Provided herein are a system and method for detaching a therapeutic device, e.g. an embolic coil, from a delivery tube at a target site in a patients body. The system includes a bead disposed against a distal end of the therapeutic device that retains the therapeutic device to the delivery tube in a first compressed configuration through a coupling union comprising a series of connectors. The series of connectors may include a stretch resistant member through which the bead is attached to an anchor inside the therapeutic device. The anchor, in turn, may be disposed against a thermally responsive element comprised of a polymeric material configured to melt or otherwise change configuration to release the anchor, and with it, to also release the therapeutic device. Energy may be supplied to the thermally responsive element through electrical conductors and a resistive heating element disposed within the delivery tube.