Stirrups compatible with imaging systems

Abstract

An apparatus for supporting a limb of a patient during imaging and treatment procedures is provided. The apparatus has an extension having a distal end portion and a proximal end portion; a limb support coupled to the distal end portion; a clamp configured for attachment to a rail at a lateral side of a patient support; a knuckle coupled to the proximal end portion and to the clamp; and a handle located at the distal end portion and coupled to the knuckle, such that the handle selectively actuates the knuckle to limit the spherical movement of the extension relative to the clamp. An overall width of the patient support and the apparatus with the clamp attached to the rail does not exceed a dimension of the bore of an imaging machine. The apparatus is compatible for use within the bore and during operation of the imaging machine for various procedures.

Description

[0001] STIRRUPS COMPATIBLE WITH IMAGING SYSTEMS

[0002] CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This Application is related to and claims the benefits of priority of U.S. Provisional Application No. 63 / 641,824, filed May 2, 2024, entitled STIRRUPS COMPATIBLE WITH IMAGING SYSTEMS, the content of which is incorporated herein by reference in its entirety for all purposes.

[0004] FIELD OF THE INVENTION

[0005] The present invention is directed to stirrups designed to support a patient's lower extremities during imaging and treatment procedures. The stirrups are configured to provide such support while positioned within the bore of an imaging machine, such as a magnetic resonance imaging (MRI) scanner or computed tomography (CT) scanner.

[0006] SUMMARY OF THE INVENTION

[0007] The present invention is directed to stirrups designed to support a patient's lower extremities during imaging and treatment procedures. The stirrups being configured to provide such support while positioned within the bore of an imaging machine, such as a magnetic resonance imaging (MRI) scanner or computed tomography (CT) scanner. In a preferred embodiment of the present invention, the stirrups as described in an embodiment of the present invention utilize tension to provide a counterforce to the weight of the patient's legs, assisting the clinician with positioning the legs in the desired configuration and reducing the risk of the legs suddenly lowering during adjustment. Contrary to alternative stirrups, in embodiments of the present invention, structures critical to adjusting and maintaining the position of the patient's anatomy are located within the boundaries of the patient support, and thus within the maximum bore diameter or arc radius of an imaging and / or treatment machine.

[0008] In some aspects, additional features such as non-conductive components allow for the stirrup to receive an MR-conditional rating, thereby eliminating the need to remove and reapply stirrups in the course of procedures utilizing MR imaging.

[0009] According to aspects of the invention, an apparatus for supporting a limb of a patient during imaging and treatment procedures is provided. The apparatus is configured to provide access to a pelvic region of the patient and to enter a bore of a magnetic resonance imaging scanner. The apparatus includes an extension having a distal end portion and a proximal end portion; a limb support coupled to the distal end portion of the extension; a clamp configured for attachment to a rail at a lateral side of a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner; a knuckle coupled to the proximal end portion of the extension and to the clamp, the knuckle being configured to enable spherical movement of the extension relative to the clamp, and the knuckle having a brake configured to limit the spherical movement of the extension relative to the clamp; and a handle located at the distal end portion of the extension and coupled to the brake of the knuckle, the handle being configured to selectively actuate the brake of the knuckle to limit the spherical movement of the extension relative to the clamp. The clamp has a rail mounting portion configured for attachment to the rail of the patient support and a knuckle mounting portion coupled to the knuckle. The knuckle mounting portion is configured such that the knuckle is positioned laterally inward toward the rail of the patient support when the clamp is attached to the rail of the patient support. . An overall width of the patient support and the apparatus with the clamp attached to the rail of the patient support does not exceed a dimension of the bore of the magnetic resonance imaging scanner. The apparatus is compatible for use within the bore of the magnetic resonance imaging scanner and during operation of the magnetic resonance imaging scanner for imaging and treatment procedures.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects and features of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0012] Figure 1 shows an aspect of a stirrup of an embodiment of the present invention. Figure 2 shows an aspect of a stirrup of an embodiment of the present invention. Figure 3 shows an aspect of proximal portion of a stirrup of an embodiment of the present invention.

[0013] Figure 4 shows an aspect of a stirrup of an embodiment of the present invention. Figure 5A shows the location of structures of stirrups located outside of the boundaries of a patient support.

[0014] Figure 5B shows the relationship of the bore width of an exemplary imaging machine to the total width of alternative stirrups.

[0015] Figure 6A shows the location of structures of the stirrups of an embodiment of the present invention located within the boundaries of a patient support.

[0016] Figure 6B shows the relationship of the bore width of an exemplary imaging machine to the total width of the stirrups of an embodiment of the present invention. Figure 7A shows alternative stirrups.

[0017] Figure 7B shows a side view of the stirrups of an embodiment of the present invention. Figure 8 shows alternative stirrups.

[0018] Figure 9 is a perspective view of an exemplary embodiment of a stirrup in accordance with aspects of the invention.

[0019] Figure 10A is a partially exploded view of the stirrup of Figure 9.

[0020] Figures 10B and 10C are magnified detailed views showing portions of the stirrup of Figure 10A.

[0021] Figure 11 is an exploded view of an exemplary boot subassembly of the stirrup of Figure 9 in accordance with aspects of the invention.

[0022] Figure 12A is an exploded view of an exemplary actuator handle assembly and tube subassembly of the stirrup of Figure 9 in accordance with aspects of the invention. Figure 12B is a magnified detailed view of an exemplary actuator handle assembly of the actuator handle assembly and tube subassembly of Figure 12A in accordance with aspects of the invention.

[0023] Figure 12C is a side view of the stirrup of Figure 9.

[0024] Figure 12D is a cross-section view of the actuator handle assembly, taken along line 12D-12D of the stirrup of Figure 12C.

[0025] Figures 12E-12F depict views of the actuator handle assembly of Figure 12B during operation of the stirrup of Figure 9.

[0026] Figure 12G is a magnified detailed view of an exemplary distal end of the actuator handle assembly and tube subassembly of Figure 12A in accordance with aspects of the invention.

[0027] Figure 12H is a side view of a portion of the distal end of Figure 12G.

[0028] Figure 13A is an exploded view of an exemplary clamp knuckle assembly of the stirrup of Figure 9 in accordance with aspects of the invention.

[0029] Figure 13B is a top plan view of the stirrup of Figure 9.

[0030] Figure 13C is a cross-section view of the clamp knuckle assembly of Figure 13A, taken along line 13C-13C of the stirrup of Figure 13B.

[0031] Figure 13D is a magnified detailed view of a portion of the clamp knuckle assembly of Figure 13C.

[0032] Figures 13E-13F depict portions of the actuator handle assembly and tube subassembly of Figure 12A and the clamp knuckle assembly of Figure 13C during operation of the stirrup of Figure 9.

[0033] Figure 14A depicts an exemplary shock subassembly of the stirrup of Figure 9 in accordance with aspects of the invention.

