Patent Description:
A trocar assembly generally includes a trocar and a seal assembly operatively coupled to or forming part of the trocar. The trocar includes a trocar housing and a cannula that extends distally from the trocar housing and provides the pathway into the patient's abdomen. The seal assembly includes one or more seals that help maintain insufflation of the penetrated body cavity and also seal about surgical tools extended through the trocar and into the patient's abdomen. In some applications, the seal assembly may comprise a seal cartridge at least partially received within the trocar housing.

Trocar seal assemblies commonly include a "duckbill" seal, which is normally closed until penetrated by the shaft of a surgical tool, at which point the duckbill seal receives and engages the outer circumference of the tool shaft as the surgical tool is introduced into the patient's abdomen. Because of its distally-protruding design, the duckbill seal typically generates smaller drag forces against the tool shaft while inserting the surgical tool as compared to the drag forces generated while extracting the surgical tool.

The variance between insertion and extraction drag forces can cause hysteresis, as a user (e.g., a surgeon) does not typically or consciously anticipate the added amount of force required to extract the surgical tool as compared to the force required to insert the surgical tool. In severe cases, this can cause inadvertent damage or injury to patient tissue. For robotic surgical applications, dissimilar insertion and extraction drag forces requires the robot to be programmed and calibrated separately for insertion and extraction movements to compensate for the different drag forces in each direction, thus further complicating the system.

In <CIT>, there is described a trocar sleeve assembly including a cannula connected to a housing assembly to define a working channel, wherein the housing assembly includes a housing that defines an opening in fluid communication with the working channel, a sleeve slidably received over the housing to define an annular region between the sleeve and the housing, a first sealing member forming a first seal between the sleeve and the housing, and a second sealing member forming a second seal between the sleeve and the housing.

In <CIT>, there is described a surgical trocar having a cannula assembly including a sleeve having a proximal end, a distal end and a passageway therethrough.

In <CIT>, there is described a cannula seal including a base portion that engages with a cannula; and a seal portion integrally formed with the base portion that slidably engages with an instrument shaft such that an insertion frictional force between the seal portion and the instrument shaft for insertion of the instrument shaft is symmetrical and substantially equal with a retraction frictional force.

In <CIT>, there is described a surgical instrument, a robotic surgical system, a cannula, a cannula seal, and a method for sensing of z-axis forces on a robotic surgical instrument.

In <CIT>, there is described a trocar to form a seal around a surgical instrument and a cannula having an axis extending between a proximal end and a distal end.

In <CIT>, there is described a gas-tight seal assembly for use during minimally invasive surgery.

The present invention provides an integral seal system as recited in claim <NUM>. Optional features are recited in the dependent claims.

The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure; the invention being as defined by the claims.

The present disclosure is related to trocar assemblies and, more particularly, to an integral seal system designed to equalize insertion and extraction drag forces generated against a surgical tool shaft.

The embodiments presented herein described an integral seal system that is designed to equalize surgical tool insertion and extraction forces. More specifically, the integral seal system may be included in a trocar assembly that includes a trocar having a trocar housing and a cannula that extends distally from the trocar housing. The integral seal system may be positioned within a central passageway extending axially through the trocar and may be engageable against a surgical tool shaft extended therethrough. The integral seal system includes an asymmetric seal and a duckbill seal arranged distal to the asymmetric seal, and the asymmetric seal defines a diaphragm that protrudes proximally and operates to complement insertion and extraction drag forces generated by the duckbill seal against the surgical tool shaft such that total insertion and extraction drag forces generated by the integral seal system are equalized.

<FIG> is an isometric view of an example trocar assembly <NUM> that may incorporate the principles of the present disclosure. The depicted trocar assembly <NUM> is just one example of a trocar assembly that can suitably incorporate the principles of the present disclosure. Those skilled in the art will readily appreciate that many alternative designs and configurations of the trocar assembly <NUM> may be employed or incorporated, without departing from the scope of this disclosure.

