Patent ID: 12232769

DETAILED DESCRIPTION

This description and the accompanying drawings that illustrate inventive aspects, embodiments, implementations, or applications should not be taken as limiting—the claims define the protected invention. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known circuits, structures, or techniques have not been shown or described in detail in order not to obscure the invention. Like numbers in two or more figures represent the same or similar elements. Headings are to assist the reader, and they form no portion of the description.

Further, this description's terminology is not intended to limit the invention. For example, spatially relative terms-such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like—may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., locations in space) and orientations (i.e., rotational placements in space) of a device in use or operation, in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the exemplary term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along and around various axes includes various special device positions and orientations. Also, geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round”, a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description.

In addition, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. And, the terms “comprises”, “comprising”, “includes”, and the like specify the presence of stated features, steps, operations, elements, and/or components but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups. Components described as coupled may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components.

Elements described in detail with reference to one embodiment, implementation, or application may, whenever practical, be included in other embodiments, implementations, or applications in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. Thus, to avoid unnecessary repetition in the following description, one or more elements shown and described in association with one embodiment, implementation, or application may be incorporated into other embodiments, implementations, or aspects unless specifically described otherwise, unless the one or more elements would make an embodiment or implementation non-functional, or unless two or more of the elements provide conflicting functions.

The term “flexible” in association with a part, such as a mechanical structure, component, or component assembly, should be broadly construed. In essence, the term means the part can be repeatedly bent and restored to an original shape without harm to the part. Many “rigid” objects have a slight inherent resilient “bendiness” due to material properties, although such objects are not considered “flexible” as the term is used herein. A flexible part may have infinite degrees of freedom (DOF's). Examples of such parts include closed, bendable tubes (made from, e.g., NITINOL, polymer, soft rubber, and the like) and helical coil springs, etc. that can be bent into various simple or compound curves, often without significant cross-sectional deformation. Other flexible parts may approximate such an infinite-DOF part by using a series of closely spaced components that are similar to a snake-like arrangement of serial “vertebrae”. In such a vertebral arrangement, each component is a short link in a kinematic chain, and movable mechanical constraints (e.g., pin hinge, cup and ball, live hinge, and the like) between each link may allow one (e.g., pitch) or two (4, pitch and yaw) DOF's of relative movement between the links. A short, flexible part may serve as, and be modeled as, a single mechanical constraint (joint) that provides one or more DOF's between two links in a kinematic chain, even though the flexible part itself may be a kinematic chain made of several coupled links. Knowledgeable persons will understand that a part's flexibility may be expressed in terms of its stiffness.

Aspects of the invention are described primarily in terms of an implementation using a da Vinci® Surgical System commercialized by Intuitive Surgical, Inc. of Sunnyvale, California. Knowledgeable persons will understand, however, that inventive aspects disclosed herein may be embodied and implemented in various ways, including teleoperated and, if applicable, non-teleoperated embodiments and implementations. Implementations on da Vinci® Surgical Systems are merely exemplary and are not to be considered as limiting the scope of the inventive aspects disclosed herein.

Seal Assembly

FIG.1is a diagrammatic, cross-sectional view of a seal assembly1for a minimally invasive surgical instrument. Proximal and distal orientation directions are as depicted as indicated by the arrows, and these orientations generally apply throughout this description and the associated figures. As shown inFIG.1, seal assembly1is positioned in the proximal end of cannula2(typically within a cannula bowl at the cannula's proximal end), and a portion of minimally invasive surgical instrument3is shown extending through seal assembly1and cannula2towards a surgical site4within a patient body. Surgical instrument3may optionally include various distal end components, such a surgical end effector3ahaving one or more mechanical DOFs and a wrist mechanism3bwith one or more mechanical DOFs that allows a surgeon to change end effector3a's orientation. Surgical instrument3typically inserts distally and withdraws proximally (i.e., reciprocates) through seal assembly1and cannula2many times as a surgeon operates the instrument during a surgical procedure. A latch piece (not shown) holds seal assembly1in place with reference to cannula2, as described in detail below.

As shown, seal assembly1includes a lower housing5and an upper housing6that when assembled together form a seal assembly housing. Lower housing5and upper housing6are shown as two separate pieces that are joined to make a complete single housing, and optionally the complete seal assembly housing is formed as a single piece. Seal assembly1further includes a wiper seal7and a fluid (e.g., gas, liquid) backflow prevention seal8. Several wiper seal7embodiments are described in detail below. Backflow prevention seal8may optionally be one of several forms of seals in which one or more slits are held closed (by inherent elastomeric material properties and by fluid pressure against the distal side of the seal) to prevent fluid backflow through the seal, but which are opened to allow fluid or an object to pass through the seal. Such seals include a single-slit “duckbill” form, an intersecting three-slit trifold form, an intersecting two-slit (a.k.a. “cross-slit” or “cruciform”) form, and an S-curved form. Other backflow prevention type seals may be used (e.g., trip doors, check valves, and the like).

In use, backflow prevention seal8closes as shown by the dashed line alternate position9, which prevents surgical insufflation gas or other fluid from escaping through the cannula when no surgical instrument is inserted into the cannula. When a surgical instrument is inserted into the cannula, backflow prevention seal8opens, and wiper seal7seals against the surgical instrument's shaft to likewise prevent insufflation gas or other fluid from escaping through the cannula. Thus wiper seal7and backflow prevention seal8cooperate to prevent insufflation gas or other fluid from escaping though the cannula during a surgical procedure, regardless of whether a surgical instrument is inserted into the cannula.

As shown inFIG.1, wiper seal7and backflow prevention seal8are sandwiched between lower housing5and upper housing6, although other configurations to hold the seals inside the seal assembly housing are possible, such as by the use of adhesive or other means of fixing the seals inside the housing. One or more optional spacers (not shown) may also be sandwiched between the upper and lower housings, as described below.

FIG.1further illustrates that seal assembly1may be configured to allow insufflation gas to enter the patient and to allow gas and suspended particulate matter (e.g., smoke) to be evacuated from the patient, both with and without an instrument inserted through the seal assembly. As shown, insufflation/evacuation gas10enters/exits a port11in seal assembly1. Port11is in the seal assembly housing-through lower housing5, as shown. Entering gas then flows between an inner side wall of lower housing5and an outer side wall of backflow prevention seal8to pass through the cannula or through a gap between surgical instrument3and the cannula's inner wall into the patient. Evacuation gas follows a reverse path. Details of an example configuration to allow insufflation/evacuation gas to pass though seal assembly1are given below. Two or more ports11may optionally be used to ensure a clear path exists to allow gas to pass through the seal assembly

In some embodiments, seal assembly1includes an instrument insertion guide12located on the proximal side of wiper seal7. Instrument insertion guide12helps guide the distil end of a surgical instrument into wiper seal7, for example so that the distal tip of instrument end effector3ais urged away from puncturing, tearing, snagging on, or otherwise damaging wiper seal7as the instrument is inserted. As described in detail below, in some embodiments instrument guide12is fixed with reference to the seal assembly housing (e.g., it is optionally formed with upper housing6as a single piece), and in other embodiments instrument guide is formed as a separate piece from the seal assembly housing, and as a separate piece it may be fixed or it may move with reference to the seal assembly housing.

In one inventive aspect, the combination of seal assembly1and the surgical instrument inserted through seal assembly1are considered an assembly. In another aspect, the combination of seal assembly1and cannula2are considered an assembly. In yet another aspect, the combination of seal assembly1, cannula2, and the surgical instrument inserted through both seal assembly1and cannula2are considered an assembly. In two additional aspects, the combinations of seal assembly1and cannula2, and of seal assembly1, cannula2, and the surgical instrument inserted through both seal assembly1and cannula2, are expanded to include a teleoperated medical device that controls the surgical instrument movements. Teleoperated medical devices are known, such as the da Vinci Xi® Surgical System commercialized by Intuitive Surgical, Inc., Sunnyvale, California, and such medical devices are also referred to by terms such as “surgical system” or “surgical robot”. As described above and below, the seal assembly is a component that allows the teleoperated medical device to carry out surgery by maintaining a proper gas-tight seal against a surgical instrument.

FIG.1Ais a diagrammatic, cross-sectional view of a portion of seal assembly1, similar toFIG.1but with several components omitted for clarity. Longitudinal and lateral directions are indicated by the labeled arrows, with longitudinal meaning a direction generally parallel to the instrument insertion and withdrawal axis, and lateral meaning a direction generally perpendicular to the instrument insertion and withdrawal axis.FIG.1Ashows surgical instrument3's shaft inserted through wiper seal7. Wiper seal7includes an inner sealing portion13and an outer flex portion14surrounding sealing portion13. Flex portion14allows sealing portion13to move distally and proximally along the longitudinal axis A as surgical instrument3is inserted and withdrawn through wiper seal7. Flex portion14also allows sealing portion13to move laterally (side-to-side) within the surgical instrument housing. Sealing portion13includes an upper annular face15and a lower annular face16, which is reverse from upper face15. Upper face15and lower face16intersect at annular wiper seal lip17to form a circular opening, and lip17seals against surgical instrument3's shaft outer surface18. Thus sealing portion13is relatively thick compared with flex portion14and so is more stiff than flex portion14. But, sealing portion13is sufficiently laterally flexible so that it can accommodate various instrument shaft diameters. In one embodiment, for example, wiper seal7effectively seals against surgical instrument shaft diameters in the range of 4.7 to 9.4 mm (referred to as a 5-8 mm range). In another example embodiment, wiper seal7effectively seals against surgical instrument shaft diameters in the range of about 9.7 to 14.2 mm (referred to as a 10-12 mm range). The wiper seal may be sized to accommodate various other diameter ranges, or it may be made of a material that is best suited to work with a single specific instrument shaft diameter.

