Flexible multi-arm catheter with diametrically opposed sensing electrodes

A manufacturing method, comprising:

• producing multiple flexible spines having multiple electrodes disposed thereon, the multiple electrodes comprising multiples pairs of first and second electrodes;
• 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 the distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the multiple flexible spines are bent proximally such that the second ends are more proximal than the first ends, and wherein each of the multiple flexible spines comprises a tensile layer configured to cause the flexible spine to bend proximally;
• wherein producing the multiple flexible spines comprises disposing the multiple electrodes on circuit board substrates, each circuit board substrate comprising a folding line;
• and
• wherein producing the multiple flexible spines comprises folding the circuit board substrates along the folding line so that, for each respective pair of first and second electrodes, the first and second electrode are (i) disposed over diametrically opposing facets of the respective circuit board substrate, (ii) separated electrically along the folding line, and (iii) electrically connected to one another by a via extending through the respective circuit board substrate.

A manufacturing method, comprising:

• patterning electrodes and conductive lines on multiple flexible circuit boards, the electrodes comprising pairs of first and second electrodes;
• folding the flexible circuit boards along respective folding lines of the circuit boards, over one or more fibers made of a tensile material, such that the one or more fibers become sandwiched between two diametrically opposing facets of the patterned flexible boards, so as to form multiple flexible spines, and such that, for each respective pair of first and second electrodes, the first electrode and the second electrode are (i) disposed over diametrically opposing facets of respective the circuit board substrate, (ii) separated electrically along the folding lines, and (iii) electrically connected to one another by a via extending through the respective circuit board substrate;
• 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 the distal end of the shaft and respective second ends that are free-standing and unanchored, wherein the multiple flexible 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 multiple flexible spines is configured to cause the multiple flexible spines to bend proximally.

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 from the distal end, each flexible spine comprising a folded flexible circuit board that includes:
• a respective first end that is connected to the distal end of the catheter shaft, a respective second end that is free-standing and unanchored, and a folding line the folded flexible circuit board is folded along;
• a first plurality of electrodes disposed on a surface of each of the multiple flexible spines, the first plurality of electrodes facing the longitudinal axis;
• and
• a second plurality of electrodes disposed on a surface of each of the multiple flexible spines, the second plurality of electrodes facing away from the longitudinal axis, the second plurality of electrodes being separated electrically from the first plurality of electrodes along the folding line, and each electrode of the second plurality of electrodes being electrically connected to a respective electrode of the first plurality of electrodes by a via extending through the respective folded flexible circuit board;
• and
• a tensile member disposed between the folded flexible circuit board having tensile strength greater than 895 MPa.