Infusion apparatus with constant force spring energy source
A fluid dispenser for use in controllably dispensing fluid medicaments, such as antibiotics, oncolytics, hormones, steroids, blood clotting agents, analgesics, bio-pharmaceuticals and like medicinal agents from a reservoir that has been filled from pre-filled containers. The fluid dispenser includes a housing to which fill-vials can be connected for filling the dispenser reservoir with the fluid, and a stored energy source provided in the form of a substantially constant-force spring that provides the force necessary to continuously and uniformly expel fluid from the device reservoir. The fluid dispenser also includes a fluid flow control assembly that precisely controls the flow of the medicament solution to the patient.
1. A dispensing apparatus for dispensing fluids to a patient comprising:
(a) an outer housing having first and second portions, said second portion having a cavity;
(b) an expandable housing disposed within said second portion of said outer housing, said expandable housing having a fluid reservoir provided with an inlet for permitting fluid flow into said fluid reservoir and an outlet for permitting fluid flow from said fluid reservoir, said expandable housing comprising a bellows structure having an accordion-like side wall movable from a substantially collapsed configuration to a substantially expanded configuration by fluid flowing into said fluid reservoir;
(c) stored energy means disposed within said second portion of said outer housing for exerting a force upon said inner expandable housing to cause the fluid contained within said fluid reservoir to controllably flow through said outlet, said stored energy means comprising an expandable, contractible constant force spring carried within said outer housing;
(d) fill means carried by said first portion of said outer housing for filling said reservoir with the fluid to be dispensed, said fill means comprising a pierceable septum disposed within said cavity in said housing;
(e) dispensing means carried by said outer housing for dispensing fluid to the patient; and
(f) flow control means connected to said outer housing for controlling fluid flow between said reservoir and said dispensing means, said flow control means comprising a flow control assembly, including an inlet manifold having an inlet port in communication with said fluid reservoir and an outlet port, a plurality of adjacent, fixedly connected plates, each having a planar surface and an inlet in communication with said outlet port of said inlet manifold, a plurality of flow rate control plates each having a micro-channel formed therein; said planar surfaces of said flow rate control plates cooperating with said planar surfaces of said adjacent places having a micro-channel formed therein to form a plurality of fluid flow control channels, each said flow control channel having an outlet in communication with said dispensing means; and
(g) selector means carried by said first portion of said outer housing for selectively bringing a selected one of said flow control channels into communication with said dispensing means.
2. A dispensing apparatus for dispensing fluids to a patient comprising:
(a) an outer housing having first and second portions, said second portion having a cavity;
(b) an expandable housing disposed within said second portion of said outer housing, said expandable housing having a fluid reservoir provided with an inlet for permitting fluid flow into said fluid reservoir and an outlet for permitting fluid flow from said fluid reservoir, said expandable housing comprising a bellows structure having an accordion-like side wall movable from a substantially collapsed configuration to a substantially expanded configuration by fluid flowing into said fluid reservoir;
(c) stored energy means disposed within said outer housing for exerting a force upon said first expandable housing to cause the fluid contained within said fluid reservoir to controllably flow through said outlet, said stored energy means comprising a constant force extension spring carried within said outer housing, said constant force extension spring comprising a coiled strip of pre-stressed material that exerts a nearly constant restraining force to resist uncoiling, said constant force spring being retractable to cause fluid flow from said reservoir;
(d) fill means carried by said first portion of said outer housing for filling said reservoir with the fluid to be dispensed, said fill means comprising a pierceable septum disposed within said cavity in said housing;
(e) dispensing means carried by said outer housing for dispensing fluid to the patient said dispensing means comprising an administration set;
(f) flow control means connected to said outer housing for controlling fluid flow between said reservoir and said dispensing means, said flow control means comprising a flow control assembly, including a plurality of adjacent non-rotatable, fixedly connected flow rate control plates each having a planar surface and a central inlet in communication with said reservoir and selected ones of said rate control plates having a micro-channel formed therein, said flow control plates cooperating to form a plurality of flow channels each having an outlet in communication with said dispensing means; and
(g) selector means carried by said first portion of said outer housing for selectively bringing a selected one of said flow control channels into communication with said dispensing means.