Method and apparatus for cardiac blood flow assistance

Claim 2

An intravascular microaxial flow pump, comprising: a cylindrical drive unit of preselected outer diameter having an electric motor disposed therein driving a shaft distally extending therefrom wherein such shaft is supported solely by two bearings, one located at the extreme proximal end of said drive unit and another at the extreme distal end of said drive unit; a cylindrical intravascular microaxial flow pump housing rigidly attached to said drive unit having essentially the same preselected outer diameter and oriented to be coaxially and distally disposed with respect to said drive unit; and an impeller disposed within said pump housing, rigidly affixed to said shaft, and located immediately adjacent said distal bearing, operative to draw fluid into and through said housing and over said drive unit.

Claim 3

The pump of claim 1 further comprising a catheter proximally extending from said drive unit to facilitate transport of said pump through vasculature by manipulation of the proximal end of said catheter.

Claim 4

The pump of claim 2 further comprising conductors disposed in said catheter and connected to said electric motor by which said electric motor is powered and the operation of said motor is controlled.

Claim 5

The pump of claim 1, wherein said pump housing is attached to said drive unit exclusively by radially extending pump stator elements disposed proximally relative to said impeller.

Claim 6

The pump of claim 1, wherein said pump housing is attached to said drive unit by support members that are configured and positioned to minimize interference with fluid flowing thereby and wherein said pump is devoid of a fixed pump stator.

Claim 7

The pump of claim 1, wherein said distal bearing simultaneously serves as a seal.

Claim 8

The pump of claim 6, wherein said distal bearing comprises an annular cup configuration having a distally oriented open end.

Claim 9

The pump of claim 6 further comprising a secondary seal disposed proximally to said distal bearing.

Claim 10

The pump of claim 8, wherein an annular void space is formed in said drive unit, extending about said shaft between said distal bearing and said secondary seal.

Claim 11

The pump of claim 9, wherein said annular void contains a biocompatible lubricant.

Claim 12

The pump of claim 1, wherein said drive unit is charged with a fluid at a pressure less than that of fluid to be pumped by said fluid pump.

Claim 13

The pump of claim 11, wherein said fluid is chemically inert.

Claim 14

The pump of claim 12, wherein said fluid comprises a gas.

Claim 15

The pump of claim 13, wherein said gas comprises He.

Claim 16

The pump of claim 1, wherein said drive unit is charged with a fluid at a pressure that exceeds the pressure of fluid to be pumped by said fluid pump.

Claim 17

The pump of claim 15, wherein said fluid is biocompatible.

Claim 18

The pump of claim 16, wherein said fluid is chemically inert.

Claim 19

The pump of claim 15, wherein said fluid is chemically inert.

Claim 20

The pump of claim 15, wherein said fluid comprises a gas.

Claim 21

The pump of claim 15 further comprising a flexible diaphragm disposed on said drive unit's exterior surface and in fluid communication with said internal void space, configured such that a positive internal pressure of said fluid imparts a domed appearance to said diaphragm to provide a visual indication as to the state of charge.

Claim 22

The pump of claim 15, wherein said charge pressure is selected to cause said fluid to slowly and continually discharge from said drive unit.

Claim 23

The pump of claim 21 further comprising a catheter proximally extending from said drive unit and in fluid communication therewith through which said fluid is supplied.

Claim 24

The pump of claim 22, wherein said fluid is biocompatible.

Claim 25

An intravascular microaxial flow pump, comprising: a cylindrical drive unit of preselected outer diameter having an electric motor disposed therein driving a shaft distally extending therefrom wherein void space within said drive unit is separated from its exterior by a seal, fitted about said shaft; a cylindrical pump housing rigidly attached to said drive unit having essentially the same preselected outer diameter and oriented to be coaxially and distally disposed with respect to said drive unit; an impeller disposed within said pump housing, rigidly affixed to said shaft; a biocompatible charge fluid contained within said void space and charged to a pressure that exceeds the pressure of fluid to be pumped by said fluid pump; and, a flexible diaphragm disposed on an exterior surface of said drive unit and in fluid communication with said void space, configured such that a positive internal pressure of said fluid imparts a domed appearance to said diaphragm to provide a visual indication as to the state of charge.

Claim 26

An intravascular microaxial flow pump, comprising: a cylindrical drive unit of preselected outer diameter having an electric motor disposed therein driving a shaft distally extending therefrom wherein void space within said drive unit is separated from its exterior by a seal, fitted about said shaft; a cylindrical pump housing rigidly attached to said drive unit having essentially the same preselected outer diameter and oriented to be coaxially and distally disposed with respect to said drive unit; an impeller disposed within said pump housing, rigidly affixed to said shaft; a biocompatible charge fluid contained within said void space and charged to a pressure that exceeds the pressure of fluid to be pumped by said fluid pump; and, a flexible diaphragm disposed on an exterior surface of said drive unit and in fluid communication with said void space, configured such that a positive internal pressure of said fluid imparts a domed appearance to said diaphragm to provide a visual indication as to the state of charge.

