Flexible Multi-Arm Catheter with Diametrically Opposed Sensing Electrodes

Abstract

A medical instrument includes a shaft, multiple flexible spines and multiple electrodes. The shaft is configured for insertion into a body of a patient. The multiple flexible spines have respective first ends that are connected to a distal end of the shaft and respective second ends that are free-standing and unanchored. The spines are bent proximally such that the second ends are more proximal than the first ends. Each of the flexible spines includes a tensile layer configured to cause the flexible spine to bend proximally. The multiple electrodes are disposed over the flexible spines.

1 . A medical instrument, comprising:
 a shaft for insertion into a body of a patient;   multiple flexible spines, having respective first ends that are connected to a distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the spines are bent proximally such that the second ends are more proximal than the first ends, and wherein each of the flexible spines comprises a tensile layer configured to cause the flexible spine to bend proximally; and   multiple electrodes disposed over the flexible spines.   
     
     
         2 . The medical instrument according to  claim 1 , wherein the multiple electrodes are disposed over diametrically opposing surfaces of the flexible spines. 
     
     
         3 . The medical instrument according to  claim 1 , wherein the flexible spines and the electrodes comprise circuit board substrates, and metallic elements disposed on the circuit board substrates, respectively. 
     
     
         4 . The medical instrument according to  claim 3 , wherein the circuit board substrates are folded so that the multiple electrodes are disposed over diametrically opposing facets of the circuit board substrates. 
     
     
         5 . The medical instrument according to  claim 1 , wherein each of the tensile layers comprises one or more tensile fibers configured to cause the flexible spine to bend proximally. 
     
     
         6 . The medical instrument according to  claim 1 , wherein a tensile strength of the tensile layer is greater than that of a Nitinol alloy layer of same dimensions. 
     
     
         7 . A manufacturing method, comprising:
 producing multiple flexible spines having multiple electrodes disposed thereon; and   mounting the multiple flexible spines at a distal end of a shaft, wherein the multiple flexible spines have respective first ends that are connected to a distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the spines are bent proximally such that the second ends are more proximal than the first ends, and wherein each of the flexible spines comprises a tensile layer configured to cause the flexible spine to bend proximally.   
     
     
         8 . The manufacturing method according to  claim 7 , wherein producing the spines comprises disposing multiple electrodes over diametrically opposing surfaces of the flexible spines. 
     
     
         9 . The manufacturing method according to  claim 7 , wherein producing the spines comprises disposing the electrodes on circuit board substrates. 
     
     
         10 . The manufacturing method according to  claim 9 , wherein producing the spines comprises folding the circuit board substrates so that the multiple electrodes are disposed over diametrically opposing facets of the circuit board substrates. 
     
     
         11 . The manufacturing method according to  claim 7 , wherein producing the spines comprises fitting one or more tensile fibers in each of the spines, so as to cause the flexible spine to bend proximally. 
     
     
         12 . The manufacturing method according to  claim 7 , wherein producing the spines comprises including a tensile layer with tensile strength that is greater than that of a Nitinol alloy layer of same dimensions. 
     
     
         13 . A manufacturing method, comprising:
 patterning electrodes and conductive lines on multiple flexible circuit boards;   laminating pairs of the flexible circuit boards, with a layer of tensile material sandwiched between the circuit boards of each pair, so as to form flexible spines; and   mounting the multiple flexible spines at a distal end of a shaft, wherein the multiple flexible spines have respective first ends that are connected to a distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the spines are bent proximally such that the second ends are more proximal than the first ends, and wherein a tensile layer included in each of the flexible spines is configured to cause the flexible spines to bend proximally.   
     
     
         14 . A manufacturing method, comprising:
 patterning electrodes and conductive lines on multiple flexible circuit boards; and   folding the flexible circuit boards along respective longitudinal axes of the circuit boards, over one or more fibers made of a tensile material, such that the fibers become sandwiched between two diametrically opposing facets of the patterned flexible boards, so as to form flexible spines; and   mounting the multiple flexible spines at a distal end of a shaft, wherein the multiple flexible spines have respective first ends that are connected to a distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the spines are bent proximally such that the second ends are more proximal than the first ends, and wherein a tensile layer included in each of the flexible spines is configured to cause the flexible spines to bend proximally.   
     
     
         15 . A medical instrument, comprising:
 a catheter shaft extending along a longitudinal axis from a proximal end to a distal end;   multiple flexible spines extending out of the catheter shaft toward the distal end, each flexible spine includes:   a respective first end that is connected to the distal end of the catheter shaft and respective second end that is free-standing and unanchored;   a first plurality of electrodes disposed on a surface of the spine facing the longitudinal axis; and   a second plurality of electrodes disposed on a surface of the spine facing away from the longitudinal axis; and   a tensile member disposed between the first and second plurality of electrodes having tensile strength greater than 895 MPa.