Patent ID: 12226354

DETAILED DESCRIPTION

In embodiments, a surgical positioning system is used to position parts of a patient, for example, to elevate parts with respect to other parts of the patient to improve access to certain anatomical features during surgery. In some embodiments, the surgical positioning system can be used in hip replacement surgery to elevate the pelvis during some stages of the surgery and to elevate and lateralize the femur during other stages of the surgery. The surgical positioning system can be added to a standard surgical operating table without fixtures or traction elements for positioning the legs of the patient.

FIG.1illustrates generalized features of an exemplary surgical positioning system100for hip replacement surgery. The surgical positioning system100can include a platform assembly102and a control module110. The platform assembly102sits atop the surgical operating table and supports at least part of the pelvic region of the patient thereon. The platform assembly102can include a first mechanism104that provides lateral alignment (e.g., left-right) of the pelvic region of the patient on the surgical operating table and a second mechanism106that adjusts an elevation or height of the pelvic region of the patient with respect to the surgical operating table. For example, the elevation of the pelvic region can allow for extension of the hip of the patient, which can offer better exposure of the hip joint during replacement thereof.

In some embodiments, the platform assembly102can also include a third mechanism108that adjusts the position of an upper leg or buttock region of the patient. In other embodiments, the third mechanism108is a separate component that is coupled to part of the platform assembly102during surgery. In any embodiment, the third mechanism108can control, for example, elevation and lateral location of the proximal femur of the patient with respect to other parts of the patient (e.g., the pelvic region), which may make broaching of the femur easier.

The control module110can be operatively coupled to one or more components of the platform assembly102to provide actuation thereof. In some embodiments, the first mechanism104can be in a fixed position. Alternatively or additionally, in some embodiments, the first mechanism104can be manually actuatable from an initial stowed position to a deployed position for surgery. Alternatively or additionally, in some embodiments, the first mechanism104can be detachable from the platform assembly. In such configurations, the first mechanism104can be attached in position after a patient is disposed on the platform assembly for surgery. In some embodiments, the second mechanism106can be actuated using electrical power. For example, connection116between control module110and second mechanism106can be used to provide electrical control signals and/or electrical power to an actuator of the second mechanism106to provide the desired amount of elevation. Alternatively or additionally, in some embodiments, the second mechanism106can be actuated using hydraulic or pneumatic power. For example, connection116can be a hydraulic line that provides pressurized fluid to or withdraws fluid from the second mechanism106to provide a desired amount of elevation. In some embodiments, the third mechanism108can actuated using hydraulic or pneumatic power. For example, connection118between control module110and third mechanism108can provide pressurized air to or withdraw air from the third mechanism to provide the desired amount of elevation and/or lateralization. In some embodiments, any of the first mechanism104, second mechanism106, and third mechanism108can employ any one of manual actuation, electrical actuation, pneumatic actuation, or combinations thereof.

In some embodiments, the control module110is disposed on the floor of the operating theater, for example, underneath or otherwise nearby to the surgical operating table. In other embodiments, the control module110can be disposed on a portion of the operating table, a surgical cart proximal to the operating table, a wall of the operating theater, or any other stationary or mobile structure. In still other embodiments, the control module110can be integrated with the surgical operating table itself, for example, as part of the table base, support column, or patient supporting panels of the surgical operating table.

In some embodiments, the control module110is operatively coupled to an input unit112(e.g., via wired or wireless connection114) to receive commands for control of the components of the platform assembly102during surgery of the patient. The control module110thus translates the input commands from the input unit112into electrical signals (or movement of hydraulic fluid or air for hydraulic or pneumatic actuation) to drive operation of the components of the platform assembly102. For example, the input unit112can include one or more actuators or switches that are manually actuated by the surgeon or another operator to dictate operation of the second mechanism106and/or third mechanism108. Alternatively or additionally, the input unit112can include an electronic display or graphical user interface by which the surgeon or another operator can define desired positioning by the second mechanism106and/or third mechanism108. Alternatively or additionally, the input unit112can employ hands-free input, such as voice actuation, to dictate operation of the second mechanism106and/or third mechanism108. It is also possible for the input unit112to employ other techniques or mechanisms according to one or more contemplated embodiments.

The surgical positioning system100can thus enable multiple hip positioning options, including hip extension, elevation, and lateralization. These multiple hip positioning options allow for excellent exposure and delivery of the femur. As a result, rapid primary hip replacement procedures can be achieved. Moreover, the multiple hip positioning options offered by the surgical positioning system100can further assist with more complex hip replacement scenarios, such as obese patients, patients having significant muscle mass, and patients having an underlying deformity.

Referring now toFIGS.2-12E, an exemplary surgical positioning system200is shown. The surgical positioning system200includes a platform assembly202(also known as a pelvic elevation platform), a control unit or module204(also known as a control box), and an input unit206(e.g., left foot pedal206aand right foot pedal206b, also known as a foot pedal system). Although not shown in the figures for clarity of illustration, the control module204is operatively connected to the platform assembly202by power supply conduits (e.g., electrical, hydraulic, and/or pneumatic) and to the input unit206by respective signal lines (e.g., electrical, hydraulic, and/or pneumatic). The surgeon operating on a patient320disposed on surgical operating table210can thus interact with the input unit206to directly control positioning of the patient by the platform assembly202.

In the illustrated example ofFIG.2, the platform assembly202is disposed on surgical operating table210, in particular, a torso support panel214of the operating table210. The surgical operating table210has a head support panel212and a leg support panel216on opposite sides of the torso support panel214along a longitudinal (Y) direction. Each of the support panels212-216can be separately articulated (e.g., angled with respect to each other) and/or can be displaced along the longitudinal direction. For example, the panels212-216can be translated in a direction from the head support panel212toward the leg support panel216to allow for positioning of a detector or source (e.g., X-ray) of an imaging system to image the torso or pelvis of the patient320. The surgical operating table210can further include a base230, which may be integrated with a floor of the operating theater or movable (e.g., casters or wheels). Supporting the panels212-216on base230is a support column232, which may have an adjustable height (e.g., telescoping extending along the Z-direction) or have a static height.

