145 results about "Mechanical axis" patented technology

An apparatus and method for tibial alignment which allows the independent establishment of two separate geometric planes to be used as a reference for the cutting of the tibial plateau during total knee arthroplasty. Two separate frame assemblies with extending rods are coupled to the tibia with a fixed relative angle between them, thereby allowing alignment with the mechanical axis of the bone. A cutting block is mounted on one of the assembly frames and is positioned against the tibia. Stabilizing pins are then placed in the cutting block, allowing the proper tibial plateau resection plane to be created.

An inertial sensor based surgical navigation system for knee replacement surgery is disclosed. Inertial sensors composed of six-degree-of-freedom inertial chips, whose measurements are processed through a series of integration, quaternion, and kalman filter algorithms, are used to track the position and orientation of bones and surgical instruments. The system registers anatomically significant geometry, calculates joint centers and the mechanical axis of the knee, develops a visualization of the lower extremity that moves in real time, assists in the intra-operative planning of surgical cuts, determines the optimal cutting planes for cut guides and the optimal prosthesis position and orientation, and finally navigates the cut guides and the prosthesis to their optimal positions and orientations using a graphical user interface.

There is described a method for determining a mechanical axis of a femur using a computer aided surgery system having an output device for displaying said mechanical axis, the method comprising: providing a position sensing system having a tracking device capable of registering instantaneous position readings and attaching the tracking device to the femur; locating a center of a femoral head of the femur by moving a proximal end of the femur to a first static position, acquiring a fixed reading of the first static position, repeating the moving and the acquiring for a plurality of static positions; and locating the centre by determining a central point of a pattern formed by the plurality of static positions; digitizing an entrance point of the mechanical axis at a substantially central position of the proximal end of the femur; and joining a line between the entrance point and the center of rotation to form the mechanical axis.

A system and method for knee arthroplasty procedures, using a novel leg rotation fixture to enable the leg mechanical axis, the tibia and the femur to be mutually disposed such that the load bearing, mechanical axis of the leg runs through the center of the knee joint. A measurement gauge is provided for mounting on the tibia and for aligning a baseplate in a known position on the tibia. This baseplate supports an X-ray target plate in a known position relative to the tibia, used in determining the mechanical axis, and an optional surgical robot, used to perform tibial and femoral cuts. The position of the femur relative to the robot may be determined from X-ray imaging of the pelvic region after attachment to the baseplate of an additional target extending to the pelvic region. The system enables improvement in the accuracy of knee arthroplasty procedures.

A method of finding the position of a mechanical axis running in the longitudinal direction through a limb that is rotatably supported by its first end in a center of rotation that is not fixed and is not accessible for the mechanical determination of coordinates, by means of an optical coordinate-measurement device with an indicator to detect measurement-point coordinates in one rotational position of the limb, such that, for each rotational position, a multi-point indicator rigidly attached near the second end of the limb signals several measurement-point coordinates, and, from the sets of measurement-point coordinates detected in a plurality of rotational positions, at least one group is selected that can be assigned to the same site of the center of rotation, and the measurement-point-coordinate sets assigned to this site of the center of rotation are used to calculate the mechanical axis.

The present invention relates to one or more tibial spacer blocks used during knee arthroplasty, each configured to be temporarily positioned upon a resected proximal portion of a tibia (essentially mimicking the tibial component of the knee prosthesis), for performing a range of motion analysis and for checking flexion and extension gaps prior to cutting the distal or posterior femur. Preferably, the spacer blocks each include an attachment arrangement configured and arranged to mate with a complementary attachment arrangement of an alignment tower and/or a femoral cutting guide. The alignment tower, which is configured to be used with an alignment rod, is used for verifying the alignment of the limb's mechanical axis when the spacer block is positioned between the tibia and the femur. The femoral cutting guide is used for guiding a cutting member into proper orientation for resecting a distal or posterior portion of a femur.

