The present invention relates to a sealing device for trocar, particularly for laparoscopy surgery, permitting introducing surgical instruments with different diameter within the abdomen cavity of the patient in a reliable, versatile, simple, cheap and convenient for the user, including optical devices, ensuring hydraulic sealing around the surgical instrument inserted within trocar.

The present invention further relates to a trocar comprising said sealing device.

It is well known that laparoscopic surgery largely diffused in recent years thanks to its reduced invasiveness.

To carry out an intervention by using laparoscopic technique, it is presently used an invasive surgical device, also known as trocar, usually a disposable sterile device, permitting making a small incision on abdomen walls, through which it is possible inserting within the abdomen cavity all surgical instruments, such as lancet, washing and/or sucking cannula, and optical devices, necessary to make the surgical intervention.

Making reference to figure 1 , it can be observed a trocar comprising a body 5 coupled (usually integral) with a hollow cylindrical cannula 3, the distal end of which is chamfered, i.e. cut according to a plane inclined with respect to a plane orthogonal to the longitudinal axis of said cannula 3. A cap 1 is removably coupled with body 5 and it is provided with a cylindrical obturator ending, at its distal end, with a tip 4 that can pierce tissues and that usually has a chamfer shape. When cap 1 is coupled with body 5, obturator is inserted within cannula 3 from which only the tip 4 projects, so that, when a surgeon grips cap 1 - body 5 assembly, pushing tip 4 against abdomen walls, cutting tissues of the same walls introducing distal portion of the cannula 3 within abdomen cavity. When incision is terminated, cap 1 and obturator are withdrawn to permit introduction of intervention tools through cannula 3, now acting as passage channel, within abdomen cavity. Body 5 is provided with an outer valve 2 for connection of outer insufflation (e.g. for introducing gas) and irrigation apparatuses, always through cannula 3, with abdomen cavity. Body 5 houses inside further valves (not shown in figure 1) ensuring sealing of cannula 3, also when intervention instruments are present.

In order to maintain hydraulic sealing about surgery instrument inserted within trocar, some membranes and sealing devices are known in the art.

Document EP 1348386 describes a reinforced conical membrane comprised of a plurality of layers.

Document EP 1459688 describes a sealing device for trocar comprising two membranes having respective plurality of flexible protective elements, partially juxtaposed each other to realize a conical surface.

Document US 5385552 describes a planar membrane realised by a plurality of planar elements having a semi-circular angular opening partially juxtaposed each other.

Document US 46655752 describes a conical membrane comprised of a single mono-layer conical element.

However, all known trocars have some drawbacks, mainly due to difficulty of efficiently maintaining hydraulic sealing.

Thus, it is the object of the present invention that of permitting in a reliable, versatile, simple, cheap, convenient for the user and safe for the patient way introducing within the abdomen cavity of the patient intervention instruments having variable diameter, including optical devices, ensuring hydraulic sealing around intervention instrument inserted within a trocar.

It is therefore specific object of the present invention a seal device for trocar, comprising a main seal assembly formed by two or more planar seal elements, made of soft elastic material, overlapping each other, characterised in that each planar seal element has a main shaped aperture, having an axis of symmetry, that comprises a first circular area, located in a central area of the planar element, and a second area contained within a half of the planar element and defined by a curvilinear edge, so that around the first circular area soft elastic material is present along an annular sector of more than 180°, each planar seal element having an external edge, whereby said main seal assembly has a through hole formed by the first circular areas of said two or more overlapping planar seal elements and an external edge formed by the an external edges of said two or more overlapping planar seal elements.

Always according to the invention, said curvilinear edge defining said second area includes at least two symmetric convex arcs, whereby at least one chord of each one of said at least two symmetric convex arcs belongs to the soft elastic material.

Still according to the invention, said curvilinear edge defining said second area comprises a concave arc of circumference, preferably subtending an angle not larger than 150°, more preferably not larger than 120°, and two convex semi-circumferences joined to the concave arc and to the circumference of the first circular area, whereby around the first central circular area soft elastic material is present along an annular sector of more than 180° that ends with two semi-circles defined by the convex semi-circumferences which tend to surround the first circular area.

Furthermore, according to the invention, the shaped aperture can be formed by the union of a rectangle or an ellipse, located in a half of the seal element, two ends of which are joined to respective semi-circles.

Always according to the invention each planar seal element can have one or more pairs of additional shaped apertures symmetric to each other with respect to said axis of symmetry of the main shaped aperture, said one or more pairs of additional shaped apertures being contained within the same half of the planar element within which the second area of the main shaped aperture is contained.

Still-according to the invention, the external edge of each planar seal element can be provided with an indicator in correspondence of said axis of symmetry of the main shaped aperture, said main seal assembly being preferably formed by four or five overlapping planar seal elements with the axes of symmetry of the respective main shaped apertures angularly equidistant from one another, each planar seal element being preferably circular or square or hexagonal or octagonal.

Furthermore, according to the invention, seal device can further comprise, in proximal position with respect to said main seal assembly, an input protection assembly formed by two or more planar protection elements, made of a rigid elastic material, overlapping each other, each protection element comprising an external edge defining a central aperture and internally provided with at least one flexible shaped tab orientated towards a centre of the protection element, said at least one flexible tab being spaced apart from said centre of the protection element, whereby said input protection assembly has a through hole formed by the flexible tabs of said two or more overlapping planar protection elements and an external edge formed by the external edges of said two or more overlapping planar protection elements, the external edge of said input protection assembly being integrally coupled to the external edge of said main seal assembly, the external edge of each protection element being preferably shaped as an annulus or as an annular sector, the external edge of each protection element being preferably provided with an indicator in correspondence of an axis of symmetry of the protection element.

