This invention relates to a surgical tool and in particular to a self-sealing surgical tool.
Generally, a cannula is a tube that can be inserted into the body, often for the delivery or removal of fluid. In medical applications, a cannula can surround the inner or outer surfaces of a Trocar needle, for example, which is passed through the cannula, puncturing the body in order to get into an intended proximate position.
During certain medical procedures, a surgeon may typically use several hand pieces or instruments that are subsequently inserted into and removed from the cannula. This repeated removal and insertion can cause trauma during an ophthalmic procedure, for example. To address this concern, hubbed cannula were developed at least by the mid-1980s. These devices consist of a narrow tube with an attached hub. For example, in an ophthalmic medical procedure, the tube is inserted into an incision in the eye up to its hub, which acts as a stop, preventing the tube from entering the eye completely. Surgical instruments can then be inserted into the eye through the tube, and the tube protects the incision sidewall from repeated contact by the instruments.
The loss of intraocular pressure during an ophthalmic medical procedure is a concern when instruments are exchange or removed through a cannula. The eye, being a pressurized globe, expels aqueous or vitreous out of the open cannula when a surgical device is not present. As a result, seals have been introduced into cannula designs, which self seal upon instrument removal. These cannula, an example of which is shown in US Patent Application Publication Number 2008/0312662, generally consist of a tube and an attached hub, with a sealing disc positioned in an opening that is recessed from a top surface of the hub.
In order to secure the seal in the hub of the cannula, a separate cap is positioned on top of the hub, covering the top surface and the seal positioned in the opening.
There are several disadvantages with these known cannula, which include, inter alia, higher demand in manufacturing the known cannula, which includes several separate pieces notwithstanding the seal. Furthermore, the known cap is a separate piece that sits on top and around the cannula hub, which is not secured to the cannula hub. As a result, the cap and seal maybe become loose during the procedure.
Other cannula arrangements have further disadvantages. The company, DORC has fits a kind of cap over a flange on the hub of the cannula, which cap provides a seal between the instrument and trocar. However, such a cap has the disadvantage of increasing the external diameter of the trocar. Additionally, this method of sealing between the instrument and trocar leaks and is inadequate. The described invention by this application provides a superior sealing arrangement by virtue of the hinge method used to affect the seal.
U.S. Pat. No. 5,865,807 describes a further seal that can be arranged inside a trocar. This seal has two sealing locations. This is advantageous regarding the quality of the seal but disadvantageous in that the instruments have to be pushed longitudinally along the two seals increasing the force necessary to maneuver with in the eye.
The present invention improves upon known surgical tool that is self sealing. The self sealing surgical tool is a cannula that includes a body and a sealing disc. The body includes a tube positioned at a distal end and a hub at a proximal end. Furthermore, the body includes a sealing disc receiving space positioned through a sidewall of the hub. The sealing disc is securable within the sealing disc receiving space.
The invention will now be described by way of example with reference to the accompanying figures of which:
The invention will now be described in greater detail first with reference to
With respect to
The body 10 has a tube 12 at a distal end, and a hub 14 at a proximal end. The hub 14 is positioned on top of the tube 12, and includes a sealing disc receiving space 30 passing through a portion of a sidewall of the hub 14. The hub 14 and sealing disc receiving space 30 are designed such that the sealing disc 50 may be fittingly secured within the hub 14, which will be discussed in more detail below.
The body 10 may be made from any material suitable for medical procedures, such as stainless steel, titanium, or thermoplastic, while the sealing disc 50 may be made form an elastically deformable material, such as a thermoplastic.
The tube 12 is a hollow, elongated structure, extending from a bottom surface of the hub 14. The tube 12 has a narrow external tubular wall which tapers toward a distal end of the cannula 1. The tube 12 is wide enough such that medical instruments can enter and extend through the tube 12.
The hub 14 is wider than the tube 12, and has a cylindrical shape in the embodiment shown. The hub 14 has an opening 40 formed along a top surface of the hub 14. The opening 40 extends through the hub 14 and into tube 12. The opening 40 and the tube 12 are aligned, such that a medical instrument can enter into the opening 40 and extend through the hollow tube 12.
The hub 14 is a monolithic structure having a cover 16 and a base 18, which are connected together by a bridge 20. The sealing disc receiving space 30 is provided between the base 18 and the cover 16, and closed at one end by the bridge 20. It also possible that the sealing disc receiving space 30 is closed along multiple sidewalls limiting the openings available for ingress and egress of the sealing disc 50. In the shown embodiment, the hub 14 is cylindrical; however, other polygonal shapes are possible, which may include multiple sidewalls.
