Patent Description:
A noteworthy trend in the medical community is the move away from performing surgery via traditional "open" techniques in favor of minimally invasive or minimal access techniques. Open surgical techniques are less desirable in that they typically require large incisions and high amounts of tissue displacement to gain access to the surgical target site, which produces concomitantly high amounts of pain, lengthened hospitalization (increasing health care costs), and high morbidity in the patient population. Less-invasive surgical techniques (including so- called "minimal access" and "minimally invasive" techniques) are gaining favor due to the fact that they involve accessing the surgical target site via incisions of substantially smaller size with greatly reduced tissue displacement requirements.

Currently available access systems require multiple inputs to actuate components in multiple directions or shifting the anchor point of the retractor from one position to another to create a customized exposure to the target surgical site. There exists a need for an access system that enables a surgeon to create a reproducible, customized exposure to the target surgical site in a faster and less complicated manner.

Examples of retraction systems for use during surgery can be found in <CIT>, <CIT> and <CIT>.

The present invention provides an assembly as set out in claim <NUM>.

In one embodiment, an assembly includes a dial and a shaft coupled to the dial. The assembly also includes a drive gear coupled to the shaft. The drive gear is configured to rotate along a first axis based on movement of the dial. The assembly also includes a first linking member located along a second axis and configured to rotate about the second axis based on contact with the drive gear as the drive gear is rotated. The second axis is perpendicular to the first axis. The assembly also includes a second linking member
located about the second axis and configured to rotate about the second axis based on rotation of the drive gear and a coupling between the first linking member and the second linking member. The assembly also includes a linking member selector configured to rotate about the first axis. The linking member selector includes a handle for rotating the linking member selector and selecting at least a position corresponding to the first linking member. The linking member also includes a cylindrical body integrally formed with the handle. The cylindrical body includes an aperture along a longitudinal axis of the cylindrical body. The cylindrical body also includes at least one protrusion configured to exert a force on the first linking member based on selection, via the handle, of the position corresponding to the first linking member. The force exerted on the first linking member causes the coupling between the first linking member and the second linking member. The aperture is configured to receive the shaft.

In another embodiment, an assembly includes a dial and a shaft coupled to the dial. The assembly also includes a drive gear coupled to the shaft. The drive gear is configured to rotate along a first axis based on movement of the dial. The assembly also includes a plurality of linking members. The plurality of linking members includes a first linking member located along a second axis and configured to rotate about the second axis based on contact with the drive gear as the drive gear is rotated. The second axis is perpendicular to the first axis. The plurality of linking members also includes a second linking member located about the second axis and configured to rotate about the second axis based on rotation of the drive gear and a coupling between the first linking member and the second linking member. The plurality of linking members also includes a third linking member located along a third axis and configured to rotate about the third axis based on contact with the drive gear as the drive gear is rotated. The third axis is perpendicular to the first axis and the second axis. The plurality of linking members also includes a fourth linking member located about the third axis and configured to rotate about the third axis based on rotation of the drive gear and a coupling between the third linking member and the fourth linking member. The assembly also includes a linking member selector configured to rotate about the first axis. The linking member selector includes a handle for rotating the linking member selector and selecting a position of a plurality of positions corresponding to the plurality of the linking members. The linking member selector also includes a cylindrical body integrally formed with the handle. The cylindrical body includes an aperture along a longitudinal axis of the cylindrical body. The cylindrical body also includes at least one protrusion configured to exert a force on at least one of the plurality of linking members based on selection, via the handle, of the position of the plurality of position corresponding to the first linking member and the third linking member. The aperture is configured to receive the shaft.

Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein:.

Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. It is furthermore to be readily understood that, although discussed below primarily within the context of spinal surgery, the surgical access system of the present invention may be employed in any number of anatomical settings to provide access to any number of different surgical target sites throughout the body. It is also expressly noted that, although shown and described herein largely within the context of lateral surgery in the lumbar spine, the access system of the present invention may be employed in any number of other spine surgery access approaches, including but not limited to posterior, postero-lateral, anterior, and antero-lateral access, and may be employed in the lumbar, thoracic and/or cervical spine, all without departing from the present invention. The surgical access system disclosed herein boasts a variety of inventive features and components that warrant patent protection, both individually and in combination.

Examples described herein include subsystems that enable a surgical retractor, including an assembly, to be used in a surgical procedure. In one example, the assembly includes a dial that is attachable and detachable to a shaft. In this example, the shaft is coupled to a drive gear. The drive gear is configured to rotate along a first axis of the assembly based on movement of the dial. In this example, the assembly also includes a first linking member that is located along a second axis of the assembly. The first linking member includes a gear and is configured to rotate about the second axis based on contact of the gear with the drive gear as the drive gear is rotated via movement of the dial. By way of example, the gear and the drive gear may be bevel gears. The assembly also includes a second linking member located along the second axis. The second linking member is configured to rotate about the second axis based on rotation of the drive gear and a coupling between the first linking member and the second linking member. In one example, the coupling between the first linking member and the second linking member is based on a mating of a first locking element of the first linking member and a second locking element of the second linking member. In one example, the assembly includes a linking member selector that is configured to rotate about the first axis of the assembly. The linking member selector includes a handle for rotating the linking member selector to a position corresponding to the first linking member. The linking member selector includes a cylindrical body that is integrally formed with the handle. The cylindrical body includes an aperture along a longitudinal axis of the cylindrical body. The cylindrical body also includes a protrusion. The protrusion is configured to exert a force on the first linking member based on selection of the position corresponding to the first linking member. The force on the first linking member causes the coupling between the first linking member and the second linking based on a linear movement of the first linking member along the second axis. The aperture is configured to receive the shaft.

