Heart pump

1 . A heart pump including:

a) a housing forming a cavity including:

i) at least one inlet aligned with an axis of the cavity;

ii) at least one outlet provided in a circumferential outer wall of the cavity; and,

iii) an outlet volute:

b) an impeller provided within the cavity, the impeller including vanes for urging fluid from the inlet to the outlet; and,

c) a drive for rotating the impeller in the cavity, wherein the outlet volute is configured to generate a maximum radial force of less than 1.2 N over a defined flow range of 5 LPM to 8 LPM.

2 . A pump according to claim 1 , wherein the pump at least one of:

a) has a performance curve having a gradient of less than-20% over the defined flow range such that a change in pressure of 10 mmHg across the pump causes a change in flow rate of at least 2 LPM, the defined flow range being between at least one of:

i) 5 LPM and 8 LPM;

ii) 3 LPM and 12 LPM; and,

iii) 3 LPM and 15 LPM; and,

b) generates a pressure head that is at least one of:

i) for a pump that provides at least partial left ventricular function:

(1) between 60 mmHg and 100 mmHg at 6 LPM;

(2) between 70 mmHg and 90 mmHg at 6 LPM; and,

(3) approximately 80 mmHg at 6 LPM; and,

ii) for a pump that provides at least partial right ventricular function:

(1) between 10 mmHg and 30 mmHg at 6 LPM;

(2) between 15 mmHg and 25 mmHg at 6 LPM; and,

(3) approximately 20 mmHg at 6 LPM.

3 . A heart pump according to claim 1 , wherein the heart pump is configured to provide at least partial left ventricular function.

4 . A heart pump according to claim 3 , wherein at least one of:

a) the heart pump has a pump performance curve having a gradient less than at least one of:

i) −25%;

ii) −30%;

iii) −35%;

iv) −40%;

v) −100%

vi) −200%; or

vii) −500%; or,

b) an axial position of the impeller within the cavity controls in part a flow of fluid from the inlet to the outlet, and wherein a change in axial position of 200 μm causes at least one of:

i) a change in flow rate of at least one of:

(1) at least 1 LPM;

(2) at least 2 LPM;

(3) less than 4 LPM; or

(4) between 2 LPM and 3 LPM; or

ii) a change in flow pressure of at least one of:

(1) at least 5 mmHg;

(2) at least 10 mmHg;

(3) at least 15 mmHg;

(4) at least 20 mmHg;

(5) at least 25 mmHg;

(6) at least 30 mmHg;

(7) at least 35 mmHg; or

(8) at least 40 mmHg.

5 . A heart pump according to claim 1 , wherein the outlet at least one of:

a) has a throat area of at least one of:

i) at least 60 mm 2 ;

ii) at least 80 mm 2 ;

iii) at least 120 mm 2 ;

iv) between 60 mm 2 and 250 mm 2 ;

v) between 120 mm 2 and 160 mm 2 ;

vi) between 140 mm 2 and 160 mm 2 ;

vii) between 140 mm 2 and 250 mm 2 ;

viii) between 130 mm 2 and 150 mm 2 ;

ix) approximately 140 mm 2 ; or

x) approximately 150 mm 2 ;

b) has a substantially rectangular cross-sectional shape and a width to height aspect ratio of at least one of:

i) between 1:2 and 2:1;

ii) between 1:1 and 2:1;

iii) between 1:1 and 1.8:1;

iv) between 1.1:1 and 1.6:1; or

v) approximately 1.4:1; or

c) defines a cutwater angle of at least one of:

i) between 0° and 70°;

ii) between 30° and 50°;

iii) between 40° and 45°;

iv) between 35° and 45°;

v) between 0° and 60°; or

vi) approximately 40°.

6 . A heart pump according to claim 1 , wherein the impeller has at least one of:

a) a vane height of at least one of:

i) at least 1.5 mm;

ii) less than 5 mm;

iii) between 1.5 mm and 3 mm;

iv) between 1.7 mm and 2.3 mm;

v) between 1.8 mm and 2.2 mm;

vi) between 1.9 mm and 2.1 mm; or

vii) approximately 2 mm;

b) a vane inlet angle of at least one of:

i) less than 90°;

ii) greater than 60°;

iii) between 70° and 90°;

iv) between 82° and 86°; or

v) approximately 84°; or

c) a vane outlet angle of at least one of:

i) less than 60°;

ii) greater than 20°;

iii) between 30° and 50°;

iv) between 45° and 50°;

v) between 35° and 45°;

vi) between 38° and 42°; or

vii) approximately 45°.

