The invention relates to a carrier system for a body-worn object, in particular a medical instrument with a flexible carrier plaster comprising a sheetlike carrier ply and on the lower side thereof an adhesive layer comprising a pressure sensitive adhesive and adherent to the skin of a body part by contact pressure, and with a specifically rigid assembly platform arranged on the skin remote upper side of the carrier ply. The invention further relates to a method of producing and to the special method of using such a carrier system.
Such medical devices and applications generally require the highest possible degree of quality and reliability. The materials used for this have to meet a wide diversity of needs: they need to be, for example, biologically compatible and/or inert as well as corrosion and temperature resistant and they need to work flawlessly under a very wide range of conditions. This dictates strict requirements to be met by such systems and their method of making. Adhesives like all other materials directly employed on the human body in the field of medicine have to conform not just to very high quality standards but also to various statutory regulations; the same applies to the manufacturing operation as a whole.
A known biomedical engineering solution in the field of continuous glucose monitoring (CGM), insulin delivery systems (IDS) and electroencephalography (EEG) probes is to connect the carrier plaster and the instrument by ultrasonic welding. “Standard plasters” comprising fleece are employed here, reaching a wear period of up to 4 days and in some cases even 5 days. Such standard plasters have a maximum pressure sensitive adhesive add-on of less than 80 g/m2. Owing to the long period of wear or the high load on the body, the plasters gradually become detached starting at the edge. Patients trying to achieve a long period of wear in particular constantly have to restick or overstick the plasters, or else the plasters fail prematurely. The cause for this early failure resides not only in the use of standard plasters, which are not designed for such a long period of wear, but also in the bonding technique of ultrasonic welding. This involves the punctuate input of high heat causing the carrier material, which consists of plastic, to melt slightly (T greater than 130° C.). But this leads to some local decomposition of the carrier material, thereby reducing the effective adherend surface and causing internal stresses to build up in the adhesive film. Since visco-elastic systems are concerned, this leads to detachment of the plaster from the body. The effective adherend surface of the plaster with regard to the body is diminished as a result. This is frequently the case in the region underneath the medical instrument, which is actually supposed to adhere particularly well to the skin given the envisioned function, for example contact adherence of a skin electrode.
EP-A 1 923 081 discloses an infusion device for insulin, said device comprising a catheter head which is attachable to the skin via a plaster and on its upper side has a connector to releasably and rotatably plug in an insulin pump, wherein complete attachment to the body is only established by direct tacky attachment to the skin of peripheral regions of the insulin pump which extend beyond the plaster. Unspecified skin-compatible adhesives are said to be employed. While wear-appropriate orientation of the pump on the body is achievable as a result, secure attachment does require the employment and handling of additional skin adhesives at the use site.
US 2011/257997 A1 describes a device for medicating a patient, the device comprising a two-part housing comprising a base part for attachment to the skin and an upper part which is mobile and connectable thereto, the two parts being releasably connected via a positive mechanical form-fit or optionally adhered together. As a joining region, only protruding molded structures are disclosed, rendering manufacture and assembly rather costly and inconvenient.
USPTO Backgrounds
USPTO Backgrounds