Each of the support panels212,214,216of the surgical operating table210can have respective support pads220,222,224(e.g., cushions) thereon. In some embodiments, the support pads220-224are part of the surgical positioning system and are installed together with the platform assembly202. In other embodiments, the support pads220-224are part of the operating table210. The platform assembly202can be disposed between the torso support pad222and the leg support pad224along the longitudinal direction, so as to support a pelvic region of the patient320thereon. In some embodiments, a height (e.g., along the Z-direction) of the platform assembly202in the initial, non-extended position may be substantially equal to that of adjacent portions of the torso support pad222and the leg support pad224.

As shown inFIG.2, the control module204can be disposed on the floor underneath a portion of the operating table210and oriented to allow convenient routing of wiring and conduits to respective connectors of the input unit206and/or the platform assembly202. In particular, the control module204can have an input/output (I/O) connector panel234that faces toward a side of the operating table210where the input unit206is disposed and/or where connectors274,276of the platform assembly202are disposed. The I/O connector panel234can have electrical connectors238,240(FIG.3C) that are connected to the foot control pedals206a,206brespectively. The I/O connector panel234can further have a pneumatic connector236(FIG.3C) that is connected to pneumatic connector274of the platform assembly202, and another electrical connector242(FIG.3C) that is connected to electrical connector276of the platform assembly202.

As shown inFIGS.3A-3D, the control module204has a housing the encloses various components. The housing can be formed by a top cover248and a bottom support plate244. A seal256(e.g., O-ring) is provided between the perimeters of the top cover248and bottom plate244. Bottom plate244may have one or more feet258(e.g., rubberized feet) on a bottom surface, which feet rest on the floor or other surface in the operating theater. To provide pneumatic control, the control module204can include a pneumatic source250(e.g., rotary vane pump), a first valve (e.g., solenoid valve), and a second valve (e.g., pressure release or safety valve). To provide electrical power/control, the control module204can include an electrical power source255(e.g., power converter or transformer, battery, etc.). Again, electrical wiring and pneumatic lines are not shown inFIGS.3B-3Din order to more clearly illustrate the underlying components.

Referring toFIGS.4A-4D, the platform assembly202can have a bottom plate266(also known as a base plate), a top plate264, one or more elevation assemblies268, and an alignment post260(also known as a dynamic peritoneal post). Alternatively, in some embodiments, the alignment post260can be considered a separate component that is coupled to the platform assembly202. The bottom plate266is supported on the support panel of the surgical operating table and attached thereto by one or more mounting rails272. The bottom plate266can also include connections to the control module204, such as pneumatic connector274and electrical connector276. Handles296(FIG.4C) can be formed in the bottom plate266to allow hand carrying and/or positioning of the platform assembly202. Bottom plate266may have one or more feet284(e.g., rubberized feet) on a bottom surface, which feet rest on a surface of the operating table210. A cover282may be provided on otherwise exposed components of the bottom surface of the bottom plate266.

The top plate264can have support padding226over an upper surface thereof, which padding226supports the pelvic region of the patient320thereon. The top plate264and the support padding226can have a centrally-located (with respect to lateral X-direction) slot208through which alignment post260can vertically extend. The alignment post260is rotatable in the Y-Z plane from an initial stow position (seeFIGS.5A-5B), where the alignment post260is substantially horizontal and disposed between the top plate264and the bottom plate266, to a deployed position (seeFIGS.4B,8A-8C), where the alignment post260is substantially vertical and extends through the slot208.

For example, as shown inFIG.4C-4D, the alignment post260is rotatably coupled to the bottom plate266at pivot288. Support brackets286are disposed on opposite lateral sides of the post260, and pivot shaft294extends through the brackets286and the post260to hold the assembly together. Pivot heads292are also attached to the alignment post260and follow a contoured path defined by an upper surface of the brackets286, which path passively defines urging or locking positions for the alignment post260. For example, when the alignment post260is in the stowed position, pivot head292rests within recess286a, which helps maintain the post260in said position, as shown inFIG.5B. Sufficient force may be applied to the alignment post260such that pivot head292leaves recess286a, as shown inFIG.7B, after which the bracket path urges the pivot head292to recess286b. With pivot head292resting within recess286b, the alignment post260is in the fully deployed position, as shown inFIGS.8A-8C. The alignment post260may include a longitudinally extending portion290that acts to further limit the rotation by abutting a portion of the top plate264, as shown inFIG.8B.

In some embodiments, a locking plate270may be disposed over the alignment post260in the stowed position and coupling together the top plate264and bottom plate266, as shown inFIGS.5A-5B. The locking plate270may be especially useful when transporting the platform assembly, as it restricts the alignment post and the top/bottom plates from inadvertent motion. The locking plate270can be removed in order to allow for elevation of the platform assembly202and/or actuation of the alignment post260, for example, as shown inFIG.6.

The alignment post260can further include padding262to cushion contact with adjacent portions of patient320. The padding262may be symmetrical with respect to its central axis along the X-direction but asymmetrical with respect to its central axis along the Y-direction (laterally asymmetrical). Padding262can provide a rounded surface to contact a leg of the patient that is not being operated on, while the opposite surface278acts as a mounting surface for an inflatable positioning member310. In some embodiments, the padding262is removable, for example, being disposed on the alignment post260only after the post260is in its fully deployed position. For example, the padding262can have a central cavity279sized and shaped to receive a free end of the alignment post260, as shown inFIGS.10A-10B. In other embodiments, the padding262may be capable of being installed on the alignment post260when the post260is in the stowed position, or the padding262may otherwise be an integral part of the alignment post260.

As best shown inFIGS.9A-9B, the one or more elevation assemblies268are coupled to both the top plate264and bottom plate266, and can be actuated to change a vertical distance between the plates264,266(e.g., elevation of the supported portion of the patient along the Z-direction). For example, the elevation assembly268can be a scissor assembly with an upper section268a, a lower section268b, and a pair of arms300. Each section268a,268bis rigidly connected to the respective platform plate264,266. The sections268a,268balso include vertically-protruding portions298that abut each other when the elevation assembly268is in an unextended state, so as to define a minimum height of the platform assembly202. The pair of arms300are arranged in a crossing configuration and connected together at a central pivot302. First ends306of the arms300are coupled to the respective section268a,268bby fixed pivots, while opposite second ends304are capable of moving longitudinally along slots308in the sections268a,268b. An actuator, such as a linear actuator, moves the second ends304in slots308along the longitudinal axis (Y-direction), while the crossing configuration of the arms300converts the linear motion of the second ends304into vertical motion (Z-direction) between the plates264,266. For example, the elevation assemblies268may provide elevation of up to 15 cm and a lifting capacity of up to 150 kg (331 lbs.).