Referring now to the figures, <FIG> illustrates an exploded view of an example assembly <NUM>. The assembly <NUM> comprises a body <NUM>. The body <NUM> is configured to receive a linking member selector <NUM> along a first axis <NUM>. The linking member selector <NUM> is configured to receive a shaft <NUM> that is coupled to a drive gear <NUM> via a fastener <NUM>. The shaft <NUM> is configured to receive a dial <NUM>. The body <NUM> is configured to receive a first linking member <NUM> along a second axis <NUM>. The body <NUM> includes a nut <NUM> that is configured to receive the first linking member <NUM> and a second linking member <NUM> along the second axis <NUM>. The second linking member <NUM> is configured to receive the first linking member <NUM>. The body <NUM> is configured to receive a third linking member <NUM> along a third axis <NUM>. The body <NUM> is configured to receive a center arm <NUM>. The center arm <NUM> is configured to receive the third linking member <NUM> and a fourth linking member <NUM> along the third axis <NUM>. The fourth linking member <NUM> is configured to receive the third linking member <NUM>. The body <NUM> is configured to receive a fifth linking member <NUM> along the second axis <NUM>. The body <NUM> includes a nut <NUM> that is configured to receive the fifth linking member <NUM> and a sixth linking member <NUM> along the second axis <NUM>. The sixth linking member <NUM> is configured to receive the fifth linking member <NUM>. The body <NUM> is configured to receive a seventh linking member <NUM> along the third axis <NUM>. The body <NUM> includes a nut <NUM> that is configured to receive the seventh linking member <NUM> and an eighth linking member <NUM> along the third axis <NUM>. The eighth linking member <NUM> is configured to receive the seventh linking member <NUM>. The body includes a post <NUM> along a fourth axis <NUM>. As shown in <FIG>, the first axis <NUM> is perpendicular to the second axis <NUM>, and the second axis <NUM> is perpendicular to the third axis <NUM>. Although these axes are shown to be perpendicular to one another in this example assembly <NUM>, other angles between each of the three axes are envisioned.

The linking member selector <NUM> comprises a handle <NUM> for rotating the linking member selector <NUM> about the first axis <NUM>. The linking member selector <NUM> comprises a cylindrical body <NUM> that is integrally formed with the handle <NUM>. The cylindrical body <NUM> includes an aperture <NUM> along a longitudinal axis of the cylindrical body <NUM>. The cylindrical body <NUM> comprises a plurality of protrusions <NUM>, <NUM>, <NUM>, and <NUM> as shown in <FIG>, and protrusions <NUM> and <NUM> not shown in <FIG>. The linking member selector <NUM> comprises a pointer <NUM> and a window <NUM> for aligning the linking member selector <NUM> with a position for selecting at least one linking member and for viewing a marking (not shown) on the body <NUM> that corresponds with the position. In one example, the pointer <NUM> is configured to align with a position that selects at least one linking member. In this example, one or more markings (not shown) corresponding to one or more positions for selecting at least one linking member are located along a perimeter of the body <NUM>. Continuing with this example, the one or more markings along the perimeter of the body <NUM> are visible through the window <NUM> as the linking member selector <NUM> is rotated about the first axis <NUM> to a given position associated with a given marking. In one example, the handle <NUM> is used to rotate the linking member selector <NUM> to a position that selects at least one linking member of the linking members <NUM>, <NUM>, <NUM>, and <NUM>. Based on a position selected, at least one of the protrusions of the plurality of protrusions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> will exert a force on at least one linking member of the linking members <NUM>, <NUM>, <NUM>, and <NUM>.

For example, based on a desired selection of the first linking member <NUM>, the linking member selector <NUM> is rotated about the first axis <NUM> to a given position corresponding to the first linking member <NUM>. As a result of the selection of the first linking member <NUM>, the protrusion <NUM> will exert a force on the first linking member <NUM>. The force exerted on the first linking member <NUM> causes the first linking member <NUM> to move linearly along the second axis <NUM> from a first position to a second position. In this example, the linear movement of the first linking member <NUM> from the first position to the second position will result in a coupling between the first linking member <NUM> and the second linking member <NUM>. In another example, based on rotation of the linking member selector <NUM> and a selection of the third linking member <NUM>, the protrusion <NUM> (not shown) will exert a force on the third linking member <NUM> that causes the third linking member <NUM> to move linearly along the third axis <NUM>. In this example, the linear movement of the third linking member <NUM> from a first position to a second position along the third axis <NUM> will result in a coupling between the third linking member <NUM> and the fourth linking member <NUM>. In another example, based on rotation of the linking member selector <NUM> and a selection of the fifth linking member <NUM>, one of the plurality of protrusions <NUM>, <NUM>, <NUM>, <NUM> and <NUM> (not shown) will exert a force on the fifth linking member <NUM> that causes the fifth linking member <NUM> to move linearly along the second axis <NUM>. In this example, the linear movement of the fifth linking member <NUM> from a third position to a fourth position along the second axis <NUM> will result in a coupling between the fifth linking member <NUM> and the sixth linking member <NUM>. In another example, based on rotation of the linking member selector <NUM> and a selection of the seventh linking member <NUM>, the protrusion <NUM> will exert a force on the seventh linking member <NUM> that causes the seventh linking member <NUM> to move linearly along the third axis <NUM>. In this example, the linear movement of the seventh linking member <NUM> from a third position to a fourth position along the third axis <NUM> will result in a coupling between the seventh linking member <NUM> and the eighth linking member <NUM>.