Always according to the invention, said at least one flexible tab can comprise an edge defining an arc of circumference subtending an angle lower than 360° around said centre of the protection element, said at least one flexible tab being preferably shaped so as to comprise an annular sector, the ends of which are preferably curvilinear, said input protection assembly being preferably formed by four overlapping planar protection elements with the respective axes of symmetry rotated by 90° with respect to one another.

still according to the invention, said at least one flexible tab can comprise an end orientated towards said centre of the protection element, said end being delimited by a curvilinear edge, preferably comprising a concave arc of circumference, each protection element more preferably comprising either two symmetric flexible tabs, said input protection assembly being still more preferably formed by four overlapping planar protection elements with the respective axes of symmetry rotated by 45° with respect to one another, or four flexible tabs, symmetric in pairs, said input protection assembly being still more preferably formed by two overlapping planar protection elements with the respective axes of symmetry rotated by an angle that is a multiple of 45° with respect to one another.

Further, according to the invention, the flexible tabs of said two or more overlapping planar protection elements can be overlapped each other according to an arrangement wherein a first flexible tab overlaps, in proximal direction, a second flexible tab that is in position closest to the first flexible tab in a direction around said central through hole of said protection assembly selected between a clockwise direction and an anticlockwise direction.

Always according to the invention, the seal device can further comprises a mobile membrane, made of soft elastic material, having a proximal circular rim, that defines a central through hole, which proximal circular rim is externally connected to a cylindrical lateral surface through at least one turn, having a distal apex and a proximal groove, wherein the cylindrical lateral surface extends distally, wherein the distal apex of said at least one turn is capable to be moved radially with respect to the cylindrical lateral surface and the proximal groove is capable to be closed and enlarged with respect to a rest configuration, whereby the proximal circular rim is capable to be moved radially with respect to the cylindrical lateral surface, the proximal circular rim being integrally coupled to the external edge of said main seal assembly.

Still according to the invention said seal device can further comprise a proximal support in proximal position with respect to said input protection assembly and to the mobile membrane, and a distal support in distal position with respect to said main seal assembly and to the mobile membrane, the proximal support centrally defining an aperture and being provided with first coupling mechanical means interacting with second coupling mechanical means with which the external edge of said input protection assembly is provided, with third coupling mechanical means with which the proximal circular rim of the mobile membrane is provided, with fourth coupling mechanical means with which the external edge of said main seal assembly is provided, and with fifth coupling mechanical means with which the distal support is provided, the distal support centrally defining an aperture, the proximal support preferably comprising a proximal circular rim, said first coupling mechanical means preferably comprising a plurality of shaped projections and/or a plurality of pins received in first holes, more preferably in first blind holes, of the distal support, into which the pins are still more preferably pressed and swaged, said second coupling mechanical means preferably comprising at least one, more preferably two, plurality of through holes, said third coupling mechanical means preferably comprising at least one, more preferably two, plurality of through holes, said fourth coupling mechanical means preferably comprising at least one, more preferably two, plurality of through holes.

Furthermore, according to the invention, said seal device can further comprise a distal planar membrane made of soft elastic material, in distal position with respect to the distal support, and a final support, in distal position with respect to the distal planar membrane, the distal planar membrane having a central portion provided with a through hole, an external edge having a thickness larger than the one of the central portion, and a joining intermediate portion having thickness increasing from the one of the central portion to the one of the external edge, the final support centrally defining an aperture and being provided with sixth coupling mechanical means interacting with seventh coupling mechanical means with which the external edge of the distal planar membrane is provided and with eighth coupling mechanical means with which the distal support is provided, said sixth coupling mechanical means preferably comprising a plurality of pins, more preferably received in second holes, more preferably in second blind holes, of the distal support, said seventh coupling mechanical means preferably comprising at least one, more preferably two, plurality of through holes, said eighth coupling mechanical means preferably comprising a plurality of shaped projections received in corresponding holes, more preferably through holes, of the external edge of the distal planar membrane.

Always according to the invention, seal device can be housed in a first and a second annular elements, coupled to each other to form a container of the device and each having a central through hole, the first and second annular elements being provided with ninth coupling mechanical means interacting with tenth coupling mechanical means with which the cylindrical lateral surface of the mobile membrane is provided.

It is also specific object of the present invention a trocar comprising a body, coupled to a hollow cylindrical cannula in which an obturator can be inserted, and a top cap that is capable to be removably coupled to the body, characterised in that the body comprises a seal device as described in the above.

Self-centring seal device for trocar according to the invention permits efficiently maintaining hydraulic seal about one intervention instrument inserted within a trocar.

Further, self-centring device according to the invention permits ensuring hydraulic sealing for a large range of diameters of surgical instruments, preferably variable between 3 and 13 mm.

Still, self-centring device according to the invention can be easily manufactured, with very low manufacturing costs.

The present invention will be now described, for illustrative, but not limitative, purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 shows a schematic side view of a trocar according to the prior art;

figure 2 shows a perspective view (fig. 2a), a front view (fig. 2b), a bottom plant view (fig. 2c), a top plant view (fig. 2d), a section view taken along line AA of figure 2b (fig. 2e), and an enlarged particular of the view of figure 2e (fig. 2f) of a first embodiment of trocar according to the invention;

figure 3 shows a perspective view (fig. 3a), a top plant view (fig. 3b), a bottom plant view (fig. 3c), a section view taken along line AA of figure 3c (fig. 3d), and an perspective view of section according to figure 3d (fig. 3e) of a second embodiment of trocar according to the invention;

figure 4 shows an exploded perspective view of seal device of figure 3;

figure 5 shows a top plant view (fig. 5a), a bottom plant view (fig. 5b), a section view taken along line AA of figure 5b (fig. 5c), and section view taken along line CC of figure 5b (fig. 5d) of proximal support of seal device of figure 3;

