Patent Description:
In order to facilitate minimally invasive surgery, a working space must be created at a surgical site. An insufflation fluid, typically CO<NUM>, is introduced into the abdomen of the patient to create an inflated state called pneumoperitoneum. Surgical access assemblies are utilized to allow the introduction of surgical instrumentation and endoscopes (or other visualization tools). These surgical access assemblies maintain the pressure for the pneumoperitoneum, as they have one or more seals that adapt to the surgical instrumentation. Typically, a "zero-seal" in the surgical access assembly seals the surgical access assembly in the absence of a surgical instrument in the surgical access assembly, and an instrument seal seals around a surgical instrument that has been inserted through the surgical access assembly.

The breadth of surgical instrumentation on the market today requires a robust seal capable adjusting to multiple sizes and withstanding multiple insertions and withdrawals of surgical instrumentation. Some of the surgical instrumentation can include sharp edges that can tear or otherwise damage seals. Therefore, it would be beneficial to have an access assembly with improved seal durability.

<CIT> describes surgical access assemblies according to the preamble of claim <NUM>. <CIT> describes further surgical access assemblies that include an instrument seal.

In accordance with the present invention, a surgical access assembly has a housing, a tubular member extending from the housing, and a valve assembly disposed in the housing. The valve assembly includes a guard assembly with a central orifice and an instrument seal having a central hole aligned with the central orifice of the guard assembly. The instrument seal includes a frame formed of a plurality of segments, each segment having a top surface and a bottom surface and having respective petals that are flexibly coupled to a side thereof by a living hinge. The instrument seal has an unfolded configuration defined by the petals extending away from a center of the frame and a folded configuration defined by the petals folded towards the central hole of the instrument seal such that each petal at least partially overlaps an adjacent petal such that the petals interlock. Each petal is attached to the corresponding segment of the frame via the living hinge such that each petal and the corresponding living hinge define an acute angle with respect to either the top surface or the bottom surface of the segment of the frame.

The folded configuration of the instrument seal may define a diameter of the central hole that is configured to seal against a surgical instrument.

The folded configuration of the instrument seal may allow the petals to flex relative to the frame while the frame remains axially stationary relative to the housing.

The valve assembly may include a centering mechanism with a central opening, wherein the guard assembly is disposed on a first side of the centering mechanism and the instrument seal is disposed on a second side of the centering mechanism that is opposite the first side.

In these embodiments, the valve assembly may also include a retainer with first and second rings. The first ring may be disposed on the first side of the centering mechanism and the second ring may be disposed on the second side of the centering mechanism. The retainer may sandwich the centering mechanism between the guard assembly and the instrument seal.

The first ring of the retainer may include pins and the second ring of the retainer may include openings for receiving the pins. The pins of the first ring may be insertable through bores of the guard assembly, pores of the centering mechanism, and holes of the instrument seal to maintain the guard assembly, the centering mechanism, and the instrument seal in an aligned relationship.

Embodiments of a surgical access assembly according to the invention incorporating an instrument seal are disclosed herein with reference to the drawings, wherein:.

Embodiments of the presently disclosed surgical access assembly will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term "proximal" refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term "distal" refers to that part or component farther away from the user.

Surgical access assemblies are employed during minimally invasive surgery, e.g., laparoscopic surgery, and provide for the sealed access of surgical instruments into an insufflated body cavity, such as the abdominal cavity. The surgical access assemblies of the present disclosure include an instrument valve housing mounted on a cannula tube, and include an obturator (not shown) inserted through the instrument valve housing and cannula tube. The obturator can have a blunt distal end, or a bladed or non-bladed penetrating distal end and can be used to incise the abdominal wall so that the surgical access assembly can be introduced into the abdomen. The handle of the obturator can engage or selectively lock into the instrument valve housing of the surgical access assembly.