7 . A heart pump according to claim 1 , wherein the impeller includes at least one of:

a) a number of primary vanes, the primary vanes having at least one of:

i) an inner diameter of at least one of:

(1) larger than a diameter of an inflow port;

(2) at least 10 mm;

(3) less than 40 mm;

(4) between 20 mm and 40 mm;

(5) between 25 mm and 35 mm; or

(6) approximately 25-30 mm; or

ii) an outer thickness of at least one of:

(1) at least 5 mm;

(2) less than 20 mm;

(3) between 6 mm and 15 mm;

(4) between 7 mm and 8 mm; or

(5) approximately 7.5 mm;

b) a number of secondary vanes, the secondary vanes having an inner diameter of at least one of:

i) at least 20 mm;

ii) less than 40 mm;

iii) between 30 mm and 40 mm; or

iv) approximately 35 mm;

c) an outer vane diameter of at least one of:

i) at least 20 mm;

ii) less than 60 mm;

iii) between 45 mm and 55 mm;

iv) between 48 mm and 52 mm; or

v) approximately 50 mm;

d) an equal number of primary and secondary vanes;

e) at least three primary and secondary vanes;

f) less than six primary and secondary vanes; or

g) four primary and four secondary vanes.

8 . A heart pump according to claim 1 , wherein in a region of the outlet volute the cavity has at least one of:

a) a base circle diameter of at least one of:

i) at least 40 mm;

ii) at least 50 mm;

iii) less than 100 mm;

iv) less than 80 mm;

v) between 50 mm and 74 mm;

vi) between 54 mm and 64 mm; or

vii) approximately 60 mm; or

b) an outer wall diameter of at least one of:

i) at least 50 mm;

ii) less than 100 mm;

iii) less than 80 mm;

iv) between 50 mm and 80 mm;

v) between 65 mm and 76 mm; or

vi) approximately 71 mm.

9 . A heart pump according to claim 8 , wherein over the defined flow range the maximum radial force generated by the volute is less than 1.0 N, and wherein the defined flow range is at least one of:

a) at least 5 LPM to 8 LPM;

b) 3 LPM to 12 LPM, or

c) 3 LPM to 15 LPM.

10 . A heart pump according to claim 1 , wherein the heart pump is configured to provide at least partial right ventricular function.

11 . A heart pump according to claim 1 , wherein at least one of:

a) the heart pump has a pump performance curve having a gradient less than at least one of:

i) −30%;

ii) −35%;

iii) −40%;

iv) −75%;

v) −100%; or,

vi) −150%; or

b) an axial position of the impeller within the cavity controls in part a flow of fluid from the inlet to the outlet, and wherein a change in axial position of 200 μm causes at least one of:

i) a change in flow rate of at least one of:

(1) at least 0.2 LPM;

(2) at least 0.5 LPM;

(3) less than 2 LPM; or

(4) between 0.5 LPM and 1.5 LPM; or

ii) a change in flow pressure of at least one of:

(1) at least 1 mmHg;

(2) at least 2 mmHg;

(3) at least 5 mmHg; or

(4) at least 10 mmHg.

12 . A heart pump according to claim 1 , wherein the outlet at least one of:

a) has a throat area of at least one of:

i) at least 100 mm 2 ;

ii) at least 130 mm 2 ;

iii) between 130 mm 2 and 250 mm 2 ;

iv) between 130 mm 2 and 230 mm 2 ;

v) between 170 mm 2 and 210 mm 2 ;

vi) between 140 mm 2 and 200 mm 2 ;

vii) between 140 mm 2 and 210 mm 2 ;

viii) between 150 mm 2 and 200 mm 2 ;

ix) approximately 233 mm 2 ;

x) approximately 175 mm 2 ; or

xi) approximately 150 mm 2 ;

b) has a substantially rectangular cross-sectional shape outlet and a width to height aspect ratio of at least one of:

i) between 1:3 and 1:1;

ii) approximately 0.45-0.65:1; or

iii) a width of between 8 mm and 12 mm;

c) defines a cutwater angle that is at least one of:

i) between 90° and 180°;

ii) between 90° and 135°;

iii) between 0° and 90°;

iv) between 45° and 90°;

v) between 45° and 135°;

vi) between 60° and 80°; or

vii) approximately 70°.

13 . A heart pump according to claim 1 , wherein the impeller has at least one of:

a) a vane height of at least one of:

i) at least 10 mm;

ii) less than 30 mm;

iii) between 10 mm and 25 mm;

iv) between 15 mm and 20 mm;

v) between 17 mm and 18 mm; or

vi) approximately 17.5 mm;

b) a vane inlet angle of at least one of:

i) greater than 60°;

ii) less than 115°;

iii) between 80° and 100°; or

iv) approximately 90°; or

c) a vane outlet angle of at least one of:

i) greater than 60°;

ii) less than 115°;

iii) between 80° and 100°;

iv) approximately 72° L, or

v) approximately 90°.

