News Column

Patent Application Titled "Tube Roller Pump Including a Pivotable Tube Support and Medical Device for Extracorporeal Blood Treatment" Published Online

January 30, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors Schaefer, Oliver (Neuenstein, DE); Iske, Andreas (Melsungen, DE); Broeker, Bjoern (Staufenberg, DE), filed on July 2, 2013, was made available online on January 16, 2014.

No assignee for this patent application has been made.

Reporters obtained the following quote from the background information supplied by the inventors: "In medical devices for extracorporeal blood treatment (dialysis) frequently tube roller pumps are used for feeding the collected blood of the patient to a dialyser and back to the patient. Said tube roller pumps function as peristaltic pumps, wherein a loop-shaped tubing segment is adjacent to an appropriately bent bearing surface of the pump housing. A rotor of the pump located inside the bearing surface then moves with its outer edges along the tubing segment, wherein it locally impresses the tube and thus enables feeding of blood through the tubing segment by the elastic material properties of the tubing segment. For this purpose, the blood is fed to the tubing segment via a first port and is discharged again via another port at the other end of the tubing segment.

"The tubing segment thus forms a transfer system, as it is called, e.g. together with the feeding and discharging lines and several air traps, by which transfer system the blood of the patient is fed to a dialyser and back to the patient. Those transfer systems are preferably exchanged after each treatment and are not re-used for other patients. A used tubing segment thus has to be removed from the pump before a new transfer system is introduced into the device. For facilitating the handling during removal and rigging of the transfer system it is further known to provide a connector adapted to be connected to a feeding and discharging line, respectively, at each of the two ends of the tubing segment.

"For accommodating a tube inside a roller pump the patent U.S. Pat. No. 8,047,819 B2, for example, describes holding means that are detachably mounted on the pump housing. So for different sizes and types of tubes different holding means can be mounted on the pump. A holding means includes a clamping device including at least one pivoting clamp jaw having a semicircular recess so that a tube can be held in said semicircular recess and an opposed equally semicircular recess of another clamp jaw. The clamp jaws can also include plural of said recesses so that plural tubes can be simultaneously accommodated.

"Moreover automatic systems are known that are intended to take over and thus facilitate threading and unthreading of the tube into the pump. Frequently, for unthreading an actuator moving the system from its therapy position into an unthreading position via a linear drive, for instance, has to be operated. For this purpose, it can be required in those systems to operate a switch/button at the medical device or to touch a software button on user interface.

"Furthermore, multi-connectors are known which combine both terminals for feeding and discharging lines in one component part which then can be introduced into a receiving portion of the pump housing. Via the geometric shape of such multi-connectors it is possible to detect the presence thereof in the pump by the fact that during the inserting operation for instance a cylindrical portion of the multi-connector operates a plunger the axial position of which is queried via a light barrier. At the same time this plunger is part of an electromechanical actuator mounted in the pump housing which is adapted to eject the multi-connector via a linear drive.

"In order to move a tubing segment at a tube roller pump into the respective threading and unthreading position, e.g. from JP 2008-000425 several variants of a pivoting member or rocker arm are known to which both ends of the loop-shaped tubing segment can be fastened. In a first pivoting position of the rocker arm the tubing segment then is provided in a position in which the threading operation can be started while the tubing segment can be unthreaded in a different pivoting position. The automatic threading and unthreading operation is performed by guide pins at the periphery of the rotor, the guide pins pressing the tube into the pump housing or out of the latter upon rotation of the rotor.

"Both ends of the loop-shaped tubing segment are lifted and lowered, respectively, by the rocker arm so that the guide pins have to be appropriately shaped so as to be capable of catching the tube in said two positions and pressing it into a particular direction. The automatic threading and unthreading operation must be adapted to be reliably implemented, but the tube must not be deformed too strongly."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "Based on this, it is the object of the invention to provide a tube roller pump for a medical device for extracorporeal blood treatment which enables a tubing segment to be arranged so that the tubing segment can be threaded into and unthreaded from the tube roller pump in an automated manner.

"It is another object of the invention to provide a medical device for extracorporeal blood treatment comprising such tube roller pump.

