Expandable surgical access port

Abstract

An expandable surgical access port having an actuating arm and a membrane on the actuating arm. The arm is movable by a mechanism that operates without longitudinal movement and may have a position indicator, slots for lights and wires passing through the arm, and other features. A method for fabricating the surgical access port is also provided.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 358,651, which is incorporated herein by reference in its entirety.

Background Art

[0002] Various access ports have been proposed and used to access the delicate tissue of the brain. Accessing brain tissue, particularly internal brain tissue that is not accessible on the surface, presents various challenges. For example, it is desirable to minimize damage to the brain tissue by forming a non - invasive path for access. For this purpose, surgical access ports typically have a tapered distal end that gently spreads the tissue as the access port is moved into position at the surgical site. Once the surgical site is reached, the central portion of the access port is removed or the access port is expanded to form a path for surgical instruments.

[0003] Another problem with brain access ports is that the brain tissue can be damaged simply by contact with the walls of the access port. Intracranial pressure can compress the brain tissue in the vicinity of the access port, causing cerebral ischemia, i.e., a reduction in blood flow and oxygen, which can lead to death of the nearby brain tissue. Such damage was particularly likely to occur when a previously flat blade or spoon retractor was used to form a surgical access path. Changes to access ports having a complete circular or elliptical shape have helped to reduce the likelihood of ischemia, but this risk still remains under any circumstances where the brain tissue is compressed.

[0004] Although various brain access ports are known, there is a continuing need to improve the technology of surgical access ports.

Summary of the Invention

[0005] In one aspect, an expandable surgical access port is provided, having an actuation assembly defining an actuation assembly opening that surrounds a longitudinal axis, the actuation assembly including an actuation arm mount defining an actuation arm mount opening that surrounds at least a portion of the actuation assembly opening, the actuation arm mount having a plurality of pivot positions that surround the longitudinal axis, each pivot position defining a respective pivot axis that is perpendicular to the longitudinal axis and extends within a plane that does not intersect the longitudinal axis, an actuation arm mount, an actuation ring attached to the actuation arm mount and defining an actuation ring opening that surrounds at least a portion of the actuation assembly opening, the actuation ring being rotatable about the longitudinal axis relative to the actuation arm mount such that it rotates between a first actuation ring position and a second actuation ring position, the actuation ring remaining in a fixed position along the longitudinal axis over the entire range of movement between the first actuation ring position and the second actuation ring position, and an actuation assembly including the actuation ring. A plurality of actuation arms disposed about the longitudinal axis, each actuation arm extending distally from each proximal arm end to each distal arm end, each proximal arm end being pivotally coupled to the actuation assembly at one of the plurality of pivot positions, each actuation arm being pivotable about a respective pivot axis between a first arm position in which each distal arm end is spaced from the longitudinal axis by a respective first distance and a second arm position in which each distal arm end is spaced from the longitudinal axis by a respective second distance, the second distance being greater than the first distance, during movement of the actuating ring from the first actuation ring position to the second actuation ring position. A membrane surrounding the plurality of actuation arms and extending from a proximal membrane end adjacent to the actuation assembly to a distal membrane end, the membrane having an expandable flexible material to allow the plurality of actuation arms to move from each first position to each second position.

[0006] In some embodiments, a port housing that defines a port housing opening surrounding at least a portion of the actuator assembly opening and having a plurality of first pivot recesses, and a lock ring that defines a lock ring opening surrounding at least a portion of the actuator assembly opening and having a plurality of second pivot recesses, are provided. The lock ring is fixed to the port housing together with each of the first pivot recesses adjacent to each of the second pivot recesses, defining one of each of the pivot positions.

[0007] In some embodiments, the lock ring is fixed to the port housing by a plurality of lock tabs and corresponding lock tab receiving portions.

[0008] In some embodiments, the lock ring is attached to the port housing by a rotatable coupling.

[0009] In some embodiments, the rotatable coupling includes a plurality of sliding tabs and corresponding sliding tab receiving portions.

[0010] In some embodiments, each pivot position includes an actuator arm port that extends distally along the longitudinal axis from each pivot axis, and each actuator arm is movable within at least a portion of each actuator arm port.

[0011] In some embodiments, the actuator ring is rotatable in a first direction to actuate the actuator arms from each first arm position to each second arm position, and is rotatable in a second direction to actuate the actuator arms from each second arm position to each first arm position.

[0012] In some embodiments, the actuator ring includes a plurality of cam slots, each cam slot extending around a portion of the actuator ring opening from each first cam slot end to each second cam slot end, and each second cam slot end is closer to the longitudinal axis than each first cam slot end.

[0013] In some embodiments, each actuating arm comprises each pivot axis and each cam follower extending proximally from each pivot axis to one of each cam slots, and rotation of the actuating ring from the first actuating ring position to the second actuating ring position moves each cam follower from each first cam slot end to each second cam slot end, thereby moving each actuating arm from each first arm position to each second arm position.

[0014] In some embodiments, each pivot position comprises each cam follower port extending in the proximal direction opposite to the distal direction along the longitudinal axis from each pivot axis, and each cam follower extends through one of each cam follower ports.

[0015] In some embodiments, the actuating ring comprises a tapered inlet surface with a decreasing diameter in the distal direction.

[0016] In some embodiments, each actuating arm comprises a pivot axis located at each proximal arm end and rotatably fixing one of each plurality of pivot positions, and each linear elongated body extending from each pivot axis to each distal arm end, and each distal arm end of each actuating arm comprises an inward bend towards the longitudinal axis.

[0017] In some embodiments, at least one of the actuating arms comprises each light located at each distal arm end.

[0018] In some embodiments, at least one actuating arm comprises each slot at least partially extending from the proximal slot end to the distal slot end between each proximal arm end and each distal arm end, and each light is located at each distal slot end.

[0019] In some embodiments, at least one actuating arm comprises a light guide and one of the wires extending along the slot from the proximal slot end to the light.

[0020] In some embodiments, the proximal slot ends are at each pivot of each actuating arm.

[0021] In some embodiments, each slot is located on each outer radial surface of each actuating arm.

[0022] In some embodiments, each pivot axis is in contact with the longitudinal axis.

[0023] In some embodiments, the actuating ring is disposed proximal to the actuating arm mount.

[0024] In some embodiments, the actuating ring has an outer surface defining a gripping portion, and the gripping portion has a diameter greater than each diameter of each adjacent portion of the actuating arm mount.

[0025] In some embodiments, the actuating ring is disposed proximal to the actuating arm mount.

[0026] In some embodiments, the actuating ring includes an outer surface with knurling.

[0027] In some embodiments, the actuating ring mount further includes one or more extensions disposed proximal to or proximally from the proximal side of the actuating ring.

[0028] In some embodiments, the actuating ring mount further includes one or more extensions configured to couple to one or more of a clamp, a navigation device, and a surgical tool mount.

[0029] In some embodiments, there is further a position indicator configured to identify the position of the actuating ring relative to the actuating arm mount.

[0030] In some embodiments, the actuator arm mount includes one or more body position indicators, the actuator ring includes one or more ring position indicators, and the one or more body position indicators and the one or more ring position indicators are aligned when the actuator ring is in one or more predetermined positions relative to the actuator arm mount.

[0031] In some embodiments, the actuator ring includes an outer surface that defines a gripping portion, and the gripping portion has a diameter that is larger than the diameter of each adjacent portion of the actuator arm mount.

[0032] In some embodiments, a plurality of depth markers are spaced along the longitudinal axis and are visible on or through the membrane.

[0033] In some embodiments, an expandable surgical access port further includes a surgical tool mount configured to be fixed to the actuator arm mount, the surgical tool mount including a ring-shaped mount that defines a circular opening, and a ring-shaped connector mounted within the opening and configured to rotate about a central axis of the circular opening, the ring-shaped connector having a tool lock that is radially offset from the central axis of the circular opening.

[0034] In some embodiments, the ring connector is freely rotatable about at least a portion of the central axis of the circular opening and does not include a rotation lock.

[0035] In another exemplary aspect, an expandable surgical access port is provided, the surgical access port including an actuation assembly defining an actuation assembly opening surrounding a longitudinal axis, a plurality of actuation arms disposed about the longitudinal axis and movably attached to the actuation assembly, each actuation arm having an elongated body extending distally from the actuation assembly to each distal arm end, a flexible membrane surrounding the plurality of actuation arms and extending from a proximal membrane end adjacent the actuation assembly to a distal membrane end adjacent each distal arm end, and at least one actuation arm including each slot extending from a proximal slot end to a distal slot end between the actuation assembly and each distal arm end, and each light located at each distal slot end.

[0036] In some aspects, there is further a light connector extending along the slot from the proximal slot end to the light.

[0037] In some aspects, the light connector includes at least one of a light guide and an electric wire.

[0038] In some aspects, the proximal slot end is at each pivot joining each actuation arm to the actuation assembly.

[0039] In some aspects, the actuation assembly includes a housing internal space configured to receive a portion of the light connector, and the proximal slot end is open to the housing internal space.

[0040] In some aspects, the actuation assembly comprises: an actuation arm mount that defines an actuation arm mount opening surrounding at least a portion of the actuation assembly opening, the actuation arm mount defining respective pivot axes that are perpendicular to the longitudinal axis and extend in a plane that does not intersect the longitudinal axis; an actuation ring that is attached to the actuation arm mount and defines an actuation ring opening surrounding at least a portion of the actuation assembly opening, the actuation ring being rotatable about the longitudinal axis relative to the actuation arm mount such that it rotates between a first actuation ring position and a second actuation ring position, each of the plurality of actuation arms being pivotally coupled to the actuation assembly at one of the plurality of pivot positions, each actuation arm being pivotable about each pivot axis between a first arm position in which each distal arm end is spaced from the longitudinal axis by a respective first distance and a second arm position in which each distal arm end is spaced from the longitudinal axis by a respective second distance, each second distance being greater than each first distance, as the actuation ring moves from the first actuation ring position to the second actuation ring position.

[0041] In some aspects, the proximal slot end is at each pivot that couples each actuation arm to each pivot position.

[0042] In some aspects, the actuation ring remains at a fixed position along the longitudinal axis over the entire range of movement between the first actuation ring position and the second actuation ring position.

[0043] In some aspects, the actuation arm mount comprises: a port housing that defines a port housing opening surrounding at least a portion of the actuation assembly opening; a connector housing that defines a connector housing opening surrounding at least a portion of the actuation assembly opening, the connector housing being adjacent to the port housing and defining an internal housing space between the connector housing and the port housing; and a lock ring that defines a lock ring opening surrounding at least a portion of the actuation assembly opening.

[0044] In some embodiments, the locking ring is fixed to the connector housing with at least a portion of the port housing captured between the locking ring and the connector housing.

[0045] In some embodiments, a plurality of locking tabs extending into a portion of the port housing captured between the locking ring and the connector housing and a plurality of locking tab receivers configured to engage the plurality of locking tabs are provided.

[0046] In some embodiments, a plurality of pivot positions are defined between the locking ring and the port housing.

[0047] In some embodiments, the internal space of the actuation assembly housing extends radially from the longitudinal axis and has an opening in the proximal direction opposite the distal direction.

[0048] In some embodiments, each slot is located on an outer radial surface of each actuation arm.

[0049] In some embodiments, a flexible membrane surrounds each outer radial surface and each slot.

[0050] In some embodiments, the flexible membrane is formed in a predetermined position.

