EP1392203A1

EP1392203A1 - Intermediate layer for enhancing comfort of a user wearing usual objects on the body

Info

Publication number: EP1392203A1
Application number: EP02774442A
Authority: EP
Inventors: Andreas Richter; Karl-Friedrich Arndt; Thomas Schmidt; Michael KÖRNERT; Daniel Weber
Original assignee: Technische Universitaet Dresden
Current assignee: Technische Universitaet Dresden
Priority date: 2001-10-10
Filing date: 2002-10-09
Publication date: 2004-03-03
Also published as: WO2003032875A1; US20050038368A1; DE10149952A1; DE10149952C2

Abstract

The invention concerns an intermediate layer (2) for enhancing comfort of a user wearing usual objects on or in the body. Said intermediate layer comprises at least an element consisting of a heat-sensitive gel having a lower critical solution temperature (LCST). Under the influence of the user's body or skin temperature (T), the intermediate layer actively produces a constant modification of the contact point(s) between the usual object and the user's body (3).

Description

Description :

Name of the invention

Liner to improve the comfort of everyday items worn on the body

Technical field

The invention relates to an intermediate layer to improve the wearing comfort of articles worn on or in the body.

Particularly in the case of articles of daily use, which are often worn over a long period of time on or in the body of a person or animal, points of contact at the points of contact with the body appear which are stressed by the fastening devices, the weight of the article of use, the interactions between the body and the article of use or the like are generated. The individual, uneven body shape results in an uneven pressure distribution at the contact points, which leads to reduced wearing comfort and to impairing the well-being of the wearer, e.g. in the form of local redness, pressure and chafing, blisters, inflammation and pain.

A typical reaction of a wearer is the temporary relief of the pressure point, for example moving a carrying strap or strap, moving or removing the glasses, changing the posture or the like. However, this is not possible when using fixed everyday objects, such as bandages.

State of the art

To date, this problem has been dealt with technically with the use of cushioning media, such as foams, rubber, liquids or air, in order to enable soft storage. When using foam, rubber or the like, the contact surface is increased for the uneven body contours, an improved adaptation to the contours and a reduction of the point load is achieved. In addition, the rubber acts as a seal, which is necessary for certain applications.

For example, EP 0 852 935 A1 describes a possibility of improving bandages by adapting their shape to a part of the body. For this purpose, the bandage material is simulated by thermal deformation to the special anatomical shape by positive or negative shapes. In this way, disruptive connection points can be avoided. Materials with a thermoplastic character such as nonwovens, woven fabrics / knitted fabrics / knitted fabrics and film-like plastics with low stiffness, such as LDPE / foam, used.

However, the individual anatomical impression has the disadvantage of only one-time, personal use or, in the case of standard forms, the conditional fit.

Improved pressure distribution and shape adaptation, especially for everyday items that affect the human support system, is achieved by using ordinary gels as a cushioning medium.

DE 298 16 352 U1 deals with the use of bags filled with gel for insole shoe soles. The use of weldable, highly tear-resistant plastic foils ensures that the insole soles are resistant to pressure and insensitive to cold.

DE 200 11 334 Ul also deals with the use of a gel cushion as a damping element in an insert shoe sole. For occupational safety shoes, the use of gel cushions as a damping element is described in EP 0 774 219 AI.

WO 96 28 057 describes a shoe sole with a special structure which enables improved shape adaptation on the basis of the use of gels. The principle is based on a sandwich structure of the shoe sole, consisting of an outer, an inner and an intermediate layer. The intermediate layer consists of two types of gel. The first type of gel with viscoelastic properties is e.g. an ordinary polyurethane gel. The second type of gel below is a temperature-sensitive gel with Lower Critical Solution Temperature behavior. This gel is warmed by the influence of the foot temperature and gradually adapts to the shape of the wearer's foot through local swelling or swelling when worn.

All of the aforementioned gel-based articles of daily use avoid local pressure peaks by taking advantage of the special visco-elastic properties of gels, which ensure very good body adaptation and pressure distribution. Their main disadvantage is the exclusive use of the principle of soft storage. The problem of permanent stress from the same contact point remains unsolved. Even with the shoe sole according to WO 96 28 057, there is only a gradual adaptation to the body shape of the foot.

Presentation of the invention

The object of the invention is to develop an intermediate layer for optimal wearing comfort of intensively used items worn on or in the body for people or animals.

According to the invention, the object is achieved by the features specified in claim 1. Advantageous refinements are given in claims 2 to 13. The invention relates to applications which are based on the effect of active rearrangement with the aid of temperature-sensitive gels which are known per se. Temperature-sensitive gels fall into the class of so-called smart gels. The special peculiarity of smart gels is that their phase transition behavior reversibly changes their properties, in particular their volume or their degree of swelling, even with small changes in a certain environmental size. The swelling balance set by the smart gel can be assigned to a certain quantity of the surrounding size. Temperature-sensitive gels with a Lower Critical Solution Temperature (LCST) behavior are relevant to the invention. Gels with LCST characteristics swell at temperatures below the phase transition temperature and swell when the phase transition temperature is exceeded.

