Nakashima Medical Co.

Kita-ku, Japan

Nakashima Medical Co.

Kita-ku, Japan

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Patent
Ryutaku and Nakashima Medical Co. | Date: 2011-09-13

A bone resection jig that can make ligament tension equal at extension and flexion positions without any actual measurements when resecting femur and tibia during artificial knee joint replacement surgery. The bone resection jig used in artificial knee joint replacement surgery includes a spacer block (1) comprised of a grip (6), a hollow box (7) that is provided on an other end side of the grip and has a vertical hole (7a) therein, and a reference spacer part (8) that extends out from the hollow box (7) and is adapted be inserted into the resection region between femur and tibia; a reference pin guide (2) which, when the femur and tibia are in the flexion position, is inserted into the vertical hole (7a) of the hollow box, extends on the reference spacer part (8) to the other end side of the grip so as to come into contact with a resection plane (F_(H)) of the tip of the distal end of the femur, and is formed with guide holes (9) for guiding reference pins (3) to be installed from a front side into the resection plane (F_(H)) of the tip of the distal end of the femur; and an aiming member (12) which is, after the spacer block (1) has been removed from a space between the femur and tibia leaving the reference pins (3), brought onto the reference pins (3) by being guided thereby, the aiming member being provided with an indicator (14) that indicates a resection plane (F_(R)) at a back of the distal end of the femur when the aiming member (12) comes into contact with the resection plane (F_(H)) of the tip of the distal end of the femur.


Patent
Nakashima Medical Co. and Kaneyama Ryutaku | Date: 2013-07-24

A bone resection jig that can make ligament tension equal at extension and flexion positions without any actual measurements when resecting femur and tibia during artificial knee joint replacement surgery. The bone resection jig used in artificial knee joint replacement surgery includes a spacer block (1) comprised of a grip (6), a hollow box (7) that is provided on an other end side of the grip and has a vertical hole (7a) therein, and a reference spacer part (8) that extends out from the hollow box (7) and is adapted be inserted into the resection region between femur and tibia; a reference pin guide (2) which, when the femur and tibia are in the flexion position, is inserted into the vertical hole (7a) of the hollow box, extends on the reference spacer part (8) to the other end side ofthe grip so as to come into contact with a resection plane (F_(H)) of the tip of the distal end of the femur, and is formed with guide holes (9) for guiding reference pins (3) to be installed from a front side into the resection plane (F_(H)) of the tip of the distal end of the femur; and an aiming member (12) which is, after the spacer block (1) has been removed from a space between the femur and tibia leaving the reference pins (3), brought onto the reference pins (3) by being guided thereby, the aiming member being provided with an indicator (14) that indicates a resection plane (F_(R)) at a back of the distal end of the femur when the aiming member (12) comes into contact with the resection plane (F_(H)) of the tip of the distal end of the femur.


Patent
Nakashima Medical Co. and Kaneyama Ryutaku | Date: 2014-01-01

In a surgical operation for replacing artificial knee joints, before a regular (genuine) implant is mounted as a femur-side member, a resection is performed along a pre-cut line shallower than a genuine-cut line, and a pre-cut trial is mounted; and the extended position and the flexed position and the rotation during flexion are observed, so that it is judged whether the set-up genuine-cut and implant are appropriate. A pre-cut trial is mounted on a pre-cut line which is cut shallower than a genuine-cut line, and the extended and flexed positions of a femur and the state of flexion thereof are observed so as to make judgment whether the genuine implant is appropriate, the pre-cut trial being modeled after the genuine implant which is mounted on resected surfaces formed by genuine-cut performed so as to form the end resected surface, posterior and anterior resected surfaces, and the posterior and anterior chamfer-resected surfaces on the distal end of the femur.


Saito N.,Shinshu University | Haniu H.,Shinshu University | Usui Y.,Shinshu University | Aoki K.,Shinshu University | And 11 more authors.
Chemical Reviews | Year: 2014

Carbon nanotubes (CNT) are structurally described as sheets of six-membered carbon atom rings rolled up into cylinders. CNTs with only one layer are known as single-walled CNTs (SWCNT), and those with two or more layers are known as multi-walled CNTs (MWCNT). The reasons are that CNTs have useful electrical, thermal, and mechanical characteristics, and their base material performance can be improved by combination with other materials. A recent industrial application of CNTs as an electrode additive to lithium-ion batteries is based on their excellent electrical characteristics. One reason for the intense competition to find biomaterial applications of CNTs and for the great potential of CNTs to advance medical care is their small size, which makes them suitable to react with living organisms.


