# Patent

## Title
Apparatus for making extracorporeal blood circulation available

## Abstract

An apparatus for providing an extracorporeal blood circuit control includes a base module having a control device and a patient module releasably connected to the base module and having blood-conducting components of the extracorporeal blood circuit. A pivot system is also provided at the base module and at the patient module to pivot the patient module relative to the base module about a horizontal axis.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of European Patent Application No. EP 04 027 855.8 filed on Nov. 24, 2004, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to an apparatus for the provision of an extracorporeal blood circuit, in particular heart-lung machines, comprising at least one base module having a control device and a patient module releasably connected to the base module and having blood-conducting components of the extracorporeal blood circuit.
BACKGROUND OF THE INVENTION
Heart-lung machines of this type are known, for example, as portable devices for emergency use. It is a problem in this respect that it must be ensured with devices of this type prior to the putting into operation that there is no longer any air in the blood-conducting components of the extracorporeal blood circuit, since this could seriously endanger a patient. A so-called priming liquid is therefore filled in and the extracorporeal blood circuit is vented or deaerated prior to the putting into operation in order to eliminate the air bubbles present in the blood-conducting components. This is, however, time-consuming with the known apparatus.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus of the initially named kind with which the venting of a patient module filled with priming liquid can take place in a short time.
This object is satisfied in particular in that pivot means are provided at the base module and/or at the patient module to pivot the patient module relative to the base module about a horizontal axis from a filling position into an operating position.
The patient module can be pivoted in a guided manner relative to the base module by the pivot means provided in accordance with the invention, whereby the position and orientation of individual components of the extracorporeal blood circuit is modified so that air bubbles which cannot escape in the filling position due to the design can be removed from the system at or after the transition to the operating position via venting lines.
The filling and venting of a patent module can take place in a time period in the order of magnitude of approximately 2 minutes due to the pivot means in accordance with the invention, whereas comparable apparatus in accordance with the prior art require approximately 20 minutes for this procedure, which can be decisive in emergency situations.
Advantageous embodiments of the invention are described in the description, in the drawing and in the dependent claims.
In accordance with a first advantageous embodiment, there is approximately 90° between the filling position and the operating position, which has the advantage that any air bubbles can reliably escape from the blood-conducting components.
In accordance with a further advantageous embodiment, a blood reservoir is provided in the patient module and is arranged at an inclination of approximately 45° to the horizontal both in the filling position and in the operating position. This has the consequence that the blood reservoir again has the same orientation relative to the horizontal after a rotation of the patient module by 90° so that the same flow conditions result inside the reservoir before and after the pivoting.
In accordance with a further advantageous embodiment, a centrifugal pump head having a central inlet and a tangential outlet can be arranged in the patient module such that the inlet is oriented vertically upwardly in the filling position and horizontally in the operating position. In this manner, the pump head can be filled with priming liquid from above without air bubbles remaining in the pump head in this process. It can likewise be advantageous in this process to provide the centrifugal pump head with a tangential outlet which is arranged at the bottommost position of the centrifugal pump head in the operating position. It is ensured in this manner that no air is pumped inside the intracorporeal blood circuit by the centrifugal pump in operation.
In accordance with a further advantageous embodiment, an arterial filter having a venting outlet can be arranged in the patient module such that the venting outlet is oriented horizontally in the filling position and vertically upwardly in the operating position. The possibility hereby in turn results that air inside the arterial filter, which is still present in the filter after the filling with priming liquid, can escape upwardly via the venting outlet after a pivoting into the operating position.
The pivot means provided in accordance with the invention can be provided in the most varied designs and can in particular include a mount for the patient module pivotally supported at the base module. In this case, the patient module only has to be coupled to the mount in order to permit a guided pivot movement. It is particularly advantageous in this process for the pivot means to include a guide provided at the mount and at the patient module. In this case, the patient module can also be used to ensure the guided pivot movement.
It is alternatively possible to connect the patient module to a further module, for example to a control module, and to fasten the unit of patient module and control module to the mount. In this case, the guide can be provided at the mount and at the control module.
It is also possible, for example, to provide a pivot bearing at the base module into which the other module or other modules are inserted.
The patient module is preferably in the operating position after being placed onto the base module since, in this case, a fast removal of the patient module from the base module is ensured without a pivoting having to be carried out beforehand.
In accordance with a further advantageous embodiment, the base module has a device stand which is provided with a pivotal hook to hang the apparatus on the frame of a patient's bed.
In accordance with a further aspect of the invention, it relates to a method for the putting into operation of an apparatus of the aforementioned type, with the patient module first being brought into the filling position in which filling position the blood-conducting components are filled with a priming liquid, with the patient module subsequently being pivoted relative to the base module, in particular by 90°, into the operating position. The advantages described above result with such a method.
In accordance with an advantageous method variant, a pump head provided in the patient module can be driven prior to the pivoting in order to pump the already filled-in priming liquid and thereby to further vent the blood-conducting components.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.



BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of a portable heart-lung machine;
FIG. 2 is a perspective view of the control module of the heart-lung machine of FIG. 1 connected to a mount of the base module;
FIG. 3 is a perspective view of some blood-conducting components of the patient module in the filling position;
FIG. 4 is the representation of FIG. 3 in the operating position, but in a view from the rear; and
FIG.5 is a diagram showing the individual components of the heart-lung machine.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
The heart-lung machine shown in FIGS. 1 to 4, is composed of three modules, namely a base module B provided with a device stand 10, a control module S and a patient module P which has blood-conducting components of an extracorporeal blood circuit.
In the embodiment shown, the patient module P is coupled via latch elements (not shown) to the control unit S to form a unit and this unit, consisting of the control module S and the patient module P is releasably latched to a mount 12 of the base module B.
As FIG. 1 shows, the device stand 10 made from tubular material has a pivotal hook 14 at its upper side which is bent to form a hook at its upper side to permit a hanging to a frame of a patient's bed. The pivotal hook 14 can be pivoted downwardly by 180° from the position shown in FIG. 1 and can be plugged into two holding clips 16, 17 so that the pivotal hook 14 is not in the way on the mounting of the control module S and of the patient module P.
The device stand 10 is fixedly connected to a carrier element 20 of the base module B which has a plug socket 22 for a mains cable. The mount 12 is furthermore pivotally supported in the carrier element 20, as will be explained in more detail in the following.
An operating part 24 is foldably fastened to the left hand side of the carrier element 20 in FIG. 1 and has a touch screen 26 which represents an input and output means for a control device (computer) provided in the base module. As the Figure furthermore shows, the carrier element 20 and the non-folded operating part 24 form an annular jacket for the unit of mount 12, control module S and patient module P. The operating part 24 must be folded open to the left from the position shown in FIG. 1 to mount or remove the unit of control module S and patient module P.
FIG. 2 shows the mount 12 of the base module B of FIG. 1 to which the control module S is releasably connected by means of latch connections 28, 30. The patient module P is not shown in FIG. 2 for a simplified representation. It must, however, be pointed out that a unit of control module S and patient module P is always plugged onto or removed from the mount 12 in operation.
As FIG. 2 further shows, the control module S supplements the disk-segment shaped geometry of the mount 12 and a handle 32 is located at the upper side of the control module S with which the unit of control module S and patient module P, on the one hand, but also the whole heart-lung machine, on the other hand, can be handled when the three modules are fastened to one another as shown in FIG. 1.
To pivot the patient module P only not shown in FIG. 2 relative to the base module B about a horizontal axis from a filling position into an operating position, the mount 12 of the base module B is equipped with two guide rails 34 which are parallel, provided at the outer periphery and cooperate with adjoining guide rails 36 of the control module S. The guide rails 34 and 36 form a continuous guide structure with the aid of which the unit of mount 12, control module S and patient module P can be pivoted relative to the base module B.
As FIG. 2 shows, the guide rails 34 of the pivot mount 12 are provided with a cut-out 38 with whose aid the pivot mount 12 can be guided over two rollers (not shown) provided at the carrier element 20 so that the pivot mount 12 can be pivoted on the support element 20 of the base module B. The toothed arrangement recognizable in FIG. 2 serves for the engagement of a damping mechanism ensuring a uniform and damped pivot movement.
To assemble the pivot mount 12 with the support element 20, the pivot mount 12 is first brought into a substantially vertical position and the cut-outs 38 are guided via the rollers (not shown) provided at the carrier element 20, whereupon the pivot mount 12 can subsequently be pivoted into the position shown in FIG. 1. After the folding open of the operating part 24, the previously assembled unit of control module S and patient module P can be latched on the pivot mount 12. To pivot the patient module P from the now present operating position into a filling position, the now formed unit of control module S, patient module P and pivot mount 12 can be pivoted by 90° by pivoting down the handle 32 so that the control module S is in the position in which the pivot mount 12 was previously located. In this filling position, the blood-conducting components of the patient module P are in the position and orientation shown in FIG. 3 with respect to the horizontal.
FIG. 3 shows some blood-conducting components of the patient module, with the patient module P having been rotated about 90° counterclockwise, starting from FIG. 1. The view shown in FIG. 3 corresponds to a view from other side of the patient module P in comparison with FIG. 1. The wall 40 of the patient module P standing perpendicular in FIG. 3 is thus disposed parallel next to the pivot mount 12, whereas the horizontally oriented wall 42 adjoins the control module S. Furthermore, a plurality of hose connections are now shown in FIG. 3 for a better clear view.
In FIG. 3, the reference numeral 44 designates a centrifugal pump head having a central suction inlet 46 and a radial outlet 48 shown by broken lines in FIG. 4.