As shown in <FIG>, the aperture <NUM> of the linking member selector <NUM> is configured to receive the shaft <NUM>. In one example, the diameter of the aperture <NUM> and the diameter of the shaft <NUM> are dimensioned accordingly to allow the shaft <NUM> to rotate within the aperture <NUM> and about the first axis <NUM>. In one example, rotation of the shaft <NUM> is accomplished by movement of the dial <NUM> when the dial <NUM> is coupled to the shaft <NUM>. Rotation of the shaft <NUM> further causes rotation of the drive gear <NUM> and the linking members <NUM>, <NUM>, <NUM>, and <NUM>.

A spring <NUM> is interposed between the first linking member <NUM> and the second linking member <NUM>. A spring <NUM> is interposed between third linking member <NUM> and the fourth linking member <NUM>. A spring <NUM> is interposed between the fifth linking member <NUM> and the sixth linking member <NUM>. A spring <NUM> is interposed between the seventh linking member <NUM> and the eighth linking member <NUM>. In one example, each of the springs <NUM>, <NUM>, <NUM>, and <NUM> are configured to operate as compression springs. In this example, the springs <NUM>, <NUM>, <NUM>, and <NUM> are configured to provide a predetermined resistance between the adjacent linking members in order to maintain a distance between the two adjacent linking members that prevents them from coupling with one another. Continuing with this example, the springs <NUM>, <NUM>, <NUM>, and <NUM> are also configured to compress based on a force exerted by one of the plurality of protrusions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> on at least one of the linking members <NUM>, <NUM>, <NUM>, and <NUM>. For example, two adjacent linking members (e.g., first linking member <NUM> and second linking member <NUM>) are configured to interlock according to predetermined amount of compression on a given spring (e.g., spring <NUM>) according to a force exerted on a given linking member (e.g., linking member <NUM>) as a result of the position of the linking member selector <NUM>.

The nut <NUM> comprises an internal threaded portion that is configured to engage with a threaded portion of the second linking member <NUM>. In one example, the linking member selector <NUM> is rotated to a position that corresponds to a selection of the first linking member <NUM> and thereby causes a coupling between the first linking member <NUM> and the second linking member <NUM> as described above. In this example, the dial <NUM> is rotated in a clockwise direction about the first axis <NUM> and thereby causes a rotation in a clockwise direction of the drive gear <NUM> about the first axis <NUM> and a rotation of the first linking member <NUM> about the second axis <NUM>. Continuing with this example, as a result of the coupling between the first linking member <NUM> and the second linking member <NUM>, the second linking member <NUM> is also rotated about the second axis <NUM>. Based on contact with the internal threaded portion of the nut <NUM> and the threaded portion of the second linking member <NUM>, the rotational movement of the second linking member <NUM> is converted to a linear movement of the nut <NUM> along the second axis <NUM> and away from the body <NUM>. In this example, as the dial <NUM> is rotated in a counter-clockwise direction about the first axis <NUM>, the rotational movement of the second linking member <NUM> is converted to a linear movement of the nut <NUM> along the second axis <NUM> and towards the body <NUM>.

The center arm <NUM> comprises an internal threaded portion that is configured to engage with a threaded portion of the fourth linking member <NUM>. In one example, the linking member selector <NUM> is rotated to a position that corresponds to selection of the third linking member <NUM> and thereby causes a coupling between the third linking member <NUM> and the fourth linking member <NUM> as described above. In this example, the dial <NUM> is rotated in a clockwise direction about the first axis <NUM> and thereby causes a rotation in a clockwise direction of the drive gear <NUM><NUM> about the first axis <NUM> and a rotation of the third linking member <NUM> about the third axis <NUM>. Continuing with this example, as a result of the coupling between the third linking member <NUM> and the fourth linking member <NUM>, the fourth linking member <NUM> is also rotated about the third axis <NUM>. Based on contact with the internal threaded portion of the center arm <NUM> and the threaded portion of the fourth linking member <NUM>, the rotational movement of the fourth linking member <NUM> is converted to a linear movement of the center arm <NUM> along the third axis <NUM> and away from the body <NUM>. In this example, as the dial <NUM> is rotated in a counter-clockwise direction about the first axis <NUM>, the rotational movement of the fourth linking member <NUM> is converted to a linear movement of the center arm <NUM> along the third axis <NUM> and towards the body <NUM>.

