Veress needle and cannula assembly

A medical apparatus, comprising:

• a) a cannula assembly having
• i) a hollow cannula with a proximal end, a distal end, and an interior diameter,
• ii) a valve assembly coupled to said proximal end of said cannula;
• and
• b) a Veress needle assembly fitting closely within said hollow cannula and having
• i) an outer hollow needle having a proximal end, a sharp distal end, and an exterior diameter which is smaller than said interior diameter of said hollow cannula, wherein said valve assembly permits insertion of said outer hollow needle into said cannula and fluidly seals the proximal end of said cannula,
• ii) an inner stylet having a proximal end and a blunt distal end, said inner stylet extending through said outer hollow Veress needle;
• iii) a handle coupled to said proximal end of said outer hollow needle, said handle having biasing means for biasing said stylet to a position where said blunt distal end of said stylet extends beyond said sharp distal end of said outer hollow needle;
• and
• iv) a transition collar mounted on a portion of said outer hollow needle, said transition collar having an inner diameter substantially equal to said exterior diameter of said outer hollow needle and an outer diameter substantially equal to said interior diameter of said hollow cannula to cause said Veress needle assembly to fit closely within said cannula.