figure 6 shows a perspective view (fig. 6a), a top plant view (fig. 6b), a bottom plant view (fig. 6c) of an inlet protection element of seal device of figure 3; figure 7 shows a top plant view (fig. 7a) of an inlet protection element of a second embodiment of the seal device, and a top plan view (fig. 7b) an inlet protection assembly with two inlet protection elements of figure 7a;

figure 8 shows a top plan view of an inlet protection element of a third embodiment of the seal device;

figure 9 shows a perspective view (fig. 9a), a side view (fig. 9b), a top plant view (fig. 9c), an enlarged particular of the view of figure 9c (fig. 9d) a bottom plant view (fig. 9e), a section view taken along line CC of figure 9e (fig. 9f), and an enlarged particular of the view of figure 9f (fig. 9g) of tilting membrane of figure 3;

figure 10 shows a top plant view (fig. 10a), a top plant view (fig. 10b), a bottom plant view (fig. 10c); a side view (fig. 10d) and a schematic plan view comprising forces created under elastic deformation (fig. 10e) of a seal element of seal device of figure 3;

figure 11 shows a perspective view (fig. 11a), a top plant view (fig. 11b), a bottom plant view (fig. 11c), and a side view (fig. 11 d) of seal element of a fourth embodiment of the seal device according to the invention;

figure 12 shows a perspective view (fig. 12a), a top plant view

(fig. 12b), a bottom plant view (fig. 12c), and a side view (fig. 12d) of seal element of a fifth embodiment of the seal device according to the invention;

figure 13 shows a perspective view (fig. 13a), a top plant view (fig. 13b), a bottom plant view (fig. 13c), and a side view (fig. 13d), and a schematic plan view comprising forces created under elastic deformation (fig. 13e) of seal element of a sixth embodiment of the seal device according to the invention;

figure 14 shows a top plant view (fig. 11a) of a seal element of the third embodiment of the seal device according to the invention, and a top plan view (fig. 14b) of a main seal assembly realized with four seal elements of figure 14a;

figure 15 shows a top plant view (fig. 15a) of a seal element of the second embodiment of the seal device according to the invention, and a top plan view (fig. 15b) of a main seal assembly realized with four seal elements of figure 15a;

figure 16 shows a top plant view (fig. 16a), a bottom plant view (fig. 16b), a section view along line AA of figure 16b (fig. 16c), a section view along line BB of figure 16b (fig. 16d) and an enlarged particular of view of figure 16 d (fig. 16e) of distal support of seal device of figure 3;

figure 17 shows a perspective view (fig. 17a), a top plant view (fig. 17b), a side view (fig. 17c), and an enlarged particular of the view of figure 17c (fig. 17e) of distal planar element of seal device of figure 3;

figure 18 shows a top plant view (fig. 18a), a bottom plant view (fig. 18b), a section view along line AA of figure 18b (fig. 18c), and an enlarged particular of view of figure 18c (fig. 18d) of final support of seal device of figure 3;

figure 19 shows a top perspective view (fig. 19a), a bottom perspective view (fig. 19b), a front view (fig. 19c), a rear view (fig. 19d), a first enlarged particular of view of figure 19b (fig. 9e), a second enlarged particular of view of figure 19b (fig. 19f), a top plan view (fig. 19g), a bottom plan view (fig. 19h), and a section view taken along line AA of figure 19h of the first annular element of seal device of figure 3;

figure 20 shows a bottom perspective view (fig. 20a), a top perspective view (fig. 20b), a bottom plan view (fig. 20c), a side view (fig. 20d), a rear view (fig. 20e), a front view (fig. 20f), a top plan view (fig. 20g), and a section view taken along line AA of figure 20h, a first enlarged particular of view of figure 20h (fig. 20i), a second enlarged particular of view of figure 20h (fig. 20j) of the second annular element of seal device of figure 3; figure 21 shows an exploded perspective view of the second embodiment of the seal device according to the invention; and

figure 22 shows an exploded perspective view of the third embodiment of the seal device according to the invention.

In the figures, the same reference numbers will used for similar elements.

Particularly, quotations shown in the figures (in mm, unless indicted differently) are an example and must not be interpreted as limitative of the scope of the present invention, unless clearly indicated the contrary.

Specific reference will be made in the following to particular embodiments of trocar according to the invention comprising a specific bladeless obturator with a helicoidally shaped tip, a cp the top of which is specifically shaped, and a body having a specific structure. It must in any case taken into consideration that trocar according to the invention can provide every type of obturator, even with blades and a tip having a shape different with respect to the helicoidal shape shown in the figures (e.g. chamfer), a cap with every other shape, a differently structured body, always remaining within the scope of the present invention.

Furthermore, reference is made in the present specification and claims to soft elastic materials and to rigid elastic materials, being thus meant that soft elastic materials have yield strength or yield point higher than that of rigid elastic materials.

Making reference to figure 2, it can be observed a first embodiment of trocar according to the invention, comprising a cap 10, removably coupled (by specific mechanical means 11) with a body 13, the upper portion of which (to which cap 10 is coupled) comprises a first embodiment of seal device 24 according to the invention. Specific features of cup 10 and mechanical means by which it is removably coupled to body 13 are not part of the scope of the present invention and are not essential. Upper portion of body 13 comprises a first annular element 14 coupled with- a second annular element 15, so that first and second annular elements 14 and 15, when assembled each other, act as housing of the seal device 24.

Lower portion of body 13 comprises a container 26 housing proximal end of a hollow cylindrical cannula 29. Proximal end of cannula 29 is provided with a front inlet/outlet conduct 30 provided with a tap 31 controlled by a corresponding valve 32, to permit coupling from inside cannula 29, e.g. with outer insufflations apparatuses (e.g. to introduce gas). A lip seal valve 33 is housed in proximal end of cannula 29. Outer wall of cannula 29 is preferably centrally provided with an anti-slippery working comprised of rings 36 having a preferably triangular section. A bladeless obturator 23 is suitable to be introduced within cannula 29, having a helicoidal tip.

Particularly, when obturator 23 is inserted within cannula 29, or at least a surgical instrument is inserted within abdominal cavity of patient by trocar, it is device 24 that ensures seal of abdomen cavity (preventing outflow of biological fluids, usually maintaining pressure difference with respect to outside). When instead neither obturator 23 is inserted within cannula 29 nor any other surgical instrument is inserted within abdomen cavity, it is lip valve 23 that ensures seal of abdomen cavity.

Specific features of container 28, cannula 29 and tap 31 , of lip seal valve 33, and of obturator 23 are not part of the scope of the present invention, and are not essential for the same.

Figures 3 and 4 show seal device 24 housed within first and second annular elements 14 and 15, acting as proximal and distal closure, respectively, of the same device 24, said device comprising:

- a proximal circular corona 41 , acting as proximal support (or inlet support);

- four inlet protection elements 42; - a tilting membrane 43;

- four seal elements 44;

- a spacer 45 acting as distal support;

- a distal annular membrane 46; and

- a distal circular corona 47 acting as final support (or outlet support).

As shown in figure 5, proximal circular corona 41 is provided with eight pegs 410 on its distal surface, angularly equidistant each other, and with three shaped projections 411 , 412, 413, angularly positioned at the centre of respective pairs of pegs 410; one of the three projections, indicated in figure 5 by reference number 41 1 , has a base shape different with respect to the shape of the other two projections (indicated by reference numbers 412 and 413); height of pegs 410 is higher than height of shaped projections 41 1 , 412, 413, and three projections 41 1 , 412, 413 are angularly provided at the centre of respective pairs of pegs 410. Proximal circular corona 41 is comprised of a rigid material, preferably plastic material, more preferably polycarbonate.

Other embodiments of the seal device according to the invention can provide that proximal circular corona 41 has a different number of pegs and/or a different number of shaped projections and/or different shapes of the same projections, and/or only pegs without the shaped projections (or vice versa).

Making reference to figure 6, it can be observed that each one of four inlet protection elements 42 is a planar element comprised of rigid plastic material (in figure 6 with a thickness of about 0.2 mm, although this is not an essential feature), shaped as a circular corona 420, provided inside with a flexible tab 421 , geometrically realised by a sector of circular corona of 180°, the centre of which is centre of protection element 42, the ends of which 422 are connected with two hemi-circumferences; inner flexible tab 421 is connected to circular corona 420 by a connection portion 423 having such an amplitude that can be compared (in the figure it is slightly larger) with width (i.e. difference of rays) of the circular corona sector 420. Circular corona 420 is provided with two pluralities of through holes: a first plurality of eight circular through holes 424, equiangular spaced each other, suitable to receive pegs 410 of proximal circular corona 41 , and a second plurality of eight through holes 425, so shaped to receive shaped projections 411 , 412 and 413 of proximal circular corona 41. Circular corona 420 is further provided outside, in correspondence of symmetry axis of inner flexible tab 421 , of an indicator 426 useful to orient inlet protection element 42. Rigid elastic material of four inlet protection elements 42 is preferably a plastic material, more preferably a thermoplastic elastomer such as polyurethane or Hytrel, available from DuPont, and/or polycarbonate. As shown in figure 3b, stably juxtaposing (by pegs 410 and shaped projections 411 , 412, 413 of proximal circular corona 41 ) four inlet protection elements 42 so that they are rotated of 90° each other (thanks to indicators 426), an inlet protection assembly is realised having a central through hole, diameter of which increases when it is subjected to a (small) pressure exerted by a surgical instrument on its proximal surface thanks to the consequent elastic flexion along a distal direction of tabs 421. Assembly of four inlet protection elements 42 protects tilting membrane 43, four seal elements 44, and distal annular membrane 46, comprised of soft elastic materials with respect to surgical instruments.

Other embodiments of the seal device according to the invention can provide that portion 423 connecting flexible tab 421 and circular corona 420 has a different dimension, preferably depending on material elasticity, and/or that inlet protection elements 42 have, instead of a circular corona 420, an edge shaped as a sector of circular corona, to which flexible tab 421 is connected, and/or that shape of ends 422 of flexible tab 421 , and/or shape of ends 422 of flexible tab 421 is different with respect to a hemi-circumference (and preferably curvilinear, to prevent abrasions on components comprised of soft elastic materials) and/or that angular width of corona circular sector of inner flexible tab 421 is lower than 180° (and in this case it could be necessary a number of elements 42 higher than four) or bigger than 180° (being in any case lower than 360°, i.e. maintaining an open sector of circular corona and not a closed circular corona) provided that elasticity deriving from shape and material of flexible tab 421 in any case permits an efficient flexion to permit introduction of a surgical instrument (and in this case it could be sufficient a number of elements 42 lower than four), and/or that number of elements is different from four, as well as flexible tab 421 is differently shaped in correspondence of a central area of element 42. Other embodiments of seal device according to the invention can also provide that inlet protection elements 42 have not circular outer edges, said edges having different shapes, e.g. (at least partially) the shape of a regular polygon (e.g. square, hexagonal or octagonal), or even an irregular shape.

For example, making reference to figure 7a, it can be observed a protection element 42B of a second embodiment of seal device according to the invention, which is different with respect to the one shown in figure 6 since it has not four flexible tabs 421 B, which are symmetrical at pair, connected to the circular corona 420 by relevant connection portions 423, each one of the flexible tabs 421 B comprising an end 422 B oriented toward centre of protection element 42B. Particularly, end 422 B is limited by a concave circumference arc (by "concave" it is meant that a cord of the circumference arc is of the flexible tab 421 B); generally speaking, other embodiments of the seal device according to the invention can provide that said end 422B faced toward centre of protection element 42B is defined by every circular concave and/or convex curvilinear edge. In this case too, circular corona 420 is further provided outside, in correspondence of a symmetry axis of protection element 42B, of an indicator 426 useful to orient inlet protection element 42B. As shown in figure 7b, inlet protection assembly with a central through hole is realised stably juxtaposing two inlet protection elements 42B, so that they are rotated each other of an angle which is a multiple of 45° (thanks to indicators 426). Particularly, as shown in figure 7b, it is advantageous juxtaposing each other flexible tabs 421 B of two inlet protection elements 42B according to an arrangement wherein a flexible tab 421 B of a protection element 42B is juxtaposed (according to a proximal direction, i.e. considering a line exiting from the sheet oriented according to a proximal direction) to flexible tab 421 B (of the other protection element 42B) which is in a closer position according to a clockwise direction (about the central through hole of the inlet protection assembly - obviously the same result is obtained in case juxtaposition is carried out along an anti-clockwise direction).

Still as an example, making reference to figure 8, it can be observed a protection element 42C of a third embodiment of the seal device according to the invention differing from the one shown in figure 6 since it is provided with two symmetric flexible tabs 421 C, connected with circular corona 420 by relevant connection portions 423, each one of said flexible tabs 421 C comprising an end 422C oriented toward centre of protection element 42C. Particularly, end 422C is defined by a concave circumference arc (by "concave" it is meant that a cord of circumference arc belongs to the flexible tab 421 C); generally speaking, other embodiments of the seal device according to the invention can provide that said end 422C faced toward centre of protection element 42C is defined by any concave and/or convex curvilinear edge. In this case too, circular corona 420 is provided outside, in correspondence of a symmetry axis of protection element 42C, with an indicator 426, useful for orienteering inlet protection element 42C. Inlet protection assembly with a central through hole is in this case realised stably juxtaposing four inlet protection elements 42C, so that they are rotated of 45° each other (thanks to indicators 426). Similarly to what is shown in figure 7b, it is advantageous- juxtaposing each other flexible tabs 421 C of four inlet protection elements 42C according to an arrangement wherein a flexible tab 421 C of a protection element 42C is juxtaposed (along a proximal direction, i.e. taking into consideration a line coming out the sheet and oriented according to a proximal direction) to the flexible tab (of another protection element 42C) which is in a closer position according to a clockwise direction (about the central through hole of the inlet protection assembly - obviously the result is identical in case juxtaposition is carried out according to anti-clockwise direction).

Making reference to figure 9, it can be observed that tilting membrane 43 has a shape including a proximal circular corona 430 connected to a cylindrical lateral surface 431 by a coil having a substantially triangular section with a distal apex 432 (realising a proximal throat 433), wherein lateral cylindrical surface 431 extends according to a distal direction ending with an outer circular corona 434, provided outside with an edge 435 projecting along a distal direction. Proximal circular corona 430 is provided with eight holes 436 and with their shaped holes 437A, 437B, 437C, one of which (indicated by reference number 437A in figure 9), has a base shape different with respect to the other two projections (indicated in figure 9 by reference numbers 437B and 437C). Eight holes 436 are angularly and radially positioned as eight pegs 410 of proximal circular corona 41 , and holes 436 are so shaped in such a way to be suitable to receive pegs 410; in the same way, three shaped holes 437A, 437B and 437C are angularly and radially positioned as three shaped projections 411 , 412, 413 of proximal circular corona, respectively. Outer circular corona 434 is stably coupled with annular elements 14 and 15, also thanks to the projecting edge 435; furthermore, outer circular corona 434 is outside provided with a projection 438 according to a proximal direction permitting proper positioning of tilting membrane 43 between annular elements 14 and 15. Particularly, the way of coupling of outer circular corona 434 with annular elements 14 and 15 is shown in figure 3d and will be described in further detail in the following. Tilting membrane 43 is comprised of soft elastic material, preferably an elastomer, more preferably an isoprene rubber (IR), still more preferably with a Shore A hardness of 35. Tilting membrane 43 can, radially displacing distal apex 432 of coil (i.e. closing and enlarging throat 433 and at the same time approaching and moving away, respectively, distal apex 432 from/toward cylindrical lateral surface 431), to radially displace all seal device 24 with respect to annular elements 14 and 15 within which it is contained, thus permitting a radial displacement of a surgical instrument introduced within trocar with respect to longitudinal axis of container realised by the same annular elements 14 and 15, and thus also a better possibility of introduction of surgical instruments within patient abdomen cavity by trocar with different angulations with respect to cannula 29 longitudinal axis. As shown in figure 21 , coupling of outer circular corona 434 with annular elements 14 and 15 concurring to ensure seal of device 24, preventing leakages due to lateral passages to central hole 439 of tilting membrane 43 and to the main seal element.

Other embodiments of the seal device according to the invention can provide that tilting membrane 43 has a number of coils higher than one, and/or one or more coils having a not triangular section, and/or elastic means deformable along radial direction at least partially different with respect to coil and cylindrical lateral surface 431 to permit a radial displacement of seal device with respect to trocar longitudinal axis, and/or that tilting membrane 43 is provided with coupling means with container of seal device (comprised of annular elements 14 and 15) at least partially different with respect to outer circular corona 434, projecting edge 435 and projection 438, and/or that proximal circular corona 430 has a number of circular holes 436 higher than the number of pegs 410 of the support proximal circular corona 41 , and/or that proximal circular 430 has a number of shaped holes higher than that of shaped projections of the support proximal circular corona 41.