The nut <NUM> comprises an internal threaded portion that is configured to engage with a threaded portion of the sixth linking member <NUM>. In one example, the linking member selector <NUM> is rotated to a position that corresponds to a selection of the fifth linking member <NUM> and thereby causes a coupling between the fifth linking member <NUM> and the sixth linking member <NUM> as described above. In this example, the dial <NUM> is rotated in a clockwise direction about the first axis <NUM> and thereby causes a rotation in a clockwise direction of the drive gear <NUM> about the first axis <NUM> and a rotation of the fifth linking member <NUM> about the second axis <NUM>. Continuing with this example, as a result of the coupling between the fifth linking member <NUM> and the sixth linking member <NUM>, the sixth linking member <NUM> is also rotated about the second axis <NUM>. Based on contact with the internal threaded portion of the nut <NUM> and the threaded portion of the sixth linking member <NUM>, the rotational movement of the sixth linking member <NUM> is converted to a linear movement of the nut <NUM> along the second axis <NUM> and away from the body <NUM>. In this example, as the dial <NUM> is rotated in a counter-clockwise direction about the first axis <NUM>, the rotational movement of the second linking member <NUM> is converted to a linear movement of the nut <NUM> along the second axis <NUM> and towards the body <NUM>.

The nut <NUM> comprises an internal threaded portion that is configured to engage with a threaded portion of the eighth linking member <NUM>. In one example, the linking member selector <NUM> is rotated to a position that corresponds to a selection of the seventh linking member <NUM> and thereby causes a coupling between the seventh linking member <NUM> and the eighth linking member <NUM> as described above. In this example, the dial <NUM> is rotated in a clockwise direction about the first axis <NUM> and thereby causes a rotation in a clockwise direction of the drive gear <NUM> about the first axis <NUM> and a rotation of the seventh linking member <NUM> about the third axis <NUM>. Continuing with this example, as a result of the coupling between the seventh linking member <NUM> and the eighth linking member <NUM>, the eighth linking member <NUM> is also rotated about the third axis <NUM>. Based on contact with the internal threaded portion of the nut <NUM> and the threaded portion of the eighth linking member <NUM>, the rotational movement of the eighth linking member <NUM> is converted to a linear movement of the nut <NUM> along the third axis <NUM> and towards the body <NUM>. In this example, as the dial <NUM> is rotated in a counter-clockwise direction about the first axis <NUM>, the rotational movement of the eighth linking member <NUM> is converted to a linear movement of the nut <NUM> along the third axis <NUM> and away from the body <NUM>.

In one example, the linking member selector <NUM> is rotated to a position on the body <NUM> that corresponds to a selection of the first linking member <NUM> and a selection of the fifth linking member <NUM>. In this example, a first force is exerted on the first linking member <NUM> by one of the protrusions <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> and a second force is exerted on the fifth linking member <NUM> by another one of the protrusions <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. As described above, the first force causes a coupling between first linking member <NUM> and the second linking member <NUM>. Also as described above, the second force causes a coupling between the fifth linking member <NUM> and the sixth linking member <NUM>. Continuing with this example, the dial <NUM> is rotated in a clockwise direction about the first axis <NUM> and thereby causes rotation in a clockwise direction of the drive gear <NUM> about the first axis <NUM> and a simultaneous rotation of the first linking member <NUM> and the fifth linking member <NUM> about the second axis <NUM>. In this example, as a result of the coupling between the first linking member <NUM> and the second linking member <NUM> and the coupling between the fifth linking member <NUM> and the sixth linking member <NUM>, the second linking member <NUM> and the sixth linking member <NUM> are also rotated about the second axis <NUM>. Based on contact with the internal threaded portion of the nut <NUM> and the threaded portion of the second linking member <NUM> and contact with the internal threaded portion of the nut <NUM> and the threaded portion of the sixth linking member <NUM>, the rotational movements of the second linking member <NUM> and the sixth linking member <NUM> are converted to linear movements of the nut <NUM> and the nut <NUM> along the second axis <NUM> and away from the body <NUM>. In this example, as the dial <NUM> is rotated in a counter-clockwise direction about the first axis <NUM>, the rotational movements of the second linking member <NUM> the sixth linking member <NUM> are converted to linear movements of the nut <NUM> and the nut <NUM> along the second axis <NUM> and towards the body <NUM>.

As shown in <FIG>, a post <NUM> is coupled to the body <NUM>. An anti-rotation feature <NUM> is secured to the body <NUM> at a first end of the post <NUM>. In one example, the post <NUM> is configured to attach the assembly <NUM> to an external arm (not shown) for securing the assembly <NUM> in a fixed position during a surgical procedure. In one example, the external arm is an articulating arm comprising one or more sections connected by joints that allow each section to bend or turn independently in different directions.

<FIG> illustrates an assembled view of the assembly <NUM> of <FIG>. As shown in <FIG>. the linking member selector <NUM> is in a position corresponding to the seventh linking member <NUM> (not shown). In this position, based on rotation of the dial <NUM> about the first axis <NUM>, the rotational movement of the drive gear <NUM> (not shown) about the first axis <NUM>, the rotational movement of the seventh linking member <NUM> about the third axis <NUM>, and the rotational movement of the eighth linking member <NUM> (not shown) about the third axis <NUM> will be converted to a linear movement of the nut <NUM> along the third axis <NUM> as described above.

