Plural valve three stage pressure relief system

An intracranial pressure regulator valve for controlling thc transfer of cerebrospinal fluid from a first location within the body to a second location, said valve comprising:

• catheter means for removing a fluid from said first body location;
• drain means for discharging said fluid to said second location;
• a first fluid flow chamber, said first chamber having a first valve means for regulating fluid flow through said first chamber whereby said first valve means opens at a first predetermined pressure;
• fluid flow restrictor means associated with said first fluid flow chamber for resisting sudden increases in flow rate through said valve;
• a second fluid flow chamber, said second chamber having a second valve means for regulating fluid flow through said second chamber whereby said second valve means opens at a second predetermined pressure, said second predetermined pressure being greater than said first predetermined pressure;
• inlet conduit means for directing said fluid from said catheter means to said first and second chambers whereby said first and second chambers are arranged in parallel fluid flow relation;
• and outlet conduit means for directing said fluid from said first and second chambers to said drain means.

An intracranial pressure regulator valve for controlling the transfer of cerebrospinal fluid from a first location within the body to a second location, said valve comprising:

• a catheter for removing a fluid from said first body location;
• drain means for discharging said fluid to said second location;
• a first fluid flow chamber, said first chamber having a first valve means therein for regulating fluid flow through said first chamber whereby said first valve means opens at a first predetermined pressure differential between said first and second locations, an inlet opening for introducing said fluid into said first chamber and a discharge opening for discharging said fluid from said first chamber;
• a second fluid flow chamber, said second chamber having a second valve means therein for regulating fluid flow through said second chamber whereby said second valve means opens at a second predetermined pressure differential between said first and second locations, said second predetermined pressure differential being greater than said first predetermined pressure differential, an inlet opening for introducing said fluid into said second chamber and a discharge opening for discharging said fluid from said second chamber;
• inlet conduit means for directing said fluid from said catheter means to said first and second flow chambers whereby said first and second chambers are arranged in parallel fluid flow relation;
• outlet conduit means for directing said fluid from said first and second chanbers to said drain means;
• fluid flow restrictor means associated with said first fluid flow chamber for resisting sudden increases in flow rate through said valve wherein said restrictor means and said first fluid flow chamber are arranged in series fluid flow relation;
• and
• whereby said regulator valve operates in a first condition in which fluid flow between said first and second locations is prevented, a second condition in which fluid flow through said regulator valve is sufficient to maintain a first substantially constant predetermined pressure differential between said first location and said second location, a third condition in which fluid flow is at a substantially constant rate through said regulator valve, and a fourth condition in which fluid flow through said regulator valve is sufficient to maintain a second substantially constant predetermined pressure differential between said first location and said second location, wherein said second substantially constant predetermined pressure differential is greater than said first substantially constant predetermined pressure differential.