Flow control for an intravenous feeding system

• US 4,137,915 A
• Filed: 06/03/1977
• Issued: 02/06/1979
• Est. Priority Date: 06/03/1977
• Status: Expired due to Term

• Current Assignee: Dean Kamen
• Original Assignee: Dean Kamen
• Inventors: Kamen, Dean
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/803,073
• Time in Patent Office: 613 Days
• Field of Search: 128/214 R, 128/214 E, 128/214 F, 128/214.2, 128/DIG. 12, 128/DIG. 13, 340/272, 222/58, 200/85 R
• US Class Current: 604/65
• CPC Class Codes: A61M 5/16895 by monitoring weight change, e.g. of infusion container
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

The flow control hereof is applied to a known system of feeding a patient intravenously and contemplates the use of a clamp applied externally to the delivery tube extending from the intravenous bag, bottle or other appropriate container to the patient, said clamp being selectively successively opened and then closed to correspondingly meter the feeding flow of the intravenous fluid on a selected volume per time basis, e.g. 1 cc/minute, so that intravenous feeding of the patient is achieved according to a desired time schedule. The external application of the clamp does not detract from conventional sterile conditions of the system. Also, and most important, the operation of the clamp is related to the weight of the intravenous fluid, which weight, if the feeding is proceeding as it should, should progressively diminish in a predictable way. The flow control hereof thus allows uninterrupted flow if the weight is not diminishing at the rate that it should; or it terminates flow, if the rate is too rapid. In this effective way, the flow control hereof thus correspondingly effectively supervises the intravenous feeding so that it is achieved according to a desired time schedule.

Claims

1. A flow control for dispensing fluid intravenously to a patient through a system including an elevated container of a supply volume of fluid and having a flexible hose connected from said container to said patient, said flow control comprising an electrically-operated clamp mounted in normally closed relation on said flexible hose so as to prevent flow therethrough, a clamp-control circuit having a movable switch arm and a cooperating switch contact electrically connected to open said normally closed clamp whenever there is physical contact established between said movable switch arm and said switch contact, a cooperating pair of movement-urging means operatively connected to said switch arm in opposing relation to each other so as to position said switch arm in relation to said switch contact as a function of an overbalance in the urgency of one said means over the other, one said movement-urging means being a spring operatively connected to normally bias said switch arm in ascending movement into a clearance position above said switch contact, the other said movement-urging means being said container of said supply volume of fluid operatively connected to normally bias said switch arm in descending movement into contact with said switch contact, a motor having a threaded rotor depending therefrom serving as a support means for said spring, said threaded rotor having a nut threadably disposed thereon and said spring being connected in a depending supported position from said nut such that in response to rotation of said threaded rotor said nut is either raised or lowered therealong to correspondingly either raise or lower said spring connected thereto, and a timer operatively connected to cause rotational operation of said motor so as to correspondingly cause rotation of said threaded rotor in relation to said nut to successively cause descending movement in said spring and thus also corresponding descending movement in said switch arm connected thereto, whereby a cycle of operation of said flow control includes a first occurring descent in said switch arm which opens said clamp and contributes to flow through said hose emptying said container of fluid and causing corresponding diminishment in the force urgency thereof until there is an overbalance of spring urgency causing ascending movement in said switch arm again re-closing said clamp.

2. An intravenous system flow control as claimed in claim 1 wherein the pitch of said threaded rotor is calibrated to the volume of said supply volume of fluid, whereby the extent of rotation of said rotor which occurs in response to the cyclical operation of said timer correspondingly determines the volume of fluid flow occurring during each cycle of operation.