[0051] In another exemplary aspect, an expandable surgical access port is provided, including an actuation assembly defining an actuation assembly surrounding a longitudinal axis, and a plurality of actuation arms disposed around the longitudinal axis, each actuation arm extending distally from each proximal arm end to each distal arm end, each proximal arm end being movably coupled to the actuation assembly, and during operation of the actuation assembly, each distal arm end being movable between each first position spaced from the longitudinal axis by each first distance and each second position spaced from the longitudinal axis by each second distance, each second distance being greater than each first distance; a plurality of actuation arms; a membrane surrounding the plurality of actuation arms and extending distally from a proximal membrane end adjacent to the actuation assembly to a distal membrane end adjacent to each distal arm end, the membrane being overmolded on the plurality of actuation arms and having an expandable material to enable the plurality of actuation arms to move from each first position to each second position.

[0052] In some aspects, the membrane has a thermoplastic elastomer.

[0053] In some aspects, the membrane has a styrene-based olefin rubber and an elastomer based on hydrogenated isoprene, containing polypropylene as a reinforcing agent and mineral oil as a plasticizer and a processing aid.

[0054] In some aspects, the membrane has a wall thickness of 0.06096 cm to 0.2032 cm.

[0055] In some aspects, the membrane has a wall thickness of 0.0508 cm to 0.03048 cm.

[0056] In some aspects, the membrane has a wall thickness of 0.0381 cm to 0.04318 cm.

[0057] In some aspects, the membrane is expandable up to at least 250% at the distal membrane end.

[0058] In some embodiments, the membrane is expandable up to at least 300% at the distal membrane end.

[0059] In some embodiments, the membrane is expandable up to at least 350% at the distal membrane end.

[0060] In some embodiments, the membrane is expandable from a diameter of 1.016 cm or less to a diameter of 2.032 cm or more at the distal membrane end.

[0061] In some embodiments, the membrane is expandable from a diameter of 0.762 cm or less to a diameter of 2.286 cm or more at the distal membrane end.

[0062] In some embodiments, the membrane is expandable from a diameter of 0.635 cm or less to a diameter of 2.54 cm or more at the distal membrane end.

[0063] In some embodiments, the membrane comprises each rib located on the outer radial surface of each actuating arm and each wall extending between each adjacent pair of the plurality of ribs.

[0064] In some embodiments, the membrane comprises a lip that wraps around each distal arm end.

[0065] In some embodiments, each actuating arm comprises each outer radial surface, each outer radial surface comprises each slot that at least partially extends between each proximal arm end and each distal arm end, and each portion of the overmolded flexible membrane material extends into each slot.

[0066] In some embodiments, at least one of each slot contains a light received between each slot and each portion of the overmolded flexible membrane.

[0067] In another exemplary aspect, a method for manufacturing an expandable surgical access port is provided, the method comprising providing an actuating assembly defining an actuating assembly opening surrounding a longitudinal axis; providing a plurality of actuating arms disposed about the longitudinal axis, each actuating arm extending distally from each proximal arm end to each distal arm end, each proximal arm end being movably coupled to the actuating assembly, each distal arm end being movable during operation of the actuating assembly between each first position spaced from the longitudinal axis by each first distance and each second position spaced from the longitudinal axis by each second distance, each second distance being greater than each first distance; overmolding a membrane onto the plurality of actuating arms, the membrane extending distally from a proximal membrane end adjacent the actuating assembly to a distal membrane end adjacent each distal arm end, the membrane comprising a flexible material that is expandable to allow the plurality of actuating arms to move from each first position to each second position.

[0068] In some aspects, the membrane includes a thermoplastic elastomer.

[0069] In some aspects, the membrane includes styrene-based olefin rubber and an elastomer based on hydrogenated isoprene containing polypropylene as a reinforcing agent and mineral oil as a plasticizer and processing aid.

[0070] In some aspects, the membrane has a wall thickness of 0.06096 cm to 0.2032 cm.

[0071] In some aspects, the membrane has a wall thickness of 0.0508 cm to 0.03048 cm.

[0072] In some aspects, the membrane has a wall thickness of 0.0381 cm to 0.04318 cm.

[0073] In some embodiments, the membrane is expandable to at least 250% at the distal membrane end.

[0074] In some embodiments, the membrane is expandable to at least 300% at the distal membrane end.

[0075] In some embodiments, the membrane is expandable to at least 350% at the distal membrane end.

[0076] In some embodiments, the membrane is expandable from a diameter of 1.016 cm or less to a diameter of 2.032 cm or more at the distal membrane end.

[0077] In some embodiments, the membrane is expandable from a diameter of 0.762 cm or less to a diameter of 2.286 cm or more at the distal membrane end.

[0078] In some embodiments, the membrane is expandable from a diameter of 0.635 cm or less to a diameter of 2.54 cm or more at the distal membrane end.

[0079] In some embodiments, each actuating arm has each outer radial surface, and the step of overmolding a membrane on the plurality of actuating arms includes overmolding the membrane on each outer radial surface of each actuating arm.

[0080] In some embodiments, each actuating arm has each slot extending at least partially along each outer radial surface, and the step of overmolding the membrane includes overmolding each portion of the membrane material into each slot.

[0081] In some embodiments, at least one of each slot contains a light, and the step of overmolding the membrane includes accommodating the light between each slot and the membrane.

[0082] In some embodiments, the step of overmolding the membrane includes forming each rib located on the outer radial surface of each actuating arm and each wall extending between each adjacent pair of the plurality of ribs.

[0083] In some embodiments, the step of overmolding the membrane includes overmolding a lip that wraps around each distal arm end.

[0084] In another exemplary embodiment, an expandable surgical access port assembly is provided. An actuation assembly defining an actuation assembly opening surrounding a longitudinal axis, and a plurality of actuation arms disposed about the longitudinal axis, each actuation arm extending distally from each proximal arm end to each distal arm end in the actuation assembly, each proximal arm end being movable during operation of the actuation assembly between each first position where each distal arm end is spaced from the longitudinal axis by each minimum distance and each second position where each distal arm end is spaced from the longitudinal axis by each maximum distance, each maximum distance being greater than each minimum distance; a plurality of actuation arms; a membrane surrounding the plurality of actuation arms and extending distally from a proximal membrane end adjacent to the actuation assembly to a distal membrane end, the membrane being expandable to allow the plurality of actuation arms to move from the longitudinal axis; and an introducer extending from a proximal introducer end to a distal introducer end, the introducer having a tubular wall defining a cannula extending into the introducer from the proximal introducer end to a point adjacent to the distal introducer end, an introducer tip located at the distal introducer end and being tapered such that it increases in size proximally to a first introducer diameter, and an outer annular recess located proximally to the introducer tip and including a region having a second introducer diameter, the second introducer diameter being less than the first introducer diameter. The introducer is selectively insertable through the actuation assembly opening and is coupled to the actuation assembly in an operative position, the cannula is positioned along the longitudinal axis, the introducer tip extends distally beyond each distal arm end, and at least a portion of each distal arm end is disposed within the outer annular recess with the introducer in the operative position and the plurality of actuation arms in each first position.

[0085] In some embodiments, each actuation arm includes a respective pivot disposed at each proximal arm end and rotatably fixed to an actuation ring assembly at each pivot location.

[0086] In some embodiments, each actuation arm is configured to pivot about a respective pivot axis, and each pivot axis is in contact with the longitudinal axis.

[0087] In some embodiments, each actuating arm comprises a respective elongate body that is linear and extends from a respective pivot to a respective distal arm end.

[0088] In some embodiments, the distal arm end of each actuating arm comprises an inward bend that faces the longitudinal axis, and each inward bend is positioned within an annular recess when the plurality of actuating arms or each is in a respective first position.

[0089] In some embodiments, with the introducer in the operative position and the plurality of actuating arms in their respective first positions, the introducer tip and the plurality of actuating arms or membranes form a continuous tapered outer wall.

[0090] In some embodiments, the introducer cannula terminates at a distal introducer end in a probe tip receiving portion configured to hold one or more different navigation probe tips.

[0091] In some embodiments, the actuation assembly comprises an inner surface that surrounds an actuation assembly opening, the introducer comprises an outer surface, and with the introducer in the operative position, the outer surface contacts the inner surface to prevent movement of the outer surface in a direction perpendicular to the longitudinal axis.

[0092] In some embodiments, at least one of the inner surface and the outer surface is tapered such that the diameter decreases distally.

[0093] In some embodiments, the inner surface and the outer surface are tapered such that the diameter decreases distally.

[0094] In some embodiments, the inner surface and the outer surface each comprise a respective conical surface.

[0095] In some embodiments, the respective conical surfaces of the inner surface and the outer surface have respective taper angles that match.

[0096] In some embodiments, the actuation assembly includes a plurality of position indicators configured to indicate when a plurality of actuation arms are in at least one of respective first positions and respective second positions.

[0097] In some embodiments, the actuation assembly includes a plurality of position indicators configured to indicate when a plurality of actuation arms are in respective intermediate positions between respective first positions and respective second positions.

[0098] In some embodiments, each intermediate position includes a position at which distal arm ends are spaced apart by a first introducer diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Embodiments will now be disclosed, by way of example and not limitation, with reference to the accompanying drawings.

Figure 1

Figures 2A - 2B

Figures 3A - 3B

Figures 4A - 4B

Figures 5A - 5D

Figures 6A - 6D

Figures 7A - 7D

Figures 8A - 8B

Figures 9A - 9D

Figures 10A - 10D

Figures 11A - 11C

Figure 12

Figures 13 - 14

Figures 15A - 15C

Figures 16A - 16C

Figures 17A - 17B

Figures 18A - 18B

Figures 19A - 19C

Figures 20A - 20B

Figures 21A - 21B

Figures 22A - 22B

Figure 22C

Figures 23A - 23B

Figures 24A - 24B

Figure 25

Figure 26

[0100] The present disclosure provides non-limiting examples of embodiments of an expandable brain access port. Specific details of these embodiments are provided to aid understanding, but such details are not intended to limit the technical scope of any of the appended claims, except where specifically recited in the claims. Also, it will be understood that particular details not currently recited in the claims, or currently not recited in the claims, may, in particular, through consideration of the prior art and other factors, be added to the claims in the future should it become apparent that such details provide an advantage over the known art.

[0101] A first example of the expandable access port 100 is shown in FIG. 1. The expandable access port 100 generally includes an actuation assembly 102, an expandable port 104, and an introducer 106. Details of these features are described below. The expandable access port 100 is configured to hold or provide access for one or more surgical instruments such as an endoscope, a cutting tool, a suction hose, a light, and a navigation device. For this purpose, the actuation assembly 102 defines an actuation assembly opening 102a that surrounds the longitudinal axis 100a of the expandable access port 100.

[0102] In the case of FIG. 1, the expandable access port 100 is configured to hold a navigation probe 126 disposed inside the expandable access port 100. The navigation probe 126 is coupled to a tracking system that monitors the position of the navigation probe 126. A typical navigation probe 126 and tracking system are registered to track the position of the tip 126b of the probe and the actuation of the probe shaft 126a. When integrated into the expandable access port 100, if the probe tip 126b is incorporated into the distal expandable access port 100 of the introducer 106, the probe tip 126b is located at the distal tip of the introducer 106, and the preset registration of the navigation probe 126 can be simply used to track the introducer tip, and as a result, the position of the remaining portion of the expandable access port 100 can be assumed or estimated. Regardless of the actual positions of the probe tip 126b and the probe shaft 126a, it is also possible to align the navigation probe 126 to track the complete shape and position of the expandable access port 100. For example, if the probe tip 126b is seated at a certain distance from the distal end of the introducer 106, the offset can be programmed into the tracking system to account for this known offset. It is also possible to align the exact shape of the expandable access port 100 and / or the expandable port 104 to track the overall shape of the device. Such navigation probes 126 and their tracking systems, including methods for setting offsets and determining the shape of the device, are known in the art and need not be described in detail herein.