Surgical access assemblies with a trocar obturator are employed to tunnel through an anatomical structure, e.g., the abdominal wall, either by making a new passage through the structure or by passing through an existing opening through the anatomical structure. Once the surgical access assembly with the trocar has tunneled through the anatomical structure, the trocar obturator is removed, leaving the surgical access assembly in place. The instrument valve housing of the surgical access assembly includes valves that prevent the escape of insufflation fluid from the body cavity, while also allowing surgical instruments to be inserted into the cavity and minimizing the escape of insufflation fluid.

In various embodiments, a bladeless optical trocar obturator may be provided that permits separation of tissue planes in a surgical procedure and visualization of body tissue fibers as they are being separated, thereby permitting a controlled traversal across a body wall. In other embodiments, the trocar obturator may be bladeless without being optical, e.g., without providing contemporaneous visualization thereof through the distal tip of the obturator. The bladeless obturator may be provided for the blunt dissection of the abdominal lining during a surgical procedure.

Various trocar obturators suitable for use with the surgical access assemblies of the present disclosure are known and include, for example, bladed, bladeless, blunt, optical, and non-optical. For a detailed description of the structure and function of exemplary trocar assemblies, including exemplar trocar obturators and exemplar cannulas, please refer to <CIT> ("the '<NUM> publication").

With initial reference now to <FIG>, a surgical access assembly according to aspects of the present invention is shown generally as cannula assembly <NUM>. The cannula assembly <NUM> includes a cannula <NUM> and an instrument valve housing <NUM> secured to the cannula <NUM>. For a detailed description of an exemplary cannula assembly, please refer to the '<NUM> publication.

With additional reference to <FIG>, the instrument valve housing <NUM> of the cannula assembly <NUM> includes an upper housing section <NUM>, a lower housing section <NUM>, and an inner housing section <NUM>. The upper, lower, and inner housing sections <NUM>, <NUM>, <NUM> are configured to support a valve assembly <NUM> on a proximal end of the cannula <NUM>. More particularly, the inner housing section <NUM> is secured between the upper and lower housing sections <NUM>, <NUM>, and the valve assembly <NUM> is received between the inner and lower housing sections <NUM>, <NUM>. The upper and lower housing sections <NUM>, <NUM> of the instrument valve housing <NUM> may be selectively attachable to, and detachable from, the inner housing section <NUM>. The lower housing section <NUM> may be releasably or permanently attached to a cannula tube <NUM> of the cannula assembly <NUM>. In embodiments, either or both of the upper and lower housing sections <NUM>, <NUM> of the instrument valve housing <NUM> may include knurls, indentations, tabs, or be otherwise configured to facilitate engagement by a clinician.

The cannula assembly <NUM> may also include features for the stabilization of the surgical access assembly. For example, the distal end of the cannula tube <NUM> can carry a balloon anchor or another expandable member that engages the abdomen from the interior side. For example, see <CIT>. A feature on the opposite side of the abdominal wall can be used to further stabilize the surgical access assembly, such as adhesive tabs or adjustable foam collars.

The upper, lower, and inner housing sections <NUM>, <NUM>, <NUM> of the instrument valve housing <NUM> define a longitudinal passage <NUM> for receipt of a surgical instrument (not shown). The valve assembly <NUM> is supported within the instrument valve housing <NUM> to provide sealed passage of the surgical instrument through the cannula assembly <NUM>.

