Patent Description:
A trocar assembly generally includes a cannula, an obturator, and a housing. In order to access the body cavity, the cannula is directed through the skin and the obturator is inserted through an interior lumen defined by the cannula to provide penetration access to the body cavity. The cannula is then inserted through the perforation made by the obturator and the obturator is withdrawn, leaving the interior lumen of the cannula as a path to access the body cavity from outside the body. The trocar housing is attached to the proximal end of the cannula and defines a working chamber with an open distal end in communication with the interior lumen of the cannula. Just as the interior lumen can receive the obturator, it can also receive other elongated surgical instruments that are axially extended into and withdrawn from the cannula through the proximal end portion of the working chamber.

In robotic surgery incorporating trocar assemblies, surgical instruments having two or more different diameters can be used. The diameter of the trocar assembly is typically determined based on the diameter of the surgical instrument to be used. For example, a <NUM> trocar assembly will be used to enable a <NUM> surgical instrument (e.g., a surgical stapler) to be used. For some procedures, however, an <NUM> surgical instrument may be required to pass through the <NUM> trocar assembly.

A seal assembly or sealing device is commonly incorporated in the trocar assembly to help prevent fluid or gas from escaping during surgical procedures. Such prevention is needed, especially during certain minimally invasive surgical procedures in which an insufflation gas is used to expand the body cavity. The seal assembly operates to seal against the outer surface of inserted instruments and thus prevents fluids and insufflation gas from escaping and/or entering the body cavity through the cannula.

Some trocar seal assemblies include removable seal cartridges designed to accommodate surgical instruments of a particular outer diameter. When a surgical instrument of a different diameter is required, however, the seal cartridge is removed from the trocar housing and replaced with a different seal cartridge capable of accommodating the different diameter. While swapping out a seal cartridge for a properly sized seal cartridge, the insufflation in the body cavity needs to be maintained.

This presents a challenge in robotic surgery since surgical robots "drive" or locate the surgical instrument by rotating the trocar assembly around intra-abdominally. When a surgical instrument of a smaller diameter is used in a larger diameter trocar assembly (e.g., an <NUM> surgical instrument used in a <NUM> trocar assembly) there is "lost motion" or hysteresis to the movement. The initial movement input to the robot by the surgeon will not move the surgical instrument, but will instead first remove the clearance between the instrument and the trocar assembly, and will subsequently move the surgical instrument. This lost motion is unacceptable to the surgeon, who expects fine control and precision from the surgical robot.

The clearance between the trocar assembly and the smaller diameter surgical instrument can also result in the surgical instrument vibrating without hitting the inner walls of the trocar assembly. If an <NUM> surgical instrument is used in the same size <NUM> trocar assembly, this vibration is dampened by the instrument hitting the inner walls of the trocar assembly, but in the case of an <NUM> surgical instrument being used in a <NUM> trocar assembly, this vibration can occur undampened.

In <CIT>, there is described a surgical cannula including a first valve seal for preventing insufflation gas from escaping from a patient's abdomen when an instrument is inserted or removed through the cannula. In <CIT>, there is described a surgical instrument having an hourglass instrument seal operably coupled to the interior of the valve seal assembly.

In <CIT>, there are described methods and devices for accessing a body cavity.

<CIT>, there is described a trocar sleeve with a housing at the proximal end, a shaft projecting from said housing towards the distal end. <CIT>, there are described methods and devices for accessing a body cavity.

<CIT>, there is described a valve assembly for sealed reception of an elongated object including a valve body having at least one opening configured and dimensioned to permit entry of an elongated object and defining a central longitudinal axis.

The invention is defined by independent claim <NUM> with further embodiments disclosed 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 present disclosure is related to trocar assemblies and, more particularly, to seal assemblies that can be used in robotic trocar assemblies.

The embodiments described herein provide a trocar assembly with an integral seal that helps maintain insufflation pressure when removing and replacing a seal cartridge. Other embodiments described herein provide seal cartridges utilizable in a trocar assembly that include a telescoping bushing and/or sleeve that may operate to reduce the inner diameter of the trocar cannula lumen and thus help eliminate or minimize unintended movement and vibration of smaller surgical tools.

<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 trocar assembly that can suitably incorporate the principles of the present disclosure. Indeed, many alternative designs and configurations of the trocar assembly <NUM> may be employed, without departing from the scope of this disclosure.