As illustrated, the trocar assembly <NUM> may include a trocar <NUM>, a seal cartridge <NUM> releasably coupled to the trocar <NUM>, and a trocar bushing <NUM> that may be releasably coupled to a proximal end of the seal cartridge <NUM>. The trocar <NUM> includes a trocar housing <NUM> and a cannula <NUM> that extends distally from the trocar housing <NUM>. The cannula <NUM> may comprise an integral extension of the trocar housing <NUM>. Alternatively, the trocar housing <NUM> and the cannula <NUM> may comprise two separate components that are mated to one another. The trocar <NUM> may be made of any rigid or semi-rigid material, such as a metal or a plastic.

The seal cartridge <NUM> may be at least partially received within the trocar housing <NUM> and include one or more actuatable latches <NUM> (one shown and one hidden) that releasably couple the seal cartridge <NUM> to the trocar housing <NUM>. The trocar bushing <NUM> may include a bushing housing <NUM> that provides one or more actuatable latches <NUM> (one shown and one hidden) that releasably couple the trocar bushing <NUM> to the seal cartridge <NUM>. However, the trocar bushing <NUM> may be omitted from the trocar assembly <NUM>, without departing from the scope of the disclosure.

The trocar assembly <NUM> may also include an insufflation valve <NUM> (e.g., a stopcock valve) operable to regulate the influx of an insufflation fluid (e.g. carbon dioxide) used to elevate the interior walls of an inner body cavity (e.g., the abdomen) of a patient. In the illustrated assembly, the insufflation valve <NUM> is coupled to the seal cartridge <NUM> or otherwise forms an integral part thereof. However, the insufflation valve <NUM> may alternatively be coupled to the trocar housing <NUM> or may form an integral part thereof.

<FIG> is a partial exploded view of the trocar assembly <NUM> of <FIG>. More particularly, the trocar bushing <NUM> is shown separated from the seal cartridge <NUM>. As illustrated, the trocar bushing <NUM> includes a reducer shaft <NUM> that extends distally from the bushing housing <NUM>. To couple the trocar bushing <NUM> to the seal cartridge <NUM>, the reducer shaft <NUM> may be extended into a central orifice <NUM> defined in the proximal end of the seal cartridge <NUM>. The trocar bushing <NUM> may then be advanced distally to extend the reducer shaft <NUM> through the seal cartridge <NUM> and the trocar housing <NUM>, and ultimately into the interior of the trocar cannula <NUM>. The trocar bushing <NUM> may be releasably coupled to the seal cartridge <NUM> by receiving the actuatable latches <NUM> of the bushing housing <NUM> into corresponding latch apertures <NUM> defined on the proximal end of the seal cartridge <NUM>.

The trocar bushing <NUM> and the corresponding reducer shaft <NUM> may operate to reduce the effective inner diameter of the trocar assembly <NUM>, which enables the trocar assembly <NUM> to accommodate and center reduced-diameter surgical tools. For example, the trocar bushing <NUM> may be sized to accommodate surgical tools that have an outer diameter of <NUM>. When larger-diameter surgical tools are used, such as surgical tools that have an outer diameter of <NUM> or <NUM>, the trocar bushing <NUM> may be omitted and such larger-diameter surgical tools may be introduced into the trocar assembly <NUM> via the central orifice <NUM>.

<FIG> is an enlarged cross-sectional side view of a portion of the assembled trocar assembly <NUM>. As illustrated, the seal cartridge <NUM> may include one or more seals, namely, a first or "proximal" seal <NUM> and a second or "distal" seal <NUM>. The first and second seals <NUM>, <NUM> facilitate selective sealing of the trocar assembly <NUM> during operation. In the illustrated assembly, the first and second seals <NUM>, <NUM> receive and engage the outer surface of the reducer shaft <NUM> as extended through the seal cartridge <NUM>. In operation, the first seal <NUM> may be configured to sealingly engage the outer surface of the reducer shaft <NUM>. While two seals <NUM>, <NUM> are depicted in <FIG>, the seal cartridge <NUM> may alternatively include more or less than two seals, without departing from the scope of the disclosure.

The first seal <NUM> may comprise an expandable iris seal configured to receive and expand radially to seal against the reducer shaft <NUM> extended through the seal cartridge <NUM>. Alternatively, when the trocar bushing <NUM> is omitted, the first seal <NUM> may seal about the outer surface of a surgical tool shaft (not shown). The second seal <NUM> may be configured to help maintain insufflation when not penetrated, but may also seal against the outer circumference of the reducer shaft <NUM> when the trocar bushing <NUM> is used. As illustrated, the second seal <NUM> comprises a duckbill seal, as generally known to those skilled in the art.