Referring now to <FIG>, an instrument seal <NUM>, according to an embodiment of the present invention, is illustrated. The instrument seal <NUM>, as illustrated, includes a hexagonal frame <NUM> that may be integrally formed (i.e., monolithic or unitary) or may be formed from six discrete segments that are joined together to form the frame <NUM>. The segments may be joined to each other by welding, adhesives, mechanical joints, or other techniques as known in the art. The sides or segments 172a-f of the frame <NUM> form a boundary that defines a passage <NUM> having a center through the instrument seal <NUM>. The center of the passage <NUM> is coaxial with a central hole <NUM> of the instrument seal <NUM>. A corresponding number of petals <NUM> are attached to the frame <NUM>. Although depicted with six petals 162a-f coupled to a hexagonal frame <NUM>, the instrument seal may include a frame with more sides or discrete segments and a corresponding number of petals (e.g., <NUM>). Alternatively, the presently disclosed instrument seal may include a frame with fewer sides or discrete segments and a corresponding number of petals (e.g., <NUM>). The frame <NUM> and the petals 162a-f may be fabricated from a polyisoprene, a liquid silicone rubber, or another suitable polymeric material. The instrument seal <NUM> may be molded, stamped, or formed in any other suitable manner. Each petal 162a-f is flexibly coupled to a side 172a-f of the frame <NUM> via a living hinge 174a-f. Further, as shown in <FIG> and <FIG>, each petal 162a-f is attached to the corresponding side 172a-f of the frame <NUM> via the living hinge 174a-f such that each petal 162a-f and the corresponding living hinge 174a-f define an acute angle with respect to either a top or bottom surface of the side or segment of the frame <NUM>. The acute angle may be in the range of about <NUM>° to about <NUM>°. By angling each petal 162a-f relative to the top or bottom surface of the frame <NUM>, interweaving the petals 162a-f of the instrument seal <NUM> is easier than if each petal 162a-f was parallel with the top or bottom surface of the frame <NUM>.

Each petal 162a-f is a five sided main panel 150a-f with holes168 extending therethrough. Although shown with five sides, each main panel 150a-f may have more or less than five sides. A first or connection side 161a-f is coupled to a side or segment 172a-f of the frame <NUM> with the corresponding living hinge 174a-f. This arrangement allows the petal 162a-f to be transitioned from an unfolded configuration (<FIG>) to a folded configuration (<FIG>). Each living hinge 174a-f may be formed from the same material as the frame <NUM> and the petals162a-f or may be formed from another suitable polymeric material. In the unfolded configuration, each petal 162a-f extends away from an outer surface of the frame <NUM> outside a perimeter defined by the frame <NUM>. In the folded configuration, each petal 162a-f is bounded by the frame <NUM> and is within the perimeter defined by the frame <NUM>. Each main panel 150a-f has angled second and third sides 163a-f, 165a-fthat extend from the connection side 161a-f in a divergent manner. Fourth and fifth sides 167a-f, 169a-f of main panels 150a-f interconnect the angled second and third sides 163a-f, 165a-f. The fourth and fifth sides 167a-f, 169a-f of the main panels 150a-f of each petal 162a-f have equal lengths and are angled towards the corresponding connection side 161a-f such that they meet a point that would bisect the connection side 161a-f. Additionally, the fourth and fifth sides 167a-f, 169a-f are oriented such that they define an angle between <NUM>° and <NUM>°. First and second extenders 164a-f, 166a-f are attached to the fourth and fifth sides 167a-f, 169a-f. Each extender 164a-f, 166a-f includes a hole <NUM> extending therethrough. The first and second extenders 164a-f, 166a-f have equal lengths and meet at wedges 173a-f that also is located at a point that would bisect the connection side 161a-f. The extenders 164a-f, 166a-f and the main panels 150a-f of each petal 162a-fbend at a midpoint between the second and third sides 163a-f, 165a-f of each petal 162a-f such that, when viewed from the end (i.e., from the extenders towards the connection side) (see <FIG>), the petal 162a-f has a slight curvature of about <NUM>° to about <NUM>°. The combination of the petals' 162a-f curvature, the angled relationship between each petal 162a-f and the side or segment 172a-f of the frame <NUM>, and the material of construction, facilitates folding the petals 162a-f in an interlocking pattern when transitioning the instrument seal <NUM> from the unfolded configuration to the folded configuration.