Claim 27

The pump of claim 24, wherein said charge fluid is charged to a pressure that is selected to cause said fluid to slowly and continually breach said seal.

Claim 28

The pump of claim 25 further comprising a catheter proximally extending from said drive unit and in fluid communication with said void space through which said fluid is supplied.

Claim 29

An intravascular microaxial flow pump, comprising: a cylindrical drive unit of preselected outer diameter having an electric motor disposed therein driving a shaft distally extending therefrom wherein such shaft is supported solely by two bearings, one located at the extreme proximal end of said drive unit and another at the extreme distal end of said drive unit; a cylindrical intravascular microaxial flow pump housing rigidly attached to said drive unit having essentially the same preselected outer diameter and oriented to be coaxially and distally disposed with respect to said drive unit; and an impeller disposed within said pump housing, rigidly affixed to said shaft, and located immediately adjacent said distal bearing, operative to draw fluid over said drive unit and through said housing.

Claim 30

An intravascular microaxial flow pump, comprising: a cylindrical drive unit of preselected outer diameter having an electric motor disposed therein driving a shaft distally extending therefrom wherein such shaft is supported solely by two bearings, one located at the extreme proximal end of said drive unit and another at the extreme distal end of said drive unit; a cylindrical intravascular microaxial flow pump housing rigidly attached to said drive unit having essentially the same preselected outer diameter and oriented to be coaxially and distally disposed with respect to said drive unit; and an impeller disposed within said pump housing, rigidly affixed to said shaft, and located immediately adjacent said distal bearing, operative to draw fluid over said drive unit and through said housing.

Claim 31

The pump of claim 27 further comprising a catheter proximally extending from said drive unit to facilitate transport of said pump through vasculature by manipulation of the proximal end of said catheter.

Claim 32

The pump of claim 28 further comprising conductors disposed in said catheter and connected to said electric motor by which said electric motor is powered and the operation of said electric motor is controlled.

Claim 33

The pump of claim 27, wherein said pump housing is attached to said drive unit exclusively by radially extending pump stator elements disposed proximally relative to said impeller.

Claim 34

The pump of claim 27, wherein said pump housing is attached to said drive unit by support members that are configured and positioned to minimize interference with fluid flowing thereby and wherein said pump is devoid of a fixed pump stator.

Claim 35

The pump of claim 27, wherein said distal bearing simultaneously serves as a seal.

Claim 36

The pump of claim 32, wherein said distal bearing comprises an annular cup configuration having a distally oriented open end.

Claim 37

The pump of claim 32 further comprising a secondary seal disposed proximally to said distal bearing.

Claim 38

The pump of claim 34, wherein an annular void space is formed in said drive unit, extending about said shaft between said distal bearing and said secondary seal.

Claim 39

The pump of claim 35, wherein said annular void contains a biocompatible lubricant.

Claim 40

The pump of claim 27, wherein said drive unit is charged with a fluid at a pressure less than that of fluid to be pumped by said fluid pump.

Claim 41

The pump of claim 37, wherein said fluid is chemically inert.

Claim 42

The pump of claim 38, wherein said fluid comprises a gas.

Claim 43

The pump of claim 39, wherein said gas comprises He.

Claim 44

The pump of claim 27, wherein said drive unit is charged with a fluid at a pressure that exceeds the pressure of fluid to be pumped by said fluid pump.

Claim 45

The pump of claim 41, wherein said fluid is biocompatible.

Claim 46

The pump of claim 42, wherein said fluid is chemically inert.

Claim 47

The pump of claim 41, wherein said fluid is chemically inert.

Claim 48

The pump of claim 41, wherein said fluid comprises a gas.

Claim 49

The pump of claim 41 further comprising a flexible diaphragm disposed on said drive unit's exterior surface and in fluid communication with said internal void space, configured such that a positive internal pressure of said fluid imparts a domed appearance to said diaphragm to provide a visual indication as to the state of charge.

Claim 50

The pump of claim 41, wherein said charge pressure is selected to cause said fluid to slowly and continually discharge from said drive unit.

Claim 51

The pump of claim 47 further comprising a catheter proximally extending from said drive unit and in fluid communication therewith through which said fluid is supplied.

Claim 52

The pump of claim 48, wherein said fluid is biocompatible.