The seals <NUM>, <NUM> may be made of an elastic or pliable material. Suitable elastic or pliable materials include, but are not limited to, rubber (e.g., natural rubber, synthetic rubber, nitrile rubber, silicone rubber, a urethane rubber, a polyether rubber, chloroprene rubber, ethylene propylene diene monomer, styrenebutadiene rubber, etc.), silicone, ethylene vinyl acetate, nylon, vinyl, spandex, polyurethane, polyethylene, polypropylene, polyisoprene, or any combination thereof.

The trocar assembly <NUM> may further include a shaft seal referred to herein as an integral seal system <NUM> positioned within a central passageway <NUM> extending axially through the trocar assembly <NUM>. The central passageway <NUM> may comprise any elongate pathway that extends axially through the trocar assembly <NUM> to receive and guide the surgical tool shaft as it is inserted and extracted. In the illustrated assembly, for example, the central passageway <NUM> is defined by the trocar bushing <NUM> as extended through the seal cartridge <NUM> and the trocar <NUM>. More particularly, the central passageway <NUM> is at least partially defined by the bushing housing <NUM> and the interior of the reducer shaft <NUM>.

The integral seal system <NUM> may be positioned within the central passageway <NUM> and otherwise arranged to sealingly engage the outer surface of a surgical tool shaft extended through the central passageway <NUM>. More specifically, as a surgical tool shaft (not shown) is introduced into the central passageway <NUM>, the integral seal system <NUM> operates to seal about the outer circumferential surface thereof. The integral seal system <NUM> may be made of any of the elastic or pliable materials mentioned herein for the seals <NUM>, <NUM>. The illustrated integral seal system <NUM> is arranged at a proximal end <NUM> of the reducer shaft <NUM> and may be retained between and otherwise interpose the proximal end <NUM> of the reducer shaft <NUM> and a portion of the bushing housing <NUM>. Alternatively, however, the integral seal system <NUM> may be arranged at any location along the central passageway <NUM>, without departing from the scope of the disclosure.

Those skilled in the art will readily appreciate that the central passageway <NUM> may be defined by other component parts of the trocar assembly <NUM>, without departing from the scope of the disclosure. As described below, for example, the trocar bushing <NUM> may be omitted and the central passageway <NUM> is alternatively defined contiguously through the seal cartridge <NUM> and the trocar <NUM>. In such assemblies, the integral seal system <NUM> may be arranged within the seal cartridge <NUM>, for example, or another location within the central passageway <NUM>. Alternatively, it is contemplated that the seal cartridge <NUM> and the trocar bushing <NUM> may both be omitted from the trocar assembly <NUM>, and the central passageway <NUM> may alternatively be defined through the trocar housing <NUM> and the cannula <NUM>. In such assemblies, the integral seal system <NUM> may be arranged coupled to the trocar housing <NUM> or another location along the central passageway <NUM>.

<FIG> are isometric top and bottom views, respectively, of one example of the integral seal system <NUM>. Referring first to <FIG>, the integral seal system <NUM> may provide a generally circular body <NUM> that defines a central opening <NUM>. Alternatively, the body <NUM> may exhibit other cross-sectional shapes, such as polygonal or oval, without departing from the scope of the disclosure. An asymmetric seal <NUM> may be defined by the body <NUM> and extend radially into the central opening <NUM>. As illustrated, the asymmetric seal <NUM> comprises a diaphragm <NUM> and an annular flange <NUM> that extends between the body <NUM> and the diaphragm <NUM>. As discussed below, the diaphragm <NUM> may be configured to engage and seal against the outer circumference of an object (e.g., a surgical tool shaft) extended through the center opening <NUM> and otherwise penetrating the integral seal system <NUM>.

In <FIG>, a duckbill seal <NUM> (alternately referred to as a "check valve") may be provided on a bottom <NUM> of the body <NUM> and otherwise extend distally from the bottom <NUM>. The duckbill seal <NUM> defines one or more parting lines <NUM> (one shown) that separate opposing seal flaps <NUM>. In its relaxed, unpenetrated state, the seal flaps <NUM> remain closed (sealed) along the parting line(s) <NUM> and the duckbill seal <NUM> thereby helps to maintain insufflation. As an object (e.g., a surgical tool shaft) is extended through the center opening <NUM>, the duckbill seal <NUM> may open along the parting line(s) <NUM> as the seal flaps <NUM> separate to engage and seal against the outer circumference of the object.

