164.
    发明专利
    未知

    公开(公告)号:NL8701026A

    公开(公告)日:1988-11-16

    申请号:NL8701026

    申请日:1987-04-29

    Abstract: Negative-feedback amplifier provided with an active amplifier section operating approximately as a nullor and a negative feedback section, the amplifier having a high loop gain. The active amplifier section is constructed in balanced form with two nullors connected in balance, and the negative-feedback section is composed of passive impedances and comprises two negative-feedback loops. In one embodiment each nullor has a series-coupling circuit and a parallel-coupling circuit at the input port. Thereby an accurately defined or characteristic input impedance is obtained, and a series- or parallel-coupling circuit is formed in both negative-feedback loops at the output port, so that a high (current output) or low (voltage output) output impedance respectively is obtained. In another embodiment each nullor has a series-coupling circuit and a parallel-coupling circuit at the output port. Thereby an accurately defined or characteristic output impedance is obtained at the amplifier, an a current or voltage related both to the output current and voltage is fed to the input port, so that a low (current input) or high (voltage input) input impedance respectively is obtained.

    Implantation system for treatment of a defective curvature of the spinal column.

    公开(公告)号:AU2012380394A1

    公开(公告)日:2014-12-04

    申请号:AU2012380394

    申请日:2012-05-16

    Abstract: An implantation system for treatment of a defective curvature of the spinal column comprises an elongated element (2), a first bone fixation element (31) being fixedly attached to said elongated element, a second bone fixation element (32, 33), and guiding structure (45, 50) through which the second bone fixation element is slidably and contactingly connected to the elongated element. The elongated element has bending resilience and/or torsional resilience for applying corrective force action to the spinal column. A special arrangement of the guiding structure (45, 50) provides automatical adjustment of the corrective force action in dependence of growth of the spinal column. The system allows for good flexibility of the spine and for a natural healthy growth of the spine, while it avoids re-operations and implant adjustments.

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