This invention relates to a surgical spear comprising a sponge material with a low particulate count, and to a method of manufacturing such a surgical spear.
Currently, ophthalmic and other surgical sponges are manufactured using cast blocks or sheets of PVA or cellulose sponge as a starting material. In the context of the present application, PVA sponge is a sponge made using polyvinyl alcohol as the base raw material. The blocks or sheets of sponge are typically cut into sheets or sections of an appropriate width and thickness, generally around 7 to 10 mm, and the sheets are then processed and converted into dry compressed sheets of around 1mm in thickness. The compressed sheets are injection moulded to add handles and then cut to form individual surgical sponge spears for use by medical professionals. Such sponges are known, for example, from U.S. Pat. No. 6,711,879, the content of which is incorporated into the present application by reference. Surgical spears are known for moving and positioning delicate corneal tissues and the like during ophthalmic surgery, as well as for absorbing and controlling excess fluid at the surgical site.
However, known surgical sponge spears suffer from the disadvantage that the manufacturing process, which involves cutting the sponge material, results in debris in the form of tiny sponge particles. The lattice-like structure of the sponge material makes it impossible to cut without creating such particles. Moreover, several cutting steps need to be undertaken before and after the sponge is in the compressed state, and this results in sponge particles becoming embedded in the compressed cut surfaces, only to be released when the sponge spear is used during surgery. This is because the sponge will expand when used during surgery to control and remove liquids, and the expansion will open up the lattice structure of any cut edges, thus allowing the embedded particles to escape into the surgical site. This can be particularly problematic in ophthalmic surgery procedures, where the particles can become embedded in a surgical incision, thus causing complications.
The sponge material of U.S. Pat. No. 6,711,879 is washed prior to packaging so as to reduce the amount of particulates present in the sponge after cutting. However, some debris from the cutting process may still remain embedded and has the potential to come loose when the sponge is expanded at the time of use. The sponge material is cut to size and prepared for the handles to be moulded to the sponge, the handles are moulded to the sponge, and the sponge and handles are cut and separated. Rather than packaging and sterilizing the surgical spears at this point, as would have been normal prior to U.S. Pat. No. 6,711,879, the spear is subjected to an additional set of processes, where the spear is wetted to cause expansion and then put through a washing and filtering process. Once the wash is finished, excess water is extracted from the sponge material in an extraction process, and the spear products then go through a chemical treatment rinse which resaturates the sponge material. A further extraction process is undertaken to remove the excess treatment rinse liquids, and the spear products are then loaded onto drying racks for a lengthy drying cycle. Once dry, the spears are loaded into a machine to re-press the expanded sponge material back down to its original pressed thickness (approximately 1 mm). The spears can then be inspected and packaged for sterilization. During the chemical treatment rinse, the handles will also be coated with the chemical treatment liquid, and this can leave a film or residue on the handles which is not desirable.
Although these additional steps reduce particulate, they also add a significant amount of time and man-hours to the manufacturing process, and hence result in increased costs.
An alternative method for manufacturing sponges is known from U.S. Pat. No. 6,852,258 and U.S. Pat. No. 7,229,579. These disclose a method of making a surgical sponge by introducing sponge raw material directly into individual moulds to form an individual sponge tip portion and create a finished single sponge. Additionally, while the sponge material is in an un-cured state, an individual pre-manufactured handle needs to be precisely placed into the centre of the un-cured material before it is fully cured so as to attach the sponge material to and around the handle. By adding the handle at this point in the process, there is no need to attach handles at a later time. Once the sponge material has gone through its curing cycle, the cured material is removed from the mould and needs to be processed, rinsed, washed, treated, dried, and the sponge pressed flat, down to a thinner thickness to mimic a standard sponge thickness of approximately 1 mm.
During the manufacturing process, especially with PVA sponge, harsh chemicals like formaldehyde and sulfuric acid are used in the making of the sponge material itself. After casting and curing the sponge, the chemicals must be removed before the product is safe for medical use. In this case, the washing process must also include the handle, which will have come into contact the sponge, and therefore become contaminated with these same harsh chemicals. Because the handles are part of the casting process, they also need to be neutralised and tested for chemical and residues.
