Magnetically balanced finger-type peristaltic pump

Inventors

Rotem, Shachar • Goldor, Ori

Assignees

Eitan Medical Ltd

Abstract

A peristaltic pump includes a plurality of effecters, actuated in a periodic manner upon by obstructive forces of a flexible infusion tube so as flow of infusion fluid is provided along said infusion tube, the magnitude of the obstructive forces being dependent upon the displacement of said moving effecters; and a plurality of balancing magnets providing balancing forces upon one or all the moving effecters, the balancing forces at each point along the path of motion of the moving effecters being of approximately equal magnitude to that of the obstructive forces at the point; such that the parasitic output due to work performed against the obstructive forces is approximately zero and yield is maximized.

Core Innovation

The invention describes a peristaltic pump with a channel to receive a flexible tube and at least one effecter that intermittently compresses the tube within the channel, where compression of the tube produces a reactive force. At least one electrically triggerable actuator applies a mechanical force to the effecter to drive periodic finger actuation against the flexible infusion tube and generate obstructive forces that depend on finger displacement.

A balancing member magnetically interacts with a metal member in the effecter so that a balancing force proportional to the mechanical force on the effecter is produced to substantially counter the reactive force of the tube. In operation, balancing magnets apply balancing forces approximately equal to the obstructive forces along the motion path, so parasitic work output is substantially reduced to approximately zero, thereby maximizing yield and efficiency.

The disclosure further addresses adaptive cam concepts and cam profiles that cooperate with the effecters to obtain complete shutoff under worn and tolerant tube conditions and to maintain sealing behavior during the finger motion. Force-cycle behavior is discussed in terms of points along the cycle where total cam-to-finger force is near zero and where magnet forces can exceed elastic tube forces to ensure sealing, including cam forms such as crescent forms and related compliance-zone radius reduction concepts.

Claims Coverage

The provided claims include one independent claim that defines the overall magnetically balanced peristaltic pump architecture. Dependent claims refine effecter and magnetic interaction characteristics, including forward and backward balancing behavior and specific magnetic-field interactions.

Overall claim coverage centers on intermittently compressing a flexible tube using electrically triggerable effecters and substantially counteracting the tube’s reactive force with a magnetically produced balancing force proportional to the actuator force. Dependent claims refine the effecter structure, specify material pairings for magnetic interaction, restrict balancing to forward and backward movement, and characterize the balancing member as producing a permanent magnetic field and/or being attracted to a magnetic field.

Stated Advantages

Documented Applications