According to the invention, this behavior is used for an active intermediate layer with at least one component made of temperature-sensitive gels to improve the wearing comfort of everyday objects worn on or in the body. If the wearer wears the article of daily use on or in the body, direct contact at the points of contact results in the transfer of the skin or body temperature to the intermediate layer with the temperature-sensitive gel. If the phase transition temperature is slightly below the skin or body temperature, the phase transition temperature of the gel is exceeded and it locally swells at this point. This leads to the formation of new local contact points and a relief of the old position. In extreme cases, this can be hollow.

This process is repeated at the new contact points, while the old contact point cools down again due to the reduced heat transfer and swells again when the temperature drops below the phase transition temperature. Of course, temperature-sensitive gels also have the advantageous adhere to the visco-elastic properties of ordinary gels and therefore also guarantee very good soft storage.

The permanent rearrangement of the local contact points is a low-dynamic process, so that the wearer does not notice this effect. Depending on the application, the optimal transfer time can be between 30 s and 2 h. Longer times should be avoided, since painful pressure points can then be expected if the capillary sealing pressure is exceeded. The desired gentle-dynamic rearrangement effect only occurs with two-layer intermediate layers if the layer with the temperature-sensitive gel is arranged on the body side and the body heat can control the gel behavior unimpeded or almost unhindered.

The position of the phase transition temperature of the temperature-sensitive gels used depends on the region of the body in which the intermediate layer is to be used, since the body has typical isotherms for the different parts of the body.

The intermediate layer is preferably part of a commodity that is in constant use by the wearer, such as prostheses, hearing aids, glasses, wigs, denture replacements, or an orthopedic aid that is to be worn permanently, or a commodity that can only be worn temporarily or temporarily, such as for example an orthopedic splint, an orthosis, a plaster cast, a wound dressing, a bandage or a support belt, a compress, support stockings, support tights, orthopedic insoles, a support corset.

Another area of application of the intermediate layer is in the area of occupational, health and accident protection, for example in the case of protective masks, protective helmets, protective glasses, protective gloves, joint protectors and footwear. A further area of application of the intermediate layer is straps, for example holding straps, pull straps, carrying straps, of course also for animals, tapes, handles, carriers or supports of a piece of clothing or another article of daily use to be worn. Examples are the carrying strap or the support of a backpack, the handle of a suitcase or a bicycle handlebar, the strap or the insert of a bra, a watch strap.

Another area of application is the use of the intermediate layer in invasive medicine, for example in catheters, ports, breathing tubes, implants.

Yet another area of application is the use of the intermediate layer in mount saddles, whereby a temperature-sensitive layer can be arranged both on the side of the mount and on the side of the rider. An intermediate layer on two-wheel saddles is also useful.

Brief description of the drawings

The invention will be explained in more detail using a few exemplary embodiments.

1 shows a utility object in physical contact with an intermediate layer according to the invention in various working phases,

2 shows a basic structure of a commodity with an intermediate layer,

3 an eyeglass temple,

Fig. 4 shows the part of an inner ear hearing aid and

Fig. 5 shows the basic structure of a protective helmet. Best ways to carry out the invention

A commodity 1 not shown in FIG. 1 a, for example an inner ear hearing aid, is coated with an intermediate layer 2 which contains a temperature-sensitive gel, for example poly (N-isopropylacrylamide). The composite of inner ear hearing aid 1 and intermediate layer 2 expediently has a standard shape which is roughly adapted to the anatomy of the ear cup and the ear canal of its wearer. When worn, it is in contact with the body part 3 of the wearer, that is to say in the example of the inner ear and the auricle. Due to the non-ideal fit of the composite to the body part 3, the contact point will have local areas where the actual contact points are located. At these points of contact, pressures pi and p ₂ occur, for example caused by the inherent weight of the inner ear hearing aid, which stress the skin of the body part 3. If the body temperature T of the body part 3 is transferred to the intermediate layer 2 long enough (FIG. 1b), the gel of the intermediate layer 2 is heated at the direct contact points above its phase transition temperature of, for example, 34 ° C. and locally swells at these points. As shown in FIG. 1 c, the old parts of the contact are relieved (in extreme cases by hollow storage) and new points of contact are formed, at which the pressures p ₃ , p ₄ and p _{5 then} occur. After some time, the old contact points cool down below their phase transition temperature and swell. The described process is repeated at the new points of contact. Poly (N-isopropylacrylamide) is a temperature-sensitive hydrogel with a phase transition temperature of 33 ° C to 34 ° C and is therefore suitable for many intermediate layers according to the invention without additional treatment. However, by copolymerization or by varying the swelling agent composition, the position of the phase transition temperature can be adjusted in a known manner in a targeted manner to values between 5 ° C. and 50 ° C. and thus to practically every application covered by the invention. The intermediate layer 2 offers a practical and attractive increase in wearing and usage comfort for the areas of application mentioned in the dependent claims. However, they are by no means exhaustive, since the use of the intermediate layer is also recommended for many other applications.

