Blood pump and method of pumping blood
First Claim
1. A blood pump comprising a case defining a pumping cavity, inlet and outlet passages leading into the cavity;
- a thin walled pumping sac comprising a pumping chamber positioned freely within the cavity and integral inlet and outlet ports positioned within the inlet and outlet passages, the chamber including first and second parts and an equator joining the parts with the outlet port formed in the first part adjacent the equator;
inlet and outlet valves on the case at the ends of the inlet and outlet passages connected in a fluid flow relation to said inlet and outlet ports for controlling the flow of blood through the pump;
means for alternately expanding and collapsing the second part of the chamber to pump blood past the valves, a portion of the pumping sac adjacent to the outlet port having a greater resistance to flexing than the remainder of the chamber, said portion extending across the equator and overlying the outlet port, whereby during pumping of blood from the chamber the portion collapses subsequent to collapse of the remainder of the chamber.
2 Assignments
0 Petitions
Accused Products
Abstract
A blood pump for implant or paracorporeal use having a rigid case with inlet and outlet valves defining a pumping cavity; an integral thin walled flexible sac freely confined within a pumping cavity; and a flexible diaphragm within the cavity conforming to the shape of the adjacent side of the sac. The case includes a control ring projecting into the cavity between the diaphragm and sac. The diaphragm is moved between diastolic and systolic positions to pump blood through the valves. During pumping, the ring distributes flexing of the diaphragm over an increased area while also preventing the interior walls of the sac from contacting each other. The outlet port and the portion of the sac immediately surrounding the outlet port are less flexible than the remainder of the sac away from the port and the portion of the diaphragm overlying the outlet port is less flexible than the remainder of the diaphragm. The less flexible portions of the sac and diaphragm improve pressure pulse pumping so that the more flexible portion of the sac away from the outlet port is initially collapsed and the sac is progressively collapsed from that portion to the outlet port to minimize stasis in the pumping chamber. The less flexible portion of the sac also prevents collapse at the port due to the decreased Venturi effect pressure during the systolic stroke.
140 Citations
43 Claims
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1. A blood pump comprising a case defining a pumping cavity, inlet and outlet passages leading into the cavity;
- a thin walled pumping sac comprising a pumping chamber positioned freely within the cavity and integral inlet and outlet ports positioned within the inlet and outlet passages, the chamber including first and second parts and an equator joining the parts with the outlet port formed in the first part adjacent the equator;
inlet and outlet valves on the case at the ends of the inlet and outlet passages connected in a fluid flow relation to said inlet and outlet ports for controlling the flow of blood through the pump;
means for alternately expanding and collapsing the second part of the chamber to pump blood past the valves, a portion of the pumping sac adjacent to the outlet port having a greater resistance to flexing than the remainder of the chamber, said portion extending across the equator and overlying the outlet port, whereby during pumping of blood from the chamber the portion collapses subsequent to collapse of the remainder of the chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a thin walled pumping sac comprising a pumping chamber positioned freely within the cavity and integral inlet and outlet ports positioned within the inlet and outlet passages, the chamber including first and second parts and an equator joining the parts with the outlet port formed in the first part adjacent the equator;
- 10. A blood pump comprising a case defining a pumping cavity with inlet and outlet passages, a thin walled pumping sac freely positioned within the case with a pumping chamber in the pumping cavity and inlet and outlet ports in the inlet and outlet passages, inlet and outlet valves at the ends of the passages in fluid flow communication with the inlet and outlet ports, the pumping chamber having two like sides separated by an equator, said inlet and outlet ports being located adjacent to each other and close to and on one side of the equator, means for flexing a first side of the pumping chamber away from the inlet and outlet ports between extended and collapsed positions about a smooth generally equatorial flex line to pump blood into and out ot the sac, and means within the cavity for preventing the interior surfaces of the sides from touching each other when the chamber is collapsed.
- 17. A blood pump comprising a case defining a pumping cavity, inlet and outlet passages leading into the cavity, a thin walled pumping sac comprising a pumping chamber positioned freely within the cavity with integral inlet and outlet ports positioned within the inlet and outlet passages, inlet and outlet valves on the case at the ends of the inlet and outlet passages connected in fluid flow relation to said inlet and outlet ports for control flowing of blood through the pump, the pumping chamber having an equator separating first and second like sides with the inlet and outlet ports joining the second side, a diaphragm generally conforming in shape to the first side attached to the case and extending across the cavity, said diaphragm engaging the outer surface of said first side to form a unitary pumping wall, a control ring projecting into the cavity and extending around the cavity between the equator of the chamber and the diaphragm, and means for moving the pumping wall back and forth to expand and collapse the pumping chamber and pump blood past the valves, whereby upon collapse of the pumping wall the control ring prevents the interior surfaces of the chamber sides from touching each other.