[0103] The probe block 130 is provided to selectively hold the navigation probe 126 in a fixed position relative to the expandable access port 100. Non-limiting examples of suitable probe blocks 130 can be found in U.S. Patent Application No. 17 / 473,282 (Publication No. 2021 / 0401457), which is incorporated herein by reference. Other examples and details of the probe block 130 are provided below.

[0104] In use, the actuating assembly 102 and the expandable port 104 may be provided as an assembled structure that is not generally intended to disassemble (e.g., without reversible fasteners such as screws), although this is not strictly required. The introducer 106 can be secured to the actuating assembly 102 and the expandable port 104 to facilitate non-invasive insertion of the expandable access port 100 into the surgical site of the brain. The navigation probe 126 can be used to assist in accurately orienting the expandable access port 100 to the surgical site. Once inserted into the desired position, the introducer 106 is removed and the actuating assembly 102 is operated to expand the expandable port 104. At the end of the surgery, the expandable access port 100 is withdrawn from the brain. The expandable port 104 may or may not be retracted prior to withdrawing the expandable access port 100.

[0105] Figures 2A - 3B are similar to the embodiment of FIG. 1 but show another embodiment of the expandable access port 100 with certain alternative structures as described below. Figures 2A and 2B show the expandable access port 100 with the expandable port 104 in the contracted position, and Figures 3A and 3B show the expandable port 104 in the expanded position. In both cases, the introducer 106 is assembled to the remainder of the expandable access port 100. As shown in FIG. 2A, the expandable port 104 extends along the longitudinal axis 100a in the distal direction D from the actuating assembly 102. To aid in explaining the features of this specification, FIG. 2A also shows the proximal direction P, which is opposite to the distal direction D.

[0106] FIG. 3B also shows the navigation probe 126 at a predetermined position inside the introducer 106 and the guide arm 128 attached to the actuating assembly 102. The guide arm 128 also functions as a tracking device for directly monitoring the position of the expandable access port 100 after the navigation probe 126 is removed or when the device is used without the navigation probe 126. Details of the guide arm 128 are provided below.

[0107] Exemplary embodiments of the actuation assembly 102 are shown in FIGS. 4A-8B. The actuation assembly 102 generally includes a port housing 108 and a lock ring 110 that are assembled together to form an actuation arm mount, and an actuation ring 112 that is movably attached to the actuation arm mount. The port housing 108 defines a port housing opening 108a, the lock ring 110 defines a lock ring opening 100a, and the actuation ring 112 defines an actuation ring opening 112a. The port housing opening 108a, the lock ring opening 100a, and the actuation ring opening 112a are aligned and each surrounds or defines at least a portion of the actuation assembly opening 102a.

[0108] In this example, the actuation ring 112 is rotatably attached to the actuation arm mount as described below, whereby the actuation ring 112 rotates relative to the actuation arm mount about the longitudinal axis 100a between a first actuation ring position and a second actuation ring position. The first actuation ring position is shown in FIGS. 2A and 2B, in which the expandable port 104 is in the retracted position. The second actuation ring position is shown in FIGS. 3A and 3B, in which the expandable port 104 is in the extended position.

[0109] As best shown in FIGS. 4A-5D, the port housing 108 comprises a generally ring-shaped structure defining a port housing opening 108a. The port housing 108 includes a plurality of first pivot recesses 108b that surround the longitudinal axis 100a. Similarly, the lock ring 110 is a generally ring-shaped structure defining a lock ring opening 100a and includes a plurality of second pivot recesses 110b that surround the longitudinal axis 100a. The port housing 108 and the lock ring 110 are secured together such that the first pivot recesses 108b and the second pivot recesses 110b collectively form a cavity that defines respective pivot positions 102b (see FIGS. 13 and 14). The pivot positions 102b can have a cylindrical shape (as shown), a spherical shape, or any other shape suitable for holding a corresponding pivot to rotate about a fixed axis. The pivot positions 102b are distributed around the longitudinal axis 100a and each define a respective pivot axis 108g (see FIGS. 5B and 6A). The pivot axes 108g are in a common plane perpendicular to the longitudinal axis 100a. The pivot axes 108g are oriented so as not to intersect the longitudinal axis 100a. Each pivot axis 108g also preferably extends tangentially to the longitudinal axis 100a (i.e., tangentially to a virtual circle centered on the longitudinal axis 100a), and each pivot axis 108g is equidistant at the position closest to the longitudinal axis 100a. As shown in FIGS. 5B and 6A, which show six pivot axes 108g spaced at an angle of 60° around the longitudinal axis 100a, the pivot axes 108g can be circumferentially equidistantly arranged.

[0110] The locking ring 110 is fixed to the port housing 108 by any suitable means. For example, each locking ring 110 is fixed to the port housing 108 by locking tabs 110d that are snap-fitted into respective locking tab receiving portions 108d, preferably in a manner that does not facilitate easy detachment. In the illustrated example, the locking tabs 110d are provided on the locking ring 110 and the locking tab receiving portions 108d are provided on the port housing 108, but this configuration can be reversed, in whole or in part (i.e., one or more of the locking tab receiving portions 108d may be on the locking ring 110 and one or more of the locking tabs 110d may be on the port housing 108). In other cases, the locking ring 110 and the port housing 108 may be joined by an adhesive, ultrasonic welding, rivets, reversible mechanical fasteners (e.g., screws), etc.

[0111] The port housing 108 and / or the locking ring 110 may include auxiliary structures to enhance their usefulness. For example, the port housing 108 can include one or more extensions 108f to which the introducer 106 and accessories (such as surgical tools, navigation devices, etc.) can be attached. The extensions 108f can also be configured to be clamped to hold the expandable access port 100 in a fixed position relative to the patient, operating table, or surgical frame. Each extension 108f may include a locking mechanism 108j or may be shaped to couple to locking portions provided at different locations. Details of such locking portions are not the subject of the present disclosure and are well known in the art and need not be described herein.

[0112] The actuating arm mounting body (coupling port housing 108 and lock ring 110) may include a plurality of extension portions 108f (for example, two to four extension portions 108f). Further, the extension portions 108f may be arranged on one side of the actuating arm mounting body (that is, within a 180° region around the longitudinal axis 100a, or more preferably within a 90° region). Thereby, the surgeon can have greater access without occluding the opposite side of the actuating arm mounting body.

[0113] As described above, the actuating ring 112 is fixed to the actuating arm mounting body so as to rotate about the longitudinal axis 100a with respect to the actuating arm mounting body. In this example, the port housing 108 includes a plurality of sliding tabs 108e that snap fit into corresponding sliding tab receiving portions 112c within the actuating ring 112. Each sliding tab receiving portion 112c includes a circumferential slot having a relatively narrow width in the radial direction and an end portion having a slightly wider width in the radial direction. Each sliding tab 108e terminates with a hook that can be inserted into the wider end portion of each sliding tab receiving portion 112c and then slides along the narrower portion of the sliding tab receiving portion 112c to rotate the actuating ring 112 relative to the port housing 108. A hook or protrusion (not shown) can be provided between the wider and narrower portions of each sliding tab receiving portion 112c to prevent each sliding tab 108e from returning to the wider portion of the sliding tab receiving portion 112c. Thus, the components cannot accidentally disassemble during use and, more preferably, cannot be disassembled under any normal circumstances (for example, without damaging the components).

[0114] In the illustrated example, the sliding tabs 108e are provided on the port housing 108 and the sliding tab receiving portions 112c are provided on the actuating ring 112, but this configuration can be reversed in whole or in part (that is, one or more of the sliding tabs 108e may be on the actuating ring 112 and one or more of the sliding tab receiving portions 112c may be on the port housing 108). Also, the sliding tabs 108e and / or the sliding tab receiving portions 112c may be provided on the lock ring 110 instead of the port housing 108.

[0115] In other embodiments, the actuating ring 112 may be rotatably fixed to the actuating arm mount using other couplings. For example, the actuating ring 112 may be captured in place relative to the actuating arm mount by a central locking ring that is threaded into the actuating arm mount. As another example, pins or screws may be inserted through the sliding tab receptacle 112c and fixed to the actuating arm mount to capture the actuating ring 112 in place. Other alternative forms and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0116] In yet other embodiments, the actuating ring 112 may be attached to an actuating arm mount that moves in a direction other than the rotation described above. For example, the actuating ring 112 may be mounted on a rail so as to slide laterally relative to the actuating arm mount.

[0117] Referring to FIG. 2A (as an example), the actuating ring 112 is preferably disposed proximal to the port housing 108. This prevents access to the actuating ring 112 when the actuating arm mount is fixed in place at the surgical site. Further, the configuration of the sliding tab 108e and the sliding tab receptacle 112c allows the actuating ring 112 to rotate relative to the actuating arm mount over its entire range of motion while remaining in a fixed position along the longitudinal axis 100a. This configuration minimizes the overall length of the expandable access port 100 and prevents the generation of unnecessary axial forces along the longitudinal axis 100a when the actuating ring 112 is rotated relative to the actuating arm mount. Although preferred, this configuration is not required in all embodiments.

[0118] As also shown in FIGS. 1, 17A, and 17B, the actuating ring 112 may have an outer surface that defines a gripping portion 112b, which optionally may have a diameter larger than an adjacent portion of the actuating arm mount. This also provides a tactile distinction between the actuating ring 112 and the actuating arm mount, helping to ensure that a rotational force is not accidentally applied to the actuating arm mount during operation, and facilitating ease of use by enhancing the surgeon's ability to firmly hold the actuating ring 112.

[0119] As shown in FIG. 2A, one or more of the plurality of extensions 108f may extend to be located proximal 112f of the actuating ring 112 or spaced in the proximal direction. For example, one or more of the plurality of extensions 108f may be secured to the ring-shaped portion of the port housing 108 via an extension base 108h that extends in the proximal direction P. This configuration makes the extensions 108f more accessible for attachment and positional locking to an accessory and allows the expandable port 104 to be positioned deeper within the brain.

[0120] Referring to FIGS. 8A-8B, the actuation assembly 102 can include an actuation ring cover 114 that covers the proximal side 112f of the actuation ring 112. The actuation ring cover 114 surrounds the proximal side of the sliding tab receiving portion 112c to prevent the entry of liquid or other substances that may interfere with the operation of the actuation ring 112. The actuation ring cover 114 has an actuation ring cover opening 114a that is concentric with the actuation ring opening 112a. As best shown in FIGS. 13 and 14, the actuation ring 112 can define a first tapered inlet surface 112e, and the actuation ring cover 114 can define a second tapered inlet surface 114b that aligns to form a continuous tapered inlet to the actuation assembly opening 102a that decreases in diameter in the distal direction D. The actuation ring cover 114 can be fixed to the actuation ring 112 by any means such as an adhesive, snap fit, ultrasonic welding, etc. In this example, the actuation ring cover 114 has pins 114c that are fixed to the holes 112i (see the figure of the adjacent surface of the actuation ring 112). One or all of the actuation ring cover 114, the first tapered inlet surface 112e, and the actuation ring cover opening 114a may be omitted.

