Transesophageal ultrasound probe with an adaptive bending section

Abstract

When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter.

What is claimed is: 
     
         1 . An ultrasound probe, comprising:
 a shaft;   a distal section with an ultrasound transducer housed therein;   a bending section disposed between the shaft and the distal section, the bending section having a proximal portion and a distal portion, wherein the distal portion is flexible and the proximal portion is more flexible than the distal portion, and wherein the bending section comprises a plurality of axially-arranged vertebrae; and   a bending mechanism configured to bend the bending section when actuated,   wherein the bending section is configured such that when a part of the bending section is distal to a constraint that prevents bending and the bending mechanism is actuated, a proximal section of the part articulates before more distal sections of the part articulate.   
     
     
         2 . The probe of  claim 1 , wherein the flexibility of the bending section decreases gradually in the proximal to distal direction. 
     
     
         3 . The probe of  claim 1 , wherein the flexibility of the bending section decreases in a stepwise manner in the proximal to distal direction. 
     
     
         4 . The probe of  claim 1 , wherein the bending section contains a middle portion disposed between the proximal portion and the distal portion, and wherein the proximal portion is more flexible than the middle portion and the middle portion is more flexible than the distal portion. 
     
     
         5 . The probe of  claim 1 , wherein the bending mechanism comprises at least one pull wire configured to cause the bending section to move in either a first radial direction or a second radial direction that is opposite to the first radial direction. 
     
     
         6 . A probe, comprising:
 a shaft;   a distal section having a sensor;   a bending section disposed between the shaft and the distal section, the bending section having a proximal portion and a distal portion, wherein the distal portion is flexible and the proximal portion is more flexible than the distal portion, and wherein the bending section comprises a plurality of axially-arranged vertebrae; and   a bending mechanism configured to bend the bending section when actuated,   wherein the bending section is configured such that when a part of the bending section is distal to a constraint that prevents bending and the bending mechanism is actuated, a proximal section of the part articulates before more distal sections of the part articulate.   
     
     
         7 . The probe of  claim 6 , wherein the sensor comprises at least one of an optical sensor, a thermal sensor, an imaging device, and a pressure sensor. 
     
     
         8 . The probe of  claim 7 , wherein the bending mechanism comprises at least one pull wire configured to cause the bending section to move in either a first radial direction or a second radial direction that is opposite to the first radial direction. 
     
     
         9 . The probe of  claim 6 , wherein the flexibility of the bending section decreases gradually in the proximal to distal direction. 
     
     
         10 . The probe of  claim 6 , wherein the flexibility of the bending section decreases in a stepwise manner in the proximal to distal direction. 
     
     
         11 . The probe of  claim 6 , wherein the bending section contains a middle portion disposed between the proximal portion and the distal portion, and wherein the proximal portion is more flexible than the middle portion and the middle portion is more flexible than the distal portion. 
     
     
         12 . The probe of  claim 11 , wherein the sensor comprises at least one of an optical sensor, a thermal sensor, an imaging device, and a pressure sensor. 
     
     
         13 . The probe of  claim 12 , wherein the bending mechanism comprises at least one pull wire. 
     
     
         14 . An ultrasound probe, comprising:
 a shaft having a distal end;   a distal section having a proximal end and an ultrasound transducer; and   a bending section with a flexible proximal portion engaging the shaft distal end and a flexible distal portion engaging the distal section proximal end, wherein the proximal portion is configured to permit bending in a given direction and has a first flexibility for bending in the given direction and the distal portion is configured to permit bending in the given direction and has a second flexibility for bending in the given direction, the first flexibility being more flexible than the second flexibility, wherein the bending section is configured such that when a part of the bending section is distal to a constraint, a proximal section of the part articulates before more distal sections of the part articulate, and wherein the bending section comprises a plurality of axially-arranged vertebrae.   
     
     
         15 . The probe of  claim 14 , further comprising a bending mechanism configured to bend the bending section. 
     
     
         16 . The probe of  claim 15 , wherein the bending section comprises at least one pull wire configured to cause the bending section to move in either a first radial direction or a second radial direction that is opposite to the first radial direction. 
     
     
         17 . The probe of  claim 14 , further comprising a flexible central portion configured to permit bending in the given direction and disposed between the proximal and distal portions of the bending section, the central portion having a third flexibility for bending in the given direction different than the first and second flexibilities. 
     
     
         18 . The probe of  claim 17 , the first flexibility being more flexible than the third flexibility, and the third flexibility being more flexible than the second flexibility. 
     
     
         19 . The probe of  claim 17 , the third flexibility being a gradient flexibility between the first and second flexibilities. 
     
     
         20 . The probe of  claim 17 , the third flexibility having a variable flexibility between the first and second flexibilities. 
     
     
         21 . The probe of  claim 17 , the third flexibility having a graduated flexibility between the first and second flexibilities. 
     
     
         22 . The probe of  claim 14 , the bending section having a tubular jacket disposed around a longitudinal axis of the bending section, the tubular jacket having a wall with a thickness varying along a longitudinal length of the jacket, the wall thickness defining a graduated flexibility of the bending section. 
     
     
         23 . The probe of  claim 22 , the jacket have a plurality of wall thicknesses along the longitudinal length of the jacket. 
     
     
         24 . The probe of  claim 23 , further comprising a bending mechanism configured to bend the bending section. 
     
     
         25 . The probe of  claim 23 , the jacket wall including one or more outer walls disposed around the jacket wall. 
     
     
         26 . The probe of  claim 14 , the proximal portion being made from a first material with a first flexibility property, the distal portion made from a second material with a second flexibility property different than the first flexibility property. 
     
     
         27 . The probe of  claim 26 , further comprising a flexible central portion configured to permit bending in the given direction and disposed between the proximal and distal portions of the bending section, the central portion made from a third material with a third flexibility property different than the first and second flexibility properties. 
     
     
         28 . The probe of  claim 27 , the first flexibility property being more flexible than the third flexibility property, and the third flexibility property being more flexible than the second flexibility property. 
     
     
         29 . The probe of  claim 27 , the third flexibility property providing a gradient flexibility of the central portion. 
     
     
         30 . The probe of  claim 27 , the third flexibility property providing a variable flexibility of the central portion. 
     
     
         31 . The probe of  claim 14 , the bending portion including a plurality of grooves disposed along an outer surface of the bending portion. 
     
     
         32 . The probe of  claim 31 , wherein the plurality of grooves is longitudinally disposed on the outer surface of the bending portion, at least one groove having a depth differing from another groove. 
     
     
         33 . The probe of  claim 31 , the plurality of grooves helically disposed on the outer surface.