The cover 16 is generally the top section of the hub 14, while the base 18 is the bottom section of the hub 14. The bridge 20 is provided when the sealing disc receiving space 30 is formed. In the embodiment shown, the sealing disc receiving space 30 is formed in the hub 14 by cutting out a proximate middle section of the hub 14 from a single side. As shown in the
Since the bridge 20 connects the cover 16 and the base 18, the bridge 20 provides structural integrity to the cover 16 and base 18, It should be understood that the bridge 20 is not limited to the shape or size shown in this embodiment, and is intended to support the cover 16 in such a way that the cover 16 is not damaged by external forces. Furthermore, the bridge 20 is a wall and guide for an incoming sealing disc 50, being positioned in the sealing disc receiving space 30. The bridge 20 includes a key 22 which is a flat surface in the embodiment shown. This key 22 cooperates with the sealing disc 50 to facilitate it's alignment within the sealing disc receiving space 30 in an operating position. Although the key 22 is flat in the embodiment shown, the key 22 could include any number of teeth or shapes that would match corresponding teeth and shapes on a receiving sealing disc 50. In fact, the key 22 can be angled, as well. An outer edge of the key 22 may extend slightly back toward the bridge 20 and the base 18, such that the angled key 22, when matched with a corresponding angled disc key 54, provides further alignment and securing of the sealing disc 50 within the hub 14. Depending on the material properties, the bridge 20 may be elastically deformable, and can deform in such a way that the cover 16 can rotate away from the base 18, or toward the base 18, as to close a sealing disc 50 within the sealing disc receiving space 30.
The opening 40 includes an external receiving passageway 42 provided through the cover 16 and an internal receiving passageway 44 through the base 18 of the hub 14 (see
With reference to
The slit 52 is positioned at a proximate middle of the sealing disc 50, which is in alignment with the opening 40, external receiving passageway 42, internal receiving passageway 44, and opening of the hollow tube 12. The slit 52 extends through the thickness of sealing disc 50, and is angled between about 40-50 degrees (most preferably 45 degrees), but it should be understood that other angles are within the scope and spirit of the invention and so the angle may be varied depending upon the requirements of a particular application.
Referring to
With reference to
The body 110 has a tube 112 at a distal end, and a hub 114 at a proximal end. The hub 114 is positioned on top of the tube 112, and includes a sealing disc receiving space 130 passing through a portion of a sidewall of the hub 114. The hub 114 and sealing disc receiving space 130 are designed such that the sealing disc 150 may be fittingly secured within the hub 14.
Notably, the cannula 100 includes a plurality of collapsible bridges 120. The collapsible bridges 120 connect the cover 116 and the base 118, and include perforations 122, which assist in collapse of the collapsible bridge 120 when pressure is applied to the hub 114.
The sealing disc 150 includes a number of notches 154, as shown in
Advantageously, the inventive cannula 100 does not require a separate cap that fits over the hub 114, which can become displaced during operation and compromise the sealing properties of the cannula 100.
With respect to
The body 210 has a tube 212 at a distal end, and a separable hub 214 at a proximal end. The hub 214 is positioned on top of the tube 212, and includes a sealing disc receiving space 230 passing through a portion of a sidewall of the hub 214. The hub 214 and sealing disc receiving space 230 are designed such that the sealing disc 250 may be fittingly secured within the hub 214.
The tube 212 is a hollow, elongated structure, and extends into a bottom surface of the hub 214, in the embodiment shown. The tube 212 has a narrow external tubular wall which tapers toward a distal end of the cannula 1. The tube 212 is wide enough such that medical instruments can enter and extend through the tube 212
The hub 214 is wider than the tube 212, and has a cylindrical shape in the embodiment shown. The hub 214 has an opening 240 formed along a top surface of the hub 214. The opening 240 extends through the hub 214 and into tube 212. The opening 240 and the tube 212 are aligned, such that a medical instrument can enter into the opening 240 and extend through the hollow tube 212.
The hub 214 is a monolithic structure having a cover 216 and a base 218, which are connected together by a bridge 220. The sealing disc receiving space 230 is provided between the base 218 and the cover 216, and closed at one end by the bridge 220 and a latch 222 at an opposite end in the embodiment shown. It also possible that the sealing disc receiving space 230 is closed along multiple sidewalls limiting the openings available for ingress and egress of the sealing disc 250.
The cover 216 is generally the top section of the hub 214, while the base 218 is the bottom section of the hub 214. In the embodiment shown, the sealing disc receiving space 230 is formed in the hub 214 by cutting out a proximate middle section of the hub 214. As shown in the
However, the latch 222 projects out from the outer surface of hub 214. Additionally, the hub 214 includes a circumferential projection 224. However, while it is shown that the circumferential projection 224 encompasses the outer surface of the hub 214, the circumferential projection 224 may be positioned as to connect with the latch 222.
Since the bridge 220 connects the cover 216 and the base 218, the bridge 220 provides structural integrity to the cover 216 and base 218, yet is elastically deformable such that the cover 216 can rotate away from the base 218. The bridge 20 is also a wall and/or guide for the incoming sealing disc 250, which is positioned in the sealing disc receiving space 30 between the cover 216 and the base 218. The bridge 220 may include a key (not shown), as discussed above.
The bridge 220, being elastically deformable, and can deform in such a way that the cover 16 can rotate away from the base 18, or toward the base 18. When the bridge 220 deforms such that the cover 216 rotates toward the base 218, the cover 216 close the sealing disc 250 within the sealing disc receiving space 230. The latch 222 connects with the circumferential projection 224, and holds the cover 216, pinning the sealing disc 250 between the cover 216 and the base 218.
As shown in
Advantageously, the inventive cannula 200 does not require a separate cap that fits over the hub 214, which can become displaced during operation and compromise the sealing properties of the cannula 200.
While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention.
This application is claims benefit of the filing date under 35 U.S.C. §119(e) of Provisional Patent Application No. 61/422,431, filed Dec. 13, 2010.
Number | Date | Country | |
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61422431 | Dec 2010 | US |