53results about How to "Accurate angular position" patented technology

A multiportal device for percutaneous surgery consists of a guiding device with a radial arm that supports an auxiliary guiding device, which can slide along the arm and can be fixed in a require angular position on the arm. The device also includes a first cannula, which can be inserted into the patient's body through the guiding device and can be fixed in a required axial position, and a second cannula, which can be inserted into the second guiding unit and fixed therein. The arch-shaped form of the arm ensures intersection of distal ends of both cannulae in one point aimed at the symptomatic site where surgery has to be done. The device is provided with a linking mechanism that links the distal ends of both cannulae in their position inside the body of a patient. In the engaged state of the linking device, the cannulae still have some freedom of relative movements that may be required for manipulation with cannulae during the surgery. The invention also relates to a method of using the multiportal device for percutaneous surgery. The device allows insertion of a plurality of cannulae and permanently maintaining them in controlled positions without resorting to additional X-ray.

A contactless rotary shaft position sensor provides for precision computation of shaft angle for a wide range of input shaft rotational angles. The sensor includes two annular two-pole magnets which are connected by a precision, motion-transmitting gear train. An optional second gear train between one of the magnets and the input shaft can provide additional angular rotation scaling to accurately measure either fractional or a large number of multiple turns of the input shaft. The gear ratios are selected such that one of the magnets does not rotate more than one revolution. Pairs of ratiometric Hall-effect or magnetoresistive sensors provide differential voltage signals which are used for sensing angular position of each magnet over a full 360 degrees of rotation. The single-turn magnet provides an absolute, coarse indication of input shaft rotation with a typical accuracy of 2%. The gear ratio between the magnets produces several turns of the second magnet for each turn of the single-turn magnet. Since the gear ratio between the magnets is fixed, the angle sensed for the multi-turn magnet can be predicted from the position of the single-turn magnet. This is compared to the multi-turn magnet's actual sensed rotation. The result is an improvement in accuracy directly proportional to the gear ratio between the magnets. Computation of the individual magnet rotation angles and the input shaft angle is performed using a microprocessor and appropriate signal conditioning circuits. Utilizing two magnets, input shaft rotation can be accurately measured to within 0.1% of maximum range.

An apparatus and method for reducing and fixing fractures, for example, a proximal humeral fracture. A jacking device releasably attached to a locking plate presses against an inferior aspect of the head to rotate the head into anatomic alignment. Suture material stitched into the soft tissue superior to the head pulls the superior end of the head and guides and steers the head. The suture material passes through suture holes in the superior end of the plate. The jacking device positions and holds the head in an anatomic neck/shaft angle, thereby allowing the head to be fixed to the locking plate. In one such embodiment, a swivel bushing in the plate receives the jacking device and allows the angle of the device to be adjusted as desired. To aid in the fluoroscopic visualization during surgery, a radiolucent retractor is used to avoid blocking the surgeon's view.

A specimen positioning mechanism (10) includes a movable stage (12) movable along multiple axes, a plate (35) connected to and supporting a specimen mounting chuck (14), multiple linear displacement mechanisms (36, 38) coupling the plate to the movable stage and mutually spaced apart at different locations between the movable stage and the plate and separately controllable to change distances between the movable stage and the plate, and a flexible member (22) coupling the movable stage and the plate. The flexible member is motion compliant in three axes of motion. The flexible member in response to linear displacements of the linear displacement mechanisms allows linear and rotational movement of the specimen mounting chuck in the three axes of motion compliance.

Two transducers to be rotated around a circumferential location on a cylindrical body for structural testing of the body are carried on a mounting and drive apparatus including a magnetic attachment which can be manually brought up to a pipe from one side only for fixed connection to the pipe on that side at a position axially spaced from a weld. A collar shaped support for the pair of transducers is formed of a row of separate segments which wrap around the pipe from the one side and is rotated around the axis of the pipe to carry the transducer around the circumferential weld. The segments carry rollers to roll on the surface and are held against the pipe by magnets. The transducers are carried on the support in fixed angular position to track their position but in a manner which allows slight axial or radial movement relative to the pipe.

A urological resectoscope is disclosed, having a tubular shaft (1), through which an optical system (2) and a longitudinally moveable instrument carrier (5) pass. The optical system (2) is supported with respect to the tubular shaft (1) at a spacing from the proximal end of the tubular shaft (1) with a support device (9, 12). The carrier (5) is positioned with a radial positioning device (10, 15) and a circumferential angular positioning device (11, 12). The support device (12, 18, 18′) is so arranged adjacent to the optical system (2) in the region in which the carrier (5) extends, that it supports the optical system (2) with respect to the tubular shaft (1) with a two point support system and imparts lateral guidance to the carrier (5) in the circumferential angular direction.

The invention concerns a device produced in the form of an assembly which can be integrated in any installation (13) for radioscopy of the product and comprising means for driving the product (5) in rotation about an axis (5a) perpendicular to the tomographic section plane to be obtained, a unit controlling (15, 16) the means (14) driving the product (5) in rotation, to drive the product (5) in rotation about the axis (5a) and an image acquisition and processing unit (16) including means for automatically acquiring and storing radioscopy images of the product (5) while the product (5) is rotating, in digital form, and calculating means for processing the digital images and constructing tomographic sections using a calculating algorithm. The device enables fault controls or geometrical and dimensional controls in mechanical parts for the automotive industry such as cylinder heads.

