Devices and processes for delivery of therapeutic fluids

A therapeutic agent delivery system, comprising:

• an elongated housing having a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal end portion and the distal end portion;
• a therapeutic agent delivery assembly carried by the housing, the therapeutic agent delivery assembly comprising:
• a chamber comprising a passageway configured to carry a therapeutic agent;
• a needle in communication with the passageway;
• the therapeutic agent delivery assembly being translatable relative to the housing along the longitudinal axis from a stowed configuration to a deployed configuration, in the deployed configuration the needle at least partially extending distally from the distal end portion of the housing, and the therapeutic agent delivery assembly being translatable relative to the housing from the deployed configuration to a retracted configuration, in the retracted configuration the needle being disposed proximally relative to the distal end portion of the housing;
• a user input at the proximal end portion configured to be actuated by a user, actuation of the user input translating the therapeutic agent delivery assembly from the stowed configuration to the deployed configuration;
• and
• a retraction mechanism comprising:
• a retraction base;
• a retraction cap carried by the retraction base and being rotatable relative to the retraction base;
• a biasing element carried between the retraction base and the retraction cap and being reconfigurable from a higher energy storage configuration to a lower energy storage configuration to translate the retraction cap, the chamber, and the needle together relative to the retraction base;
• an electronics assembly configured to generate a retraction signal;
• and
• a wire coupled to at least one of the retraction base and the retraction cap and being actuatable by the electronics assembly in response to the retraction signal to permit the biasing element to reconfigure from the higher energy storage configuration to the lower energy storage configuration, the biasing element thereby translating the therapeutic agent delivery assembly from the deployed configuration to the retracted configuration, wherein the wire comprises a shape memory material configured to contract upon receiving thermal energy from the electronics assembly, wherein contracting the wire rotates the retraction cap relative to the retraction base to disengage coupling features of the retraction cap and the retraction base.