[0121] Details of the expandable port 104 are described in connection with FIGS. 9A-10D. The expandable port 104 generally includes a plurality of actuation arms 116 and a membrane 118.

[0122] Each actuating arm 116 includes an elongated body 116a that extends in the distal direction D from each proximal arm end 116g to each distal arm end 116d. The proximal arm end 116g of each actuating arm 116 is pivotably attached to the actuating arm mounting body by each pivot 116c. In this example, each pivot 116c is captured in place at each pivot position 102b and includes a cylindrical body that extends along each pivot axis 108g when the actuating arm 116 is assembled to the actuating arm mounting body (i.e., when the pivot 116c is captured between each first pivot recess 108b and each second pivot recess 110b). This allows the actuating arm 116 to pivot about each pivot axis 108g. In other cases, the pivot 116c may include a sphere, a separately provided pin inserted through a hole in the actuating arm 116, and the like.

[0123] Each actuating arm 116 is pivotable between a first arm position (see FIG. 2A) where the distal arm end 116d is a first distance D1 from the longitudinal axis 100a and a second arm position (see FIG. 3A) where the distal arm end 116d is a second distance D2 from the longitudinal axis 100a. The second distance D2 is greater than the first distance D1. The actuating ring 112 is operable to move the actuating arms 116 between their respective first and second arm positions. More specifically, the actuating ring 112 is rotatable between a first actuating ring position where the actuating arm 116 is in the first arm position and a second actuating ring position where the actuating arm 116 is in the second arm position.

[0124] The actuating arm 116 cannot be moved closer than a first distance D1, preferably to prevent the actuating arm 116 from pinching brain tissue when the actuating arm 116 is retracted in the absence of the introducer 106. This can be achieved, for example, by configuring the actuating ring 112 such that the actuating arm 116 cannot move inward beyond a first position, by providing a stop that contacts the actuating arm 116, or by fabricating the actuating arms such that they converge to contact each other along their circumferential sides at the first position. Other alternative forms and embodiments will be apparent to those skilled in the art upon consideration of the present disclosure.

[0125] In this example, the actuating ring 112 moves the actuating arm 116 by engagement between each cam slot 112d within the actuating ring 112 and each cam follower 116b at the proximal arm end 116g of each slot 116e. As shown in FIG. 7A, the cam slot 112d is formed as a recess on the underside of the actuating ring 112. As the name indicates, each cam slot 112d is formed as an eccentric ramp centered about the longitudinal axis 100a. Specifically, each cam slot 112d extends around a portion of the actuating ring opening 112a from each first cam slot end 112d' to each second cam slot end 112d", and each second cam slot end 112d" is closer to the longitudinal axis 100a than each first cam slot end 112d'. The portion of the cam slot 112d between the first cam slot end 112d' and the second cam slot end 112d" may be linear, arcuate (shown), or may have any other smooth continuous shape that performs the functions described herein.

[0126] Each cam follower 116b extends into one of each of the cam slots 112d, and when the actuating ring 112 is rotated relative to the actuating arm mounting body, the cam slots 112d actuate each cam follower 116b toward or away from the longitudinal axis 100a depending on the direction of rotation. In this case, each actuating arm 116 acts as a class 1 lever together with a pivot 116c disposed between the cam follower 116b and the distal arm end 116d. Thus, when the cam follower 116b is located at the first cam slot end 112d', the distal arm end 116d is located at each first arm position to contract the expandable port 104, and when the cam follower 116b is located at the second cam slot end 112d', the distal arm end 116d is located at each second arm position to expand the expandable port 104. The cam slots 112d can include inwardly extending protrusions (not shown) to provide one or more positions where movement of each cam follower 116b is blocked without applying a significant torque to the actuating ring 112. Such protrusions can be positioned to establish a predetermined position where the actuating arm 116 is held in one or more positions. For example, protrusions may be provided to hold the actuating arm 116 in each first position or second position, or any position therebetween. Such protrusions can assist the surgeon in feeling where the set position is. To perform the same function, other shapes such as bends in the cam slots 112d can be provided.

[0127] The cam slots 112d can be shaped such that the cam follower 116b cannot backdrive the actuating ring 112. Specifically, the contact angle between the cam follower 116b and the cam slots 112d can be selected such that the force applied to rotate the actuating arm 116 generates a frictional load that prevents relative movement between the components. This angle can be determined using conventional engineering principles (e.g., the coefficient of static friction of an object on an inclined plane) and need not be described in further detail herein.

[0128] The cam slot 112d may also be shaped to capture both sides of the cam follower 116b so that the actuating arm 116 cannot move freely in either direction. This prevents the actuating arm 116 from moving beyond the position indicated by one side of the cam slot surface and provides accurate control of the position of the arm when rotating the actuating ring 112 in alternating directions. This is beneficial as it enables the surgeon to apply an actuating force without relying on an elastic force (e.g., pressure from brain tissue) to tilt the actuating arm 116 when it is desired to accurately open and close the actuating arm 116, preferably to any desired position, or to retract the arm. The cam slot 112d is also preferably configured to prevent the actuating ring 112 from moving to actuate the actuating arm 116 beyond their respective first positions, such as by terminating each cam slot 112d at a closed end that stops on the cam follower 116b.

[0129] In other embodiments, the actuating ring 112 can be configured to act as a second class lever on the actuating arm 116. For example, the cam slot 112d and the cam follower 116b may be disposed between the pivot 116c and the distal arm end 116d of each actuating arm 116. Other alternative forms and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0130] The actuation arm attachment body is configured to enable engagement between the cam slot 112d and the cam follower 116b, such as by including each cam follower port 110c that passes through the lock ring 110 to the proximal side 110e of the lock ring 110 for accommodating each cam follower 116b. Similarly, the actuation arm attachment body is configured to enable the actuation arm 116 to rotate distally from each pivot position 102b, such as by providing each actuation arm port 108c distally of each pivot position 102b. The cam follower port 110c and / or the actuation arm port 108c may be dimensioned to prevent excessive movement of the actuation arm 116 when the actuation ring 112 is removed from the actuation arm attachment body.

[0131] In the illustrated example, the mechanism is configured such that all of the actuation arms 116 always move together, thus ensuring that the device maintains a generally uniform circular shape during opening and closing. However, other embodiments may have features for regulating or disabling the movement of one or more of the actuation arms 116.

[0132] The membrane 118 surrounds the actuation arm 116 and extends from a proximal membrane end 118a adjacent to the actuation assembly 102 to a distal membrane end 118b adjacent to the distal arm end 116d. The membrane 118 includes a flexible material that is expandable to enable the distal arm end 116d to move from each first position to each second position. The membrane 118 may be fixed to the actuation arm 116, but is preferably overmolded onto the actuation arm 116. The overmolding can be accomplished by placing the assembled actuation assembly 102 and actuation arm 116 within a mold that receives the actuation arm 116 and injecting a membrane material into the mold to surround each actuation arm.

[0133] The membrane 118 can include any suitable material that provides a desired degree of elongation. For example, the membrane 118 can include styrene-based olefin rubber and an elastomer based on hydrogenated isoprene that contain a thermoplastic elastomer and / or contain polypropylene as a reinforcing agent and contain mineral oil as a plasticizer and processing aid.

[0134] As shown in FIG. 10D, the membrane 118 may be shaped to have a generally circular cross-sectional profile as viewed along the longitudinal axis 100a. The membrane 118 may also be shaped to have each separate rib 118d located on each respective actuating arm 116 and each wall 118e located between each adjacent pair of the actuating arms 116. As shown in FIG. 10D, each rib 118d may have a diameter slightly larger than the adjacent wall 118e, but this is not essential. The ribs 118d may be shaped to completely surround each actuating arm 116, or they may surround only the respective outer radial surface 116h (i.e., the side facing away from the longitudinal axis 100a) of each actuating arm 116. The membrane 118 can extend completely from the actuating assembly 102 to the distal arm end 116d and can include a lip 118c that wraps around the distal arm end 116d.

[0135] The membrane 118 can also include depth markers 118f (see FIG. 10B) that can be printed on the membrane 118 or formed as ridges or protrusions. The depth markers 118f can include numbers (e.g., numbers indicating dimensions or relative positions) or other shapes (e.g., letters) to identify the location of each respective depth marker 118f. The depth markers can also include printed images or ridges / protrusions defined on the actuating arms 116 that can be seen through the membrane 108. Other alternative forms and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0136] The membrane 118 can have any suitable dimensions. For example, the membrane 118 can have a wall thickness of from 0.06096 cm to 0.02032 cm, more preferably from 0.0508 cm to 0.03048 cm, and even more preferably from 0.00381 cm to 0.04318 cm. In one embodiment, the membrane 118 can have a nominal wall thickness of 0.04064 cm. It will be understood that these and other dimensions herein are subject to manufacturing tolerances, and the recited numbers are intended to include typical variations resulting from manufacturing tolerances.

[0137] The membrane 118 may also be selected to provide a desired degree of expansion to allow the actuating arm 116 to open to a desired second arm position. For example, the membrane 118 can be selected to expand by at least 250% of its original circumference at the maximum extension point (typically the distal membrane end 118b). More preferably, the membrane 118 can be selected to expand to at least 300%, and even more preferably 350% at the maximum extension point. This expansion is shown in FIGS. 13 and 14 as the change between the membrane diameter MD1 at the distal membrane end 118b in FIG. 13 and the membrane diameter MD2 at the distal membrane end 118b in FIG. 14.

[0138] The membrane 118 may also have a size suitable for use as a brain retractor. For example, the membrane 118 may have a contracted diameter MD1 of 1.016 cm and an expanded diameter of 2.032 cm or more. In other cases, the membrane 118 can have a contracted diameter MD1 of 0.762 cm and an expanded diameter of 2.286 cm or more. In still other cases, the membrane 118 may have a contracted diameter MD1 of 0.635 cm and an expanded diameter of 2.54 cm or more.

[0139] Referring again to FIGS. 9A - 9D and also to FIG. 12, one or more of the actuating arms 116 can include a light 120. The light 120 can include a light - emitting diode (LED), the end portion of a light guide (e.g., an optical fiber cable), and the like. The actuating arm 116 may also be formed as a light guide optically coupled to a remote light source. In the illustrated example, one or more actuating arms 116 are formed from a transparent material (e.g., polycarbonate plastic) and have an LED light 120 disposed adjacent to the distal arm end 116d. Light from the light 120 can pass through the distal arm end 116d and reach the surgical site. The distal arm end 116d may also be formed in a shape or have a surface treatment that helps to direct and distribute light at the surgical site. Such shapes (e.g., Fresnel - type lenses or pyramid - shaped bumps) and surface treatments for directing and distributing light are known in the art.

[0140] The light 120 may be attached to the inner surface of the actuating arm 116 or elsewhere. Preferably, the light 120 is attached within a receiving portion 116f recessed within the actuating arm 116. The actuating arm 116 has a slot 116e that communicates with the receiving portion 116f. The slot 116e is dimensioned to receive an optical connector 122, such as a light guide or an electrical wire, to supply power to the light 120. In the illustrated example, the slot 116e extends along the actuating arm 116 from a proximal slot end 116e' to a distal slot end 116e" adjacent to the light receiving portion 116f. The proximal slot end 116e' can be located at or near the pivot 116c or any other location where access for the optical connector 122 to enter the slot 116e can be provided.

