Blood pump

• US 10,363,350 B2
• Filed: 06/28/2018
• Issued: 07/30/2019
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Magenta Medical Ltd.
• Original Assignee: Magenta Medical Ltd.
• Inventors: Schwammenthal, Ehud, Tuval, Yosi, Glozman, Daniel
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US16/022,445
• Publication Number:
  US 20180303993A1
• Time in Patent Office: 397 Days
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 2210/1082 Kidney
• CPC Class Codes: A61M 2210/12 Blood circulatory system
• CPC Class Codes: A61M 60/13 by means of a catheter allowing explantation, e.g. catheter pumps temporarily introduced via the vascular system
• CPC Class Codes: A61M 60/135 inside a blood vessel, e.g. using grafting
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/237 the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps
• CPC Class Codes: A61M 60/33 of kidneys
• CPC Class Codes: A61M 60/411 generated by an electromotor
• CPC Class Codes: A61M 60/414 transmitted by a rotating cable, e.g. for blood pumps mounted on a catheter
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/808 specially adapted for deformable impellers, e.g. expandable impellers
• CPC Class Codes: A61M 60/81 Pump housings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: A61M 60/833 Occluders for preventing backflow
• CPC Class Codes: A61M 60/861 Connections or anchorings for connecting or anchoring pumps or pumping devices to parts of the patient's body
• CPC Class Codes: A61M 60/896 having flexible or resilient parts, e.g. flap valves

Abstract

Apparatus and methods are described including identifying a subject as suffering from cardiac dysfunction, congestive heart failure, reduced renal blood flow, increased renal vascular resistance, arterial hypertension, and/or kidney dysfunction, and, in response thereto, reducing blood pressure within a renal vein of the subject, by activating at least one impeller to pump blood from the renal vein into a vena cava of the subject, by the impeller rotating.

Claims

1. A method comprising:

measuring central venous pressure of a subject;

at least partially based upon the measured central venous pressure, designating a target renal venous pressure that is lower than the measured central venous pressure; and

in response thereto, driving at least one impeller to pump blood from a renal vein of the subject into a vena cava of the subject, such as to reduce the subject'"'"'s renal venous pressure toward the target renal venous pressure.

2. The method according to claim 1, wherein driving the impeller to pump blood from the renal vein into the vena cava comprises enhancing a rate of blood flow from the renal vein into the vena cava, without causing a substantial change in a direction of the blood flow relative to a direction of blood flow from the renal vein into the vena cava in an absence of driving the impeller to pump blood from the renal vein into the vena cava.

3. The method according to claim 1, wherein driving the impeller to pump blood from the renal vein into the vena cava comprises driving the impeller to pump blood from the renal vein directly into a portion of the vena cava that is adjacent to the renal vein.

4. The method according to claim 1, wherein driving the impeller to pump blood from the renal vein into the vena cava comprises driving the impeller to pump blood from the renal vein into the vena cava, without removing blood from a venous system of the subject into a non-venous receptacle.

5. The method according to claim 1, further comprising:

using one or more sensors, measuring pressure within the subject'"'"'s veins at a first location that is upstream of the impeller, and at a second location that is downstream of the impeller; and

controlling rotation of the impeller responsively to the pressure measured at the first and second locations.

6. The method according to claim 1, further comprising:

using one or more sensors, measuring flow through the subject'"'"'s renal vein; and

controlling rotation of the impeller responsively to the measured flow.

7. The method according to 6, wherein measuring flow through the subject'"'"'s renal vein comprises measuring flow using a thermal flow sensor that is disposed within a housing, the housing being configured such that blood flow through the housing is substantially in a direction parallel to a local longitudinal axis of the renal vein.

8. The method according to claim 1, wherein driving the at least one impeller to pump blood from the renal vein into the vena cava comprises driving the at least one impeller to pump blood from the renal vein into the vena cava while the impeller is disposed within a cage that is configured to separate an inner wall of a vein of the subject in which the impeller is placed from the impeller.

9. The method according to claim 8, wherein driving the at least one impeller to pump blood from the renal vein into the vena cava while the impeller is disposed within the cage comprises driving the at least one impeller to pump blood from the renal vein into the vena cava while the impeller is disposed within the cage, the cage and the impeller being engaged with respect to one another by an engagement mechanism, such that in response to the cage becoming radially compressed, the impeller becomes axially elongated such that the cage maintains a separation between the wall of the vein and the impeller.

10. The method according to claim 8, wherein driving the at least one impeller to pump blood from the renal vein into the vena cava while the impeller is disposed within the cage comprises driving the at least one impeller to pump blood from the renal vein into the vena cava while the impeller is disposed within the cage, and while the cage is maintained in a rotationally fixed position.

11. The method according to claim 8, wherein the cage includes struts that are shaped to define cells, the method further comprising radially expanding the cage such as to separate the inner wall of the vein from the impeller even if the inner wall protrudes through a cell of the cage.

12. The method according to claim 8,

wherein the vein in which the impeller is placed has a given diameter in an absence of the cage;

the method further comprising;

widening a portion of the vein in which the impeller is placed such that a diameter of the portion of the vein in which the impeller is placed is greater than the given diameter, by radially expanding the cage comprises; and

radially expanding the impeller such that a span of the impeller is at least equal to the given diameter.

13. The method according to claim 8, further comprising placing the impeller and the cage inside a body of the subject, while the cage and impeller are in radially-constrained configurations thereof, and deploying the cage and the impeller and the cage inside the subject'"'"'s body by causing the impeller and the cage to assume non-radially-constrained configurations in which the impeller and the cage are radially expanded relative to their respective radially constrained configurations.