Noyama Y.,Osaka University | Noyama Y.,Nakashima Medical Co. | Nakano T.,Osaka University | Ishimoto T.,Osaka University | And 2 more authors.
Bone | Year: 2013

We proposed a novel surface modification for an artificial hip joint stem from the viewpoint of maintenance and establishment of appropriate bone function and microstructure, represented by the preferred alignment of biological apatite (BAp) and collagen (Col). Oriented grooves were introduced into the proximal medial region of the femoral stem to control the principal stress applied to the bone inside the grooves, which is a dominant factor contributing to the promotion of Col/BAp alignment. The groove angle and the stem material were optimized based on the stress inside the grooves through a finite element analysis (FEA). Only the groove oriented proximally by 60° from the normal direction of the stem surface generated the healthy maximum principal stress distribution. The magnitude of the maximum principal stress inside the groove decreased with increasing the stem Young's modulus, while the direction of the stress did not largely changed. An in vivo implantation experiment showed that this groove was effective in inducing the new bone with preferential Col/BAp alignment along the groove depth direction which corresponded to the direction of maximum principal stress inside the groove. The anisotropic principal stress distribution and the oriented microstructure inside the groove are similar to those found in the femoral trabeculae; therefore, the creation of the oriented groove is a potent surface modification for optimizing implant design for a long-term fixation. © 2012 Elsevier Inc.


Uetsuki K.,Nakashima Medical Co.
Transactions of Japanese Society for Medical and Biological Engineering | Year: 2014

Many researches, such as wear resistance enhancement and metal surface modification for bone-implant bonding, have been conducted in order to improve the performance and function of artificial joint. In 2010, Nakashima Medical Co., Ltd. has launched Vitamin-E (dl-α-tocopherol) blended UHMWPE as knee joint bearing material that is expected superior durability. And then, as a hip joint bearing material, crosslinked Blend-E was placed on market in 2013. These materials have different properties in consideration of each biomechanics. In this paper, we report about our development of biomaterials, especially of the Vitamin-E blended UHMWPEs, BLEND-E® and BLEND-E® XL. © 2014, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved.


Patent
Nakashima Medical Co. | Date: 2011-10-21

A surgical instrument including a pre-cut trial mounted on a pre-cut line which is cut shallower than a genuine-cut line. The pre-cut trial is modeled after the genuine implant which is mounted on resected surfaces formed by performing genuine-cutting and comprised of an end resected surface, posterior and anterior resected surfaces, and posterior and anterior chamfer-resected surfaces on the distal end of a femur, and the pre-cut trial is mounted on the pre-cut line, thus observing the extended and flexed positions of the femur and the state of flexion thereof so as to make judgment if the genuine implant is appropriate.


Patent
Nakashima Medical Co. | Date: 2010-09-30

A shock absorbing structure having a high shock absorption characteristic is provided. The shock absorbing structure includes a solidified portion and a sintered portion. The solidified portion is formed by dissolving and solidifying a plurality of inorganic powder particles. The sintered portion is formed by sintering a plurality of the inorganic powder particles. The sintered portion is connected to the solidified portion. The shock absorbing structure is a composite structure including the solidified portion and the sintered portion and therefore has a high shock absorption characteristic.


Patent
Nakashima Medical Co. | Date: 2011-01-07

A surgical assistance system for operating on biological tissue using a surgical tool attached to an arm of an automatically-controlled surgical instrument so that an optimal feed rate of the tool is calculated and outputted to the surgical instrument, the system including: a device for storing and voxelizing medical image data obtained from a biological tissue subject to surgery; a device for setting an operative location based on the shape of the biological tissue; a device for calculating a tool path along which the tool travels to perform surgery at an operative location; a device for determining the region of interference between the tool and the voxels; a device for determining the hardness of the biological tissue in the interference region; a device for calculating an optimal tool feed rate corresponding to the hardness; and a device for outputting the feed rate obtained by the calculations to the surgical instrument.


Patent
Nakashima Medical Co. | Date: 2012-11-07

A shock absorbing structure having a high shock absorption characteristic is provided. The shock absorbing structure (1) includes a solidified portion (2) and a sintered portion (3). The solidified portion (2) is formed by dissolving and solidifying a plurality of inorganic powder particles. The sintered portion (3) is formed by sintering a plurality of the inorganic powder particles. The sintered portion (3) is connected to the solidified portion (2). The shock absorbing structure (1) is a composite structure including the solidified portion (2) and the sintered portion (3) and therefore has a high shock absorption characteristic.

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