Systems, Devices and Methods for Cardiopulmonary Treatment and Procedures

• US 20090099498A1
• Filed: 10/10/2008
• Published: 04/16/2009
• Est. Priority Date: 10/12/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Demers, Jason A., Gray, Larry B., Dale, James D., Altobelli, David E., Perry, N. Christopher
• Granted Patent: US 8,105,265 B2
• Time in Patent Office: Days
• US Class Current: 604/6.09
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36223 the cassette being adapted for heating or cooling the blood
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3666 Cardiac or cardiopulmonary bypass, e.g. heart-lung machines
• CPC Class Codes: A61M 1/3667 with assisted venous return
• CPC Class Codes: A61M 2205/127 with provisions for heating or cooling
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/427 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/531 using blood pressure data, e.g. from blood pressure sensors
• CPC Class Codes: A61M 60/554 of blood pressure
• CPC Class Codes: G01F 22/02 involving measurement of pressure
• CPC Class Codes: Y10T 137/86035 Combined with fluid receiver

Abstract

A cardiopulmonary bypass system utilizing membrane-based reciprocating positive displacement blood pumps (“pod pumps”). In one aspect, the pod pumps are constructed to provide reduced shear forces on the blood being pumped. In another aspect blood flow through the pod pumps can be controlled by a controller using information from pressure sensors in the control chamber of the pod pumps. In another aspect, the pod pumps are included on a disposable unit that can be received and held by a receptacle means on a base unit, the base unit also providing pressurized control fluid to the pod pumps on the disposable unit through the receptacle means.

Claims

1. A cardiopulmonary bypass system including tubing for fluidly connecting to a venous access site of a subject, an oxygenator, a reciprocating positive displacement pump for pumping blood through the oxygenator, and tubing for fluidly connecting to an arterial access site of the subject, wherein the reciprocating positive displacement pump comprises:

a curved rigid chamber wall;

a flexible membrane attached to the rigid chamber wall, the flexible membrane and rigid chamber wall defining a pumping chamber;

an inlet for directing flow through the rigid chamber wall into the pumping chamber in a direction substantially tangential to the rigid chamber wall, and;

an outlet for directing flow through the rigid chamber wall out of the pumping chamber in a direction substantially tangential to the rigid chamber wall.

2. A cardiopulmonary bypass system including tubing for fluidly connecting to a venous access site of a subject, an oxygenator, a reciprocating positive displacement pump for pumping blood through the oxygenator, and tubing for fluidly connecting to an arterial access site of the subject, wherein the reciprocating positive displacement pump comprises:

a curved rigid chamber wall;

a flexible membrane attached to the rigid chamber wall, the flexible membrane and rigid chamber wall defining a pumping chamber;

an inlet and an outlet in the rigid chamber wall of the pumping chamber;

a rigid limit structure for limiting movement of the membrane and limiting the maximum volume of the pumping chamber, the flexible membrane and the rigid limit structure defining a control chamber;

an opening in the rigid limit structure through which pressurized fluid can cause movement of the membrane;

a valve fluidly connected to the opening for directing pressurized fluid to the control chamber;

a pressure sensor in fluid communication with the control chamber; and

a controller to receive information from the pressure sensor, and to control movement of the valve;

wherein

the controller can calculate the volume of liquid in the pumping chamber and control the valve to regulate the pressure in the control chamber.

3. A cardiopulmonary bypass system comprising:

tubing for fluid communication with a venous access site of a subject, an oxygenator;

a disposable unit including an inlet line, at least one valve, at least two reciprocating positive displacement pumps for pumping blood through the oxygenator, and an outlet line;

the reciprocating positive displacement pumps each having a pumping chamber separated from a control chamber by a flexible membrane;

each control chamber having a port for fluidly connecting to a base unit,

the base unit including receptacle means for receiving and holding the disposable unit, and for placing a pressurized control fluid source in fluid communication with each port of each control chamber; and

tubing for fluid communication with an arterial access site of the subject, wherein the base unit is capable of receiving and holding disposable units having reciprocating positive displacement pumps the pumping chambers of which can have different volumes.