As shown, upper face15is angled at an angle α with reference to instrument3's shaft, and lower face16is angled at an angle3with reference to instrument3's shaft. Another way to describe this is that angles α and β are angled with reference to a longitudinal axis A defined between the seal assembly's top and bottom, so that a surgical instrument inserts and withdraws along longitudinal axis A. Angle α is smaller (more acute) than angle β. Accordingly, upper face15's radial width is larger than lower face16's radial width. As surgical instrument3inserts distally through wiper seal7, contact between seal lip17and upper face15against shaft outer surface18tends to move sealing portion13distally. Likewise, as surgical instrument3withdraws through wiper seal7, contact between seal lip17and lower face16against shaft outer surface18tends to move sealing portion13proximally.

The relatively thicker sealing portion13, and the angles and/or radial widths of the upper face15and lower face16, provide several advantages. A typical thin-membrane septum seal has a uniform or near-uniform thickness, and so is subject to puncture and tearing by the instrument tip when an instrument is inserted. Sealing portion13's larger thickness with reference to flex portion14helps to guard against puncture or tearing as an instrument is first inserted, yet flex portion14provides an overall seal longitudinal and lateral flexibility similar to a thin septum seal's flexibility. As described below, in some configurations flex portion14provides superior flexibility characteristics for wiper seal7compared to a typical thin-membrane septum seal, since flex portion14can be made thinner because it is not contacted by the instrument. This overall flexibility accommodates longitudinal and lateral movements of the instrument shaft within the seal assembly during initial insertion, removal, and use. Upper face15's relatively steep angle α helps to guide the instrument tip into the hole formed by seal lip17, further reducing the risk of puncture or tearing. Seal portion13's thickness that results from lip17being compressed against the instrument shaft to form a thicker contact with the instrument shaft, along with seal portion13's increasing outward thickness, also helps to reduce or eliminate a problem of a portion of seal lip17being stretched into an oblong shape and separating from instrument shaft surface18if the shaft is moved laterally within these al assembly, which breaks the seal by creating an opening between the lip17and surface18. This situation is sometimes called a “cat-eye” condition due to the resulting seal opening shape, and it is more of a problem with instrument shaft diameters at the low end of a diameter range that a thin-membrane septum seal may accommodate. Because of sealing portion13's generally triangular cross-sectional shape, with an apex at lip17, the circular opening is easily expanded to accommodate various instrument shaft diameters, while the wiper seal function is preserved and sealing portion13's longitudinal flexing is significantly reduced. The generally smaller amount of material near the circular opening allows sealing portion13to be laterally compressed outward with relatively lesser resistance, and the generally larger amount of material away from the circular opening tends to cause sealing portion13to increasingly resist lateral compression outward as the circular opening further expands.

It can be seen that due to upper face15's relatively larger radial width compared with lower face16's radial width, relatively more of upper face15will contact instrument shaft surface18compared with lower face16as the instrument inserts and withdraws. Stated another way, the contact area between upper face15and the instrument shaft is larger than the contact area between lower face16and the instrument shaft. This contact causes friction between wiper seal7and instrument shaft surface18that is relatively higher as the instrument is inserted and relatively lower as the instrument is withdrawn. The lower friction during instrument withdrawal helps prevent wiper seal7from being pulled proximally as the instrument is fully withdrawn, and so helps prevent the wiper seal from inverting proximally through the upper opening in the seal housing. In view of the illustrative wiper seal embodiments shown in the drawings and described below, persons of skill in the art will understand that even if angles α and β are equal, or even if angle α is larger than angle β, sealing portion13optionally may be configured so that upper face15's radial width (i.e., contact area) is larger than lower face16's radial width in order to provide the relatively higher instrument insertion friction. Persons of skill in the art will understand that providing good sealing function with low friction (e.g., low enough to avoid a stick-slip condition) may be desirable, especially in teleoperated applications in which smooth control is desired as the instrument shaft constantly moves back and forth through the seal. But, such persons will also understand that providing a reasonable resistance to instrument insertion is desirable so that an instrument cannot inadvertently slip through the seal and injure the patient (e.g., due to the instrument's own weight during a manual laparoscopic procedure). The described sealing portion of the wiper seal offers such an increased insertion resistance friction, as well as acceptable insertion/withdrawal friction. Additional asymmetric insertion/withdrawal resistance features, as well as other wiper seal7features, are described in detail below.

As shown inFIG.1A, flex portion14is attached to an outer perimeter of sealing portion13longitudinally midway between upper face15and lower face16. Also, flex portion14is shown as being longitudinally aligned with lip17. Optionally, however, flex portion14is attached to sealing portion13's perimeter at various longitudinal positions, including extreme proximal and distal positions. Likewise, flex portion14is optionally positioned with various longitudinal relations with lip17. Examples of such longitudinal attachment and lip alignments are shown in detail below.

First Example

FIG.2is a cross-sectional elevation view of an illustrative surgical instrument seal assembly20. Seal assembly20includes a lower housing21aand an upper housing21bthat when assembled together form a generally cylindrical seal assembly housing21. As shown, during manufacturing lower housing21aand upper housing21bare first aligned with hex holes and interference pins, and then ultrasonic welding is used to secure lower and upper housings21a,21btogether. Other well-known permanent joining techniques may be used, such as permanent press fitting or use of adhesives. In one embodiment, the upper and lower housing pieces21a,21bare made of rigid polycarbonate, and optionally other rigid materials such as plastic or metal may be used.

Lower housing21aincludes a distal end22, which is inserted into a cannula bowl at the proximal end of a surgical cannula (not shown), and a proximal end23, which remains outside the cannula. Proximal end23is optionally generally larger than distal end22, and a relief surface24under proximal end23rests on and is held against the proximal end of the cannula. Lower housing21afurther includes an annular groove25in its outer wall surface26. An O-ring27is inserted into groove25, and when seal assembly20is inserted into the cannula bowl, O-ring27seals against the cannula bowl's inner wall surface to prevent insufflation gas from escaping between the cannula bowl's inner side wall and lower housing21a's outer side wall. O-ring27also allows the seal assembly to rotate within the cannula bowl while maintaining the seal between the seal assembly and cannula bowl, as discussed in more detail below. Persons of skill will understand that O-ring27is representative of various packing- or gasket-type seals that may be generally termed cannula seals and function to seal between the seal assembly's outer sidewall and the cannula bowl's inner sidewall, in some implementations allowing the seal assembly to rotate within the cannula bowl while maintaining the seal.

Lower housing21afurther includes an inner wall surface28, which tapers slightly laterally outward toward distal end22to allow increased lateral movement of the backflow prevention seal (see also e.g.,FIG.7in which an extended backflow prevention seal is shown). As shown inFIG.2, inner wall surface28is optionally slightly necked down near upper housing portion21b. The necking-down increases structural strength in the lower housing portion. Also as shown inFIG.2, several optional radially-inward-projecting ribs29are in this necked-down region. The ribs29help prevent the backflow seal's outer side wall surface from blocking gas flow as the gas passes between the housing's inner side wall and the backflow seal's outer surface side wall to enter or exit the surgical site via a port in the seal assembly.

As shown inFIG.2, lower housing21aalso includes an optional gas valve30, which includes a valve body31, a rotating valve member32, an external fitting33(e.g., a threaded Luer-Lock as shown), an internal fitting34(e.g., a Luer taper fitting as shown), and a gas channel30a. As shown, valve member32is snap-fit into and rotationally secured in valve body31by using annular retainer flange35. In some embodiments one or more optional support ribs30bare placed between the valve body31and the seal assembly housing21to provide additional structural strength to help prevent valve30from breaking away from housing21. As shown, the lower housing21a, valve body31, external fitting33, and support ribs30bare formed as an integral single piece, and optionally they may be formed as two or more pieces that are joined together. During a surgical procedure, an insufflation gas supply (not shown) may be coupled to fitting33,34, and valve member32is rotated to allow gas to flow inward into the seal assembly through channel30a. Alternatively, an evacuation gas sink (not shown; e.g., a vacuum source) may be coupled to fitting33,34, and valve member32is rotated to allow gas to flow outward from the seal assembly through channel30a.

Upper housing21bincludes an optional distally tapering annular funnel portion36, which leads to an optional annular instrument insertion guide37that extends distally toward the underlying wiper seal. The funnel portion36and instrument insertion guide37together define a circular hole38in upper housing21b, centered on the seal assembly's longitudinal centerline, through which an instrument is inserted. Hole38's diameter is larger than the hole in the underlying wiper seal, and the relation between hole38's diameter and the dimensions of the wiper seal's upper face surface is discussed in detail below. Funnel portion36helps guide a surgical instrument tip toward hole38, and instrument guide37helps align and guide the instrument tip for insertion through the underlying wiper seal.