Although this process produces an individual cast sponge material, which eliminates cutting, the process involves many additional steps and therefore results in a longer and more expensive overall manufacturing process.
In the standard methods of producing a PVA sponge, the sponge material is washed, neutralized and processed to remove all chemicals, cut into sheets, treated and dried for future production into spears. Therefore, the harsh chemical or treatment rinse never comes in contact with the handle portion on the spear.
Casting the individual sponge tips according to U.S. Pat. No. 6,852,258 and U.S. Pat. No. 7,229,579 also gives rise to several functional problems during use of the product by surgeons. Firstly, the way the sponge is cast onto the handle means that the triangle shape of a standard spear cannot be achieved. The sponge ends up facing in the opposite direction to that of a standard spear, therefore altering its shape, look and performance. This is shown in
Viewed from a first aspect, there is provided a surgical sponge device comprising a sponge portion and a handle portion, wherein the sponge portion is formed from an open cell foam material having an external surface, wherein the handle portion comprises a grip at one end thereof that compressively grips mutually opposed external surface regions of the sponge portion an edge of the sponge portion, and wherein substantially all of the external surface of the sponge portion is formed as an uncut external surface, except for at least one predetermined region of the external surface that is located close to the grip, the at least one predetermined region of the external surface being formed as a cut external surface.
The open cell foam material of the sponge portion is formed by a casting process in a mould. The open cell foam material may comprise a polyvinyl alcohol-based sponge material (PVA sponge), or a cellulose-based sponge, or possibly a polyurethane or other biocompatible sponge material. In all embodiments, it is important that the uncut external surface portions of the sponge portion correspond to external surfaces of an open cell foam material that has been formed in a casting process in a mould, the uncut external surface portions being formed at the interface between an interior of the mould and the liquid material from which the foam material is cast.
The uncut external surface comprises a substantial majority of the external surface of the sponge portion. It is particularly preferred that the uncut external surface comprises the parts of the sponge portion that are distal from the handle and which will typically contact a patient during use. The uncut external surface is porous, so as to allow ingress of fluid. In embodiments where the sponge portion is made of PVA sponge, the uncut external surface portions may be less porous than the open cell structure of the main body of the PVA foam material forming the sponge portion and less porous than the cut external surface portions. The uncut external surface may have a lower open area ratio than an exposed cut surface of the open cell foam material.
It is to be emphasised that uncut external surface portions of the sponge portion will be substantially free of undesirable particulate matter, since these surface portions are defined by a casting process, not by a cutting process.
However, at least one external surface portion of the sponge close to the grip of the handle is formed as a cut surface. This allows a plurality of sponge portions to be cast simultaneously in a mould, the sponge portions connected to each other at relatively small web regions that can be cut after handles have been fitted, thereby facilitating a much more efficient manufacturing process. Because the cut surface portions are located close to the grip of the handle portion and remote from the parts of the sponge portion that are actually used for absorbing fluids from a surgical site, there is a much reduced risk of unwanted particulates from the cut surface portions contaminating the surgical site.
The sponge portion may have a substantially triangular or triangular prism shape, with an apex of the triangular or triangular prism shape forming a first, pointed end and an opposed base of the triangular or triangular prism shape forming a second end which is gripped by the handle portion is attached.
Alternatively, the sponge portion may have a coffin shape, leaf shape, teardrop shape, rhomboid shape, ovate shape or may be formed as a cone or a ball.
It is important to note that, in preferred embodiments, the handle portion does not extend inside the volume of the sponge portion, and the sponge portion in use will therefore be soft and pliable and much less likely to cause damage to the site of surgery than a surgical spear in which a rigid or semi-rigid handle portion is incorporated into the inside of the sponge portion during casting of the sponge portion.
