Fluid delivery system and sensing unit therefor

• US 8,016,798 B2
• Filed: 03/09/2004
• Issued: 09/13/2011
• Est. Priority Date: 02/24/2003
• Status: Active Grant

• Current Assignee: Integrated Sensing Systems Incorporated
• Original Assignee: Integrated Sensing Systems Incorporated
• Inventors: Najafi, Nader, Sparks, Douglas Ray
• Primary Examiner(s): Stigell; Theodore
• Assistant Examiner(s): GRAY, PHILLIP A
• Application Number:
  US10/708,509
• Publication Number:
  US 20040171983A1
• Time in Patent Office: 2,744 Days
• Field of Search: 604/246, 604/131, 6048901-8921, 604 65- 67, 604533-284
• US Class Current: 604/246
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/16827 controlling delivery of multiple fluids, e.g. sequencing, mixing or via separate flow-paths infusion of multiple fluids without using a controller A61M5/1407
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: G01F 1/8445 micromachined flowmeters
• CPC Class Codes: G01F 1/8472 having curved measuring conduits, i.e. whereby the measuring conduits' curved center line lies within a plane G01F1/8481 takes precedence
• CPC Class Codes: G01F 13/006 measuring volume in function of time
• CPC Class Codes: G16H 20/17 delivered via infusion or injection

Abstract

A fluid delivery system capable of delivering a precise amount of fluid, such as a fluid required for medical treatment. The delivery system makes use of an inline sensing unit that includes a housing comprising an inlet for receiving a fluid from a fluid source, an outlet for discharging the fluid from the housing, and at least one cavity between the inlet and the outlet. A sensing element and electronic circuitry are disposed within the at least one cavity. The electronic circuitry is adapted to produce an electrical output based on at least one response of the sensing element. The sensing unit is further equipped with a communication element for providing communication between the electronic circuitry and an electronic device remote from the housing.

Claims

1. An infusion system comprising:

an intravenous pole;

an intravenous tube hanging alongside the intravenous pole;

an inline sensing unit coupled to the intravenous tube and comprising a housing, an inlet for receiving a fluid from the intravenous tube, an outlet for discharging the fluid from the housing, at least one cavity between the inlet and the outlet, and a sensing element mounted within the at least one cavity, the sensing element having a first response to the density of the fluid flowing between the inlet and the outlet of the housing, the sensing element having a second response to the mass flow rate of the fluid flowing between the inlet and the outlet of the housing;

a module attached to the intravenous pole, the module comprising electronic circuitry that produces an electrical output based on at least one of the first and second responses of the sensing element, means for displaying a visual output based on the electrical output of the electronic circuitry, means for producing an audible output based on the electrical output of the electronic circuitry;

at least one of means for detecting gas bubbles within the fluid, means for detecting a phase within the fluid, and means for determining the fluid based on the density output of the electronic circuitry; and

means for providing communication between the sensing unit and the module;

wherein the sensing element comprises;

a freestanding tube portion through which the fluid flows;

means for vibrating the freestanding tube portion at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the resonant frequency of the freestanding tube portion being the first response of the sensing element, the Coriolis effect causing the freestanding tube portion to twist to a degree that varies with the mass flow rate of the fluid flowing therethrough while the freestanding tube portion is vibrated at resonance, the degree of twist being the second response of the sensing element; and

means for sensing movement of the freestanding tube portion to sense the resonant frequency and the degree of twist of the freestanding tube portion as the fluid flows therethrough.

2. The infusion system according to claim 1, wherein the module does not contain components that contact the fluid, the sensing unit constitutes a separable disposable portion of the infusion system, and the module constitutes a reusable portion of the infusion system.

3. The infusion system according to claim 1, further comprising means in communication with the module for stopping flow of the fluid through the intravenous tube in response to the electrical output of the electronic circuitry.

4. The infusion system according to claim 1, further comprising a computer remote from the module and coupled to the module for communication therewith.