"The tube roller pump according to aspects of the invention is suited for a medical device for extracorporeal blood treatment and includes a pump housing having a bent bearing surface and a rotor rotatable inside the bearing surface, wherein a tubing segment can be introduced between the bearing surface and the rotor in loop shape. According to aspects of the invention, at the pump housing a stationary first receiving portion for accommodating one end of the loop-shaped tubing segment and a rocker arm including a second receiving portion for accommodating the other end of the loop-shaped tubing segment are provided, the rocker arm being rotatable about a pivoting axis so that the second receiving portion with the tubing segment can be brought into at least two different positions and that a first position constitutes a threading position and a second position constitutes an unthreading position for the tubing segment.

"This configuration of the tube roller pump helps to arrange a tubing segment on a pump housing in a simple manner. One end of a loop-shaped tubing segment can be introduced into a receiving portion at the pump housing, the receiving portion being stationary and the tubing segment thus being fixed at the pump housing in this area. The other end of the loop-shaped tubing segment, on the other hand, is introduced into the receiving portion at the rocker arm so that the tubing segment is movable in this area. Thus this area of the tubing segment can be brought both into a threading position and into an unthreading position.

"Preferably the receiving portions are in the form of undercut recesses into which the elastic tubing segment can be pressed. In the wake of the therapy the tube can be removed from the receiving portions again.

"Furthermore means for automated threading and unthreading of the tubing segment between the rotor and the bearing surface can be provided at the rotor. For instance at the periphery of the rotor at least one guide pin is disposed which upon rotation of the rotor contacts the tube and forces the same into a specific direction. The second receiving portion is then provided in the unthreading position at a position at which the at least one guide pin moves between the tubing segment and the bottom of the pump housing upon rotation of the rotor and thus can lift the tubing segment out of the pump housing. By pivoting the rocker arm away from the pump housing the second receiving portion and thus the tubing segment is lifted so far that the at least one guide pin can unthread the tubing segment.

"In contrast to this, the second receiving portion is provided in the threading position at a position at which the at least one guide pin moves above the tubing segment upon rotation of the rotor and hereby the tubing segment can be pressed into the pump housing. By pivoting the rocker arm the tubing segment is thus moved above or below the at least one guide pin so that the latter is adapted to carry out the threading or unthreading operation.

"It is a particular advantage of the stationary first receiving portion that this receiving portion is not lifted or lowered but is fixed to the pump housing so that in this area no pinching of the tube will take place. In this way the risk of hemolysis during the therapy is reduced so that especially during the threading operation before the therapy it is important for the tube not to be badly deformed. Therefore the stationary first receiving portion preferably is the receiving portion in the direction of which the tube is slightly pushed by the at least one guide pin during threading.

"In an embodiment of the invention means for maintaining the rocker arm in the threading position are provided at the tube roller pump. For this, for example aside the pivoting axis means for locking the rocker arm with the pump housing can be provided so that the rocker arm and thus the second receiving portion with the tubing segment can be manually pivoted into the threading position by an operator and are maintained there by themselves. For this purpose, at the pump housing a stop catch forming a stop mechanism together with the geometry of the rocker arm can be formed, wherein the locking takes place in the area of the second receiving portion.

"Moreover, preferably also means for maintaining the rocker arm in the unthreading position are provided. They, too, can be realized in the form of a stop mechanism, wherein a stop catch forming a stop mechanism at the rocker arm together with a stop spring is configured at the pump housing. This stop spring can be bent and can be arranged in the area of the pivoting axis at the rocker arm, the bending of the stop spring extending substantially around the pivoting axis.

"In order to be able to detect the respective position of the rocker arm at the different position the geometry and/or the material of the rocker arm can be configured so that the rocker arm can be detected at least in the threading position and in the unthreading position directly by detecting means at the tube roller pump. As soon as these positions have been clearly detected, the automated threading and/or unthreading operation can be initiated.