While the duckbill seal <NUM> is depicted with a particular configuration and design, those skilled in the art will readily recognize that other configurations and designs may alternatively be employed, without departing from the scope of the disclosure. For example, the duckbill seal <NUM> may include two bisecting parting lines (e.g., "double slit") that define four or more seal flaps.

<FIG> is a cross-sectional view of the integral seal system <NUM> perpendicular to the parting line <NUM> of <FIG>. As illustrated, the asymmetric seal <NUM> extends radially into the central opening <NUM> and terminates with the diaphragm <NUM>, and the duckbill seal <NUM> extends distally from the bottom <NUM> of the body <NUM>. The integral seal system <NUM> may be molded as single structure that includes both the asymmetric and duckbill seals <NUM>, <NUM>. Alternatively, however, the integral seal system <NUM> may comprise a multi-component structure. In such assemblies, the duckbill seal <NUM>, for example, may be overmolded onto the body <NUM>. Alternatively, the duckbill seal <NUM> may be attached to the body <NUM> using for example, an adhesive, ultrasonic welding, one or more mechanical fasteners, an interference fit, a snap fit, or any combination thereof.

As an object, such as a surgical tool shaft, is extended through the center opening <NUM>, drag forces will be generated as the asymmetric and duckbill seals <NUM>, <NUM> independently engage the outer circumference of the tool shaft. Due to the distally-extending construction and design of the duckbill seal <NUM>, insertion and extraction drag forces generated by the duckbill seal <NUM> against the tool shaft will be dissimilar. More specifically, drag forces generated by the seal flaps <NUM> engaging the outer circumference of the tool shaft may be smaller (lower) as the tool shaft is inserted (i.e., advanced distally) as compared to drag forces generated as the tool shaft is extracted (i.e., retracted proximally).

Dissimilar insertion and extraction drag forces can result in hysteresis since a user (e.g., a surgeon) must actively adjust the insertion and extraction forces applied to the surgical tool during use. Consequently, the user has to mentally gauge the amount of force required to insert or extract a surgical tool, which can adversely affect controllability and potentially cause damage or injury to the patient. For robotic surgical applications, the robot is powered by one or more motors operable to push and pull on the surgical tool. Dissimilar insertion and extraction drag forces require the robot to be programmed and calibrated differently for the opposing movements such that an equal but opposite command input velocity for tool insertion and extraction results in equal and opposite physical performance of the tool.

The asymmetric seal <NUM> may be configured to compensate for the dissimilar insertion and extraction drag forces generated by the duckbill seal <NUM> and thereby provide the integral seal system <NUM> with a "total" drag force that is consistent (uniform) during tool insertion and extraction. To accomplish this, the asymmetric seal <NUM> may be tuned and otherwise optimized to generate larger drag forces during tool insertion, and smaller drag forces during tool extraction. When the drag forces generated by the asymmetric seal <NUM> are combined with the drag forces generated by the duckbill seal <NUM>, the net drag forces generated by the integral seal system <NUM> as a whole may be equal (or close to equal) in both directions for tool insertion and extraction. As a result, operation of the surgical tool by a user (e.g., a surgeon) may be more consistent and reliable, and for robotic surgical applications there may be no need to calibrate or program different speeds for tool insertion and extraction movement.

To enable the asymmetric seal <NUM> to generate larger tool insertion drag forces and smaller tool extraction drag forces, the diaphragm <NUM> may extend (protrude or project) proximally and otherwise away from the duckbill seal <NUM>. Said differently, in its relaxed state, the diaphragm <NUM> may be configured to project from the flange <NUM> proximally or in the proximal direction. As illustrated, the diaphragm <NUM> may exhibit a bulbous or spherical cross-section. Alternatively, however, the diaphragm <NUM> may exhibit other cross-sectional shapes such as, but not limited to, polygonal, pyramidal, conical, frustoconical, ovoid, or any combination thereof.

