Disposable puncture and cut resistant surgical gloves

Abstract

A cut and puncture resistant surgical glove having puncture resistance of over 2,000 grams with flexibility, the glove comprising a glove within a glove with the puncture resistant material being placed between the inner and outer glove. The resistant material retained in place without impairing the glove flexibility.

Description

REFERENCE TO PRIOR APPLICATION

This application claims the benefit of provisional application No. 61/269,472 filed on Jun. 25, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cut and a puncture resistant surgical glove to prevent the accidental transmission of disease to a surgeon, by needle stick injury, especially to prevent transmission of the AIDS/HIV virus. The glove could also be used by other health care workers for the same purpose and also to prevent the transmission of other diseases, such as hepatitis C, and other viral and bacterial infections.

2. Description of the Prior Art

The need for a puncture and cut resistant surgical glove became apparent with the beginning of the AIDS/HIV era. Prior to that, the occasional accidental needle stick injury to the surgeon was of little concern. Subsequently, however it became a potentially fatal wound.

This then led to the passage by Congress of the Needlestick Safety and Prevention Act (Pub. L. 106-430) in 2000. Many useful and effective devices relating to syringes and intravenous connectors were brought to the market. However, and to the present date, there has been no protective glove (puncture and cut resistant) which approaches the flexibility, elasticity and tactile transmission of touch of the standard latex glove while satisfying the conflicting demands of puncture resistance and flexibility. Since meeting such requirement remained elusive, one of the early efforts was a glove with a leather palm surface, but only a knit cover over the dorsal surface, which has no puncture resistance. Other efforts to provide a glove meeting the above requirements have similarly been unsuccessful. The effectiveness of the prior art gloves is reviewed in an article in the Journal of Biomedical Materials Research Part B: Applied Biomaterials, Volume 33, Issue 1, pages 41-46, Dec. 6, 1998 and titled “Devices Evaluation. Needle puncture resistance of surgical gloves, finger guards, and glove liners”. The article states essentially that the unique protective materials disclosed have a limited distribution over the hand and thus the surgeons hand remained susceptible to inadvertent needle puncture.

The puncture resistant property thus must cover the entire hand, dorsal (back of hand) and volar (palm of hand). There are some industrial gloves which have good puncture resistance, but are very thick and bulky. None of these gloves claim to be surgical gloves. An example is Hexarmor®, a protective glove sold by Performance Fabrics, Inc. Grand Rapids, Mich. which has been proposed for use in drug searches for law enforcement personnel but not as a surgical glove. At the other extreme, (good flexibility, but no puncture resistance) is the use of “double gloving” for protection of the surgeon. This retains the flexibility of latex, but virtually no cut or puncture resistance.

A variation of this glove is to insert a germicide between the inner and outer glove but has also been shown to be ineffective. Dupont Kevlar® fiber in a very tight weave was found to have some resistance to puncture, but required at least seven to ten layers for significant protection. At that thickness, or number of layers, the fabric has virtually no flexibility, and would not conform to a compound curve. Additional gloves are disclosed in the following patents:

U.S. Pat. No. 6,517,659 to Vanderworth describes a method for fusing a spot of a woven material to form a puncture resistant material in multiple layers.

U.S. Pat. No. 4,935,260 to Shlenker discloses the use of a germicide between the two layers of the glove.

U.S. Pat. No. 5,317,759 to Pierce discloses a “textured” inner glove of latex with “pillars”. It appears to be effective for only curved needles. Also, if the latex is soft enough for flexibility, it is doubtful that it will stop a needle.

U.S. Pat. No. 5,070,543 to Beck discloses puncture resistant material that covers only part of the hand.

U.S. Pat. No. 6,370,694 to Michelson discloses a leak detection mechanism.

U.S. Pat. No. 5,601,895 to Cunningham discloses a flexible puncture proof material. This lacked adequate flexibility and tactile transmission.

U.S. Pat. No. 6,272,687 to Cunningham discloses a puncture resistant surgical glove using multiple layers of woven metal foil or multiple layers of a very thin polymer woven. This was labor intensive and therefore it was not economically feasible, as a disposable.

