A surgically implantable device and stepping motor apparatus which may be used therein.

摘要

Apparatus is described which is capable of venting cerebrospinal fluid in the treatment of hydrocephalus or of shunting other body fluids. A surgically-implantable shunt valve (114) has a housing constructed of a surgically-implantable material with an inlet and outlet chamber within the housing. The housing includes inlet and outlet ports communicating with the inlet and outlet chambers respectively for connecting the inlet and outlet chambers to external catheters or other fluid conduits. An aperture (108) communicates between the chambers. The aperture has a circular periphery forming a circular valve seat. A valve member (110) of diameter larger than the circular valve seat is biased against the circular valve seat by spring means (116) adapted to keep the aperture closed until fluid pressure in the inlet chamber exceeds a preselected popping pressure and adapted to open the aperture when the popping pressure is exceeded so as to vent fluid through the aperture into the outlet chamber. An incremental magnetic adjustment (140, 142) means increases or decreases the amount of the bias in finite increments in response to pulses of applied magnetic field so as thereby to increase or decrease the popping pressure in finite increments. The incremental magnetic adjusting means cooperates with the spring means so as to increase or decrease its bias.