Cardiac assist pump with steady rate supply of fluid lubricant
First Claim
1. A system for conveying bodily fluid including:
- a pump having a housing defining a first chamber, a second chamber, a first inlet passageway in fluid communication with said first chamber for admitting a bodily fluid into said first chamber, a first outlet passageway in fluid communication with said first chamber for expelling said bodily fluid out of the first chamber, and a second inlet passageway in fluid communication with said second chamber for admitting a fluid lubricant into the second chamber, said lubricant being biocompatible and soluble in said bodily fluid;
an impeller mounted rotatably in said first chamber, a rotor mounted to rotate in said second chamber, and a connecting means for coupling said impeller to rotate responsive to rotation of said rotor;
an elastically deformable sealing means fixed to said housing, disposed between said first chamber and said second chamber, and forming an interface with said connecting means, said sealing means normally in a surface engagement with said connecting means along said interface;
a supply means for supplying said lubricant at a first predetermined constant fluid flow rate through the second inlet passageway into said second chamber, to cause a perfusion of said lubricant along said interface and into said first chamber at a second constant fluid flow rate, thus to elastically deform said sealing means and maintain said sealing means in close, spaced apart relation to said connecting means against a restoring force in said sealing means tending to restore said surface engagement, so long as said perfusion continues; and
a drive means for rotating said rotor to convey said bodily fluid through said first chamber and said first inlet and outlet passageways.
2 Assignments
0 Petitions
Accused Products
Abstract
A centrifugal pump for left ventricle assist includes a pump housing forming an impeller chamber with inlet and outlet passages and enclosing an impeller rotatable to move blood through the impeller chamber, and a rotor chamber enclosing a rotor integral with the impeller and rotatable to drive the impeller. An elastically deformable seal member separates the rotor and impeller chambers, and includes an annular lip seal surrounding a shaft which joins the impeller and rotor. A saline solution is supplied at a constant fluid flow rate to the rotor chamber through an inlet passage, and leaves the rotor chamber by perfusing into the impeller chamber along the interface between the shaft and lip seal. The saline solution thus provides hydrodynamic bearings between the rotating shaft and rotor, and the fixed pump housing and lip seal, and further prevents blood in the impeller chamber from entering the rotor chamber. The lip seal is configured to encourage flow of saline solution along the lip seal/impeller shaft interface, while resisting the flow of blood along the interface.
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Citations
21 Claims
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1. A system for conveying bodily fluid including:
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a pump having a housing defining a first chamber, a second chamber, a first inlet passageway in fluid communication with said first chamber for admitting a bodily fluid into said first chamber, a first outlet passageway in fluid communication with said first chamber for expelling said bodily fluid out of the first chamber, and a second inlet passageway in fluid communication with said second chamber for admitting a fluid lubricant into the second chamber, said lubricant being biocompatible and soluble in said bodily fluid; an impeller mounted rotatably in said first chamber, a rotor mounted to rotate in said second chamber, and a connecting means for coupling said impeller to rotate responsive to rotation of said rotor; an elastically deformable sealing means fixed to said housing, disposed between said first chamber and said second chamber, and forming an interface with said connecting means, said sealing means normally in a surface engagement with said connecting means along said interface; a supply means for supplying said lubricant at a first predetermined constant fluid flow rate through the second inlet passageway into said second chamber, to cause a perfusion of said lubricant along said interface and into said first chamber at a second constant fluid flow rate, thus to elastically deform said sealing means and maintain said sealing means in close, spaced apart relation to said connecting means against a restoring force in said sealing means tending to restore said surface engagement, so long as said perfusion continues; and a drive means for rotating said rotor to convey said bodily fluid through said first chamber and said first inlet and outlet passageways. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification