Arrangement with a blood pump and a gas exchanger for extracorporeal membrane oxygenation

Abstract

The invention relates to an arrangement having a blood pump and a gas exchanger for extracorporeal membrane oxygenation. According to the invention, the blood pump is designed as a pulsatile blood pump and is arranged with the gas exchanger in the same housing. The pulsatile blood pump and the gas exchanger are preferably connected to the same gas source so that the blood pump can be pneumatically driven. The novel ECMO system has a simple design, is flexible, and in particular can be used directly on the patient.

Claims

1. An arrangement comprising: a housing having a blood inlet, a blood outlet, a first gas inlet, and a second gas inlet; a blood pump within the housing and comprising an expandable member connected to receive gas from the first gas inlet; a gas exchanger for extracorporeal gas exchange within the housing and connected to the second gas inlet; a gas source external to the housing and having at least one gas outlet connected to the first and second gas inlets of the housing; wherein the blood pump is arranged to deliver blood from the blood inlet to the gas exchanger, wherein the first gas inlet is connected to receive gas from the at least one gas outlet of the external gas source to provide pumping power to the expandable member of said blood pump, and wherein, after the gas is delivered to the expandable member of said blood pump, a portion of the gas from the gas source is then delivered from said blood pump to said gas exchanger via the second gas inlet to provide a gas exchange function, and wherein the gas exchanger is separate from the blood pump.

2. The arrangement according to claim 1, further comprising a blood inlet line connected to the blood inlet on the housing and a blood outlet line connected to the blood outlet on the housing, wherein each of the blood inlet line and the blood outlet line include cannulas or tube connections configured to access a patient's blood vessels.

3. The arrangement according to claim 2, wherein the blood inlet line and a blood outlet line each have a length of 80 cm or less.

4. The arrangement according to claim 2, wherein the blood inlet and the blood outlet are arranged on the housing so that the blood inlet line and the blood outlet line are oriented in the same direction.

5. The arrangement according to claim 2, wherein the blood inlet and the blood outlet are disposed on the same end of the housing.

6. The arrangement according to claim 2, wherein the blood inlet and the blood outlet are disposed on opposite ends of the housing.

7. The arrangement according to claim 1, further comprising: a pressure valve disposed to receive gas from the at least one gas outlet of the gas source, such that when a pressure of the gas outlet exceeds a preset value, gas is provided to said gas exchanger.

8. The arrangement according to claim 1, wherein the blood pump is axially aligned with the gas exchanger.

9. The arrangement according to claim 8, wherein the blood pump is coaxially aligned inside the gas exchanger.

10. The arrangement according to claim 1, wherein the blood pump is disposed on an end face of the gas exchanger and the expandable member comprises a flexible diaphragm.

11. The arrangement according to claim 1, wherein the at least one gas outlet of the gas source provides gas under pressure to both said blood pump and said gas exchanger.

12. The arrangement according to claim 1, wherein the expandable member of the pulsatile blood pump comprises a balloon.

13. The arrangement according to claim 1, wherein the expandable member of the pulsatile blood pump comprises a diaphragm which is pre-tensioned such that its passive position is that having the maximum filling of the pump.

14. The arrangement according to claim 1, wherein the gas exchanger is connected via a valve to the at least one gas outlet of the gas source.

15. The arrangement as in claim 1, wherein after the gas has been delivered from the gas source to the expandable member, the gas is fed to the gas exchanger in a separate line.

16. The arrangement as in claim 1, wherein the gas source comprises a pneumatically operated gas console connected to one or more of a gas cylinder or a centralized supply line.

17. The arrangement as in claim 16, wherein the first and second gas inlets are connected to the pneumatically operated gas console.

18. The arrangement as in claim 1, wherein the gas exchange function provided comprises one or more of oxygenating the blood or reducing CO2 in the blood.

19. The arrangement as in claim 1 wherein the housing is rigid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Different arrangements according to the invention are shown in the figures, which serve as exemplary embodiments. Shown are:

(2) FIG. 1 an ECMO system consisting of a drive console and patient system with bypass for supplying the oxygenator,

(3) FIG. 2 an arrangement in accordance with FIG. 1 with two lines between drive console and patient system,

(4) FIG. 3 an arrangement with a pressure relief valve between drive console and patient system,

(5) FIG. 4 a housing with a radially internal balloon and two radially internal valves,

(6) FIG. 5 a housing in accordance with FIG. 4 with only one radially internal valve,

(7) FIG. 6 a housing with barrel-shaped gas exchanger fibers and a blood pump arranged on an end face,

(8) FIG. 7 a housing with annularly arranged gas exchanger fibers and a blood pump arranged on an end face,

(9) FIG. 8 a housing in which the blood pump and gas exchanger are arranged side by side in parallel, and

(10) FIG. 9 a system with a mechanically powered pump.