In order to avoid the use of a marking element on the pelvic bone in a method for determining the mechanical axis of a femur, with which the femur is moved about the hip joint, the movement of the femur is followed via a navigation system by means of a marking element on the femur, position data of the femur obtained therefrom are stored and the position of the mechanical axis of the femur is calculated relative to the same from the various position data of the femur in various positions, it is suggested that the femur be pivoted from an initial position only through a maximum pivoting angle of 15° in various directions and that the mechanical axis of the femur be calculated from the position data of the surface area thereby covered by the marking element and from the position data of the knee joint otherwise determined. In addition, a device for carrying out this method is described.

A method and apparatus for correcting limb alignment in a unicondylar knee arthroplasty and linking the distal femoral cut and the proximal tibial cut. Alignment rods are connected to a spacing apparatus to facilitate correction of limb alignment. The alignment rods are positioned along the mechanical axis of the femur and the tibia and the knee joint is positioned to correct alignment. A spacing apparatus is positioned in the relevant knee compartment and utilized to hold the knee in position to correct limb alignment. The spacing apparatus includes a femoral cut slot through which the distal femoral cut is made and further includes tibial affixment apertures through which a headless securing device can be positioned to secure the spacing apparatus to the tibia. After the distal femoral resection is complete, the spacing apparatus is removed, with the headless securing devices remaining positioned in the tibia. The headless securing devices are used as a reference for securing a tibial cut block to the tibia for making the proximal tibial resection. With the mechanism of the present invention, the knee can be placed in flexion when making the proximal tibial cut and the distal femoral cut is linked to the proximal tibial cut.

The invention discloses an exoskeleton type upper limb rehabilitation training robot, comprising a base, a mechanical shoulder girdle assembly, a mechanical shoulder joint assembly, a mechanical elbow joint assembly, a mechanical forearm assembly, a mechanical wrist joint assembly, a mechanical hand assembly and a motor drive assembly; The base supports the entire exoskeleton-type upper limb rehabilitation training robot, the mechanical shoulder girdle component is connected to the base, the mechanical shoulder joint component is connected to the mechanical shoulder girdle component, the mechanical elbow joint component is connected to the mechanical shoulder joint component, and the mechanical forearm component is connected to the mechanical elbow joint The components are connected, the mechanical wrist joint component is connected with the mechanical forearm component, the mechanical hand component is connected with the mechanical wrist joint component, and the motor drive component is used as the power source of the entire exoskeleton upper limb rehabilitation training robot. The invention can be used to assist human upper limbs to move in three-dimensional space and perform rehabilitation training.

Aging, injury and/or other pathologies of joints, especially weight bearing joints, contribute to changes in natural biomechanics. Deviations from optimal biomechanics lead to acceleration of the natural history of joint pathology and ultimately osteoarthritis. A Magnetic Vector Control System made up of an assembly of magnetic field sources can be disposed at or near a joint typically on or in adjacent bones of the joint, on one side of a first mechanical axis that creates a torque or moment about a second different axis of the joint, that intersects the first mechanical axis, to decrease the joint reactive force at the joint surface or equivalently substantially shift the first mechanical axis to a new or preferred position.

A device for the determination of a plane containing the mechanical axis of the femur includes a mechanical member of articulated and or/sliding elements for the determination and memorization of two positions in space (F1 and F2) of the same point (F) of the knee, freely selected, when the knee is in position P1 and P2, relative to a referential system. These positions are obtained by rotation of the inferior limb from position P1 to position P2, about the centre of the femoral head. The orientation of an omega plan perpendicular to the frontal or sagittal plane containing the centre of the femoral head and the centre of the knee can be materialized by a rod contained in this plane, which rod is fixed perpendicularly and in the middle of the arm having at the ends two localization elements for points F1 and F2.

The present invention discloses a tibia impacter provided with an alignment guide function that helps an artificial tibia implant to be adjusted to the level condition when bone cement is applied to the top surface of the cut tibia and an artificial tibia implant is driven in and fixed. The tibia impacter comprises a guide bar which is installed vertically on one side of the tibia impacter for comparison with the mechanical axis of the tibia to compare the mechanical axis of the tibia and the guide bar, so that the level condition of the artificial tibia implant mounted on the top surface of tibia can be confirmed.