The need for protective surgical gloves remains unchanged. After fifteen years of searching by the immunologists there is still no AIDS vaccine. The presently available gloves are not effective as a glove for the surgeon and surgical nurses which has all of the needed properties as noted hereinabove.

SUMMARY OF THE INVENTION

It is the object of this invention to provide a cut and puncture resistant surgical glove, and, to provide the methods for producing the cut and puncture resistant glove. It consists of an (off-the-shelf) surgical glove, which forms the inner and an outer glove of latex (or other polymer), which has confined between the two gloves, a puncture resistant material. The material is a polymer (Mylar) which is very thin (0.0003″) and contains ferrite, an iron containing mineral. The actual material which was successfully utilized was microcassette audiotapes. This had the tensile strength of Mylar and the magnetic sensitivity from the ferrite on the audiotapes. The number of layers of the Mylar required for the desired puncture resistance (1,500 to 2,000 grams) is seventy layers for an aggregate thickness of 0.0031″ or 31 mils. Sample prototypes of the Mylar were tested to prove the feasibility of producing the glove of the present invention. The layering was achieved in the following manner. An aluminum sheet 3/16 thick and 6″×6″ was used, 3/16″ holes were drilled with 1/16″ space between the holes. Special high intensity permanent magnets were obtained from K&J Magnetics, a Neodymium, D31 N50. (A single one of these magnets has a lifting force of 2.4 pounds when in contact with iron). The size used was a disc 1/16″ thick and 3/16″ in diameter. Three of them were placed into each hole in the aluminum sheet and were anchored with epoxy. The polarity of each disc was in the same direction. The discs were then covered with glove latex on one side, representing the “inner glove”. The same technique was used to produce the final product. In particular, magnets were embedded one surface of an aluminum former anf glove latex used to cover the magnets. The entire assembly was then placed in a water filled tank (about one gallon). The “units” of Mylar were then sprinkled on the surface, and sank, in a random fashion, producing a substantially uniform thickness of each. Due to the strong magnetic field, the units remained firmly attached to the former. (The water had been mixed with 50% glycerin, which was added to prevent drying in the completed glove, and resultant decrease in shelf life).

The final step in the formation of the puncture and cut resistant glove is to add the “outer glove” latex. The two latex surfaces are bonded with rubber cement, (on the ½″ margin only), while applying firm pressure over the entire surface, to expel any excess water or air. The dimensions and shape of the units are relevant to the process. It was found that a rectangular shape provided greater stability/prevention of migration of the units, at the flexion creases of the hand. The optimal dimensions were 4 millimeters wide and 15 millimeters long. Sample prototypes showed exceptional flexibility and puncture resistance of over 2,000 grams.

The definitive product, and the subject of this invention, is a full hand surgical glove, with cut and puncture resistance covering the entire surface of the hand. It satisfies all of the requirements for cut and puncture resistance, as well as flexibility, elasticity, minimal thickness and excellent tactile transmission.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention as well as other objects and further features thereof, reference is made to the following description which is to be read in conjunction with the accompanying drawing therein:

FIG. 1 illustrates a perspective view of a plate used to make the prototype sample material of Mylar;

FIG. 2A illustrates a cross section of a single hole in the plate with three of the magnets in place;

FIG. 2B illustrates a top view of the single hole in the aluminum plate;

FIG. 3 illustrates a side view of the sedimentation tank utilized to form the samples of the prototype material;

FIG. 4A illustrates a simplified cross sectional view of the material of the present invention and FIG. 4B is a top view of the finished sample prototype material;

FIG. 5 illustrates a schematic view of the entire process for forming the puncture resistant material on a standard latex surgical glove in accordance with the teachings of the present invention;

FIG. 6 illustrates the method of applying the outer latex glove, after the deposition of the units on the inner glove;

FIG. 7 illustrates the final stages of the fabrication of the glove;

FIG. 7A illustrates a cross-sectional view through the glove cuff area showing the completed glove;

FIG. 7B illustrates a cross-sectional view through the bonded area of the inner and outer glove at the level of the cuff;

FIG. 7C illustrates a cross-sectional view through the temporary strap area;

FIG. 8 illustrates a schematic of a device used to do the puncture testing of the materials used in the glove formed in accordance with the teachings of the present invention; and

FIG. 9 illustrates the forces involved in controlling excess movement of the units in the glove.