Furthermore, an approximately parallelepiped shaped blood reservoir 50 is installed at a position of 45° in the patient module P and its outlet 52 is connected to the inlet 46 of the centrifugal pump head 44 via a hose line (not shown). Venting lines 54 are located at the upper side of the blood reservoir 50. The inlet into the blood reservoir 50 coming from a venous connection is arranged approximately at the centre of the blood reservoir and cannot be recognized in FIGS. 3 and 4.
Furthermore, it can be recognized in FIGS. 3 and 4 that an arterial filter 56 is provided in the patient module P which has a cylindrical shape, with a tangential inlet 58 and a central axial outlet 60 being provided. A venting connection 62 is provided centrally at the end face of the filter disposed opposite the outlet 60.
Further components shown of the patient module P are an oxygenator 64 and various connection elements which are provided at the wall 42 disposed adjacent to the control module S and which serve for the cooperation with terminals, sensors or plug connections, since all blood-conducting components are provided in the patient module P, whereas control components such as the pump drive, valves and other electrical control elements are arranged in the control module S.
FIG. 4 shows the representation of FIG. 3 in the operating position which corresponds to the representation of FIG. 1 in which the control module S and the wall 42 of the patient module P contacting it are oriented vertically.
As a comparison of FIGS. 3 and 4 shows, there is 90° between the filling position (FIG. 3) and the operating position FIG. 4), with the blood reservoir 50 provided in the patient module P being arranged in both positions at an inclination of 45° to the horizontal, since it is installed at 45° in the patient module. The centrifugal pump head 44 is arranged such that the central inlet 46 is oriented vertically upwardly in the filling position (FIG. 3) and horizontally to the side in the operating position (FIG. 4). The outlet 48 (not recognizable in FIG. 3) of the pump head 44 is arranged at the bottommost position of the centrifugal pump head 44 in the operating position shown in FIG. 4 so that the outlet 48 lies beneath the inlet 46.
The arterial filter 56 is also arranged within the patient module such that the venting outlet 62 is oriented horizontally in the filling position and vertically upwardly in the operating position (FIG. 4). The inlet 58 is oriented vertically downwardly in the filling position and horizontally in the operating position, whereas the outlet 60 is oriented horizontally in the filling position and vertically downwardly in the operating position.
FIG. 5 shows the different components of the heart-lung machine in accordance with the invention in which the patient blood coming from a venous connection V is guided via a line 70 into the blood reservoir 50 and flows from there via the outlet 52 into the inlet 46 of the centrifugal pump 44. It is pumped from there via the outlet 48 into the oxygenator 64 and flows from there via the arterial filter 56 to the arterial connection A and from there back into the body of the patient. An internal bypass which can be switched via a valve 72 is designated by reference numeral 71. Reference numeral 73 designates a valve for the inflow line PR with which priming liquid can be guided into the circuit. Reference numerals 74, 75 and 76 each designate pressure sensors. Venting valves are designated by reference numerals 77, 78 and 79, with the valves 77 and 78 switching the vent paths into the upper region of the blood reservoir 50 not filled with blood and the venting valve 79 controlling the venting from the blood reservoir. Reference numeral 80 designates a bubble sensor which controls a fast-closing valve 82 provided in the arterial outlet A if air bubbles are detected. Reference numeral 84 designates a flow sensor and reference numeral 86 an electrical interface.
As the Figure furthermore shows, the oxygenator 64 is provided with inflow lines and outflow lines for water and oxygen to effect an enriching of the blood with oxygen and a temperature control of the blood.
To put the heart-lung machine described above into operation, starting from the representation of FIG. 1, the pivotal hook 14 is first pivoted downwardly by 180° and the operating part 24 is folded to the left. Subsequently, the total unit consisting of the control module S, the patient module P and the pivot mount 12 can be pivoted counterclockwise so that the filling position is reached.
Priming liquid, which first (cf. FIG. 5) fills the blood reservoir and from there the centrifugal pump head 44, is supplied via the connection PR in the filling position. The air located in the hosing is largely removed from the system in this process by the priming liquid arranged above the machine on filling, with air bubbles, however, remaining in the upper region of the arterial filter 56 and in horizontal line portions.
When the blood reservoir 50 is almost filled, the centrifugal pump head 44 is set into rotation comparatively slowly, whereby the priming liquid is pumped through the system and further air residues are removed from the system. After a time period of approximately 20 seconds, further components—such as the oxygenator 64—are also filled with priming liquid so that the pump can be stopped and the unit of the control module S, patient module P and pivot mount 12 can be pivoted back into the operating position. After these pivoting back by 90°, that air can also escape which had remained in the arterial filter 56 and in horizontal line portions. A complete filling and venting of the patient module can thus be achieved within a time period in the order of magnitude of approximately 2 minutes.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