As illustrated, the trocar assembly <NUM> includes a trocar housing <NUM> and a cannula <NUM>, and the cannula <NUM> has a proximal end 106a and a distal end 106b. The cannula <NUM> is coupled to the trocar housing <NUM> at the proximal end 106a and extends distally therefrom. In some embodiments, the cannula <NUM> may comprise an integral extension of the trocar housing <NUM>. In other embodiments, however, the trocar housing <NUM> and the cannula <NUM> may comprise two separate components that may be mated to one another. The trocar housing <NUM> and cannula <NUM> may be made of any rigid or semi-rigid material, such as a metal or a plastic.

The trocar assembly <NUM> may also include an insufflation valve <NUM> (e.g., a stopcock valve) coupled to the trocar housing <NUM> or forming an integral part thereof. The insufflation valve <NUM> is operable to introduce an insufflation fluid (e.g. carbon dioxide) through the trocar housing <NUM> and the cannula <NUM> and subsequently into an inner cavity (e.g., the abdomen) of a patient to elevate the interior walls of the inner cavity thereby creating more work room. While not shown, the trocar assembly <NUM> may also include an obturator extendable through the trocar assembly along a centerline A of the trocar assembly <NUM>. When used, the obturator extends through the cannula <NUM> and out the distal end 106b to penetrate a patient's skin and thereby facilitate access to the abdominal cavity.

<FIG> is an exploded view of the trocar assembly <NUM> of <FIG>. The trocar housing <NUM> provides and otherwise defines a working chamber <NUM> that communicates with a lumen defined within the cannula <NUM>. The lumen is open-ended and extends between the proximal and distal ends 106a,b of the cannula <NUM>.

The working chamber <NUM> is also open-ended and configured to at least partially receive a seal cartridge <NUM> that includes a first or "proximal" seal assembly 204a and a second or "distal" seal assembly 204b. The first and second seal assemblies 204a,b allow selective sealing of the working chamber <NUM> during operation. In at least one embodiment, as illustrated, the second seal assembly 204b may comprise a duckbill seal. While two seal assemblies 204a,b are depicted in <FIG>, the seal cartridge <NUM> may alternatively include more or less than two seal assemblies, without departing from the scope of the disclosure.

The seal assemblies 204a,b may be made of an elastic or pliable material, and 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, styrene-butadiene rubber, etc.), silicone, ethylene vinyl acetate, nylon, vinyl, spandex, polyurethane, polyethylene, polypropylene, polyisoprene, or any combination thereof. Example seal cartridges are described in <CIT>.

The seal cartridge <NUM> may be assembled in a variety of ways. In the illustrated embodiment, for example, a crown ring <NUM> and a gasket ring <NUM> may be snap-fit together, and a gasket retainer ring <NUM> may be configured to secure an attachment between the gasket ring <NUM> and the trocar housing <NUM>. A housing retainer <NUM> may then be extended about the exterior of the trocar housing <NUM> to secure the internal components to the trocar housing <NUM>. These components may be made of any rigid or semi-rigid material, such as a metal or a plastic.

<FIG> is a cross-sectional side view of the trocar assembly <NUM>. As illustrated, the cannula <NUM> defines and otherwise provides a lumen <NUM> that extends between the proximal and distal ends 106a,b and communicates with the working chamber <NUM> provided by the trocar housing <NUM>. The lumen <NUM> exhibits an inner diameter <NUM> configured to receive surgical tools having an outer diameter equal to (i.e., slightly less than equal) or less than the inner diameter <NUM>.

According to embodiments of the present disclosure, an additional or tertiary seal <NUM> may be incorporated into the trocar assembly <NUM> at or near a distal end or region <NUM> of the working chamber <NUM>. The tertiary seal <NUM> may alternately be referred to as a "distal seal," as the first and second seal assemblies 204a,b may alternately be referred to as a "proximal seal" and a medial seal," respectively. The tertiary seal <NUM> may prove advantageous in maintaining insufflation pressure when a surgical tool and/or seal cartridge such as seal cartridge <NUM> is removed from the trocar assembly <NUM> and replaced with a different tool and/or seal cartridge. In the illustrated embodiment, the tertiary seal <NUM> is disposed within the distal region <NUM> of the working chamber <NUM> and distally located from the second seal assembly 204b. In other embodiments, however, the tertiary seal <NUM> may be arranged in other locations within the working chamber <NUM>, without departing from the scope of the disclosure.