[0141] Slot 116e can be disposed at any portion of the actuating arm 116, but preferably extends along the outer radial surface 116h. In this case, the membrane 118 can be overmolded onto the outer radial surface 116h such that a portion of the rib 118d is overmolded into the slot 116e. In this case, the engagement between the membrane 118 and the outer radial surface 116h serves to hold the rib 118d in place when the actuating arm 116 moves to its second (extended) position. When fully constructed, the membrane 118 also encapsulates the light 120 and the optical connector 122 between the outer radial surface 116h and the membrane 118, and thus holds the light 120 in place during use and keeps the light 120 from contacting the brain tissue.

[0142] Also, it will be understood that one or more actuating arms 116 may include a slot 116e or other shape for the purpose of receiving the overmolded portion of the membrane 118 (i.e., without the light 120) to strengthen the bond between the actuating arm 116 and the membrane 118.

[0143] Referring now to FIGS. 11A - 14, its interaction with the exemplary introducer 106 and the remaining portion of the expandable access port 100 is described in detail. The introducer 106 extends from a proximal introducer end 106a to a distal introducer end 106b and has a tubular wall 106c that defines a cannula 106d. The cannula 106d extends along the longitudinal axis 100a from the proximal introducer end 106a to a point adjacent the distal introducer end 106b. The cannula 106d terminates at a probe tip receiving portion 106g configured to receive one or more different navigation probes 126. When fully inserted, the probe shaft 126a extends along the cannula 106d and the probe tip portion 126b seats within the probe tip receiving portion 106g to hold the probe tip portion 126b in place.

[0144] At the distal introducer end 106b, the introducer 106 has a tapered introducer tip 106e that tapers in the proximal direction P to a diameter ID1. The introducer tip 106e may optionally have an opening that leads to a probe tip receiving portion 106g that can help relieve the pressure in the brain when the expandable access port 100 is inserted. Proximal to the introducer tip 106e, the introducer 106 has an outer annular recess 106f. The annular recess 106f is a region of the tubular wall 106c having a diameter ID2 that is reduced compared to the maximum diameter ID1 of the introducer tip 106e.

[0145] The introducer 106 is coupled to the remaining portion of the expandable access port 100 by inserting it through the actuator assembly opening 102a and securing the proximal introducer end 106a to the actuator arm mount. In this case, the introducer 106 has a mounting tab 106j that extends radially from the tubular wall 106c and overlaps and couples to one of the extensions 108f, thus holding the introducer 106 in an operating position where the expandable access port 100 can be inserted into the brain to the surgical site. In the operating position, the cannula 106d extends along the longitudinal axis 100a and the introducer tip 106e extends distally in the distal direction D beyond the distal arm end 116d. This configuration is best shown in FIGS. 12 and 13.

[0146] With the introducer 106 in the operative position and the actuating arms 116 in their respective first (contracted) positions, at least a portion of each distal arm end 116d is received within the annular recess 106f. This helps prevent the distal arm ends 116d from pulling on the brain tissue when the expandable access port 100 is inserted and prevents the brain tissue from pulling the actuating arms 116 away from the introducer 106. Further, each actuating arm 116 also preferably includes an inward bend 116i at its distal arm end 116d to help form a continuous tapered outer wall 106i that extends from the distal introducer end 106b to a point along or behind the annular recess 106f. Each inward bend 116i comprises a portion of each actuating arm 116 that bends towards the longitudinal axis 100a to form a tapered portion of the outer radial surface 116h. In the illustrated example, the inward bend 116i is located at the end of the straight portion of the elongated body 116a. At least a portion of each inward bend 116i extends into the annular recess 106f, and the outer surface of the inward bend 116i (or a portion of the membrane 118 surrounding the inward bend 116i) preferably forms a curved taper that gradually transitions between the taper angle of the introducer tip 106e and the taper angle of the straight portion of the outer radial surface 116h. However, it is also contemplated that the inward bend 116i may contact the slot 116e or the straight portion of the elongated body 116a at an acute angle.

[0147] The foregoing configuration provides several advantages. First, the portion of the continuous tapered outer wall 106i formed by the introducer tip 106e and the inward bend 116i presents a non-invasive shape for inserting the expandable access port 100 into the brain. At the same time, the inward bend 116i can be relatively widened compared to an arm that extends straight to the introducer tip 106e, which helps increase the rigidity of the actuating arms 116 at their distal arm ends 116d. Further, the inward bend 116i also presents a curved surface to the brain tissue when the expandable port 104 is expanded, as shown in FIG. 14, which is expected to reduce the likelihood and / or severity of ischemia along the distal arm ends 116d and the distal membrane ends 118b.

[0148] The introducer 106 may also include other features to enhance its usefulness. For example, the proximal introducer end 106a may be formed with a tapered inlet 106h to assist in guiding the navigation probe 126 within the cannula 106d. The introducer 106 may also be configured to closely fit with the actuation assembly 102 to hold the introducer 106 against movement perpendicular to the longitudinal axis 100a (i.e., lateral movement). For example, the introducer 106 may have an introducer outer surface 106l that contacts a corresponding lock ring inner surface 110f of the actuation ring inner surface 112h, preventing lateral movement of the proximal introducer end 106a relative to the actuation assembly 102. One or more of the introducer outer surface 106l, the lock ring inner surface 110f, and the actuation ring inner surface 112h may also be tapered such that their size decreases in the distal direction D. For example, the introducer outer surface 106l and the lock ring inner surface 110f may have a matching taper angle TA, or all three of the introducer outer surface 106l, the lock ring inner surface 110f, and the actuation ring inner surface 112h may potentially have a matching taper angle. In this case, when the introducer 106 is assembled to the remainder of the expandable access port 100, the matching taper angle prevents the introducer 106 from moving laterally relative to the remainder of the expandable access port 100 and holds the introducer 106 in a fixed position along the longitudinal axis 100a, preventing insertion beyond the desired position. The matching taper angle may also suppress or prevent relative rotation of the introducer 106, the lock ring 110, and the actuation ring 112, thereby preventing accidental rotation of the actuation ring 112 when the expandable access port 100 is inserted in place.

[0149] It will be appreciated that a structure comparable to the lock ring inner surface 110f may alternatively be provided on any other part of the actuation assembly 102, such as by being formed as the inner wall of the port housing 108 and / or the actuation ring cover 114. Other alternative forms and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0150] Other embodiments of the specific features are shown in FIGS. 15A - 18B. These embodiments can be used together or in combination with other embodiments described herein.

[0151] FIGS. 15A - 16C show an embodiment of the port housing 108. This embodiment is similar to the embodiment of FIGS. 5A - 5D but includes a connector housing 108m and other features to facilitate the coupling of the light source or light 120 to the light guide. In this case, the port housing 108 includes one or more slots 108k that preferably extend substantially radially from one of the first pivot recesses 108b. When the port housing 108 is assembled with the lock ring 110, the slots 108k each provide access to each light 120, such as an electrical wire or an optical fiber cable.

[0152] The connector housing 108m is fixed to the remainder of the actuating arm mounting body so as to form an internal housing space 108p (see FIG. 18A) for receiving the optical connector 122. More specifically, the connector housing 108m has an outer connector housing body 108n that includes the portion of the port housing 108 where the slots 108k extend. The outer connector housing body 108n also has a connector housing opening 108q through which the optical connector 122 is coupled to the power supply voltage or the light source. The connector housing opening 108q can be disposed at any suitable position. In this case, the connector housing opening 108q is provided on a connector housing extension 108o that extends radially from the remainder of the port housing 108. The connector housing extension 108o is optionally disposed under the extension 108f to relatively reduce the obstruction to the operating room.

[0153] In this embodiment, the lock tab receiving portion 108d is provided in the connector housing 108m such that the lock tab 110d of the lock ring 110 is coupled to the connector housing 108m, using the main body of the port housing 108 captured at an appropriate position between the lock ring 110 and the connector housing 108m. The lock tab receiving portion 108d may be recessed toward the lock ring 110 and may be configured to fit into the alignment tab receiving recess 108l formed at the bottom of the main body of the port housing 108, whereby the overall height of the assembled port housing 108 is reduced.

[0154] The actuating arm mounting body also includes one or more body position indicators 108i. The body position indicators 108i are visual and optionally tactile indicators for indicating the rotational position of the actuating ring 112 relative to the port housing 108. As shown in FIGS. 17A - 17B, the actuating ring 112 similarly has one or more ring position indicators 112g that align with the body position indicators 108i in different ways depending on the rotational position of the actuating ring 112 relative to the port housing 108. In this case, the actuating ring 112 has a single ring position indicator 112g and the port housing 108 has three body position indicators 108i arranged at different circumferential positions. The body position indicators 108i are provided on the connector housing 108m in this case, but alternatively may be provided on the main body of the port housing 108 or at other locations on the actuating arm mounting body.

[0155] When the actuation assembly 102 is assembled, the ring position indicator 112g is positioned adjacent to the first body position indicator 108i' when the actuation ring 112 is in the first position (i.e., when the expandable port 104 is contracted), and the second body position indicator 108i' is positioned when the actuation ring 112 is in the second position (i.e., when the expandable port 104 is expanded). When the actuation ring 112 is in an intermediate position, the ring position indicator 112g is aligned with a third body position indicator 108i" that is positioned between the other two body position indicators 108i', 108i". This third body position indicator 108i" can be useful when the surgeon does not desire to fully expand the expandable port 104. In other embodiments, more or fewer body position indicators 108i can be used.

[0156] The intermediate position can advantageously be a position where the distal arm end 116d and the membrane lip 118c (if present) are immediately radially outside the annular recess 106f of the introducer 106. Stated another way, the intermediate position is a position where the distal arm end 116d and the membrane lip 118c (if present) are radially spaced by the maximum diameter ID1 of the introducer tip 106e, thereby allowing the introducer 106 to be freely removed proximally without interfering with the actuation arm 116 and other parts of the expandable structure. This allows the surgeon to open the actuation arm 116 by the minimum amount necessary to remove the introducer 106, which can be useful in some situations.

[0157] Figures 17A-17B also show an actuation ring 112 having serrations in the gripping portion 112b to improve the feel and usability of the actuation ring 112. Knurling can be replaced with other structures, such as rubber or other high-friction rings, to improve the gripping portion. The actuation ring 112 can also (or alternatively) include one or more handles or levers (not shown) for operating the actuation ring 112. The actuation ring 112 also includes the ring position indicator 112g.

[0158] Figures 18A - 18B are cross - sectional views showing the assembly of various components in detail. Here, it can be seen that the lock ring 110 is coupled to the lock tab receiving portion 108d via the lock tab 110d, fixing the connector housing 108m to the remaining portion of the port housing 108 and capturing the body of the port housing 108 in a predetermined position. Also, Figure 18A shows the internal housing space 108p formed between the connector housing 108m and the remaining portion of the port housing 108, and shows how the slot 108k aligns with the proximal slot end 116e' of the associated actuating arm 116 to provide a passage for the optical connector 122. The coupling of the port housing 108 to the actuating ring 112 via the sliding tab 108e is also shown. These figures also show how the cam follower 116b extends through the cam follower port 110c to engage the cam slot 112d, the interaction between the tapered actuating ring inner surface 112h, the introducer outer surface 106l, and the lock ring inner surface 110f, and other features.

[0159] Figures 19A - 19C show an example of a surgical tool mount 124 that can be used with an embodiment of the expandable access port 100. The surgical tool mount 124 includes a tab 124a configured to be fixed to the extension 108f and a connector 124b configured to fix or guide surgical instruments such as an endoscope, a suction hose, a light, etc. In this case, the connector 124b comprises a cylindrical clip having an open side, allowing the clip to flex and generate a restoring force to hold the instrument in a predetermined position. Other embodiments may have different structures as will be apparent to those skilled in the art in view of the present disclosure.

