MEDICAL DEVICE ADHERING TO THE SKIN

Abstract: A medical device is attached to a patient's body surface by means of an adhesive layer (2) which is fixed to the device only by a part of its area, preferably only by its central area.

Description: MEDICAL DEVICE ADHERING TO THE SKIN The invention relates to a medical device comprising a housing with a rigid base which is fixed on the patient's skin by means of an adhesive layer for temporary wearing on the body. Devices of this kind are, for example, transducers or transdermal injection or infusion devices, etc. In order to fix them, the application surface is provided with an adhesive coating which is usually annular and has an outside diameter corresponding to the device. The adhesive layers usually adhere to the skin very well, but if the device is worn for any length of time and is subject to appreciable movement the adhesive layer becomes detached starting from the edge. Attempts have been made to counteract this by increasing the adhesive surface, so that its outside diameter is larger than that of the device. However, this also has disadvantages, so that no satisfactory solution of the problem has hitherto been found. The object of the invention is to solve this problem. To this end, according to the invention, the adhesive layer is fixed to the device by a reduced surface in comparison with the adhesive surface facing the skin. Preferably, this gives an outer annular zone of the adhesive layer where the latter is not connected to the device. One exemplified embodiment of the invention is described hereinafter with reference to the accompanying drawing. The single Figure is a diagram of a transdermal injection system worn on the patient's skin for a given time, e.g. a number of days. The injection mechanism including the pump and active substance reservoir is located in a housing 1 . The latter is fixed on the patient's skin H by means of an adhesive layer 2. The adhesive surface 3 of the adhesive layer is of the same size as the underside of the housing 1 . The surface by which the adhesive layer is fixed on the housing 1 on the side remote from the adhesive surface 3 is smaller than the latter. The adhesive layer is not connected to the housing 1 in an outer zone 4. This zone is annular and extends from the outer edge inwardly by about 5 to 10 mm. It has been found that this configuration does not result in detachment from the skin even when worn for long periods and subjected to extensive movement.

Claims: Claims 1. A medical device comprising a housing with a rigid base fixed to the patient's skin by an adhesive layer for temporary wearing on the body, wherein the adhesive layer (2) is fixed on the housing (1 ) by a reduced surface in comparison with the adhesive surface (3). 2. A medical device according to claim 1 , wherein the adhesive layer (2) is not connected to the housing (1 ) in an outer annular zone (4).

Inventors: HADVARY PAUL, TSCHIRKY HANSJOERG, HADVARY, PAUL, TSCHIRKY, HANSJOERG
Applicants: HADVARY PAUL, HOFFMANN LA ROCHE, TSCHIRKY HANSJOERG, F.HOFFMANN-LA ROCHE AG, HADVARY, PAUL, TSCHIRKY, HANSJOERG
Application year: 1996
Main classification: A61M5
IPC codes: A61F13, A61K9, A61M5, A61M37