In the illustrated assembly, the diaphragm <NUM> has a spherical or circular cross-section and exhibits a diameter D. The magnitude of the diameter D and the cross-sectional circumferential connection location to the annular flange <NUM>, as well as the size and extent of the annular flange <NUM> (e.g., a thickness T) may be varied to tune the asymmetric seal <NUM> to generate insertion and extraction drag forces that when superimposed with the corresponding insertion and extraction drag forces of the duckbill seal <NUM>, the net total insertion and extraction drag for of the integral seal system <NUM> may be equal.

As used herein, the terms "equal" or "equalize" do not necessarily mean exactly equal or exactly equalized. As described herein, for instance, the asymmetric seal <NUM> may operate to offset or complement the drag forces generated by the duckbill seal <NUM>, such that the net drag forces generated by the integral seal system <NUM> as a whole may be "equal" or "equalized. " This does not mean that the net insertion and extraction drag forces are exactly equal or exactly equalized, although that certainly may be the case. Rather, equalizing the net insertion and extraction drag forces refers to bringing the total insertion drag force closer in magnitude to the total extraction drag force, or vice versa, through operation of the asymmetric seal <NUM>.

<FIG> are progressive cross-sectional side views of the integral seal system <NUM> during example operation. More specifically, <FIG> depict an example surgical tool shaft <NUM> in the process of being inserted (i.e., distally advanced) into the integral seal system <NUM>, and <FIG> depicts the shaft <NUM> being extracted (i.e., proximally retracted) from the integral seal system <NUM>. In <FIG>, the shaft <NUM> is advanced distally toward the integral seal system <NUM>, as indicated by the arrow A. Before the shaft <NUM> penetrates the integral seal system <NUM>, the diaphragm <NUM> projects proximally in its relaxed state. As mentioned above, this enables the asymmetric seal <NUM> to have larger tool insertion drag forces as compared to drag forces generated during tool extraction. Moreover, before the shaft <NUM> penetrates the integral seal system <NUM>, the duckbill seal <NUM> remains closed at the parting line(s) <NUM> and helps maintain insufflation.

In <FIG>, the shaft <NUM> has advanced distally A into the integral seal system <NUM> a short distance and the diaphragm <NUM> has engaged an outer surface <NUM> of the shaft <NUM>. The engagement between the diaphragm <NUM> and the outer surface <NUM> provides a fluid seal that prevents fluids (i.e., gases and liquids) from migrating past that location in either direction. Moreover, the friction generated by the diaphragm <NUM> against the shaft <NUM> causes the diaphragm <NUM> to flex distally, which generates an insertion drag force against the outer surface <NUM>. At this point, the duckbill seal <NUM> may also start to open at the parting line <NUM> as a result of a radial load assumed by the diaphragm <NUM>, which is partially transferred to the duckbill seal <NUM>.

In <FIG>, the shaft <NUM> has advanced distally A even further into the integral seal system <NUM> and now engages the inner walls of the duckbill seal <NUM> and, more particularly, the inner walls of the seal flaps <NUM>. The insertion drag force generated by the diaphragm <NUM> against the outer surface <NUM> of the shaft <NUM> may be constant as the shaft <NUM> continues its distal movement. Additional insertion drag forces are incurred as the shaft <NUM> advances through the duckbill seal <NUM> and the seal flaps <NUM> engage the outer surface <NUM> of the shaft <NUM>. However, since the seal flaps <NUM> are designed to protrude (extend) distally, the insertion drag forces generated by the duckbill seal <NUM> are smaller as compared to the extraction drag forces when extracting the shaft <NUM> proximally.

In <FIG>, the shaft <NUM> has advanced distally A to fully penetrate the integral seal system <NUM> and fully engage the inner walls of the seal flaps <NUM>. The insertion drag forces generated by the diaphragm <NUM> and the seal flaps <NUM> now combine to provide a total insertion drag force generated by the integral seal system <NUM> against the shaft <NUM>. The insertion drag forces generated by the diaphragm <NUM> and the seal flaps <NUM> against the outer surface <NUM> of the shaft <NUM> may be constant as the shaft <NUM> continues distal movement.