In some embodiments, as shown inFIGS.8A-9B, the alignment post260can maintain its height about the top plate264despite elevation of the top plate264with respect to the bottom plate266. For example, the alignment post260can include a telescoping mechanism that allows an upper end of the post260to translate vertically as the top plate264is elevated with respect to the bottom plate266. Constant positioning of the patient using the alignment post260can thus be achieved regardless of any changes in pelvic elevation.

In some embodiments, the platform assembly202can include one or more imaging alignment markers280(also known as a grid guidance template). For example, as illustrated inFIG.4E, the imaging alignment markers can have a radiopaque grid pattern. In some embodiments, the markers280may be formed as decals mounted on an upper surface of the top plate264and underneath padding226. In other embodiments, the markers280may be formed as an integral part of the top plate264or the padding226. Other locations on the platform assembly and/or configurations for markers280are also possible according to one or more contemplated embodiments. The markers280can be used to check leg length and joint offset during surgery, for example, by using X-ray imaging of the patient anatomy and underlying markers280. The use of image intensifiers in the X-ray imaging can allow for the check based on markers280to occur in substantially real-time.

The surgical positioning system200can further include a positioning member310(also known as a femoral delivery bladder), which is inflatable from a completely deflated state to a fully inflated state, as well as anywhere in between. The positioning member310can cradle a leg or buttock of the patient320thereon, with inflation of the member310causing elevation and lateralization of the femur during anterior-approach surgery. For example, the positioning member310can be a substantially L-shaped bladder, as best shown inFIGS.11A-11D. The positioning member310can have a vertically extending inner surface310athat contacts a side of the patient's leg/buttock and acts to lateralize the femur when the positioning member310is inflated. A horizontally-extending inner surface310bcontacts an underside of the patient's leg/buttock and acts to elevate the femur when the positioning member310is inflated. Opposite to surface310ais vertically-extending surface310c, which is coupled to facing surface278of the alignment post padding262. For example, the positioning member surface310cand the alignment post padding surface278can be releasably coupled together by any mechanical attachment means, such as, but not limited to, hook-and-loop fastener, permanent adhesive, reusable adhesive, latch, and/or locking clip. Alternatively or additionally, the positioning member and the alignment post can be releasably coupled together by magnetic attachment means, for example, via magnetic attraction between opposite poles of magnets in or on facing surfaces278,310cor between a magnet in or on one of the facing surfaces278,310cand a metal in or on the other of the facing surfaces278,310c. Opposite to surface310bis horizontally-extending surface310d, which rests on an upper surface of the platform padding226. In some embodiments, the surface310bmay also be coupled to the platform padding226, for example, by any mechanical or magnetic attachment means.

The positioning member310can be connected to a conduit312within the platform assembly202. The conduit312can have a female pneumatic connector314at one end that interfaces with a corresponding male pneumatic connector316of the positioning member310. The opposite end of conduit312is coupled to connector274on the bottom plate266of the platform assembly202. Thus, positioning member310can be connected to the pneumatic source of the control unit204via the platform assembly202. Alternatively, the pneumatic connection from control module204can directly connect to pneumatic connector316of the positioning member without connecting to connector274of the platform assembly202.

In some embodiments, the positioning member310may be considered a part of platform assembly202. For example, the positioning member310may be integrated with and inseparable from the alignment post260or the alignment post padding262. In another example, the positioning member310may be separable from the alignment post260and/or the alignment post padding262(e.g., via a releasable attachment mechanism), but may nevertheless be considered as part of the overall platform assembly202. In other embodiments, the positioning member310may be considered a separate part independent from the platform assembly202.

Referring toFIGS.12A-12EandFIG.19, an exemplary method600for use of surgical positioning system during surgery on a patient320will be described. The method can initiate at process block602, where the surgical operating table210is provided with the platform assembly202of surgical positioning system200. For example, an existing pelvic support pad (e.g., cushion) of the surgical operating table210between torso support pad222and leg support pad224can be removed and replaced with platform assembly202. Alternatively or additionally, the support pads220-224are part of the surgical positioning system, and process block602includes providing the support pads220-224on respective support panels212-216of the operating table as well as disposing platform assembly202between the torso support pad222and the leg support pad224.

InFIG.19, the method600can proceed to process block604, where the patient is disposed on the surgical operating table with at least a portion of the pelvis being supported on the platform assembly of the surgical positioning system. For example, as shown inFIG.12A, patient320can be disposed face-up on operating table210, with at least a portion of the pelvic region of the patient being on the support padding226of the top plate264of the platform assembly202. The groin region320amay be disposed adjacent to slot208of the platform assembly202.

InFIG.19, the method600can proceed to process block606, where the alignment post is arranged with respect to a groin of the patient. For example, as shown inFIG.12B, the alignment post260can be rotated (in the Y-Z plane) into the fully deployed position, and the padding262can be installed over the alignment post260such that the padding262abuts the groin region320a. For example, the padding262can be arranged such that the positioning member mounting surface278faces a hip320bon which surgery is to be performed as part of a hip replacement surgery.

InFIG.19, the method600can proceed to process block608, where the positioning member is installed on the platform assembly and under a leg or buttock of the patient. For example, as shown inFIG.12C, a positioning member310can be installed by temporarily raising the leg of the patient320. The positioning member310can be installed by mounting surface310cto the padding262(e.g., as shown inFIGS.11A-11B) and attaching the pneumatic connector of the platform assembly202to the positioning member310(e.g., as shown inFIGS.11C-11D). Once the positioning member310is installed, the leg or buttock of the patient is rested in the cradle formed by surfaces310a-310bof positioning member, as shown inFIG.12D. Although shown inFIGS.11A-11D and12C-12Din the fully inflated state, the positioning member will, in general, be initially installed in the fully deflated state. Inflation, whether fully or partially, may occur during particular stages of the surgical procedure, as required by the surgeon. Thus, at least initially, there may be no cradling or minimal cradling offered by the positioning member310.

