Patent ID: 7285296
Filing Date: 2007-10-23
Classification: A61M

Abstract:
1. An adjustable resistance valve for a cerebrospinal fluid shunt system comprising: an actuator allowing the selection of the resistance to flow of the valve; means for selecting only one passage across the valve; and a resistance system comprising a set of passages each defining a different resistance to flow, the passages being disposed in a circle facing said selecting means, such as to guide the flow of the cerebrospinal fluid traversing said one passage of the selecting means through the selected passage of the resistance system, said actuator enabling to change the relative position of the selecting means with respect to the resistance system by a rotational movement to select the desired resistance of the valve, at least one of the lengths and the internal diameters of the passages are chosen in such a manner as to define the total resistance to cerebrospinal fluid flow of a corresponding shunt system and to cover a range of resistance to flow of 0-50 mm Hg/ml/min, the resistance system is a body of essentially cylindrical shape comprising a set of passages each having an identical internal diameter but a different length, the passages being disposed such as to form a set of passages parallel to each other and to the axis of the body, with the openings of the passages facing the rotational path of the passage of the selecting means, the body of essentially cylindrical shape comprising on its one end a recess of helicoidal shape, on the surface of which the passages depart, in order to obtain different lengths of the passages.