Viewed from a second aspect, there is provided a sponge web formed from an open cell foam material, the sponge web comprising a plurality of individual sponge portions each having a base edge and an opposed tip region, the sponge web having an uncut external surface, and adjacent sponge portions being connected to each other in the web at their base edges.
The plurality of individual sponge portions may comprise first and second rows of facing sponge portions arranged such that the respective tip regions of the first and second rows interdigitate but are spaced from each other by a gap.
The sponge web may further comprise a plurality of handle portions each having a grip at one end thereof, the grip of each handle portion being attached to the base edge of an individual sponge portion.
The sponge web may be formed from a polyvinyl alcohol-based (PVA) sponge material, a cellulose-based material or other suitable materials that can be cast in a mould.
Because the external surface of the sponge web is uncut, it will be substantially free of particulate matter resulting from cutting the sponge web. While some trimming of the base edges may be required, and although it is necessary to separate the sponge portions from each other at their base edges by a cutting process, the resulting cut edges and any associated particulate material will be remote from tip regions of the sponge portions, which will be in contact with a surgical site during use of the surgical spears thus formed.
Viewed from a third aspect, there is provided a method of manufacturing a surgical sponge device comprising a sponge portion and a handle portion, the method including the steps of:
i) providing a mould configured to define a plurality of voids that are connected to each other only along at least one edge portion of the mould;
ii) filling the mould with reagents selected to generate an open cell foam material within the mould, the open cell foam material taking the form of a plurality of sponge portions having shapes defined by the plurality of voids, the sponge portions connected to each other only at base regions thereof corresponding to the void connections in the mould, the open cell foam material having an uncut external surface where it contacts the mould;
iii) removing the open cell foam material from the mould;
iv) washing and treating the open cell foam material;
v) subsequent to step vi); connecting multiple handle portions to the open cell foam material at the base regions of the sponge portions and cutting the open cell foam material to separate the open cell foam material into a plurality of surgical sponge devices, each device having a handle portion connected to a sponge portion formed of the open cell foam material having the uncut external surface formed substantially all of its external surface except for at least one predetermined region of the external surface that is located close to the point of connection of the handle portion, the at least one predetermined region of the external surface being formed as a cut external surface, wherein the handle portions each comprise a grip at one end thereof that mechanically grips mutually opposed external surface regions of the sponge portion an edge of the sponge portion.
The sponge material may be a polyvinyl alcohol-based sponge material (PVA sponge), or a cellulose-based sponge, or possibly a polyurethane or other biocompatible sponge material. The reagents required to form such sponge materials in a mould are known to those of ordinary skill in the art. Generally, the reagents comprise a curable liquid material (comprising, for example, PVA or cellulose or the like) and a pore forming agent. The pore forming agent may be a foaming agent that generates bubbles within the liquid material, or may be a soluble solid material such as starch or salt particles that can be washed away after curing to leave voids or pores in the sponge material.
The mould preferably comprises a single mould cavity that can easily be filled in one step with reagents selected to generate an open cell foam material within the mould.
It will be appreciated that the special technique of using a mould with a plurality of voids that are connected to each other only along an edge portion of the mould results in a web of open cell foam material comprising a plurality of surgical sponge portions that are connected to each other only at regions that are remote from the regions that will form the tips of the finished surgical sponge devices. This means that when the individual sponge portions are cut from the web, the cut surfaces will be small and remote from the working tips, thus reducing the risk of particulate contamination of a surgical site during use.
The mould may have a generally saw-tooth configuration, each void comprising a tooth of the saw-tooth configuration. A web of sponge material formed in such a mould will thus have a complementary saw-tooth configuration, each tooth defining a sponge portion of a surgical sponge device, with a pointed tip that has an uncut external surface due to contact with the interior of the mould. The teeth of the web of sponge material are joined together at base portions remote from the pointed tips. In some embodiments, the tips may be blunt rather than pointed. Instead of a saw-tooth profile, the mould may be configured to provide a sinusoidal or other shaped profile.