InFIG.19, the method600can then proceed to process block610, where a surgeon proceeds to perform surgery on the patient, for example, a hip replacement surgery. During surgery610, the surgeon or other user may control the surgical positioning to effect desired position changes in the patient hip region. For example, surgery610can include process block612, where an elevation of the supported portion of the patient's pelvis is changed by actuating the platform assembly, and process block614, where a femur of the patient is elevated and/or lateralized by changing inflation of the positioning member. Process blocks612-614may be performed multiple times during surgery610and in any order. For example, the platform assembly202can be actuated to elevate the supported pelvis of the patient320, as shown inFIG.12E. In particular, the pelvic elevation offered by the platform assembly202can allow for extension of the hip320b, thereby providing better exposure of the joint and bones. During another stage of surgery610, with or without elevation by the platform assembly202, the positioning member310can be inflated. For example, the positioning member310can be inflated for femoral stem preparation and insertion, which inflation may elevate and lateralize the proximal femur for ease of broaching. The positioning member310can otherwise be deflated during the acetabular preparation and insertion stages.

Referring now toFIGS.13-18C, another exemplary surgical positioning system400is shown. The surgical positioning system400includes a platform assembly402(also known as a pelvic elevation platform), a control unit or module404(also known as a control box), and an input unit206(e.g., left foot pedal206aand right foot pedal206b, also known as a foot pedal system). Although not shown in the figures for clarity of illustration, the control module404is operatively connected to the platform assembly402by power supply conduits (e.g., electrical, hydraulic, and/or pneumatic) and to the input unit206by respective signal lines (e.g., electrical, hydraulic, and/or pneumatic). A surgeon operating on a patient320disposed on surgical operating table210can thus interact with the input unit206to directly control positioning of the patient by the platform assembly402.

In the illustrated example ofFIG.13, the platform assembly402is disposed on surgical operating table210, which may have a configuration similar to the surgical operating table described with respect toFIG.2above. Each of the support panels212,214,216of the surgical operating table210can have respective support pads220,222,224(e.g., cushions) thereon. In some embodiments, the support pads220-224are part of the surgical positioning system400and are installed together with the platform assembly402. In other embodiments, the support pads220-224are part of the operating table210. The platform assembly402can thus be disposed on the torso support panel214of the operating table210, between the torso support pad222and the leg support pad224along the longitudinal direction (e.g., along the Y-direction), so as to support a pelvic region of the patient320thereon. In some embodiments, a height (e.g., along the Z-direction) of the platform assembly402in the initial, non-extended position may be substantially equal to that of adjacent portions of the torso support pad222and the leg support pad224.

As shown inFIG.13, the control module404can be disposed on the floor underneath a portion of the operating table210and oriented to allow convenient routing of wiring and conduits to respective connectors of the input unit206and/or the platform assembly402. In particular, the control module404can have an input/output (I/O) connector panel434that faces toward a side of the operating table210where the input unit206is disposed and/or where connectors474,476(seeFIGS.17A-17C) of the platform assembly402are disposed. Similar to the control module204described above, the I/O connector panel434of control module404can have electrical connectors that respectively connect to foot control pedals206a,206b, a pneumatic connector that connects to pneumatic connector474of platform assembly402, and another electrical connector that connects to electrical connector476of platform assembly402. Control module404may thus have a construction and arrangement of components similar to that illustrated inFIGS.3A-3Dand described above with respect to control module204.

Referring toFIGS.14,15A-15B, and17A-17C, the platform assembly402can have a bottom plate466(also known as a base plate), a top plate464, one or more elevation assemblies, and an alignment post460(also known as a dynamic peritoneal post). Alternatively, in some embodiments, the alignment post460can be considered a separate component that is coupled to the platform assembly402. The bottom plate466is supported on the support panel of the surgical operating table and attached thereto by one or more mounting rails272. The bottom plate466can also include connections to the control module404, such as pneumatic connector474and electrical connection476. Handles can be formed in the bottom plate466, for example, as recessed portions on a bottom or side surfaces of the bottom plate466, so as to allow for hand carrying and/or positioning of the platform assembly402. Similar to bottom plate266described above, bottom plate466can have one or more feet (e.g., rubberized feet) that rest on a surface of the operating table210.

The top plate464can have support padding426(e.g., cushion) over an upper surface thereof, which padding426supports the pelvic region of the patient320thereon. In contrast to the configuration described above with respect toFIGS.2-13, the top plate464of platform assembly402includes a centrally-located (with respect to lateral X-direction) peninsular portion406that projects along the longitudinal direction (e.g., Y-direction) toward the feet of the patient320. The peninsular portion406can be arranged between legs of the patient when portions of the legs and/or buttocks of the patient are otherwise supported on padding426. The peninsular portion406can be defined by open regions408a,408bon opposite sides (with respect to lateral X-direction) of the peninsular portion406. For example, along the longitudinal direction, a length (H2) of the peninsular portion406may be about 248.5 mm compared to an overall length (H1) for the platform assembly of about 587.25 mm. For example, along the lateral direction, a length (L2) of each open region408a,408bmay be about 172.2 mm compared to an overall length (L1) of the platform assembly of about 500 mm.

An end portion of the peninsular portion406closest to the feet of the patient320may be exposed from the support padding426and can have a post bracket or mount409. An end460aof the alignment post460can be inserted into a corresponding opening409aof the post mount409for use during surgery, and the alignment post460can be removed from the post mount409when otherwise not needed (e.g., for initial positioning of the patient on the surgical operating table, for removal of the patient from the surgical operating table, and/or for transport of the surgical positioning system between operating theaters and/or different operating tables). When inserted into the post mount409, the alignment post460extends in direction away from bottom plate466and above top plate464. The alignment post460can also move with the top plate464by virtue of being inserted into post mount409, thereby maintaining a height of the alignment post460about the top plate464despite elevation of the top plate464with respect to the bottom plate466.

The alignment post460can further include padding462to cushion contact with adjacent portions of patient320. The padding462can provide a rounded surface to contact a leg of the patient that is not being operated on, while the opposite surface462a(FIG.14) acts as a mounting surface for an inflatable positioning member310. In some embodiments, the padding462is removable, for example, being disposed on the alignment post460prior to, during, or after insertion of end460ainto post mount409. For example, the padding462can have a central cavity sized and shaped to receive a free end460bof the alignment post460, as shown inFIGS.15A-15B. In other embodiments, the padding462may otherwise be an integral part of the alignment post460.