DESCRIPTION OF THE INVENTION

As used herein, the term “unit” denotes the puncture resistant element. This is preferably made of a polymer containing ferrite. The term “former” is used for the hand shaped male mold used for making latex surgical gloves and is made of ceramic or aluminum. The present invention utilizes standard off the shelf latex surgical gloves. Typically this would be a size 8 for the inner glove and size 8½ for the outer glove, about one half sizes larger to accommodate the thickness of the units.

The aluminum “former” allows the drilling of holes which holds the magnets as described hereinbelow. In order to achieve maximal flexibility, the units should be small, in the range of 3 by 3.5 millimeters. They cannot be used with a bonding polymer as a matrix, forming a composite, since this will markedly decrease the flexibility of the material. The shape of the unit is important, discs or small squares tending to form gaps with repetitive flexing of the fingers. A rectangle is the optimal shape, and with the length being three times the width, the preferred dimensions are 4 mm×15 mm. The rectangle shape and its random orientation prevent gaps from forming. The thinner the material of each individual unit will provide greater flexibility in the aggregate unit configuration.

Referring now to FIG. 1, aluminum sheet 1, 6″×6″× 3/16″ thick is illustrated. The 3/16″ thickness is selected to facilitate the fabrication of the sample prototype material, which then accommodates three high intensity permanent magnets, 1/16″ thick and 3/16″ in diameter. The magnets that were successfully utilized were made of Neodymium D31 N50, fabricated by K&J Magnetics. Three of these were placed in each hole of the 2″×3″ array 2 of the aluminum sheet member 1 and then secured with epoxy.

FIG. 2A is a cross section of a single hole with magnets and FIG. 2B is the top view. The polarity of all the magnets were the same, shown as north facing up. Member 1 was then covered with a sheet of glove latex and secured on the back of the member with tape and represents the “inner glove”.

The entire assembly is then placed in the tank or sedimentation chamber 7. The Mylar units then were sprinkled on the surface of the water, sinking in a random distribution, producing a uniform thickness of the units on the surface of member 1.

Due to the strong magnetic force, the units remained firmly attached to the magnets in the aluminum member 1. Units which fall to the side of the magnets would join the others on the magnets when the water was agitated by stirring.

FIG. 4 illustrates an exploded cross-sectional view of the glove material of the present invention with outer glove 8, the multiple layers of units 9 and inner glove 10.

FIG. 8 illustrates a puncture testing platform using hand held dynamometer 40. The testing was done with a #20 medical needle 48, connected to the dynamometer. Reset button 41 is engaged after a sample 43 is tested. A sheet of Neoprene rubber (about 30 mil thick) 44 is used as insulation. The electrical circuit consists of battery 46 connected to the alligator clip on the medical needle. The base 45 comprises metal, which conducts current to an indicator light 47 when the circuit is closed. If/when needle 48 penetrates sample unit 43, it touches the metal platform 45 and lights indicator light 47. The reading is then recorded in grams of force. Unit 43 had the following properties:

A. Material Comprising 40 Mylar Layers

Thickness: 20 mil, including inner and outer glove latex

Puncture Resistance: random series: 1,200 gm, 1,400 gm, 1,600 gm

Flexibility: Excellent

Conforms to a compound curve of a 5 millimeter radius

B. Material Comprising 70 Mylar Layers

Thickness: 30 mil, including inner and outer glove latex

Puncture Resistance: random series: 2,000 gm, 1800 gm, 1,600 gm

Flexibility: Excellent

Conforms to a compound curve of a 5 millimeter radius

Note that the material can be formed of layers other than the 40 and 70 set forth hereinabove.

The units form a suspension in water with turbulence since the Mylar has a specific gravity of only 1.4.

