PERISTALTIC PUMP

• US 20120020822A1
• Filed: 07/21/2011
• Published: 01/26/2012
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Aperia Technologies, Inc.
• Original Assignee: Aperia Technologies, Inc.
• Inventors: Richardson, Brandon, Carter, Joshua
• Granted Patent: US 8,747,084 B2
• Time in Patent Office: Days
• US Class Current: 417/477.2
• CPC Class Codes: F04B 43/1238 using only one roller as the squeezing element, the roller moving on an arc of a circle during squeezing

Abstract

A peristaltic pump system including an arcuate pressing surface, a force element that applies an occluding force towards the pressing surface, a drive mechanism that drives the force element, a diaphragm disposed between the pressing surface and the force element that defines a pump cavity, an actuator strip disposed between the diaphragm and the force element that receives the occluding force, deflects to deform the diaphragm, and occludes the pump cavity, a support structure that retains the actuator and diaphragm positions relative to the pressing surface, and a restitution mechanism that recovers the open pump cavity configuration.

Claims

1. A peristaltic pump system comprising:

a planetary rotor sub-system, including;

a rotor;

a ring defining a pressing surface along the inner bearing surface, the pressing surface defining a groove along a circumferential section, wherein the groove has a substantially well-shaped cross section; and

a planetary roller element, driven by relative motion between the pressing surface and the rotor, wherein the roller element rolls along the pressing surface and applies an occluding force against the pressing surface;

an occlusion sub-system including;

a diaphragm sheet that seals the groove opening, defining a deformable volume in conjunction with the groove, wherein the deformable volume is operable between;

an open configuration, wherein the deformable volume is unoccluded; and

an occluded configuration, wherein the deformable volume is occluded;

an actuator strip, disposed between the roller element and the diaphragm, that biases the deformable volume to recover the open configuration, the actuator strip having a having a butte-shaped cross-sectional profile with a narrow occluding surface, a wide bearing surface, and radiused side walls, wherein the occluding surface is coupled to the diaphragm along the longitudinal centerline of the diaphragm, and the bearing surface couples to the roller element; and

a support structure including;

a diaphragm restraint portion that clamps the diaphragm edges against the pressing surface of the ring; and

an actuator restraint portion, disposed along the longitudinal edges of the actuator bearing surface, that limits the deflection of the actuator away from the pressing surface;

wherein the actuator strip is held in tension against the actuator restraint portion to bias the deformable volume in an open configuration;

wherein the occlusion system is operable in three modes;

a rest mode, wherein the deformable volume achieves the open configuration;

an occluded mode, wherein the rolling element applies an occluding force to a localized section of the bearing surface, deflecting the actuator strip such that the occluding surface deforms the diaphragm, occluding the corresponding section of the deformable volume; and

a pressurized mode, wherein the pressure within the deformable volume is higher than ambient pressure, wherein the actuator restraint portion prevents actuator deflection, preventing diaphragm expansion, maintaining the volume of the deformable volume and maintaining the pressure within the deformable volume.

2. The system of claim 1, wherein the pressing surface rotates and the angular position of the rotor of the planetary rotor mechanism is held substantially static.

3. The system of claim 1, wherein the diaphragm is held in radial tension along the diaphragm thickness.

4. The system of claim 3, wherein the diaphragm sheet is a circular band, wherein the diaphragm is radially stretched over a circular support structure to achieve radial tension.

5. The system of claim 1, wherein the occlusion system generates a suction force when shifting from occluded mode to rest mode.

6. A peristaltic pump system comprising:

an arcuate pressing surface;

a force element that translates along the pressing surface and applies an occluding force towards the pressing surface;

a drive mechanism that facilitates force element translation;

a diaphragm, disposed between the force element and the pressing surface, that defines a pump cavity, wherein the pump cavity is operable between an open configuration and an occluded configuration;

an actuator strip, disposed between the force element and the diaphragm, wherein the actuator strip is longitudinally aligned with the diaphragm, the actuator strip including;

an occluding surface that couples to the diaphragm and has a profile that minimizes diaphragm deformation stress; and

a bearing surface that receives the occluding force from the force element and transmits the occluding force to the occluding surface;

wherein the force element deforms successive localized segments of the actuator strip, which deform successive sections of the diaphragm to occlude the corresponding segments of the deformable volume;

a support structure including;

a diaphragm restraint portion that couples the longitudinal edge of diaphragm against the pressing surface of the ring; and

an actuator restraint portion, disposed along the longitudinal edges of the actuator bearing surface, that couples the actuator to the pressing surface and limits the deflection of the actuator away from the pressing surface;

a restitution mechanism that recovers the open configuration of the pump cavity.

7. The system of claim 6, wherein the width of a gap formed along each longitudinal edge between the actuator and the support structure is controlled.

8. The system of claim 6, wherein the force element is a roller element.

9. The system of claim 8, wherein the drive mechanism is a planetary rotor system, wherein the roller element is a planetary roller and the pressing surface is the ring surface.

10. The system of claim 9, wherein rotation of the pressing surface drives roller element rotation.

11. The system of claim 6, wherein the pressing surface further includes a groove along the longitudinal centerline of the pressing surface.

12. The system of claim 11, wherein the pressing surface is concave.

13. The system of claim 11, wherein the groove has a substantially butte-shaped profile.

14. The system of claim 11, wherein the diaphragm substantially seals the groove opening to define the pump cavity.

15. The system of claim 14, wherein the diaphragm is a flexible sheet of substantially uniform thickness.

16. The system of claim 15, wherein the diaphragm is raised along the longitudinal centerline, such that the diaphragm has a substantially bell-shaped cross section.

17. The system of claim 11, wherein the profile of the occluding surface compliments the body and edges of the groove.

18. The system of claim 6, wherein the diaphragm is a tube with an amygdaloidal cross section.

19. The system of claim 6, wherein the restitution mechanism disposes the actuator in radial tension toward the actuator restraint.

20. The system of claim 19, wherein the actuator is stretched over the actuator restraint during assembly.

21. The system of claim 19, wherein the actuator is coupled to the diaphragm, such that the actuator tension recovers the open configuration of the pump cavity.

22. The system of claim 6, wherein the support structure clamps the diaphragm longitudinal edges to the pressing surface.

23. The system of claim 6, wherein the actuator restraint includes a pair of flanges, disposed along the longitudinal edges of the bearing surface, that prevent actuator deflection past a predetermined distance away from the pressing structure.