PUNCTURE INDICATING GLOVES
A puncture indicating glove comprises a bilayer formed by an inner glove layer and an outer glove layer, the outer glove having an opacity in the range of 23-34%. The opacity of the over glove is controlled by the inclusion in the over glove of a fine particulate material, in particular selected from the group comprising titanium dioxide, silica, barite powder, barium sulphate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina white, basic magnesium carbonate, zinc oxide. The inner glove has a chroma range C* which is controlled to result in a glove that indicates optimally with transparent liquid and strongly coloured liquids such as blood. The inner glove has a chroma C* which is greater than 30, advantageously greater than 40, more preferably greater than 43, and in particular greater than 46.
This application claims priority to Great Britain Application No. GB 0718240.5 filed on Sep. 18, 2007 and to Great Britain Application No. GB 0801602.4 filed on Jan. 29, 2008, the contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTIONThe present invention relates to gloves, in particular surgical gloves which have puncture evident characteristics by means of which a wearer can easily identify if the glove has been pierced.
Surgical gloves perform an important function of protecting the wearer's hands from exposure to bodily fluids such as blood which might be infected and hence present a health risk as well as protecting the patient's internal organs from exposure to sweat and the like from the surgeons hands. Accordingly, the integrity of the liquid barrier formed by the glove is very important. In practice, surgical gloves are used within an environment where there is a risk of piercing, for example from scalpels and other sharp surgical implements, and it is therefore desirable for the wearer to be able to easily identify if a glove has been pierced, either before or during use, so as to minimize any potential contamination either to the wearer or the patient.
U.S. Pat. No. 5,224,221 describes a tamper or damage evident surgical glove in the form of a bi-layer glove, comprising an inner layer and an outer layer, in which the outer layer is translucent, in particular yellow, and the inner layer is a contrasting colour, in particular a darker colour such as green or black. If either the inner or outer layer is pierced, liquid can permeate between the two layers. This liquid causes two effects; the colour of the inner layer becomes more apparent through the outer layer, and or the colour of the liquid becomes apparent through the outer layer. The user sees this as a region of contrasting colour where the liquid is present between the two layers of the bilayer. However, the change in visibility produced by the indicating system in U.S. Pat. No. 5,224,221 has been found, in practice to be dependent on circumstance and in certain cases not to be that easily perceived by the wearer.
To maximize the perception of loss of barrier properties it is preferred that there is a large difference in colour or shade between regions of the bilayer that have fluid present between the two layers and regions of the bilayer that are absent of fluid. Large differences in colour result in an obvious indication of loss of barrier properties to the user. This is much preferred over a bilayer that results in a small difference in colour that is much less obvious to the user. As the user is reliant on a colour change to indicate the bilayer has been compromised it is imperative that the colour change is obvious. The present invention seeks to provide a bilayer system of the type of U.S. Pat. No. 5,224,221 that results in a large colour change as fluid ingresses into the region between the bilayers. In particular, the present invention seeks to maximize the colour change that becomes apparent in a double glove system by specifying the opacity of the outer glove and the density and strength of colour of the under glove.
The fluids generally exposed to the indicating system in the field of the invention are not of consistent colour. The colour of the fluid can range from colourless, transparent fluid such as water to strongly coloured fluid such as blood. As the fluid provides the source for indication of loss of barrier properties it is preferred to have a coloured under glove that contrasts with indicating fluid such as blood. It is also preferred that the colour of the under glove is strong enough to show through a transparent over glove when the indicating fluid is colourless and transparent.
DETAILED DESCRIPTIONThe present invention is based on the realization that the transparency of the over glove is key to generating optimal indication. The user relies on a colour change visible from the exterior of the glove on ingress of indicating fluid to indicate that the barrier properties of the bilayer have been compromised. The colour change occurs due to an increase in the amount of colour from the under glove or the indicating fluid showing through the outer glove. The intensity of colour of the inner glove does not change but the fluid ingressing into the space between the gloves results in the inner glove becoming more visible through the outer glove. This colour has to contrast with the colour of the double layer that is absent of fluid to be evident to the user. The level of contrast or difference in colour between the bilayer containing fluid and the bilayer absent of fluid is partially determined by the transparency or opacity of the outer glove. The opacity of the outer glove can be determined using a method similar to that described in ISO 2814. Measurements are made using the automatic (factory preset) controls for measuring opacity on the X-rite SP60 series. The reflectance of the outer glove is measured over a black background and then measure over a white background. Opacity=(Reflectance over black)/(Reflectance over white)×100. If the outer glove is truly transparent (that is having an opacity of 0%) the colour of the underglove will always be visible through the outer glove. If this is the case ingress of a colourless fluid will have no impact on the colour of the double layer when viewed from the outside. This results in little colour change on indication and little perception of puncture to the user. If the overglove is of low translucency (that is having an opacity of 100%) the over glove will mask the under glove. Therefore the apparent colour to the user will be of the overglove. When liquid ingresses into the space between the two layers the over glove will continue to mask the colour of the under glove and any colour associated with the fluid. Therefore there will be little change of colour on indication. Both these systems will result in a low probability that the user will detect the occurrence of a puncture in the barrier.