The invention relates to a hydrodynamic float vane type microminiature pump, in particular to a vane type microminiature pump with no external mechanical axis, no leakage or with fluid in no contact with the external world. The invention has the technical characteristics that a main pump impeller and an electric machine rotor are integrated as a whole; auxiliary impellers are arranged at the two ends of the electric machine rotor and are symmetrically distributed with respect to the main impeller; a hydrodynamic suspension bearing is formed by the vane tops of both first and second auxiliary impellers and the corresponding inner walls of pump shells, which can realize suspended propping separately or by combining a magnetic suspension bearing. The invention can effectively form symmetrical, even and smooth flow conditions in the inner chamber of the pump shell, thus improving the hydraulic efficiency of the pump and the controllability of the flow design and further decreasing the structural size of the microminiature pumps.

The invention provides a method for estimating and accurately tracking the satellite position by using a reflector antenna. The method is different from the conventional communication antenna monopulse self-tracking or program-guided tracking methods. The method is realized by controlling the antenna mechanical axis to perform conical scanning around the satellite. The main steps are as follows: driving the antenna to perform azimuth and pitch scanning, recording the angular position information of the antenna and AGC voltage while scanning, and roughly estimating the satellite approximate position; driving the antenna to point to the satellite approximate position and perform conical scanning around the approximate position by an antenna control unit; according to the angle information and AGC voltage information output by an angle encoder during the scanning process, further estimating the satellite position by data correlation processing and the least squares method, and sending theestimation error to an antenna driving unit to realize the correction of the satellite pointing by the antenna. With the scanning and tracking going on, the method can achieve accurate tracking of satellites.

The present invention discloses a device for aligning and guiding a femoral resection guide and a femoral implant impactor, whereby the femoral resection guide and the femoral implant impactor are aligned perpendicular to the mechanical axes of the coronal plane and sagittal plane of the femur at the bottom end of the femur, and are guided so as to be rotation-aligned and mounted in parallel with a condyle axis connecting the inner condyle and outer condyle. The device comprises a main frame 110, joint bars 120 which are arranged extended downward from one end portion of the main frame 110 so as to be inserted and joined into the femoral resection guide 200 or femoral implant impactor 300, a support bar 130 which is arranged extended downward from the other end portion of the main frame 110, a first long bar 140 which is joined to the top surface of the one end portion of the main frame 110 to be arranged in parallel with the mechanical axis of the coronal plane of the femur, and a second long bar 150 which is joined to the support bar 130 to be arranged in parallel with the mechanical axis of the sagittal plane of the femur.

The present invention provides a device and method for determining the mechanical axis of a patient's limb. The device comprises a light source including a main light source arranged to project a beam of light onto the limb. The beam is adjusted to describe a plane of interest, to allow assessment of the mechanical axis of the limb.

The invention relates to an accurate measuring method for angle between optical axis and mechanical axis in optical system, belonging to the measuring technology field for angle between optical axis and mechanical axis in optical system. The purpose is that the problem that angle between optical axis and mechanical axis in satellite optical communication system can not be measured accurately in prior technology is solved. Firstly, interferometer (1) is used to adjust the optical axis of high-accuracy plane mirror (3) to coincide with the optical axis of measured optical system (2). Secondly, autocollimator (4) is used to measure the angle alpha of the optical axis and the optical axis of high-accuracy plane mirror (3). Thirdly, autocollimator (4) is used to measure the angle beta of the optical axis and the optical axis of the second high-accuracy plane mirror on mechanical base plane of measured optical system (2). Finally, according to the formula of Delta = beta - alpha the angle Delta between the optical axis and the mechanical axis is calculated. The invention can measure the angle of optical axis and mechanical axis of satellite optical communication system accurately. The measuring accuracy of angle between the optical axis and the mechanical axis is 0.2 mu rad.