In one or more embodiments, the tertiary seal <NUM> is coupled to (integral with) the trocar housing <NUM> so that it remains in place within the working chamber <NUM> to maintain insufflation pressure. In at least one embodiment, the tertiary seal <NUM> is mounted within an annular ring or groove <NUM> formed in the inner surface of the working chamber <NUM> as illustrated in <FIG>. In other embodiments, the tertiary seal <NUM> is secured within the working chamber via an attachment means selected from the group consisting of one or more mechanical fasteners, a threaded engagement, welding, ultrasonic welding, brazing, an adhesive, an interference fit, a shrink fit, a mechanical attachment, and any combination thereof.

The tertiary seal <NUM> may comprise a variety of different types and configurations of seals capable of providing a sealed interface at the distal region <NUM> of the working chamber <NUM>. In at least one embodiment, the tertiary seal <NUM> may comprise a pass-through seal, such as a duckbill seal. Additionally, the tertiary seal <NUM> may be made of a pliable or elastic material including those mentioned herein with respect to the seal assemblies 204a,b of <FIG>.

As mentioned above, the lumen <NUM> exhibits an inner diameter <NUM> configured to receive surgical tools having an outer diameter less than or equal to the inner diameter <NUM>. In at least one embodiment, the inner diameter <NUM> may be sized to receive a <NUM> surgical tool. In such embodiments, the trocar assembly <NUM> may be referred to and otherwise characterized as a "<NUM> trocar," which is commonly used in robotic surgery to accommodate various <NUM> surgical tools, such as surgical staplers. In other embodiments, however, the inner diameter <NUM> may be differently sized (e.g., <NUM>, <NUM>, etc.). As a surgical tool is extended into the trocar assembly <NUM>, the first and second seal assemblies 204a,b and the tertiary seal <NUM> are configured to deform and provide a sealed interface against the outer surface of the surgical tool.

Where a surgical tool exhibits an outer diameter that is approximately equal to the inner diameter <NUM>, the surgical tool will be generally centered within the cannula <NUM> along the centerline A at all times, which tends to mitigate unwanted occurrences of deflection, oscillation, and vibration of the surgical tool. Accordingly, where a <NUM> surgical tool is inserted through a <NUM> trocar, the outer surface of the surgical tool will contact or be in close contact with the inner surface of the lumen <NUM> such that very little clearance remains between the surgical tool and the inner wall of the lumen <NUM>. As a result, the surgical tool may be generally centered within the lumen <NUM>, which mitigates deflection, oscillation, and vibration.

At times, however, surgical tools exhibiting outer diameters that are smaller than the inner diameter <NUM> (i.e., a smaller surgical tool) may need to be introduced into the trocar assembly <NUM>. In some applications, for example, the outer diameter of a smaller surgical tool may be approximately <NUM> (i.e., an "<NUM> surgical tool") or approximately <NUM> (i.e., a "<NUM> surgical tool"). As the smaller surgical tool is extended into the trocar assembly <NUM>, the first and second seal assemblies 204a,b and tertiary seal <NUM> are configured to deform and provide a sealed interface against the outer surface of such smaller surgical tool. The seal assemblies 204a,b and the tertiary seal <NUM> each helps maintain insufflation during various operations undertaken and while pulling the smaller surgical tool out of the cannula <NUM>.

However, since the outer diameter of the smaller surgical tool is smaller than the inner diameter <NUM> of the lumen <NUM>, the smaller surgical tool will rarely (if ever) be centered within the cannula <NUM> along the centerline A during operation. Rather, the smaller surgical tool will continuously be prone to deflection, oscillation in place, spring back oscillation, and vibration as it is manipulated in various directions during operation.

According to embodiments of the present invention, a sleeve or bushing is incorporated into the trocar assembly <NUM> and extends distally from the seal cartridge <NUM> at or near a distal end thereof into the lumen <NUM>. In such embodiments, the sleeve or bushing may operate as a reducer that accommodates smaller-diameter surgical tools and eliminates or significantly minimizes unintended movement and vibration of smaller surgical tools when fed through a lumen <NUM> having a larger inner diameter <NUM>.

