Patent ID: 8475485

Claim:
A medical instrument having a cannula, a seal disposed in said cannula, said seal has an opening for guiding a shaft of another instrument through said seal and said cannula in a sealed manner, an expansion device for expanding said opening in said seal for guiding said shaft of said other instrument of greater diameter in a sealed manner through said expanded opening said expansion device having an expansion cone comprising a plurality of slats mounted pivotably on an annular body at a first end thereof, a second end of said slats, opposite to said first end, being connected to said seal in an area of said opening, said slats forming said expansion cone narrowing from a proximal to a distal end thereof, wherein said slats are connected at its first ends via film hinges to said annular body, wherein said seal extends in a distal direction away from a distal end of said expansion cone, and wherein said seal is designed as a pot-seal, a bottom of said pot-seal is connected to said distal end of said expansion cone.