[0034] Figure 14B is an exploded view of the shock subassembly of Figure 14A. DETAILED DESCRIPTION OF THE INVENTION

[0035] Image-guided procedures in gynecology and urology are becoming increasingly more common with improved access to imaging machines such as computed tomography (CT) machines, magnetic resonance imaging (MRI) machines, and C-arm x-ray machines, as well as radiotherapy applications such as brachytherapy. As procedures in these clinical fields typically require access to a patient's anatomy such as their perineum, stirrups designed to position the patient's legs to facilitate this access (for example, in a lithotomy position) are utilized. Exemplary stirrups of the prior art are designed such that they are removably attached to industry standard mounting rails incorporated into procedure tables and other patient support surfaces, patient transfer devices, and other treatment devices. However, structural characteristics of these exemplary stirrups of the prior art can create dimensional clearance issues with the patient-receiving bores or arcs of imaging and treatment equipment. Due to the configuration of components, the joint which enables a range of movement necessary to position the patient can be located far outside of the boundary created by the mounting rails on the patient support surface. Because of this, a patient support surface equipped with stirrups may be too wide to fit in the typically-sized bores of conventional imaging machines.

[0036] The present invention describes stirrups which resolve these dimensional clearance issues, enabling the imaging of a patient with legs in a lithotomy or other selected treatment position while minimizing the bore diameter required to accommodate a patient and aiding in collision avoidance.

[0037] According to an embodiment of the present invention, a pair of stirrups 10 are provided, comprised of several features. Each stirrup 10 is provided with at least one extension with at least one limb support 20 provided on a first end located distally to the patient's pelvis of the at least one extension 12 to receive the patient's lower limb. This at least one limb support 20 may be either permanently or removably attached to the extension 12, however, in a preferred embodiment is adjustable to accommodate the angle and length of the patient's legs for enhanced comfort and stability of the patient's lower extremities. The at least one limb support 20 may also feature straps or other means to secure the patient's lower limb within the limb support 20. In a preferred embodiment, the limb support 20 is configured to support at least one of the patient's calf, knee, or foot. On a second end, proximal to the patient's pelvis, the at least one extension 12 is coupled to joint or pivot such as a knuckle 30. The knuckle 30 is configured such that it enables spherical or orbital motion of the extension 12 around the knuckle 30. This spherical motion allows the stirrup 10 to rotate, abduct, and / or adduct the patient's lower extremities to suitably position the patient for their imaging or treatment procedure. Features may additionally be provided on each stirrup 10 to independently lock each stirrup 10 in place at a desired angular or rotational position of the at least one extension. In a preferred embodiment, the knuckle 30 is further configured such that it has a brake connected via cable or other means to a feature provided on the first, distal end of the extension 12 on each stirrup 10. This brake is configured to limit the motion of the knuckle 30, thereby locking the position of the at least one extension 12 in the desired position. In a further preferred embodiment, this feature may be a handle or other similar structure which enables the clinician to independently manipulate the position of the patient's legs, then actuate the handle to engage the brake on the knuckle 30 via the cable. In a further preferred embodiment, the spherical or orbital motion enabled by the knuckle 30 is configured such that the angular and rotational position of the extension 12 are related to an extent, so as to better simulate the range of motion of a typical patient's hip joint. Typically, this range is up to approximately 30 degrees in a lateral motion and up to approximately 10 degrees in a medial motion.

[0038] In a preferred embodiment, each stirrup 10 further comprises at least one post and at least one clamp. In a further preferred embodiment, the at least one post may be a blade or a plate, which is flat in shape so as to economize on space in the assembly. The clamp is configured to receive accessory rails as typically found on opposite sides of various patient support modalities, enabling each stirrup 10 to be secured to the appropriate patient support modality. The clamp is also configured to accept the at least one post on the top portion of the at least one clamp. The at least one post has both a medial aspect and lateral aspect. The knuckle 30 is coupled to the at least one post on its medial aspect and is additionally located relatively above the at least one clamp.

[0039] In a further preferred embodiment, each stirrup 10 may be further provided with at least one structure 40 configured to act as a counterweight to the patient's leg. This reduces the amount of force required to manipulate the patient's leg positioned in the stirrup 10 by providing a resistance to the patient's leg being suddenly lowered under the influence of gravity when the brake is unlocked and the rotational and angular position of the at least one extension 12 is being manipulated. This structure 40 configured to act as a counterweight may be any one of the following, non-exhaustive examples, including a compression shock, spring-damper system, separated damper and spring, gas strut, gas cylinder with spring assisted return, or another suitable structure known to one having ordinary skill in the art. In a preferred embodiment, the structure 40 providing the counterweight function is a compressive shock. In a further preferred embodiment, this structure 40 configured to act as a counterweight is located in a position such that it does not interfere with the structure of the underlying patient support or the patient space. In particular, the structure 40 configured to act as a counterweight is located relatively above the knuckle 30. In this embodiment, the structure 40 configured to act as a counterweight further has a first distal end, coupled to the at least one extension 12 at a point between the at least one foot support 20 and the knuckle 30, and a second proximal end coupled to the medial aspect of the at least one post, relatively above the knuckle 30.

[0040] In the configuration of components in an exemplary alternative stirrup, a gas shock can be positioned underneath the joint, and as a result, it and the joint are can be located outside of the boundary created by the mounting rails on the patient support surface, to avoid dimensional interference with the patient support. However, in avoiding one dimensional interference issue, a new issue is introduced - the width between the outermost surface of the stirrups may be wider than the width of a patient support. This additional width poses a challenge where space is constrained, such as in imaging environments such as magnetic resonance imaging (MRI), computed tomography (CT), and C-arm X-ray systems. Exemplary imaging machines typically have a fixed bore diameter or arc radius, designed to accommodate the width of the patient support included with the imaging machine with little to no room for overage. The configuration of the alternative stirrups exceeds this bore diameter or arc radius on typical imaging and treatment systems and thus can limit the use of such stirrups in these environments, in some applications. This means that a patient may need to be repositioned in order to be treated or imaged, which is not ideal during procedures conducted under image guidance. The configuration as described in an embodiment of the present invention results in a stirrup 10 or a pair of stirrups 10 wherein the structures used for adjusting and maintaining the position of the patient's anatomy - the structure 40 configured to provide counterweight and the knuckle 30 - are located within the boundaries of the patient support or laterally inward toward or at or near the lateral sides of the patient support, and thus within the maximum width of the bore of an MRI or CT scanner, thereby eliminating the need to position and reposition the patient in the course of procedures utilizing imaging.

[0041] In yet another embodiment, the stirrups 10 as described in the present application are appropriate for use in a variety of conventional imaging systems, including in magnetic resonance imaging (MRI) environments. In a further embodiment, the stirrups 10 may be comprised mostly or entirely of material which is non-magnetic, such as aluminum, brass, or selected grades of steel, or other suitable materials known to one having ordinary skill in the art. In yet a further embodiment, the stirrups 10 may be further comprised mostly or entirely of material which is non-magnetic, non-conductive, and non-metallic, such as a polymer, a reinforced polymer, a fiber reinforced composite material, or other such material known to one having ordinary skill in the art.