With reference now to <FIG>, <FIG>, transitioning the instrument seal <NUM> from the unfolded configuration (<FIG>) to the folded configuration (<FIG>) includes folding the petals 162a-f sequentially such that they interlock by having each petal 162a-f partially overlap an adjacent petal 162a-f. Initially, as seen in <FIG>, the instrument seal <NUM> is in the unfolded configuration with the extenders 164a-f, 166a-f of the petals 162a-f facing away from the frame <NUM>. Each petal 162a-f is folded along a line defined by the associated living hinge 174a-f which defines an angle between the connection side 161a-f of the respective petal 162a-f and the corresponding side or segment 172a-f of the frame <NUM>. Thus, the intersection of the connection side 161a-f and the corresponding third side 165a-f of each petal 162a-f is closer to the side or segment 172a-f of the frame <NUM> than the intersection of the connection side 161a-f and the second side 163a-f of each petal 162a-f is to the side or segment 172a-f of the frame <NUM>. The petals 162a-f are folded sequentially in the direction of arrows "A" such that all of the petals 162a-f are in a near vertical orientation (<FIG>). In this arrangement, the second side 163a-f of one petal 162a-f partially overlaps the third side 165a-f of the adjacent petal 162a-f. In particular, as illustrated in <FIG>, the third side 165a of the first petal 162a partially overlaps the second side 163f of the sixth petal 162f, the third side 165b of the second petal 162b partially overlaps the second side 163a of the first petal 162a, the third side <NUM> of the third petal 162c partially overlaps the second side of the second petal 162b, the third side 165d of the fourth petal 162d partially overlaps the second side 163c of the third petal 162c, the third side 165e of the fifth petal 162e partially overlaps the second side 163d of the fourth petal 162d, the third side 165f of the sixth petal 162f partially overlaps the second side 163e of the fifth petal 162e, and the third side 165a of the first petal 162a partially overlaps the second side 163f of the sixth petal 162f. This defines a partially folded configuration of the instrument seal <NUM>. Subsequently, the user continues to fold the petals 162a-f towards a center of the frame <NUM> in the direction of arrows "A" while maintaining the overlapping arrangement between the second and third sides 163a-f, 165a-f of the petals 162a-f. Once all the petals 162a-f are folded such that they are substantially flush with a top surface of the frame <NUM>, the overlapping arrangement of the second and third sides 163a-f, 165a-f of the petals 162a-f maintains the petals 162a-f in contact with one another thereby maintaining the instrument seal <NUM> in the folded configuration. Further, once all the petals 162a-f are folded over, the holes <NUM> of the petals 162a-f are aligned thereby allowing pins <NUM> of a retainer <NUM> to pass therethrough as will be discussed in detail hereinbelow. As seen in <FIG>, the folded configuration of the instrument seal <NUM> defines a central hole <NUM> for slidably receiving a surgical instrument therethrough. The central hole <NUM> may have a diameter between <NUM> inches to <NUM> inches (i.e., <NUM> to <NUM>).

With reference now to <FIG>, <FIG>, the valve assembly <NUM>, according to an embodiment of the present disclosure, is illustrated. The valve assembly <NUM> is located in the instrument valve housing <NUM> and includes a centering mechanism <NUM>, a guard assembly <NUM>, the instrument seal <NUM>, and a retainer <NUM>. The centering mechanism <NUM> of the valve assembly <NUM> permits radial movement of the valve assembly <NUM> relative to a central longitudinal axis "X" of the instrument valve housing <NUM> in response to insertion of a surgical instrument (not shown) through the valve assembly <NUM> and radial movement of the surgical instrument relative to the central longitudinal axis "X". In the absence of a surgical instrument or in the absence of radial movement of a surgical instrument relative to the central longitudinal axis "X", the centering mechanism <NUM>, as will be described in detail hereinbelow, returns the valve assembly <NUM> to a generally centered position such that a central opening <NUM> of the centering mechanism <NUM> and the central longitudinal axis "X" are coaxial. The guard assembly <NUM> protects the instrument seal <NUM> during insertion and withdrawal of a surgical instrument through the instrument seal <NUM>, which, as discussed hereinabove, provides for sealed passage of the surgical instrument through the instrument valve housing <NUM>. The retainer <NUM> includes first and second rings <NUM>, <NUM> that are located on opposing sides of the centering mechanism <NUM> for maintaining relative positions of the guard assembly <NUM>, the centering mechanism <NUM>, and the instrument seal <NUM>. Additionally, the retainer maintains <NUM> an aligned relationship of the guard assembly <NUM>, the centering mechanism <NUM>, and the instrument seal <NUM>. In particular, the first ring <NUM> of the retainer <NUM> includes pins <NUM> that extend from a bottom surface of the first ring <NUM> while the second ring <NUM> of the retainer <NUM> includes complementary openings <NUM> for receiving the pins <NUM> of the first ring <NUM>. The pins <NUM> may be releasably engaged with the openings <NUM> or the pins <NUM> may be secured within the openings <NUM> by welding, adhesives, friction fit, or other techniques as are known in the art. The pins <NUM> are insertable through bores <NUM> of the guard assembly <NUM>, pores <NUM> of the centering mechanism <NUM>, the holes <NUM> of the instrument seal <NUM>, and the openings <NUM> of the second ring <NUM> of the retainer <NUM>. This arrangement aligns the relative positions of the guard assembly <NUM>, the centering mechanism <NUM>, and the instrument seal <NUM>. Although illustrated with pins <NUM> extending from the first ring <NUM> towards openings <NUM> in the second ring <NUM>, the retainer may have the pins located on the second ring and the openings on the first ring. Alternatively, the first and second rings may have an alternating arrangement of pins and openings that are complementary such that the pins of one of the rings align with openings of the other of the rings allowing the rings to be attached to one another and define the retainer. The first ring <NUM> defines a central opening <NUM> extending therethrough and the second ring <NUM> defines a central opening <NUM> extending therethrough.