<FIG> is a cross-sectional side view of a seal cartridge <NUM> in accordance with the claimed invention that may be utilized with the trocar assembly <NUM> of <FIG>. As illustrated, the seal cartridge <NUM> is at least partially arrangeable within the working chamber <NUM>.

The seal cartridge <NUM> may be similar to the seal cartridge <NUM> depicted in <FIG> in that the seal cartridge <NUM> may include a first or "proximal" seal assembly 404a and a second or "distal" seal assembly 404b. While two seal assemblies 404a,b are depicted in <FIG>, the seal cartridge <NUM> may alternatively include more or less than two seal assemblies to allow selective sealing of the working chamber <NUM> during operation, without departing from the scope of the disclosure.

In addition, the first and second seal assemblies 404a,b may be assembled and secured within seal cartridge <NUM> in a similar manner as utilized with respect to the seal cartridge <NUM> of <FIG>. Moreover, the first and second seal assemblies 404a,b may be made of a pliable or elastic material including those mentioned herein with respect to the seal assemblies 204a,b of <FIG>. In some embodiments, seal cartridge <NUM> may further comprise an auxiliary seal or gasket 404c, such as an O-ring or the like, that ensures a sealed interface between the periphery of the seal cartridge <NUM> and the inner wall of the working chamber <NUM>. The auxiliary seal 404c may also be made of a pliable or elastic material including those mentioned herein with respect to the seal assemblies 204a,b of <FIG>.

The seal cartridge <NUM> includes a sleeve or bushing <NUM>. In the illustrated embodiment, the bushing <NUM> is mounted or secured to a distal end 402b of the seal cartridge <NUM>, and the bushing <NUM> distally extends therefrom into and through the lumen <NUM> of the cannula <NUM>. In some embodiments, the bushing <NUM> extends through the entire length of the lumen <NUM> along centerline A, whereas in other embodiments the bushing <NUM> may terminate before the end of the lumen <NUM>.

Various attachment means may be utilized to mount or secure the bushing <NUM> to the seal cartridge <NUM>, including the use of one or more mechanical fasteners, a threaded engagement, welding, ultrasonic welding, brazing, an adhesive, an interference fit, a shrink fit, a mechanical attachment, and any combination thereof.

The bushing <NUM> includes a proximal portion 406a and a distal portion 406b that extends distally from the proximal portion 406a. In the illustrated embodiment, the proximal portion 406a is configured to be arranged within the distal region <NUM> of working chamber <NUM> when the seal cartridge <NUM> is installed and, in some embodiments, the proximal portion 406a is further configured to receive a seal assembly such as the second seal assembly 404b. For example, the proximal portion 406a may comprise a frustoconical portion or surface that connects to the distal portion 406b, and the frustoconical portion may be adapted to receive the second seal assembly 404b. Also in the illustrated embodiment, the distal portion 406b is configured to be received within the lumen <NUM> of the cannula <NUM>. Therefore, it will be appreciated that the proximal portion 406a may operate as a "reducer" that effectively reduces the inner diameter <NUM> of the lumen <NUM> to a reduced inner diameter <NUM> of the distal portion 406b.

The reduced inner diameter <NUM> may be sized to match the outer diameter of a smaller surgical tool inserted there-through (not illustrated) so that the smaller surgical tool will not oscillate or vibrate when utilized in conjunction with the trocar assembly <NUM>. For example, the inner diameter <NUM> may be approximately <NUM> or <NUM> in diameter to receive <NUM> surgical tools or <NUM> surgical tools, respectively. However, in other embodiments the reduced inner diameter <NUM> may still be larger than the outer diameter of the smaller surgical tool. In such embodiments, the smaller surgical tool will experience less unintended movement and/or vibration due to the reduced inner diameter <NUM> of the bushing <NUM> than would be experienced in applications without bushing <NUM>.

With reference to <FIG> and <FIG>, during operation, an internal body cavity (e.g., a patient's abdomen) will be pressurized or insufflated using the trocar assembly <NUM> to provide access for an operator or a surgeon. Once the cavity has been insufflated, the operator or surgeon may insert the seal cartridge <NUM> into the trocar assembly <NUM> to utilize a large surgical tool such as a <NUM> surgical tool. Situations may arise, however, where the operator or surgeon needs to utilize a smaller surgical tool such as an <NUM> or <NUM> surgical tool. In such situations, the operator or surgeon may remove the <NUM> surgical tool from the trocar assembly <NUM>, and may then remove the first seal cartridge <NUM> from the trocar assembly <NUM> in preparation for installing the second seal cartridge <NUM>, which includes the smaller diameter bushing <NUM>.

