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US 4,787,751 AGranted
Bone cement mixing device
OwnerMarinus Bakelsinventor
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OwnerMarinus Bakelsinventor
Estimating the term…
A bone cement mixing device has a holding chamber mounted in a housing for vibration with its top extending through the top of said housing. A nitrogen operated vibrator vibrates said holding chamber and the interior of said chamber is connected to a vacuum source. A gun cartridge is placed in said holding chamber to receive bone cement ingredients to be vibrated and placed under a vacuum to deaerate the combined ingredients.
A device for mixing bone cement comprising a housing plate means, a cylinder means being open at the top and having a closed bottom, said cylinder means defining a cylindrical holding chamber, mounting means for mounting said cylinder means on said housing plate means to permit vibration of said cylinder means thereon, vibration means fixedly connected to the side of said cylinder means for vibrating said cylinder means, means for turning said vibration means on and off, a removable cartridge for mixing bone cement being positioned in said cylindrical holding chamber of said cylinder means for vibration therewith, means for spacing said removable cartridge from the wall of said cylindrical holding chamber forming a space therebetween, said removable cartridge being cylindrical and shorter than said cylindrical holding chamber, said removable cartridge being open at its upper end to receive elements of a bone cement for mixing together, a vacuum source, means for turning said vacuum source on and off, conduit means for connecting said vacuum source to said holding chamber through the wall of said cylinder means below the open upper end of said removable cartridge, said conduit means drawing gases from the cylindrical holding chamber from below the open upper end of said removable cartridge through said space when said vacuum source is on.
A device for mixing bone cement comprising a housing plate means, one cylinder means being open at the top and having a closed bottom, said cylinder means defining a single cylindrical holding chamber, a mounting plate means for said one cylinder means, means fixing the bottom of said one cylinder means to said mounting plate means, vibration mounts connected between said mounting plate means and said housing plate means to support said mounting plate means with said one cylinder means and permit vibration of said one cylinder means, vibration means fixedly connected to the side of said one cylinder means between its top and bottom for vibrating said cylinder means, means for turning said vibration means on and off, a removable cartridge for mixing bone cement being positioned in said cylindrical holding chamber of said cylinder means for vibration therewith, means for spacing said removable cartridge from the wall of said cylindrical holding chamber forming a space therebetween, said removable cartridge being cylindrical and shorter than said cylindrical holding chamber, said removable cartridge being open at its upper end to receive liquid and powder elements of a bone cement for mixing while said cylinder means is open, said vibration means being used to vibrate said cylinder means and said removable cartridge while said liquid and powder elements of a bone cement are being mixed, a vacuum source, means for turning said vacuum source on and off, conduit means for connecting said vacuum source to said holding chamber through the wall of said cylinder means below the open upper end of said removable cartridge, said conduit means drawing gases from the cylindrical holding chamber from below the open upper end of said removable cartridge through said space when said vacuum source is on, a cover for placement over the open end of the cylinder means when a vacuum is desired therein, said vibration means being used to vibrate said removable cartridge when under a vacuum to deaerate said mixed bone cement.
A device for use in an operating room to prepare bone cement in a removable cartridge, a housing plate means, a cylindrical holding device being open at the top and closed at the bottom, said cylindrical holding device having a cylindrical holding chamber, mounting means for mounting said cylindrical holding device to said housing plate means to permit vibration of said cylindrical holding device, a cylindrical cartridge for preparing a bone cement for use, said cartridge being positioned in said cylindrical holding chamber and having an open upper end for receiving the elements of a bone cement for mixing, vibration means connected to the side of said cylindrical holding device for vibrating said device and said cartridge, means for turning said vibration means on and off, means for spacing said cartridge from the wall of said cylindrical holding chamber to permit gas flow therebetween when said bone cement elements are being placed in said cartridge and mixed, said cartridge being cylindrical and shorter than said holding chamber, a vacuum source, means for turning said vacuum source on and off, conduit means for connecting said vacuum source to said holding chamber through said cylindrical holding device below the open top of said cartridge and open top of said cylindrical holding device, said conduit means drawing gases formed by the mixing of the bone cement elements from the cylindrical holding chamber to prevent them from entering an operating room.
