Microminiature EM Coil Sensor Pull Ring For Catheter

A method of manufacturing a microminiature electro-magnetic coil sensor pull ring for use in a medical catheter, comprising:

• forming a tubular pull ring, the tubular pull ring having a full wall thickness about a longitudinal axis;
• machining a coil wrap area by removing material from an outer side of the full wall thickness;
• machining an electrical connection recess into the full wall thickness and located proximal to the coil wrap area;
• machining at least one pull wire connection location into the full wall thickness and located proximal to the coil wrap area;
• winding a coil about the coil wrap area, the coil being formed of a flexible, electrically insulated metal wire with a plurality of turns for sensing through human tissue, the wire being smaller than 40 AWG, the wire terminating in two lead ends extending flexibly from the turns;
• attaching at least one pull wire to the pull ring within the pull wire connection location, the pull wire being adapted for changing the angle of the pull ring for navigation of the medical catheter through human tissue;
• and
• electrically connecting circuit wires to the two lead ends within the connection recess, such that neither the circuit wires nor the lead ends stand proud of the full wall thickness.