<FIG> illustrates a view of the linking member selector <NUM> of <FIG>. As shown in <FIG>, the linking member selector <NUM> comprises a plurality of protrusions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> located along the cylindrical body <NUM>. In one example, the protrusion <NUM> is configured to extend along the entire length of the cylindrical body <NUM>. In this example, a contact position of the third linking member <NUM> along the first axis <NUM> and a contact position of the seventh linking member <NUM> along the first axis <NUM> are at a position along the first axis <NUM> that is above the contact positions corresponding to each of the protrusions <NUM>, <NUM>, and <NUM>. The difference between the contact position of the third linking member <NUM> along the first axis <NUM> and the contact positions corresponding to each of the protrusions <NUM>, <NUM>, and <NUM> along the first axis <NUM> enables only the protrusion <NUM> to exert a force on the contact position of the third linking member <NUM>. The force exerted on the third liking member <NUM> results in a coupling between the third linking member <NUM> and the fourth linking member <NUM> as described above. Similarly, the difference between the contact position of the seventh linking member <NUM> along the first axis <NUM> and the contact position corresponding to each of the protrusions <NUM>, <NUM>, and <NUM> along the first axis <NUM> enables only the protrusion <NUM> to exert a force on the contact position of the seventh linking member <NUM>. The force exerted on the seventh linking member <NUM> results in a coupling between the seventh linking member <NUM> and the eighth linking member <NUM> as described above.

In another example, a contact position of the first linking member <NUM> along the first axis <NUM> and a contact position of the fifth linking member <NUM> along the first axis <NUM> are at the same position along the first axis <NUM> as the contact positions corresponding to the protrusions <NUM>, <NUM>, and <NUM>. In this example, the corresponding positions enable only the protrusions <NUM>, <NUM>, and <NUM> to exert a force on the contact position of the first linking member <NUM>. The force exerted on the first linking member <NUM> results in a coupling between the first linking member <NUM> and the second linking member <NUM> as described above. Similarly, the same position along the first axis <NUM> of the contact position of the fifth linking member <NUM> and the contact positions corresponding to the protrusions <NUM>, <NUM>, and <NUM> enable only the protrusions <NUM>, <NUM>, and <NUM> to exert a force on the contact position of the fifth linking member <NUM>. The force exerted on the fifth linking member <NUM> results in a coupling between the fifth linking member <NUM> and the sixth linking member <NUM> as described above.

<FIG> illustrates a top view of a subset of the components of the assembly <NUM> in <FIG>. As shown in <FIG>, the linking member selector <NUM> has been rotated to a position corresponding to the first linking member <NUM> (not shown). The first linking member <NUM> comprises a first gear <NUM> located along the second axis <NUM> and configured to rotate based on contact with the drive gear <NUM> (not shown) of <FIG> as the drive gear <NUM> is rotated. The first linking member <NUM> includes locking teeth <NUM> extending from the first gear <NUM>. The second linking member <NUM> comprises locking teeth <NUM> extending from the second linking member <NUM>. The locking teeth <NUM> extending from the second linking member <NUM> are configured to interlock with the locking teeth <NUM> extending from the first gear <NUM> based on a linear movement of the first linking member <NUM> from a first position along the second axis <NUM> to a second position along the second axis <NUM>, as shown in <FIG>. In this scenario, the locking teeth <NUM> extending from the second linking member <NUM> are configured to separate from the locking teeth <NUM> extending from the first gear <NUM> based on a linear movement of the first linking member <NUM> from the second position along the second axis <NUM> to a first position along the second axis <NUM>. In one example, the second linking member <NUM> comprises a leadscrew configured to translate a rotational movement into a linear movement based on rotation of the drive gear <NUM> and the coupling between the first linking member <NUM> and the second linking member <NUM>.

<FIG> illustrates a bottom view that corresponds to the top view of <FIG>. As shown in <FIG>, the third linking member <NUM> comprises a second gear <NUM> located along the third axis <NUM> and configured to rotate based on contact with the drive gear <NUM> (not shown) of <FIG> as the drive gear <NUM> is rotated. The third linking member <NUM> includes locking teeth <NUM> extending from the second gear <NUM>. The fourth linking member <NUM> comprises locking teeth <NUM>. The locking teeth <NUM> extending from the fourth linking member <NUM> are configured to interlock with the locking teeth <NUM> extending from the second gear <NUM> based on a linear movement of the third linking member <NUM> from a first position along the third axis <NUM> to a second position along the third axis <NUM>. The locking teeth <NUM> extending from the fourth linking member <NUM> are configured to disengage from the locking teeth <NUM> extending from the second gear <NUM> based on a linear movement of the third linking member <NUM> from the second position along the third axis <NUM> to the first position along the third axis <NUM>. In one example, the fourth linking member <NUM> comprises a leadscrew configured to translate a rotational movement into a linear movement based on rotation of the drive gear <NUM> and the coupling between the third linking member <NUM> and the fourth linking member <NUM>.

As shown in <FIG>, the fifth linking member <NUM> comprises a third gear <NUM> located along the second axis <NUM> and configured to rotate based on contact with the drive gear <NUM> of <FIG> as the drive gear <NUM> is rotated. The fifth linking member <NUM> includes locking teeth <NUM> extending from the third gear <NUM>. The sixth linking member <NUM> also includes locking teeth <NUM>. The locking teeth <NUM> extending from the sixth linking member <NUM> are configured to interlock with the locking teeth <NUM> extending from the third gear based on a linear movement of the fifth linking member <NUM> from a third position along the second axis <NUM> to a fourth position, as shown in <FIG>, along the second axis <NUM>. The locking teeth <NUM>, <NUM> are configured to disengage based on a linear movement of the fifth linking member <NUM> from the fourth position along the second axis <NUM> to the third position along the second axis <NUM>.