While removing the first seal cartridge <NUM> and installing the second seal cartridge <NUM>, insufflation pressure is maintained due to the presence of the tertiary seal <NUM> positioned within the distal region <NUM> of working chamber <NUM>. Installing the second seal cartridge <NUM> within the working chamber <NUM> includes inserting or penetrating the tertiary seal <NUM> with the distal portion 406b of the bushing <NUM> and introducing the distal portion 406b into the lumen <NUM>. Once the operator or surgeon has installed the seal cartridge <NUM>, the smaller surgical tool may then be extended into the trocar assembly <NUM> and through the reduced inner diameter <NUM> of the bushing <NUM>.

When no longer required, the smaller surgical tool may be removed from the trocar assembly <NUM> and the second seal cartridge <NUM> may then be removed from the working chamber <NUM>. During this process, insufflation pressure is still maintained, even with the bushing <NUM> still penetrating the tertiary seal <NUM> during removal, due to the presence of the second seal assembly 404b that is not penetrated by the smaller surgical tool and thus fully engaged or closed to maintain insufflation pressure.

<FIG> are cross-sectional side views of another example trocar assembly <NUM>, according to one or more additional embodiments of the present disclosure. The trocar assembly <NUM> may be similar in some respects to the trocar assembly <NUM> of <FIG>, where like numerals refer to similar components that may not be described in detail again. Similar to the trocar assembly <NUM> of <FIG>, the trocar assembly <NUM> includes the cannula <NUM> extending distally from the housing <NUM> and defining the lumen <NUM>. The trocar assembly <NUM> also includes the proximal and distal seal assemblies 204a,b of the seal cartridge <NUM>.

Unlike the trocar assembly <NUM> of <FIG>, however, the trocar assembly <NUM> further includes a telescoping bushing assembly <NUM>. As illustrated, the telescoping bushing assembly <NUM> is at least partially arrangeable within the working chamber <NUM>, and includes a ring <NUM>, a sleeve <NUM> that extends distally from the ring <NUM>, and a bushing <NUM> that is configured to translate or "telescope" within and relative to the sleeve <NUM>. Various attachment means may be utilized to mount or secure the sleeve <NUM> to the ring <NUM>, including the use of one or more mechanical fasteners, a threaded engagement, welding, ultrasonic welding, brazing, an adhesive, an interference fit, a shrink fit, a mechanical attachment, and any combination thereof. Moreover, the ring <NUM>, the sleeve <NUM>, and the bushing <NUM> may be made from any rigid or semi-rigid material like plastic or metal.

In the illustrated embodiment, the ring <NUM> is annular with an opening <NUM> configured to receive a surgical tool and is disposed on a proximal end <NUM> of the trocar assembly <NUM> and seal cartridge <NUM>. In some embodiments, the ring <NUM> may be secured to the proximal end <NUM> of the trocar assembly <NUM>. For example, suitable locking mechanisms may include, without limitation, a threaded engagement, one or more clips, one or more latches, a friction locking assembly, and any combination thereof. In other embodiments, however, the ring <NUM> may simply rest on the proximal end <NUM> of the trocar assembly <NUM>, without departing from the scope of the disclosure.

The sleeve <NUM> extends distally from the ring <NUM> and defines a channel or pathway 512a through which a surgical tool may be inserted. The bushing <NUM> also defines a channel or pathway 512b that communicates with the pathway 512a and through which a surgical tool may be inserted. The pathway 512b of the bushing <NUM> defines a diameter <NUM> that will be approximately equal to the diameter of the surgical tool inserted therethrough, though in some embodiments surgical tools having shafts smaller than the diameter <NUM> may be utilized therein. In these configuration, the smaller surgical tool will be generally centered within the cannula <NUM> along the centerline A at all times, which tends to mitigate unwanted occurrences of deflection, oscillation, and vibration of the surgical tool.

