Flexible tip medical instrument

A biopsy device having a flexible distal portion for obtaining a biopsy sample from a biopsy site, comprising:

• a coring cannula having a cannula wall between a proximal end and a distal end and defining a lumen therebetween, said wall defining a coring relief notch adjacent said distal end, said coring relief notch having a length along a longitudinal axis of said coring relief notch sized to define a wall portion of said cannula wall that is more flexible than the remainder of said cannula wall;
• a wire slidably disposable within said lumen of said coring cannula and having a proximal end and a distal end, said wire defining a sampling cavity adjacent said distal end and a wire relief notch adjacent said sampling cavity, said wire relief notch having a length along a longitudinal axis of said wire sized to define a portion of said wire that is more flexible than the remainder of said wire;
• said wire and said coring cannula having a first position with said wire retracted within said lumen so that said coring cannula covers said sampling cavity and a second position wherein said distal end of said wire is extended away from said coring cannula to expose said cavity;
• and
• a firing mechanism engaged to said proximal ends of said coring cannula and said wire, said firing mechanism operable to move said coring cannula relative to said wire from the second position to the first position to trap tissue from the biopsy site in the sampling cavity,
• wherein said firing mechanism engaged to said proximal ends of said coring cannula and said wire orient said coring cannula relative to said wire so that said flexible wall portion of said cannula opposes said flexible portion of said wire.

An assembly for engagement to a firing mechanism of a biopsy device for obtaining a biopsy sample from a biopsy site, comprising:

• a coring cannula having a cannula wall between a proximal end engageable to the firing mechanism and a distal end, and defining a lumen therebetween, said cannula wall defining a coring relief notch adjacent said distal end, said coring relief notch having a length along a longitudinal axis of said coring relief notch sized to define a wall portion of said cannula wall that is more flexible than the remainder of said cannula wall;
• and
• a wire slidably disposable within said lumen of said coring cannula and having a proximal end engageable to the firing mechanism and a distal end, said wire defining a sampling cavity adjacent said distal end and a wire relief notch adjacent said sampling cavity, said wire relief notch having a length along a longitudinal axis of said wire sized to define portion of said wire that is more flexible than the remainder of said wire;
• said wire and said coring cannula configured so that in a first position with said wire and said coring cannula engaged to the firing mechanism, said coring cannula covers said sampling cavity, and said coring relief notch overlaps said wire relief notch.

An assembly for engagement to a firing mechanism of a for obtaining a biopsy sample from a biopsy site, comprising:

• a coring cannula having a cannula wall between a proximal end engageable to the firing mechanism and a distal end, and defining a lumen therebetween, said cannula wall defining a coring relief notch adjacent said distal end, said coring relief notch having a length along a longitudinal axis of said coring relief notch sized to define a wall portion of said cannula wall that is more flexible than the remainder of said cannula wall;
• and
• a wire slidably disposable within said lumen of said coring cannula and having a proximal end engageable to the firing mechanism and a distal end, said wire defining a sampling cavity adjacent said distal end and a wire relief notch adjacent said sampling cavity, said wire relief notch having a length along a longitudinal axis of said wire sized to define portion of said wire that is more flexible than the remainder of said wire;
• said wire and said coring cannula configured so that in a first position with said wire and said coring cannula engaged to the firing mechanism, said coring cannula covers said sampling cavity, and said coring relief notch overlaps said wire relief notch,
• wherein said firing mechanism engaged to said proximal ends of said coring cannula and said wire orient said coring cannula relative to said wire so that said flexible wall portion of said cannula opposes said flexible portion of said wire.