[0160] Figures 20A - 20B show an example of a guiding arm 128 that can be used with an embodiment of the expandable access port 100. As is known in the art, the guiding arm 128 includes a tab 128a configured to be attached to the expandable access port 100, such as by fixing to the extension portion 108f, and an array of indicators 128b, such as reflective spheres or disks, used to visually track the position of the guiding arm 128 via a positioning navigation system. The indicators 128b are preferably attached so as to extend at an angle away from the longitudinal axis 100a from the tab 128a, helping to clear the area above the expandable access port 100 for surgery. Similar indicators 128b can also be used with the navigation probe 126, as is known in the art. Additionally, the indicators 128b may be directly integrated into the body of the expandable access port 100, such as by attaching to the extension portion 108f or a plurality of extension portions 108f. Other alternative forms and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0161] Figures 21A - 21B show another embodiment of the guiding arm 128. In this case, the guiding arm 128 also includes a tab 128a for coupling to the expandable access port 100 (such as by fixing to the extension portion 108f) and an array of indicators 128b. Here, the guiding arm 128 is provided as a two - part assembly having a base 128c to which a plurality of indicators 128b are attached. In this example, the indicators 128b are attached to a frame 128d that fits into corresponding openings 128e in the base 128c. A magnet or other fastener may be used to selectively couple the frame 128d to the base 128c. This configuration allows for the use of different arrays of indicators 128b. For example, different frames 128d can be provided with indicators 128b at different positions corresponding to the spatial requirements or specific requirements of different tracking systems.

[0162] FIG. 21B also shows how the guiding arm 128 can be attached to the rest of the expandable access port 100. In this case, the guiding arm tab 128a is fixed to the introducer attachment tab 106j by a lock 128a'. The introducer attachment tab 106j is fixed to the extension 108f of the port housing by its own lock 106j'. Thus, the guiding arm 128 can be removed separately or in combination with the introducer 106.

[0163] Figures 22A - 22C illustrate an example of a probe block 130 that can be used to align and hold a navigation probe 126 with an expandable access port 100. The probe block 130 includes a lock body 130a that extends within an introducer 106, and a tab 130b that can be coupled to an extension 108f of the port housing. The tab 130b includes or is configured to secure any suitable lock 130b'. The lock body 130a includes a central passage 130c having a threaded hole 130d at its proximal end, and one or more flexible arms 130e at its distal end. The threaded hole 130d receives a male thread 130h' or a lock nut 130h. The lock nut 130h has a central hole for receiving a probe shaft and has tapered fingers 130h". The tapered fingers 130h" are radially inwardly compressed by the inner wall of the central passage 130c when the lock nut 130h is threaded into the threaded hole 130d, thereby clamping the navigation probe 126 in a predetermined position. The flexible arms 130e serve to enable navigation probes having different diameters to be used in the probe block 130 by bending to conform to the diameter of a particular probe. When the components are assembled, the central passage 130c may be collinear with the longitudinal axis 100a, although this is not strictly required. The lock body 130a may be coupled to the tab 130b by a ring body 130f having an opening 130g through which a surgeon can view the introducer. Examples of various suitable probe features are provided in U.S. Patent Application No. 17 / 473,282 (published as U.S. Patent Application Publication No. 2021 / 0401457), which is incorporated herein by reference.

[0164] Figures 23A and 23B show the probe block 130 of FIGS. 22A-22C with an expandable access port attached. In this case, the arm 116 and the membrane 118 are removed to view the shape of this alternative introducer 106, which is conical. The conical introducer 106 is sized to fit closely within the space formed by the arm 116 when the arm 116 is in the folded position, thereby supporting the arm 116 and helping to prevent unwanted flexion as the access port moves to the surgical site. As shown in the figure, the tab 130b can be attached to the rest of the assembly by coupling its lock 130b' to the tab 106j of the introducer 106. The introducer tab 106j is then attached by a lock 106j' to one of the extensions 108f of the port housing. Other embodiments may couple the components in other ways.

[0165] Figures 24A and 24B show another example of the surgical tool mount 124. In this case, the surgical tool mount 124 includes a tab 124a configured to be fixed to the extension 108f of the port housing via a lock 124a', and a ring-shaped attachment body 124c. The ring-shaped attachment body 124c has a circular central opening 124d surrounding the actuation assembly opening 102a, and a connector 124b that fits within the central opening 124d. The connector 124b is preferably configured to rotate within the central opening 124d. For example, the connector 124b may have an outer rim 124e that fits over the upper portion of an inner rim 124f formed in the central opening 124d, and a tab 124g that surrounds the bottom of the inner rim 124f. The outer rim 124e and the tab 124g capture the inner rim 124f, preventing the connector 124b from separating from the ring-shaped attachment body 124c while still forming an annular space that allows the connector 124b to rotate within the ring-shaped attachment body 124c. The ring-shaped connector 124b as shown is expected to provide smooth rotation by the mating circular surfaces, allowing the surgeon to position the endoscope 132 or other device in the most convenient position. In addition, the connector 124b can be made without any kind of locking device, and as a result, it can always be freely movable as needed during the surgery. However, a movement stop may be provided to limit the rotation to a specific range. The friction between the connector 124b and the ring-shaped attachment body 124c can hold the connector 124b in a fixed position until the surgeon applies a force to rotate the connector 124b. Although free mobility is desired in some embodiments, in other cases, a lock such as a thumb screw can be provided to hold the connector 124b in a fixed position.

[0166] Connector 124b can include any suitable mechanism for holding any one or more types of surgical instruments. For example, connector 124b can have a tool connector in the form of an inner ring 124h sized to hold endoscope 132. In this case, inner ring 124h is located radially outside of connector 124b, such that when the instrument is installed, it is offset from longitudinal axis 100a. For example, in the illustrated embodiment, inner ring 124h is radially offset from the central axis of opening 124i. The remaining portion of connector 124b is located within central opening 124d of ring-shaped attachment body 124c and preferably has an opening 124i that surrounds longitudinal axis 100a. In this way, the instrument can be positioned at any desired angular position around longitudinal axis 100a and still allow access to other instruments used within expandable access port 100.

[0167] Inner ring 124h (or other type of tool connector) can use any suitable locking or retention mechanism to hold the instrument. For example, inner ring 124h can have a circular opening sized to snugly fit the outer surface of endoscope 132 such that endoscope 132 can be manually moved distally and proximally by the surgeon while inner ring 124h holds the endoscope in any position when the surgeon releases it. Inner ring 124h can also have a radial slot such that inner ring 124h is defined by two arms, where the arms can be flexible to provide an elastic force for gripping a surgical instrument disposed between the arms. A separate locking device such as a locking screw can also be used. Materials such as overmolded high friction elastomers can be used to modify the operation of inner ring 124h. Other embodiments can use a clamp compression nut arrangement (such as threaded hole 130d and nut 130h, for example). Other alternatives and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0168] FIG. 26 shows a cross-section of an exemplary introducer 106 of FIGS. 23A and 23B to show any additional details. The introducer 106 is similar to the introducer of FIGS. 11A-11C, but has an integral lock 106j’, a continuous conical taper wall 106c forming a cannula 106d, and a separately formed tip unit 106m. The tip unit 106m includes an introducer tip portion 106e and optionally an annular recess 106f. The tip unit 106m is configured to be permanently or removably attached to the remainder of the introducer 106. In the illustrated example, the tip unit 106m has a female thread 106n that engages a male thread 106o on the taper wall 106c. In other cases, a snap attachment (e.g., a non-reversible snap connector) may be used, or the tip unit 106m may be fixed by an adhesive, welding, etc.

[0169] The tip unit 106m is provided to enable the use of different navigation devices having different probe shaft lengths. For example, in the illustrated embodiment, the cannula 106d of the introducer terminates to form a probe tip receiving portion 106g’ at the end of the conical taper wall 106c. In use, the probe shaft tip portion seats within the probe tip receiving portion 106g’ and is offset from the distal introducer end 106b by a fixed known distance. This distance can be used to offset the calibration of the navigation system. Thus, if the probe shaft is not long enough to extend to the distal introducer end 106b, the two-part introducer shown in FIG. 26 can be used to account for the shorter length.

[0170] The introducer 106 of FIG. 26 can also be modified in various ways. For example, the cannula 106d of the introducer may terminate in a simple opening that allows the navigation probe shaft to seat within the probe tip receiving portion 106g” within the tip unit 106m. It is also envisioned that introducers 106 having various structures may be provided as kits for use in different configurations required by particular situations. For example, the introducer tip unit 106m can comprise one or more introducer bodies (i.e., having a probe tip receiving portion 106g’) as shown, along with one or more introducer bodies having an opening that allows the probe shaft to pass therethrough within the tip unit 106m. This can be useful, for example, to allow a surgeon to select between different introducer lengths and configurations for a particular case and then attach the tip to the desired introducer body for use in the surgery. Other alternatives and embodiments will be apparent to those skilled in the art in view of the present disclosure.

[0171] Although the embodiments of the expandable access port 100 have been described in detail, the operation will be understood. For example, the expandable access port 100 couples the introducer 106 to the actuation assembly 102 such that the introducer tip 106e is positioned distally beyond the distal arm end 116d, rotates the actuation ring 112 to move the actuation arm 116 to a first (contracted) position, then inserts the assembled expandable access port 100 into the surgical site, operates the actuation ring 112 to move the actuation arm 116 to a second (expanded) position, removes the introducer 106, and is operated by performing a surgical procedure through the expansion 104. Additional optional steps are not limited, but as known in the art, installing a navigation probe 126 within the introducer 106, or attaching a guiding arm 128 to the actuation assembly 102, and using the navigation probe 126 or the guiding arm 128 to guide the expandable access port 100 to a predetermined position using stereotactic navigation. Also, the navigation probe 126 can be attached to the introducer 106 to guide the expandable access port 100 during initial insertion, and the guiding arm 128 can be used to continue positioning while the expandable access port 100 is being used for surgery or to reposition the expandable access port 100 during surgery. Other optional steps include operating a light 120 to illuminate the surgical site and attaching a surgical tool mount 124 to the actuation assembly 102 to hold or guide additional surgical instruments.

[0172] It will also be understood that a method of manufacturing the expandable access port 100 is also encompassed by the present disclosure. For example, the expandable access port 100 may be manufactured by the following steps. That is, providing an actuating assembly 102 that defines an actuating assembly opening 102a surrounding the longitudinal axis 100a, and providing a plurality of actuating arms 116 disposed around the longitudinal axis 100a, each actuating arm 116 being in the distal direction D from each proximal arm end 116g to each distal arm end 116d, each distal arm end 116d being in the actuating assembly 102, each distal arm end 116d being movably coupled to the actuating assembly 102, and when the actuating assembly 102 operates, each distal arm end 116d is movable between a first position where it is spaced from the longitudinal axis 100a by a first distance D1 and a second position where each distal arm end 116d is spaced from the longitudinal axis 100a by a second distance D1, each second distance D2 being greater than each first distance D1, and overmolding a membrane 118 onto the plurality of actuating arms 116, the membrane 118 extending in the distal direction D from a proximal membrane end 118a adjacent to the actuating assembly 102 to a distal membrane end 118b adjacent to each distal arm end 116d, the membrane 118 being made of a flexible material that is expandable to allow the plurality of actuating arms 116 to move from each first position to each second position. Any steps for this method include forming the membrane 118 from a material as described above and having dimensions and other properties, sizing the membrane 118 formed on the actuating arms 116, placing a light 120 in the slot 116e, shaping the membrane 118 into a structure consisting of ribs 118d on the outer radial surface 116h of the actuating arms 116 and walls 118e between each adjacent pair of ribs 118d, and sizing a lip 118c around the distal arm ends 116d, but are not limited thereto.