According to the present invention there is provided a puncture indicating glove comprising a bilayer formed by an inner glove layer and an outer glove layer, the outer glove having an opacity in the range of 15-40%.
A puncture indicating glove in accordance with the invention has the advantage that it provides particularly effective indication of liquid penetration between the layers, making it particularly easy for the wearer to identify if the integrity of the barrier formed by the glove has been compromised.
The opacity range referred to above and hereinafter is based on a range of 0%, being completely transparent, to 100% being totally opaque. Preferably, the opacity is in the range of 18 to 38%, advantageously 20 to 35% and more particularly 23 to 34%. This has the advantage that it results in the largest contrast in colour when transparent liquids ingress between the layers.
The opacity of the over glove is preferably controlled by the inclusion of a fine particulate material such as, but not limited to: titanium dioxide, silica, barite powder, barium sulphate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina white, basic magnesium carbonate, zinc oxide etc in the over glove. This can also be achieved by including finely milled organic or inorganic pigments in the overglove. The levels of materials required to achieve the desired opacity will depend on the nature of the material and particle size of the particulate material along with the amount of particulate material contained in the compounding formulation for the polymer. For this reason it is preferred to minimize the amount and size of particulate material used in the formulation of the polymer constituents to make up the glove.
The inner or under glove preferably has a chroma range C* (which essentially is the strength of colour) which is controlled to result in a glove that indicates optimally with transparent liquid and strongly coloured liquids such as blood. The chroma of the inner glove is preferably greater than 30, advantageously greater than 40, more preferably greater than 43, and in particular greater than 46. The chroma is preferably controlled by the inclusion of pigment and can be increased by choosing pigments of relatively high values of C* as well as increasing the levels of said pigment. This ensures that the maximum colour difference is observed on wetting with transparent fluid such as water or when the indicating fluid is more highly coloured as in the case when blood is the indicating medium. If the chroma of the underglove is relatively small (weakly coloured) the indicator system will not work well with fluids of low chroma (e.g. water).
The depth of density of colour is not solely controlled by C* as black or dark grey undergloves would have a relatively low C* but appear to provide good contrast on the ingress of liquid. Therefore it is preferred that if C* is low L* should be relatively low, and in particular that L* is less than 45, preferably less than 35 and more preferably less than 32
Furthermore, to encompass both the properties of C* and L* it is advantageous that the product of C* and 1/L* is greater than 0.8, more preferably greater than 1.2 and in particular greater than 1.5.
Preferably the inner glove is of a colour having a hue angle (hue angle being defined by h°=arctan (b*/a*)) in the range of 160-300°, advantageously 180-280°, more preferably 220-270° and in particular 250-270°). This has the advantage that it results in a glove in which the inner glove contrasts well with blood, so that in the case of the indicating medium being blood, the inner layer may be visible through the fluid that ingresses to give indication on puncture. To give the greatest perception of colour change it is preferred that the under glove has a colour that contrasts with red. This will also ensure that indication becomes apparent when examining the gloves in an environment that is predominantly red in colour.
In an advantageous development of the invention, a middle layer is disposed between the inner and outer layers, which middle layer has a refractive index which varies depending on its liquid content—in particular, the opacity of the material of the middle layer decreases, so that it becomes more transparent, in the presence of liquid, thereby increasing the visibility of the inner layer when liquid is present.
The inner and outer glove layers, and, indeed, if present the middle layer, are formed as separate gloves which may be connected together, for example at the cuff opening, so that the assembly is donned as a unitary glove, or may be completely separate from each other and donned separately in order, one over another.
Further details of the invention will now be provided by description of embodiments, which are given by way of example, with reference being made to the accompanying drawing, in which:
The degree of colour change can be measured by determining the value of ΔE* (euclidean distance) on the ingress of fluid between the layers—the larger the value of ΔE* the greater the colour change. This leads to and increased probability of perception of failure of barrier properties. With regards to this C*, L*, a*, b* (The three basic coordinates represent the lightness of the color (L*, L*=0 yields black and L*=100 indicates white), its position between red/magenta and green (a*, negative values indicate green while positive values indicate magenta) and its position between yellow and blue (b*, negative values indicate blue and positive values indicate yellow), and ΔE* values (all of which are universally recognized parameters with regard to colour within the art—CIE 1976 commission Internationale de l'Eclairage) may be determined using a spectrophotometer such as an SP62 provided by X-Rite of Grandville Mich. This method can also be used to determine the preferred properties of the underglove. The colour characterization of gloves can be performed using either CIELAB system or a CIELCH system. These systems have been demonstrated to reflect the perception of an average observer demonstrating the measurement in colour change is representative of that of visualized by the user of the product. The data stated in this document has been generated using an F2/2 illuminant and allowing speculative light to be included in the measurement.