As shown in <FIG>, the seventh linking member <NUM> comprises a fourth gear <NUM> located along the third axis <NUM> and configured to rotate based on contact with the drive gear <NUM> of <FIG> as the drive gear <NUM> is rotated. The seventh linking member <NUM> includes locking teeth <NUM> extending from the fourth gear <NUM>. The eighth linking member <NUM> also comprises locking teeth <NUM>. The locking teeth <NUM>, <NUM> are configured to interlock based on a linear movement of the seventh linking member <NUM> from a third position along the third axis <NUM> to a fourth position along the third axis <NUM>. The locking teeth <NUM>, <NUM> are configured to disengage based on a linear movement of the seventh linking member <NUM> from the fourth position along the third axis <NUM> to the third position along the third axis <NUM>.

<FIG> illustrates a bottom view of a subset of the components of the assembly <NUM> in <FIG> and <FIG>. As shown in <FIG>, the linking member selector <NUM> has been rotated to a position corresponding to the third linking member <NUM>. In this scenario, the locking teeth <NUM> extending from the fourth linking member are configured to interlock with the locking teeth <NUM> extending from the second gear <NUM> based on a linear movement of the third linking member <NUM> from a first position along the third axis <NUM> to a second position, as shown in <FIG>, along the third axis <NUM>. In this scenario, the locking teeth <NUM>, <NUM> are configured to disengage based on a linear movement of the third linking member <NUM> from the second position along the third axis <NUM> to the first position along the third axis <NUM>.

<FIG> illustrates a bottom view of a subset of the components of the assembly <NUM> in <FIG> and <FIG>. As shown in <FIG>, the linking member selector <NUM> has been rotated to a position corresponding to the fifth linking member <NUM>. In this scenario, the locking teeth <NUM>, <NUM> are configured to interlock based on a linear movement of the fifth linking member <NUM> from a third position along the second axis <NUM> to a fourth position, as shown in <FIG>, along the second axis <NUM>. In this scenario, the locking teeth <NUM>, <NUM> are configured to disengage based on a linear movement of the fifth linking member <NUM> from the fourth position along the second axis <NUM> to a third position along the second axis <NUM>.

<FIG> illustrates a bottom view of a subset of the components of the assembly <NUM> in <FIG> and <FIG>. As shown in <FIG>, the linking member selector <NUM> has been rotated to a position corresponding to the seventh linking member <NUM>. In this scenario, the locking teeth <NUM> extending from <NUM> are configured to interlock with the locking teeth <NUM> extending from the seventh linking member <NUM> based on a linear movement of the seventh linking member <NUM> from a third position along the third axis <NUM> to a fourth position, as shown in <FIG>, along the third axis <NUM>. In this scenario, the locking teeth <NUM>, <NUM> are configured to disengage based on a linear movement of the seventh linking member <NUM> from the fourth position along the third axis <NUM> to the third position along the third axis <NUM>.

<FIG> illustrates a bottom view of a subset of the components of the assembly <NUM> in <FIG> and <FIG>. As shown in <FIG>, the linking member selector <NUM> has been rotated to a position corresponding to the first linking member <NUM> and the fifth linking member <NUM>. In this scenario, the locking teeth <NUM> extending from the second linking member <NUM> are configured to interlock with or disengage from the locking teeth <NUM> extending from the first gear <NUM> as described above. Further, in this scenario, the locking teeth <NUM> extending from the sixth linking member <NUM> are configured to interlock with or disengage from with the locking teeth <NUM> extending from the third gear <NUM> as described above.

<FIG> illustrates an example pinion sub-assembly <NUM>. The pinion sub-assembly <NUM> comprises a linking member <NUM>, a spring <NUM>, a gear <NUM>, and a retaining element <NUM>. The gear <NUM> comprises locking teeth <NUM>. The linking member <NUM> is configured to receive the spring <NUM>, the gear <NUM>, and the retaining element <NUM>. The retaining element <NUM> is configured to retain the spring <NUM> and the gear <NUM> from advancing past a given position along the linking member <NUM>.

In one example, the linking members <NUM>, <NUM>, <NUM>, and <NUM>, as described above, comprise all of the components of the pinion sub-assembly <NUM>. In this example, the linking member <NUM> operates in a similar manner as described with respect to the linking members <NUM>, <NUM>, <NUM>, and <NUM>. Continuing with this example, the gear <NUM> and the locking teeth <NUM> also operate in a similar manner as described with the first gear <NUM> and the locking teeth <NUM>, the second gear <NUM> and the locking teeth <NUM>, the third gear <NUM> and the locking teeth <NUM>, and the fourth gear <NUM> and the locking teeth <NUM>, respectively. Further, in this example, the spring <NUM> is configured to compress based on a force exerted by a protrusion (e.g., one of the protrusions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of <FIG>) on the linking member <NUM> (e.g., one of the linking members <NUM>, <NUM>, <NUM>, <NUM> of <FIG>) and based on a rotational position of the locking teeth <NUM> with respect to the locking teeth of another linking member.