[0042] In still another embodiment and with reference to Figure 8, the stirrups 2000 as described in the present application includes a clamp 2410 integrally formed as a single body of unitary construction with accessory rails, such as those typically found on opposite sides of various patient support modalities, enabling each stirrup 2000 to be secured to the appropriate patient support modality. This desirably reduces the number of separate components for manufacture, assembly, or use. In this configuration, the stirrups 2000 resolve the above-described dimensional clearance issues in an additional or optional way relative to the embodiment in which the stirrups 10 comprise at least one post and at least one clamp. Still further, in this configuration, the stirrups 2000 do not exceed the bore diameter of the imaging system bore while maximizing space for the patient's anatomy (which is an additional or optional solution achieved when "the knuckle is coupled to the post on the medial side") and places the knuckle in the anatomically correct location. Additionally or optionally, the stirrups 2000 include an internal wedge mechanism (such as wedge 170 discussed below) to disengage the brake on the knuckle and the wedge mechanism (such as wedge 170 discussed below) that can be increasingly compact and simpler, e.g., which may use a camshaft to actuate the brake of the knuckle, thereby locking or releasing the position of the patient's leg. Thus, the stirrups 10 and 2000 feature an integrated rail clamp for easy attachment and enhanced anatomical access and provide optimal pelvic access while accommodating entry into a bore of an imaging machine, such as a 70cm MR bore. The integrated rail attachment clamp of stirrup 10 and 2000 ensures easy setup and prevents the loss of separate components common with standard stirrups. Further, the handle of stirrup 10 and 2000 facilitates adjustment with minimal effort. Still further, the stirrups 10 and 2000 can be made to be 20% lighter as comparted to conventional stirrups. Moreover, the stirrup 10 and 2000 provides a comfortable boot design for easy cleaning. Finally, the stirrup 10 and 2000 can weigh up to approximately 10 lbs; is configured to support a patient weight limit of up to 500 lbs; and is compatible with various types of imaging machines (e.g., MR Conditional up to 3T, CT compatible).

[0043] A second embodiment of an apparatus, such as a stirrup 1000 for supporting a limb of a patient during imaging and treatment procedures is illustrated in Figures 9- 14B. The apparatus 1000 is configured to provide access to a pelvic region of the patient and to enter a bore of a magnetic resonance imaging scanner.

[0044] In general, the apparatus 1000 has an extension, such as an actuator 120 of an actuator handle assembly and tube subassembly 100; a limb support, such as a boot subassembly 200, coupled to the extension; a clamp, such as integrated rail clamp 410, configured for attachment to a rail at a lateral side of a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner; a knuckle, such as a clamp knuckle subassembly 300, coupled to the extension and to the clamp; and a handle, such as an actuator handle assembly 130. In addition, the clamp 410 has a rail mounting portion configured for attachment to the rail of the patient support and a knuckle mounting portion coupled to the knuckle such that the knuckle is positioned above the rail of the patient support and laterally inward toward the patient when the clamp is attached to the rail of the patient support. Further, an overall width of the patient support and the apparatus with the clamp 410 attached to the rail of the patient support does not exceed a dimension of the bore of the magnetic resonance imaging scanner. Still further, the apparatus 1000 is compatible for use within the bore of the magnetic resonance imaging scanner and during operation of the magnetic resonance imaging scanner for imaging and treatment procedures.

[0045] In an exemplary embodiment, a pair of stirrups 1000 is configured to position limbs of a patient in a lithotomy position, and further configured to minimize collision with imaging and treatment machines. Each stirrup 1000 includes at least one extension, such as an actuator handle assembly and tube subassembly 100, having a first, distal end 124 and a second, proximal end 122 and at least one limb support, such as boot subassembly 200, configured to support a patient's limb coupled to the at first, distal end 124 of the at least one extension 100. A knuckle, such as clamp knuckle subassembly 300, is coupled to the second, proximal end 122 of the at least one extension 100. The knuckle 300 is configured to enable movement of the at least one extension 100 in a spherical motion and includes a brake, such as a pair of bearings 320, configured to limit the movement of the at least one extension 100. A handle, such as actuator handle assembly 130, is located on the first, distal end 122 of the at least one extension 100 and further coupled to the brake 320 of the knuckle 300. The handle 130 is configured to actuate the brake of the knuckle 300, thereby locking or releasing a position of the patient's limb. A post, having a lateral side and a medial side, wherein the knuckle is coupled to the post on the medial side. The stirrups 1000 are further configured to attach to opposing lateral sides of a patient support configured to fit within the bore of an imaging system having a bore diameter, such that the overall width of the patient support with the stirrups 1000 attached does not exceed the width of the patient support without the stirrups 1000 attached, and wherein the overall width of the patient support with the stirrups 1000 attached does not exceed the bore diameter of the imaging system bore. In some aspects, each stirrup 1000 has a structure, such as shock subassembly 400, configured to act as a counterweight to the patient's limb, and is attached to the post on the medial side relatively above the knuckle 300 and attached to the extension 100. In still other aspects, the structure 400 configured to act as a counterweight to the patient's limb is selected from at least one of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return. In certain aspects, the structure 400 configured to act as a counterweight to the patient's limb includes a compression shock. In still other aspects, stirrups 1000 are composed of materials compatible with MR and X-ray imaging environments. Finally, the handle 130 is coupled to a cable connected to the brake 320 of the knuckle 300.

[0046] In still another exemplary embodiment, the apparatus or stirrup 1000 includes an actuator handle assembly and tube subassembly 100, a boot subassembly 200 mounted on the actuator handle assembly and tube subassembly 100, a clamp knuckle subassembly 300 as well as a shock subassembly 400 configured to couple the stirrup 1000 to a frame, such as a rail at a lateral side of a patient support or patient support surface, such as a surgical or patient table (not shown) or a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner.

[0047] FIG. 9 is a front perspective view of a stirrup 1000. In an exemplary embodiment, the stirrup 1000 is configured to support a patient's foot and leg in a plurality of positions. In a non-limiting example, the stirrup 1000 is configured to position the legs of a patient in a lithotomy position, in which one skilled in the art would understand means a surgical and examination position where the patient lies supine (on their back) with their legs flexed, abducted (separated), and supported in stirrups, such as a pair of stirrups 100. To facilitate this position, the stirrup 1000 is configured to be coupled to (a rail of) a patient support surface and is configured to stabilize or immobilize one or more of patient's foot and leg in a certain position during a medical procedure. In an exemplary embodiment, the stirrup 1000 is for use with a patient support surface for use with (1) diagnostic imaging machines, such as computed tomography (CT), magnetic resonance imaging (MR), and positron emission tomography (PET), (2) an operating table, (3) a hospital bed, an operating room (OR) table, a treatment machine, robotic surgical arms, and the like.

[0048] Turning now to FIG. 10A, the stirrup 1000 includes an actuator handle assembly and tube subassembly 100 with a boot subassembly 200 mounted thereon. The stirrup also includes a clamp knuckle subassembly 300 as well as a shock subassembly 400, which together are configured to couple the stirrup 1000 to a frame including a rail of a patient support surface, such as a surgical or patient table (not shown) or patient support use with a magnetic resonance imaging scanner.

[0049] FIG. 11 shows an exploded view of the limb support or boot subassembly 200. In an exemplary embodiment, the boot subassembly 200 includes a mounting surface 210 configured to couple or mount a boot 220 to a portion of the stirrup 1000, such as the actuator handle assembly and tube subassembly 100, or more particularly, a distal end portion 124 of the extension 120 of the actuator handle assembly and tube subassembly 100 (discussed below). The boot 220 is mounted to the mounting surface 210 via known attachment mechanisms, such as fasteners 260 (e.g., a plurality of flanged button head screws). One skilled in the art would understand from the description herein that the boot 220 is not limited to the size and shape shown in the figure, but rather the design and geometry of the boot 220 may be sized to accommodate a specific individual patient or a spectrum of patients having physiological measurements within expected ranges of values. At least the boot 220 is coupled to the actuator handle assembly and tube subassembly 100 or components thereof for movement about one or more axes relative to the actuator handle assembly and tube subassembly 100. The attachment between at least the boot 220 and the actuator handle assembly and tube assembly 100 as well as movement of at least the boot 220 relative the actuator handle assembly and tube assembly 100, is provided or facilitated by interaction among a boot clamp 230, a rod 232, a ball bearing 234, a tension rod 236, and a knob 238 (e.g., a tri-lobe knob), all of which are attached to each other and the mounting surface 210, via known attachment mechanisms, such as fasteners 260 (e.g., a set screw), dowel pins 262, and the like. A plug 240 as well as washers 270 are also provided. Additionally or optionally, visible indicia 250 indicating a type of boot 220 (e.g., for a left or right foot) may be affixed to one or more components of the boot subassembly 200, such as a surface of boot 220. Additionally or optionally, a boot padding 280 (FIG. 10A) may be provided and releasably coupled to the boot 220 for patient comfort.

