Patents by Inventor Kazuhiko Sawai

Kazuhiko Sawai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5728395
    Abstract: A hydroxylapatite base porous beads filler for use in cure of an injured or diseased part of bone of an organism. The porous filler is comprised of fired hydroxylapatite base beads each of which is formed with many pores. Each pore of the bead has a diameter of 1 to 100 .mu.m and a length larger than the diameter. Each bead has a porosity of 10 to 50% and a diameter of 0.02 to 20 mm. The pores of the bead may be filled with a solution containing a pharmaceutical in order to promote the cure of the injured or diseased part.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: March 17, 1998
    Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Takayuri Kato, Shinpei Hashimoto, Kazuhiko Sawai, Tomokazu Hattori, Shigeo Niwa
  • Patent number: 5665120
    Abstract: A biomedical material in use for curing the bone defect or the like in human being or an animal. The biomedical material is comprised of a flexible fiber-meshed micro-tube which has an outer diameter ranging from 50 .mu.m to 10 mm and is formed of a net or a cloth woven from fibers. The fibers are biodegradable and capable of maintaining their shape within a time period ranging from 1 week to 30 weeks in the body. Additionally, hydroxylapatite beads and/or flakes are filled in the fiber-meshed micro-tube. The biomedical material is located in the bone defect or the like under an operation, in which blood can effectively circulate through the mesh of the micro-tube and through the spaces among the hydroxylapatite beads and/or flakes, thereby promoting the cure of the bone defect or the like.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: September 9, 1997
    Assignee: Tohkai Ceramic Material Co., Ltd.
    Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Shigeo Niwa, Kazuhiko Sawai, Hajime Ohta
  • Patent number: 5266248
    Abstract: A method of producing a hydroxylapatite base porous beads filler for an organism, including mixing hydroxylapatite powder having particle sizes not larger than 125 .mu.m, in an amount ranging from 40 to 90% by weight, synthetic resin powder having particle sizes not larger than 74 .mu.m, in an amount ranging from 5 to 55% by weight, and resinous binder in an amount ranging from 0.5 to 5% by weight to obtain a mixture, granulating the mixture to form beads each having a diameter ranging from 0.03 to 25 mm, firing the beads at a temperature ranging from 900.degree. C. to 1180.degree. C. to form hydroxylapatite base porous beads, dipping the porous beads in a colloidal solution, removing air from the porous beads under vacuum, and filling the colloidal solution into the pores in the porous beads under pressure.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: November 30, 1993
    Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Takayuri Kato, Shinpei Hashimoto, Kazuhiko Sawai, Tomokazu Hattori, Shigeo Niwa
  • Patent number: 4994085
    Abstract: An artificial stem unit for coxa with a setting guide comprises a stem made of metal to be inserted into the marrow cavity of a femur and a setting guide for fixing the stem in the marrow cavity comprising a cylindrical core rod and a plug attached to the end of the cylindrical core rod. In the operation, the setting guide is inserted into the marrow cavity of the femur in advance for the centering, and thereafter, the stem is inserted so that the through hole of the stem fit with the cylindrical core rod of the setting guide. Then the bone cement is injected to fix the stem at an accurate position set up by the above operation.
    Type: Grant
    Filed: March 8, 1989
    Date of Patent: February 19, 1991
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Kazuhiko Sawai, Shigeo Niwa, Tomokazu Hattori, Wataru Yagi, Ryohei Yabuno, Masami Ishii
  • Patent number: 4979958
    Abstract: An artificial stem for femur of coxa in a human body comprises a stem element, a head and a neck connecting the both, each side surface of the stem element corresponding to the indise or outside of a human body being formed by a specific curved or straight line respectively, the cross section of the stem element having a specific shape, and scale-like step patterns being formed on both the front and back surfaces, thereby improving the fitness to the femur of a small body person like Japanese, the stability and the anti-twisting strength after insertion.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: December 25, 1990
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Shigeo Niwa, Kazuhiko Sawai, Tomokazu Hattori, Yasumasa Matsuda, Wataru Yagi, Masami Ishii, Junichi Mita, Masuo Yamada
  • Patent number: 4497075
    Abstract: A filler for filling in defects or hollow portions of bones to coalesce with the bone tissues is provided which comprises powders of a calcium phosphate compound having the apatite crystalline structure of each crystallite size of 400 .ANG. or larger and of each crystal grain size of 3 .mu.m or smaller, said calcium phosphate compound being represented by the following general formula of Ca.sub.m (PO.sub.4).sub.n OH (1.33.ltoreq.m/n.ltoreq.1.95), and said powders being fluidized or plasticized.
    Type: Grant
    Filed: March 1, 1982
    Date of Patent: February 5, 1985
    Assignee: Mitsubishi Mining & Cement Co., Ltd.
    Inventors: Shigeo Niwa, Kazuhiko Sawai, Shinobu Takahashi, Mikiya Ono, Yoshiaki Fukuda, Hiroyasu Takeuchi, Hideo Tagai
  • Patent number: 4429691
    Abstract: A filler for filling in defects or hollow portions of bones to coalesce with the bone tissues is provided which comprises powders of a calcium phosphate compound having the apatite crystalline structure of each crystal grain size of from 50 .orgate. to 10 microns and represented by the following general formula of Ca.sub.m (PO.sub.4).sub.n OH (1.33.ltoreq.m/n.ltoreq.1.95); and said powders being adapted for filling in a fluidized or plasticized state. A method of treating a bone with the filler is also provided wherein at least a portion of said filler is filled in to reach the bone-marrow cavity of said bone.
    Type: Grant
    Filed: January 25, 1982
    Date of Patent: February 7, 1984
    Assignee: Mitsubishi Mining and Cement Company, Ltd.
    Inventors: Shigeo Niwa, Kazuhiko Sawai, Shinobu Takahashi, Hideo Tagai, Mikiya Ono, Yoshiaki Fukuda, Hiroyasu Takeuchi