The surgical positioning system400can further include a positioning member310(also known as a femoral delivery bladder), which may have a configuration similar to the positioning member described with respect toFIGS.11A-11D. Thus, vertically-extending surface310ccan be coupled to facing surface462aof the alignment post padding462. For example, the positioning member surface310cand the alignment post padding surface462acan be releasably coupled together by any mechanical attachment means or magnetic attachment means, for example, as described above with respect toFIGS.11A-11D.

Referring toFIGS.16A-16C, the positioning member310can be connected to a conduit512within the platform assembly402. The conduit512can have a female pneumatic connector414at one end that interfaces with a corresponding male pneumatic connector316of the positioning member310. The opposite end of conduit512is coupled to connector474on the bottom plate466of the platform assembly402. Thus, positioning member310can be connected to the pneumatic source of the control unit404via the platform assembly402. Alternatively, the pneumatic connection from control module404can directly connect to pneumatic connector316of the positioning member without connecting to connector474of the platform assembly402. Prior to connection, the female pneumatic connector414can be stored in a recess in the peninsular portion406of the top plate464, as illustrated inFIGS.16A and16C. The connector414can be pulled from the recess in the peninsular portion406and coupled to corresponding connector316of the positioning member, as shown in FIG.16B. The conduit512may have sufficient slack between connector474and connector414to accommodate the movement of connector414from the peninsular portion recess to the positioning member310. Alternatively or additionally, the conduit512may have sufficient flexibility to stretch in order to accommodate the movement of connector414from the peninsular portion recess to the positioning member310.

In some embodiments, the positioning member310may be considered a part of platform assembly402. For example, the positioning member may be integrated with and inseparable from the alignment post460or the alignment post padding462. In another example, the positioning member310may be separable from the alignment post460and/or the alignment post padding462(e.g., via a releasable attachment mechanism), but may nevertheless be considered as part of the overall platform assembly402. In other embodiments, the positioning member310may be considered a separate part independent from the platform assembly402. For example, in some embodiments, positioning member310and/or alignment post padding462may be considered as a consumable or disposable component replaced for each patient or surgery, while other components of the surgical positioning system may otherwise be subject to sterilization for reuse.

As best shown inFIGS.17A-17C, the platform assembly402can include a scissor assembly468, a first telescoping hydraulic cylinder actuator502, a second telescoping hydraulic cylinder actuator504, and a drive mechanism506(e.g., electronic servo drive) that powers cylinder actuators502,504. The scissor assembly468, the cylinder actuators502,504, and/or the drive mechanism506can be considered together as a single elevation assembly or as separate elevation assemblies of the platform assembly402. The second telescoping hydraulic cylinder actuator504can be disposed along the Z-direction between the peninsular region406of the top plate464and the bottom plate466. At an end of the platform assembly402opposite the peninsular region406along the longitudinal Y-direction, the scissor assembly468can be disposed between the top plate464and the bottom plate466. The first telescoping hydraulic cylinder actuator502can be disposed along the longitudinal Y-direction between the scissor assembly468and the second telescoping hydraulic cylinder actuator504, and along the Z-direction between the top plate464and the bottom plate466. Since the first and second hydraulic cylinders502,504are disposed on a longitudinal centerline of the top plate464in a plan view of the platform assembly402, the scissor assembly468can provide some measure of rotational stability about the centerline by supporting the lateral X-direction ends of the top plate464.

The hydraulic cylinder actuators502,504can be actuated to change a vertical distance between the plates464,466(e.g., elevation of the supported portion of the patient along the Z-direction). For example, the hydraulic cylinder actuators502,504may provide elevation of up to 150 mm (e.g., 100 mm elevation shown inFIGS.17B-17C) and a lifting capacity of 150 kg (331 lbs.) or more. The first and second telescoping hydraulic cylinder actuators502,504can be coupled to together at one end via a first brace or bracket510and at intermediate portion thereof via a second brace or bracket508. The second bracket508can also support a drive mechanism506thereon. In some embodiments, the second bracket508can instead house a gear train, couplers, or other power transmission elements that allow drive mechanism506to power hydraulic cylinder actuators502,504to cause extension or retraction thereof. Electrical conduit or cable514can be connected to the drive mechanism506for providing electrical power and/or control signals thereto. For example, the cable514may extend from electrical connector476, which may in turn be coupled by another cable or electrical conduit to the appropriate electrical connector in I/O connector panel434of control unit404.

Referring toFIGS.18A-19, an exemplary method600for use of surgical positioning system during surgery on a patient320will be described. The method can initiate at process block602, where the surgical operating table210is provided with platform assembly402of surgical positioning system400. For example, an existing pelvic support pad (e.g., cushion) of the surgical operating table210between torso support pad222and leg support pad224can be removed and replaced with platform assembly402. Alternatively or additionally, the support pads220-224are part of the surgical positioning system, and process block602includes providing the support pads220-224on respective support panels212-216of the operating table as well as disposing platform assembly402between the torso support pad222and the leg support pad224.

InFIG.19, the method600can proceed to process block604, where the patient is disposed on the surgical operating table with at least a portion of the pelvis being supported on the platform assembly of the surgical positioning system. For example, as shown inFIG.18A, patient320can be disposed face-up on operating table210, with at least a portion of the pelvic region of the patient being on the support padding426of the top plate464of the platform assembly402. The groin region320amay be disposed adjacent to peninsular region406of the platform assembly402.

InFIG.19, the method600can proceed to process block606, where the alignment post is arranged with respect to a groin of the patient. For example, as shown inFIGS.15A-15B, the alignment post460can be inserted into the post mount409of the peninsular region406, and the padding462can be installed over the alignment post460such that the padding462abuts the groin region320a, as shown inFIG.18B. For example, the padding462can be arranged such that the positioning member mounting surface462afaces a hip320bon which surgery is to be performed as part of a hip replacement surgery.

InFIG.19, the method600can proceed to process block608, where the positioning member is installed on the platform assembly and under a leg or buttock of the patient. For example, a positioning member310can be installed by temporarily raising the leg of the patient320. The positioning member310can be installed by mounting surface310cto the padding462(e.g., as shown inFIGS.16A-17C) and attaching the pneumatic connector of the platform assembly402to the positioning member310(e.g., as shown inFIGS.16A-16B). Once the positioning member310is installed, the leg or buttock of the patient is rested in the cradle formed by surfaces310a-310bof positioning member, as shown inFIG.18C. Although shown inFIGS.16A-17C and18Cin the fully inflated state, the positioning member will, in general, be initially installed in the fully deflated state. Inflation, whether fully or partially, may occur during particular stages of the surgical procedure, as required by the surgeon. Thus, at least initially, there may be no cradling or minimal cradling offered by the positioning member310.