[0050] Referring now to FIGS. 12A-12H, the stirrup 1000 includes an actuator handle assembly and tube subassembly 100. As shown in FIG. 12A, the actuator handle assembly and tube subassembly 100 includes a tube 110 extending along a longitudinal axis (A). Disposed within the tube 110 is an actuator 120, such as a release rod or extension, extending parallel to the longitudinal axis A between a proximal end or end portion 122 and a distal end or end portion 124 opposite the proximal end 122. The proximal end 122 includes an actuator handle assembly 130, the components of which are best illustrated in FIGS. 12B-12F. Thus, the extension includes an actuator 120 that is movable relative to the brake 320 of the knuckle 300, and the handle 130 has a trigger, such as release trigger 150, for moving the actuator 120 relative to the brake 320 of the knuckle 300. In some aspects, the handle or actuator handle assembly 130 is located at the distal end portion 124 of the extension 120 and coupled to the brake 320 of the knuckle 300, the handle being configured to selectively actuate the brake 320 of the knuckle 300 to limit the spherical movement of at least extension 120 relative to the clamp 300. As illustrated in FIGS. 12G-12H, the distal end 124 is configured to interact with a clamp knuckle subassembly 300, discussed further below and illustrated in FIGS. 13A-13D.

[0051] Turning now to FIG. 12B, the actuator handle assembly 130 includes a release handle 140 coupled to a release trigger 150 configured to move (e.g., pivot) relative to the release handle 132. A sleeve bearing 136 is provided to facilitate the motion between of release trigger 150 relative to the release handle 140. A plurality of attachment means known to one skilled in the art, such as fasteners 160 (e.g., a set screw, a stainless steel polished thumb screw, a shoulder screw, etc.), and a hex nut 162 are provided to couple the components together and to one or more components of at least the actuator handle assembly and tube subassembly 100. In an exemplary embodiment, the size and overall geometry of the actuator handle assembly 130 provides a compact profile, which advantageously permits accommodation of the stirrup 1000 within a bore of an imaging machine, for example. In one non-limiting example, the inventors found that the size and shape of the release trigger 150 provides a user with an ergonomic grip, such that actuation or release of the release trigger 150 permits or restrict the clamp knuckle subassembly 300 to adjust between latched and unlatched states and therefore place the stirrups 1000 in a desired position (discussed further below).

[0052] Turning now to FIGS. 12C-12F, in an exemplary embodiment of an operation of the actuator handle assembly 130, the release trigger 150 of the actuator handle assembly 130 is coupled to the actuator 120, such that a user is configured to squeeze or release the release trigger 150 to permit or restrict the clamp knuckle subassembly 300 coupled (via the actuator 120) to move between latched and unlatched states. In an exemplary embodiment, as shown in FIGS. 12D-12F, the release trigger 150 is movable (e.g., pivotable) relative to the release handle 140 around a rotation axis (C) that is transverse to a translation direction (B) of the actuator 120 (discussed below). Additionally or optionally, the release trigger 150 is movable (e.g., pivotable) relative to the release handle 140 between a rest position (FIG. 12E), in which the distal end 124 of the actuator 120 is in a locked or retracted position and the clamp knuckle subassembly 300 is in the locked condition or latched state, thereby restricting or preventing movement of the stirrup 1000 relative to the patient or patient support surface, and an actuated position (FIG. 12F), in which the distal end 124 of the actuator 120 is in an unlocked or advanced position and the clamp knuckle subassembly 300 is in the unlocked condition or unlatched state, thereby permitting movement of the stirrup 1000 relative to the patient or patient support surface.

[0053] When the release trigger 150 is in the rest position, the position of the stirrup 1000 supporting one or more of the lower extremities of the patient is stable, such that movement of the stirrup 1000 is limited or prevented relative to the patient or the patient support surface is stable or immobilized. In an exemplary embodiment, in a rest position (FIG. 12E), the release trigger 134 is positioned to avoid contact with an inner surface 142 of the release handle 140. In a non-limiting example, an elongate member 152 of the release trigger 150 is positioned obliquely at an angle of X° relative to inner surface 142 of the release handle 140, such that the release trigger 150 is positioned a distance away from the inner surface 142 of the release trigger 150.

[0054] Conversely, a user may actuate (e.g., squeeze) the release trigger 150 around the rotation axis (C) toward the actuated position (FIG. 12F). In an exemplary embodiment, actuating the release trigger 150 around the rotation axis (C) toward the actuated position decreases the distance between the inner surface 142 and the release trigger 150 until the release trigger 150 is substantially in contact with the inner surface 142 of the release handle 140. Additionally or optionally, actuating the trigger or elongate member 152 around the rotation axis (C) causes a cam having a surface 154, with the trigger 152 being coupled to the cam having surface 154 (e.g., the cam having surface 154 is fixed to trigger 152 for movement with the trigger 152), to interact (e.g., actuate, push or pull, etc.) with a rod or plunger (FIGS. 12E-12F) located at the proximal end 122 of the actuator 120, such that the actuator 120 moves along the translation direction B between the locked and unlocked positions. In this way, the distal end 124 of the actuator 120 interacts with one or more components of the clamp knuckle subassembly 300 such that the clamp knuckle subassembly 300 reaches a latched or unlatched state.

[0055] Referring now to FIGS. 12G and 12H, the distal end 124 of the actuator 120 includes a wedge portion 170. The wedge or wedge portion 170 is coupled for movement relative to a ball clamp 302 / 304 of the knuckle 300 (discussed below) between an advanced position configured to urge the ball clamp 302 / 304 toward the unlocked condition and a retracted position configured to allow the ball clamp 302 / 304 to be in the locked condition. Additionally or optionally, the knuckle 300 includes at least one bearing 320 (discussed below) positioned for contact with the wedge 170 as the wedge 170 moves relative to the ball clamp 302 / 304. In general, unlike conventional stirrups which utilize a rotating camshaft to open a socket for operation, the wedge portion 170 provides a more compact design and lower profile, thereby providing more space for patient anatomy, such as during an imaging procedure, in which portions of the pair of stirrups 1000 critical to adjusting and maintaining the position of the patient's anatomy (e.g., the shock subassembly 400 and clamp knuckle subassembly 300) are located within boundaries defined the patient support surface, and thus within a maximum width of a bore (having a fixed bore diameter or arc radius) of an MRI or CT scanner (e.g., as shown in FIGS. 6A-6B). Advantageously, this configuration of the inventive stirrups 1000 minimizes or eliminates the need to position and reposition the patient in the course of procedures where space is constrained, such as in imaging environments and machines which are typically designed to accommodate the width of the patient support surface included with the imaging machine with little to no room for overage. In an exemplary operation discussed in further detail below, unlike conventional stirrups which use a shaft or cable to rotate a camshaft, the wedge portion 170 is attached to a shaft (e.g., actuator 120 or distal end 124 of actuator 120) that actuates to move the wedge portion 170 between the at least one pair of ball bearings 320, thereby opening the socket clamp 302, 304 or separating respective surfaces of the clamp 304 and clamp 302 from substantially contacting each other.

