US 7,029,478 B2Granted

Method and apparatus for distal targeting of locking screws in intramedullary nails

AssigneeDePuy Products, Inc.

InventorsDavid Stuart Hollstien, Roy B. Hollstien

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Abstract

A system that enables axis-to-axis targeting of an instrument placed within a drill bushing includes a computer, a probe, and a pair of sensor planes mounted to a drill bushing so the planes are perpendicular to one another. The probe has two drive coils that may be mounted near its distal end. The two coils are placed close to one another and are oriented so that when they are selectively coupled to an alternating current source they generate magnetic fields that are orthogonal to one another. The computer receives electrical signals from the sensors in the sensor planes and computes target position, bushing alignment, and bushing orientation values. These values may be presented on a display associated with the computer or used to illuminate directional arrows associated with the drill bushing.

Claims31

Dependent claims

A system for locating a target point for a drill bushing comprising:

a probe having two drive coils, the drive coils being mounted in the probe and being oriented so that a magnetic field produced by the first drive coil in response to an alternating current being coupled to the first drive coil is orthogonal to a magnetic field produced by the second drive coil in response to an alternating current being coupled to the second drive coil;
a guide having a pair of sensor planes mounted proximate a drill bushing, the sensor planes being orthogonal to one another, each sensor plane containing a pair of sensors, each sensor generating an electrical signal in response to magnetic fields produced by the first and the second drive coils;
and
a computer coupled to the sensors in each sensor plane to receive signal readings from each sensor and to determine the target point of the drill bushing to which the pair of sensor planes is mounted.

1 more element

Dependencies are inferred from the claim text.