Fluid flow control system

• US 4,778,450 A
• Filed: 06/06/1986
• Issued: 10/18/1988
• Est. Priority Date: 07/12/1979
• Status: Expired due to Fees

• Current Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Original Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Inventors: Kamen, Dean L.
• Primary Examiner(s): Coven, Edward M.
• Assistant Examiner(s): Reichle, K. M.
• Application Number:
  US06/871,714
• Time in Patent Office: 865 Days
• Field of Search: 128/DIG. 13, 604/65, 604/67, 604/246, 604/247, 604/248, 604/249, 604/250, 222/58, 222/59
• US Class Current: 604/65
• CPC Class Codes: A61M 5/16895 by monitoring weight change, e.g. of infusion container
• CPC Class Codes: G01G 17/06 having means for controlling the supply or discharge
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

In a fluid flow control system a weight comparator compares the weight of fluid in a reservoir with a weight reference that is programmed to decrease at a desired rate. A fluid flow comparator compares the actual fluid flow rate with a programmed fluid flow rate and operates directly on a flow controller to control fluid flow in the system. The weight comparator operates indirectly on the flow controller by recurringly updating the programmed fluid flow rate so that flow is controlled on a current basis by the fluid flow comparator and on a long-term basis by the weight comparator.

Claims

1. A system for controlling in a desired manner the flow of fluid in a line from a reservoir to a patient, the system comprising:

weight measurement means for mesuring the weight of fluid in the reservoir and producing a weight measurement signal;

weight reference means for providing a weight reference signal that is programmed to decrease at a desired rate;

weight comparison means for comparing the weight measurement signal with the weight reference signal and for producing an output indicative of the dissimilarity between the two signals;

flow controller means for regulating the fluid flow in the line from the reservoir;

fluid flow measurement means, placed in the line of flow from the reservoir, for determining the fluid flow rate and producing an actual fluid flow rate signal;

programmed fluid flow rate means, in communication with the output of the weight comparison means, for providing a programmed fluid flow rate signal that is recurringly updated on the basis of the output of the weight comparison means;

fluid flow comparison means for comparing the actual fluid flow rate signal with the programmed fluid flow rate signal, and for producing an output indicative of the dissimilarity between the two signals, the fluid flow comparison means being directly operative on the flow controller means;

whereby the fluid flow rate is directly controlled by the dissimilarity between the actual fluid flow rate and the programmed fluid flow rate and the programmed fluid flow rate signal is recurringly updated by the weight comparison means, so that the flow rate of fluid is ultimately controlled by the weight reference means.

2. A system according to claim 1, wherein the flow controller means is a pump.

3. A system according to claim 1, wherein said weight measurement means is an electrical means, said weight reference means is an electrical means, and fluid flow measurement means is an electrical means.

4. A system according to claim 3, wherein the flow controller means is a pump.