Upper housing21boptionally includes one or more latch receiving features39that allow an object to be removably coupled to housing21. As shown, latch receiving features39are windows that allow obturator latches (not shown) to extend through and engage upper housing21b's inner surface to hold an obturator (not shown) fully inserted in the seal (seeFIG.15and associated text, below). The obturator latches engage under the perimeter that defines the window. The cannula, seal, and obturator together form an assembly that allows a surgeon to insert the cannula through the patient's body wall. It should be understood that latch receiving features39as shown are representative of many well-known latch mechanisms that will allow an obturator or other object to be removably coupled to the top of housing21. In another example, latches on a second seal assembly (not shown) hold the second seal assembly against the top of housing21. See e.g., U.S. Pat. No. 6,123,689 (showing a “reducer” seal that can be removably coupled to the top of a main seal assembly). The second seal assembly includes a wiper seal hole with a smaller diameter than the diameter of the hole of the wiper seal in housing21. The second seal assembly when coupled to housing21forms additional various combinations similar to combinations described elsewhere in this document.

As shown inFIG.2, a backflow prevention seal40is sandwiched between lower housing21aand upper housing21b. As depicted in this embodiment, backflow prevention seal40is a cross-slit seal. The thickness of each of backflow prevention seal40's folded sidewalls41tapers slightly toward seal40's distal end42. The thicker folded side walls41at seal40's proximal end help the backflow prevention seal to snap back to the closed position when an instrument is removed. The thinner folded side walls41at seal40's distal end provide increased side wall flexibility and resulting lower friction between seal40and an instrument when the instrument is inserted through seal40. The relatively thinner distal side walls41also help fluid backpressure against the side walls' outer surfaces keep the seal closed when an instrument is removed. Backflow prevention seal40is oriented within lower housing21aso that one of the sidewall41inward folds is aligned with gas channel34(i.e., the adjacent sidewall41outward folds are offset 45 degrees from gas channel34, as shown), in order to ensure sufficient gas flow past the folded sidewalls41, which are pushed against ribs29when an instrument is inserted through backflow prevention seal40. The interior of backflow prevention seal40is made longitudinally deep enough and laterally wide enough so that backflow prevention seal40does not interfere with movement of the overlying wiper seal as the wiper seal moves longitudinally and laterally. In an example embodiment, backflow prevention seal40is made of a medical grade elastomeric material, such as chlorinated polyisoprene or other rubber material, such as silicone, urethane, etc. Other suitable materials may be used.

FIG.2shows an optional annular spacer43positioned over backflow prevention seal40and sandwiched between lower and upper housing portions21a,21b. As described in more detail below, in some embodiments annular spacer43is combined as an integrally formed single piece with a latch that removably secures the housing21to a cannula. In some embodiments, spacer43is positioned over both the wiper and backflow prevention seals, so that the outer perimeters of the wiper and backflow prevention seals touch. As depicted, however, spacer43is positioned between the wiper and backflow prevention seals, which provides more longitudinal space between the wiper seal and the backflow seal's proximal end, and so allows the wiper seal to properly operate without contact interference from the backflow prevention seal. Spacer43may optionally include one or more annular bosses that compress either or both the backflow prevention seal and the wiper seal when the upper and lower housing pieces are secured together in order to ensure a gas-tight seal between each seal and the housing, and in order to prevent each seal from rotating within the housing.

As depicted, wiper seal44is positioned over annular spacer43so that wiper seal overlies (is proximal of) backflow prevention seal40. The instrument hole in wiper seal44is aligned over the intersection of the cross slits in backflow prevention seal40, so that an instrument passes through the centers of both the wiper and backflow prevention seals. Details of the wiper seal are discussed in more detail below.

As depicted, an optional annular spacer45is positioned over (proximal of) wiper seal44's outer perimeter. When used, annular spacer45helps distribute the pressure of upper housing21bagainst wiper seal44. In addition, annular spacer45may optionally include a wiper seal anti-inversion feature, described in more detail below.

Thus,FIG.2shows wiper seal44positioned over backflow prevention seal40in seal housing21, sandwiched along with optional spacers43and45between lower housing21aand upper housing21b.

Wiper Seal

FIG.3is an upper perspective view of an example wiper seal embodiment,FIG.3Ais a cross-sectional upper perspective view of the wiper seal embodiment shown inFIG.3, andFIG.3Bis a top plan view of the wiper seal embodiment shown inFIG.3.FIG.4is a lower perspective view of the wiper seal embodiment shown inFIG.3,FIG.4Ais a cross-sectional lower perspective view of the seal embodiment shown inFIG.3, andFIG.4Bis a bottom plan view of the embodiment shown inFIG.3. To avoid prolix description, the various features described with reference to this wiper seal embodiment, as well as the wiper seal features described above, apply to other wiper seal embodiments described above and below.

Referring toFIGS.2,3,3A,3B,4,4A, and4B, wiper seal44is generally annular and includes an annular outer perimeter portion45, an annular inner sealing portion46, and an annular flex portion47between perimeter portion45and sealing portion46. Perimeter portion45supports wiper seal44within housing21, so that sealing portion46can move longitudinally and laterally as an instrument shaft passing through wiper seal44moves inside housing21. As depicted, perimeter portion46has an optional small annular boss on its distal side, and various other optional configurations (e.g., annular boss on the proximal side, interrupted annular bosses or projections, etc.) may be used for mounting wiper seal44within the seal assembly housing. Sealing portion46functions as generally described with reference toFIGS.1and1A. It includes an annular upper face48and an annular lower face49that meet at circular seal lip50, which defines a hole through which a surgical instrument shaft is inserted and withdrawn. Seal lip50seals against the surgical instrument shaft's outer surface. Seal lip50may be formed as a single, rounded surface, or optionally it may be formed as other surface shapes, such as flat, corrugated, etc. Optionally, one or more small, discrete annular rings are placed on lip50for sealing against the instrument shaft. Sealing portion46is flexible, and so it accommodates various instrument shaft diameters (e.g., about 5-8.5 mm or about 10-12 mm)—the sealing portion46dimensions can be varied to suitably accommodate other diameter ranges). It can be seen that upper face48's radial width is larger than lower face49's radial width, and the angle between upper face48and an inserted instrument shaft is more acute than an angle between lower face49and the inserted instrument shaft.

Flex portion47surrounds sealing portion46, and it (i) allows sealing portion46to move distally and proximally (longitudinally) within the seal assembly, (ii) allows sealing portion46to move from side-to-side (laterally) within the seal assembly without significant distortion (thus reducing the “cat-eye” problem described above), and (iii) accommodates sealing portion46stretching radially outward when a large diameter instrument shaft is inserted. Thus the benefits of the various aspects of sealing portion46are combined with the benefits of flex portion47. As shown, flex portion47has a general annular folded bellows configuration, which is alternately described as an annular corrugation configuration, that includes one or more upper (proximally oriented) annular folds and/or one or more lower (distally oriented) annular folds, with annular grooves separating adjacent upper folds and adjacent lower folds (i.e., a groove is formed by the reverse of the fold). The folds act as hinges, although the flex portion47material between the folds may also stretch. In other embodiments, other suitable flex portion47configurations may be used, including for example flat (planar), annular diaphragms having constant or varying thickness.

In the depicted embodiment, flex portion47joins to sealing portion46at an inner upper annular fold51and joins to perimeter portion45at an outer upper annular fold52. There is a lower annular fold53between the upper annular folds51and52. As a result, a lower annular groove54is formed between sealing portion46and lower annular fold53, and an upper annular groove55is formed between the upper annular folds51and52. Support ribs56are positioned in lower annular groove54, and support ribs57are positioned in upper annular groove55. As shown, there are five each of support ribs56and57, and other numbers (e.g., three, four, six, or more) may be used. Individual support ribs56and57are generally positioned opposite one another on the obverse and reverse of wiper seal44, although they may be optionally placed at other mutually relative orientations. In addition, in some implementations the number of support ribs56may be different from the number of support ribs57. And, support ribs56and support ribs57may optionally be symmetrically or asymmetrically spaced within an annular groove. Symmetrical spacing of three or more support ribs tends to keep resistance to motion constant in all lateral directions, and asymmetrical spacing (or the use of only two support ribs oriented opposite one another) tends to favor motion in one or more lateral directions.

As shown inFIGS.4,4A, and4B, support ribs56are equally spaced in lower annular groove54. Each support rib56has two portions-a truncated semi-circular cylinder portion58that is joined at both sides to sealing portion46, and a web portion59that extends between the semi-cylinder portion58and lower annular groove54's outer sidewall. The semi-cylinder portions58of support ribs56are generally arranged to form a scalloped pattern around sealing portion46. As depicted, the semi-cylinder portions58are slightly separated from one another at sealing portion46, and they may optionally touch one another at sealing portion46.

Referring toFIGS.3,3A, and3B, support ribs57are equally spaced in upper annular groove55. Each support rib57has two portions-a truncated quarter-circle cylinder portion60that is joined at one side to upper annular groove55's outer sidewall, and a web portion61that extends between portion60's other side and upper annular groove's inner sidewall. It can be seen that support rib57's shape is similar to support rib56's shape, except that support rib57has only about one-half of support rib56's semi-cylindrical portion.

Both support ribs56and support ribs57may have other shapes. For example, support ribs57may have a semi-cylinder portion, or support ribs56may have a quarter-cylinder portion. Other support rib shapes include a single, smooth (e.g., S-shaped) or sharply-angled (e.g., zig-zag) folded piece between groove sidewalls. The tops of support ribs57and the bottoms of support ribs57may be truncated as shown as described, or may be generally parallel to seal44's lateral orientation.