In one scenario, referring to <FIG>, if the tips of the locking teeth <NUM> and the tips locking teeth <NUM> are in a given rotational position along the second axis <NUM> as the first linking member <NUM> is moved linearly along the first axis <NUM> towards the second linking member <NUM>, then it is possible that the locking teeth <NUM> and <NUM> will be unable to interlock with one another as shown in <FIG>. Further, it is also possible that the linking member selector <NUM> could also become temporarily stuck in this position based on the tips of the locking teeth <NUM> and <NUM> preventing the locking teeth <NUM> and <NUM> from interlocking. In order to overcome this scenario, referring back to <FIG>, the spring <NUM> is compressed as the linking member <NUM> is moved along a linear axis towards another linking member while the tips of the locking teeth <NUM> encounter the tips of the locking teeth of another linking member at a rotational position that prevents the locking teeth <NUM> from interlocking with the locking teeth of another linking member. In this scenario, upon a rotation of the dial <NUM> and the drive gear <NUM>, the locking teeth <NUM> (e.g., the locking teeth <NUM> of <FIG>) would rotate about an axis just enough where the tips of the locking teeth <NUM> are no longer in direct contact with the tips of the locking teeth corresponding to another linking member. Continuing with this scenario, based on a rotational movement of the linking member <NUM>. the stored mechanical energy in the spring <NUM> would be released and thereby cause the linking member <NUM> (e.g., the linking member <NUM> of <FIG>) to further move along the linear axis to a given position that enables the locking teeth <NUM> (e.g., the locking teeth <NUM> of <FIG>) to interlock with the locking teeth (e.g.. the locking teeth <NUM> of <FIG>) of another linking member (e.g., the linking member <NUM> of <FIG>).

<FIG> illustrates an example surgical retractor <NUM>. The surgical retractor <NUM> comprises the assembly <NUM> of <FIG>, a right arm assembly <NUM>, and a left arm assembly <NUM>. As shown in <FIG>, the right arm assembly <NUM> comprises a channel <NUM>. The channel <NUM> is configured to receive a pin <NUM> that is coupled to the nut <NUM> of <FIG>. The right arm assembly <NUM> comprises an aperture for receiving a pin <NUM> that is coupled to the nut <NUM> of <FIG>. The left arm assembly <NUM> comprises a channel <NUM>. The channel <NUM> is configured to receive a pin <NUM> that is coupled to nut <NUM> of <FIG>. The left arm assembly <NUM> comprises an aperture for also receiving the pin <NUM> that is coupled to the nut <NUM> of <FIG>.

In one example, based on the position of linking member selector <NUM> corresponding to first linking member <NUM> (not shown) and rotation of the dial <NUM> as described above, the nut <NUM> is configured to move away from or towards the body <NUM> about the second axis <NUM>. In this example, the right arm assembly <NUM> is configured to move away from or towards the body <NUM> based on the force exerted by the pin <NUM> on the right arm assembly <NUM> in addition to the right arm assembly <NUM> being configured to pivot around the pin <NUM>.

In one example, based on the position of linking member selector <NUM> corresponding to seventh linking member <NUM> (not shown) and rotation of the dial <NUM> as described above, the nut <NUM> is configured to move away from or towards the body <NUM> about the third axis <NUM>. In this example, the right arm assembly <NUM> and left arm assembly <NUM> are configured to move away from or towards the body <NUM> based on the force exerted by the pin <NUM> on the right arm assembly <NUM> and the left arm assembly <NUM>.

In one example, based on the position of linking member selector <NUM> corresponding to fifth linking member <NUM> (not shown) and rotation of the dial <NUM> as described above, the nut <NUM> is configured to move away from or towards the body <NUM> along the second axis <NUM>. In this example, the left arm assembly <NUM> is configured to move away from or towards the body <NUM> based on the force exerted by the pin <NUM> on the left arm assembly <NUM> in addition to the left arm assembly <NUM> being configured to pivot around the pin <NUM>.

In one example, based on the position of linking member selector <NUM> corresponding to first linking member <NUM> and the fifth linking member <NUM> (not shown) and rotation of the dial <NUM> as described above, the nut <NUM> and the nut <NUM> are configured to move away from or towards the body <NUM> along the second axis <NUM>. In this example, the right arm assembly <NUM> and the left arm assembly <NUM> are configured to move away from or towards the body <NUM> based on the force exerted by the pin <NUM> on the right arm assembly <NUM>, the force exerted by the pin <NUM> on the left arm assembly <NUM>, the right arm assembly <NUM> being configured to pivot around the pin <NUM>, and the left arm assembly <NUM> being configured to pivot around the pin <NUM>.

In one example, the right arm assembly <NUM>, the left arm assembly <NUM>, and the center arm <NUM> are each configured to receive a retractor blade for use during a surgical procedure. By way of example, the retractor blades may be composed of any material suitable for introduction into the human body, including but not limited to stainless steel, aluminum, titanium, and/or clear polycarbonate, that would ensure rigidity during tissue retraction. The retractor blades may be optionally coated with a carbon fiber reinforced coating to increase strength and durability. The blades may be optionally constructed from partially or wholly radiolucent materials (e.g., aluminum, PEEK, carbon-fiber, and titanium) to improve the visibility of the surgeon during imaging (e.g.. radiographic, MRI, CT, fluoroscope, etc.). The retractor blades may also be composed of a material that would destruct when autoclaved (such as polymer containing a portion of glass particles), which may be advantageous in preventing the unauthorized re-use of the blades (which would be provided to the user in a sterile state). The retractor blades may be provided in any number of suitable lengths, depending upon the anatomical environment and surgical approach, such as (by way of example only) the range from <NUM> to <NUM>. Based on this range of sizes, the assembly <NUM> of <FIG> is extremely versatile and may be employed in any of a variety of desired surgical approaches, including but not limited to lateral, posterior, postero-lateral, anterior, and antero-lateral, by simply selecting the desired size retractor blades and attaching them to the surgical retractor <NUM>.

