Device for extracorporeal blood treatment

1. A medical pump system comprising:

a disposable cassette having a pump; and

a reusable apparatus having a drive device configured to cooperate with the pump of the disposable cassette,

wherein the drive device includes a floating shaft having a rotational axis rotatably driven by a drive means, the drive means configured to be coupled to a motor rotor having a motor axis of the reusable apparatus,

wherein the floating shaft includes a cavity inside which the drive means is at least partially circumscribed,

wherein the drive means includes a body configured to cooperate with internal walls of the cavity to limit an orientational freedom of the rotational axis of the floating shaft relative to the motor axis to compensate for tolerance errors of the pump, and

wherein the cavity includes a cooperation element allowing the drive means to apply a rotation movement to the floating shaft.

2. The medical pump system as claimed in claim 1 , wherein the body of the drive means includes smooth rounded edges and the cavity includes smooth walls.

3. The medical pump system as claimed in claim 1 , wherein the drive means includes a longitudinal shaft, and the floating shaft includes an additional cavity extending along the floating shaft, the longitudinal shaft located inside the additional cavity to limit lateral movements of the floating shaft.

4. The medical pump system as claimed in claim 1 , wherein the drive means includes a transversal shaft, and the cooperation element includes two hard elements,

wherein the transversal shaft is configured to engage with the two hard elements of the cooperation element for applying the rotational movement.

5. The medical pump system as claimed in claim 4 , wherein at least one of the hard elements of the cooperation element and the transversal shaft of the drive means is made of a composition including an element selected from the group including cobalt, tungsten, vanadium, chromium, manganese, nickel, titanium, germanium, gallium, bismuth, indium, lithium, magnesium, molybdenum, strontium, rubidium, and palladium.

6. The medical pump system as claimed in claim 1 , wherein the internal walls of the cavity are configured to cooperate with external walls of the body of the drive means to allow the floating shaft to move linearly relative to the drive means.

7. The medical pump system as claimed in claim 1 , wherein the internal walls of the cavity are configured to cooperate with external walls of the body to allow the rotational axis of the floating shaft to undergo pitching movements relative to motor axis between +/−10°.

8. The medical pump system as claimed in claim 1 , wherein the internal walls of the cavity are configured to cooperate with external walls of the body of the drive means to allow the rotational axis of the floating shaft to undergo pitching movements relative to the motor axis between +/−5°.

9. The medical pump system as claimed in claim 1 , wherein the internal walls of the cavity includes a cone shape having a cone angle of between 0° and 90°.

10. The medical pump system as claimed in claim 1 , wherein the internal walls of the cavity includes a cone shape having a cone angle of between 5° and 30°.

11. The medical pump system as claimed in claim 1 , wherein the pump includes a peristatic pump including a flexible tube and a roller, the floating shaft configured to operationally engage with the roller of the peristaltic pump.

12. The medical pump system as claimed in claim 11 , wherein the roller includes a flexible part configured to cooperate with the floating shaft.

13. The medical pump system as claimed in claim 1 , wherein the floating shaft includes a rigid assembly having base and a cover, the cover forming the cavity.

14. The medical pump system as claimed in claim 1 , wherein the drive means includes a transversal shaft, and the internal walls of the cavity include two walls arranged above and below the transversal shaft, the two walls having a conical shape.

15. A medical pump system comprising:

a disposable cassette having a pump; and

a reusable apparatus having a drive device configured to cooperate with the pump of the disposable cassette,

wherein the drive device includes a floating shaft having a rotational axis rotatably driven by a drive means, the drive means configured to be coupled to a motor rotor having a motor axis of the reusable apparatus,

wherein the floating shaft includes a cavity inside which the drive means is at least partially circumscribed,

wherein the drive means includes a body configured to cooperate with internal walls of the cavity to limit an orientational freedom of the rotational axis of the floating shaft relative to the motor axis to compensate for tolerance errors of the pump, and

wherein the internal walls of the cavity are configured to cooperate with external walls of the body to allow the rotational axis of the floating shaft to undergo pitching movements relative to motor axis between +/−10°.

16. A medical pump system comprising:

a disposable cassette having a pump; and

a reusable apparatus having a drive device configured to cooperate with the pump of the disposable cassette,

wherein the drive device includes a floating shaft having a rotational axis rotatably driven by a drive means, the drive means configured to be coupled to a motor rotor having a motor axis of the reusable apparatus,

wherein the floating shaft includes a cavity inside which the drive means is at least partially circumscribed,

wherein the drive means includes a body configured to cooperate with internal walls of the cavity to limit an orientational freedom of the rotational axis of the floating shaft relative to the motor axis to compensate for tolerance errors of the pump, and

wherein the internal walls of the cavity includes a cone shape having a cone angle of between 0° and 90°.