It can be seen fromFIGS.2,4,4A, and4Bthat support rib56's attachment to lower annular groove54's outer sidewall extends below (distal) the level of sealing portion46. This configuration acts as an anti-inversion feature to help prevent sealing portion46from being pulled proximally during instrument withdrawal and unfolding upper annular fold51(i.e., inverting the seal). The support rib56configuration provides relatively small resistance to compression and relatively large resistance to extension. Therefore, the semi-cylinder portions58of support ribs56allow sealing portion46to stretch open to accommodate larger diameter instrument shaft diameters, which symmetrically compresses lower annular groove54. The semi-circular portions58also allow lower annular groove54to be asymmetrically compressed as sealing portion46moves laterally within flex portion47.

Thus both anti-inversion benefits and low resistance to compressing the annular groove are provided. The semi-cylindrical shape enables the support rib56to extend a relatively short distance with a relatively low resistance as the semi-cylinder's walls are pulled to straighten into a V-shape, and thereafter provide a relatively high resistance to further extension, which requires the support rib material itself to stretch. The semi-cylinder shape also enables the support rib56to almost fully collapse upon itself with little resistance. Artisans will understand, too, that the semi-cylinder shape's vertical walls allow for easy molding, so that the full wiper seal can be formed as a single, uniform piece. It can be seen that similar features and advantages exist in other support rib56configurations described above and below, as well as in the support rib57configurations as described below.

Further, although a specific embodiment has been described, many variations are possible, such as reversing the web and semi-cylinder orientation so that the web is closer to the sealing portion (depending on the groove configuration), altering the semi-cylindrical shape to include other curved or straight sides, etc. Therefore, in general terms the depicted support rib56can be described as having two walls, the first side of each wall being anchored to one of groove54's sidewalls, and the second side of each wall being joined together and anchored to the other one of groove54's sidewalls. And further, the level at which support rib56's walls join groove54's outer sidewall extends below (distal of) the level at which support rib56's walls join groove54's inner sidewall. Still further, although groove54's inner sidewall is depicted as being defined by sealing portion46, support ribs56may optionally be placed in any groove in flex portion47.

In some wiper seal46embodiments, a lubricant62, such as a medical grade silicone lubricant, is placed in one or more of the pockets formed between a support rib56's semi-cylindrical portion58and sealing portion46. As a surgical instrument is inserted and withdrawn through sealing portion46, sealing portion46's and flex portion47's flexing causes some lubricant62to be pushed out of the pocket, and it then migrates across lower face49to lubricate the contact between the surgical instrument shaft and sealing portion46. One suitable lubricant is NuSil Technology LLC's MED-420 (at ˜5,000 cP). Another suitable lubricant is NuSil's MED-361 (at ˜12,5000 cP), and other suitable lubricants with various viscosities may be used.

Referring now toFIGS.2,3,3A, and3B, it can be seen that due to upper annular groove55's sidewall angles with reference to a longitudinal axis, the support rib57orientations in upper annular groove55are generally reversed from the support rib56orientations in lower annular groove54. The level at which each support rib57attaches to upper annular groove55's outer sidewall extends above (proximal of) the level at which each support rib57attaches to upper annular groove55's inner sidewall (the top of which being where the flex portion47joins the sealing portion46). This configuration helps prevent sealing portion46from being pushed distally and possibly unfolding lower annular fold53during instrument insertion. Support rib57's quarter-cylindrical portion60and web61combination functions similarly to support rib56's semi-cylindrical portion58and web59combination, and similar configuration variations as described above are possible. It can be seen that each support rib57is somewhat larger than each support rib56. The quarter-cylindrical portion60functions to further reduce resistance to collapse compared with semi-cylindrical portion58, so that upper annular groove55easily collapses symmetrically as sealing portion46expands to accommodate a relatively larger instrument shaft diameter, and groove55easily collapses asymmetrically as sealing portion46moves laterally. In some embodiments, however, support rib57includes a semi-cylindrical portion (or variations) similar to support rib56. And, as for support ribs56in multiple lower annular grooves, if flex portion47includes multiple upper annular grooves, then support ribs57may be placed in any number of the upper annular grooves.

As referred to above, various other support rib configurations may be used in either the upper or lower grooves formed by the annular folds in the wiper seal's flex portion.FIG.3CandFIG.3Dare top and perspective views of a wiper seal46a, in which equally-spaced support ribs57aare positioned in a flex portion groove. Support ribs57aeach include a truncated cone section oriented in a longitudinal direction with the apex toward the bottom of the groove, and with the conic section walls coupled by small web portions to the groove's inner and outer sidewalls. The truncated cone is optionally right or oblique as shown, optionally circular as shown or other shape.

FIG.3EandFIG.3Fare top and perspective views of a wiper seal46b, in which equally-spaced support ribs57bare positioned in a flex portion groove. Support ribs57beach include a cylinder oriented in a longitudinal direction in the groove, and the cylinder walls are coupled by small web portions to the groove's inner and outer sidewalls. The diameters of the cylinders in support ribs57bare somewhat less than the groove's width at the top of the groove.

FIG.3GandFIG.311are top and perspective views of a wiper seal46c, in which equally-spaced support ribs57care positioned in such a groove. Similar to support ribs57b, support ribs57ceach include a cylinder oriented in a longitudinal direction in the groove, and the cylinder walls are coupled by small web portions to the groove's inner and outer sidewalls. The diameter of the cylinders in support ribs57care larger than the diameters of the cylinders in support ribs57b, the diameters being about the groove's width at the top of the groove.

FIG.3IandFIG.3Jare top and perspective views of a wiper seal46d, in which equally-spaced support ribs57dare positioned in a flex portion groove. In contrast to support ribs57a(FIGS.3C and3D), support ribs57dare truncated semi-cone sections, with one side edge of the cone section being coupled to the groove's inner sidewall, and the other side edge of the cone section being coupled to the groove's outer sidewall.

FIG.3KandFIG.3Lare top and perspective views of a wiper seal46e, in which equally-spaced support ribs57eare positioned in a flex portion groove. The configuration of each support rib57eis similar to the configuration of support ribs56(FIGS.4,4A, and4B), exceptFIGS.3K and3Lillustrate that the truncated semi-cylindrical configuration may be positioned in a top groove, and that the truncated semi-cylinders may be oriented with their openings radially outward.

FIG.3MandFIG.3Nare top and perspective views of a wiper seal46f, in which equally-spaced support ribs57fare positioned in a flex portion upper groove. The configuration of each support rib57fis similar to the configuration of support ribs57(FIGS.3,3A, and3B).

FIG.3OandFIG.3Pare top and perspective views of a wiper seal46g, in which equally-spaced support ribs57gare each positioned in a flex portion groove. The configuration of each support rib57gis a serpentine S-curve, with one side edge of the support rib being coupled to the groove's inner sidewall, and the other side edge of the support wall being coupled to the groove's outer sidewall. As depicted, the groove inner and outer sidewall locations at which the support rib attaches are at the same clock position centered on the wiper seal (the 12, 4, and 8 o'clock positions are shown), and the serpentine folds in the rib extend on both sides of this clock position.

FIG.3QandFIG.3Rare top and perspective views of a wiper seal46h, in which equally-spaced support ribs57hare each positioned in a flex portion groove. The configuration of each support rib57his a serpentine S-curve similar to support ribs56g(FIGS.30and3P), except that the serpentine folds in support ribs57hextend farther along the clock face (i.e., have a larger magnitude) than the serpentine folds in support ribs57g.

FIG.3SandFIG.3Tare top and perspective views of a wiper seal46i, in which equally-spaced support ribs57iare each positioned in a flex portion groove. The configuration of each support rib57iis a serpentine S-curve, with one side edge of the support rib being coupled to the groove's inner sidewall at one clock position centered on the wiper seal, and the other side edge of the support rib being coupled to the groove's outer sidewall an another clock position (e.g., displaced clockwise, as shown). As shown inFIGS.35and3T, the serpentine folds do not extend beyond the clock positions at which the support rib attaches to the sidewalls. And the clock positions at which each support rib attaches to the groove's inner side wall is different from the clock position at each support rib attaches to the groove's outer side wall. As shown, for example, one rib is attached to the inner side wall at the 12 o'clock position and to the outer side wall at the 1 o'clock position.

FIG.3UandFIG.3Vare top and perspective views of a wiper seal46j, in which equally-spaced support ribs57jare each positioned in a flex portion groove. The configurations of each support rib57jis similar to the configuration of support ribs57i(FIGS.3S and3T), except that one of the serpentine folds of the support rib (e.g., the fold closer to the sealing portion, as shown), extends beyond the clock position at which the support rib attaches to the sidewalls.

FIG.3WandFIG.3Xare top and perspective views of a wiper seal46k, in which equally-spaced support ribs57kare each positioned in a flex portion groove. The configurations of each support rib57kis similar to the configuration of support ribs57i(FIGS.35and3T), except that both of the serpentine folds of the support rib extend beyond the clock positions at which the support rib attaches to the sidewalls. This implementation, along with the implementation shown inFIGS.3U and3V, illustrate that the serpentine folds in the support rib are not necessarily symmetrical.