DETAILED DESCRIPTION OF THE INVENTION

(11) The basis of the invention is an ECMO system, which pumps the blood with a positive displacement pump and in which the drive power is released by the compressed respiration gas. In this arrangement the gas is fed to a pneumatically operating drive console 1. The console generates an alternating rising and falling pressure, which is fed via a line 2 to the pump of the patient system 3 (FIG. 1).

(12) After the gas has passed through the console, instead of being passed to the environment it can be fed to the oxygenator of the patient system via a separate line 4 (FIG. 2). A more effective utilization of the gas is therefore obtained.

(13) Furthermore, a solution is proposed in which, as described, a rising and falling pressure is fed to the pump and on the patient system 3 a pressure relief valve 6 is connected in parallel with the pump 5, which is connected on the other side to the gas exchanger or oxygenator 7 of the patient system, and which at the same time supplies this with respiration gas at the upper pressure level (FIG. 3), There is therefore only one supply line 8 to the patient system.

(14) As described above, a pulsatile blood pump is combined with an oxygenator in a compact unit, the patient system. The following schemes are proposed for this purpose.

(15) In one scheme (FIG. 4) a balloon 10 is located in the pump chamber 9, which is centrally arranged, and this balloon 10 is pressurized and relaxed with compressed air in a pulsatile manner with a connecting hose 11. The blood passes from the patient via a nozzle 12 and a valve 13 to reach the pumping chamber 9. Through a second valve 14 the blood reaches the gas exchanger fibers 15, which can be arranged in an annular pattern. These are radially permeated and the blood thus reaches the outlet 16. Opposite the outlet 16 a ventilation port 16 is provided, to simplify the filling and bleeding of the system.

(16) In an alternative arrangement (FIG. 5), the second valve 18 is located behind the gas exchanger fibers in the flow direction.

(17) In a further scheme (FIG. 6) the blood passes through a valve 19 into a pump chamber 20 which is bounded on one side by a flexible diaphragm 21, and through a second valve 22a or 22b to the gas exchanger fibers 23. The membrane is connected on the other side to a connecting hose 24 and via this it is pressurized and relaxed with compressed air by the drive assembly in a pulsatile manner. The gas exchanger fibers 23 can be in a barrel-shaped (FIG. 6) or annular (FIG. 7) arrangement. While in the barrel-shaped arrangement the valve 22a is seated externally, in the annular arrangement is arranged centrally 22b. After the blood flows through the oxygenation region, diagonally in the barrel-shaped fiber arrangement or radially in the annular arrangement, it reaches the outlet 23, positioned low down, and from there passes back to the patient. When filling the system a ventilation port 17 near the outlet is useful. This is applied at the highest point of the system.

(18) In a further scheme (FIG. 8) the pump unit and the gas exchanger unit are arranged in parallel. The blood passes through a nozzle 26 and 27 via a valve into the pump chamber 28, in which a balloon 29 is located. This is pressurized with compressed air and relaxed in a pulsatile manner via the supply line 30. Through an additional valve 31 the blood reaches the gas exchanger fibers 32 and from there passes back to the patient via the outlet nozzle 33.

(19) In all solutions the gas exchanger fibers are supplied with respiration gas and the respiration gas is discharged via an inlet and outlet line 34.

(20) Is conceivable that, in the solutions with the diaphragm (FIGS. 6 and 7), these are mechanically driven by a pressure plate 35 and a plunger 36 (FIG. 9). For this purpose a drive console with a suitable actuator is used. This actuator can also be pneumatic.

(21) Various valve geometries are proposed for the solutions described. This means that the invention can be implemented with ball valves as shown. Conical valves, disk valves or diaphragm valves are also conceivable, however.

(22) By various geometric arrangements of the pump chambers, valves, design of the valves and oxygenator fibers in combination with both schemes, different designs emerge which facilitate an extremely compact ECMO system.

(23) It is proposed to configure the blood inlet and outlet lines in one geometric direction, in order to simplify the connection to the patient and to keep the connection cannulas as short as possible.

(24) It is proposed to produce, deliver and store the system optionally already filled, so that it is quickly ready for use.

(25) The pulsatile blood pumping has an advantageous effect on the gas exchange in the oxygenator and the elution of the whole system by a continuous mixing of the blood, and an improved elution of critical areas. Thus, the formation of thrombi is counteracted.

(26) Both functional principles, in addition to the gas exchanger can also be combined with a heat exchanger.

(27) Since the pump energy is transferred via only one gas connection (with the exception of the last solution) and not mechanically via an electric motor connected to the system as is current practice, the system can be positioned more flexibly and closer to, or on, the patient.

(28) This results in different options for driving the pulsatile pump, which makes the device combination and usage more flexible.

(29) Since oxygen for the gas exchange in the oxygenator is available in compressed form in gas cylinders or via a centralized supply line, this gas pressure can be used to also facilitate the pulsatile drive using a suitable pneumatic circuit. No additional energy source is thus required, which facilitates a more compact, simpler and less expensive drive.