The bushing <NUM> also defines an outer diameter that is approximately equal to the inner diameter <NUM> of lumen <NUM>. In some embodiments, however, the bushing <NUM> defines an outer diameter that is less than the inner diameter <NUM> of lumen <NUM>. In such embodiments, the bushing <NUM> includes one or more flanges <NUM> (one shown) that radially extend from the periphery of the bushing <NUM> to abut or contact the inner wall of the lumen <NUM>, and thereby centering the bushing <NUM> within the lumen <NUM>. In one embodiment, the flange <NUM> may be an annular flange extending around the perimeter of the distal end of the bushing <NUM> and has an outer diameter approximately equal to the inner diameter <NUM> of the lumen <NUM>.

The telescoping bushing assembly <NUM> is movable between a retracted configuration, as shown in <FIG>, and an extended configuration, as shown in <FIG>. In the extended configuration, the sleeve <NUM> extends through the first seal assembly 204a and at least partially into the second seal assembly 204b. Moreover, in the extended configuration, the bushing <NUM> translates or "telescopes" out of the sleeve and thereby penetrates the second seal assembly 204b. When in the extended configuration, the bushing <NUM> extends through the second seal assembly 204b and into the lumen <NUM> such that the lumen <NUM> fluidly communicates with the ambient environment via the passageways 512a,b. In the retracted configuration, the bushing <NUM> is received into the pathway 512a of the sleeve <NUM> and does not penetrate the second seal assembly 204b. Insufflation pressure will be maintained when the telescoping bushing assembly <NUM> is in the retracted configuration.

In the illustrated embodiment, the telescoping bushing assembly <NUM> also includes a seal <NUM>, such as a diaphragm seal, annularly disposed within the passageway 512a at a proximal end thereof. The seal <NUM> is configured to sealingly engage the outer diameter of a surgical tool inserted therethrough, and may be made of a pliable or elastic material including those mentioned herein with respect to the seal assemblies 204a,b of <FIG>.

The telescoping bushing assembly <NUM> may also include one or more telescope seals 516a,b, such as annular elastomers, gaskets, or O-rings. The first telescope seal 516a is set within the passageway 512a of the sleeve <NUM> at a distal end thereof. The second telescope seal 516b is set within the passageway 512b of the bushing <NUM> at a distal end thereof. Either or both of the first and second telescope seals 516a,b may be made of a pliable or elastic material including those mentioned herein with respect to the seal assemblies 204a,b of <FIG>.

In the illustrated embodiment, the first telescope seal 516a abuts an outer periphery of the bushing <NUM> so as to "grip" and/or provide friction that resists axial translation of the bushing <NUM> along centerline A. The second telescope seal 516b may be configured to sealingly engage the outer surface of a surgical tool inserted through the passageway 512b. As discussed below, the second telescope seal 516b may also be configured to "grip" and otherwise provide a frictional engagement against the outer surface of the surgical tool as it is inserted therethrough, thereby distally extending or "carrying" the telescoping bushing <NUM> along centerline A.

<FIG> depict an example operation of the trocar assembly <NUM> of <FIG>, according to one or more embodiments. As illustrated, the telescoping bushing assembly <NUM> is shown transitioning from the retracted configuration, as depicted in <FIG>, to an intermediate configuration, as shown in <FIG>, and to the extended configuration, as shown in <FIG>. As also illustrated, a surgical tool <NUM> is shown being extended into the trocar assembly <NUM>. The surgical tool <NUM> includes a shaft <NUM> that penetrates the seal assemblies 204a,b and causes the telescoping bushing assembly <NUM> to transition between the retracted and extended configurations.

More specifically, <FIG> illustrate operation of the the telescoping bushing assembly <NUM> when utilized with the surgical tool <NUM>. As the shaft <NUM> enters the opening <NUM> of the ring <NUM>, it passes through the seal <NUM> and the pathway 512a of the sleeve <NUM> and into the pathway 512b of the telescoping bushing <NUM>. As the shaft <NUM> is driven through the pathway 512b of the telescoping bushing <NUM>, it encounters the second telescope seal 516b that "grips" the outer surface of the shaft <NUM> such that the surgical tool <NUM> carries or extends the telescoping bushing <NUM> along centerline A, through second seal assembly 204b, and ultimately into its extended position.

