Magnetically-adjustable cerebrospinal fluid shunt valve
First Claim
1. A surgically-implantable shunt valve for venting cerebrospinal fluid in the treatment of hydrocephalus and for shunting other body fluids, said valve comprisinga housing constructed of a surgically-implantable material,an inlet and outlet chamber within said housing,said housing including inlet and outlet ports communicating with said inlet and outlet chambers respectively for connecting said inlet and outlet chambers to external catheters or other fluid conduits,an aperture communicating between said chambers, said aperture having a circular periphery forming a circular valve seat,a valve element of diameter larger than said circular valve seat,spring means for biasing said valve element against the circular valve seat so as to keep said aperture closed until the cerebrospinal fluid pressure in said inlet chamber exceeds a preselected popping pressure and so as to open said aperture when said popping pressure is exceeded so as to vent cerebrospinal fluid through said aperture into said outlet chamber, andincremental magnetic adjustment means for increasing or decreasing the amount of said bias in finite increments in response to pulses of a magnetic field applied from outside the body ao as thereby to increase or decrease said popping pressure in finite increments, said incremental magnetic adjustment means comprisinga primary member adapted to cooperate with said spring means so as to increase or decrease said bias when said primary member is moved, said primary member not being itself susceptible to movement by said external magnetic field, anda secondary member susceptible to said applied magnetic field and mounted and positioned with respect to said primary member so as to be capable of movement relative to said primary member and so as to cause no more than an incremetal movement of said primary member for each pulse of said magnetic field.
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Accused Products
Abstract
A surgically-implantable shunt valve in which the popping pressure is adjusted in finite increments by application of an external magnetic field.
258 Citations
33 Claims
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1. A surgically-implantable shunt valve for venting cerebrospinal fluid in the treatment of hydrocephalus and for shunting other body fluids, said valve comprising
a housing constructed of a surgically-implantable material, an inlet and outlet chamber within said housing, said housing including inlet and outlet ports communicating with said inlet and outlet chambers respectively for connecting said inlet and outlet chambers to external catheters or other fluid conduits, an aperture communicating between said chambers, said aperture having a circular periphery forming a circular valve seat, a valve element of diameter larger than said circular valve seat, spring means for biasing said valve element against the circular valve seat so as to keep said aperture closed until the cerebrospinal fluid pressure in said inlet chamber exceeds a preselected popping pressure and so as to open said aperture when said popping pressure is exceeded so as to vent cerebrospinal fluid through said aperture into said outlet chamber, and incremental magnetic adjustment means for increasing or decreasing the amount of said bias in finite increments in response to pulses of a magnetic field applied from outside the body ao as thereby to increase or decrease said popping pressure in finite increments, said incremental magnetic adjustment means comprising a primary member adapted to cooperate with said spring means so as to increase or decrease said bias when said primary member is moved, said primary member not being itself susceptible to movement by said external magnetic field, and a secondary member susceptible to said applied magnetic field and mounted and positioned with respect to said primary member so as to be capable of movement relative to said primary member and so as to cause no more than an incremetal movement of said primary member for each pulse of said magnetic field.
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33. A surgically-implantable shunt valve for venting cerebrospinal fluid in the treatment of hydrocephalus and for shunting other body fluids, said valve comprising
a housing constructed of a surgically-implantable material, an inlet and outlet chamber within said housing, said housing including inlet and outlet ports communicating with said inlet and outlet chambers respectively for connecting said inlet and outlet chambers to external catheters or other fluid conduits, an aperture communicating between said chambers, said aperture having a circular periphery forming a circular valve seat, a valve element of diameter larger than said circular valve seat, spring means for biasing said valve element against the circular valve seat so as to keep said aperture closed until the cerebrospinal fluid pressure in said inlet chamber exceeds a preselected popping pressure and so as to open said aperture when said popping pressure is exceeded so as to vent cerebrospinal fluid through said aperture into said outlet chamber, and incremental magnetic adjustment means for increasing or decreasing the amount of said bias in finite increments in response to pulses of an applied magnetic field so as thereby to increase or decrease said popping pressure in finite increments, said incremental magnetic adjustment means comprising an element adapted to rotate in response to an external magnetic field and wherein said valve further comprises a cam in the shape of a circular staircase and wherein said spring means includes one arm supported on said staircase.
Specification