4. A cardiopulmonary bypass system comprising:

a blood flow inlet channel fluidly connected to the outlet of an oxygenator;

the blood flow inlet channel fluidly connected to the inlet of a reciprocating positive displacement first pump having a pumping chamber separated from a control chamber by a flexible membrane, the control chamber fluidly connected to a first pressure transducer;

a blood flow outlet channel fluidly connected to the outlet of the reciprocating positive displacement first pump;

a medical solution inlet channel fluidly connected to the outlet of a container containing a medical solution;

the medical solution inlet channel fluidly connected to the inlet of a reciprocating positive displacement second pump having a pumping chamber separated from a control chamber by a flexible membrane, the control chamber fluidly connected to a second pressure transducer;

a medical solution outlet channel fluidly connected at a first end to the outlet of the reciprocating positive displacement second pump, and fluidly connected at a second end to the blood flow outlet channel; and

a controller for receiving information from the first and second pressure transducers and for controlling the fluid output of the first pump and the second pump;

wherein the controller can calculate the flow rate through the first pump from the information from the first pressure transducer, and the flow rate through the second pump from the information from the second pressure transducer, and can adjust the flow rate of the second pump according to the flow rate of the first pump, thereby maintaining a desired ratio of a medical solution flow rate to a blood flow rate.

5. A combination blood filter having an upper inlet and first and second lower outlets comprising:

a housing defining a first cylindroid volume for directing blood in a circular downward path;

a first filter for removing matter larger than a first size from blood, the first filter defining a second volume and being located within the first volume;

the second volume fluidly connected to the first outlet;

a second filter for removing matter larger than a second size from blood, the second size being smaller than the first size;

the second filter defining a third volume and being located within the second volume;

the third volume fluidly connected to the second outlet; and

a selector valve for selectably directing blood flow through the combination blood filter, wherein

blood can flow through the first outlet with the selector valve in a first mode, and blood flow can flow through the second outlet with the selector valve in a second mode.

6. An extracorporeal blood flow system comprising:

an air removal container having an upper blood inlet, a lower blood outlet and an air vent near the top of the air removal container, the air vent sealingly connected to a negative pressure source;

a blood pump having a pump inlet and a pump outlet;

a fluid path from the outlet of the air removal container to the inlet of the blood pump;

a reservoir containing a liquid with a blood inlet and a blood outlet;

a secondary reservoir inlet fluid path branching from the pump outlet and fluidly connected to the inlet of the reservoir;

a secondary reservoir outlet fluid path branching from the pump inlet and fluidly connected to the outlet of the reservoir;

a first valve means to control flow of blood from the reservoir to the pump inlet and a second valve means to control flow of blood from the pump outlet to the reservoir;

a pressure sensor in fluid communication with the air vent, and capable of measuring air pressure within the air removal container; and

a controller for receiving the pressure information from the pressure sensor, and for controlling the valve means, wherein

the controller can monitor the air pressure within the air removal container, and control the first and second valve means to cause the liquid from the reservoir to flow into the blood pump upon detection of a change in the air pressure within the air removal container.

7. A method of conducting cardiac bypass comprising:

providing a reciprocating positive-displacement pump having

a curved rigid chamber wall;

a flexible membrane attached to the rigid chamber wall, so that the flexible membrane and rigid chamber wall define a pumping chamber;

an inlet for directing flow through the rigid chamber wall into the pumping chamber in a direction that is substantially tangential to the rigid chamber wall; and

an outlet for directing flow through the rigid chamber wall out of the pumping chamber in a direction that is substantially tangential to the rigid chamber wall;

providing an oxygenator;

providing blood from a patient; and

pumping the blood using the reciprocating positive-displacement pump so as to cause the blood to flow through the oxygenator and back to the patient after being oxygenated.

8. A method according to claim 7, wherein the reciprocating positive-displacement pump is provided with a rigid limit structure for limiting movement of the membrane and limiting the maximum volume of the pumping chamber, the flexible membrane and the rigid limit structure defining a control chamber.

9. A method according to one of claims 7 or 8, wherein the reciprocating positive-displacement pump is provided with a rigid chamber wall that is hemispheroid.

10. A method according to claim 8, wherein the reciprocating positive-displacement pump is provided with a rigid chamber wall is hemispheroid, and a rigid limit structure that limits movement of the flexible membrane such that the rigid chamber and the flexible membrane urged against the rigid limit structure define the pumping chamber as a spheroid when the pumping chamber is at maximum volume.

11. A method according to claim 10, wherein the reciprocating positive-displacement pump is provided with a rigid limit structure that is a hemispheroid limit wall that, together with the flexible membrane, defines a spheroid control chamber when the pumping chamber is at minimum volume.

12. A method according to one of claims 8-11, wherein the reciprocating positive-displacement pump is provided with a pneumatic actuation system that intermittently provides either a positive or a negative pressure to the control chamber.