[0056] In an exemplary embodiment, as shown in FIG. 12H, the wedge 170 having a contact surface, such as first ramp 172 or a second ramp 174, oriented at an angle (e.g., x°) with respect to an axis of movement of the wedge 170 (e.g., along translation direction B) relative to the ball clamp 302 / 304. In some aspects, the wedge 170 has plural surface portions having different angles (e.g., x°) with respect to the axis of the movement of the wedge 170 relative to the ball clamp 302 / 304. In a nonlimiting example, the wedge portion 170 includes one or more ramped surfaces, such as first ramp 172 and a second ramp 174. As shown in FIG. 12H, in an exemplary embodiment, a relatively distal surface portion, such as first ramp 172, of the plurality of surface portions of the wedge 170 has a larger angle with respect to the axis of the movement of the wedge 170 relative to the ball clamp 302 / 304, and a relatively proximal surface portion 174 of the plurality of surface portions of the wedge 170 has a smaller angle with respect to the axis of the movement of the wedge 170 relative to the ball clamp 302 / 304. Advantageously, in this configuration, the relatively distal surface 172 requires a higher pressure or force to move the wedge 170 toward the advanced position, and the relatively proximal surface 174 requires a lower force to move the wedge 170 toward the advanced position or to retain the wedge 170 in the advanced position. Additionally or optionally, a guide 180 fastened to the rod 120 with a fastener 182 is provided. The guide 180 may provide feedback to the user that the actuator 120 has reached one of the unlocked and locked positions and / or the clamp knuckle subassembly 300 has reached one of the unlatched and latched states. Additionally or optionally, the wedge 170 and the distal end 124 of the actuator 120 may be integrally formed as a single body of unitary construction. Alternatively, the wedge 170 may be a separate component and is thus configured to be coupled to the distal end 124 of the actuator 120 via known attachment means, such as a fastener 184 (e.g., spring pin).

[0057] Turning now to FIGS. 10A-10C and 13A-13F, an exemplary embodiment of the clamp knuckle subassembly 300 is provided. In some aspects, the knuckle, such as clamp knuckle subassembly 300, is coupled to the proximal end portion 122 of the extension 100 and to the clamp 300. The knuckle 300 is configured to enable spherical movement of at least the extension 120 relative to the clamp 300, and the knuckle 300 has a brake (such as a pair of bearings 320) configured to limit the spherical movement of the extension 120 relative to the clamp 300. The clamp knuckle subassembly 300 is configured to interact with one or more components of stirrup 1000, such as actuator handle assembly 130 and the actuator handle assembly and tube subassembly 100. In an exemplary embodiment, as shown in FIGS. 10A and 10C, the clamp knuckle subassembly 300 is attached to the actuator handle assembly and tube subassembly 100 via a clamp 340 and fasteners 306 (e.g., socket head cap screw (SHCS) screw, set screw, etc.). Additionally or optionally, as shown in FIG. 10A, the clamp knuckle subassembly 300 is positioned under or within a knuckle cover 350 via fasteners 306 (e.g., flanged button head screw), thereby providing protection for at least the components of the clamp knuckle subassembly 300.

[0058] As shown in FIG. 13A, clamp knuckle subassembly 300 includes a fixed stirrup clamp 302 and a moving stirrup clamp 304, with together define a cavity of space for housing one or more components of the clamp knuckle subassembly 300, such as a knuckle 300 comprising stirrup ball 310 and at least one pair of ball bearings 320. In a non-limiting example, the knuckle 300 comprising the ball 310 and the ball clamp 302 / 304 is configured for movement between a locked condition or latched state, in which the ball clamp 302 / 304 resists or prevents rotation of the ball 310 relative to the ball clamp 302 / 304 and an unlocked condition or unlatched state in which the ball clamp 302 / 304 permits rotation of the ball 310 relative to the ball clamp 302 / 304. Additionally or optionally, the ball clamp 302 / 304 of the knuckle 300 is biased toward the locked condition. To achieve this, a spring 330, such a spring having at least one washer 332, is positioned to bias the ball clamp 302 / 304 toward the locked condition. In an exemplary embodiment, the moving stirrup clamp 304 is movable relative to the fixed stirrup clamp 302 (e.g., for adjustment or movement of the stirrup 1000 relative to the patient or patient support surface) when the clamp knuckle subassembly 300 is in the unlatched state. Although the fixed stirrup clamp 302 and the moving stirrup clamp 304 are illustrated as being comprised of separate components, one of ordinary skill in the art would understand from the description herein that the fixed stirrup clamp 302 and the moving stirrup clamp 304 may be integrally formed as a single body of unitary construction. Additionally or optionally, the one or more components of the clamp knuckle subassembly 300 are affixed to one another and one or more components of the stirrup 1000 via known attachment means or mechanisms, such as fasteners 306 (e.g., shoulder screw, SHCS screw, bolt, etc.) and alignment features 308 (e.g., dowel pin). Additionally or optionally, a biasing means 330 is provided to bias the clamp knuckle subassembly 300 toward the latched state. In a non-limiting example, the biasing means 330 includes a Belleville disk having multiple conical washers 332 having elastic properties that are stacked in an alternating arrangement of types of washers (e.g., concave up and concave down, etc.).

[0059] In operation, clamp knuckle subassembly 300 facilitates a spherical or orbital motion of at least the boot subassembly 200 mounted on the hand and tube subassembly 100, such that the angular and rotational position of the stirrup 1000 better simulates the range of motion of a typical patient's hip joint. Typically, this range is up to approximately 30 degrees in a lateral motion and up to approximately 10 degrees in a medial motion. The clamp knuckle subassembly 300 is configured such that it enables spherical or orbital motion of the actuator 120 (on which the boot subassembly 200 is mounted). This spherical motion allows the stirrup 1000 to rotate, abduct, and / or adduct the patient's lower extremities to suitably position the patient for their imaging or treatment procedure. Features may additionally be provided on each stirrup to independently lock each stirrup 1000 in place at a desired angular or rotational position.

[0060] In an exemplary embodiment, as best shown in FIGS. 13B-13F, interaction among the release trigger 150 of the actuator handle assembly 130, the distal end 124 of the actuator 120 having the wedge 170, and the at least one pair of ball bearings 320 of the clamp knuckle subassembly 300 permits or restriction adjustment of the stirrup 1000 in order to achieve a desired angular or rotational position of the patient's lower extremities relative to the patient support surface. Thus, in operation, as best shown in FIG. 13E, a user actuates the release trigger 150 of the actuator handle assembly 130 as described above, thereby causing the actuator 120 to move along the translation direction B toward the unlocked position, in which the first ramp 172 is driven (e.g., by actuation of the actuator 120) between the at least one pair of ball bearings 320 to release the stirrup ball 310 stirrup clamps 302, 304. In this way, the clamp knuckle subassembly 300 is moved toward the unlatched state, in which adjustment of the position of the stirrup 1000 relative to the patient support surface or the patient is permitted. In response to further actuation of the release trigger 150 of the actuator handle assembly 130 (e.g., by the user), as best shown in FIG. 13F, the second ramp 174 is moved further between the at least one pair of ball bearings 320, thereby desirably requiring lesser grip strength to maintain the clamp knuckle subassembly 300 in the unlatched state as the position of the stirrup 1000 relative to the patient support surface or the patient is adjusted (e.g., by the user).