FIG. 5 is a schematic view of the inner glove in place, on the former. The upper tank 12 is the mixing tank. The units 11 are poured onto the surface of the water (50% glycerin) and are suspended by the mixer motor 13. The suspension then flows out via the outflow pipe 14, into the depositing tank 15. The units of the suspension enter at the top of the tank and are in a random distribution as they are pulled down by gravity. The hand/former 16 is placed in a “fingers up” position, which ensures that the tips of the fingers will receive an adequate exposure to the units. Magnets are embedded over the entire surface of the former. Even though the sides of the former are in a vertical position, the magnet attraction is strong enough to capture them. Any units which are not captured on the first cycle through will re-enter in subsequent cycles. The total number of units which will be required for each glove is determined as a function of the surface area of the former, the surface area of the individual units, and the number layers required.

After leaving depositing tank 15, the suspension and remaining units are returned to the mixing tank 12 via pipe 19, with the action of the pump 21 via pipe 22. The many small circles on the former 16 represent the magnets 17 and the small rectangles representing the units 18.

An aluminum former must be selected of a size for which an off-the-shelf commercially made glove is available with the precise size and shape which will fit. The aluminum former is typically cast aluminum with a wall thickness of about ¼″. This would not preclude the custom making of a latex glove with a finer degree of size selection. Note that formers made of material other than aluminum can be used.

It is necessary to drill 3/16″ holes over the entire surface of the former, with a 1/16″ spacing between the holes. Each of the holes is then filled with three Neodymium magnets. The magnets should be flush with the surface of the former. The magnets will also be secured by a coat of epoxy.

FIG. 6 is a schematic view of the next step of the glove forming process. It should be noted that there remains a thin film of the water-glycerin liquid covering all of the units and has the effect of compressing the layers against each other by surface tension. This compressive force is enhanced by the magnetic attraction. This step is used after the units have been deposited on the former 16, (and also cover the inner glove). In order for the units to remain firmly in the grip of the magnets and minimize the possibility of inadvertent displacement, device 40 is used. Device 40 consists of tank 23, preferably transparent, with a removable lid 24, and a vacuum line 28 to provide negative pressure. The second glove, or outside glove 27, is passed through lid 24, the lid then being placed on the tank 23 for an air tight seal. The cuff 30 of the glove is then pulled over the brim 25 and the bead 29 of the glove is secured under the in-curved brim under tension. The base 30 of the former 16 remains outside of tank 23. Negative pressure is then slowly started and held at that level when the glove is enlarged. This enlarged outside glove 27 allows easy insertion of the assembled inner glove with the units deposited on the latex glove positioned on the former. The negative pressure is then released, allowing the elastic recoil of the outside glove to add compression to the units.

Note that other materials can be used for the inner and outer gloves, such as polyvinyl chloride, polyethylene and polypropylene.

FIG. 7 is the final step in the process. The inner glove, units and the outer glove 27 are still on the former 16. Due to the rather strong magnetic force holding the glove to the former, specific forces are required for its removal. As shown in FIG. 7, the completed glove remains on the former.

In FIG. 7A, the cross section is through the completed area 37 of the glove and the dashes show the units, the solid lines the inner and outer glove. The glove is being displaced peripherally by the compressed air, represented by the stippled area 32. The vertical segment of the air channel, which comes to the surface of the former, is shown at 31. The line between the section with units and the area where the inner and outer layers are bonded together is 36. In the area of the bond, the solid line 33 is the inner glove and the wavy line 34, is the outer glove. FIG. 7C shows the area with a strap. This makes a (temporary) air seal, which maintains the air pressure until the expansion of the glove releases the glove from the magnetic attraction and is then removed from the former 16.

An unexpected property of the cut and puncture resistant proof of the material, fabricated as set forth above, is that when a compass is passed over the sample, the needle of the compass was markedly deflected. This was confirmed by repeated passes of the compass. This occurred because the magnetically sensitive units with ferrite had retained the magnetic pattern from exposure to the high intensity magnets. In addition to the purely mechanical forces described hereinabove, this greatly enhances the compression of the units on each other, thereby adding to the stability of the glove and increasing its puncture resistance.