Making reference to figure 10, each one of the four seal elements 44 is a shaped circular disc comprised of soft elastic material (preferably having a thickness between 0.15 mm and 0.20 mm, although this is not an essential feature). Circular disc is so shaped to have a shaped opening 440 comprising a first central circular area 441 (preferably having a diameter lower than the diameter of the central through hole created by the assembly of the four inlet protection elements 42, as shown in figure 3b) connected with a second area within a half of the circular disc and defined by a concave circumference arc 442 of about 150° and two convex circumferences (by "convex" it is meant that at least a cord of the two circumferences belongs to the soft elastic material) joined to the concave arc 442 and to circumference of the first central circular area 441 ; thus, soft elastic material is present around the first central circular area

441 for a circular corona sector of more than 180" ending with two hemi- circumferences (defined by convex hemi-circumferences 443) tending to wound the first central circular area 441. Outer edge of the shaped circular disc, including the circular corona sector 444 defined by the concave arc

442 of the shaped opening 440, is provided with two pluralities of through holes; a first plurality of eight circular through holes 445, equiangular spaced each other, suitable to receive pegs 410 of proximal circular corona 41 ; and a second plurality of eight through holes 446, so shaped to receive shaped projections 411 , 412 and 413 of proximal circular corona 41. Shaped circular disc is further provided outside, in correspondence of a symmetry axis of the second area of the shaped opening 440), of an indicator 447 useful to orient the seal element 44. Soft elastic material of the four seal elements 44 is preferably an elastomer, more preferably an isoprene rubber (IR), still more preferably with a Shore A hardness of 35. As shown in figure 3b, stably juxtaposing (by pegs 410 and shaped projections 411 , 412, 413 of proximal circular corona 41) four seal elements 44 so that they are rotated of 90° each other (thanks to indicators 447), a main seal assembly is realised having a central through hole comprised of the central circular areas 441 of the four seal elements 44. Diameter of said central through hole increases when it is subjected to a (little) pressure exerted by a surgical instrument on its proximal surface thanks to consequent elastic deformation; to this end, diameter of the central through hole is smaller than the smallest diameter of a surgical instrument that can be introduced. Particularly efficient adherence between seal elements 44 and surgical instrument ensures hydraulic sealing even in presence of a relevant pressure difference between trocar portion upward and downward the seal device 24. As shown in figure 10e, adhesion is particularly efficient thanks to the shaped circular disc starting from central circular area 441 up to the outer edge (comprising the circular corona sector 444), i.e. in correspondence of diameters of hemi- circumferences 443, two elastic cords; along said two elastic cords two respective forces F1 and F2 are created when the seal element 44 is deformed by introducing a surgical instrument, the resultant force R of which is opposed by constraint of the surgical instrument, thus producing an adhesion pressure B of seal element 44 on surgical element (along an arc of at least 120°, and higher with a lower elastic deformation of the same seal element 44). Since main seal assembly is comprised of four seal elements 44, juxtaposed and rotated each other, said adhesion pressure is concretely exerted on all circumference of the surgical instrument, thus preventing rolling according to the proximal direction of the four seal elements 44 when the surgical instrument (or obturator 23) is withdrawn from cannula 29.

Other embodiments of the seal device according to the invention can provide that seal elements 44 have an opening with a different shape with respect to those shown in figure 1 , provided that it has a first central circular area 441 , partially surrounded for more than 180° by soft elastic material and a second area within a half of the circular disc and defined by a curvilinear edge comprising at least two convex symmetric arcs joined to the central circular area 441 (again, by "convex" it is meant that at least a cord of each one of said at least two symmetric arcs belongs to the soft elastic material), so that at least a pair of elastic cords is present in soft elastic material starting from the central circular area 441 up to the outer edge of the seal element, and/or can provide presence of one or more pairs of additional symmetric openings, contained within the same half of the circular disc wherein second area of the main shaped opening is contained, and provided symmetrically with respect to the symmetry axis of the second area of the main shaped opening (and thus with respect to the symmetry axis of the main shaped opening) to realize pairs of additional elastic cords, and/or can also provide that number of seal elements 44 is different with respect to four.

To this end, figure 1 1 shows a seal element 44B according to a fourth embodiment of the seal device according to the invention, wherein shaped opening 440B is different with respect to the one shown in figure 10 in that first central circular area 441 B has a diameter slightly lower than, and consequently diameters of two hemi-circumferences 443B are slightly higher, thus causing a higher adhesion pressure of seal element 44B on surgical instrument than pressure induced by element 44 of figure 10.

Figure 12 shows a seal element 44C according to a fifth embodiment of the seal device according to the invention wherein shaped opening 440C is different with respect to the one shown in figure 10 in that circumference arc 442C has an lower extension, thus causing a higher adhesion pressure of seal element 44C on surgical instrument than pressure induced by element 44 of figure 10.

Figure 13 shows a seal element 44D according to a sixth embodiment of the seal device according to the invention wherein shaped opening 440D is much more less extended with respect to the one of element 44 shown in figure 10, although it includes the same first central circular area 441 , and wherein a pair of additional symmetric openings 448 is present, contained within the same half of the circular disc wherein second area of shaped opening 440D is contained. As shown if figure 13e, the above creates a pair of additional elastic cords along which two respective additional forces F3 and F4 (stably oriented by definition of relevant additional cords between shaped opening 440D and a relevant additional opening 448), are created when seal element 44D is deformed while introducing a surgical instrument, thus increasing value of resulting force R, and consequently a higher adhesion pressure caused by seal element 44 on surgical instrument than pressure induced by element 44 of figure 10.