[0061] Referring now to FIGS. 10B-10C, 13C, and 14A-14B, stirrup 1000 includes a shock subassembly 400. In an exemplary embodiment, the shock subassembly 400 is coupled to one or more components of the stirrup 1000, such as the clamp knuckle subassembly 300, via known attachment mechanisms such as fastener 402 (e.g., flat head socket cap (FHS) screw) and alignment features such as dowel pin 404. Turning now to FIGS. 14A-14B, the shock subassembly 400 includes an integrated rail clamp 410 configured to be attached to one or more components of the clamp knuckle subassembly 300 (as shown in FIGS. 10A-10B), via fasteners 402 (e.g., SH shoulder screw, set screw, etc.).

[0062] In a non-limiting example, the integrated rail clamp 410 is configured for attachment to a rail at a lateral side of a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner. Additionally or optionally, the clamp 410 has a rail mounting portion 412 configured for attachment to the rail of the patient support and a knuckle mounting portion 414 coupled to the knuckle 300, the knuckle mounting portion 414 being configured such that the knuckle 300 is positioned above the rail of the patient support and laterally inward toward the patient when the clamp 410 is attached to the rail of the patient support. The knuckle mounting portion 414 of the clamp 410 and the rail mounting portion 412 of the clamp 410 together define a recess into which the knuckle 300 extends, such that the knuckle 300 is positioned above the rail of the patient support and laterally inward toward the patient when the clamp 410 is attached to the rail of the patient support. Additionally or optionally, the rail mounting portion 412 of the clamp 410 cannot be removed from the knuckle mounting portion 414 of the clamp when the clamp 410 is detached from the rail of the patient support during intended usage of the apparatus 1000 before, during, or after an imaging or treatment procedure.

[0063] Additionally or optionally, the clamp 410 has an integral construction wherein the rail mounting portion 412 configured for attachment to the rail of the patient support is integral with the knuckle mounting portion 414 coupled to the knuckle 300. In this way, an overall width of the patient support and the apparatus 1000 with the clamp 410 attached to the rail of the patient support does not exceed a dimension of the bore of the magnetic resonance imaging scanner. Thus, unlike conventional stirrups which have a separate clamp and blade style attachment (which limits movement within a bore of an imaging machine, for example), the shock subassembly 400 provides a more compact design, thereby providing more space for patient anatomy, such as during an imaging procedure, in which portions of the pair of stirrups 1000 critical to adjusting and maintaining the position of the patient's anatomy are located within boundaries defined the patient support surface, and thus within a maximum width of a bore (having a fixed bore diameter or arc radius) of an MR.I or CT scanner. Advantageously, this configuration of the inventive stirrups 1000 maximizes space for patient anatomy and desirably prevents loss of separate pieces or components of stirrup 1000 (because via the integrated rail clamp 410, the shock subassembly 400 can be moved or travel with the other components of the stirrup 1000).

[0064] In an exemplary embodiment, the apparatus 1000 includes an extension support, such as the shock subassembly 400, coupled to the extension 120 and to the clamp 410. The extension support 400 is configured to supplement support to the extension 120 when weight of the limb of a patient is applied to the apparatus 1000. Additionally or optionally, the extension support 400 includes one or more of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return.

[0065] In a non-limiting example, the shock subassembly 400 includes a telescoping strut 420 as configured to counteract the weight of at least the boot 220 and the patient's lower extremities (e.g., leg and foot) supported by the boot 220. As such, when the clamp knuckle subassembly 300 is in the unlatched state, the telescoping strut 220 provides a counterweight force sufficient to support at least a portion of a weight of at least the boot 220 and the patient's lower extremities (e.g., leg and foot) supported by the boot 220, thereby assisting a user (e.g., medical personnel, etc.) in positioning and repositioning the patient's lower extremities via the stirrup 1000. In an exemplary embodiment, the telescoping strut 420 has a counterbalance gas spring 422 that is pre-charged with gas to provide positioning assistance. Additionally or alternatively, the telescoping strut 420 may be a hydraulic or pneumatic cylinder, a linear actuator, an un-powered strut, or a combination thereof. In an exemplary embodiment, the telescoping strut 420 extends between a proximal end 426 and a distal end 428 along a direction parallel to longitudinal axis A. The apparatus 1000 includes conductive components that would, if directly connected, at least partially form a conductive circuit. In an exemplary, embodiment, the actuator 120, knuckle 300, and the shock subassembly 400 d may form a conductive loop, which is undesirable during certain procedures, such as an MRI procedure. Thus, in an exemplary embodiment, at least one non-conductive barrier is interposed between the conductive components of the apparatus 1000 to prevent the formation of the conductive circuit, thereby reducing the generation of heat in the apparatus 1000 by operation of the magnetic resonance imaging scanner during imaging and treatment procedures. Additionally or optionally, the non-conductive barrier is interposed between the extension support 400 and the clamp 300.

[0066] In a non-limiting example, at the proximal end 426 is located a hinge 430, sleeve bearing 432, and pivot end 434 of a piston rod telescopically received within a tube. The one or more components located at the proximal end 426 of the strut 420 includes components being made of non-conductive material, thereby isolating the metal loop created by other components of the stirrup 1000 (e.g., the hand and tube subassembly 100, clamp knuckle subassembly 300, etc.), thereby minimizing or eliminating a possibility of a patient being injured due to heating of components of stirrup 1000 during an imaging procedures (e.g., an MRI Process) when the patient anatomy is in contact with components of the stirrup 1000. Thus, the non-metallic material of components located at the proximal end 426 of the strut 420 advantageously provides an isolation of electrical or radio frequency (RF) conductivity. Further, the proximal end 426 is coupled to the integrated rail clamp 410 via fastener 402 (e.g., SH shoulder) and aluminum spacer 406. At the distal end 428 is a ball joint 424 configured to be coupled to a tube mount 112 (FIG. 12A), which is fixed to the tube 110 of the hand and tube subassembly 100 via fastener 102 (e.g., set screw). A knob 438 (e.g., a tri-lobe knob) is provided and rotation of the knob 438 (or a handle) permits the user to open and close the clamp 410 (e.g., for attachment to a rail or frame of the patient support surface).

[0067] Various aspects of embodiments of the invention are described below.

[0068] Aspect 1. An apparatus for supporting a limb of a patient during imaging and treatment procedures, the apparatus being configured to provide access to a pelvic region of the patient and to enter a bore of a magnetic resonance imaging scanner, the apparatus comprising : an extension having a distal end portion and a proximal end portion; a limb support coupled to the distal end portion of the extension; a clamp configured for attachment to a rail at a lateral side of a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner; a knuckle coupled to the proximal end portion of the extension and to the clamp, the knuckle being configured to enable spherical movement of the extension relative to the clamp, and the knuckle having a brake configured to limit the spherical movement of the extension relative to the clamp; and a handle located at the distal end portion of the extension and coupled to the brake of the knuckle, the handle being configured to selectively actuate the brake of the knuckle to limit the spherical movement of the extension relative to the clamp; wherein the clamp has a rail mounting portion configured for attachment to the rail of the patient support and a knuckle mounting portion coupled to the knuckle, the knuckle mounting portion being configured such that the knuckle is positioned laterally inward toward the rail of the patient support when the clamp is attached to the rail of the patient support; wherein an overall width of the patient support and the apparatus with the clamp attached to the rail of the patient support does not exceed a dimension of the bore of the magnetic resonance imaging scanner; and wherein the apparatus is compatible for use within the bore of the magnetic resonance imaging scanner and during operation of the magnetic resonance imaging scanner for imaging and treatment procedures.

