Gas-spring assisted, counter-balanced L-arm assembly for fluoroscopic imaging

A method of positioning an X-ray apparatus, said method comprising the steps of:

• (a) suspending an X-ray source and an image receptor with support from a suspension means including a support arm that is rotatable about an axis of lateral rotation, wherein the X-ray source and the image receptor and the suspension means collectively comprise an X-ray assembly having a center of mass residing in a non-coaxial orientation with respect to said axis of lateral rotation;
• (b) rotating the suspension means about the axis of lateral rotation to thereby produce a gravitational torsional force about said axis of lateral rotation;
• and
• (c) counteracting the torsional force using a torsion-producing means disposed on the support arm to thereby produce counteracting torsion about the axis of lateral rotation that is opposite in direction to the gravitational torsional force.

An X-ray positioning apparatus comprising:

• a support base;
• suspension means pivotally attached to the support base for holding an X-ray source and an image receptor in a suspended position and for rotating said X-ray source and image receptor relative to said support base about an axis of lateral rotation, the suspension means including a support arm pivotally attached to the support base;
• and
• counter-balancing means, disposed on the support arm and pivotal therewith, for applying torsional resistance to the suspension means to thereby resist opposing torsional loads produced about the lateral axis.

An X-ray positioning apparatus comprising:

• a support base;
• an X-ray assembly comprising an X-ray source, an image receptor, and a suspension means pivotally connected to the support base at an axis of lateral rotation for holding the X-ray source and the image receptor in suspended positions and for rotating said X-ray source and image receptor about the axis of lateral rotation, the suspension means including a support arm pivotally attached to the support base;
• and
• compression means, disposed on the support arm and coupled to the support base, for providing added support to the X-ray assembly by applying a compression force to said X-ray assembly.

An X-ray positioning apparatus for use with X-ray diagnostic equipment, said apparatus comprising:

• a support base;
• suspension means movably coupled to the support base at a first pivotal attachment point for holding an X-ray source and an image receptor in a suspended position and for rotating said X-ray source and image receptor relative to said support base about a rotational movement path into various positions, the suspension means including a support arm pivotally attached to the support base;
• and
• reinforcing means, disposed on the support arm and movable therewith, for applying a supporting force to the suspension means in addition to any supporting force provided by the support base.

An X-ray positioning apparatus comprising:

• a support base;
• a C-arm, and an X-ray source and an image receptor mounted upon opposing locations, respectively, on the C-arm;
• a support arm pivotally attached at one end thereof to a first pivotal attachment point on the support base and slidably attached at a second end thereof to the C-arm, wherein the first pivotal attachment point coincides with an axis of lateral rotation such that the support arm is selectively rotatable relative to the support base about said axis of lateral rotation to selected lateral positions;
• a gas spring pivotally attached to a second pivotal attachment point on the support base and extending away from said second pivotal attachment point into a third attachment point on the support arm, wherein said second pivotal attachment point is spaced apart from the first pivotal attachment point;
• wherein the support arm, C-arm, X-ray source and image receptor collectively comprise an X-ray assembly having a center of mass, and wherein the second pivotal attachment point resides below the first pivotal attachment point to thereby enable the gas spring to apply a counteracting torsional force against an out-of-balance torsional force produced when the center of mass of the X-ray assembly resides out of vertical alignment with the axis of lateral rotation;
• wherein a majority portion of the support arm comprises an elongate member and wherein the gas spring comprises an elongate member, and wherein said gas spring is disposed in a nonparallel orientation with respect to said majority portion of the support arm for a majority of positions of said support arm relative to the support base to thereby produce a desired amount of torsional force about the axis of lateral rotation;
• wherein the C-arm and the X-ray source and the image receptor and the support arm collectively comprise an X-ray assembly having a center of mass that resides below the axis of lateral rotation when the support arm resides in a first, unrotated position;
• wherein the center of mass of the X-ray assembly resides at least three inches below the axis of lateral rotation when the support arm resides in the first, unrotated position;
• wherein a line extending between the second pivotal attachment point and the third attachment point is nonhorizontal and nonvertical for a for a majority of positions of the support arm relative to the support base when the X-ray positioning apparatus is disposed in a normal, operative working position, such that rotational movement of the support arm about the axis of lateral rotation produces pivotal movement at the third attachment point in multiple planes, and wherein the third attachment point comprises a universal joint;
• wherein the second pivotal attachment point resides below the first pivotal attachment point and above a center of mass of the X-ray system when the support arm resides in a first, unrotated position;
• wherein the second pivotal attachment point resides below the first pivotal attachment point by a distance within a range of approximately one inch to two inches, and wherein the center of mass of the X-ray system resides below the axis of lateral rotation by a distance of at least three inches;
• wherein the gas spring includes a means for applying a compression force to the support arm, said gas spring being connected to the support arm and to the support base in an arrangement which, in combination with the compression force, operates to produce a counteracting torsional force about the axis of lateral rotation substantially equivalent to an opposing torsional force produced about said axis of lateral rotation by force of gravity when the support arm is disposed in a displaced, rotated position;
• wherein the C-arm and the X-ray source and the image receptor and the support collectively comprise an X-ray assembly having a center of mass, and wherein said center of mass being spaced-apart from the axis of lateral rotation by a separation distance and is thereby disposed in an orbital movement path about said axis of lateral rotation by rotational movement of the support arm, and wherein a combination of the separation distance and amount of weight of the X-ray assembly requires the compression force applied by the gas spring to exceed nine hundred pounds in order to produce the counteracting torsional force that is substantially equivalent to the opposing torsional force produced by force of gravity;
• wherein the support arm comprises an elongate member having a central axis, and wherein the gas spring comprises an elongate member having a central axis that remains in a nonparallel orientation with respect to the central axis of the support arm;
• wherein the entire gas spring resides inside the support arm;
• wherein the gas spring comprises an expansion/contraction means for expanding responsive to upward pivotal movement of at least a portion of the suspension means and contracting responsive to downward pivotal movement of said portion of the suspension means.