Apparatus for extracting bone marrow specimens

Claim 1

A device for extracting marrow from a bone, comprising: a tubular guide having an inner and outer end, external threads on said guide adjacent said inner end, said guide having a cutting edge on its inner end adapted to cut through the skin and to penetrate the bone surface and to aid in holding the guide in place in the bone, a guide depth guard having internal threads engaged with said external threads adjacent said inner end, said guide being adapted to indicate and limit the desired length of insertion of the guide to penetrate the bone, said depth guard being rotatable on said guide toward and away from said inner end and having means close to the skin to be gripped for insertion of the guide into the skin and bone, said depth guard being adapted to abut the skin and prevent additional penetration of the guide when the guide has been inserted to the selected depth, a hollow needle having a conical inner end having a cutting edge and an outer end engaged with rotation means for rotation thereby, said conical inner end having an axially directed opening in said inner end within said cutting edge to receive and retain marrow therein, said needle being slidably fitted within said guide with its inner end adjacent the inner end of said guide when said guide has penetrated the bone, said needle having its outer end extending outwardly of the outer end of the guide, said needle having external threads adjacent the outer end of the guide, portions of said threads being adapted to be positioned to extend simultaneously into the guide and outwardly of the guide, and a measuring guard threadedly engaged on said threads on said needle outwardly of said guide to limit inward movement of the needle in said guide and into the marrow of the bone, said threads on said needle being of substantial length to permit substantial longitudinal adjustment of the measuring guard on the needle to substantially vary the limit of said inward movement, said measuring guard limiting the inward movement by abutting the outer end of the guide.

Claim 2

A device for extracting marrow from a bone, comprising: a tubular guide having an inner and outer end, external threads on said guide adjacent said inner end, said guide having a cutting edge on its inner end adapted to cut through the skin and to penetrate the bone surface and to aid in holding the guide in place in the bone, a guide depth guard having internal threads engaged with said external threads adjacent said inner end, said guide being adapted to indicate and limit the desired length of insertion of the guide to penetrate the bone, said depth guard being rotatable on said guide toward and away from said inner end and having means close to the skin to be gripped for insertion of the guide into the skin and bone, said depth guard being adapted to abut the skin and prevent additional penetration of the guide when the guide has been inserted to the selected depth, a hollow needle having a conical inner end having a cutting edge and an outer end engaged with rotation means for rotation thereby, said conical inner end having an axially directed opening in said inner end within said cutting edge to receive and retain marrow therein, said needle being slidably fitted within said guide with its inner end adjacent the inner end of said guide when said guide has penetrated the bone, said needle having its outer end extending outwardly of the outer end of the guide, said needle having external threads adjacent the outer end of the guide, portions of said threads being adapted to be positioned to extend simultaneously into the guide and outwardly of the guide, and a measuring guard threadedly engaged on said threads on said needle outwardly of said guide to limit inward movement of the needle in said guide and into the marrow of the bone, said threads on said needle being of substantial length to permit substantial longitudinal adjustment of the measuring guard on the needle to substantially vary the limit of said inward movement, said measuring guard limiting the inward movement by abutting the outer end of the guide.