GB2531612A

GB2531612A - Colour-changing bandage for indicating wound infection

Info

Publication number: GB2531612A
Application number: GB1419018.5A
Authority: GB
Inventors: Nile Sobek Olivia
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-10-24
Filing date: 2014-10-24
Publication date: 2016-04-27
Also published as: GB201419018D0

Abstract

A bandage 1 includes transparent attachment means 3 for attaching the bandage to skin over a wound, a bandage pad 2 that can change color by having a dye such as Leuco dyes comprising thermo-chromic inks, the skin temperature in contact with the bandage becomes infected and heats up to an infection-indicating temperature thus changing the appearance of the inks resulting in a colour change, and a transparent barrier 4 such as a perforated plastic film between the wound and the bandage pad.

Description

Colour-Changing Bandage For Indicating Wound Infection This invention relates to an adhesive bandage for indicating early-stage infection in the wound site, changing colour with wound temperature change.

When a person receives an open wound that is not serious enough to require immediate medical attention, he or she often uses a bandage to cover the wound to stem blood flow and protect the wound from potential infection while it heals. These bandages are most commonly comprised of an adhesive covering over a bandage pad under a thin sterile plastic film.

^se of these bandages however, requires the user to constantly check the wound for visual signs of infection. This can lead to exposing the wound to the elements more often than is necessary in an attempt to monitor it. If the user is in a place away from potential medical help, such as camping or traveling in a remote area or foreign country, the risk of infection to a wound can increase with the exposure when checking the for physical signs of an infection to occur. Before physical signs of infection manifest in a wound though, there is a 1.7 degree Celsius increase in the site of the wound often accompanied by a decrease in temperature in the skin around the wound site, as detailed in "Wound and Skin Care: Infected Wounds Tipping the Balance with STONES" by C. N. Sarvis, published in the July 2007, Volume 37 of Nursing2014.

To overcome the problem typical bandages have with wound monitoring, the present invention proposes using a clear adhesive top and a bandage pad dyed in a mixture of several types of thermochromic ink which will allow for the normal range of human skin temperatures and change colour with the change in the user's skin temperature and show a difference in colour if the wound underneath the bandage reaches an infection-indicating temperature above the temperature of the surrounding skin.

Thermochromic, or colour-changing, ink reacts with specific temperature changes by causing the liquid crystals or leuco dyes in the ink to rearrange and change its apparent colour, with the change being either final or reversible. This is evidenced within "Photochromic and Thermochromic Colorants in Textile Applications" by B. S. Butola, M. A. Chowdhury, and M. Joshi published in the first Issue 1 of Volume 9 of the "Journal of Engineered Fibres and Fabrics" in 2014.

A person's average skin temperature between hypothermia and hyperthermia ranges from 32 to 35 degrees Celsius, which can be verified in 'Nanomedice, Volume 1: Basic Capabilities' by R. A. Freitas Jr. published in 1999. Bearing this in mind, a ten-part mixture of reversible thermochromic inks with temperature changes ranging between 29 and 38 degrees Celsius will cover the span of average human skin temperature in-between hypothermia and hyperthermia and changes therein due to wound infection and environment.

If no heat is applied to the bandage, the mixture makes the bandage pad appear black, a combination of the ten different coloured inks comprising the mixture. As different thermochromic inks at different temperature thresholds are activated, they will become clear, changing the colour of the overall bandage pad by allowing only the combination of the remaining coloured inks not activated to show.

When a wound underneath the bandage pad becomes infected and its temperature increases to indicate this, the portion of the colour of the bandage directly over the wound will differ from the colour of the rest of the bandage, thus alerting the user to the infection.

As all of the thermochromic inks used are reversible, this means that the individual inks used in the mixture on the bandage pad will be able to change back from a reaction, from clear back to their specified colour. This allows for normal change in skin temperature, and also for wound-infection temperature indication at lower temperatures after the skin may have been at a higher temperature.

The top adhesive layer and the bottom thin plastic layer will also keep the thermochromic ink in the tabric bandage pad trom reacting much to external temperature changes. It will be protected from the surrounding temperature by the width of the top adhesive, and the thin sterile bottom layer will allow for the most direct contact with the skin and its temperature for reactions.

The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a top view of the completed bandage with transparent adhesive plastic top layer and visible fabric bandage pad second layer, Figure 2 shows a side and lengthwise view of the completed bandage with transparent adhesive plastic top layer, fabric bandage pad second layer, and transparent perforated plastic film bottom laver, Figure 3 shows a side and width-wise view of the completed bandage with transparent adhesive plastic top layer, fabric bandage pad second layer, and transparent perforated plastic film bottom layer, Figure 4 shows a bottom view of the completed bandage with transparent perforated plastic film bottom layer, visible fabric bandage pad second layer, and transparent adhesive plastic top layer, Figure 5 shows a view of the fabric bandage pad fully dyed in the thermochromic ink mixture before any heat changes have occurred, Figure 6 shows a view of the tabric bandage pad fully dyed in the thermochromic ink mixture after all of the individual thermochomic inks have become fully activated.

In figure 1, a completed bandage 1 is shown from above with a clear plastic adhesive 3 is attached to a fabric bandage pad 2, which is visible through the top adhesive layer. The adhesive layer 3 holds the fabric bandage pad 2 in place. The bandage pad 2 is dyed with a measured mixture of ten reversible thermochromic inks of differing colours. If no heat is applied to the bandage, the mixture of different colours makes the bandage pad appear black. As each temperature range of the individual inks is activated, the colour of the bandage pad 2 will change, becoming a combination of the remaining inactivated inks.

Figure 2 is a side and lengthwise view of the completed bandage 1 with transparent adhesive plastic 3 top layer, fabric bandage pad 2 second layer, and transparent perforated plastic film 4 bottom layer. The transparent perforated plastic film 4 layer is attached to the completed bandage 1 by means of the transparent adhesive plastic 3 top layer, just as the bandage pad 2 is.

Figure 3 shows a further side and width-wise view of the completed bandage 1 with transparent adhesive plastic 3 top layer, tabric bandage pad 2 second layer, and transparent perforated plastic film 4 bottom layer. As shown, the width of the bandage is shorter than the length to allow for ease of wrapping around wounds on extremities.

Figure 4 shows view of the completed bandage 1 upside down with the transparent perforated plastic film 4 bottom layer on top, visible fabric bandage pad 2 second layer, and transparent adhesive plastic 3 top layer on the bottom. The plastic film layer 4 is perforated to allow for proper healing of the wound, and thin enough for the bandage pad 2 to be properly reactive with skin temperature.

Figure 5 shows a view of the fabric bandage pad 2 by itself, fully dyed in the thermochromic ink mixture before any heat changes have occurred. The bandage pad is indicated as appearing black, a result of the combination of the various different coloured thermochromic inks comprising the mixture used to dye the bandage pad 2.

Figure 6 shows a further view of the fabric bandage pad 2 by itself, fully dyed in the thermochromic ink mixture atter all of the individual thermochomic inks have become fully activated. The bandage pad is indicated as appearing white, as when the various different coloured thermochromic inks comprising the mixture used to dye the bandage pad 2 are activated they turn clear leaving only the white colour of the bandage pad 2.