The centering mechanism <NUM> of the instrument valve housing <NUM> is configured to maintain the valve assembly <NUM> centered within the instrument valve housing <NUM>. More particularly, the centering mechanism <NUM> includes an outer annular ring <NUM>, an inner annular ring <NUM>, and a bellows <NUM> disposed between the outer annular ring <NUM> and the inner annular ring <NUM>. As shown in <FIG>, the outer annular ring <NUM> is received between the inner housing section <NUM> and the lower housing section <NUM> to retain the centering mechanism <NUM> within the instrument valve housing <NUM>. The inner annular ring <NUM> supports the guard assembly <NUM>. For a detailed description of the structure and function of an exemplary centering mechanism, please refer to <CIT>.

The guard assembly <NUM> may be formed from a sheet of a plastic or other suitable polymeric material by stamping with a tool that forms a ring <NUM> and blades 144a-d. The ring <NUM> surrounds the blades 144a-d and includes bores148 extending therethrough for slidably receiving the pins <NUM> of the first ring <NUM> of the retainer <NUM>. Further, when the valve assembly <NUM> is assembled, the guard assembly <NUM> is positioned between one side of the centering mechanism <NUM> and the first ring <NUM> of the retainer <NUM>. The blades 144a-d are configured to flex towards the centering mechanism <NUM> in response to insertion of a surgical instrument (not shown) through a central orifice <NUM> of the guard assembly <NUM> and return to a generally planar configuration (i.e., parallel with the ring) once the surgical instrument is removed. The blades 144a-d extend towards a center of the ring <NUM> and define the central orifice <NUM> which has a diameter greater than an outside diameter of the surgical instrument.

During a surgical procedure utilizing cannula assembly <NUM>, a surgical instrument (not shown) is introduced into the instrument valve housing <NUM> through the longitudinal passage <NUM> in the upper, lower, and inner housing sections <NUM>, <NUM>, <NUM>. As described above, the distal end of the surgical instrument engages one or more of the blades 144a-d of the guard assembly <NUM> causing the blades 144a-d to flex downward into contact with the petals 162a-f of the instrument seal <NUM>. This causes the central hole <NUM> of the instrument seal <NUM> to dilate such that the diameter of the central hole <NUM> is sufficiently large enough to accommodate passage of the surgical instrument therethrough. The guard assembly <NUM> minimizes damage to the instrument seal <NUM> during insertion and/or removal of the surgical instrument through the valve assembly <NUM>. The guard assembly <NUM> operates to protect the instrument seal <NUM> and minimizes tearing or other damage as the surgical instrument is received through and withdrawn from the instrument seal <NUM>.