14 . A heart pump according to claim 1 , wherein the impeller includes:

a) a number of primary vanes, the primary vanes having at least one of:

i) an inner diameter of at least one of:

(1) at least 10 mm;

(2) less than 25 mm;

(3) between 10 mm and 20 mm;

(4) between 14 mm and 18 mm; or

(5) 16 mm;

ii) a thickness of at least one of:

(1) at least 0.5 mm;

(2) less than 3.0 mm;

(3) between 0.75 mm and 2.5 mm; or

(4) 1.5 mm; or

iii) a filleted edge of between 0.25 mm and 1.14 mm,

b) a number of secondary vanes, the secondary vanes having an inner diameter of at least one of:

i) at least 10 mm;

ii) less than 25 mm;

iii) between 15 mm and 25 mm;

iv) between 18 mm and 20 mm; or

v) approximately 19 mm;

c) an outer vane diameter of at least one of:

i) at least 15 mm;

ii) less than 40 mm;

iii) between 20 mm and 30 mm;

iv) between 22 mm and 27 mm;

v) approximately 24 mm; or

vi) approximately 25 mm;

d) an equal number of primary and secondary vanes;

e) between three and five primary vanes;

f) four primary vanes;

g) between three and six secondary vanes;

h) four secondary vanes; or

i) four primary vanes and four secondary vanes.

15 . A heart pump according to claim 1 , wherein at least one of:

a) the inlet has a diameter of at least one of:

i) at least 10 mm;

ii) at least 15 mm;

iii) less than 30 mm;

iv) less than 25 mm;

v) between 18 mm and 22 mm; or

vi) approximately 19 mm to 20 mm; or

b) the cavity has a diameter of a least one of:

i) at least 20 mm;

ii) at least 25 mm;

iii) less than 40 mm;

iv) less than 30 mm;

v) between 27 mm and 29 mm; or

vi) approximately 28 mm.

16 . A heart pump according to claim 1 , wherein the impeller includes a rotor having at least one of:

a) a height of at least one of:

i) at least 5 mm;

ii) less than 15 mm;

iii) between 6 mm and 13 mm;

iv) between 8 mm and 11 mm; or

v) approximately 10 mm; or

b) an outer circumferential wall spaced from an inner cavity wall by at least one of:

i) an average distance of at least 2 mm;

ii) an average distance of less than 8 mm;

iii) an average distance of less than 5 mm; or

iv) an average distance of approximately 4 mm.

17 . A heart pump according to claim 1 , wherein:

a) the impeller includes first and second sets of vanes provided on a rotor body, the rotor being positioned within the cavity to define:

i) a first cavity portion having a first inlet and a first outlet, the first set of vanes being provided within the first cavity portion so as to define a first pump that provides at least partial left ventricular function; and,

ii) a second cavity portion having a second inlet and a second outlet, the second set of vanes being provided within the second cavity portion so as to define a second pump that provides at least partial right ventricular function and wherein at least one of:

(1) the axial position of the impeller determines a separation between each set of vanes and a respective housing surface, the separation being used to control the fluid flows from the inlets to the outlets; or

(2) the first and second pumps have respective pump performance curves having different gradients so that a change in rotational speed of the pump causes a change in the relative flows of the first and second pumps;

b) the drive is positioned at a first end of the cavity and includes:

i) a number of circumferentially spaced permanent magnets mounted in the rotor of the impeller, adjacent magnets having opposing polarities; or

ii) at least one drive coil that in use generates a magnetic field that cooperates with the magnetic material allowing the impeller to be rotated; or

c) the pump includes a magnetic bearing for controlling an axial position of the impeller within the cavity and wherein the magnetic bearing is positioned at a second end of the cavity and includes:

i) first and second annular magnetic bearing members mounted within and proximate a face of the rotor, the first magnetic bearing member being outwardly of the second magnetic bearing member;

ii) a number of circumferentially spaced substantially U-shaped bearing stators mounted in the housing proximate the second end of the cavity, each U-shaped bearing stator having first and second bearing stator legs substantially radially aligned with the first and second magnetic bearing members respectively; or

iii) at least one bearing coil on each bearing stator that generates a magnetic field that cooperates with the magnetic bearing members to thereby at least one of:

(1) control an axial position of the impeller; or

(2) at least partially restrain radial movement of the impeller.

18 . A heart pump according to claim 17 , wherein the first and second pumps have at least one of:

a) a design pressure ratio at 6 LPM in a range of 3.5 to 4.5:1;

b) an axial pressure sensitivity of at least one of:

i) at least 20 mmHg/mm; or

ii) approximately 60 mmHg/mm; or

c) a change in design pressure ratio at 6 LPM in a range of 3.25 to 4.75:1.

19 . A heart pump according to claim 17 , wherein the housing and impeller cooperate to provide a shunt flow path between the first and second cavity portions, the shunt flow path having a cross-sectional area that is at least one of:

a) at least 15 mm 2 ;

b) no greater than 50 mm 2 ;

c) between 20-50 mm 2 ;

d) approximately 25 mm 2 ; or

e) adjustable by controlling an axial position of the impeller within the cavity.

20 . A heart pump according to claim 1 , wherein volute includes a split volute.