Electrode lead set for measuring physiologic information

An electrode lead set is provided for electrical connection to a body. The electrode lead set includes a flexible substrate core extending between a proximal end portion and a distal end portion. The distal end portion includes a plurality of branch end portions that are each configured to hold an electrode. The substrate core is separable into a plurality of branches that are each joined to adjacent branches by a separable interface prior to separation. Each of the plurality of branches includes a corresponding one of the branch end portions. Prior to separation, the plurality of branches are configured such that the branch end portions are maintained in an array at the distal end portion of the substrate core. An electrically conductive pathway extends along each branch from the corresponding branch end portion toward the proximal end portion of the substrate core.