[0069] Aspect 2. The apparatus of aspect 1, further comprising an extension support coupled to the extension and to the clamp, the extension support being configured to supplement support to the extension when weight of the limb of a patient is applied to the apparatus.

[0070] Aspect 3. The apparatus of aspect 2, the extension support including one or more of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return.

[0071] Aspect 4. A system for supporting limbs of a patient during imaging and treatment procedures, the system comprising a pair of apparatus according to aspect 1.

[0072] Aspect 5. A system for supporting a patient during imaging and treatment procedures, the system comprising a pair of apparatus according to aspect 1 attached to the patient support.

[0073] CAM OF HANDLE

[0074] Aspect 6. The apparatus of aspect 1, the extension comprising an actuator movable relative to the brake of the knuckle, and the handle comprising a trigger for moving the actuator relative to the brake of the knuckle. Aspect 7. The apparatus of aspect 6, the actuator comprising a rod or a plunger.

[0075] Aspect 8. The apparatus of aspect 7, the extension comprising a tube surrounding the rod or the plunger.

[0076] Aspect 9. The apparatus of aspect 6, the trigger being coupled to a cam having a surface configured to cause movement of the actuator relative to the brake of the knuckle upon movement of the trigger.

[0077] Aspect 10. The apparatus of aspect 9, the cam being fixed to the trigger for movement with the trigger.

[0078] WEDGE OF KNUCKLE'S BRAKE

[0079] Aspect 11. The apparatus of aspect 1, the knuckle comprising a ball and a ball clamp configured for movement between a locked condition in which the ball clamp resists or prevents rotation of the ball relative to the ball clamp and an unlocked condition in which the ball clamp permits rotation of the ball relative to the ball clamp.

[0080] Aspect 12. The apparatus of aspect 11, the ball clamp of the knuckle being biased toward the locked condition.

[0081] Aspect 13. The apparatus of aspect 12, the knuckle comprising a spring positioned to bias the ball clamp toward the locked condition.

[0082] Aspect 14. The apparatus of aspect 13, the spring comprising at least one spring washer.

[0083] Aspect 15. The apparatus of aspect 11, further comprising a wedge coupled for movement relative to the ball clamp of the knuckle between an advanced position configured to urge the ball clamp toward the unlocked condition and a retracted position configured to allow the ball clamp to be in the locked condition.

[0084] Aspect 16. The apparatus of aspect 15, the knuckle comprising at least one bearing positioned for contact with the wedge as the wedge moves relative to the ball clamp.

[0085] Aspect 17. The apparatus of aspect 11, the wedge having a contact surface oriented at an angle with respect to an axis of movement of the wedge relative to the ball clamp.

[0086] Aspect 18. The apparatus of aspect 17, the contact surface of the wedge having plural surface portions having different angles with respect to the axis of the movement of the wedge relative to the ball clamp.

[0087] Aspect 19. The apparatus of aspect 18, wherein a relatively distal surface portion of the plurality of surface portions of the wedge has a larger angle with respect to the axis of the movement of the wedge relative to the ball clamp, and a relatively proximal surface portion of the plurality of surface portions of the wedge has a smaller angle with respect to the axis of the movement of the wedge relative to the ball clamp, the relatively distal surface requiring a higher force to move the wedge toward the advanced position, and the relatively proximal surface requiring a lower force to move the wedge toward the advanced position or to retain the wedge in the advanced position.

[0088] INTEGRATED RAIL CLAMP

[0089] Aspect 20. The apparatus of aspect 1, the clamp having an integral construction wherein the rail mounting portion configured for attachment to the rail of the patient support is integral with the knuckle mounting portion coupled to the knuckle.

[0090] Aspect 21. The apparatus of aspect 20, wherein the knuckle mounting portion of the clamp and the rail mounting portion of the clamp together define a recess into which the knuckle extends, such that the knuckle is positioned laterally inward toward the rail of the patient support when the clamp is attached to the rail of the patient support.

[0091] Aspect 22. The apparatus of aspect 20, wherein the rail mounting portion of the clamp cannot be removed from the knuckle mounting portion of the clamp when the clamp is detached from the rail of the patient support during intended usage of the apparatus before, during, or after an imaging or treatment procedure.

[0092] NON-CONDUCTIVE COMPONENT

[0093] Aspect 23. The apparatus of aspect 1, further comprising conductive components that would, if directly connected, at least partially form a conductive circuit.

[0094] Aspect 24. The apparatus of aspect 23, further comprising at least one non- conductive barrier interposed between the conductive components of the apparatus to prevent the formation of the conductive circuit, thereby reducing the generation of heat in the apparatus by operation of the magnetic resonance imaging scanner during imaging and treatment procedures.

[0095] Aspect 25. The apparatus of aspect 24, the conductive components including the extension and an extension support coupled to the extension and to the clamp, the non-conductive barrier being interposed between the extension support and the clamp.

[0096] Aspect 26. A pair of stirrups configured to position limbs of a patient in a lithotomy position, and further configured to minimize collision with imaging and treatment machines, each stirrup in the pair comprising: at least one extension, having a first, distal end and a second, proximal end; at least one limb support, configured to support a patient's limb coupled to the at first, distal end of the at least one extension; a knuckle, coupled to the second, proximal end of the at least one extension, and configured to enable movement of the at least one extension in a spherical motion, further having a brake configured to limit the movement of the at least one extension; a handle, located on the first, distal end of the at least one extension and further coupled to the brake of the knuckle, and configured to actuate the brake of the knuckle, thereby locking or releasing a position of the patient's limb; and a post, having a lateral side and a medial side, wherein the knuckle is coupled to the post on the medial side, wherein the stirrups are further configured to attach to opposing lateral sides of a patient support configured to fit within the bore of an imaging system having a bore diameter, wherein the overall width of the patient support with the stirrups attached does not exceed the width of the patient support without the stirrups attached, and wherein the overall width of the patient support with the stirrups attached does not exceed the bore diameter of the imaging system bore.

[0097] Aspect 27. The pair of stirrups of aspect 26, wherein each stirrup further comprises a structure configured to act as a counterweight to the patient's limb, attached to the post on the medial side relatively above the knuckle and attached to the extension.

[0098] Aspect 28. The pair of stirrups of aspect 27, wherein the structure configured to act as a counterweight to the patient's limb is selected from at least one of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return.

[0099] Aspect 29. The pair of stirrups of aspect 28, wherein the structure configured to act as a counterweight to the patient's limb includes a compression shock.

[0100] Aspect 30. The pair of stirrups of aspect 26, wherein the stirrups are composed of materials compatible with MR and X-ray imaging environments.

[0101] Aspect 31. The pair of stirrups of aspect 26, wherein the handle is coupled to a cable connected to the brake of the knuckle.

