Gradient sequential compression system for preventing deep vein thrombosis

A sequential compression device for improving venous blood flow in a limb of a user by applying sequentially established compressive forces to the limb through means of at least first and second inflatable chambers during an inflation cycle, comprising:

• a housing;
• a first filling valve in said housing and pneumatically connectable at an output thereof to the first inflatable chamber, said first filling valve having an open state for enabling transfer of pressurized air from a source to the first inflatable chamber and a closed blocking state;
• a first monitoring valve in said housing and pneumatically connectable at an input thereof to the first inflatable chamber, said first monitoring valve having an open state for enabling the release of pressurized air from the first inflatable chamber and a closed blocking state, wherein in said open state said first monitoring valve enables the transfer of pressurized air from the first inflatable chamber to an output of the first monitoring valve such that the pressure of the air in the first inflatable chamber may be monitored by monitoring the output of the first monitoring valve;
• a second filling valve in said housing and pneumatically connectable at an output thereof to the second inflatable chamber, said second filling valve having an open state for enabling transfer of pressurized air from the source to the second inflatable chamber and a closed blocking state;
• a second monitoring valve in said housing and pneumatically connectable at an input thereof to the second inflatable chamber, said second monitoring valve having an open state for enabling the release of pressurized air from the second inflatable chamber and a closed blocking state, wherein in said open state said second monitoring valve enables the transfer of pressurized air from the second inflatable chamber to an output of the second monitoring valve such that the pressure of the air in the second inflatable chamber may be monitored by monitoring the output of the second monitoring valve;
• and
• control means, operatively connected to said first and second filling and monitoring valves, wherein said control means inflates said first inflatable chamber from a deflated condition to a first predetermined chamber pressure in a first interval by disposing the first filling valve in its respective open state and the second filling valve in its respective closed state during the first inflation time interval within the inflation cycle, wherein said control means in response to said first inflatable chamber reaching the first predetermined chamber pressure, inflates said second inflatable chamber from a deflated condition to a second predetermined pressure in a second time interval by disposing the second filling valve in its respective open state and the first filling valve in its respective closed state during the second inflation time interval within the inflation cycle, and wherein said control means separately measures the pressure in said first and second inflatable chambers.