Intravascular circulatory assist device

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• first and second lumens formed within said catheter for passage of a control fluid;
• at least one fluid flow device connected in flow communication with said first and second lumens, for moving control fluid through said lumens;
• an expandable inner balloon attached to said catheter, said inner balloon being disposable in the vascular system of the patient, with said catheter;
• an expandable outer balloon attached to said catheter, said outer balloon substantially surrounding said inner balloon;
• a first control space between said outer balloon and said inner balloon, said first control space being in fluid flow communication with said first lumen;
• an expandable protective balloon attached to said catheter, said protective balloon substantially surrounding said inner and outer balloons;
• a second control space between said protective balloon and said outer balloon, said second control space being in fluid flow communication with said second lumen;
• an expandable stent disposed near said outer balloon, said expandable stent being selectively expandable from a smaller diameter to a larger diameter by application of control fluid pressure to said first control space, said stent being capable of retaining said larger diameter upon release of said fluid pressure in said first control space, to hold said outer balloon at said larger diameter, said stent being selectively contractible from said larger diameter to said smaller diameter by application of control fluid pressure to said second control space;
• and
• at least one port in said inner balloon, said at least one port being exposable to vascular fluid, for allowing flow of vascular fluid into said inner balloon when said inner balloon expands, and for allowing flow of vascular fluid out of said inner balloon when said inner balloon collapses;
• wherein, after expansion of said stent, said fluid flow device is capable of selectively evacuating control fluid from said first control space to cause said inner balloon to expand, and said fluid flow device is capable of selectively introducing control fluid into said first control space to cause said inner balloon to collapse.

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• a lumen formed within said catheter for passage of a control fluid;
• a fluid flow device connected in flow communication with said lumen, for moving control fluid through said lumen;
• an expandable inner balloon attached to said catheter, said inner balloon being disposable in the vascular system of the patient, with said catheter;
• an expandable outer balloon attached to said catheter, said outer balloon substantially surrounding said inner balloon;
• a control space between said outer balloon and said inner balloon, said control space being in fluid flow communication with said lumen;
• an expandable stent disposed near said outer balloon, said expandable stent being formed of a temperature actuated shape transition material, said expandable stent thereby being selectively expandable from a smaller diameter to a larger diameter by exposure to a first temperature, to hold said outer balloon at said larger diameter, said stent thereby being selectively contractible from said larger diameter to said smaller diameter by exposure to a second temperature;
• and
• at least one port in said inner balloon, said at least one port being exposable to vascular fluid, for allowing flow of vascular fluid into said inner balloon when said inner balloon expands, and for allowing flow of vascular fluid out of said inner balloon when said inner balloon collapses;
• wherein, after expansion of said stent, selectively evacuating control fluid from said control space with said fluid flow device causes said inner balloon to expand, and selectively introducing control fluid into said control space with said fluid flow device causes said inner balloon to collapse.

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• a lumen formed within said catheter for passage of a control fluid;
• a fluid flow device connected in flow communication with said lumen, for moving control fluid through said lumen;
• an expandable inner balloon attached to said catheter, said inner balloon being disposable in the vascular system of the patient, with said catheter;
• an expandable outer balloon attached to said catheter, said outer balloon substantially surrounding said inner balloon;
• a control space between said outer balloon and said inner balloon, said control space being in fluid flow communication with said lumen;
• a self-expanding mechanism retainable in a retention cavity near said outer balloon, said self-expanding mechanism being selectively expandable from a smaller diameter to a larger diameter by release from said retention cavity, to hold said outer balloon at said larger diameter, said self-expanding mechanism being selectively contractible from said larger diameter to said smaller diameter by withdrawal into said retention cavity;
• and
• at least one port in said inner balloon, said at least one port being exposable to vascular fluid, for allowing flow of vascular fluid into said inner balloon when said inner balloon expands, and for allowing flow of vascular fluid out of said inner balloon when said inner balloon collapses;
• wherein, after expansion of said self-expanding mechanism, said fluid flow device is capable of selectively evacuating control fluid from said control space to cause said inner balloon to expand, and said fluid flow device is capable of selectively introducing control fluid into said control space to cause said inner balloon to collapse.