FIG.3YandFIG.3Zare top and perspective views of a wiper seal46m, in which equally-spaced support ribs57mare each positioned in a flex portion groove. Support ribs57mare a compound variation of support ribs generally described inFIGS.3S to3X. As shown, a longitudinally-oriented annular wall (i.e., a cylinder)57m-iis positioned between the groove's sidewalls, and then serpentine support ribs are coupled between the groove's inner sidewall and the annular wall, and between the annular wall and the groove's outer sidewall. As shown, for example, support rib portion57m-iiis coupled between the groove's inner sidewall and annular wall57m-i, and support rib portion57m-iiiis coupled between annular wall57m-iand the groove's outer sidewall. Each support rib portion57m-iiand57m-iiiis configured similarly to support ribs57i(FIGS.3S and3T), although other configurations may be used. The support rib configurations shown inFIGS.31and3Zillustrate that a web of interconnected support ribs can be positioned in one or more of the grooves in the wiper seal's flex portion. Implementations include any support rib configuration.

FIG.3AAandFIG.3ABare top and perspective views of a wiper seal46n, in which equally-spaced support ribs57nare each positioned in such a groove. As shown, support ribs57nare each straight, radial ribs between the groove's inner and outer sidewalls. Ribs57nprovide strong resistance to stretching, and so provide a good seal anti-inversion feature if, for example, positioned in the wiper seal flex portion's innermost lower groove, as shown. For relatively small radial motions of the wiper seal's sealing portion (e.g., from small increases in instrument shaft diameter or small lateral motions), ribs57nrely on their material's resilient compressibility. And for relatively larger radial motions of the wiper seal's sealing portion, ribs57rely on their material resiliently buckling.

Referring toFIG.2, it can be seen that wiper seal44is optionally sized so that upper annular fold51is generally below (distal of) the annular distal end of instrument insertion guide37. This configuration also helps to prevent wiper seal44from inverting when an instrument is withdrawn, because instrument insertion guide37helps prevent the relatively thick and less flexible sealing portion46from moving proximally as the instrument is withdrawn. Further, instrument insertion hole38's diameter is sized to inwardly overhang sealing portion46's outer perimeter so that the tip of an instrument being inserted will tend to contact sealing portion46's angled upper face48, and so be urged to pass through and not puncture or tear wiper seal44. As shown, for example, instrument insertion hole38's diameter is less than the outer perimeter diameter of upper face48, so that an inserted instrument tip will first contact upper face48of the thick sealing portion46. In this configuration, the instrument tip is guided away from contacting, and potentially damaging, the relatively thin flex portion47.

It can also be seen inFIG.2that there is sufficient space between lower annular fold53and backflow prevention seal42's inner folded sidewall, which allows sealing portion46to move distally and laterally without contacting the backflow prevention seal. In some implementations, such as those in which spacer43is made relatively thinner or is omitted, flex portion47may contact backflow prevention seal42's inner sidewall, and the angle of the flex portion47outer sidewall at or near the contact location still allows sealing portion46to move distally and laterally.

In an example embodiment, wiper seal44is made of a medical grade elastomeric material, such as chlorinated polyisoprene or other rubber material, such as silicone, urethane, etc. Other suitable materials may be used.

Second Example

FIG.5is a cross-sectional elevation view of a portion of another seal assembly embodiment 63, whose configuration, components, features, and variations are generally similar to the other example seal assembly embodiments in this description. As shown inFIG.5, seal assembly63includes wiper seal64(which includes sealing portion65) and backflow prevention seal66. The optional spacer (e.g.,FIG.2, element45) between the wiper seal and the upper housing is omitted from the depicted embodiment so that the top surfaces of wiper seal64are coplanar for molding.

As shown, sealing portion65includes an annular upper face67, which includes an upper (proximal) concave face portion68that smoothly transitions to a lower (distal) straight face portion69. Upper annular face67is made similar to upper annular face48(FIG.2). Instrument insertion hole70in housing71is sized so that instrument insertion guide72slightly inwardly overhangs upper concave face portion68, as described above. In addition, the upper annular fold73of wiper seal64's flex portion is in contact or near contact with instrument insertion guide72's distal end. Annular fold73's top surface is shown as optionally flat, and other top surface shapes may optionally be used to allow sealing portion65to smoothly move laterally underneath insertion guide72's distal end.

Referring toFIG.2, despite the advantages of the relation between insertion guide37's distal end and sealing portion46, if an instrument is initially inserted at an extreme off-longitudinal-axis orientation (e.g., an operating room person may rest the tip in the instrument insertion hole and then tilt the instrument up to align it for insertion; see cg.FIG.7), the tip may enter the small gap between the top of upper annular fold51and the bottom of instrument guide37. It can be seen that in contrast toFIG.2's wiper seal44and its sealing portion46, inFIG.5's wiper seal64the upper concave face portion68(and upper annular fold73) is extended proximally to be close to or in contact with the upper housing71and its insertion guide72. This contact or near contact helps prevent an off-axis-inserted instrument tip from contacting the flex portion outside of sealing portion65, and it helps urge the off-axis-inserted instrument's tip through the wiper seal. Concave face portion68's relatively more acute angle with reference to the seal assembly's longitudinal axis also helps prevent the instrument tip from catching on the sealing portion, and so urges the tip through the wiper seal without damaging the seal.

Third Example

FIG.6is a cross-sectional elevation view of a portion of another seal assembly embodiment 74, whose configuration, components, features, and variations are generally similar to the other example seal assembly embodiments in this description. As shown inFIG.6, seal assembly74includes wiper seal75(which includes sealing portion76) and backflow prevention seal77. It can be seen that in contrast to wiper seal64(seeFIG.5) and its sealing portion65, wiper seal75and its sealing portion76are relatively deeper (i.e., longitudinally extended). Backflow prevention seal77is the same depth as backflow prevention seal40(FIG.2), and in some embodiments it may optionally be made deeper to accommodate wiper seal75and its longitudinal movement. The optional spacer (e.g.,FIG.2, element45) between the wiper seal and the upper housing is omitted from the depicted embodiment.

Similar to sealing portion65(FIG.5), sealing portion76includes an annular upper face78, which includes an upper concave face portion79that smoothly transitions to an annular lower straight face portion80. Lower straight face portion80is formed to have a steeper angle than—and so has a radial width (surface area) larger than-straight face portion69(FIG.5) with reference to an inserted surgical instrument (i.e., the face angle is more acute with reference to the seal assembly's longitudinal axis). Therefore, upper annular face78is relatively radially wider than upper annular face67(FIG.5). Annular lower straight face portion80's steep angle further helps urge an instrument tip through wiper seal without puncturing or tearing the relatively soft material used to form the wiper seal. As shown inFIG.6, the mutually relative configurations of the instrument insertion guide and wiper seal are similar to the embodiment shown in and described with reference toFIG.5.

Referring toFIGS.2,5, and6, it can be seen that at the center of the wiper seal, the thick sealing portion's upper face can have many surface variations, which include flat, concave, and possibly convex annular surfaces, along with various combinations of such surfaces that blend into one another. Although not shown, it is envisioned that the sealing portion's lower face may have similar variations.

Fourth Example

FIG.7is a cross-sectional elevation view of a portion of another seal assembly embodiment 81, whose configuration, components, features, and variations are generally similar to the other example seal assembly embodiments in this description. Seal assembly81includes a seal assembly housing82, a backflow prevention seal83, a wiper seal84proximal of backflow prevention seal83, and an instrument insertion guide85positioned over (proximal of) wiper seal84. Instrument insertion guide85is fixed to the seal assembly housing and defines an instrument insertion hole86in housing82. Insertion guide may be formed as an integral piece of the seal assembly housing's upper portion, as shown, or it could optionally be formed as a separate that is then mechanically or adhesively joined to the upper housing.

As shown inFIG.7, instrument insertion guide85extends distally into seal assembly housing82much farther (more distal) than, for example, instrument insertion guide37extends into seal assembly housing21(FIG.2). A distal end of the instrument insertion guide extends to a depth distal of the location at which the wiper seal is coupled to the seal assembly housing. As depicted, instrument insertion guide85extends to a depth that is about 4/10ths of the distance (it could be more or less, such as 3/10ths or 5/10ths) between seal assembly housing82's proximal end87and distal end88. Stated another way, the instrument insertion guide85extends distally past the plane of the wiper seal's most proximal portion. Stated yet another way, in the wiper seal's flex portion upper groove, the groove's outer sidewall is longer than its inner sidewall (e.g., about two times longer or more) so that the wiper seal's sealing portion is to be near a longitudinal center of the sealing assembly. Instrument insertion guide85's extended length further ensures that the distal tip of an instrument inserted into seal assembly81will contact the upper annular face88of wiper seal84's sealing portion89at an angle relatively more acute than an angle the tip would contact the upper annular face if the instrument insertion guide had a shorter length, such as is illustrated inFIGS.5and6. This enhanced instrument guide feature is illustrated by considering the insertion orientation of one surgical instrument90, as shown inFIG.7. The surgical instrument at insertion orientation90ais about what it would be if the length of the instrument insertion guide was as shown in, for example,FIG.2. Thus surgical instrument90s's distal tip91at orientation90acould contact the wiper seal's upper annular face at a steep angle, which increases the risk that tip91will puncture or tear the wiper seal, and which in some instances may even urge tip91away from passing through the wiper seal due to tip91's contact angle with the annular face. In contrast, surgical instrument orientation90bis limited by instrument insertion guide85's length, so that surgical instrument90's distal tip91will contact the wiper seal's upper annular face at a relatively more acute angle, thus reducing the risk that tip91will puncture or tear the wiper seal, and which ensures that the annular face will even more effectively urge tip91towards passing through the wiper seal. As shown, sealing portion89has a configuration similar to sealing portion65(FIG.5), and it should be understood that various sealing portion configurations may be used.