In <FIG>, the shaft <NUM> is depicted in the process of being extracted from the integral seal system <NUM> in the proximal direction, as indicated by the arrow B. As the shaft <NUM> reverses direction, the friction generated by the diaphragm <NUM> against the shaft <NUM> causes the diaphragm <NUM> to flex proximally, which generates an extraction drag force against the outer surface <NUM>. Since the diaphragm <NUM> naturally protrudes in the proximal direction B, the extraction drag forces generated by the asymmetric seal <NUM> may be smaller than its insertion drag forces. Additional extraction drag forces are generated by the duckbill seal <NUM> as the seal flaps <NUM> continue to engage the outer surface <NUM> of the shaft <NUM>. Since the seal flaps <NUM> naturally extend distally, the extraction drag forces generated by the duckbill seal <NUM> may be larger than its insertion drag forces.

The extraction drag forces generated by the diaphragm <NUM> and the seal flaps <NUM> combine to provide a total extraction drag force generated by the integral seal system <NUM> against the shaft <NUM>. Since the asymmetric seal <NUM> is designed to complement (offset) the insertion and drag forces of the duckbill seal <NUM>, the total insertion and extraction drag forces of the integral seal system <NUM> may be equalized and otherwise equal in both directions. Consequently, a user (e.g., a surgeon) or a robot may apply the same or equal amount of force on the shaft <NUM> to insert or extract the surgical tool through the integral seal system <NUM>.

<FIG> is an enlarged cross-sectional side view of another trocar assembly <NUM> that may incorporate the principles of the present disclosure. The trocar assembly <NUM> may be similar in some respects to the trocar assembly <NUM> of <FIG> and therefore may be best understood with reference thereto, where like numerals will represent like components not described again in detail. Similar to the trocar assembly <NUM> of <FIG>, the trocar assembly <NUM> may include the trocar <NUM> and the seal cartridge <NUM> at least partially received within the trocar housing <NUM>. Unlike the trocar assembly <NUM> of <FIG>, however, the trocar bushing <NUM> (<FIG>) is omitted from the trocar assembly <NUM>, and the first seal <NUM> (<FIG>) of the seal cartridge <NUM> in <FIG> has been replaced with the integral seal system <NUM>, as generally described above.

The integral seal system <NUM> is positioned within a central passageway <NUM> extending axially through the trocar assembly <NUM>. Similar to the central passageway <NUM> of <FIG>, the central passageway <NUM> comprises an elongate pathway that extends axially through the trocar assembly <NUM> and provides a conduit to guide and introduce surgical tools into an internal body cavity of a patient. In the illustrated system, the central passageway <NUM> is contiguously defined by the seal cartridge <NUM> and the trocar <NUM>. Surgical tools may be introduced into the trocar <NUM> and extended into the cannula <NUM> by extending through the central orifice <NUM> and successively penetrating the integral seal system <NUM> and the second seal <NUM>. The asymmetric seal <NUM> may be designed and optimized to complement (offset) the insertion and extraction drag forces generated by both the duckbill seal <NUM> and the second seal <NUM>. Consequently, the asymmetric seal <NUM> may be configured to equalize the net drag forces against the surgical tool shaft during insertion and extraction.

<FIG> is an enlarged cross-sectional side view of another trocar assembly <NUM> that may incorporate the principles of the present disclosure. The trocar assembly <NUM> may be similar in some respects to the trocar assembly <NUM> of <FIG> and therefore may be best understood with reference thereto, where like numerals will represent like components not described again in detail. Similar to the trocar assembly <NUM> of <FIG>, the trocar assembly <NUM> may include the trocar <NUM> and the seal cartridge <NUM> at least partially received within the trocar housing <NUM>.

Unlike the trocar assembly <NUM> of <FIG>, however, the seal cartridge <NUM> may include a shaft seal referred to herein as an integral seal system <NUM> that includes an asymmetric seal <NUM> axially separated from a duckbill seal <NUM>. The asymmetric and duckbill seals <NUM>, <NUM> may be similar in structure and function to the asymmetric and duckbill seals <NUM>, <NUM> of the integral seal system <NUM> of <FIG>, <FIG>, and <FIG>. The asymmetric and duckbill seals <NUM>, <NUM> of <FIG>, however, may comprise independent structures that are axially offset from each other and otherwise arranged at isolated positions within the seal cartridge <NUM>.