The intermediate layer 2 has the basic structure shown in FIG. 2. It is enclosed by a sheathing 4, which is made of a thin, body-compatible material that meets the mechanical stresses. In addition to elastic fibers, it can also contain textile components, since correspondingly thin materials do not permanently impair the necessary heat transfer. On the side facing the body of the wearer, the active layer 5 follows the intermediate layer 2, which consists of temperature-sensitive gel, for example polyvinyl methyl ether. Polyvinyl methyl ether has a phase transition temperature of 37 ° C. The active layer 5 can be chambered, especially for very large interlayer surfaces, for reasons of effects of the heat capacity, so that local heating of one or a few chambers is possible. Chambering can be dispensed with for areas smaller than 1 cm ² , since heat capacity effects are of minor importance. The active layer 5 is to be designed in such a way that the water released during local swelling can be distributed within the intended space.

Especially for very large-area applications, the soft storage effect based on the visco-elastic gel properties can be enhanced by an additional layer 6, which consists of ordinary gels, such as polyurethane gel. This non-temperature-sensitive layer 6 of the active intermediate layer 2 is located on the side of the intermediate layer 2 facing away from the body part. The active intermediate layer 2 according to FIG. 2 can also be formed without the additional layer 6, for example for reasons of space.

In the example according to FIG. 3, the mechanical stability of the active intermediate layer 2 is ensured by a bracket part 7 of glasses. The bow part 7 is encased by the active intermediate layer 2 in the area of the pressure points with the head of the wearer. Further pressure points can be found, for example, in glasses in the nose area. In this regard, frame parts of glasses for the nostrils or the bridge of the nose can also be equipped with an active intermediate layer 2.

4 schematically shows a section through the part of an inner ear hearing device. The housing 8 is in turn covered with an active intermediate layer 2 and gives mechanical stability. The empty space 9 serves to accommodate the loudspeaker unit. Of course, the active intermediate layer 2 can be anatomically preformed.

5 schematically shows a cross section through a protective helmet, for example a bicycle helmet. The protective helmet is constructed from a mechanically stable shell 10, an inactive padding 11 and an active intermediate layer 2 on the head side. An active shape adjustment results in an improved shape adjustment, an improved fit and a better pressure distribution on the head of the wearer.

Claims

Claims:

1. Liner to improve the wearing comfort of everyday objects worn on or in the body with at least one component made of a temperature-sensitive gel with LCST behavior (Lower critical solution temperature - behavior), the liner (2) being influenced by the body - or skin temperature (T) of the wearer actively causes a constant change in the contact point (s) of the article of use with the body (3) of the wearer.

2. Intermediate layer according to claim 1, so that the intermediate layer (2) is part of an article of daily use to be worn permanently or longer.

3. Intermediate layer according to claim 2, so that the intermediate layer (2) is part of a prosthesis, hearing aid, glasses, wig or denture replacement.

4. Liner according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the intermediate layer (2) is part of a surgical or orthopedic commodity.

5. Liner according to claim 4, characterized in that the intermediate layer (2) is part of a splint, an orthosis, a plaster cast, a wound dressing, a bandage, support belt, a support corset, a support stocking, a compress or an orthopedic insert.

6. Intermediate layer according to claim 1, so that the intermediate layer (2) is part of a commodity from the field of occupational health, safety and accident protection.

7. Liner according to claim 6, d a d u r c h g e k e n n z e i c h n e t that the intermediate layer (2) is part of a protective mask, a protective helmet, protective glasses, protective gloves or a joint protector.

8. Intermediate layer according to claim 1, so that the intermediate layer (2) is part of a clothing or wearing object coming into contact with a body part of the wearer.

9. Intermediate layer according to claim 8, so that the intermediate layer (2) is part of a strap, a band, a watch strap, a handle, a carrier or a support.

10. Liner according to claim 1, characterized in that the intermediate layer (2) is part of an article of daily use from the field of invasive medicine.

11. Intermediate layer according to claim 10, so that the intermediate layer (2) is part of a catheter, a port, a breathing tube or an implant.

12. Intermediate layer according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the intermediate layer (2) is part of a saddle.

13. Intermediate layer according to claim 12, so that the intermediate layer (2) is part of a mount saddle or a two-wheeled saddle.