[0173] The various parts of the expandable access port are suitable for the purposes of this specification and may be made from any material having suitable biocompatibility for use in a surgical environment. For example, the actuating arm 116 and the membrane 118 of the expandable port 104 may be configured as described above and may be transparent or translucent to enable visualization of the brain tissue surrounding the expandable port 104. Similarly, the introducer 106, the port housing 108, the locking ring 110, the actuating ring 112, and the actuating ring cover 114 may be constructed of polycarbonate or other materials and may be transparent or opaque.

[0174] The present disclosure provides some exemplary embodiments of the invention as defined by the appended claims. The description of such embodiments is not intended to limit the claims beyond what is defined in the claims. While embodiments may provide certain advantages in certain instances, it will be understood that the claims are not limited to embodiments that provide any particular advantage or function. Further, other embodiments encompassed by the claims may depart from those described herein in both appearance and function, and it will be understood that the various features of the specific embodiments described herein may be used in other embodiments without departing from the claims.

Claims

1. An expandable surgical access port, comprising: An actuation assembly defining an actuation assembly opening surrounding a longitudinal axis, the actuation assembly comprising: An actuation arm mounting body defining an actuation arm mounting body opening surrounding at least a portion of the actuation assembly opening, the actuation arm mounting body having a plurality of pivot positions surrounding the longitudinal axis, each pivot position defining a respective pivot axis extending in a plane perpendicular to the longitudinal axis and not intersecting the longitudinal axis; an actuation arm mounting body; and an actuation ring attached to the actuation arm mounting body and defining an actuation ring opening surrounding at least a portion of the actuation assembly opening, the actuation ring being rotatable about the longitudinal axis relative to the actuation arm mounting body so as to rotate between a first actuation ring position and a second actuation ring position, the actuation ring remaining at a fixed position along the longitudinal axis over the entire range of movement between the first actuation ring position and the second actuation ring position; an actuation ring; A plurality of actuation arms disposed around the longitudinal axis, each actuation arm extending distally from a respective proximal arm end to a respective distal arm end, each proximal arm end being pivotally coupled to the actuation assembly at a respective one of the plurality of pivot positions, each actuation arm being pivotable about a respective pivot axis between a respective first arm position in which each distal arm end is spaced from the longitudinal axis by a respective first distance and a respective second arm position in which each distal arm end is spaced from the longitudinal axis by a respective second distance when the actuation ring moves from the first actuation ring position to the second actuation ring position, each second distance being greater than each first distance; a plurality of actuation arms; A membrane surrounding the plurality of actuation arms and extending from a proximal membrane end adjacent to the actuation assembly to a distal membrane end, the membrane comprising a flexible material that is expandable to allow the plurality of actuation arms to move from respective first positions to respective second positions; a membrane; An expandable surgical access port comprising the above components.

2. The actuation arm mounting body is Define a port housing opening that surrounds at least a portion of the actuation assembly opening and has a plurality of first pivot recesses, a port housing, Define a lock ring opening that surrounds at least a portion of the actuation assembly opening and has a plurality of second pivot recesses, a lock ring, and comprises: The lock ring is fixed to the port housing with each of the first pivot recesses adjacent to one of each of the second pivot recesses, defining one of each of the pivot positions. The expandable surgical access port of claim 1.

3. The actuation ring is attached to the port housing by a rotatable coupling. The expandable surgical access port according to claim 2.

4. The rotatable coupling has a plurality of sliding tabs and corresponding sliding tab receiving portions. The expandable surgical access port according to claim 3.

5. Each pivot position comprises an actuation arm port that extends in the distal direction along the longitudinal axis from each of the respective pivot axes, and each actuation arm is movable within at least a portion of each actuation arm port. The expandable surgical access port according to claim 1.

6. The actuation ring is rotatable in a first direction to actuate the actuation arms from each of the first arm positions to each of the second arm positions, and rotatable in a second direction to actuate the actuation arms from each of the second arm positions to each of the first arm positions. The expandable surgical access port according to claim 1.

7. The actuation ring comprises a plurality of cam slots, each cam slot extending around a portion of the actuation ring opening from each of the first cam slot ends to each of the second cam slot ends, and each of the second cam slot ends is closer to the longitudinal axis than each of the first cam slot ends. The expandable surgical access port according to claim 6.

8. Each actuation arm has each of the respective pivots and each of the cam followers that extend proximally from each of the respective pivots to one of each of the plurality of cam slots. The rotation of the actuating ring from the first actuating ring position to the second actuating ring position moves each cam follower from each first cam slot end to each second cam slot end, thereby moving each actuating arm from each first arm position to each second arm position, the expandable surgical access port according to claim 7.

9. Each pivot position has each cam follower port extending in the proximal direction opposite to the distal direction along the longitudinal axis from each of the respective pivot axes, and each cam follower extends through one of each of the cam follower ports, the expandable surgical access port according to claim 8.

10. The actuating ring has a tapered inlet surface with a decreasing diameter in the distal direction, the expandable surgical access port according to claim 1.

11. Each actuating arm has each pivot located at each of the respective proximal arm ends and rotatably fixing one of each of the pivot positions, and each linear elongated body extending from each of the respective pivots to each of the respective distal arm ends, and each distal arm end of each actuating arm has an inward bend towards the longitudinal axis, the expandable surgical access port according to claim 1.

12. At least one of the plurality of actuating arms includes each light located at each of the respective distal arm ends, the expandable surgical access port according to claim 1.

13. The at least one actuating arm has each slot extending at least partially from the proximal slot end to the distal slot end between each of the respective proximal arm ends and each of the respective distal arm ends, and each of the lights is located at each of the respective distal slot ends, the expandable surgical access port according to claim 12.

14. The at least one actuating arm includes one of a light guide and an electric wire extending along the slot from the proximal slot end to the light, the expandable surgical access port according to claim 13.

15. The proximal slot end is at each of the respective pivots of each of the actuating arms, the expandable surgical access port according to claim 14.

16. The expandable surgical access port according to claim 13, wherein each of the slots is located on a radially outer surface of each of the respective actuating arms.

17. The expandable surgical access port according to claim 1, wherein each pivot axis is in contact with the longitudinal axis.

18. The expandable surgical access port according to claim 1, wherein the actuating ring is disposed proximal to the actuating arm attachment body.

19. The expandable surgical access port according to claim 1, wherein the actuating ring has an outer surface defining a gripping portion, and each diameter of the gripping portion is larger than each diameter of an adjacent portion of the actuating arm attachment body.

20. The expandable surgical access port according to claim 1, wherein the actuating ring has an outer surface having a knurling.

21. The expandable surgical access port according to claim 1, wherein the actuating ring attachment body further comprises one or more extensions disposed proximal to or in the vicinity of the proximal side of the actuating ring.

22. The expandable surgical access port according to claim 1, wherein the actuating ring attachment body further comprises one or more extensions configured to couple to one or more of a clamp, a navigation device, and a surgical tool mount.

23. The expandable surgical access port according to claim 1, further comprising a position indicator configured to identify a position of the actuating ring relative to the actuating arm attachment body.

24. The actuating arm attachment body has one or more body position indicators, and the actuating ring has one or more ring position indicators, The expandable surgical access port according to claim 1, wherein the one or more body position indicators and the one or more ring position indicators are aligned when the actuating ring is in one or more predetermined positions relative to the actuating arm attachment body.

25. The expandable surgical access port according to claim 1, wherein the actuating ring has an outer surface defining a gripping portion, and each diameter of the gripping portion is larger than each diameter of an adjacent portion of the actuating arm attachment body.

26. The expandable surgical access port according to claim 1, further comprising depth markers spaced along the longitudinal axis and visible on or through the membrane.

27. The expandable surgical access port according to claim 1, further comprising a surgical tool mount configured to be fixed to the actuating arm attachment body, the surgical tool mount A ring-shaped mounting body defining a circular opening, A ring-shaped connector mounted within the opening and configured to rotate about the central axis of the circular opening, the ring-shaped connector having a tool lock offset radially from the central axis of the circular opening, The expandable surgical access port according to claim 1, comprising:

28. The expandable surgical access port according to claim 27, wherein the ring-shaped connector is freely rotatable about at least a portion of the central axis of the circular opening and does not include a rotation lock.

29. An expandable surgical access port, An actuating assembly defining an actuating assembly opening surrounding a longitudinal axis, A plurality of actuating arms disposed around the longitudinal axis and movably attached to the actuating assembly, each actuating arm having an elongated body extending distally from the actuating assembly to each distal arm end, A flexible membrane surrounding the plurality of actuating arms and extending from a proximal membrane end adjacent to the actuating assembly to a distal membrane end adjacent to each distal arm end, At least one actuating arm, The actuating assembly and each slot extending between each distal arm end from a proximal slot end to a distal slot end, The expandable surgical access port having each light located at each distal slot end.

30. The expandable surgical access port according to claim 29, further comprising an optical connector extending along the slot from the proximal slot end to the light.

31. The expandable surgical access port according to claim 30, wherein the optical connector comprises at least one of a light guide and an electric wire.

32. The expandable surgical access port according to claim 30, wherein the proximal slot end is at each pivot joining each actuating arm to the actuating assembly.

33. The expandable surgical access port according to claim 30, wherein the actuating assembly has a housing internal space configured to receive a portion of the optical connector, and the proximal slot end is open to the housing internal space.

34. The actuating assembly, An operating arm mounting body that defines an operating arm mounting body opening surrounding at least a portion of the operating assembly opening, the operating arm mounting body comprising a plurality of pivot positions surrounding the longitudinal axis, each pivot position defining a respective pivot axis that is perpendicular to the longitudinal axis and extends within a plane that does not intersect the longitudinal axis, the operating arm mounting body and, An operating ring attached to the operating arm mounting body and defining an operating ring opening surrounding at least a portion of the operating assembly opening, the operating ring being rotatable about the longitudinal axis relative to the operating arm mounting body so as to rotate between a first operating ring position and a second operating ring position, the operating ring and, Each of the plurality of operating arms is pivotally coupled to the operating assembly at one of the plurality of pivot positions, each operating arm being pivotable about each respective pivot axis from each first arm position where each distal arm end is spaced from the longitudinal axis by each first distance and each second arm position where each distal arm end is spaced from the longitudinal axis by each second distance when the operating ring moves from the first operating ring position to the second operating ring position, each second distance being greater than each first distance, the expandable surgical access port according to claim 33.

35. The expandable surgical access port according to claim 36, wherein the proximal slot end is at each pivot that couples each respective operating arm to each respective pivot position.

36. The expandable surgical access port according to claim 36, wherein the operating ring remains in a fixed position along the longitudinal axis over the entire range of movement between the first operating ring position and the second operating ring position.