The integral seal system <NUM> is positioned within a central passageway <NUM> extending axially through the trocar assembly <NUM>. Similar to the central passageway <NUM> of <FIG>, the central passageway <NUM> comprises an elongate pathway that extends axially through the trocar assembly <NUM> and provides a conduit to guide and introduce surgical tools into an internal body cavity of a patient. In the illustrated system, the central passageway <NUM> is contiguously defined by the seal cartridge <NUM> and the trocar <NUM>. Surgical tools may be introduced into the trocar <NUM> and extended into the cannula <NUM> by extending through the central orifice <NUM> and penetrating the integral seal system <NUM> and, more particularly, successively penetrating the asymmetric and duckbill seals <NUM>, <NUM>. The integral seal system <NUM> operates similar to the integral seal system <NUM> of <FIG>, <FIG>, and <FIG> in that the asymmetric seal <NUM> may be designed and optimized to complement (offset) the insertion and extraction drag forces generated by the duckbill seal <NUM>. Consequently, the asymmetric seal <NUM> may be configured to equalize the net drag forces against the surgical tool shaft during insertion and extraction.

<FIG> is an enlarged cross-sectional side view of another trocar assembly <NUM> that may incorporate the principles of the present disclosure. The trocar assembly <NUM> may be similar in some respects to the trocar assembly <NUM> of <FIG> and therefore may be best understood with reference thereto, where like numerals will represent like components not described again in detail. Similar to the trocar assembly <NUM> of <FIG>, the trocar assembly <NUM> may include the trocar <NUM>. Unlike the trocar assembly <NUM> of <FIG>, however, the trocar busing <NUM> and the seal cartridge <NUM> are omitted from the trocar assembly <NUM>, and the integral seal system <NUM> generally described herein may be operatively coupled to the trocar housing <NUM>. The illustrated integral seal system <NUM> is mounted at least partially external to the trocar housing <NUM>. Alternatively, however, it is contemplated herein that the integral seal system <NUM> may be positioned entirely within the trocar housing <NUM>, such as through a snap fit engagement with the internal walls of the trocar housing <NUM>.

The integral seal system <NUM> is positioned within a central passageway <NUM> extending axially through the trocar assembly <NUM>. Similar to the central passageway <NUM> of <FIG>, the central passageway <NUM> comprises an elongate pathway that extends axially through the trocar assembly <NUM> and provides a conduit to guide and introduce surgical tools into an internal body cavity of a patient. In the illustrated system, the central passageway <NUM> is contiguously defined by the trocar housing <NUM> and the cannula <NUM>. Surgical tools may be introduced into the trocar <NUM> and extended into the cannula <NUM> by penetrating the integral seal system <NUM>. As generally described above, the asymmetric seal <NUM> may complement (offset) the insertion and extraction drag forces generated by the duckbill seal <NUM>, which equalizes the net drag forces against the surgical tool shaft during insertion and extraction.

Disclosed herein, but not forming part of the claimed invention, is:.

Each of A and B may have one or more of the following additional elements in any combination: Element <NUM>: further comprising a seal cartridge releasably coupled to the trocar, and a trocar bushing releasably coupled to the seal cartridge and including a reducer shaft extendable through the seal cartridge and into the cannula, wherein the central passageway is defined by the trocar bushing. Element <NUM>: wherein the integral seal system is arranged at a proximal end of the reducer shaft. Element <NUM>: further comprising a seal cartridge releasably coupled to the trocar, wherein the central passageway is contiguously defined by the seal cartridge and the trocar, and wherein the diaphragm complements insertion and extraction drag forces generated by the duckbill seal and an additional seal arranged within the seal cartridge such that the total insertion and extraction drag forces generated by the integral seal system and the additional seal are equalized. Element <NUM>: further comprising a seal cartridge releasably coupled to the trocar, wherein the central passageway is contiguously defined by the seal cartridge and the trocar, and wherein the asymmetric seal and the duckbill seal comprise independent structures axially offset from each other within the central passageway. Element <NUM>: wherein the integral seal system is mounted to the trocar housing. Element <NUM>: wherein the integral seal system comprises a body that defines a central opening and the asymmetric seal is defined by the body and extends radially into the central opening, and wherein the duckbill seal extends distally from a bottom of the body. Element <NUM>: wherein an annular flange extends between the body and the diaphragm. Element <NUM>: wherein the asymmetric seal generates larger drag forces during tool insertion and smaller drag forces during tool extraction, and wherein the duckbill seal generates smaller drag forces during tool insertion and larger drag forces during tool extraction. Element <NUM>: wherein the diaphragm exhibits a cross-sectional shape selected from the group consisting of bulbous, spherical, polygonal, pyramidal, conical, frustoconical, ovoid, and any combination or plurality thereof. Element <NUM>: wherein the diaphragm protrudes proximally relative to the duckbill seal.

