US 6,981,960 B2
Closed-loop IV fluid flow control
Steve T. Cho, Santa Clara, Calif. (US); and Gene E. Clark, Redwood, Calif. (US)
Assigned to Hospira, Inc., Lake Forest, Ill. (US)
Filed on Dec. 04, 2003, as Appl. No. 10/727,702.
Application 10/727702 is a continuation of application No. 09/628846, filed on Jul. 31, 2000, granted, now 6,685,668.
Prior Publication US 2004/0087895 A1, May 06, 2004
Int. Cl. A61M 31/00 (2006.01)
U.S. Cl. 604—65 4 Claims
OG exemplary drawing
 
1. A flow sensor device for monitoring a fluid flow through a fluid line to a patient, comprising:
a flow sensor adapted to be disposed in a fluid path of a medicinal fluid flowing through a fluid line, said flow sensor producing a signal indicative of a rate of flow of a medicinal fluid through the fluid path, said flow sensor includes an orifice disposed in the fluid path, said orifice having a cross-sectional size that is substantially less than that of the fluid path, both proximal and distal to the orifice, and a pressure-sensing module configured to sense a pressure drop across the orifice, said pressure-sensing module producing the signal in response thereto;
wherein the pressure sensing module further comprises a distal pressure sensor and a proximal pressure sensor, said distal pressure sensor monitoring a distal pressure of the medicinal fluid, downstream of the orifice, and said proximal pressure sensor monitoring a proximal pressure of the medicinal fluid, upstream of the orifice, a difference between the distal pressure and the proximal pressure determining the signal supplied to a processor, which is indicative of the rate of flow of medicinal fluid through the fluid line.