FIG. 8 shows how some unusual force elements control the movement of the units, but without excessively limiting their horizontal excursion. Numerals 50 and 52 represent the inner and outer latex glove, respectively and 51 represents the units as seen on edge. It should be noted that the space formed by the inner and outer glove forms an air tight chamber, once the final seal and the cuff level is made. The large arrows 49 and 54, represent ambient air pressure, which cannot be overcome, and will not allow the inner and outer glove from being separated. This means that the units will be maintained in close contact, which is required for maximal puncture resistance. More importantly, it confines the units in the vertical axis of the glove wall. The force limiting excessive displacement in the horizontal plane is the edge-to-edge contact of the units. This force is shown as the large arrows 55 and 53. However, the sliding of one unit on the other unit is facilitated by the lubrication provided by the water/glycerin film. While the magnets performed the function of capturing and immobilizing the units to form the glove, the sealing of the glove, at the cuff area, transferred that function to the combination of ambient air pressure, edge-to-edge contact and the effect (vapor pressure/surface tension) of the water/glycerin fluid. Also, the edge-to-edge effect, applies to any part of the glove, since the wrist, palm and digits are cylindrical in shape, and form a circle of the units.

Another feature of this design, is the fact that it is possible to vary the puncture resistance over a wide range, by regulating the number of layers of units which are used. This would permit “fine tuning” of the trade off between flexibility and puncture resistance.

All of the individual steps, as described above, readily lends themselves to computer controlled automation. There is no labor intensive phase to the fabrication of the glove. The materials used would permit sterilization by autoclave or radiation sterilization.

The present invention thus provides a low cost surgical glove that prevents the transmission of HIV and other pathogens to surgeons and other health providers by accidental needle stick.

Since tensile strength is a determining factor in puncture resistance (in multiple layer thin films) other polymers, such as Kapton, (a polyamide) could replace Mylar. Kapton is available in thin films used for audio and video recording. The tensile strength of Kapton is about 30% greater than Mylar, and the puncture resistance on comparison testing showed a comparable difference. The use of Kapton thus permits the making of a thinner glove and therefore one with greater flexibility.

Although a target for puncture resistance was set at 1,500 to 2,000 grams, this is most likely excessive. The anticipated range of most of the needle impacts would be from about 100 grams to about 800 grams. As noted above, the 40 layer glove shows ample protection and provides significant advantages over “double gloving” commonly used, which has essentially no puncture or cut resistance.

While the invention has been described with reference to its preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its essential teachings.

Claims

1. A cut and puncture resistant surgical glove comprising:

first and second surgical gloves forming an inner and outer glove, respectively;

puncture resistant units being deposited in the space between said inner and outer gloves, said units being held in place by a magnetic force;

a hand shaped former to support and retain said units in a position on the outer surface of said inner glove;

means for combining said outer glove with the inner glove on said former to form a completed surgical glove; and

means for removing said completed glove from said mold.

2. The surgical glove of claim 1 wherein said units comprise layers of ferrite containing Mylar.

3. The surgical glove of claim 1 wherein said units are magnetized when deposited on the outer surface of the inner glove by the force produced by magnets embedded on the surface of said former.

4. The surgical glove of claim 2 wherein the number of Mylar layers is in the range between 40 and 70.

5. The surgical glove of claim 4 wherein the thickness of said 70 layer Mylar is about 0.030 inches and the thickness of said 40 layer Mylar is about 0.020 inches.

6. A method of fabricating a cut and puncture resistant surgical glove comprising the steps of:

providing a metal former having a plurality of holes formed therein;

inserting magnets in said holes;

securing said magnets in said holes;

covering the surface of said former with a latex glove forming a first assembly;

placing said first assembly in a chamber having liquid therein;

distributing a plurality of puncture resistant units on the surface of said liquid;

placing an inner glove mounted on said former in said chamber;

the magnets securing said units to the surface of said inner latex glove;

removing said former with the inner glove in place and coated with said units from said chamber;

positioning a second glove member over said inner glove to form a second assembly; and

removing said mold from said second assembly to form said surgical glove.

7. The method of claim 6 wherein said puncture resistant materials comprise ferrite containing Mylar.