## Claims

1. A heart-lung machine for providing an extracorporeal blood circuit, comprising:
at least one base module having a control device;
a patient module releasably connected to the base module and having blood-conducting components of the extracorporeal blood circuit disposed thereon; and
pivot means that are provided at one of the base module and the patient module for pivoting the patient module relative to the base module about a horizontal axis from a filling position into an operating position, the blood-conducting components comprising a blood reservoir, a centrifugal pump head, an oxygenator, and a filter, said blood-conducting components being mounted on the patient module to be pivotable together therewith, whereby the positions and orientations of individual components of the extracorporeal blood circuit are such that air bubbles which cannot escape from the extracorporeal blood circuit when the patient module is in the filling position can be removed from the circuit when the patient module is in the operating position through venting lines;
wherein the centrifugal pump head has a central inlet and a tangential outlet and is arranged in the patient module such that the inlet is oriented vertically upwardly in the filling position and horizontally in the operating position and the outlet is arranged at the bottommost position of the centrifugal pump head in the operating position.

2. An apparatus in accordance with claim 1, wherein an angular range of approximately 90° is defined between the filling position and the operating position.

3. An apparatus in accordance with claim 1, wherein the blood reservoir mounted on the patient module is arranged at an inclination of approximately 45° to the horizontal in the filling position and in the operating position.

4. An apparatus in accordance with claim 1, wherein the filter comprises an arterial filter having a venting outlet and that is arranged in the patient module such that the venting outlet is oriented horizontally in the filling position and vertically upwardly in the operating position.

5. An apparatus in accordance with claim 1, wherein the pivot means includes a mount for the patient module pivotally supported at the base module.

6. An apparatus in accordance with claim 5, wherein the pivot means includes a guide which is provided at the mount and at least one of the patient module and a further module connected to the patient module.

7. An apparatus in accordance with claim 1, wherein the patient module is in the operating position after mounting onto the base module.

8. An apparatus in accordance with claim 1, wherein the base module has a device stand which is provided with a pivotal hook to hang the apparatus to the frame of a patient's bed.

9. An apparatus configured to provide an extracorporeal blood circuit, comprising:
at least one base module having a control device;
a patient module releasably connected to the base module and having blood-conducting components of the extracorporeal blood circuit disposed thereon; and
pivot means that are provided at one of the base module and the patient module for pivoting the patient module relative to the base module about a horizontal axis from a filling position into an operating position, the blood-conducting components comprising a blood reservoir, a centrifugal pump head, an oxygenator, and a filter, said blood-conducting components being mounted on the patient module to be pivotable together therewith, the patient module being configured to conduct a priming liquid through the blood-conducting components of the patient module in the filling position and to conduct blood through the blood-conducting components of the patient module in the operating position;
wherein the centrifugal pump head has a central inlet and a tangential outlet and is arranged in the patient module such that the inlet is oriented vertically upwardly in the filling position and horizontally in the operating position and the outlet is arranged at the bottommost position of the centrifugal pump head in the operating position.

10. An apparatus in accordance with claim 9, further comprising a pump configured to pump the priming liquid through the blood-conducting components in the filling position and to pump the blood through the blood-conducting components in the operating position.

11. An apparatus in accordance with claim 9, wherein the pump is disposed on the patient module.

12. An apparatus in accordance with claim 9, further comprising venting lines configured to allow air bubbles that cannot escape from the blood-conducting components of the patient module when in the filling position to escape when the patient module is in the operating position.

13. A heart-lung machine comprising the apparatus recited in claim 9.