37. The operating arm mounting body is A port housing that defines a port housing opening surrounding at least a portion of the operating assembly opening, A connector housing that defines a connector housing opening surrounding at least a portion of the operating assembly opening, adjacent to the port housing, and defining an internal housing space between the connector housing and the port housing, the connector housing and, A lock ring that defines a lock ring opening surrounding at least a portion of the operating assembly opening, The expandable surgical access port according to claim 36, having **Claim 38** The expandable surgical access port according to claim 37, wherein the locking ring is fixed to the connector housing with at least a portion of the port housing captured between the locking ring and the connector housing. **Claim 39** The expandable surgical access port according to claim 38, further comprising a plurality of locking tabs extending into the portion of the port housing captured between the locking ring and the connector housing, and a plurality of locking tab receivers configured to engage the plurality of locking tabs. **Claim 40** The expandable surgical access port according to claim 37, wherein the plurality of pivot positions are defined between the locking ring and the port housing. **Claim 41** The expandable surgical access port according to claim 33, wherein the internal space of the actuation assembly housing comprises a portion that extends radially from the longitudinal axis and opens in a proximal direction opposite the distal direction. **Claim 42** The expandable surgical access port according to claim 49, wherein each slot is located on a respective radially outer surface of each actuation arm. **Claim 43** The expandable surgical access port according to claim 41, wherein the flexible membrane surrounds each respective outer radial surface and each respective slot. **Claim 44** The expandable surgical access port according to claim 43, wherein the flexible membrane is shaped to a predetermined position. **Claim 45** An expandable surgical access port, comprising: a plurality of actuation assemblies defining an actuation assembly opening surrounding a longitudinal axis; a plurality of actuation arms disposed around the longitudinal axis, each actuation arm extending distally from each respective proximal arm end to each respective distal arm end, each respective proximal arm end being movably coupled to the actuation assembly, and each respective distal arm end being movable between a first position in which each is spaced from the longitudinal axis by a first distance and a second position in which each is spaced from the longitudinal axis by a second distance during operation of the actuation assembly, each second distance being greater than each first distance. A membrane that surrounds a plurality of actuating arms and extends distally from a proximal membrane end adjacent to the actuating assembly to a distal membrane end adjacent to each distal arm end, the membrane being overmolded on the plurality of actuating arms and including a flexible material that is expandable to enable the plurality of actuating arms to move from each respective first position to each respective second position. An expandable surgical access port comprising the same. **Claim 46** The expandable surgical access port according to claim 45, wherein the membrane comprises a thermoplastic elastomer. **Claim 47** The expandable surgical access port according to claim 45, wherein the membrane comprises an elastomer based on styrene-based olefin rubber and hydrogenated isoprene, containing polypropylene as a reinforcing agent and mineral oil as a plasticizer and a processing aid. **Claim 48** The expandable surgical access port according to claim 45, wherein the membrane has a wall thickness of 0.06096 cm to 0.02032 cm. **Claim 49** The expandable surgical access port according to claim 45, wherein the membrane has a wall thickness of 0.0508 cm to 0.03048 cm. **Claim 50** The expandable surgical access port according to claim 45, wherein the membrane has a wall thickness of 0.0381 cm to 0.04318 cm. **Claim 51** The expandable surgical access port according to claim 45, wherein the membrane is expandable up to at least 250% at the distal membrane end. **Claim 52** The expandable surgical access port according to claim 45, wherein the membrane is expandable up to at least 300% at the distal membrane end. **Claim 53** The expandable surgical access port according to claim 45, wherein the membrane is expandable up to at least 350% at the distal membrane end. **Claim 54** The expandable surgical access port according to claim 45, wherein the membrane is expandable at the distal membrane end from a diameter of 1.016 cm or less to a diameter of 2.032 cm or more. **Claim 55** The expandable surgical access port according to claim 45, wherein the membrane is expandable at the distal membrane end from a diameter of 0.762 cm or less to a diameter of 2.286 cm or more. **Claim 56** The expandable surgical access port according to claim 45, wherein the membrane is expandable at the distal membrane end from a diameter of 0.635 cm or less to a diameter of 2.54 cm or more. **Claim 57** The membrane has each rib located on the outer radial surface of each operating arm and each wall extending between each adjacent pair of ribs, of the expandable surgical access port according to claim 45.

58. The expandable surgical access port according to claim 45, wherein the membrane has a lip that wraps around each distal arm end.

59. Each operating arm has each outer radial surface, and each outer radial surface has each slot that at least partially extends between each proximal arm end and each distal arm end, and each portion of the overmolded flexible material membrane extends into each slot, of the expandable surgical access port according to claim 45.

60. The expandable surgical access port according to claim 59, wherein at least one of each of the slots comprises a light received between each of the slots and each of the portions of the overmolded flexible material membrane.

61. A method for manufacturing an expandable surgical access port, The method comprises: providing an operating assembly that defines an operating assembly opening surrounding a longitudinal axis; providing a plurality of operating arms disposed around the longitudinal axis, each operating arm extending distally from each proximal arm end to each distal arm end, each proximal arm end being movably coupled to the operating assembly, and each distal arm end being movable between each first position spaced from the longitudinal axis by each first distance and each second position spaced from the longitudinal axis by each second distance during operation of the operating assembly, and each second distance being greater than each first distance; overmolding a membrane onto the plurality of operating arms, the membrane extending distally from a proximal membrane end adjacent to the operating assembly to a distal membrane end adjacent to each distal arm end, the membrane comprising a flexible material that is expandable to allow the plurality of operating arms to move from each of the first positions to each of the second positions.

62. The method according to claim 61, wherein the membrane comprises a thermoplastic elastomer.

63. The method according to claim 61, wherein the film contains polypropylene as a reinforcing agent and mineral oil as a plasticizer and a processing aid, and comprises an elastomer based on styrene-based olefin rubber and hydrogenated isoprene.

64. The method according to claim 61, wherein the film has a wall thickness of from 0.06096 cm to 0.02032 cm.

65. The method according to claim 61, wherein the film has a wall thickness of from 0.0508 cm to 0.03048 cm.

66. The method according to claim 61, wherein the film has a wall thickness of from 0.0381 cm to 0.04318 cm.

67. The method according to claim 61, wherein the film is expandable at least up to 250% at the distal film end.

68. The method according to claim 61, wherein the film is expandable at least up to 300% at the distal film end.

69. The method according to claim 61, wherein the film is expandable at least up to 350% at the distal film end.

70. The method according to claim 61, wherein the film is expandable at the distal film end from a diameter of 1.016 cm or less to a diameter of 2.032 cm or more.

71. The method according to claim 61, wherein the film is expandable at the distal film end from a diameter of 0.762 cm or less to a diameter of 2.286 cm or more.

72. The method according to claim 61, wherein the film is expandable at the distal film end from a diameter of 0.635 cm or less to a diameter of 2.54 cm or more.

73. Each actuating arm has each outer radial surface, and the step of overmolding the film onto the plurality of actuating arms comprises overmolding the film onto each outer radial surface of each actuating arm, the method according to claim 61.

74. Each actuating arm has each slot extending at least partially along each of the respective outer radial surfaces, and the step of overmolding the film comprises overmolding each portion of the film material into each slot, the method according to claim 73.

75. Each of the at least one slot has a light, and the step of overmolding the film comprises accommodating the light between each of the slots and the film, the method according to claim 74.

76. The step of overmolding the membrane comprises forming each rib located on the outer radial surface of each actuating arm and each wall extending between each adjacent pair of ribs, the method according to claim 61.

77. The step of overmolding the membrane comprises overmolding a lip that wraps around each distal arm end, the method according to claim 61.

78. An expandable surgical access port assembly comprising an actuating assembly defining an actuating assembly opening surrounding a longitudinal axis; a plurality of actuating arms arranged around the longitudinal axis, each actuating arm extending distally from each proximal arm end of the actuating assembly to each distal arm end, each proximal arm end being between a first position where each distal arm end is spaced from the longitudinal axis by each minimum distance and a second position where each distal arm end is spaced from the longitudinal axis by each maximum distance, being movable during operation of the actuating assembly, each maximum distance being greater than each minimum distance, a plurality of actuating arms; a membrane surrounding the plurality of actuating arms and extending distally from a proximal membrane end adjacent to the actuating assembly to a distal membrane end, the membrane being expandable to allow the plurality of actuating arms to move from each of the first positions to each of the second positions; an introducer extending from a proximal introducer end to a distal introducer end, a tubular wall defining a cannula extending into the introducer from the proximal introducer end to a point adjacent to the distal introducer end; an introducer tip located at the distal introducer end, the introducer tip being tapered so as to increase in size proximally to a first introducer diameter; an outer annular recess located proximally to the introducer tip and having a region with a second introducer diameter, the second introducer diameter being smaller than the first introducer diameter, the introducer having; comprising the introducer is selectively insertable through the actuating assembly opening and is coupled to the actuating assembly in an actuated position, the cannula is arranged along the longitudinal axis, and the introducer tip extends distally beyond each distal arm end. The introducer is in the operative position, the plurality of actuating arms are in their respective first positions, and at least a portion of each distal arm end is disposed within the outer annular recess. Expandable surgical access port assembly. **Claim 79** The expandable surgical access port assembly of claim 78, wherein each actuating arm has a respective pivot located at each respective proximal arm end and rotatably fixed to the actuating ring assembly at each pivot location. **Claim 80** The expandable surgical access port assembly of claim 79, wherein each actuating arm is configured to pivot about a respective pivot axis, and each pivot axis is in contact with the longitudinal axis. **Claim 81** The expandable surgical access port assembly of claim 80, wherein each actuating arm comprises a respective straight, elongated body extending from each respective pivot to each respective distal arm end. **Claim 82** The expandable surgical access port assembly of claim 78, wherein each distal arm end of each actuating arm has an inner bend toward the longitudinal axis, and each inward bend is positioned within the outer annular recess when the plurality of actuating arms are in their respective first positions. **Claim 83** The expandable surgical access port assembly of claim 78, wherein with the introducer in the operative position and the plurality of actuating arms in their respective first positions, the introducer tip and the plurality of actuating arms or the membrane form a continuous, tapered outer wall. **Claim 84** The expandable surgical access port assembly of claim 78, wherein the introducer cannula terminates at the distal introducer end in a probe tip receiving portion configured to hold one or more different navigation probe tips. **Claim 85** The actuating assembly has an inner surface surrounding the actuating assembly opening. The introducer has an outer surface. The expandable surgical access port assembly of claim 78, wherein when the introducer is in the operative position, the outer surface contacts the inner surface and prevents movement of the outer surface in a direction perpendicular to the longitudinal axis. **Claim 86** The expandable surgical access port assembly of claim 85, wherein at least one of the inner surface and the outer surface is tapered such that the diameter decreases in the distal direction. **Claim 87** The expandable surgical access port assembly of claim 85, wherein the inner surface and the outer surface are tapered such that the diameter decreases in the distal direction.

88. The expandable surgical access port assembly of claim 85, wherein the inner surface and the outer surface each have a respective conical surface.

89. The expandable surgical access port assembly of claim 88, wherein the respective conical surfaces of the inner surface and the outer surface have respective matching taper angles.

90. The expandable surgical access port assembly of claim 78, wherein the actuation assembly has a plurality of position indicators configured to indicate when the plurality of actuation arms are in at least one of the respective first positions and the respective second positions.

91. The expandable surgical access port assembly of claim 78, wherein the actuation assembly comprises a plurality of position indicators configured to indicate when the plurality of actuation arms are in respective intermediate positions between the respective first positions and the respective second positions.

92. The expandable surgical access port assembly of claim 91, wherein each of the respective intermediate positions comprises a position at which the plurality of distal arm ends are spaced apart by the diameter of the first introducer.

Images