In one example, the retractor blades may be equipped with various additional features or components. By way of example only, one or more of the retractor blades may be equipped with a retractor extender, such as a wide retractor extender or a narrow retractor extender. The retractor extenders extend from the retractor blades to form a protective barrier to prevent the ingress or egress of instruments or biological structures (e.g., nerves, vasculature, organs, etc.. ) into or out of an operative corridor. Depending upon the anatomical setting and surgical approach, one or more of the retractor blades may be equipped with a shim element. In one example, the shim element has a distal tapered region which may be advanced into tissue (e.g. bone, soft tissue, etc.) for the purpose of anchoring the retractor blades and/or advanced into a disc space to distract the adjacent vertebral bodies (thereby restoring disc height). In similar fashion to the retractor extenders, the shim element also forms a protective barrier to prevent the ingress or egress of instruments or biological structures (e.g., nerves, vasculature, etc.) into or out of the operative corridor.

In one example, the retractor extenders and/or the shim element may be made out any material suitable for use in the human body, including but not limited to biologically compatible plastic and/or metal, preferably partially or wholly radiolucent in nature material (such as aluminum, PEEK, carbon-fibers and titanium). Construction from plastic or thin metal provides the additional benefit of allowing the shim and/or the retractor extenders to be collapsed into a compressed or low profile configuration at the skin level as the element is inserted, and then expanded once it is below skin level and within the operative corridor. In another example, the retractor extenders may have symmetric narrow configurations and/or broad configurations and/or an asymmetric configuration of narrow and broad elements. For example, any or all of the retractor extenders may be provided with a lateral section, a narrow configuration, and/or a lateral section. The retractor extenders and/or the shim element may be composed of a material that would destruct when autoclaved (such as polymer containing a portion of glass particles), which may be advantageous in preventing the unauthorized re-use of the retractor extenders and/or the shim element (which would be provided to the user in a sterile state). Slits may also be provided on the shim to improve flexibility. The retractor extenders and/or the shim element may have a parabolic concave curvature.

In one example, each of the retractor extenders and/or the shim element may be equipped with a mechanism to selectively and releasably engage with the respective retractor blades. By way of example only, this may be accomplished by configuring the retractor extenders and/or the shim element with a tab element capable of engaging with corresponding ratchet-like grooves along the inner-facing surfaces of the retractor blades. Each of the retractor extenders and/or the shim element is provided with a pair of engagement elements having, by way of example only, a generally dove-tailed cross-sectional shape. The engagement elements are dimensioned to engage with receiving portions on the respective retractor blades. In a preferred embodiment, each of the retractor extenders and/or the shim element may be provided with an elongate slot for engagement with an insertion tool. Each tab member is also equipped with an enlarged tooth element which engages within corresponding grooves provided along the inner surface of the retractor blades. On the wide retractor extenders, each includes a center portion flanked by a pair of lateral sections, which effectively increase the width of the retractor blades.

Claim 1:
An assembly (<NUM>) for actuating components of a surgical retractor comprising:
a dial (<NUM>);
a shaft (<NUM>) coupled to the dial (<NUM>);
a drive gear (<NUM>) coupled to the shaft (<NUM>), wherein the drive gear (<NUM>) is configured to rotate along a first axis (<NUM>) based on movement of the dial (<NUM>);
a first linking member (<NUM>) located along a second axis (<NUM>) and configured to rotate along the second axis (<NUM>) based on contact with the drive gear (<NUM>) as the drive gear (<NUM>) is rotated, wherein the second axis (<NUM>) is perpendicular to the first axis (<NUM>);
a second linking member (<NUM>) located along the second axis (<NUM>) and configured to rotate about the second axis (<NUM>) based on rotation of the drive gear (<NUM>) and a coupling between the first linking member (<NUM>) and the second linking member (<NUM>);
a linking member selector (<NUM>) configured to rotate about the first axis (<NUM>), the linking member selector (<NUM>) comprising:
a handle (<NUM>) for rotating the linking member selector (<NUM>) and selecting at least a position corresponding to the first linking member (<NUM>); and
a cylindrical body (<NUM>) integrally formed with the handle (<NUM>), wherein the cylindrical body (<NUM>) includes (i) an aperture (<NUM>) along a longitudinal axis of the cylindrical body (<NUM>), wherein the aperture (<NUM>) is configured to receive the shaft (<NUM>); and characterized in that the cylindrical body (<NUM>) further includes (ii) at least one protrusion configured to exert a force on the first linking member (<NUM>) based on selection, via the handle (<NUM>), of the position corresponding to the first linking member (<NUM>), wherein the force on the first linking member (<NUM>) causes the coupling between the first linking member (<NUM>) and the second linking member (<NUM>).