"Different detecting mechanisms can be applied. For example, at the rocker arm at least one magnet and/or a ferromagnetic material is/are arranged. The plastic material of which the rocker arm is made can be injected around the magnet, for example, or the magnet is plasticized. A magnetically acting sensor system e.g. including Hall sensors at various positions then enables different positions of the rocker arm to be detected. In this embodiment of the invention, the detection is thus effected at least via the material properties of the rocker arm, because a magnetic area has to be provided; but also the geometry of the component part is crucial in order to be able to safely detect the various positions of the rocker arm. For this purpose, the magnet has to be arranged in a defined area, wherein such area may be specifically formed so as to detect the same by the sensor system.

"This applies mutatis mutandis to an embodiment of a rocker arm in which at least a ferromagnetic material is arranged at the base member and/or the connector elements. The ferromagnetic material, too, can be surrounded by injection of plastic material, for example. It is possible in this way to detect different positions of the rocker arm by an inductively acting sensor system, with the detection being performed by way of the geometry and the material properties.

"The different positions can also be detected. In another embodiment of the invention the rocker arm is opaque or light dispersive in at least one area, for example, and a transparent breakout is provided adjacent to the area or within the area. The rocker arm can be transparent outside the opaque or light dispersive area or the entire rocker arm is designed to be an opaque or light dispersive area. In this embodiment of the invention, the rocker arm position is detected via the geometry and the material properties of the rocker arm, these properties being used for an optical detection.

"In such configuration of a rocker arm it is possible, for example, to determine by at least one light barrier in which position the rocker arm is just provided, for the light of a light barrier is either interrupted, when it is incident on an opaque or light dispersive area, or can penetrate the base member in the area of the breakout. An at least partly transparent rocker arm has the advantage that light cannot only be guided through the same in order to be detected by a light barrier. Rather, the position of the transmitting diodes of the light barrier can also be selected more freely, for there is the possibility that the light of a light barrier first penetrates a transparent partial area of the rocker arm, before it impinges on a breakout or an opaque or light dispersive area. This facilitates the configuration of the sensor system at the pump housing.

"In another embodiment of the rocker arm the geometry and the material of the rocker arm form a light conductor through which the light is conductive along a defined path through the rocker arm. The light conductor preferably is configured so that light is conductive from the pivoting axis through the rocker arm to the second receiving portion. By appropriately arranging at least one transmitting diode that couples light into the rocker arm and at least one receiving diode that receives light out of the rocker arm different positions of the rocker arm can be detected by means of a sensor system by appropriately arranging the diodes in the different positions.

"Furthermore, the invention includes a medical device for extracorporeal blood treatment comprising at least a tube roller pump including a pump housing having a bent bearing surface and a rotor rotating inside the bearing surface, wherein a tubing segment of an extracorporeal blood circulation can be introduced between the bearing surface and the rotor and blood can be fed to the tubing segment via a feeding line, while blood can be discharged from the tubing segment via a discharging line. In accordance with the invention, the device comprises a tube roller pump according to one of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

"The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings are the following figures:

"FIG. 1 a schematic representation of a medical device for extracorporeal blood treatment with a blood pump;

"FIG. 2 a schematic top view on a tube roller pump including an inserted tubing segment;

"FIG. 3 a schematic side view of a tube roller pump according to FIG. 2 upon inserting a tubing segment;

"FIG. 4 a schematic side view of a tube roller pump according to FIG. 3 upon pressing the rocker arm into the stop mechanism;

"FIG. 5 a schematic side view of a tube roller pump according to FIG. 3 with a closed cover in the threading position;

"FIG. 6 a schematic side view of a tube roller pump according to FIG. 3 with a closed cover in the unthreading position;

"FIG. 7a an enlarged view of the stop mechanism in the area of the pivoting axis in the unthreading position; and

"FIG. 7b an enlarged view of the stop mechanism in the area of the pivoting axis in the threading position."

For more information, see this patent application: Schaefer, Oliver; Iske, Andreas; Broeker, Bjoern. Tube Roller Pump Including a Pivotable Tube Support and Medical Device for Extracorporeal Blood Treatment. Filed July 2, 2013 and posted January 16, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=2787&p=56&f=G&l=50&d=PG01&S1=20140109.PD.&OS=PD/20140109&RS=PD/20140109

Keywords for this news article include: Patents, Therapy, Hemolysis, Treatment, Risk and Prevention.

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Source: Politics & Government Week


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