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

Abstract

A safety penetrating instrument for penetrating an anatomical wall or a body lumen comprises an elongated penetrating member having proximal and distal ends. The distal end of the elongated penetrating member has a sharp or blunt tip for piercing the anatomical wall or penetrating the body lumen. A covering for the tip comprises an expandible sponge material having a first state with a first hardness and a second state with a second hardness less than the first hardness. Hydrating the covering material causes it to transition from the first hardness state to the second hardness state so that when the distal end of the elongated penetrating member passes from a position outside the anatomical wall or body lumen to a position inside the anatomical wall or lumen, the covering transitions from the first state to the second state to form a relatively soft protective member for the sharp or blunt tip. A method of safety penetration comprises the steps of covering the tip with an expandible sponge material and hydrating the covering during penetration of the anatomical wall or body lumen. The safety penetrating instrument may comprise a trocar with a portal sleeve, a cannula, needle, catheter or the like and may be provided with devices for optical viewing, imaging and/or sensing parameters, such as pressure, temperature, pH and other chemistry.