| 摘要 |
<p>A selectively aspirating stylet assembly comprises a stylet having proximal and distal ends, the proximal end in fluid communication with a fluid supply and the distal end disposed at or near the end of a catheter, cannula or other generally tubular member that is to be inserted to a specified location within a patient's body, so as to create a fluid flow path from the fluid supply through the generally tubular member to the specified location. A valve assembly located within the fluid flow path is operable to close off a fluid column within the stylet assembly to facilitate placement of the tubular member within the body, and to control the flow of fluids within the assembly. Insertion of the tubular member into the body is accomplished by placing a portion of the stylet within the tubular member; closing the valve assembly to create a closed fluid column; inserting the stylet/tubular member assembly into the body; and then, during the withdrawal of the stylet, opening or closing the valve assembly as necessary to control the flow of fluid within the stylet/tubular member assembly to avoid substantial aspiration of body fluid and tissue.</p> |