As shown inFIG.7, the lengths of backflow prevention seal83and wiper seal84are extended to accommodate instrument insertion guide85's increased length. Seal assembly housing81's overall length is generally limited by the depth of the cannula bowl (not shown; seeFIG.2) in which it is inserted. To prevent damage to backflow prevention seal83during normal handling, and to prevent the cannula bowl inner surface from interfering with backflow prevention seal83's function when an instrument is inserted, backflow prevention seal83's length is configured so that its distal end92does not extend past seal assembly81's distil end88when backflow prevention seal83is in the closed (sealed) position. Wiper seal84's sealing portion89may optionally be extended as far as possible into backflow prevention seal83, so that backflow prevention seal83does not interfere with the proximal-distal and lateral movement of sealing portion89and its adjacent flex portion. As shown inFIGS.7and3B, the outer surface of the flex portion's upper annular groove93may optionally be configured with thick, longitudinal stiffening ribs94to provide additional support for wiper seal84's flex portion and to keep the wiper seal from inverting proximally at these outer walls. In one illustrative embodiment, each stiffening rib94is positioned between adjacent upper support ribs95with a width that is approximately one-half the distance between the support ribs. More or fewer stiffening ribs94may be used at various positions.

In addition, optional support ribs96may be placed around instrument insertion guide85's outer surface, extending radially outward, to provide increased support for instrument insertion guide85. The distal ends97of the radial support ribs96are optionally configured to have the same length as instrument insertion guide85, so that the inner annular fold of the flex portion contacts both instrument guide85's distal end98and the support ribs96's distal ends97when an instrument is withdrawn through wiper seal84. The distal ends97act as both a proximal longitudinal motion limit stop and a lateral motion guide surface. Thus sealing portion89's proximal range of motion is limited regardless of its lateral position within the seal assembly housing. This proximal motion limit keeps the wiper seal from temporarily or permanently catching on the insertion guide when an instrument is removed, especially if the instrument is removed in a direction off the longitudinal axis.

Optional radial support ribs99may be placed under seal assembly81's proximal end87to provide additional structural support. Support ribs96and99may optionally be blended together to form an approximately L-shaped support brackets that extend under the upper housing's top surface and then distally along the outside of instrument guide85.

Fifth Example

FIG.8is a cross-sectional elevation view of a portion of another seal assembly embodiment 100, whose configuration, components, features, and variations are generally similar to the other example seal assembly embodiments in this description.FIG.8shows that seal assembly100includes se-al assembly housing101(which includes lower housing101aand upper housing101b), backflow prevention seal102positioned distally within lower housing101a, spacer (and optional latch mechanism)103positioned over (proximal of) backflow prevention seal102, wiper seal104positioned over (proximal of) spacer103, and upper housing101bpositioned over (proximal of) wiper seal104. Upper housing101bincludes an integrally formed, short, fixed instrument insertion guide105and support ribs106extending radially outward from insertion guide105underneath the top of proximal housing101b, similar to the seal assembly20configuration illustrated inFIG.2.

Wiper seal104is configured generally similar to wiper seal84's configuration, as illustrated inFIG.7. In contrast to the seal assembly illustrated inFIG.7, however, seal assembly100includes a second, floating instrument insertion guide107that is attached to wiper seal104's sealing portion108, so that instrument insertion guide107moves proximally-distally (longitudinally) and also laterally as sealing portion108moves.

As depicted inFIG.8, floating instrument insertion guide107is generally cylindrically shaped, with a proximal end109, a distal end110, an inner side wall surface111, and an outer sidewall surface112. In one embodiment, instrument insertion guide107's proximal end109optionally touches, or nearly touches, the bottoms of radial support ribs106, which prevent instrument insertion guide107's further proximal movement (and wiper seal104from inverting, as described above) and provide a lateral movement guide surface for insertion guide107. Thus proximal end109may smoothly slide laterally while being kept at its proximal range-of-motion limit by the bottoms of radial support ribs106. The distal end of fixed instrument insertion guide105may optionally be made flush with the bottoms of support ribs106, or it may extend beyond the bottoms of support ribs106. Alternatively, an optional spacer may be positioned between upper housing101band distal end109, so that the spacer limits floating instrument insertion guide107's proximal travel. (See e.g.,FIG.13A, anti-inversion piece152, or a similar ring without flexible fingers154, is an illustrative spacer.) Instrument insertion guide105inwardly overhangs floating instrument insertion guide107proximal end109, so that the diameter of instrument insertion hole114in proximal housing101ais less than the diameter defined by floating instrument insertion guide107's inner sidewall surface111at proximal end109. Thus floating instrument insertion guide107may move laterally to its extreme range of motion without distal end109being exposed through hole114, so that no portion of the instrument being inserted will catch on a portion of distal end109during instrument insertion.

Floating instrument insertion guide107's distal end110is in contact with the outer perimeter of wiper seal104's sealing portion108. As shown, distal end110is in contact at or near upper annular fold115, where sealing portion108joins wiper seal104's flex portion.FIG.8shows that floating instrument insertion guide107's outer sidewall112may optionally extend below the top of annular fold115to provide increased support for the contact between wiper seal104and floating instrument insertion guide107(cutouts, or other distal end110configurations, to accommodate support ribs in the flex portion may be included, depending on the support rib configuration). Likewise,FIG.8shows that floating instrument insertion guide107's inner sidewall111may optionally extend below the top of annular fold115to provide a smooth transition between sidewall111and sealing portion108's upper face116. As depicted, an outer portion of sealing portion108's upper face116is concave, as described above, to further provide a smooth surface transition between sidewall111and upper face116. In some embodiments, floating instrument insertion guide107merely rests against wiper seal104and is held in place by the configuration of the assembly. In other embodiments, floating instrument insertion guide107may be secured to wiper seal104by, for example, an adhesive or a bonding process (e.g., using Loctite® 4011™), or by mechanical attachment. In addition, skilled artisans will understand that the instrument insertion guide may be attached at various locations on the wiper seal that will allow the insertion guide to move laterally within the seal assembly housing.

As shown inFIG.8, floating instrument insertion guide107's inner sidewall111is optionally made slightly concave to help guide an instrument tip towards, and provide a smooth transition to, the upper surface of wiper seal104's sealing portion108. In other embodiments, however, other floating instrument insertion guide inner sidewall configurations (e.g., flat, convex, compound, etc.) may be used as illustrated below.

Sixth Example

FIG.9is a cross-sectional elevation view of a portion of another seal assembly embodiment 117, whose configuration, components, and variations are generally similar to the other example seal assembly embodiments in this description.FIG.9shows seal assembly117includes seal assembly housing118(which includes lower housing118aand upper housing118b), backflow prevention seal119positioned distally within distal housing118a, spacer (and optional latch mechanism)120positioned over (proximal of) backflow prevention seal119, wiper seal121positioned over (proximal of) spacer120, and proximal housing118bpositioned over (proximal of) wiper seal121. Seal assembly117also includes floating instrument insertion guide122, which along with the various other associated seal assembly117components is generally configured as described with reference to seal assembly100(FIG.8).FIG.9illustrates alternate configurations of the floating instrument insertion guide's interior sidewall.

As shown inFIG.9, floating instrument insertion guide122's inner sidewall123includes an upper portion124adjacent its proximal end125, and upper portion124smoothly transitions to a lower portion126adjacent its distal end127. Upper portion124is slightly concave (or optionally straight or convex), and lower portion126is flat (or optionally concave or convex). Lower portion126's cylindrical, vertical side walls form a relatively less acute angle transition to wiper seal121's sealing portion upper face128than, for example, the transition illustrated inFIG.8. Nevertheless, it has been found that lower portion126's vertical sidewalls limit the insertion orientation angle of the instrument itself, and the result is improved instrument tip insertion through wiper seal121with less tendency for the instrument tip to catch on upper face128. Thus it can be seen that many floating instrument insertion guide inner sidewall configurations exist. In addition, it is possible to optionally similarly configure the inner sidewalls of fixed instrument insertion guides (see e.g., instrument insertion guide85inFIG.7) in the seal assembly housing.

Seventh Example

FIG.10is a cross-sectional elevation view of a portion of another seal assembly embodiment 129, whose configuration, components, features, and variations are generally similar to the other example seal assembly embodiments in this description.FIG.10shows seal assembly129includes seal assembly housing130(which includes lower housing130aand upper housing130b), backflow prevention seal131positioned distally within lower housing130a, spacer (and optional latch mechanism)132positioned over (proximal of) backflow prevention seal131, wiper seal133positioned over (proximal of) spacer132, and upper housing130bpositioned over (proximal of) wiper seal133. Seal assembly129also includes floating instrument insertion guide134, which along with the various other associated seal assembly129components is generally configured as described with reference to seal assemblies100(FIG.8) and117(FIG.9).FIG.10illustrates alternate configurations of the floating instrument insertion guide's distal end135and corresponding wiper seal portion.

