Ventricular shunt having a variable pressure valve

Claim 2

A cerebral-spinal fluid shunt system comprising: a conduit for venting fluid from a patient''s cerebral-spinal fluid system; a conduit for draining cerebral-spinal fluid into a selected drainage site within the patient''s body; means for sensing the force exerted by the brain in the dural region; a one-way bypass valve connecting said vent conduit and said drain conduit, said bypass valve including biasing means for maintaining a pressure differential between said vent conduit and said drain conduit; and means interconnected with said biasing means responsive to said sensing means for adjusting the biasing of said bypass valve as a function of the sensed force thereby to maintain said force substantially at the desired level.

Claim 3

A cerebral-spinal fluid shunt system comprising: a conduit for venting fluid from a patient''s cerebral-spinal fluid system; a conduit for draining cerebral-spinal fluid into a selected drainage site within the patient''s body; means for sensing the force exerted by the brain in the dural region; a one-way bypass valve connecting said vent conduit and said drain conduit, said bypass valve including biasing means for maintaining a pressure differential between said vent conduit and said drain conduit; and means interconnected with said biasing means responsive to said sensing means for adjusting the biasing of said bypass valve as a function of the sensed force thereby to maintain said force substantially at the desired level.

Claim 4

A cerebral-spinal fluid shunt system comprising: a conduit for venting fluid from a patient''s cerebral-spinal fluid system; a conduit for draining cerebral-spinal fluid into a selected drainage site within the patient''s body; means for sensing the force exerted by the brain in the dural region; a one-way bypass valve connecting said vent conduit and said drain conduit, said bypass valve including biasing means for maintaining a pressure differential between said vent conduit and said drain conduit; and means interconnected with said biasing means responsive to said sensing means for adjusting the biasing of said bypass valve as a function of the sensed force thereby to maintain said force substantially at the desired level.

Claim 5

The improvement defined by claim 1 wherein the biasing means comprises a spring mounted to a movable base with means for adjustably moving said base.

Claim 6

The improvement defined by claim 1 wherein the means for controlling the biasing means includes hydraulically interconnected sensor bladder and control bladder, the sensor bladder being adapted to contact the brain directly or through its enveloping membranes and the control bladder being operatively associated with the biasing means thereby to vary the biasing force exerted by the biasing means.

Claim 7

A cerebral-spinal fluid shunt valve comprising a conduit member having an inlet and an outlet, a valve body within said conduit member having a passageway between said inlet and outlet terminating in a valve seat, a valve member overlying said seat and forming a one-way closure to said passageway, resilient means movably mounted relative to said valve body biasing said valve member against said seat thereby to maintain a preselected back pressure in the ventricle, force responsive means outside said conduit adapted to contact brain in the epi- or sub- dural region, and movable means responsive to said force responsive means and operatively interconnected with said resilient biasing means to increase the bias thereof as the force decreases and vice versa thereby to maintain said force at a preselected level.

Claim 8

A cerebral-spinal fluid shunt valve comprising a conduit member having an inlet and an outlet, a valve body within said conduit member having a passageway between said inlet and outlet terminating in a valve seat, a valve member overlying said seat and forming a one-way closure to said passageway, resilient means movably mounted relative to said valve body biasing said valve member against said seat thereby to maintain a preselected back pressure in the ventricle, force responsive means outside said conduit adapted to contact brain in the epi- or sub- dural region, and movable means responsive to said force responsive means and operatively interconnected with said resilient biasing means to increase the bias thereof as the force decreases and vice versa thereby to maintain said force at a preselected level.

Claim 9

The cerebral-spinal fluid shunt valve defined by claim 4 wherein the force responsive means and movable means comprise hydraulically connected bladders including a sensing bladder adapted to be inserted into the dural region and a control bladder operatively associated with the resilient means thereby to vary the biasing force exerted by the biasing member.

Claim 10

A cerebral-spinal fluid shunt valve comprising a conduit member having an inlet and an outlet, a valve within said conduit including resilient means biasing the valve closed, and an hydraulic servo mechanism comprising a sensing bladder adapted to contact the brain in the dural region and a control bladder in said valve operatively associated with said resilient means opposing said biasing, said sensing bladder and control bladder being hydraulically interconnected.

Claim 11

A cerebral-spinal fluid shunt valve comprising a conduit member having an inlet and an outlet, a valve within said conduit including resilient means biasing the valve closed, and an hydraulic servo mechanism comprising a sensing bladder adapted to contact the brain in the dural region and a control bladder in said valve operatively associated with said resilient means opposing said biasing, said sensing bladder and control bladder being hydraulically interconnected.

Claim 12

The valve defined by claim 6 wherein the hydraulic interconnection comprises a radiopaque fluid.