The present invention discloses a power conversion circuit. A control module controls a pulse width modulation regulator to regulate a duty cycle of a DC-DC converter according to the direct current link voltage of the DC-DC converter and the output current and voltage of a renewable power supply. The control module also controls the pulse width modulation regulator to regulate a duty cycle of a DC-AC inverter according to the direct current link voltage of the DC-DC converter, output voltage of a utility power supply, and the output current and voltage of the renewable power supply.

Method of predicting the deformation of a workpiece (13) prior to machining that causes the workpiece to deform through release of residual stresses, which method consists in emitting a beam of ultrasound waves onto the surface of the workpiece (13) in such a way that a longitudinal wave (12) is propagated substantially parallel to and under the surface of the workpiece (13), then in measuring the propagation velocity of the subsurface longitudinal wave in a first region (A) sensitive to residual stresses and in a second region (B) somewhat insensitive to residual stresses, then in calculating the difference in the measured velocities and from this deducing the deformation that will result from machining the first region of the workpiece (13).

The invention relates to a magnetic flux collector for a torque detection device. The collector includes two coaxial magnetic cylinder heads (6, 7), having respectively interlocked teeth (17, 28), overmoulded by means of a plastic material. The two cylinder heads (6, 7) have, at the periphery thereof, notches (18, 19, 23) provided such as to engage with matching grooves (32, 33) which comprise a cylindrical cavity (31) of a mould (30) for overmoulding the cylinder heads with the plastic material. The two cylinder heads (6, 7) are therefore positioned in a very accurate manner relative to one another, before injecting the overmoulding plastic material. The invention can be used for the production of torque sensors used in the power-steering systems of automobiles.

A method for determining the angular position of a synchronous machine having a magnetically anisotropic rotor includes an (m) iteration stage and an (n) iteration stage. The (m) iteration stage encompasses: generating an (m) magnetic field of an (m) angular direction and acquiring an (m) peak value of the current pulse generated by the (m) voltage pulse; and providing at least two further (m+i) peak values in different (m+i) angular directions that differ from the (m) angular direction. The (n) iteration stage includes: ascertaining the angular directions (n) and (n+1) in which the two highest or the two lowest peak values from a peak value group occur; and providing an (n) angular direction, which resides between the (n+1) angular direction and the (n+2) angular direction, as an angular position output.

A flow sensor comprises a measuring chamber, into which a medium may be introduced and then removed, the volume and/or flow speed of which is to be measured. Freely rotating measuring elements are mounted in the measuring chamber Furthermore, at least one sensor for the measurement of magnetic fields and/or changes in magnetic fields is provided and a circuit to which the output signals from the sensor(s) are supplied. The sensor(s) provide an output signal and supply the same to the circuit. The output signal varies periodically on each passage of a single tooth and a corresponding tooth gap on one of the measuring elements, between a minimum and a maximum value. Depending on the position of the tooth relative to the sensor(s) the output signal takes on a reproducible intermediate value. The circuit is embodied such as to convert the intermediate values into discrete values, representative of part volumes of the volumes pumped between two teeth.

A camshaft has at least two completely machined individual cams fixedly mounted on a shaft in predetermined angular positions. The shaft includes an outside shaft and an inside shaft arranged concentrically in the former, and is to be manufactured in such a way that remachining of the joined camshaft is not necessary. This is by combining the individual cams even before they are mounted on a shaft and joining them to this shaft to form a machining module, such that the individual cams are combined in their mutual arrangement in relation to one another in which the cams are to be mounted on the finished camshaft. The final machining of the cams is performed within this machining nodule. When the cams are completely machined in this way, the cams are joined to the shaft of the camshaft within the machining module. This ensures that the desired mutual arrangement is maintained, i.e., that remachining is not necessary.

A swiveling device for a swiveling C-arm of an X-ray unit includes a motorized drive unit and an adapter removably attachable to the C-arm concentrically with a swiveling axis thereof. The adapter connects the C-arm to the drive unit in driving manner. The swiveling device also includes an angular position encoder for recording the swivel angle of the C-arm.

The invention provides a motor control method and system based on a hall sensor, and relates to the field of motors. In the motor control method based on the hall sensor, after a motor is operated, firstly, whether at least one hall sensor in a hall sensor group in the motor breaks down or not is judged; and if at least one hall sensor breaks down, then whether the hall sensor group can work in afault mode or not is judged. If the hall sensor group can work in the fault mode, the angle of a rotor and a preset coordinate axis arranged on a stator is calculated according to a first calculationmethod; and finally, vector control is carried out on the motor according to the angle. By adopting the method, when the motor operates, the hall sensor is firstly subjected to fault diagnosis, so that it is ensured that the calculated angle position is accurate and credible. Meanwhile, when the hall sensor breaks down severely, the motor is forbidden to run, so that the safety of the vehicle is ensured.

A data medium is driven by a brushless direct current motor and possesses control signals on a track which can be picked up by a sensing device and supplied to a switch arrangement for activation of the motor winding. The control signals on the track characterize at least those angular positions of the rotor with respect to the stator in which commutation is to be initiated.