- 23. An improved blood pumping sac adapted to be positioned freely within the case of a blood pump, said sac being formed of a thin, flexible and appendage free material with a hemocompatible inner surface, the sac comprising a pumping chamber with an equator, two like sides separated by the equator, and integral inlet and outlet ports in one side, the outlet port being located adjacent the equator, the sac including a less flexible portion surrounding the outlet port, extending across the equator to the other side and overlying the outlet port to resist premature collapse during pumping of blood from the chamber.
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29. A blood pump comprising a case defining a pumping cavity and inlet and outlet passages leading into the cavity;
- a thin-walled pumping sac comprising a pumping chamber positioned freely within the cavity with integral inlet and outlet ports positioned within the inlet and outlet passages, the pumping chamber, when expanded, having an equator separating a pair of like chamber sides, said inlet and outlet ports being located on one of the chamber sides;
a control ring unitary with the case extending around the periphery of the pumping cavity on the side of the equator away from the inlet and outlet passages;
a pumping diaphragm attached to the case adjacent to the side of the control ring away from the equator and generally conforming to the shape of and lying on the adjacent chamber side of the pumping chamber to form a flexible pumping wall;
inlet and outlet valves on the case at the ends of inlet and outlet passages connected in fluid flow relation to said inlet and outlet ports for controlling the flow of blood through the pump; and
means for introducing pulses into the space between the diaphragm and adjacent wall of the cavity away from the chamber so that the diaphragm and adjacent side of the chamber move together between expanded and collapsed positions of the chamber with the diaphragm flexed over the inner edge of the ring when the chamber is collapsed and being flexed about its attachment to the case when the chamber is expanded.
- a thin-walled pumping sac comprising a pumping chamber positioned freely within the cavity with integral inlet and outlet ports positioned within the inlet and outlet passages, the pumping chamber, when expanded, having an equator separating a pair of like chamber sides, said inlet and outlet ports being located on one of the chamber sides;
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30. A blood pump comprising a case defining a pumping cavity having a cavity equator separating a pair of generally like cavity sides, inlet and outlet passages leading into the cavity, said passages being located on one side of the cavity equator;
- a thin-walled pumping sac comprising a pumping chamber positioned freely within the cavity with integral inlet and outlet ports positioned within the inlet and outlet passages, said sac having an equator substantially coincident with the cavity equator;
inlet and outlet valves on the case at the ends of the inlet and outlet ports for controlling the flow of blood through the pump;
the case including a control member extending into the pumping cavity on the other side of the cavity equator and extending at least partially along such equator;
a pumping diaphragm attached to the case on the other side of the cavity equator with the control member located between the diaphragm and the cavity equator, the diaphragm generally conforming in shape to the shape of and lying on the adjacent side of the pumping chamber to form a flexible pumping wall; and
means adaptable for moving the pumping wall between expanded and collapsed positions of the chamber with the diaphragm being flexed over the inner edge of the control member when the chamber is collapsed and being flexed about its attachment to the case when the chamber is expanded. - View Dependent Claims (31, 32)
- a thin-walled pumping sac comprising a pumping chamber positioned freely within the cavity with integral inlet and outlet ports positioned within the inlet and outlet passages, said sac having an equator substantially coincident with the cavity equator;
- 33. An improved pumping diaphragm for use in blood pump, said diaphragm including a thin domed flexible wall adapted to be moved between extended and retracted positions, and means on the periphery of the wall for attaching the diaphragm to the case of a blood pump, said wall including a peripheral portion having greater resistance to flexing than the remainder of the wall.
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36. The method of pumping blood using a collapsible sac having a thin walled flexible pumping side and a nonmoving side with inlet and outlet ports extending from the nonmoving side and with the outlet port located adjacent to the edge of the pumping side, comprising the steps of:
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A. Expanding the sac to fill the sac with blood flowing through the inlet port by moving the pumping side away from the nonmoving side; and
thenB. Collapsing the sac to pump blood out the outlet port without obstruction by moving the portion of the pumping side remote from the outlet port toward the nonmoving side faster than the portion of the pumping side overlying the outlet port is moved toward the nonmoving side and completing collapse of the pumping side remote from the outlet port prior to restriction of the outlet port by collapse of the portion of the pumping side overlying the outlet port. - View Dependent Claims (37, 38, 39, 40)
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41. The method of pumping blood using a pump having a flexible pumping chamber and a flexible diaphragm peripherally secured to the pump overlying one side of the chamber, comprising the steps of:
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A. Moving the diaphragm through a diastolic stroke to expand and fill the chamber; B. Moving the diaphragm through a systolic stroke to collapse and empty the chamber; and C. During each diastolic and systolic stroke successively flexing the diaphragm at its periphery about each of a pair of spaced peripheral flex areas. - View Dependent Claims (42, 43)
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Specification