With reference now to <FIG>, an alternate embodiment of an instrument seal is illustrated and identified generally as instrument seal <NUM>. Instrument seal <NUM> may be a direct replacement for both the instrument seal <NUM> and the centering mechanism <NUM> in valve assembly <NUM> as illustrated in the previous embodiment. The instrument seal <NUM>, as illustrated, includes a frame <NUM> having six sides 272a-f. The frame <NUM> may have fewer sides (e.g., <NUM>) or more sides (e.g., <NUM>). Each side 272a-f is generally rectangular and extends along a length of a corresponding petal 262a-f. The number of petals <NUM> is equal to the number of sides <NUM> of the frame <NUM>. Links <NUM> extend between adjacent side <NUM> defining a plurality of living hinges. In particular, links <NUM> define living hinges between sides 272a-b, between sides 272b-c, between sides 272c-d, between sides 272d-e, and between sides 272e-f. A gap is defined between sides 272a and 272f allowing sides 272a and 272f to move relative to each other. This arrangement facilitates folding the seal <NUM> thereby transitioning the seal <NUM> from the unfolded or initial configuration as shown in <FIG> to the folded or final configuration as shown in <FIG>. Since sides 272a and 272f have a gap therebetween and lack a living hinge, one of sides 272a or 272f may be repositioned without disturbing the position of the other of sides 272a or 272f. The instrument seal <NUM> also includes a plurality of fins 280a-f that extends from respective sides 272a-f on the side of the side 272a-f opposite that of the petals 262a-f. Each fin 280a-f is a flexible and resilient structure that is normally biased towards a center of the unfolded instrument seal <NUM> (<FIG>) and normally biased away from the center of the folded instrument seal <NUM> (<FIG>). The biasing and resilience of the fins 280a-f acts to center the instrument seal <NUM> when the instrument seal is positioned in the valve housing <NUM> (<FIG>) as will be discussed in further detail hereinbelow.

Each petal 262a-f is a five sided main panel 250a-f with holes <NUM> extending therethrough. Although shown with five sides, each main panel 250a-f may have more or less than five sides. A first or connection side 261a-f is coupled to a side or segment 272a-f of the frame <NUM>. In the unfolded configuration (<FIG> and <FIG>), each petal 262a-f extends away from an outer surface of the frame <NUM> outside a perimeter defined by the frame <NUM>. In the folded configuration (<FIG> and <FIG>), each petal 262a-f is bounded by the frame <NUM> and is within the perimeter defined by the frame <NUM>. Each main panel 250a-f has angled second and third sides 263a-f, 265a-f that extend from the connection side 261a-f in a divergent manner. Fourth and fifth sides 267a-f, 269a-f of main panels 250a-f interconnect the angled second and third sides 263a-f, 265a-f. The fourth and fifth sides 267a-f, 269a-f of the main panels 250a-f of each petal 262a-f have equal lengths and are angled towards the corresponding connection side 261a-f such that they meet a point that would bisect the connection side 261a-f. Additionally, the fourth and fifth sides 267a-f, 269a-f are oriented such that they define an angle between <NUM>° and <NUM>°. First and second extenders 264a-f, 266a-f are attached to the fourth and fifth sides 267a-f, 269a-f. Each extender 264a-f, 266a-f includes a hole <NUM> extending therethrough. The extenders 264a-f, 266a-f and the main panels 250a-f of each petal 262a-f bend at a midpoint between the second and third sides 263a-f, 265a-f of each petal 262a-f such that, when viewed from the end (i.e., from the extenders towards the connection side) (similar to <FIG>), the petal 62a-f has a slight curvature of about <NUM>° to about <NUM>°.

