Multi-electrode implantable systems and assemblies thereof

A connector terminal for an implantable medical electrical lead, the connector terminal comprising:

• a first electrical contact member and a second electrical contact member, the second contact member being electrically isolated from the first contact member and spaced apart, distally from the first contact member along a length of the connector terminal, and the second contact member having a proximal end and a distal end;
• and
• a switching assembly comprising a multiplexer, a proximal feedthrough subassembly and a distal feedthrough subassembly, the multiplexer being mounted on an integrated circuit chip within the second connector contact member and electrically coupled to the second contact member, the proximal feedthrough subassembly including a conductive ferrule attached to the proximal end of the second contact member, a feedthrough pin and an insulator isolating the pin from the ferrule and being hermetically sealed to the pin and to the ferrule, the feedthrough pin electrically coupling the first contact member to the multiplexer, and the distal feedthrough subassembly including a conductive ferrule attached to the distal end of the second contact member, a plurality of feedthrough pins and an insulator isolating each of the pins from one another and from the ferrule of the distal subassembly, and being hermetically sealed to each of the pins and to the ferrule of the distal subassembly, each feedthrough pin of the distal subassembly being electrically coupled to the multiplexer and having a distal portion that extends distally from the distal end of the second contact member, the distal portions being positioned with respect to one another in order to allow for electrical coupling with a plurality of elongate conductors of the lead;
• wherein the multiplexer includes a switch matrix element and a communications, control and power supply element, the switch matrix element including a plurality of pairs of switches, each pair of the plurality of pairs of switches corresponding to one of the feedthrough pins of the distal feedthrough assembly, a first of each pair of switches being adapted to connect and disconnect the corresponding feedthrough pin to/from the first contact member and the communications, control and power supply element, and a second of each pair of switches adapted to connect and disconnect the corresponding feedthrough pin to/from the second contact member and the communications, control and power supply element;
• and
• each ferrule of the proximal and distal feedthrough assemblies is attached to the corresponding end of the proximal and distal ends of the second contact member by a weld that extends about an entire perimeter of the corresponding end.