Focusing catheter

A coaxial stream delivery device comprising:

• an inlet section comprising:
• (i) an inner tubular wall extending along a longitudinal axis to define an inner lumen;
• (ii) an outer tubular wall extending along the longitudinal axis concentrically about the inner tubular wall;
• and
• (iii) N bridges extending radially between the inner tubular wall and the outer tubular wall to define N corresponding annular sector apertures, where the N is at least one;
• a source of cells coupled to an upstream end of the inner lumen;
• and
• a plenum chamber defined within a plenum wall that extends distally along the longitudinal axis from a distal end of the inlet section, the plenum chamber in fluid communication with the inner lumen and the N corresponding annular sector apertures,
• wherein:
• the N annular sector apertures provide longitudinal fluid communication between a first supply conduit coupled to a proximal end of the inlet section and the plenum chamber,
• an inner radius of the plenum wall monotonically decreases distally along the longitudinal axis,
• an inner radius of the outer tubular wall and an outer radius of the inner tubular wall are substantially constant along the longitudinal axis,
• the inlet section is configured to receive a sheath fluid stream through the N corresponding annular sector apertures and to receive through the inner lumen a therapeutic fluid stream comprising cells from the source of cells, such that,
• the sheath fluid stream shields the therapeutic fluid stream such that deleterious shear stress to the cells is prevented;
• and
• further comprising a downstream sheath reduction apparatus configured such that a volume of the sheath fluid stream is removed from the therapeutic fluid stream via at least one exit port prior to delivery of the therapeutic fluid stream.