As shown inFIG.10, floating instrument insertion guide134's distal end135includes an annular groove136between the insertion guide's inner and outer sidewall surfaces. Wiper seal133includes an annular boss137that extends upward (proximally) from the location at which wiper seal133's sealing portion joins to its flex portion. Annular boss137fits inside annular groove136to help secure floating instrument insertion guide134to wiper seal133. In the depicted embodiment, the deepest (most proximally oriented when assembled) part of annular groove136is tapered so that sufficient material thickness exist; between the groove sidewall and the insertion guide's inner sidewall, and the interior of the corresponding proximal portion of annular boss137is beveled to match the tapered shape. A small clearance exist; between annular groove136and annular boss137to ensure that the distal end134aof instrument guide134contacts the upper annular face133bof wiper seal133's sealing portion133ato form a smooth surface transition between the two components. The clearance also ensures sufficient space for a bonding adhesive to be used to bond annular boss137and insertion guide134. An optional mechanical attachment may be used. This mating configuration between wiper seal133and floating instrument insertion guide134helps resist lateral forces from an instrument tip that may separate wiper seal133and instrument insertion guide134as an instrument is inserted into and through seal assembly129.

Seal Assembly Latch

FIG.11is an upper perspective view of a combination spacer and latch piece138for a seal assembly, which includes a ring-shaped spacer portion139and two latches140positioned opposite one another at the outer perimeter of spacer portion139. At spacer portion139's inner perimeter, a raised annular boss141extends proximally. As shown, spacer portion139and latches140are integrally formed as a single piece. In one example embodiment, the combination spacer and latch piece138is made of flexible polycarbonate, and other materials may be used if they offer suitable flexibility for the U-shaped flexures, described below. And, although two latches140are shown, other embodiments include a single latch and three or more latches. As discussed below, a single latch in accordance with the disclosed aspects will effectively latch the seal assembly to the cannula.

The spacer portion139functions as generally shown and described above (FIG.2no.43;FIG.8no.103;FIG.9no.120;FIG.10no.132). When spacer and latch piece138is assembled into a seal assembly, annular boss141is aligned between portions of the upper and lower seal assembly housings, so that the wiper seal's perimeter portion is sandwiched and compressed between the upper housing piece and the annular spacer portion139, and the backflow prevention seal's perimeter portion is sandwiched and compressed between the lower housing piece and the annular spacer portion139. The slight compression forms a gas-tight seal. Annular boss141may optionally be positioned at or near spacer portion139's outer perimeter, or between its inner and outer perimeters. In some implementations, the annular boss may extend distally. Two or more annular bosses may be used in various combinations.

FIG.12is a cross-sectional view of a latch portion140of spacer and latch piece138within a seal assembly coupled to a cannula. Latch portion140includes a U-shaped resilient flexure142that joins to spacer portion139at one end. At the other end, flexure142joins to a middle area of latch piece143. Above (proximal of) the middle area at which flexure142joins latch piece143is a finger tab144patterned to assist grip (e.g., grip by a surgical-glove-covered digit). Below (distal of) the middle area is a latch tab145that includes a finger146that extends laterally inward towards spacer portion139, and below finger146is a catch147oriented inward toward spacer portion139. Catch147optionally includes an inward-oriented distal beveled lead—in surface148to help catch147flex radially outward and then latch to the cannula as the seal assembly is pressed into the cannula bowl.

In use, latch piece143pivots around a fulcrum defined by flexure142, so that as finger tab144moves radially inward, latch tab145moves radially outward. When the seal assembly is inserted into a cannula bowl at the proximal end of a cannula, lead-in surface148contacts cannula bowl flange149a, which causes latch tab145to move outward. Once catch147is distal of cannula bowl flange149a, flexure142returns latch tab145to its original position, and so positions catch147under cannula bowl flange149a, thus removably latching the seal assembly to the cannula149. Latch portion140is sufficiently resilient to latch the cannula bowl without squeezing the finger tabs144when the seal assembly is pressed into the cannula bowl, and it is sufficiently stiff to prevent the seal assembly from disengaging from the cannula bowl until the finger tabs144are squeezed.

As shown inFIG.12, when the seal assembly is latched to a cannula bowl, cannula bowl flange149aand seal assembly housing relief surface (shoulder)150are positioned between catch147and finger146's bottom (distal) surface. As a result, if an attempt to remove the seal assembly from the cannula bowl is made, catch147contacts the bottom of cannula flange149a, and the top (proximal) surface of seal assembly housing relief surface (shoulder)150contacts the bottom surface of finger146, which keeps the seal assembly from being removed from the cannula bowl. An advantage of this latch configuration is that the retention force is kept between catch147and finger146without being transferred to flexure142. And in addition, latch tab145's design allows the seal assembly to rotate around the longitudinal axis without limit inside the cannula bowl, as described in more detail below. Further, if only one of the two latch portions is engaged with the cannula flange, then a proximal pulling force on the seal assembly will tend to rotate the seal assembly around the engaged latch portion, then the bottom of the seal assembly housing (see e.g.,FIG.2, no.22) will contact an inner sidewall of the cannula howl, and the seal assembly is prevented from being removed from the cannula. Thus both latch portions140must be released by squeezing finger tabs144to remove the seal assembly from the cannula. Inadvertent latch release may be further prevented by positioning physical guards near the finger tabs144, as described below (see e.g.,FIG.13B, elements157).

Anti-Inversion Piece

FIG.13Ais a top perspective view of an example seal assembly151with a top portion of its housing removed to show an example embodiment of an optional seal anti-inversion piece152positioned over (proximal of) the wiper seal, andFIG.13Bis a top perspective view of seal assembly151with the top portion of its housing in place. As shown inFIGS.13A and13B, anti-inversion piece152's outer perimeter area153functions as a spacer between a top perimeter surface of the wiper seal and a bottom surface of the top portion of the seal assembly housing (see e.g.,FIG.2, spacer45). Anti-inversion piece152includes several (16are shown) anti-inversion fingers154that extend from outer perimeter area153radially inward, and the tips155of fingers154define a center hole156, through which a surgical instrument is inserted. Hole156's diameter may optionally be larger than, equal to, or less than the smallest diameter surgical instrument shaft that seal assembly151is designed to accommodate. As depicted, fingers154are optionally formed in a spiral pattern, and other patterns (e.g., extending straight inward, extending inward at an angle, etc.) may be used. In a more general sense, therefore, the fingers may optionally be configured in two ways-one type in which the tips of the fingers are radially aligned with the finger hinge points near the outer perimeter, and another type in which the tips of the fingers are radially offset (clockwise or counter clockwise) from the finger hinge points near the outer perimeter.

Anti-inversion piece152is flat and is made of a stiff but resilient material, so that if the fingers154are flexed downward (distally) when an instrument is inserted, anti-inversion piece152returns to its flat configuration when the instrument is withdrawn. Unlike straight, radial fingers, the spiral pattern fingers can move radially outward and overlap to avoid being caught in a portion of an instrument being withdrawn. Other finger patterns, including straight, radial fingers, may be used, as described below.

As shown inFIG.13B, the upper portion of the seal assembly housing extends radially inward part-way over the fingers, so that only the tips155are visible through the instrument insertion hole in the top of the seal assembly housing. In operation, the fingers154are sufficiently long to easily flex downward when a surgical instrument is inserted in the seal assembly. When the instrument is withdrawn, the fingers prevent the underlying wiper seal from inverting through the instrument insertion hole at the top of the seal assembly housing. By allowing the tips155to extend slightly into a longitudinal cylinder defined by the housing's instrument insertion hole, if one or more tips155catch on a part of the instrument (e.g., a wrist assembly or surgical end effector), then the tip(s) may flex slightly upward (proximally) through the hole to allow the instrument to be withdrawn. The upper housing's inner perimeter that defines the hole acts as a fulcrum for the tips155when the instrument flexes the tips upwards. The tips155are optionally rounded and/or lubricated to reduce friction between the tips and the surgical instrument shaft during normal use. In one embodiment, the anti-inversion piece152is made of high-density polyethylene with two percent siloxane (i.e., HDPE with infused silicon for lubricity). Other flexible, durable plastics may be used.

FIG.13C, is a plan view of anti-inversion piece152. As shown, 16 equal-length spiral-pattern fingers154are defined by 16 corresponding spiral-pattern cuts154a. A crack-stop hole154bis defined at the outward radial end of each cut154ato help prevent material failure as the fingers flex distally and are displaced radially outward. Such crack-stop holes may optionally be used on all anti-inversion piece embodiments. As shown, the tips155of each of the fingers154are generally squared off, and they may optionally be rounded to help prevent catching in surgical instrument components and reduce friction against the instrument shaft.

FIG.13Dis a plan view of an anti-inversion piece152a. As shown, anti-inversion piece152aincludes several spiral-pattern fingers154cthat extend radially inward from outer perimeter153a, and each spiral pattern finger154cis divided into shorter spiral pattern subfingers154d. As shown inFIG.13D, there are four spiral pattern fingers154c, each divided into four subfingers154d. The cuts that define the spiral pattern fingers154cextend radially outward to about 80-percent of anti-inversion piece152a's radius, and the cuts that define the spiral pattern subfingers154dextend radially outward to about 55-percent of anti-inversion piece152a's radius. Other relative lengths between the fingers and subfingers may be used. For example,FIG.13Eis a plan view of an anti-inversion piece152b. As shown inFIG.13E, the cuts that define the spiral pattern fingers154eextend radially outward to about 80-percent of anti-inversion piece152b's radius, and the cuts that define the spiral pattern subfingers1541extend radially outward to about 40-percent of anti-inversion piece152b's radius. Thus in one aspect the length of cuts that define the subfingers is from about 40- to 55-percent for the radius, although other cut lengths may be used to define the fingers and subfingers. The spiral-patterned fingers and subfingers act to splay and twist out of the way when an instrument is inserted or withdrawn, and the subfingers' shorter range of motion during such splay and twist keeps the bent subfingers over the wiper seal sealing portion's upper annular face, which protects the annular face from sharp instrument tips.