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• a lumen formed within said catheter for passage of a control fluid;
• a fluid flow device connected in flow communication with said lumen, for moving control fluid through said lumen;
• an expandable inner balloon attached to said catheter, said inner balloon being disposable in the vascular system of the patient, with said catheter;
• an expandable outer balloon attached to said catheter, said outer balloon substantially surrounding said inner balloon;
• a control space between said outer balloon and said inner balloon, said control space being in fluid flow communication with said lumen;
• a helical spring near said outer balloon, said spring having a smaller diameter at a relatively longer length, and said spring having a larger diameter at a relatively shorter length, to hold said outer balloon at said larger diameter;
• and
• at least one port in said inner balloon, said at least one port being exposable to vascular fluid, for allowing flow of vascular fluid into said inner balloon when said inner balloon expands, and for allowing flow of vascular fluid out of said inner balloon when said inner balloon collapses;
• wherein, after transformation of said helical spring to said larger diameter, selectively evacuating control fluid from said control space with said fluid flow device causes said inner balloon to expand, and selectively introducing control fluid into said control space with said fluid flow device causes said inner balloon to collapse.

A method of assisting circulation of a vascular fluid, comprising:

• providing a catheter mounted circulation device having an inner balloon and an outer balloon, with a control space between said inner and outer balloons, said circulation device also having an expansion mechanism for mechanically holding said outer balloon in an expanded state, said circulation device having at least one port leading into the interior of said inner balloon;
• inserting said circulation device through a vascular system of a patient, to a desired location where said at least one port of said inner balloon is exposed to vascular fluid;
• expanding said outer balloon and said expansion mechanism;
• holding said outer balloon in said expanded state with said expansion mechanism;
• introducing a control fluid into said control space to collapse said inner balloon, thereby expelling vascular fluid from said at least one port;
• and
• evacuating control fluid from said control space to expand said inner balloon, thereby drawing vascular fluid into said interior of said inner balloon.

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• a selectively expandable inner membrane attached to said catheter, said inner membrane being disposable in the vascular system of the patient, with said catheter;
• a selectively expandable outer membrane attached to said catheter, said outer membrane substantially surrounding said inner membrane;
• a retention means for retaining said outer membrane in an expanded state;
• a two-way control fluid flow device connected in flow communication with a control space adjacent said inner membrane, whereby selective introduction of a control fluid into, and removal of a control fluid from, said control space, with said control fluid flow device, causes said inner membrane to expand and collapse;
• a pumping chamber within at least said outer membrane;
• and
• at least one port into said pumping chamber, said port being exposable to vascular fluid, said port being capable of allowing flow of vascular fluid into, and allowing flow of vascular fluid out of, said pumping chamber, when said inner membrane expands and collapses.

A circulatory assist device, comprising:

• a flexible tubular catheter, said catheter being sized for insertion into a vascular system of a patient;
• a selectively expandable inner membrane attached to said catheter, said inner membrane being disposable in the vascular system of the patient, with said catheter;
• a selectively expandable outer membrane attached to said catheter, said outer membrane substantially surrounding said inner membrane:
• a retention means for retaining said outer membrane in an expanded state;
• a two-way control fluid flow device connected in flow communication with a control space adjacent said inner membrane, whereby selective introduction of a control fluid into, and removal of a control fluid from, said control space, with said control fluid flow device, causes said inner membrane to expand and collapse;
• a pumping chamber within at least said outer membrane;
• and
• at least one port into said pumping chamber, said port being exposable to vascular fluid, said port being capable of allowing flow of vascular fluid into, and allowing flow of vascular fluid out of, said pumping chamber, when said inner membrane expands and collapses;
• wherein:
• said pumping chamber is within said inner membrane;
• said control space is between said inner membrane and said outer membrane, causing said inner membrane to collapse upon introduction of said control fluid into said control space, and causing said inner membrane to expand upon removal of said control fluid from said control space;
• and
• said port is in said inner membrane, to allow flow of vascular fluid into and out of said pumping chamber within said inner membrane, as said inner membrane expands and collapses.

A method of assisting circulation of a vascular fluid, comprising:

• providing a catheter mounted circulation device having an inner membrane and an outer membrane, with a control space adjacent said inner membrane, said outer membrane also being mechanically fixable in an expanded state, said circulation device having at least one vascular fluid flow port;
• inserting said circulation device through a vascular system of a patient, to a desired location where said at least one vascular fluid flow port is exposed to vascular fluid;
• expanding said outer membrane;
• holding said outer membrane in said expanded state;
• alternatingly introducing a control fluid into said control space and evacuating control fluid from said control space to alternatingly expand and collapse said inner membrane, thereby drawing vascular fluid into, and expelling vascular fluid from, said circulation device.