Patents by Inventor Shigeo Niwa
Shigeo Niwa 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).
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Patent number: 5728395Abstract: 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: GrantFiled: September 28, 1995Date of Patent: March 17, 1998Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Takayuri Kato, Shinpei Hashimoto, Kazuhiko Sawai, Tomokazu Hattori, Shigeo Niwa
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Patent number: 5665120Abstract: 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: GrantFiled: March 15, 1996Date of Patent: September 9, 1997Assignee: Tohkai Ceramic Material Co., Ltd.Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Shigeo Niwa, Kazuhiko Sawai, Hajime Ohta
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Patent number: 5266248Abstract: 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: GrantFiled: October 13, 1992Date of Patent: November 30, 1993Inventors: Torao Ohtsuka, Makoto Fukaya, Hideo Tagai, Takayuri Kato, Shinpei Hashimoto, Kazuhiko Sawai, Tomokazu Hattori, Shigeo Niwa
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Patent number: 5213112Abstract: A tension meter for measuring the degree of tension between bones has a grip portion, a tension meter body mounted to the grip portion, and a torque setting device rotatably connected through a torque shaft to the tension meter body. The tension meter body includes a body portion, a fixed arm extending from one end of the body portion, and a movable arm mounted on the body portion so as to be movable away therefrom. The movable arm is located in opposed relationship to the fixed arm. The movable arm is provided with a gear portion meshing the torque shaft. The torque setting device is provided with a torque limiter for limiting relative displacement of the movable arm in relation to the fixed arm according to a force to be applied between the fixed arm and the movable arm. Use of the tension meter produces quantitative data which makes it possible to carry out surgical operations with reproducible results because they do not rely only upon the surgeon's senses.Type: GrantFiled: January 29, 1992Date of Patent: May 25, 1993Assignee: Pfizer Hospital Products Group, Inc.Inventors: Shigeo Niwa, Mineo Sakakibara
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Patent number: 5013323Abstract: An implant material for replacing hard tissue of a living body is provided. The implant material comprises 10 to 90 wt % of a fiber glass and 90 to 10 wt % of an organic high polymer material. The fiber glass is mainly composed of calcium phosphate. The organic high polymer material does not inhibit affinity with the living body. On the surface of the implant material, a portion of the fiber glass is exposed.Type: GrantFiled: August 13, 1987Date of Patent: May 7, 1991Assignee: Mitsubishi Mining & Cement Co., Ltd.Inventors: Masahiro Kobayashi, Hideo Tagai, Yoshikatsu Kuroki, Shigeo Niwa, Mikiya Ono
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Patent number: 5007932Abstract: An artificial joint has a first member mounted on a first bone and a second member mounted on a second member. An angle defined between the first and second members is variable. The first member has a convex curved surface and the second member has a concave curved surface with is in sliding contact with the convex curved surface. A groove is formed in one of the first and second members and a boss inserted into the groove for limiting the sliding movement of the joint in a single plane is formed in the other of the members. Also, an artificial fixed knuckle bone is disclosed.Type: GrantFiled: February 27, 1989Date of Patent: April 16, 1991Assignee: NGK Spark Plug Co., Ltd.Inventors: Katsutoshi Bekki, Kazuo Kondo, Yoshimasa Shibata, Shigeo Niwa
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Patent number: 4994085Abstract: 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: GrantFiled: March 8, 1989Date of Patent: February 19, 1991Assignee: Aisin Seiki Kabushiki KaishaInventors: Kazuhiko Sawai, Shigeo Niwa, Tomokazu Hattori, Wataru Yagi, Ryohei Yabuno, Masami Ishii
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Patent number: 4979958Abstract: 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: GrantFiled: September 26, 1989Date of Patent: December 25, 1990Assignee: Aisin Seiki Kabushiki KaishaInventors: Shigeo Niwa, Kazuhiko Sawai, Tomokazu Hattori, Yasumasa Matsuda, Wataru Yagi, Masami Ishii, Junichi Mita, Masuo Yamada
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Patent number: 4944758Abstract: An artificial joint comprising a first member including a butt portion located at one end of the first member and having an internal opening and a long guide groove extending to the opening and a second member in contact with the butt portion of the first member and including an expanded portion at one end of the second member. The expanded portion is fitted in the internal opening of the first member. A projection along both sides of the long guide groove prevents the expanded portion from separating from the internal opening except at prescribed positions of the first and second members. The long guide groove guides the movement of the second member as it bends relative to the first member in a prescribed direction.Type: GrantFiled: September 16, 1988Date of Patent: July 31, 1990Assignee: NGK Spark Plug Co., Ltd.Inventors: Katsutoshi Bekki, Shigeo Niwa