The first petal 262a is folded by pivoting the first side 272a and the first petal 262a about the living hinge defined by the link <NUM> that is disposed between the first and second sides 272a, 272b in the direction of arrow "B". As such, the first petal 262a partially overlaps the second petal 262b. Subsequently, the first and second petals 262a, 262b are pivoted by pivoting the second side 272b about the living hinge defined by the link <NUM> that is disposed between the second side 272b and the third side 272c such that the second petal 262b partially overlaps the third petal 262c (<FIG>). Next, the first, second, and third petals 262a-c are pivoted by pivoting the third side 272c about the living hinge defined by the link <NUM> that is disposed between the third side 272c and the fourth side 272d such that the third petal 262c partially overlaps the fourth petal 262d. Subsequently, the first, second, third, and fourth petals 262a-d are pivoted by pivoting the fourth side 272d about the living hinge defined by the link <NUM> that is disposed between the fourth side 272d and the fifth side 272e such that the fourth petal 262d partially overlaps the fifth petal 262e. The first, second, third, fourth, and fifth petals 262a-e are pivoted by pivoting the fifth side 272e about the living hinge defined by the link <NUM> that is disposed between the fifth side 272e and the sixth side 272f such that the fifth petal 262e partially overlaps the sixth petal 262f and the sixth petal 262f partially overlaps the first petal 262a. The fully folded seal <NUM> is illustrated in <FIG>. All the folds occur in the direction identified by arrow "B".

After all the petals 262a-f are folded, a center orifice <NUM> is defined and is configured to engage an outer surface of a surgical instrument (not shown) inserted through the seal <NUM> such that the center orifice <NUM> surrounds the surgical instrument in a sealing manner to inhibit the passage of insufflation fluids and defines a fluid tight barrier. Further, once the petals 262a-f are folded over, the holes <NUM> of the petals 262a-f are aligned thereby allowing pins <NUM> of the retainer <NUM> to pass through the holes <NUM>. In this embodiment, the pins <NUM> are insertable through bores <NUM> of the guard assembly <NUM>, the holes <NUM> of the instrument seal, and the openings <NUM> of the second ring <NUM> of the retainer <NUM>. This arrangement aligns the relative positions of the guard assembly <NUM> and the instrument seal <NUM>. Although illustrated with pins <NUM> extending from the first ring <NUM> towards openings <NUM> in the second ring <NUM>, the retainer may have the pins located on the second ring and the openings on the first ring. Alternatively, the first and second rings may have an alternating arrangement of pins and openings that are complementary such that the pins of one of the rings align with openings of the other of the rings allowing the rings to be attached to one another and define the retainer.

As each petal 262a-f at least partially overlaps a first adjacent petal <NUM> and is at least partially overlapped by a second adjacent petal <NUM>, the petals 262a-f of the seal are interwoven. This interwoven arrangement of the petals 262a-f facilitates the seal <NUM> maintaining its shape during insertion and withdrawal of a surgical instrument through the center orifice <NUM>. For example, with additional reference to <FIG>, the seal <NUM> would replace the seal <NUM> and the centering mechanism <NUM>. <FIG> illustrates the placement of the instrument seal <NUM> in vale housing <NUM> of the cannula assembly <NUM>. During insertion of the surgical instrument through the valve housing <NUM> of the surgical access assembly <NUM>, a shaft of the surgical instrument passes through the central opening <NUM> of the first ring <NUM>, the central orifice <NUM> of the guard assembly <NUM>, the center orifice <NUM> of the instrument seal <NUM>, and the central opening <NUM> of the second ring <NUM>. As the shaft of the surgical instrument passes through the center orifice <NUM> of the seal <NUM> during insertion, the petals 262a-f of the seal <NUM> flex towards the second ring <NUM> and surround an outer surface of the shaft of the surgical instrument providing a fluid tight barrier between the petals 262a-f of the seal <NUM> and the shaft of the surgical instrument. During withdrawal of the surgical instrument, the petals 262a-f of the seal <NUM> flex towards a proximal portion of the valve housing <NUM> in response to proximal movement of the shaft of the surgical instrument. The petals 262a-f of the seal <NUM> resiliently return to their initial or rest configuration (<FIG>) once the shaft of the surgical instrument is removed from the center orifice <NUM> of the seal <NUM>. Due to the petals 262a-f being interwoven, they return to their initial configuration. In the event that the petals 262a-f have slightly different rates of movement, the interwoven arrangement of the petals 262a-f results in the slowest moving petal <NUM> acting as a governor and limiting the rate of movement of the remaining petals <NUM>. This tends to maintain contact between the petals 262a-f and the outer surface of the shaft of the surgical instrument thereby maintaining the fluid tight boundary of the seal <NUM> with respect to the surgical instrument during movement of the shaft relative to the seal <NUM>.