Dependencies are inferred from the claim text.
Other mixers; Mixing plants; Combinations of mixers: mixers specially adapted for working at sub- or super-atmospheric pressure, e.g. combined…
For introducing fluid filler into bone or extracting it: with filtering, degassing, venting or pressure relief means
Mixing by means of high-frequency vibrations above one kHz, e.g. ultrasonic vibrations: with vibration of the receptacle or part of it
Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use: portable during use, e.g. hand-held
Term ended 20 Jun 2006 (estimated)
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This invention relates to the preparation of bone cement to reduce porosity and improve the fatigue strength of the bone cement, and provide a simplified method of applying the bone cement.
Bone cement has been prepared generally by mixing the required components, attempting to deaerate the bone cement, and placing it in a bone cement gun for delivery to a desired operating area. Various mixing procedures have been used, including hand-mixing in a bowl with a fume evacuator; and a cement cartridge with the mixed bone cement placed therein has been located in a centrifuge to attempt to reduce porosity. The majority of bone cement guns used are similar and can be used with applicant's apparatus.
An object of the present invention is to provide a device which will permit the mixing of the bone cement in a cement gun cartridge positioned in a housing, and deaerate the bone cement in the gun cartridge without removing it from the housing.
FIG. 1 is a perspective view of the bone cement mixing device for the preparation of bone cement showing nitrogen and vacuum controls and connections;
FIG. 2 is a left side view of the bone cement mixing device omitting the housing cover and the vacuum circuit, and showing the bone cement holding chamber and a portion of the mounting means in section;
FIG. 3 is a right side view of the bone cement mixing device omitting the nitrogen circuit and showing the housing cover and bone cement holding chamber in section;
The apparatus 2 for preparing bone cement includes a housing 4 and has five (5) main elements therein: (1) a bone cement gun cartridge holding chamber 6; (2) mounting means 8 for mounting said holding chamber 6 for vibration on a bottom plate 16 of housing 4; (3) a fluid operated vibration means 10 fixed to holding chamber 6 for vibrating it; (4) driving fluid conduit means 12 for connecting a driving fluid to said vibration means 10; and (5) conduit means 14 for applying a vacuum to the interior of said holding chamber 6.
The bottom plate 16 of housing 4 includes an upwardly extending control panel 18 and a rubber foot 19 at each corner. A cover 20 is positioned over, and fixed to, said bottom plate 16 by screws 22, with a cut-out portion 24 fitting around said upwardly extending control panel 18. The top of the cover 20 has an opening 26 therein for the top of the cartridge holding chamber 6 to extend therethrough. Cover 20 is also provided with holes 21 on each side thereof to provide for sterilization of the apparatus 2, such as in an autoclave.
The bone cement gun cartridge holding chamber 6 is formed as a cylinder 30 being open at the top and having a closed bottom 32. A cylindrical extension 34 is fixed to the top of the cylinder 30 to provide a larger opening for entry into the holding chamber 6. The upper end of the cylindrical extension 34, which extends through an opening 26 in the top of the cover 20, is adapted to receive a cover 38. Cover 38 can be attached to the top of the cover 20 by attaching means such as a wire, cord, or hinge means. Four rubber snubbers 40 are equally spaced around the interior of the opening 26 and extend radially inwardly of the opening 26 toward the cylindrical extension 34 of the holding chamber 6 to prevent the cylindrical extension 34 from contacting the top of the cover 20 when it is vibrating (to be hereinafter described). Each snubber 40 comprises a small angle member 42 with one arm fixed to the inner surface of the top of the cover 20, and the other arm extending downwardly. A solid rubber member 44 is fixed to each downwardly extending arm of each small angle member 42. Each solid rubber member 44 is formed around a metal core having a threaded member 46 extending externally of the rubber member 44. Each threaded member 46 is threadably mounted to the downwardly extending arm of the small angle member 42.