Safety penetrating instrument with expandible portion and method of penetrating anatomical cavity

A safety penetrating instrument for penetrating an anatomical wall or body lumen, comprising

• a portal sleeve having proximal and distal ends,
• an elongated penetrating member axially movable in said portal sleeve and having a distal end and a proximal end, the distal end of said elongated penetrating member comprising a tip including a sharp element for piercing the anatomical wall,
• an outermost covering adhering over said sharp element, said covering comprising a material having a first state with a first hardness and a second state with a second hardness less than the first hardness, and
• means connected to said elongated penetrating member for causing said covering material to transition from said first hardness state to said second hardness state,
• whereby, when the distal end of the elongated penetrating member passes from a position outside the anatomical wall to a position inside the anatomical wall, at least a portion of said covering transitions from the first state to the second state to form a protective member for said sharp element of the tip.

A safety penetrating instrument for penetrating a wall of an anatomical cavity or lumen, comprising:

• an elongated penetrating member having a distal end and a proximal end, the distal end having a leading end section and being sized and adapted for entering into the wall of the anatomical cavity or lumen;
• and
• an expandible member comprising an outermost covering over a sharp tip of the leading end section and fabricated from an expandible material having a dry, compacted, hard state before entering into the wall of the anatomical cavity or lumen and a wet, soft, expanded state after entering into the wall of the anatomical cavity or lumen,
• whereby, when the distal end passes from a position outside the anatomical cavity or lumen to a position inside the anatomical cavity or lumen, at least a portion of the expandible member adjacent the distal end is hydrated causing the expandible member to expand from the dry, hard, compacted state to the wet, soft, expanded state forming a protective barrier over at least the leading end section of the distal end.