is one of healthy or unhealthy. 
     
     
         31 . The method of  claim 30 , wherein unhealthy tissue includes at least one of cancerous tissue and necrotic tissue. 
     
     
         32 . The method of  claim 29 , wherein the determining step includes determining a difference between the wavelength of the transmitted light and the wavelength of the received light. 
     
     
         33 . The method of  claim 29 , further comprising transmitting light to a known healthy tissue, receiving reflected light from the known healthy tissue, and determining a state of the known healthy tissue prior to transmitting light to the tissue. 
     
     
         34 . The method of  claim 33 , wherein determining the state of the tissue is based on the determination of the state of the known health tissue. 
     
     
         35 . The method of  claim 29 , further comprising transmitting illumination from the proximal end of the optical element to the distal end of the optical element while transmitting an image from the distal end of the optical element to the proximal end of the optical element. 
     
     
         36 . The method of  claim 30 , further comprising a step of removing the unhealthy tissue. 
     
     
         37 . The method of  claim 36 , wherein the step of removing the unhealthy tissue includes delivering radio frequency energy to the unhealthy tissue via a first one of the at least one elongate elements. 
     
     
         38 . The method of  claim 37 , wherein a portion of the first one of the at least one elongate elements extends distally of a distal end of the elongated catheter tube. 
     
     
         39 . A method for cutting tissue or other material from a body of a patient, comprising:
 advancing a catheter to a position in a body of a patient, the catheter having an elongated catheter tube, the elongated catheter tube having at least one elongate element extending along the elongated catheter tube to control movement of a distal end of the elongated catheter tube, the elongated catheter tube further having an optical element extending along the elongated catheter tube, a first one of the at least one elongate elements being configured to transmit radio frequency energy, and   delivering radio frequency energy from the first one of the at least one elongate elements to cut the tissue or other material.   
     
     
         40 . The method of  claim 39 , wherein a portion of the first one of the at least one elongate elements extends distally of a distal end of the elongated catheter tube. 
     
     
         41 . The method of  claim 40 , further comprising simultaneously viewing the portion of the first one of the at least one elongate elements using the optical element while delivering the radio frequency energy from the first one of the at least one elongate elements. 
     
     
         42 . The method of  claim 39 , wherein the tissue to be cut is the sphincter.