Figure 14a shows a seal element of the third embodiment of seal device according to the invention wherein shaped opening 440E is comprised of coupling of a radial rectangle, positioned in a half of the seal element 44E, the long sides of which are parallel to a ray of seal element 44E comprising a symmetry axis of the shaped opening 440E, and the short sides of which are joined to two hemi-circumferences. Also in this case, shaped opening 440E provides a first central circular area, so that main seal assembly (shown in figure 14b) obtained juxtaposing a plurality, preferably four, seal elements 44E, has a through hole realized by the first circular areas of said plurality of juxtaposed seal elements 44E (diameter of said central through hole is still lower than the smallest diameter of a surgical instrument to be introduced there through). Although shaped opening 440E does not include a second area defined by a curvilinear body providing at least two convex symmetrical arcs of soft elastic material, however, since material by which seal elements 44E are comprised is a soft elastic material, preferably an elastomer, when a surgical instrument is inserted though said central through hole, centripetal forces F create around the hole, as shown by arrows of figure 14b, thus causing adhesion of the main seal assembly around surgical instrument, thus ensuring hydraulic seal.

Figure 15 a shows a seal element 44F according to the second embodiment of seal device according to the invention wherein shaped opening 440F is comprised of a radial ellipse, positioned in a half of the seal element 44F, the main axis of which is positioned along a ray of seal element 44F comprising a symmetry axis of the shaped opening 440F, and the ends of which are joined to circular areas. Also in this case, shaped opening 440F provides a first central circular area, so that main seal assembly (shown in figure 15b) obtained juxtaposing a plurality, preferably four, seal elements 44F, has a through hole realized by the first circular areas of said plurality of juxtaposed seal elements 44F (diameter of said central through hole is still lower than the smallest diameter of a surgical instrument to be introduced there through). Also in this case, although shaped opening 440F does not include a second area defined by a curvilinear body providing at least two convex symmetrical arcs, and thus cords of said convex symmetric arcs of soft elastic material do not exist, however, since material by which seal elements 44F are comprised is a soft elastic material, preferably an elastomer, when a surgical instrument is inserted though said central through hole, centripetal forces F create around the hole, as shown by arrows of figure 15b, thus causing adhesion of the main seal assembly around surgical instrument, thus ensuring hydraulic seal.

Other embodiments of the seal device according to the invention can also provide that seal elements 44 are not circular discs, but rather different planar elements, e.g. having the shape of a regular polygon (e.g. square, hexagonal or octagonal shape), or even irregular, and with a central area and an outer edge. As shown if figure 16, spacer 45 has a cylindrical lateral surface 450 and an inner surface with a frusto-conical proximal surface 451 , the diameter of which decreases from proximal end according to a distal direction, and a tapered distal portion 452, with a lower height with respect to the proximal portion, and the diameter of which decreases from proximal end according to a distal direction up to joining with frusto-conical proximal portion 451. Proximal surface 453 has the shape of circular corona (as shown in plain view of figure 16a), on which two concentric circular ribs 454 are provided (that can be better observed in figure 16a), increasing adhesion of distal surface of outer edge of seal element 44 adjacent to spacer 45. Proximal surface 453 is provided with eight blind holes 454, with a hexagonal base, angularly equi-spaced each other, suitable to receive pegs 410 of proximal circular corona 41 . Distal surface 456 ha a circular corona shape as well (as shown form plan view of figure 16b) on which three circular concentric ribs 457 are provided (that can be better observed in figure 16e), increasing adhesion of outer edge proximal surface of distal annular membrane to spacer 45. Distal surface 456 is provided with eight blind holes 458, with a hexagonal base, angularly equi- spaced each other, each one of them being angularly equidistant with respect to a pair of blind holes 458 adjacent to the same distal surface 456; particularly, height of shaped projections 459 is much lower than depth of blind holes 458. Spacer 45 is comprised of rigid material, preferably of plastic material, more preferably of polycarbonate.

Other embodiments of the seal device according to the invention can also provide that spacer 45 has a different shape of inner surface and/or a different number of blind holes and/or different shape of the same blind holes and/or a different number of shaped projections and/or different shapes of the same projections, and/or that they have only blind holes but not shaped projections (or vice versa).

As shown in figure 17, distal annular membrane 46 has the shape of a disc provided with a through central hole 460 and having a central portion 461 , an outer edge 462 much more thick than the central portion 461 , and a junction intermediate portion 463 with a thickness increasing from the central portion 461 to the outer edge 462. Outer edge 462 is provided with eight circular through holes 464, angularly and radially provided as they are the eight blind holes 458 of distal surface 456 of spacer 45. Furthermore, outer edge 462 is provided with four shaped holes 465 angularly and radially positioned as four shaped projections 459 of the distal surface 456 of spacer 45; particularly, four holes 465 are so shaped to be suitable to receive four shaped projections 459 of distal surface 456 of spacer 45. Distal annular membrane 46 is comprised of soft elastic material, preferably an elastomer, more preferably of isoprene rubber (IR), even more preferably with a Shore A hardness of 35. Distal annular membrane 46 acts as additional seal membrane for surgical instrument with large diameter, preferably higher than about 7 mm. Discontinuity of thickness between central portion 461 and outer edge 462 permits obtaining an efficient compromise between a high elasticity, by central portion 461 promoting penetration of surgical instrument thus ensuring adhesion of central portion 461 to surgical instrument, and necessary strength necessary to integrity of the same distal annular membrane 46, by its outer edge 452.

Other embodiments of the seal device according to the invention can also provide that distal membrane has a uniform thickness, and/or a different shape but the annular one and/or different shape of the through holes. Further embodiments of the seal device according to the invention can be not provided with distal annular membrane.