Element <NUM>: wherein the trocar assembly further includes a seal cartridge releasably coupled to the trocar, and a trocar bushing releasably coupled to the seal cartridge and including a reducer shaft extendable through the seal cartridge and into the cannula, and wherein the central passageway is defined by the trocar bushing. Element <NUM>: wherein the trocar assembly further includes a seal cartridge releasably coupled to the trocar, and wherein the central passageway is contiguously defined by the seal cartridge and the trocar, the method further comprising generating a third insertion drag force as an additional seal arranged within the seal cartridge engages the surgical tool shaft, generating a third extraction drag force with the additional seal as the surgical tool is extracted, and complementing the second and third insertion drag forces with the first insertion drag force, and complementing the second and third extraction drag forces with the first extraction drag force such that the total insertion and extraction drag forces generated by the integral seal system and the additional seal are equalized. Element <NUM>: wherein the trocar assembly further includes a seal cartridge releasably coupled to the trocar and the central passageway is contiguously defined by the seal cartridge and the trocar, and wherein the asymmetric seal and the duckbill seal comprise independent structures axially offset from each other within the central passageway. Element <NUM>: wherein the integral seal system is mounted to the trocar housing.

Element <NUM>: wherein the asymmetric seal is engageable with the surgical tool shaft and generates larger drag forces during tool insertion and smaller drag forces during tool extraction, and wherein the duckbill seal generates smaller drag forces during tool insertion and larger drag forces during tool extraction. Element <NUM>: wherein the diaphragm exhibits a cross-sectional shape selected from the group consisting of bulbous, spherical, polygonal, pyramidal, conical, frustoconical, ovoid, and any combination or plurality thereof. Element <NUM>: wherein the body is made from an elastic or pliable material selected from the group consisting of rubber, silicone, ethylene vinyl acetate, nylon, vinyl, spandex, polyurethane, polyethylene, polypropylene, polyisoprene, and any combination thereof.

By way of non-limiting example, exemplary combinations applicable to A and B include: Element <NUM> with Element <NUM>; and Element <NUM> with Element <NUM>.

Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular assemblies and systems disclosed above are illustrative only. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative assemblies and systems disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be mentioned by reference, the definitions that are consistent with this specification should be adopted.

Claim 1:
An integral seal system (<NUM>; <NUM>) for a trocar assembly, comprising:
a body (<NUM>) that defines a central opening (<NUM>);
a duckbill seal (<NUM>; <NUM>) defining one or more parting lines (<NUM>) that separate opposing seal flaps (<NUM>), the seal flaps configured to naturally extend distally; and
an asymmetric seal (<NUM>; <NUM>) defined by the body (<NUM>) and extending radially into the central opening (<NUM>), the asymmetric seal (<NUM>; <NUM>) including a diaphragm (<NUM>) and an annular flange (<NUM>) that extends between the body (<NUM>) and the diaphragm (<NUM>), the diaphragm (<NUM>) configured to naturally protrude in the proximal direction,
wherein the diaphragm (<NUM>) of the asymmetric seal (<NUM>; <NUM>) is engageable with a surgical tool shaft (<NUM>) extended therethrough, and the asymmetric seal (<NUM>; <NUM>) is configured to generate larger drag forces against the surgical tool shaft during tool insertion than the drag forces generated against the surgical tool shaft during tool extraction, and in that the duckbill seal (<NUM>; <NUM>) is configured to generate smaller drag forces against the surgical tool shaft extended therethrough during tool insertion than the drag forces generated against the tool shaft during tool extraction, characterized in that:
the diaphragm (<NUM>) complements insertion and extraction drag forces generated by the duckbill seal (<NUM>; <NUM>) against the surgical tool shaft extended therethrough such that total insertion and extraction drag forces generated by the integral seal system are equalized.