Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2001-07-27
2004-01-27
Zalukaeva, Tatyana (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C424S448000, C428S3550RA, C524S322000, C524S277000, C524S481000, C524S514000, C524S578000, C525S057000, C525S058000, C525S059000, C525S061000
Reexamination Certificate
active
06683120
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to bioadhesive compositions. One possible application of the compositions of the invention is as skin adhesives in the field of biomedical skin electrodes. These electrodes incorporate bioadhesive compositions which are electrically conductive. Another possible application of the compositions of the invention is as skin adhesives particularly in the field of medical skin coverings, particularly wound dressings.
BACKGROUND OF THE INVENTION
Biomedical skin electrodes are widely used in a variety of situations, whenever for example it is required to establish an electrical connection between the surface of the body of a patient and external medical equipment for transmission of electrical signals.
Modern medicine uses many medical procedures where electrical signals or current are received from or delivered to a patient's body. The interface between medical equipment used in these procedures and the skin of the patient is usually some sort of biomedical electrode. Such electrodes typically include a conductor which must be connected electrically to the equipment, and a conductive medium adhered to or otherwise contacting the skin of the patient, and they are of varying types with a wide variety of design configurations which will generally depend on their intended use and whether for example they are to be used as transmission electrodes or sensing i.e. monitoring electrodes.
Among the therapeutic procedures using biomedical electrodes are transcutaneous electric nerve stimulation (TENS) devices used for pain management; neuromuscular stimulation (NMS) used for treating conditions such as scoliosis; defibrillation electrodes to dispense electrical energy to a chest cavity of a mammalian patient to defibrillate heart beats of the patient; and dispersive electrodes to receive electrical energy dispensed into an incision made during electrosurgery.
Among diagnostic procedures using biomedical electrodes are monitors of electrical output from body functions, such as electrocargiograms (ECG) for monitoring heart activity and for diagnosing heart abnormalities.
For each diagnostic, therapeutic, or electrosurgical procedure, at least one biomedical electrode having an ionically conductive medium containing an electrolyte is adhered to or is otherwise contacted with mammalian skin at a location of interest and is also electrically connected to electrical diagnostic, therapeutic, or electrosurgical equipment A critical component of the biomedical electrode is the conductive medium which serves as the interface between the mammalian skin and the diagnostic, therapeutic, or electrosurgical equipment, and which is usually an ionically conductive medium.
Biomedical electrodes are used among other purposes to monitor and diagnose a patient's cardiovascular activity. Diagnostic electrodes are used to monitor the patient immediately and are only applied to the patient for about five to ten minutes. Monitoring electrodes, however, are used on patients in intensive care for up to three days continuously. In contrast, Holter electrodes are used to monitor a patient during strenuous and daily activities.
Although all of the biomedical electrodes just referred to are used to record cardiovascular activity, each electrode requires specific features or characteristics to be successful. Thus, the diagnostic electrode does not have to remain adhered to a patient for extensive periods but it does have to adhere to hairy, oily, dry and wet skin effectively for the five to ten minutes of use. The monitoring electrode has to adhere for a longer period of time although the patient is often immobile during the monitoring period The Holter electrode is susceptible to disruption from adhesion due to physical motion, perspiration, water, etc., and therefore requires the best adhesion and at the same time comfort and electrical performance.
In the biomedical electrodes known in the prior art the ionically conductive medium which serves as an interface, between the skin of a mammalian patient and the electrical instrumentation, ranges from conductive gels and creams to conductive pressure sensitive adhesives. However, while the conductive media can be in the form of pressure sensitive conductive adhesives, for monitoring or Holter biomedical electrodes the use of such conductive adhesives is not generally adequate on their own to maintain adhesion to mammalian skin and additional hypoallergenic and hydrophobic pressure sensitive adhesives may be employed around the conductive medium to provide the required mammalian skin adhesion. U.S. Pat. No. 5,012,810 (Strand et al.) and U.S. Pat. Nos. 4,527,087, 4,539,996, 4,554,924 and 4,848,353 (all Engel), the disclosures of which are incorporated herein by reference, are examples of documents that disclose biomedical electrodes which have a hydrophobic pressure sensitive adhesive surrounding the conductive medium.
In general, a desirable skin electrode is one which maintains good electrical contact with the skin and is free of localised current hot spots, i.e. exhibits uniform conductivity. For example, it has been found that a prior art electrode utilising karaya-gum tends to creep in use and flatten out, exposing skin to possible direct contact with the current distribution member or lead wire. A desirable skin electrode should also usually have a low electrical impedance.
As mentioned above, another possible application of the compositions of the invention is in the field of medical skin coverings, for example medical tapes, wound dressings and bandages, and most particularly wound dressings. In general, a desirable wound dressing bioadhesive composition maintains good adhesion to skin of varying moisture levels, while maintaining the dressing in position on the skin and permitting moisture and skin exudates to be transmitted away from the skin. The bioadhesive composition may suitably incorporate an antimicrobial agent, to reduce the possibility of infection of the wound. U.S. Pat. No. 5,670,557 (Dietz et al) and the prior art referred to therein, the disclosures of which are incorporated herein by reference, are examples of documents that disclose wound dressings which have a pressure sensitive adhesive which maintains the wound dressing in position on the skin.
EP-A-0850625 and EP-A-0850649 (The Procter & Gamble Company), the disclosures of which are incorporated herein by reference, describe a topical adhesive for application of functional articles to the skin, the functional articles being cosmetic or pharmaceutical delivery articles, decorative or cleaning articles (EP-A-0850649) or disposable absorbent articles (EP-A-0850625). The adhesive has particular selected rheological properties, which are expressed in part by using the difference between the elastic modulus and the viscous modulus at two fixed frequencies of applied stress, namely 1 rad/sec and 100 rad/sec.
SUMMARY OF THE INVENTION
It is an object of this invention to provide hydrogel skin adhesives possessing controlled and predictable adhesive properties which may be readily varied to suit different uses and, in the case of medical electrodes, wound dressings or similar devices, different configurations or applications.
Adhesives used for skin contact applications need to exhibit both good levels of adhesion and pain free removal. The adhesive must be skin compatible and not be harsh or aggressive towards the skin or cause skin irritation or inflammation.
The problem of achieving the desired level of adhesion is exacerbated under wet conditions. Conventional bioadhesives generally provide poor adhesion to wet skin, such adhesion generally reducing as water is absorbed by the bioadhesive. It is hence very important that the adhesive is also stable to exposure to excess quantities of liquid, such as water and in some applications in particular to urine or blood, so that it will not lose its adhesive strength on exposure to water.
Individual aspects of the invention aim, respectively, to provide hydrogel skin adhesives which provide good adhesi
First Water Limited
Peabody LLP Nixon
Zalukaeva Tatyana
LandOfFree
Bioadhesive compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bioadhesive compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bioadhesive compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3235993