ΔE*=((L*standard−L*sample)2+(a*standard−a*sample)2+(b*standard−b*sample)2)0.5
C*=(a*2+b*2)0.5
h°=arctan (b*/a*)
When performing these measurements it is important to ensure the background is consistent, as the colour of the background may affect the colour of the glove under evaluation. Measurements for this document were all performed by placing a single layer of material over either a ceramic plate or a ceramic former used for glove manufacture with L* of 81.95 to 90.69, an a* of −0.87 to 0.13 and a b* of 2.79 to 11.82. The colour of the underglove was measured on the former or plate. An overglove was placed over the underglove and the colour measured of the composite. Liquid was then injected into the gap between the underglove and the overglove and the colour determined of the composite in a region containing the liquid. It is important that sufficient liquid is injected into the gap to give a large area in which the colour of the underglove becomes more apparent through the overglove. For this purpose approximately 0.1 ml of liquid was injected into the gap between the two glove layers. Both distilled water and synthetic blood were used as the liquid. The values for ΔE* were then determined on indication using the equation above. Where L*, a* and b* for the standard refer to the values determined for the combination of the gloves with no liquid present and L*, a* and b* for the sample all refer to those measured for areas of the bilayer after injection of liquid.
Synthetic blood was used to meet the specification described in ASTMF 1862-00a. For this purpose synthetic blood meeting this specification was purchased from Johnson, Moen & Co., 2505 Northridge Lane NE, Rochester, Minn. 55906.
The various parameter value ranges and sub-ranges recited above can each individually be used in combination with the outer glove opacity defined in connection with the present invention in order to give advantageous results in terms of ease of recognition of the ingress of liquid between the layers of the glove, but in a particularly preferred embodiment, a puncture indicating glove is provided which combines some and preferably all of these parameters, at least with respect to the broadest ranges thereof defined in each case.
EXAMPLES Comparative Example:Gloves were made with varying opacity these were then put together with undergloves of varying colour. All the measurements were made using an X-rite spectrophotometer using an F2/2 illuminant. Measurements were made that included speculative light. The measurements of ΔE* were performed as described previously in this document. Gloves with high opacity were generated in comparative examples A, B, D and E. It is clearly demonstrated that all these examples give lower values for ΔE* when the indicating fluid is synthetic blood or water. Higher values of ΔE* are generated when the opacity of the over glove is optimal. Comparative example C demonstrates that the colour of the underglove is required with high C* to give good level of indication with blood and water. This example has a low value for C* and lower colour changes with low chroma indicating fluids such as water. This further exemplified in the graph of ΔE* vs. opacity.
Examples A to G demonstrate the benefit of using overgloves with optimal opacity in combination with high values for C*. Examples F and G demonstrate the benefits of the correct combination of the opacity of the overglove and colour of the underglove.
The relationship between the strength of indication as indicated by ΔE* with C*/L is further exemplified in the graph of ΔE* vs. C*/L.
Claims
1. A puncture indicating glove comprising a bilayer formed by an inner glove layer and an outer glove layer, the outer glove having an opacity in the range of 15-40%.
2. A puncture indicating glove according to claim 1, wherein the opacity is in the range of 18 to 38%, advantageously 20 to 35% and more particularly 23 to 34%.
3. A puncture indicating glove according to claim 1, wherein the opacity of the over glove is controlled by the inclusion in the over glove of a fine particulate material, in particular selected from the group comprising titanium dioxide, silica, barite powder, barium sulphate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina white, basic magnesium carbonate, zinc oxide.
4. A puncture indicating glove according to claim 1, wherein the inner glove has a chroma range C* which is controlled to result in a glove that indicates optimally with transparent liquid and strongly coloured liquids such as blood.
5. A puncture indicating glove according to claim 1, wherein the inner glove has a chroma C* which is greater than 30, advantageously greater than 40, more preferably greater than 43, and in particular greater than 46.
6. A puncture indicating glove according to claim 4, wherein the inner glove includes pigment in order to control the chroma.
7. A puncture indicating glove according to claim 6, wherein the chroma is varied by choosing pigments of relatively high values of C* and/or increasing the amount of said pigment.
8. A puncture indicating glove according to claim 1, wherein L* of the inner glove is less than 45, preferably less than 35 and more preferably less than 32.
9. A puncture indicating glove according to claim 1, wherein the product of C* and 1/L* is greater than 0.8, more preferably greater than 1.2 and in particular greater than 1.5.
10. A puncture indicating glove according to claim 1, wherein the inner glove is of a colour having a hue angle in the range of 160-300°, advantageously 180-280°, more preferably 220-270° and in particular 250-270°.
11. A puncture indicating glove according to claim 1, wherein the inner glove has a colour that contrasts with red.
12. A puncture indicating glove according to claim 1, wherein a middle layer is disposed between the inner and outer layers, which middle layer has a refractive index which varies depending on its liquid content.
13. A puncture indicating glove according to claim 12, wherein the opacity of the material of the middle layer decreases in the presence of liquid, thereby increasing the visibility of the inner layer when liquid is present.
14. A puncture indicating glove according to claim 1, wherein the outer glove includes finely milled organic or inorganic pigments.
Type: Application
Filed: Jul 10, 2008
Publication Date: Mar 19, 2009
Inventors: Simon Pickard (Irlam), Gareth Hilton (Irlam)
Application Number: 12/170,453
International Classification: A41D 19/00 (20060101);