[0102] While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Additionally, variations, changes and substitutions among the different embodiments discussed above may fall within the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention

Claims

What is claimed :

1. An apparatus for supporting a limb of a patient during imaging and treatment procedures, the apparatus being configured to provide access to a pelvic region of the patient and to enter a bore of a magnetic resonance imaging scanner, the apparatus comprising : an extension having a distal end portion and a proximal end portion; a limb support coupled to the distal end portion of the extension; a clamp configured for attachment to a rail at a lateral side of a patient support that is sized to fit within the bore of the magnetic resonance imaging scanner; a knuckle coupled to the proximal end portion of the extension and to the clamp, the knuckle being configured to enable spherical movement of the extension relative to the clamp, and the knuckle having a brake configured to limit the spherical movement of the extension relative to the clamp; and a handle located at the distal end portion of the extension and coupled to the brake of the knuckle, the handle being configured to selectively actuate the brake of the knuckle to limit the spherical movement of the extension relative to the clamp; wherein the clamp has a rail mounting portion configured for attachment to the rail of the patient support and a knuckle mounting portion coupled to the knuckle, the knuckle mounting portion being configured such that the knuckle is positioned laterally inward toward the rail of the patient support when the clamp is attached to the rail of the patient support; wherein an overall width of the patient support and the apparatus with the clamp attached to the rail of the patient support does not exceed a dimension of the bore of the magnetic resonance imaging scanner; and wherein the apparatus is compatible for use within the bore of the magnetic resonance imaging scanner and during operation of the magnetic resonance imaging scanner for imaging and treatment procedures.

2. The apparatus of claim 1, further comprising an extension support coupled to the extension and to the clamp, the extension support being configured to supplement support to the extension when weight of the limb of a patient is applied to the apparatus.

3. The apparatus of claim 2, the extension support including one or more of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return.

4. A system for supporting limbs of a patient during imaging and treatment procedures, the system comprising a pair of apparatus according to claim 1.

5. A system for supporting a patient during imaging and treatment procedures, the system comprising a pair of apparatus according to claim 1 attached to the patient support.

6. The apparatus of claim 1, the extension comprising an actuator movable relative to the brake of the knuckle, and the handle comprising a trigger for moving the actuator relative to the brake of the knuckle.

7. The apparatus of claim 6, the actuator comprising a rod or a plunger.

8. The apparatus of claim 7, the extension comprising a tube surrounding the rod or the plunger.

9. The apparatus of claim 6, the trigger being coupled to a cam having a surface configured to cause movement of the actuator relative to the brake of the knuckle upon movement of the trigger.

10. The apparatus of claim 9, the cam being fixed to the trigger for movement with the trigger.

11. The apparatus of claim 1, the knuckle comprising a ball and a ball clamp configured for movement between a locked condition in which the ball clamp resists or prevents rotation of the ball relative to the ball clamp and an unlocked condition in which the ball clamp permits rotation of the ball relative to the ball clamp.

12. The apparatus of claim 11, the ball clamp of the knuckle being biased toward the locked condition.

13. The apparatus of claim 12, the knuckle comprising a spring positioned to bias the ball clamp toward the locked condition.

14. The apparatus of claim 13, the spring comprising at least one spring washer.

15. The apparatus of claim 11, further comprising a wedge coupled for movement relative to the ball clamp of the knuckle between an advanced position configured to urge the ball clamp toward the unlocked condition and a retracted position configured to allow the ball clamp to be in the locked condition.

16. The apparatus of claim 15, the knuckle comprising at least one bearing positioned for contact with the wedge as the wedge moves relative to the ball clamp.

17. The apparatus of claim 11, the wedge having a contact surface oriented at an angle with respect to an axis of movement of the wedge relative to the ball clamp.

18. The apparatus of claim 17, the contact surface of the wedge having plural surface portions having different angles with respect to the axis of the movement of the wedge relative to the ball clamp.

19. The apparatus of claim 18, wherein a relatively distal surface portion of the plurality of surface portions of the wedge has a larger angle with respect to the axis of the movement of the wedge relative to the ball clamp, and a relatively proximal surface portion of the plurality of surface portions of the wedge has a smaller angle with respect to the axis of the movement of the wedge relative to the ball clamp, the relatively distal surface requiring a higher force to move the wedge toward the advanced position, and the relatively proximal surface requiring a lower force to move the wedge toward the advanced position or to retain the wedge in the advanced position.

20. The apparatus of claim 1, the clamp having an integral construction wherein the rail mounting portion configured for attachment to the rail of the patient support is integral with the knuckle mounting portion coupled to the knuckle.

21. The apparatus of claim 20, wherein the knuckle mounting portion of the clamp and the rail mounting portion of the clamp together define a recess into which the knuckle extends, such that the knuckle is positioned laterally inward toward the rail of the patient support when the clamp is attached to the rail of the patient support.

22. The apparatus of claim 20, wherein the rail mounting portion of the clamp cannot be removed from the knuckle mounting portion of the clamp when the clamp is detached from the rail of the patient support during intended usage of the apparatus before, during, or after an imaging or treatment procedure.

23. The apparatus of claim 1, further comprising conductive components that would, if directly connected, at least partially form a conductive circuit.

24. The apparatus of claim 23, further comprising at least one non-conductive barrier interposed between the conductive components of the apparatus to prevent the formation of the conductive circuit, thereby reducing the generation of heat in the apparatus by operation of the magnetic resonance imaging scanner during imaging and treatment procedures.

25. The apparatus of claim 24, the conductive components including the extension and an extension support coupled to the extension and to the clamp, the non- conductive barrier being interposed between the extension support and the clamp.

26. A pair of stirrups configured to position limbs of a patient in a lithotomy position, and further configured to minimize collision with imaging and treatment machines, each stirrup in the pair comprising : at least one extension, having a first, distal end and a second, proximal end; at least one limb support, configured to support a patient's limb coupled to the at first, distal end of the at least one extension; a knuckle, coupled to the second, proximal end of the at least one extension, and configured to enable movement of the at least one extension in a spherical motion, further having a brake configured to limit the movement of the at least one extension; a handle, located on the first, distal end of the at least one extension and further coupled to the brake of the knuckle, and configured to actuate the brake of the knuckle, thereby locking or releasing a position of the patient's limb; and a post, having a lateral side and a medial side, wherein the knuckle is coupled to the post on the medial side, wherein the stirrups are further configured to attach to opposing lateral sides of a patient support configured to fit within the bore of an imaging system having a bore diameter, wherein the overall width of the patient support with the stirrups attached does not exceed the width of the patient support without the stirrups attached, and wherein the overall width of the patient support with the stirrups attached does not exceed the bore diameter of the imaging system bore.

27. The pair of stirrups of claim 26, wherein each stirrup further comprises a structure configured to act as a counterweight to the patient's limb, attached to the post on the medial side relatively above the knuckle and attached to the extension.

28. The pair of stirrups of claim 27 , wherein the structure configured to act as a counterweight to the patient's limb is selected from at least one of a compression shock, a spring-damper system, a separated damper and spring, a gas strut, and a gas cylinder with a spring assisted return.

29. The pair of stirrups of claim 28, wherein the structure configured to act as a counterweight to the patient's limb includes a compression shock.

30. The pair of stirrups of claim 26, wherein the stirrups are composed of materials compatible with MR and X-ray imaging environments.

31. The pair of stirrups of claim 26, wherein the handle is coupled to a cable connected to the brake of the knuckle.

Images