Medical balloon with enhanced refolding properties

A medical balloon comprising:

• a first end member disposed at a distal end of a longitudinal axis;
• a second end member spaced apart from the first end member and disposed at a proximal end of the longitudinal axis;
• and
• a generally cylindrical balloon wall extending between the end members to define an inflation chamber which is adapted for inflation from a first folded configuration having a first plurality of pleats to an expanded, unpleated configuration and deflation from the expanded, unpleated configuration to a second folded configuration having a second plurality of pleats, the balloon wall including a first layer;
• wherein the first layer is formed of a polymer and has, when viewed in cross section along the longitudinal axis, a substantially constant radial thickness around the circumference;
• a second layer firmly attached to the first layer, the second layer having, when viewed in cross section along the longitudinal axis, a plurality of first regions of greater radial thickness interleaved with a plurality of second regions of reduced radial thickness, the second layer being made from a single layer of polymer material that fully encompasses the first layer when viewed in cross section along the longitudinal axis;
• and
• at least one elongated reinforcing fiber member;
• whereby, during deflation from the expanded, unpleated configuration to the second folded configuration, the balloon wall folds along each of the second regions of reduced radial thickness of the second layer to form each pleat of the second plurality of pleats such that each pleat of the second plurality of pleats includes a fold along a second region of reduced radial thickness at a radially outer tip of the pleat and such that each adjacent pair of pleats of the second plurality of pleats includes a fold along a second region of reduced radial thickness at a position between the adjacent pair of pleats.

A medical balloon comprising:

• a first end member disposed at a distal end of a longitudinal axis;
• a second end member spaced apart from the first end member and disposed at a proximal end of the longitudinal axis;
• and
• a generally cylindrical balloon wall extending between the end members to define an inflation chamber which is adapted for inflation from a first folded configuration having a first plurality of pleats to an expanded, unpleated configuration and deflation from the expanded, unpleated configuration to a second folded configuration having a second plurality of pleats, the balloon wall including a first layer;
• wherein the first layer is formed of a polymer and has, when viewed in cross section along the longitudinal axis, a substantially constant radial thickness around the circumference;
• a second layer firmly attached to the first layer, the second layer having, when viewed in cross section along the longitudinal axis, a plurality of first regions of relatively greater longitudinal stiffness interleaved with a plurality of second regions of relatively reduced longitudinal stiffness, the second layer being made from a single layer of polymer material that fully encompasses the first layer when viewed in cross section along the longitudinal axis;
• and
• a plurality of elongated reinforcing fiber members;
• whereby, during deflation from the expanded, unpleated configuration to the second folded configuration, the balloon wall folds along each of the second regions of reduced longitudinal stiffness of the second layer to form each pleat of the second plurality of pleats such that each pleat of the second plurality of pleats includes a fold along a second region of reduced longitudinal stiffness at a radially outer tip of the pleat and such that each adjacent pair of pleats of the second plurality of pleats includes a fold along a second region of reduced longitudinal stiffness at a position between the adjacent pair of pleats.