Active fixation electrode lead having an electrical coupling mechanism

An implantable endocardial lead extending between proximal and distal ends for use with a cardiac stimulation device comprising:

• an electrical conductor within the lead extending between proximal and distal ends;
• an insulation sheath covering the conductor;
• an electrical connector coupled to the proximal end of the conductor;
• an active fixation electrode coupled to the distal end of the conductor and movable between a retracted position and an extended position advanced beyond the distal end of the lead for effecting penetration into the myocardial tissue;
• an electrically active housing at the distal end of the lead;
• a resilient coupling mechanism for maintaining electrical continuity between the active fixation electrode and the electrically active housing throughout movement of the active fixation electrode between the retracted position and the extended position;
• a conductive shaft having a longitudinal axis that is generally coaxial with the electrical conductor, the conductive shaft having an outer surface and extending between proximal and distal ends, the electrical conductor being fixed to the proximal end thereof;
• and
• an annular collar integral with the conductive shaft intermediate the proximal and distal ends and projecting radially from the longitudinal axis to an outer rim beyond the outer surface of the conductive shaft;
• and
• wherein the resilient coupling mechanism includes:
• a tubular conductive coupling fixed to the electrically active housing and coaxial with and slidably received on the conductive shaft and having an internal peripheral surface facing and spaced from a part of the conductive shaft and having a distal terminal surface;
• a conductive stopper integral with the conductive shaft including a ring member projecting radially from the longitudinal axis to a peripheral rim beyond the outer surface of the conductive shaft;
• and
• a compression spring intermediate and engaged with the conductive coupling and with the conductive stopper;
• the annular collar being engaged with the distal terminal surface of the conductive coupling when the active fixation electrode is in the retracted position and being spaced from the distal terminal surface of the conductive coupling when the active fixation electrode is in the extended position.

An implantable endocardial lead extending between proximal and distal ends for use with a cardiac stimulation device comprising:

• an electrical conductor within the lead extending between proximal and distal ends;
• an insulation sheath covering the conductor;
• an electrical connector coupled to the proximal end of the conductor;
• an active fixation electrode coupled to the distal end of the conductor and movable between a retracted position and an extended position advanced beyond the distal end of the lead for effecting penetration into the myocardial tissue;
• an electrically active housing at the distal end of the lead;
• a resilient coupling mechanism for maintaining electrical continuity between the active fixation electrode and the electrically active housing throughout movement of the active fixation electrode between the retracted position and the extended position;
• and
• a conductive shaft having a longitudinal axis that is generally coaxial with the electrical conductor, the conductive shaft having an outer surface and extending between proximal and distal ends, the electrical conductor being fixed to the proximal end thereof;
• and
• wherein the resilient coupling mechanism includes:
• an annular track member integral and in electrical continuity with the electrically active housing and having an annular recess surrounding the conductive shaft;
• and
• a metallic coil spring received in the annular recess and slidably engageable with the conductive shaft.

An implantable endocardial lead extending between proximal and distal ends for use with a cardiac stimulation device comprising:

• an electrical conductor within the lead extending between proximal and distal ends;
• an insulation sheath covering the conductor;
• an electrical connector coupled to the proximal end of the conductor;
• an active fixation electrode coupled to the distal end of the conductor and movable between a retracted position and an extended position advanced beyond the distal end of the lead for effecting penetration into the myocardial tissue;
• an electrically active housing at the distal end of the lead;
• a resilient coupling mechanism for maintaining electrical continuity between the active fixation electrode and the electrically active housing throughout movement of the active fixation electrode between the retracted position and the extended position;
• a conductive shaft having a longitudinal axis that is generally coaxial with the electrical conductor, the conductive shaft having an outer surface and extending between proximal and distal ends, the electrical conductor being fixed to the proximal end thereof;
• and
• an annular collar integral with the conductive shaft intermediate the proximal and distal ends and projecting radially from the longitudinal axis to an outer rim beyond the outer surface of the conductive shaft;
• and
• wherein the resilient coupling mechanism includes:
• a tubular conductive coupling fixed to the electrically active housing and coaxial with the conductive shaft and having an internal peripheral surface facing and spaced from a part of the conductive shaft and having a distal terminal surface;
• an annular track member fixed to the tubular conductive coupling and having an annular recess surrounding the conductive shaft;
• and
• a metallic coil spring received in the annular recess and slidably engageable with the conductive shaft;
• the annular collar being engaged with the distal terminal surface of the conductive coupling when the active fixation electrode is in the retracted position and being spaced from the distal terminal surface of the conductive coupling when the active fixation electrode is in the extended position.