As shown in figure 18, distal circular corona 47 is provided on its proximal surface 470 with eight pegs 471 , angularly and radially provided as they are the eight through holes 464 of the distal annular membrane 46 and eight blind holes 458 of distal surface 456 of spacer 45, so that through holes 464 of distal annular membrane 46 and blind holes 458 of spacer 45 are suitable to receive pegs 471. Two concentric circular ribs 472 are present on proximal surface 470, increasing adhesion of distal surface of outer edge 462 of annular distal membrane 46 on distal circular corona 47. Distal circular corona 47 is comprised of rigid material, preferably of plastic material, more preferably polycarbonate.

Other embodiments of the seal device according to the invention can provide that distal circular corona 47 has different number of pegs. Embodiments of the seal device according to the invention not provided with distal annular membrane 46 are neither provided with distal circular corona 47, and in this case distal surface 456 of spacer 45 cannot be provided with ribs 457 and/or blind holes 456 and/or shaped projections 459.

When seal device 24 is assembled (as shown in figure 3), pegs 410 of proximal circular corona 41 and pegs 471 of distal circular corona 47 are preferably pressed within blind holes 455 and blind holes 458, respectively, of spacer 45 and hot retorted. Particularly, shaped projections 412 of proximal circular corona 41 and shaped projections 459 of spacer 45 have such heights not to hinder assembling of seal device.

Making reference to figure 19, it can be observed that first annular element 14, acting as proximal closure of seal device 24, comprises a central hole 140 and two through holes 141 , interacting with mechanical means 1 1 (e.g. two corresponding pins that can be elastically displaced) in order to permit coupling and removal of cap 10 to which obturator 23 is fixed. Specific modes of mechanical interaction of first annular element 14 with mechanical means 1 1 , and thus with through holes 141 , are not part of the scope of the present invention and they are not essential to the same.

Lateral surface 143 of first annular element 14 has a cylindrical shape and provides a cylindrical projecting distal edge 142 having a diameter lower than that of the lateral surface 143. Distal edge 142 is provided with a narrow cavity 144 (shown in detail in figure 19e), with which an indicator 145, provided on lateral surface 143m is aligned. A wide cavity 146 (shown in detail in figure 19f) is provided on lateral surface 143, in a position diametrically opposed with respect to indicator 145.

Making reference to figure 20, it can be observed that second annular element 15, acting as distal closure of seal device 34, comprises a central through hole 150, about which a shaped mechanical actuator 5 is provided, with two teeth 152 and 153, diametrically opposed each other, interacting with corresponding mechanical means on trocar body 13 to permit coupling and removal of container (comprised of first and second annular element 14 and 15, when assembled) of seal device 24. Shaped mechanical actuator 151 , two teeth 152 and 153, corresponding mechanical means of body 13 and specific mechanical interaction modes are not part of the scope of the present invention and they are not essential to the same.

Lateral surface of second annular element 15 is substantially cylindrical and provides an outer portion 154, provided with a cylindrical projecting distal edge 155 with a diameter lower than that of the outer portion 154, and an inner portion 156; outer 154 and inner 156 portions define a cylindrical cavity 157. Outer portion 154 is provided with a projecting tooth 158 (shown in detail in figure 20), suitable to enter within wide cavity 146 of lateral surface 143 of first annular element 14, and, in a diametrically opposed position with respect to the projecting tooth 158, with an indicator 159, suitable to align with indicator 145 of lateral surface 143 of first annular element 14. Annular elements 14, 15 are comprised of rigid material, preferably a plastic material, more preferably polycarbonate. Preferably, when assembled, annular elements 14, 15 are glued each other.

As shown in figure 3d, when seal device 24 is assembled within annular elements 14, 15, projecting edge 435 of tilting membrane 43 is housed within cylindrical cavity 157 defined by outer 154 and inner 156 portions of lateral surface of second annular element 15, while outer circular corona 434 of tilting membrane 43 is maintained between cylindrical distal edge 142 of first annular element 14 and inner portion 156 of second annular element 15. Projection 438 of tilting membrane 43 is housed within narrow cavity 144 of distal edge 142 of first annular element 14. Thus, tilting membrane 43 seals seal devices 24 aside main seal assembly comprised of the four seal elements 44.

Specific components for mechanical coupling between first annular element 14, second annular element 15 and tilting membrane 43 are not essential to the invention, and other embodiments of the seal device according to the invention can provide different components.

Other embodiments of the seal device according to the invention can comprise components analogous to those shown in figures 3 and 4, possibly without distal annular membrane 46, provided according to a different arrangement with respect to the one shown in figure 3.

For example, figure 21 shows the second embodiment of the seal device according to the invention, housed within first and second annular elements 14, 15, acting as proximal and distal closure, respectively, of the same device, said device comprising, according to the following order:

- proximal circular corona 41 , working as proximal support (or inlet support);

- to inlet protection elements 42B, as those shown in figure 7a;

- four seal elements 44F, as the one shown in figure 15a;

- spacer 45, acting as distal support;

- tilting membrane 43; and

- distal circular corona 47, acting as final support (or exit support).

Still as an example, figure 22 shows the third embodiment of the seal device according to the invention, housed within first and second annular elements 14, 15, acting as proximal and distal closure, respectively, of the same device, said device comprising, according to the following order:

- proximal circular corona 41 , working as proximal support (or inlet support);

- four inlet protection elements 42C, as the one shown in figure 8;

- five seal elements 44E as those shown in figure 14a;

- spacer 45, acting as distal support;

- tilting membrane 43; and

- distal circular corona 47, acting as final support (or exit support).

Preferred embodiment of the present invention have been described in the above, and variations of the same invention have been suggested, but it is to be understood that those skilled din the art can introduce modifications and variations to the same without departing from the relevant scope, as defined in the enclosed claims.