Device and method for fluid dynamics cleaning of constrained spaces
A method for cleaning interior surfaces of a header region of a hemodialyzer includes steps of: introducing an insertion device having an end portion and a shaft through a hemodialyzer plug port so that the end portion of the insertion device is within the header region; rotating the shaft at a speed sufficient to generate mechanical stresses for the removal of contaminants from interior surfaces of the header region; removing the insertion device from the header region; and rinsing and flushing away the removed contaminants from the header region. An apparatus and an insertion device for cleaning a header region of a hemodialyzer are disclosed.
1. A method for cleaning interior surfaces of a header region of a hemodialyzer defined by a header surface and a header region wall, the method comprising:
(a) introducing an insertion device having an end portion and a shaft through a hemodialyzer blood port so that the end portion of the insertion device is within the header region, wherein the shaft has a bend so that the end portion extends toward the header region wall forming a tip gap between the end portion and the header region wall, and forming a main gap between the shaft and the header surface;
(b) rotating the shaft at a speed sufficient to generate mechanical stresses for the removal of contaminants from interior surfaces of the header region;
(c) removing the insertion device from the header region; and
(d) rinsing and flushing away the removed contaminants from the header region.
2. A method according to claim 1 wherein the header region includes liquid sufficient to cover the end portion of the insertion device during rotation.
3. A method according to claim 1 wherein the end portion comprises a non-abradable polymer.
4. A method according to claim 1 wherein the end portion is a hydrophobic polymer.
5. A method according to claim 1 wherein the end portion is smooth.
6. A method according to claim 1 wherein the rotational speed is more than 100 rpm.
7. A method according to claim 1 wherein the rotational speed is between 5,000 and 15,000 rpm.
8. A method according to claim 1 wherein the contaminants comprise blood clots.
9. A method according to claim 1 wherein the contaminants comprise patient materials.
10. A method according to claim 1 wherein at least a portion of the contaminants is removed by attachment to the rotating end portion.
11. A method according to claim 1 wherein the insertion device forms a narrow gap relative to the header surface during rotation.
12. A method according to claim 11 wherein the shear stresses generated in the gap between the header surface and the end portion of the insertion device is higher than outside the gap.
13. A method according to claim 1 wherein the rotation speed generates a shear stress of at least 3 Pa.
14. A method according to claim 1 wherein the rotation speed generates a shear stress of more than 10 Pa.
15. A method according to claim 1 wherein the rotation speed generates a shear stress more than 14 Pa.
16. A method according to claim 1 wherein the header region includes a sufficient volume of liquid to generate hydrodynamic shear stresses.
17. A method according to claim 1 wherein the end portion is shaped to form a narrow gap with most of the header surface.
18. A method according to claim 1 wherein the end portion length is sufficient to generate shear stress at the periphery of the header region during rotation.
19. A method according to claim 1 wherein the stiffness of the end portion is high enough to prevent deflection during rotation.
20. A method according to claim 1 wherein the axial force applied to the end portion is enough to form a narrow main gap with the header surface.
21. A method according to claim 1 wherein the axial force applied to the end portion is adjusted to prevent contact of the flexible member with the header surface.
22. A method according to claim 1 wherein the cleaning time is at least 5 seconds.