Float valve maintains constant level of solution, providing constant drop rate as long as solution can flow into patient's vein. Second float valve allows solution to enter vein, but prevents entry of air

Dimeff, J.

English

NASA Technical Reports Server

May 1975	 B75-10083 
NASA TECH BRIEF 
Ames Research Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Regulator for Intravenous Feeding 
. 
.
The problem: 
To maintain a constant rate of flow of intravenous 
feeding solution from a reservoir and to prevent in-
troduction of air into the vein of a patient when the 
reservoir is empty. 
The solution: 
A constant level of solution (maintained by a float 
valve) provides a constant drop rate as long as solu-
tion can flow into the patient's vein; a second float 
valve allows solution to enter the vein, but prevents 
entry of air. 
How it's done: 
The top of the regulator is equipped with a sharp 
tip so that the rubber stopper of a bottle containing 
sterile feeding solution can be penetrated easily; as 
shown in the diagram, the tip is ported so that only 
filtered air is vented into the bottle. Tubing, attached 
to the bottom port, conducts solution to the patient's 
vein. 
When the bottle containing feeding solution is in-
verted, fluid flows into the upper compartment of the 
regulator, but flow stops after a short time because 
the upper float lifts and presses an 0-ring seal (at the 
top of the float) against the fluid entry port; however, 
as long as the float is supported by solution, the 
metering orifice is open, and solution can flow into 
the drop chamber. Flow of solution past the 0-ring 
seal occurs at the rate established by the aperture 
between the upper pintle and the seat of the metering 
orifice, and the rate is readily adjusted by manipula-
tion of the position of the drop chamber inasmuch 
as its upper section is the seat of the metering orifice. 
Moreover, the valving action provided by the float 
maintains a nearly constant level of solution in the 
upper compartment, thus assuring a nearly constant
drop-rate. The drop chamber is constructed of clear

plastic so that the drop-rate can be monitored visually 
through ports or windows in the body of the device. 
The lower compartment also contains a float-valve 
mechanism; the buoyancy of the float is adjusted so 
Fluid Entry Port
	 A	 Sharp Tip 
Vent Vent 
Filter
	
Jj 7 ,O-Ring Seal 
Upper 
Upper Float	 Compartment 
Upper Pintle 
Window	
2JI7A Metering Orifice 
Drop Chamber	 i'f	 Window 
Drop Chamber 
Exit Valve...
Lower 
Compartment 
Lower Float 
Lower Pintle
Bottom Port 
that it will unseat the lower pintle when the compart-
ment is nearly completely filled with solution. Similar 
to the action explained above for the float in the upper 
(continued overleaf) 
This document was prepared under the sponsorship of the National
	
Government assumes any liability resulting from the use of the 
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information contained in this document, or warrants that such use 
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will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19750000083 2020-03-19T20:04:00+00:00Z
compartment, when the lower float is in its upper-
most position, solution can flow through the bottom 
port into the patient's vein. However, because solu-
tion ordinarily is metered into the lower compartment 
more slowly than it can flow out, the weight of the 
float in the lower compartment is usually supported 
by the lower pintle. Thus, each time a drop of solu-
tion enters the lower compartment, the lower float 
rises just enough to permit flow through the bottom 
port and then settles back into place to seat the lower 
pintle and prevent air from entering the patient's 
vein. If the patient's vein becomes saturated, the 
lower compartment will become nearly filled with 
solution; the lower float will lift and close the drop-
chamber exit valve so that no more solution can flow 
through the drop chamber. Concomitantly, the upper 
float shuts off flow of solution from the supply bottle.
Note: 
No additional documentation is available. Specific 
questions, however, may be directed to: 
Technology Utilization Officer 
Ames Research Center 
Moffett Field, California 94035 
Reference: B75-10083 
Patent status: 
This is the invention of a NASA employee, and a 
patent application has been filed. Inquiries concern-
ing license for its commercial development may be 
addressed to the inventor: Mr. John Dimeff, Ames 
Research Center, Moffett Field, California 94035. 
Source: John Dimeff
Ames Research Center

(ARC-10758)
[J 
B75-10083	 Category 05


Regulator for intravenous feeding

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