Clutch for disposable pump cartridge

A method comprising:

• inserting a rotor into an inner ring, which is disposed within an outer ring and is shaped to define multiple compartments having respective outer openings, which face the outer ring, and respective inner openings opposite the outer openings,
• the outer ring including an inner surface shaped to define multiple recesses, and being coupled with a shaft coupled with a motor,
• multiple gripping elements being disposed within the compartments, respectively, and
• the compartments being aligned with the recesses, by virtue of the gripping elements sitting at least partially within the recesses;
• and
• activating the motor to rotate the shaft, thereby causing the compartments to become misaligned with the recesses such that the outer ring pushes the gripping elements, through the outer openings, against the rotor, through the inner openings, such that the rotor rotates with the shaft
• wherein the outer ring is shaped to define an outer radial aperture,
• wherein the inner ring is shaped to define an inner radial aperture aligned with the outer radial aperture, and
• wherein a compressible peg, which passes through the outer radial aperture and the inner radial aperture:
• becomes and remain compressed during the rotation of the outer ring, and
• decompresses following the rotation of the shaft, thereby realigning the compartments with the recesses.