InFIG.19, the method600can then proceed to process block610, where a surgeon proceeds to perform surgery on the patient, for example, a hip replacement surgery. During surgery610, the surgeon or other user may control the surgical positioning to effect desired position changes in the patient hip region. For example, surgery610can include process block612, where an elevation of the supported portion of the patient's pelvis is changed by actuating the platform assembly, and process block614, where a femur of the patient is elevated and/or lateralized by changing inflation of the positioning member. Process blocks612-614may be performed multiple times during surgery610and in any order. For example, the platform assembly402can be actuated to elevate the supported pelvis of the patient320, as shown inFIG.17B. In particular, the pelvic elevation offered by the platform assembly402can allow for extension of the hip320b, thereby providing better exposure of the joint and bones. During another stage of surgery610, with or without elevation by the platform assembly402, the positioning member310can be inflated. For example, the positioning member310can be inflated for femoral stem preparation and insertion, which inflation may elevate and lateralize the proximal femur for ease of broaching. The positioning member310can otherwise be deflated during the acetabular preparation and insertion stages.

Although the examples described above employ specific actuation mechanisms for the elevation assemblies and the positioning members, other actuation mechanisms are also possible according to one or more contemplated embodiments. For example, in the platform assembly, the top plate can be moved with respect to the bottom plate using a screw mechanism or gear assembly paired with an appropriate electrical motor, one or more linear actuators that directly or indirectly (e.g., via a scissor mechanism or other translation mechanism) moves the top plate, one or more hydraulic actuators that directly or indirectly (e.g., via a scissor mechanism or other translation mechanism), one or more pneumatic actuators that directly or indirectly (e.g., via a scissor mechanism or other translation mechanism), or any other compact actuation assembly. For example, the positioning member can transition between deflated and inflated states using a pneumatic mechanism (e.g., pressurized air from a pump) or a hydraulic mechanism (e.g., pressurized fluid from a pump).

Although the examples described above focus on the use of the surgical positioning system for hip replacement using the direct anterior approach, embodiments of the disclosed subject matter are not limited thereto. Rather, the surgical positioning systems can be applied to other surgeries and scenarios as well. For example, the surgical positioning system can be used in trauma scenarios, where the surgeon requires access to the femoral head and/or neck to address fracture thereof. In general, the surgical positioning system can be especially useful in any surgical application where the anterior approach is used to access the femur. However, one of ordinary skill in the art will appreciate that the disclosed systems and techniques can be applied to other applications and scenarios as well.

Embodiments of the disclosed subject matter may offer one or more of the following features or advantages, among others:Modularity and portability—The various components of the surgical positioning system may be disposed in a single transport case that can be carried by a single person and transported between operating venues in a personal automobile.Cost effective—Since it is designed for use with existing surgical operating tables, the surgical positioning system can avoid the expenses associated with procuring and maintaining a specialized traction table. Moreover, since the system can be simply controlled by a single operator (e.g., the surgeon), the system can avoid the cost of extra staff necessary for operating the specialized traction table.Simpler setup and patient preparation—The surgical positioning system avoids the leg traction required in specialized traction tables. Since the parts of the patient remain substantially unrestrained, the patient can be more easily transferred, draped, and prepped in the operating room. Moreover, since the system fits mostly within the footprint of existing operating table setups, the system takes up much less room in the operating theater than a specialized traction table.Improved efficiency—Since the legs of the patient remain free, the surgeon is able to check for stability intraoperatively for both anterior and posterior at-risk positions. Moreover, the surgeon can manually palpate the feet of the patient to check for equal leg lengths, which would otherwise not be available with a specialized traction table without removing the patient therefrom. The imaging alignment marker of the system also allows the surgeon to check the reconstructive anatomy for leg length and offset in real-time during the surgery.

In some embodiments, a control module or unit can be implemented within a computing environment, such as computing environment700illustrated inFIG.20. The computing environment700is not intended to suggest any limitation as to scope of use or functionality, as the innovations may be implemented in diverse general-purpose or special-purpose computing systems. For example, the computing environment700can be any of a variety of computing devices (e.g., desktop computer, laptop computer, server computer, tablet computer, etc.).

The computing environment700includes one or more processing units710,715and memory720,725. InFIG.20, this basic configuration730is included within a dashed line. The processing units710,715execute computer-executable instructions. Each processing unit can be a general-purpose central processing unit (CPU), processor in an application-specific integrated circuit (ASIC) or any other type of processor. In a multi-processing system, multiple processing units execute computer-executable instructions to increase processing power. For example,FIG.7shows a central processing unit710as well as a graphics processing unit or co-processing unit715. The tangible memory720,725may be volatile memory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination of the two, accessible by the processing unit(s). The memory720,725stores software780implementing one or more innovations described herein, in the form of computer-executable instructions suitable for execution by the processing unit(s).

A computing system may have additional features. For example, the computing environment700includes storage740, one or more input devices750, one or more output devices760, and one or more communication connections770. An interconnection mechanism (not shown) such as a bus, controller, or network interconnects the components of the computing environment700. Typically, operating system software (not shown) provides an operating environment for other software executing in the computing environment700, and coordinates activities of the components of the computing environment700.

The tangible storage740may be removable or non-removable, and includes magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, or any other medium which can be used to store information in a non-transitory way, and which can be accessed within the computing environment700. The storage740stores instructions for the software780implementing one or more innovations described herein.

The input device(s)750may be a touch input device such as a keyboard, mouse, pen, or trackball, a voice input device, a scanning device, or another device that provides input to the computing environment700, such as foot pedals206a,206bof input unit206. The output device(s)760may be a display, printer, speaker, CD-writer, or another device that provides output from computing environment700.

The communication connection(s)770enable communication over a communication medium to another computing entity. The communication medium conveys information such as computer-executable instructions, audio or video input or output, or other data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media can use an electrical, optical, RF, or other carrier.

Some embodiments of the disclosed methods can be performed using computer-executable instructions implementing all or a portion of the disclosed technology in a computing cloud790. For example, the disclosed methods can be executed on processing units710,715located in the computing environment700and/or on servers located in the computing cloud790.