In one embodiment, a double-sided mould may be used. The double-sided mould comprises a central wall following a saw-tooth, sinusoidal or other appropriate path, thus defining two sets of complementary, inter-engaging voids. This allows two webs of sponge material to be moulded simultaneously using a single mould, thereby helping to improve production efficiency.
By way of the methods disclosed above, it is possible to form webs of sponge material each comprising a plurality of triangular surgical sponge portions each having an uncut external surface, the triangular surgical sponge portions joined to each other only at adjacent base portions remote from the apexes of the triangular sponge portions.
The mould may define a plurality of voids having shapes other than triangular, for example a coffin shape, leaf shape, teardrop shape, rhomboid shape, ovate shape. In some embodiments, the voids may be formed as cones or balls.
Where inner surfaces of the mould are smooth, the resulting uncut external surface on the web of sponge material will also be smooth. It is possible to provide a textured uncut external surface by using an appropriate textured surface on at least parts of the inner surfaces of the mould. Textured uncut external surfaces may be preferred for some applications.
After removal from the mould, the webs of sponge material can be washed and chemically treated in the conventional manner, with the sponge portions remaining connected to each other at their base portions.
The washed and treated webs may then be dried and pressed or at least partially pressed to a desired thickness, for example to a thickness of around 1.0 to 2.0 mm, for example 1.5 mm. In in some embodiments, it may be preferred to leave the centre unpressed, while pressing the base where handles will be attached to a thickness of, for example, approximately 1.4 mm. The results of this press will leave the triangle sections expanded in the finished product, which is preferred by some surgeons.
Handle portions may then be attached to the base portions of the surgical sponge portions. This may be facilitated by inserting the pressed web into an injection mould. The handle portions may be configured with gripping portions for gripping the base portions of the surgical sponge portions. By attaching the handle portions at this stage, the handle portions are not subjected to the harsh chemicals of the sponge manufacturing process during casting, or to the chemicals used during the stage of chemically treating the web of sponge material after manufacture. This means that it is not necessary to test for and, where necessary, neutralise such chemicals on the handle portions later on, nor to remove possible residue from any final chemical treatment, thus improving manufacturing efficiency.
Once the handle portions have been attached, the individual surgical sponge portions may be cut from the web by cutting through the connecting base portions. Additional cuts may be made to shape the base portions as desired, provided that the cuts are made only in the region of the base portions adjacent to the points of attachment of the handle portions. In some embodiments, all of the individual sponge portions may be cut simultaneously by using a plurality of blades. It will be noted that the amount of cutting is significantly less than would be the case if the sponge portions were cut out of a sheet or strip of sponge material, and also that substantially all of the external surface of each sponge portion that is intended for contact with a surgical site will comprise an uncut external surface as a result of the sponge casting process. This helps to reduce or eliminate particulate contamination by a significant amount.
Once the surgical sponge portions with attached handle portions have been cut from the web, they can be inspected for quality control, sterilised and packaged for subsequent use.
An advantage of embodiments of the present disclosure is that the novel combination of casting a web of sponge material, subsequently affixing handles, and then performing minimal cutting of portions of the sponge material that will not come into contact with a surgical site means that the speed of production is significantly faster and cheaper than attaching individually cast sponge members to separate handles, without significantly increasing the risk of particulate contamination. Furthermore, attaching the handles after the sponge material has been cast and treated means that there is no risk of contamination of the handles with harsh sponge treatment chemicals.
Further advantages will be apparent from the following detailed description.
Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
The surgical spear 1d of
Each of the sponge portions 2a, 2b, 2c and 2d has an uncut external surface 10 extending over substantially all of the external surface other than areas close to the grips 6 of the handle portions 5.
In each of
Pressing the sponge web 7 also facilitates the attachment of the gripping members 6 of the handle portion 5 to the sponge portion 2.
As shown in
Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
Number | Date | Country | Kind |
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1602483.8 | Feb 2016 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2017/050121 | 1/19/2017 | WO | 00 |