Although spiral pattern features in the anti-inversion piece have desirable characteristics, in other anti-inversion piece embodiments straight inward radial fingers may optionally be used. For example,FIG.13Fis a plan view of anti-inversion piece152cwith several equal-length straight fingers154gthat extend radially inward from outer perimeter area153b. There are 18 fingers154gshown inFIG.13F, and other numbers of fingers may optionally be used. For example,FIG.13Gshows an implementation in which 12 straight radial fingers are used, andFIG.13Hshows an implementation in which 6 straight radial fingers are used. As shown inFIGS.13F,13G, and13H, the radial cuts that define the fingers are relatively narrow, so that as the number of radial fingers decreases, the width of each individual finger correspondingly increases. Also,FIGS.13G and13Hillustrate that the inner tips155a(FIG.13G) and155b(FIG.13H) may be rounded to help prevent catching on an instrument component as it is inserted and withdrawn through the anti-inversion piece, and to reduce friction against the instrument shaft.

In addition, a finger and subfinger configuration as described above with reference to spiral-patterned fingers inFIGS.13D and13Emay optionally be used for radially straight fingers. For example,FIG.13Ishows an anti-inversion piece152dthat includes several straight fingers154hthat extend inward from an outer perimeter area153b, and each individual finger154his divided into subfingers154i. As shown, anti-inversion piece152dincludes four fingers154h, and each finger154hincludes three subfingers154i. The cuts that define the fingers154hextend to about 80-percent of anti-inversion piece152d's radius, and the cuts that define the subfingers154iextend to about 55-percent of anti-inversion piece152's radius. Again, various other cut lengths may be used to define the fingers and subfingers.

Other Housing Features

FIG.13Balso illustrates two additional seal assembly housing features. As shown, seal assembly151's housing optionally includes guards157that extend radially outward from the housing on either side of each latch finger tab144. Guards157help prevent the associated finger tab144from being inadvertently pressed inward to release the seal assembly from the cannula.

Also as shown inFIG.13β, seal assembly151's housing optionally includes two latch windows158on its top surface, and these windows are used to optionally latch another medical device, such as the obturator described below, to the housing's top surface, as explained above with reference toFIG.2and in more detail below. In addition, housing151's top surface151ais smooth and level along the arcs between the windows158. This top surface configuration allows the component to be radially centered on the housing and rotated clockwise or counter-clockwise until the component's latches drop into the windows158.

Obturator

FIG.14is a perspective view of an example obturator159, which includes a shaft160, a tip161at shaft160's distil end, and a proximal portion162at shaft160's proximal end. Two latches163are positioned on opposite sides of proximal portion162, and these latches163are used to secure obturator159to the top of a seal assembly. Materials used for the obturator are similar to those used for the seal assembly.

FIG.15Ais a cross-sectional view of a proximal portion164of an example obturator coupled to the top of a seal assembly165. As shown inFIG.15A, the obturator shaft166extends through seal assembly165. Two resilient latch flexures167are positioned on opposite sides at obturator shaft166's proximal end. At the far ends of the flexures167are catches168, which insert through windows169in seal assembly164's top surface and catch underneath the lips in the top portion of the seal assembly housing that define each window169. The latches hold the obturator firmly against the seal assembly. Catches168are optionally beveled so that the obturator can be latched to the seal assembly by pressing it distally after the obturator is rotated to allow the catches to drop into the windows158. The latch flexures167also include finger tabs170, and by compressing the finger tabs170radially inwards, the catches168move radially inwards to allow the obturator to be removed from the seal assembly.

FIG.15Bis a cross-sectional view of the proximal portion164of the example obturator coupled to the top of seal assembly165, taken at right angles to the view inFIG.15A. The depicted seal assembly cross section is similar to the one illustrated inFIG.12.FIG.15Bshows that obturator proximal portion164includes two distally projecting interference tabs164a. When the obturator is fully seated on the seal assembly's top surface, each of these interference tabs164comes between the upper portion165aof the seal assembly housing and the finger tab144, thus preventing finger tab144from being pressed radially inward and consequently preventing the combination of the seal assembly and the obturator from being unlatched from the cannula flange149a.

Referring toFIGS.12and15B, it can be seen that the latch piece143features allow the seal assembly to be securely latched to cannula149, and also allow the seal assembly and any component coupled to it to rotate without limit around longitudinal axis A inside cannula149. The cannula bowl flange149aand seal assembly housing relief surface (shoulder)150are held between latch piece143's finger146and catch147, and cannula flange149a's smooth underside allows catch147to move without interference, while the O-ring165bmaintains a gas-tight seal between the seal assembly and the cannula bowl's inner wall. One or more optional stops (not shown) may be placed on cannula flange149a's underside to limit the amount that the seal assembly can rotate around the longitudinal axis in the cannula bowl. The seal assembly's ability to rotate in the cannula bowl provides an ability to orient the seal assembly's fluid entry/exit valve to any desired orientation, or to reorient the valve, as needed during use, as shown below. And, the ability to rotate the seal in the cannula bowl allows the seal to be initially latched to the cannula at various orientations, and then rotated as needed for use, so that perfect seal orientation alignment is not required for initial latching.

In one aspect, the combination of a cannula, the seal assembly, and an obturator is an assembly. The seal assembly enables the obturator to be coupled to the cannula.FIG.16is a perspective view of a medical device assembly171that includes a cannula172, a seal assembly173latched to cannula172, and obturator174latched to seal assembly173and extending through cannula172and sea assembly173. The top (proximal end) of obturator174is rounded to accommodate the palm of the hand. In use, a surgeon inserts medical device assembly171's distal end through a patient's body wall, and once medical device assembly171is inserted, the surgeon unlatches and withdraws obturator174from seal assembly173and cannula172so that other medical devices, such as an endoscope or a therapeutic surgical instrument, may be inserted through seal assembly173and cannula172to reach a surgical site.

In another aspect, a radially centered hole (not shown) is placed in obturator proximal portion164, and at least the obturator tip161is made transparent. Such a transparent obturator tip is known. An endoscope is inserted through the radially centered hole and through obturator shaft163to obturator tip161. The transparent obturator tip allows the surgeon to view insertion through the body wall. Thus, in one aspect, the combination of a cannula, the seal assembly, the obturator with a clear distal tip, and an endoscope inserted into the obturator is an assembly. The seal assembly enables the obturator to be coupled to the cannula.

As shown, cannula172is configured to be mounted on teleoperated medical device manipulator, part of a teleoperated surgical system, such as systems commercialized by Intuitive Surgical, Inc., Sunnyvale, California. In other implementations, however, medical device assembly171, or any of its components, may be used for non-teleoperated surgical procedures, such as manual laparoscopy procedures.

Teleoperated Medical Device

FIG.17is a perspective view of a cannula175and seal assembly176coupled together and mounted at the distal end of a teleoperated manipulator177, which is part of a teleoperated surgical system. Seal assembly176is representative of the various seal assembly configurations described in this document. It can be seen that seal assembly176's valve176acan rotate clockwise or counter-clockwise within cannula175, as indicated by the double-headed arrow. When several cannula175and seal assembly176are inserted into a patient in close proximity, each combination being docked with a corresponding manipulator177, the ability to orient one or more of the valves176aallows the associated tubing to be more easily coupled to a valve176a, and also to be more effectively routed within the sterile field around the various other cannula entry ports into the patient. Further, the valve orientation can be changed while an instrument is inserted through the seal assembly and the cannula.

FIG.18is a perspective view of an example teleoperated medical device178-ateleoperated surgical system (a portion of the patient-side component of a da Vinci Xi® Surgical System)—that incorporates at least one cannula175and seal assembly176. As shown inFIG.18, an example surgical instrument179is mounted at the distal end of manipulator177, and surgical instrument179's shaft180extends through seal assembly176and cannula175. In some instances, one or more seal assemblies that accommodate one range of instrument shaft sizes (e.g., 5-8 mm) as described are each used with one or more corresponding instrument manipulator, and one or more other seal assemblies that accommodate another range of instrument shaft sizes (e.g., 10-12 mm) as described are used with one or more other corresponding manipulators.

It can be seen, therefore, that a seal assembly is an important component not just generally for minimally invasive surgical applications, but for allowing a teleoperated surgical system to operate effectively. As an example use, a seal assembly and cannula combination is mounted at the distal end of each of teleoperated medical device178's depicted four manipulators, so that various surgical instruments may be inserted through one or more ports in a patient to reach a surgical site. A single seal assembly that accommodates various instrument shaft diameters allows teleoperated medical device178to simultaneously use various instruments with different shaft diameters, and using the same seal configuration for each cannula simplifies operation, because different seal assemblies that are dedicated to use with only one surgical instrument shaft diameter are not necessary. If necessary, therefore, surgical instruments with various diameters may be interchanged between two manipulators without a need for changing the seal assemblies for each cannula.