Method and apparatus for placing and maintaining a percutaneous tube into a body cavity

Abstract

Innovative disposable thoracostomy and cricothyrotomy trocar systems and new and improved methods for emergency management of upper airway obstructions and chest injuries are disclosed.

I claim:  
     
         1 . A surgical cutting tool comprising a cam action retractable blade assembly having two blades, each with a blade edge and an angled blade point.  
     
     
         2 . The tool of  claim 1  wherein the blade assembly further comprises two substantially identical blades each having an edge face with a single bevel cutting edge disposed at an angle to a longitudinal axis of the blade, each edge ending in a blade point at a distal end of the blade, each blade further having a pin hole in a proximal region of the blade with a hole center lying on the blade axis, and each blade further having a cam slot distal to the pin hole with an distal cam slot center lying substantially on the blade axis and a proximal cam slot center lying substantially on a line between the pin hole center and the blade point; the two blades pivotally mounted edge face to edge face upon a pivot pin engaged within both pin holes; the tool further comprising a cam pin, the cam pin relatively stationarily engaged within both cam slots; wherein movement of the pivot pin in a distal direction urges the two blades to rotate their two blade points closer to each other and movement of the pivot pin in a proximal direction urges the two blades to rotate their two blade points further from each other.  
     
     
         3 . The tool of  claim 1  wherein the blade assembly further comprises two substantially identical blades each having an edge face with a single bevel cutting edge disposed at an angle to a longitudinal axis of the blade, each edge ending in a blade point at a distal end of the blade, the two blades pivotally mounted edge face to edge face upon a pivot pin, the blade points overlapped in an extended configuration.  
     
     
         4 . The tool of  claim 1  further comprising a safe zone at a tip of the extended configuration.  
     
     
         5 . The tool of  claim 1  further comprising a spring and a pushrod engaging the blades to extend the blade assembly against spring tension into a locked position when fully extended.  
     
     
         6 . The tool of  claim 5  wherein the pushrod is a wire, or other flexible push-pull linkage.  
     
     
         7 . A cannula for surgical procedures, the cannula comprising a collapsible retention lattice at a distal end.  
     
     
         8 . The cannula of  claim 7  wherein the lattice is further comprised of struts, and the struts are formed in a partial frusto-conical configuration at the distal end of the cannula.  
     
     
         9 . The cannula of  claim 7  wherein, prior to assembly, the lattice structure is formed substantially flat, and the cannula is segmented, cannula segments depending radially from the flat formed lattice.  
     
     
         10 . The cannula of  claim 7  wherein the cannula and lattice structure further comprise four contiguous rectilinear zones defined by an intersecting pair of substantially perpendicular lines, a central portion of each of which is open or latticed.  
     
     
         11 . A retractable trocar comprising a cam action retractable blade assembly having two blades, each with a blade edge and an angled blade point.  
     
     
         12 . The trocar of  claim 11  wherein the blade assembly further comprises two substantially identical blades each having an edge face with a single bevel cutting edge disposed at an angle to a longitudinal axis of the blade, each edge ending in a blade point at a distal end of the blade, the two blades pivotally mounted edge face to edge face upon a pivot pin, the blade points overlapped in an extended configuration.  
     
     
         13 . The trocar of  claim 12  further comprising a safe zone at a tip of the extended configuration.  
     
     
         14 . The trocar of  claim 11  further comprising a handle enclosing at least a portion of a spring and a pushrod engaging the blades to extend the blade assembly against spring tension into a locked position when fully extended, and a releasable lock mechanism.  
     
     
         15 . The trocar of  claim 11  further comprising an additional tapered zone proximal to a distal end of a trocar shaft.  
     
     
         16 . The trocar of  claim 11  further comprising an expandable cannula folded and engaged upon a trocar shaft.  
     
     
         17 . The trocar of  claim 11  further comprising a self deploying, removable, one way exit valve foldably engaged upon a hub end of the cannula.  
     
     
         18 . The trocar of  claim 16  wherein the cannula comprises a multi-segmental flexible piece, the segments joined in the center by a geometrically regular network of filaments, the filaments shaped and conjoined in such a way as to enable the segments to be folded and interengaged into a substantially tubular shape with the filaments thereby forming an outwardly collapsible structure having at least two break lines.