Any of the disclosed control module operations can be implemented as computer-executable instructions stored on one or more computer-readable storage media (e.g., one or more optical media discs, volatile memory components (such as DRAM or SRAM), or non-volatile memory components (such as flash memory or hard drives)) and executed on a computer (e.g., any commercially available computer, including smart phones or other mobile devices that include computing hardware). As used herein, the term computer-readable storage media does not include communication connections, such as signals, carrier waves, or other transitory signals. Any of the computer-executable instructions for implementing the disclosed techniques as well as any data created and used during implementation of the disclosed embodiments can be stored on one or more computer-readable storage media. The computer-executable instructions can be part of, for example, a dedicated software application or a software application that is accessed or downloaded via a web browser or other software application (such as a remote computing application). Such software can be executed, for example, on a single local computer (e.g., any suitable commercially available computer) or in a network environment (e.g., via the Internet, a wide-area network, a local-area network, a client-server network (such as a cloud computing network), or other such network) using one or more network computers.

For clarity, only certain selected aspects of the software-based implementations are described. Other details that are well known in the art have been omitted. For example, it should be understood that the disclosed technology is not limited to any specific computer language or program. For instance, aspects of the disclosed technology can be implemented by software written in C++, Java, Perl, any other suitable programming language. Likewise, the disclosed technology is not limited to any particular computer or type of hardware. Certain details of suitable computers and hardware are well known and need not be set forth in detail in this disclosure.

It should also be well understood that any functionality described herein can be performed, at least in part, by one or more hardware logic components, instead of software. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Program-specific Integrated Circuits (ASICs), Program-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.

Furthermore, any of the software-based embodiments (comprising, for example, computer-executable instructions for causing a computer to perform any of the disclosed methods) can be uploaded, downloaded, or remotely accessed through a suitable communication means. Such suitable communication means include, for example, the Internet, the World Wide Web, an intranet, software applications, cable (including fiber optic cable), magnetic communications, electromagnetic communications (including RF, microwave, and infrared communications), electronic communications, or other such communication means.

Additional Description of Embodiments of Interest

Clause 1. A system for positioning a patient during surgery, the system comprising:a platform assembly comprising:a first member constructed to be supported on a surgical operating table;a second member arranged over the first member and constructed to support thereon at least a first portion of a patient undergoing surgery; andan elevation assembly constructed to move the second member with respect to the first member so as to change an elevation of the first portion of the patient with respect to a second portion of the patient; andan alignment post coupled to the platform assembly.

Clause 2. The system of clause 1, wherein the alignment post is constructed to be rotated between a stowed position between the first and second members and a deployed position extending above the second member in a direction away from the first member.

Clause 3. The system of any one of clauses 1-2, wherein the alignment post is rotatably coupled to the first member.

Clause 4. The system of any one of clauses 2-3, wherein:in the stowed position, the alignment post is oriented substantially horizontally between the first and second members in a cross-sectional view, andin the deployed position, the alignment post is oriented substantially vertically with at least an end portion of the alignment post extending above the second member in the cross-sectional view.

Clause 5. The system of any one of clauses 2-4, wherein the alignment post in the deployed position is arranged such that a groin of the patient is adjacent to a longitudinal side surface of the alignment post.

Clause 6. The system of clause 1, wherein the second member has a peninsular portion arranged between legs of the patient, the peninsular portion has a post mount, and the alignment post has an end supported within the post mount.

Clause 7. The system of any one of clauses 1-6, wherein the alignment post is arranged such that a groin of the patient is adjacent to a longitudinal side surface of the alignment post.

Clause 8. The system of any one of clauses 1-7, further comprising:a positioning member coupled to the alignment post and supported on the second member, the positioning member being inflatable between a deflated state and an inflated state,wherein, in the inflated state, the positioning member displaces part of the patient thereon vertically with respect to the second member and laterally with respect to the alignment post as compared to the positioning member in the deflated state.

Clause 9. The system of clause 8, wherein the positioning member is arranged to cradle a portion of a leg of the patient proximal to a hip of the patient.

Clause 10. The system of any one of clauses 8-9, wherein the positioning member in the inflated state is constructed and positioned to simultaneously elevate and lateralize a femur of the patient.

Clause 11. The system of any one of clauses 8-10, wherein the positioning member has an L-shape in a side view, with one leg of the L-shape along and coupled at a sidewall of the alignment post, and another leg of the L-shape along and supported on an upper surface of the second member.

Clause 12. The system of any one of clauses 8-11, wherein the positioning member is coupled to the alignment post via a mechanical attachment means and/or magnetic attachment means.

Clause 13. The system of clause 12, wherein the mechanical attachment means comprises a hook-and-loop fastener, permanent adhesive, reusable adhesive, latch, locking clip, or any combination thereof.

Clause 14. The system of any one of clauses 1-13, further comprising a control module operatively coupled to the platform assembly and/or the positioning member, the control module having an input interface constructed to receive first input to control operation of the elevation assembly and to receive second input to control inflation and/or deflation of the positioning member.

Clause 15. The system of clause 14, wherein the input interface comprises one or more foot pedals that are manually actuatable by a user.

Clause 16. The system of clause any one of clauses 14-15, wherein the control module comprises:a pneumatic source constructed to supply air to or withdraw air from the positioning member;an electrical power source constructed to supply electrical power to an actuator of the elevation assembly to change the elevation of the first portion of the patient; andmechanical or electrical components that convert input signals received via the input interface into corresponding operation of the pneumatic source or the electrical power source.

Clause 17. The system of any one of clauses 1-16, wherein the actuator of the elevation assembly comprises a linear actuator or a hydraulic cylinder.

Clause 18. The system of any one of clauses 1-17, wherein the alignment post is coupled to the platform assembly such that an end portion of the alignment post is maintained at a constant height above the second member despite changes in vertical distance between the second member and the first member due to actuation of the elevation assembly.

Clause 19. The system of any one of clauses 1-18, wherein the elevation assembly comprises one or more scissor assemblies, each scissor assembly having a first arm crossing and rotatably attached to a second arm, the first arm having a first end fixed to the first plate member and a second end coupled to the second plate member, the second arm having a first end fixed to the second plate member and a second end coupled to the first plate member, each second end is movable along a longitudinal direction, and the scissor assembly is constructed such that longitudinal motion of the second ends is converted into vertical motion of the second plate member with respect to the first plate member.

