Bone cement mixer and method
OwnerWilliam M. Murrayinventor
Life of this patent
Estimating the term…
Abstract
A bone cement mixer having a cartridge housing for receiving an open bone cement cartridge filled with bone cement powder with a stirrer in the cartridge, and a cover which is fitted over the housing to define a vacuum chamber. The chamber is evacuated and monomer liquid is flowed into the bone cement powder in the cartridge in a stream that penetrates the bone cement powder and distributes monomer liquid essentially uniformly along the height of the bone cement powder. The powder and liquid are then mechanically mixed to form bone cement.
Claims54
A device for mixing a bone cement liquid with a bone cement powder to form liquid bone cement, the device comprising:
- a body having walls surrounding a closed body interior;
- a vacuum port in a body wall;
- a mixing chamber in the body;
- a cement liquid chamber in a body wall;
- a nozzle located in a body wall above the mixing chamber and in flow communication with the cement liquid chamber, said nozzle aimed at the mixing chamber and having a small flow passage;
- and
- a cement stirring drive, the stirring drive including an operator on the outside of the body and a driven element on the inside of the body adjacent the mixing chamber.
A device for mixing bone cement liquid with bone cement powder to form liquid bone cement, the device comprising:
- a body;
- a mixing chamber in the body;
- a cement liquid chamber in the body;
- and
- a nozzle at the bottom of the liquid chamber, said nozzle aimed at the mixing chamber, said nozzle having a cross small cross sectional area for flowing a penetrating stream of bone cement liquid into the mixing chamber.
A method of mixing liquid bone cement from dry bone cement powder and bone cement liquid using a mixer of the type having a closed cement mixing chamber, comprising the steps of:
- (a) providing a column of dry bone cement powder in the mixing chamber, the column having a top and a bottom;
- (b) evacuating the mixing chamber to remove air from the bone cement powder;
- (c) providing a volume of bone cement liquid appropriate for mixing with the bone cement powder to form mixed liquid bone cement of a desired viscosity;
- (d) flowing the volume of bone cement liquid down into the top of the column of bone cement powder in a narrow high speed stream having a fixed orientation without forming a puddle at the top of the column;
- (e) moving the stream from the top of the column down to the bottom of the column, absorbing bone cement liquid from the stream into bone cement powder in the column to form a body of liquid-rich bone cement powder adjacent the stream extending from the top of the column to the bottom of the column while maintaining the bone cement powder in the column away from the body dry;
- and
- (f) stirring the body of liquid-rich bone cement powder and the dry bone cement powder to form a liquid bone cement having the desired viscosity.
A method of mixing liquid bone cement from dry bone cement powder and bone cement liquid comprising the steps of:
- (a) providing a vertical column of dry bone cement powder in a mixing chamber;
- (b) flowing a narrow high speed stream of bone cement liquid having a fixed orientation vertically down into and through the column of bone cement powder;
- (c) absorbing bone cement liquid from the stream into dry bone cement powder in the column adjacent the stream to form a body of wetted bone cement powder extending from the top of the column to the bottom of the column;
- (d) mixing the wetted bone cement powder with the dry bone cement powder in the chamber to form liquid bone cement having a substantially uniform viscosity.
Dependencies are inferred from the claim text.