摘要:
A femur head prosthesis is provided with a shank body for implanting in a femur and a pair of removeably fastened cheeks which are secured to opposite sides at a proximal end of the shank body. The cheeks can be selected from a kit of different sized cheeks. Also, each cheek has a bulge extending laterally from the shank body. Also, each cheek tapers in conically from lateral to medial and from proximal to distal.
摘要:
The acetabular prosthesis includes a metal supporting shell having collar-shaped projections which have tapered cutting edges for penetrating into the osseous tissue of a pelvic bone. The distal portions of the projections are tapered so that plugs of bone can be formed upon penetration of the projections into the osseous tissue. The projections may be filled with bone chips prior to fitting in of a plastic shell within the metal supporting shell. A multi layer metal mesh is provided on the outer surface of the metal shell for promoting fusion. If the overall attachment is not adequate, the projections can be used for insertion and centering of bone screws.
摘要:
A centering element for a shank of a femur bone prosthesis is of three-sided pyramidal shape with an equilateral triangular-shaped base. The apex of the centering element is also rounded while a stud is provided at the base for interfitting in a recess in the prosthesis shank. The shape of the centering element enables insertion of the element together with a shank in a cavity in a bone already filled with bone cement.
摘要:
A hipjoint socket has an outer cup and an inner cup disposed within and secured to the outer cup. The inner cup has a hemispherical bearing surface which is concentric with an axis and terminates at the end face, which is perpendicular to the axis. An open groove formed in the end face is concentric with the axis. A closed ring has axially relatively longer and shorter portions and a cylindrical guiding surface having a diameter about equal to a diameter of the hemispherical guiding surface. The ring includes tongues engaging the groove and thereby securing the ring to the inner cup when the ring abuts the end face. The tongues are able to slide along the groove and position the cylindrical guiding surface concentric with the axis and substantially contiguous with an end of the hemispherical bearing surface at the end face. The ring can be rotated relative to the inner cup upon the implantation of the socket to position the relatively longer ring portion on the socket where it prevents luxation of a femur head cooperating with the socket.
摘要:
An artificial acetabulum is made with a metal inner shell, a thin outer shell which defines a cavity with the inner shell and an elastic force-transmitting member between the two shells to damp forces imposed on the shells. In addition, a metal gauze layer is disposed about the outer shell for the ingrowth of osseous tissue. The inner and outer shells are connected at the edges so as to impermeable to air so that no particles from the cavity between the shells can reach the surrounding environment. A beading is also provided on the outer shell and/or gauze so as to snap into an appropriate undercut in the osseous tissue during primary implantation.
摘要:
The invention relates to an apparatus for fixing a ligament, which comprises a bone-anchoring element having a proximal end and a distal end which has a bore running in the longitudinal direction, and which comprises a clamping sleeve having a proximal end and a distal end, which clamping sleeve can be accommodated in the bore. The clamping sleeve is radially expandable, with the result that the ligament can be fixed between the clamping sleeve and the bore of the bone-anchoring element.
摘要:
Digital amplifier for amplifying a digital input signal, comprising a digital modulator for converting the digital input signal into an amplitude-discrete and temporally analogue signal, comprising an analogue error correction circuit which modulates the pulse widths of the amplitude-discrete and temporally analogue signal in dependence on an analogue error signal, comprising a power switching stage, the input of which receives the signal modulated by the error correction circuit and which delivers the modulated signal amplified at an output and comprising an analogue feedback circuit which, in dependence on the output signal of the digital modulator and on the output signal of the power switching stage, generates the analogue error signal for adjusting the analogue error correction circuit.
摘要:
The invention proposes includes a circuit that operates continuously in the time domain on the basis of the sigma-delta principle. The circuit includes at least one integrating circuit that is characterized by a first transfer function, and has a comparison circuit having a clock signal applied thereto that compares an output signal coming from the at least one integrating circuit with a reference signal and delivers a binary output signal. The circuit further includes an apparatus for signal feedback that is connected to the output of the comparison circuit and to the input of the at least one integrating circuit, and is characterized by a second transfer function. Further, an alignment device is provided that aligns the second transfer function of the apparatus for signal feedback with the first transfer function of the integrating circuit.
摘要:
A current mirror includes first through eighteenth transistors. The load paths of the first and second transistors are in series for carrying an input current to a first supply potential. The control terminals of the first through eighth transistors receive the input current. The load paths of the fourth, third, ninth and tenth transistors are in series between the first and a second supply potential. The third and ninth transistors form a tap being connected to the control terminals of the ninth, tenth, eleventh, twelfth and thirteenth transistors. The load paths of the fifth, sixth, eleventh and fourteenth transistors are in series between the first and second supply potentials. The sixth and eleventh transistors form a tap being connected to the control terminals of the fourteenth through sixteenth transistors. The load paths of the seventeenth, seventh, twelfth and fifteenth transistors are in series between the first and second supply potentials. The seventh and twelfth transistors form a tap being connected to the control terminals of the seventeenth and eighteenth transistors. The load paths of the eighteenth and eighth transistors are in series for tapping a first output current proportional to the input current from the first supply potential. The load paths of the sixteenth and thirteenth transistors are in series for tapping a second output current equal to the first from the second supply potential. The ninth through sixteenth transistors are of one, and the seventeenth, eighteenth and first through eighth transistors being of the other, conduction type.
摘要:
The invention relates to a process for the continuous treatment of silicon in which a slag in a pivotable low-shaft furnace (1) with a discharge pipe (4) reaching the bottom of the furnace tank is taken to a temperature of 1450.degree. to 1800.degree. C. and this slag is used to melt solid silicon and/or liquid silicon is continuously refined and the liquid refined silicon is then sprayed with compressed air or nitrogen (7) and continuously conveyed into a transport crucible (11) by being poured into a stream of water (9) in the channel (8) via a dewatering filter (10) and thus obtained in granular form. The invention also relates to devices for implementing the process.