Clause 20. The system of any one of clauses 1-19, wherein the second plate member has a peninsular portion arranged to between legs of the patient, the elevation assembly comprises a first hydraulic cylinder, a second hydraulic cylinder, and at least one scissor assembly, the first hydraulic cylinder is disposed between the first plate member and the peninsular portion of the second plate member along a vertical direction, the second hydraulic cylinder is disposed between the first plate member and the at least one scissor assembly along a longitudinal direction.

Clause 21. The system of any one of clauses 1-20, wherein the alignment post comprises padding covering an end portion thereof, and/or the second plate member comprises padding covering a surface facing the first portion of the patient.

Clause 22. The system of any one of clauses 1-21, wherein the second plate member comprises an imaging alignment marker.

Clause 23. The system of clause 22, wherein the imaging alignment marker has a radiopaque grid pattern.

Clause 24. The system of any one of clauses 1-23, further comprising one or more support pads constructed to be supported on the surgical operating table and to support thereon other portions of the patient besides the first portion.

Clause 25. The system of any one of clauses 1-24, wherein at least the second member comprises a top plate with padding arranged thereon to contact the first portion of the patient, and/or the first member comprises a base plate.

Clause 26. A system for positioning a patient during surgery, the system comprising first means for elevating at least a portion of a pelvis of a patient supported on a surgical operating table, and second means for elevating and lateralizing a femur of the patient.

Clause 27. The system of clause 26, further comprising third means for controlling the first means and/or the second means based on inputs from a user of the system, such as a surgeon.

Clause 28. The system of any one of clauses 26-27, wherein the first means comprises an electrical or hydraulic actuator, and/or the second means comprises an inflatable member.

Clause 29. The system of any one of clauses 1-28, wherein the system is constructed as a modular or portable system for transport between and/or use with different surgical operating tables.

Clause 30. The system of any one of clauses 1-28, wherein the system is integrated with the surgical operating table or is constructed as an integral part or component of the surgical operating table.

Clause 31. A surgical operating table comprising the system of any one of clauses 1-30.

Clause 32. A method for performing surgery employing the surgical positioning system of any one of clauses 1-30.

Clause 33. A method, comprising:providing a surgical operating table with a platform assembly of a surgical positioning system, the platform assembly comprising a first member, a second member, and an elevation assembly, the first member being supported on the surgical operating table, the second member being arranged over the first member, the elevation assembly being constructed to vertically move the second member with respect to the first member;disposing a patient on the surgical operating table with at least a portion of a pelvis of the patient being supported on the second member;arranging an alignment post of the surgical positioning with respect to a groin region of the patient;installing an inflatable positioning member on the alignment post such that at least a portion of the inflatable positioning member is between the second member and a leg or buttock of the patient; andperforming a surgery on the patient, the performing comprising:elevating the supported portion of the pelvis of the patient by actuating the elevation assembly of the platform assembly,elevating and/or lateralizing a femur of the patient by changing inflation of the inflatable positioning member, orany combination thereof.

Clause 34. The method of clause 33, wherein the arranging the alignment post comprises rotating the alignment post from an initial stowed position between the first and second members to a deployed position extending above the second member and away from the first member.

Clause 35. The method of clause 33, wherein the arranging the alignment post comprises inserting an end of the alignment post into a post mount in a peninsular portion of the second plate member, the peninsular portion being between legs of the patient, and the inserted alignment post extends above the second plate member and away from the first plate member.

Clause 36. The method of any one of clauses 33-35, wherein the positioning member is inflatable between a deflated state and an inflated state, and/or the inflatable positioning member is installed on the alignment post in the deflated state.

Clause 37. The method of any one of clauses 33-36, wherein, before or after the installing the inflatable positioning member, a pneumatic source is connected to the positioning member.

Clause 38. The method of any one of clauses 33-37, wherein the elevation assembly comprises an electrical linear actuator and/or a hydraulic actuator.

Clause 39. The method of any one of clauses 33-38, wherein the performing the surgery comprises an anterior approach to access the femur of the patient.

Clause 40. The method of any one of clauses 33-39, wherein the performing the surgery comprises replacement of a hip of the patient via a direct anterior approach.

Clause 41. The method of any one of clauses 33-40, wherein the second member comprises a top plate with padding arranged thereon to contact the first portion of the patient, and/or the first member comprises a base plate.

GENERAL CONSIDERATIONS

All features described herein are independent of one another, and, except where structurally impossible, all features described herein can be used in combination with any other feature described herein. For example, alignment marker280described with respect toFIG.4Ecan be used with platform assembly402ofFIGS.13-18. In another example, the electrical-drive elevation mechanism employed in platform assembly202ofFIGS.2-12, or components thereof, can be employed in platform assembly402ofFIGS.13-18. In still another example, the hydraulic-drive elevation mechanism employed in platform assembly402ofFIGS.13-18, or components thereof, can employed in platform assembly202ofFIGS.2-12.

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, assemblies, modules, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, assemblies, modules, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present, or problems be solved. The technologies from any example can be combined with the technologies described in any one or more of the other examples.

Although the operations of some of the disclosed embodiments are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “offer,” “provide,” or “achieve” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

As used herein, the terms “integral part,” “integrally formed,” and “unitary construction” refer to a construction that does not include any welds, fasteners, or other means for securing separately formed pieces of material to each other, or is otherwise considered to be permanently attached together.

As used herein, operations that occur “simultaneously” or “concurrently” occur generally at the same time as one another, although delays in the occurrence of operation relative to the other due to, for example, spacing between components, are expressly within the scope of the above terms, absent specific contrary language.

As used herein, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Furthermore, use of the terms “including” or “having,” as well as other forms such as “includes,” “included,” “has,” or “had,” are intended to have the same effect as “comprising” and thus should not be understood as limiting. In addition, the term “coupled” generally means physically, mechanically, chemically, magnetically, and/or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language. As used herein, “and/or” means “and” or “or,” as well as “and” and “or.”

Directions and other relative references (e.g., inner, outer, upper, lower, left, right, top, bottom, etc.) may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as “inside,” “outside,”, “top,” “bottom,” “front,” “rear,” “side,” “left,” right,” and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” part can become a “lower” part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same.

In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated examples are only preferred examples and should not be taken as limiting the scope of the disclosed technology. Rather, the scope of the invention is defined by the following claims. I therefore claim as my invention all that comes within the scope and spirit of these claims.