Biostimulator transport system having swaged torque shaft

A biostimulator transport system, comprising:

• a handle;
• a docking cap having a docking cavity to receive an attachment feature of a biostimulator;
• and
• a torque shaft having a proximal shaft end coupled to the handle and a distal shaft end coupled to the docking cap, wherein the torque shaft includes an inner coil including a wire coil extending about a central axis along an inner helical axis in a first helical direction, and an outer cable including a plurality of outer strands extending helically around the inner coil along respective outer helical axes in a second helical direction, wherein the outer helical axes are orthogonal to the inner helical axis, wherein the torque shaft includes welds between the outer cable and the inner coil at the proximal shaft end and the distal shaft end, wherein the outer cable is swaged onto the inner coil over a plurality of swaged sections between the welds at the proximal shaft end and the distal shaft end such that an outer surface of the outer cable is flattened and the wire coil bulges into circumferential gaps between the plurality of outer strands to form an annular wall around a central lumen, and wherein stiffnesses of the plurality of swaged sections decrease in a distal direction between the welds at the proximal coil end and the distal coil end.

A method of manufacturing a torque shaft assembly, comprising:

• loading an outer cable over an inner coil to form a torque shaft having a proximal shaft end and a distal shaft end, wherein the inner coil includes a wire coil extending about a central axis along an inner helical axis in a first helical direction, wherein the outer cable includes a plurality of outer strands extending helically around the inner coil along respective outer helical axes in a second helical direction, and wherein the outer helical axes are orthogonal to the inner helical axis;
• welding the outer cable to the inner coil at the proximal shaft end and the distal shaft end;
• and
• swaging the outer cable onto the inner coil over a plurality of swaged sections between the welds at the proximal shaft end and the distal shaft end such that an outer surface of the outer cable is flattened and the wire coil bulges into circumferential gaps between the plurality of outer strands to form an annular wall around a central lumen, and wherein stiffnesses of the plurality of swaged sections decrease in a distal direction between the welds at the proximal coil end and the distal coil end.

A torque shaft assembly, comprising:

• an inner coil including a wire coil extending about a central axis along an inner helical axis in a first helical direction over a coil length between a proximal coil end and a distal coil end;
• an outer cable including a plurality of outer strands extending helically around the inner coil in a second helical direction along respective outer helical axes from the proximal coil end to the distal coil end, wherein the torque shaft assembly includes welds between the outer cable and the inner coil at the proximal coil end and the distal coil end, wherein the outer cable is swaged onto the inner coil over a plurality of swaged sections between the welds at the proximal coil end and the distal coil end such that an outer surface of the outer cable is flattened and the wire coil bulges into circumferential gaps between the plurality of outer strands to form an annular wall around a central lumen, and wherein stiffnesses of the plurality of swaged sections decrease in a distal direction between the proximal coil end and the distal coil end;
• and
• an outer sleeve containing the inner coil and the outer cable.