Referring now to <FIG>, the instrument seal <NUM> is positioned in the valve housing <NUM> and the fins 280a-f contact an inner wall <NUM> of the valve housing <NUM>. In an initial state, the normal biasing force exerted by the fins 280a-f act to center the instrument seal <NUM> in the valve housing <NUM> such that the center orifice <NUM> is aligned with the central longitudinal axis "X" of the cannula assembly <NUM> (<FIG>). When a surgical instrument is inserted through the valve housing <NUM> and the center orifice <NUM>, any radial movement of the surgical instrument relative to the longitudinal axis "X" moves the instrument seal <NUM> in the same radial direction. This results in the center orifice <NUM> being radially offset from the central longitudinal axis "X". In particular, when the instrument seal <NUM> is moved radially, the fins 280a-f in the direction of movement are compressed more while the fins 280a-f on the opposing side a relaxed more. Thus, when the force is removed, the compressed fins 280a-f will move towards their initial position and return the instrument seal <NUM> to its at rest position where the center orifice <NUM> is aligned with the central longitudinal axis "X". It is contemplated that all of the fins 280a-f will be slightly compressed when the instrument seal <NUM> is disposed within the valve housing <NUM>.

Each petal 262a-f is connected to a corresponding side 272a-f of the frame <NUM> along a first or connection side 261a-f. Each petal 262a-f also includes angled second and third sides 263a-f, 265a-f that extend from the corresponding connection side 261a-f in a divergent manner. Fourth and fifth sides 267a-f, 269a-f of each petal 262a-f interconnect the angled second and third sides 263a-f, 265a-f. The fourth and fifth sides 267a-f, 269a-f of the petals 262a-f have equal lengths and are angled towards the corresponding connection side 261a-f such that they meet at a point that would bisect the connection side 261a-f. The fourth and fifth sides are oriented such that they that they define an angle of <NUM>°. The fourth and fifth sides may define an angle between about <NUM>° and about <NUM>°. First and second extenders 262a-f, 264a-f are attached to the fourth and fifth sides 267a-f, 269a-f. The first and second extenders 262a-f, 264a-f have equal lengths and meet at a taper 273a-f that also is located at a point that would bisect the corresponding connection side 261a-f.

Claim 1:
A surgical access assembly (<NUM>) comprising:
a housing (<NUM>);
a tubular member (<NUM>) extending from the housing;
a valve assembly (<NUM>) disposed in the housing (<NUM>), the valve assembly including:
a guard assembly (<NUM>) having a central orifice (<NUM>), and
an instrument seal (<NUM>, <NUM>) having a central hole (<NUM>, <NUM>) aligned with the central orifice (<NUM>) of the guard assembly (<NUM>), the instrument seal including a frame (<NUM>, <NUM>) formed of a plurality of segments (172a-f, 272a-f), each segment having a top surface and a bottom surface and having a respective petal (162a-f, 262a-f) flexibly coupled to a side thereof by a living hinge, the instrument seal having an unfolded configuration defined by the petals (162a-f, 262a-f) extending away from a center of the frame (<NUM>, <NUM>) and a folded configuration defined by the petals folded towards the central hole (<NUM>, <NUM>) of the instrument seal wherein each petal at least partially overlaps an adjacent petal such that the petals interlock,
characterized in that each petal (162a-f, 262a-f) is attached to the corresponding segment (172a-f, 272a-f) of the frame (<NUM>, <NUM>) via the living hinge such that each petal and the corresponding living hinge define an acute angle with respect to either the top surface or the bottom surface of the segment (172a-f, 272a-f) of the frame (<NUM>, <NUM>).