Coupling units for medical device delivery systems

A stent delivery system, comprising:

• a core member having a distal segment;
• a coupling unit positioned about the core member distal segment, the coupling unit comprising:
• a proximal restraint coupled to the core member distal segment;
• a distal restraint coupled to the core member distal segment at a position distal to the proximal restraint;
• two or more plates slidably coupled to the core member distal segment between the proximal restraint and the distal restraint;
• and
• one or more spacers coupled to the core member distal segment between the proximal restraint and the distal restraint,
• wherein the proximal restraint and the distal restraint are spaced apart along the core member by a longitudinal distance that is greater than the combined length of the two or more plates and the one or more spacers coupled to the core member distal segment between the proximal restraint and the distal restraint;
• and
• a stent extending along the core member distal segment such that an inner surface of the stent is engaged by at least one of the plates.

A stent delivery system, comprising:

• a catheter having a lumen and an inner surface extending along the lumen;
• a core member, extending within the catheter lumen;
• first and second couplers slidably mounted to the core member, each of the first and second couplers comprising:
• a first end surface, a second end surface, and a side surface extending between the first end surface and the second end surface;
• and
• an aperture extending through the first and second end surfaces, the core member and extending through the aperture, the aperture defining a radial gap between an outer surface of the core member and an inner surface of the coupler;
• one or more spacers mounted on the core member;
• a proximal restraint mounted on the core member at a position proximal to the first coupler, the second coupler, and the one or more spacers;
• a distal restraint mounted the core member at a position distal to the first coupler, the second coupler, and the one or more spacers, the distal restraint spaced apart from the proximal restraint by a longitudinal distance greater than the combined length of the first and second couplers and the one or more spacers;
• and
• a stent extending along the core member and disposed radially between the catheter inner surface and the first and second couplers.

An assembly configured to engage a stent, comprising:

• a core member;
• a proximal restraint mounted on the core member;
• a distal restraint mounted on the core member at a position distal the proximal restraint;
• a first coupler slidably coupled to the core member between the proximal restraint and the distal restraint;
• a second coupler slidably coupled to the core member at a position between the proximal restraint and the distal restraint;
• and
• one or more spacers coupled to the core member at a position between the proximal restraint and the distal restraint,
• wherein the proximal and distal restraints are spaced apart along the core member by a longitudinal distance that is greater than a combined length of the first and second couplers and the one or more spacers.