Upon retraction of the surgical tool <NUM>, the friction between the second telescope seal 516b and the shaft <NUM> of the surgical tool <NUM> retracts the telescoping bushing <NUM> in a proximal direction along centerline A past the second seal assembly 204b. In the illustrated embodiment, the shaft <NUM> of the surgical tool <NUM> will not be fully retracted from the passageway 512b of the bushing <NUM> until the bushing <NUM> is in its extreme distal orientation (<FIG>) such that seal assembly 204b is engaged or closed (i.e., with no portion of the surgical tool <NUM> extending there-through) to maintain insufflation pressure.

Each of embodiments A and C may have one or more of the following additional elements in any combination: Element <NUM>: wherein the tertiary seal is made of an elastic material selected from the group consisting of rubber, silicone, ethylene vinyl acetate, nylon, vinyl, spandex, polyurethane, polyethylene, polypropylene, polyisoprene, and any combination thereof. Element <NUM>: wherein the bushing is attached to the distal end of the seal cartridge via an attachment means selected from the group consisting of one or more mechanical fasteners, a threaded engagement, welding, ultrasonic welding, brazing, an adhesive, an interference fit, a shrink fit, a mechanical attachment, and any combination thereof. Element <NUM>: wherein the tertiary seal is disposed within a groove formed into a surface of the working chamber. Element <NUM>: wherein the groove is located at a distal region of the working chamber. Element <NUM>: wherein the tertiary seal is a duckbill seal. Element <NUM>: wherein the bushing extends through the lumen and terminates at a distal end of the cannula. Element <NUM>: wherein the bushing comprises a proximal portion that is configured to receive the distal seal assembly. Element <NUM>: wherein the proximal portion comprises a frustoconical portion. Element <NUM>: wherein the bushing comprises a proximal portion having a first diameter and a distal portion having a second diameter that is less than the first diameter. Element <NUM>: wherein the bushing comprises a distal portion having an inner diameter that is less than a diameter of the lumen. Element <NUM>: wherein insufflation pressure is maintained during removal of the seal cartridge from the working chamber with the tertiary seal.

Element <NUM>: wherein the tertiary seal is disposed within a groove formed into a surface of the working chamber. Element <NUM>: wherein the tertiary seal is a duckbill seal. Element <NUM>: wherein the second seal cartridge includes one or both of a proximal seal assembly and a distal seal assembly arranged distally from the proximal seal assembly.

Element <NUM>: wherein the tertiary seal is disposed within a groove formed into a surface of a distal region the working chamber. Element <NUM>: wherein the tertiary seal is a duckbill seal. Element <NUM>: wherein the seal cartridge further comprises one or both of a proximal seal assembly and a distal seal assembly arranged distally from the proximal seal assembly.

By way of non-limiting example, exemplary combinations applicable to A and C 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 embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. 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 embodiments 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. While compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, "from about a to about b," or, equivalently, "from approximately a to b," or, equivalently, "from approximately a-b") disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, 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 incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

The terms "proximal" and "distal" are defined herein relative to a surgeon or robotic surgical system having an interface configured to mechanically and electrically couple a surgical tool to a robotic manipulator. The term "proximal" refers to the position of an element closer to the surgeon or the robotic manipulator and the term "distal" refers to the position of an element further away from the surgeon or the robotic manipulator. Moreover, the use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward or upper direction being toward the top of the corresponding figure and the downward or lower direction being toward the bottom of the corresponding figure.

As used herein, the phrase "at least one of" preceding a series of items, with the terms "and" or "or" to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase "at least one of" allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases "at least one of A, B, and C" or "at least one of A or C" each refer to only A or only C; any combination of A and C; and/or at least one of each of A and C.

Claim 1:
A trocar assembly (<NUM>), comprising:
a housing (<NUM>) that defines a working chamber (<NUM>);
a cannula (<NUM>) extending distally from the housing and defining a lumen (<NUM>) that communicates with the working chamber;
a seal cartridge (<NUM>) at least partially arrangegable within the working chamber and including a bushing (<NUM>) extending distally into the lumen from a distal end (402b) of the seal cartridge; characterized by
a tertiary seal (<NUM>) immovably secured to the housing such that it remains in place within the working chamber distal to the seal cartridge, wherein the bushing extends through the tertiary seal when the seal cartridge is received within the working chamber.