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Patent number: 4910473Abstract: A digitally temperature-compensated oscillator has an oscillator for producing a frequency signal, a regulator for regulating the frequency of the frequency signal, and a detector for detecting ambient temperature and producing a corresponding temperature signal. A processor processes the temperature signal with reference to the frequency signal to produce processed temperature data. A memory stores compensation data effective to regulate the frequency of the frequency signal. A controller operates according to the temperature data to retrieve corresponding compensation data from the memory for controlling the regulator according to the retrieved compensation data to regulate the frequency of the frequency signal.Type: GrantFiled: July 1, 1988Date of Patent: March 20, 1990Assignee: Seiko Electronic Components Ltd.Inventor: Shigeo Niwa
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Patent number: 4820573Abstract: A fiber glass is provided for filling in a defect or hollow portion of bone. The fiber glass comprises calcium phosphate as a main ingredient and has a negative zeta potential. The calcium phosphate has a molar ratio of Ca/P of not less than 0.2 and less than 0.6 and the total content of CaO plus P.sub.2 O.sub.5 in the fiber glass is less than 80 wt %. The fiber glass is of long filament form or staple fiber form. The fiber glass of long filament form may be woven to form a woven filler.Type: GrantFiled: August 28, 1987Date of Patent: April 11, 1989Assignee: Mitsubishi Mining and Cement Co., Ltd.Inventors: Hideo Tagai, Masahiro Kobayashi, Shigeo Niwa, Hiroyasu Takeuchi, Mikiya Ono
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Patent number: 4735857Abstract: A fiber glass is provided for filling in a defect or hollow portion of bone. The fiber glass comprises calcium phosphate as a main ingredient and has a negative zeta potential. The calcium phosphate has a molar ratio of Ca/P of not less than 0.2 and less than 0.6 and the total content of CaO plus P.sub.2 O.sub.5 less than 80 wt %. The fiber glass is of long filament form or staple fiber form. The fiber glass of long filament form may be woven to form a woven filler.Type: GrantFiled: July 8, 1986Date of Patent: April 5, 1988Assignee: Mitsubishi Mining & Cement Co., Ltd.Inventors: Hideo Tagai, Masahiro Kobayashi, Shigeo Niwa, Hiroyasu Takeuchi, Mikiya Ono
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Patent number: 4685919Abstract: An artificial joint for joining two bones comprises first and second members each including a shank portion for attachment to one of the bones and a mating member adapted to contact the mating member of the other member to enable smooth rotation through a predetermined angle in only two directions.Type: GrantFiled: March 14, 1986Date of Patent: August 11, 1987Assignee: NGK Spark Plug Co., Ltd.Inventors: Shigeo Niwa, Kazuo Kondo, Katsutoshi Betsuki
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Patent number: 4636218Abstract: An artificial articulation includes a socket which has a spherical inner surface, a bone head ball member which is pivotably, slidably received in the spherical inner surface of the socket, and a stem which is connected to the ball head bone member. The socket is made of polycrystal alumina porcelain, the bone head ball member is made of dense silicon nitride porcelain, and the stem is made of either silicon nitride porcelain or partially stabilized zirconia porcelain. An outer surface of the stem and outer surface of the socket are coated with first and second cover layer.Type: GrantFiled: March 18, 1983Date of Patent: January 13, 1987Assignee: NGK Spark Plug Co., Ltd.Inventors: Isamu Fukuura, Shigeo Niwa
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Patent number: 4613577Abstract: A fiber glass is provided for filling in a defect or hollow portion of bone. The fiber glass comprises calcium phosphate as a main ingredient and has a negative zeta potential. The calcium phosphate has a molar ratio of Ca/P of not less than 0.2 and less than 0.6 and the total content of CaO plus P.sub.2 O.sub.5 in the fiber glass is less than 80 wt %. The fiber glass is of long filament form or staple fiber form. The fiber glass of long filament form may be woven to form a woven filler.Type: GrantFiled: June 26, 1984Date of Patent: September 23, 1986Assignee: Mitsubishi Mining & Cement Co., Ltd.Inventors: Hideo Tagai, Masahiro Kobayashi, Shigeo Niwa, Hiroyasu Takeuchi, Mikiya Ono
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Patent number: 4610693Abstract: An implanting article which includes a base body composed of a mother material and a surface portion containing dispersed apatite particles. The base body and surface portion are formed in a mold by solidifying the mother material containing apatite particles under centrifugal force. The resulting implanting article has good mechanical properties because the base body scarcely includes apatite particles in addition the article has a good affinity with a live body because the surface portion contains apatite particles densely distributed thereat.Type: GrantFiled: April 9, 1984Date of Patent: September 9, 1986Assignee: Aisin Seiki Kabushiki KaishaInventors: Shigeo Niwa, Junji Sugishita, Masami Ishii
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Patent number: 4497075Abstract: 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: GrantFiled: March 1, 1982Date of Patent: February 5, 1985Assignee: Mitsubishi Mining & Cement Co., Ltd.Inventors: Shigeo Niwa, Kazuhiko Sawai, Shinobu Takahashi, Mikiya Ono, Yoshiaki Fukuda, Hiroyasu Takeuchi, Hideo Tagai
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Patent number: 4429691Abstract: 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: GrantFiled: January 25, 1982Date of Patent: February 7, 1984Assignee: Mitsubishi Mining and Cement Company, Ltd.Inventors: Shigeo Niwa, Kazuhiko Sawai, Shinobu Takahashi, Hideo Tagai, Mikiya Ono, Yoshiaki Fukuda, Hiroyasu Takeuchi