US 8,708,961 B2 · Apparatus for infusing liquid to a body

Abstract

An infusion device having a housing with a reusable control portion and an expendable reservoir portion includes a precise drive for an infusion pump. The drive includes a piezoelectric bender assembly, a limiter and at least one contact stop. The piezoelectric bender assembly includes a cantilevered piezoelectric bender having an member of predetermined thickness fixed to move with the second end. A limiter of dimensionally stable material including a gap and at least a first mounting hole extending to the gap. The member of predetermined thickness extends into the gap. A first contact stop is positioned in the gap to define a critical gap distance limiting movement of the member of predetermined thickness in the gap. A base has a mounting surface, a port through the base and extending to the mounting surface. The port includes a first length having a smaller diameter at the mounting surface and a second length displaced from the mounting surface and having a larger diameter. A rigid cannula extends from the base through the port. The rigid cannula has a diameter smaller than the smaller diameter of the port, and the first length of the port has an annular open gap for lateral or pivotal movement of the rigid cannula. A mount of elastomeric material in the length having the larger diameter mounts the rigid cannula. The cannula includes hydrogel material in a desiccated state coating the surface of the cannula, including the beveled end, which rehydrates upon placement in the patient.

Claims25

Dependent claims

An infusion device, comprising

a housing including a control portion and a reservoir portion separable from the control portion;
a precise drive including a piezoelectric bender assembly having a piezoelectric bender with a first end fixed relative to the control portion and a second end movable relative to the first end, a limiter fixed to the control portion including a first limiter end having a rest stop and a second limiter end having an actuator stop, the rest stop and the actuator stop defining a dimensionally stable limiter gap, the piezoelectric bender assembly extending into the limiter gap to define a stroke gap between the limiter and the piezoelectric bender assembly in the limiter gap, and a resilient device biased against the piezoelectric bender assembly to move with the piezoelectric bender assembly and having a resilient stroke greater than the stroke gap, the resilient device acting in opposition to the bender assembly with the bender assembly exhibiting greater force than the resilient device when the bender assembly is electrified, the piezoelectric bender assembly being capable of a stroke which is greater than the stroke gap allowed by the limiter;
a pump including a cylinder and a piston capable of reciprocation in the cylinder, the piston engaged to move with the resilient device, the resilient device and the pump being in the reservoir portion.

An infusion device, comprising

a housing including a control portion and a reservoir portion separable from the control portion;
a precise drive mounted in the control portion and including a piezoelectric bender assembly having a piezoelectric bender with a first end fixed to the control portion and a second end movable relative to the first end and a limiter including two limiter ends and two elements at the ends, respectively, defining a dimensionally stable limiter gap there between, the limiter being fixed to the control portion, the piezoelectric bender assembly extending into the limiter gap to define a stroke gap between the limiter and the piezoelectric bender assembly in the limiter gap, the piezoelectric bender assembly being capable of a stroke which is greater than the stroke gap allowed by the limiter;
a pump mounted in the reservoir portion, the pump including a cylinder, a piston capable of reciprocation in the cylinder and engaged to move with the piezoelectric bender assembly, a resilient diaphragm having a periphery fixed relative to the reservoir portion and a central portion against which the piezoelectric bender assembly is in contact, the piston being attached to the central portion of the resilient diaphragm and extending away from the piezoelectric bender assembly.

Dependencies are inferred from the claim text.

Apparatus for infusing liquid to a body

Life of this patent

Apparatus for infusing liquid to a body

Life of this patent

Abstract

Claims25