Patent DE3828478A1 successfully refreshed from Google Patents.
US3800794A
Expired / Lapsed
US
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Method and apparatus for fluid flow control
Assignee: Ivac Medical Systems Inc
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Filing: 1970-12-30
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Granted: 1974-04-02
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Expires: 1990-12-30
Abstract
Abstract A method and apparatus for parenteral administration of medical fluids, wherein a normally shut-off intravenous feeding tube is selectively opened at a frequency and open period duration automatically regulated by a digital control system to establish a fluid flow rate at any selected rate over a wide dynamic range. Measured and desired flow rates are converted to digital electrical signals and compared, the electrical difference being used to vary a control voltage which establishes the width of energizing pulses controlling a member for opening the feeding tube. The frequency of the energizing pulses is a high, preferably non-integral, multiple of the desired drop flow rate. Appropriate alarms respond to out-of-limit conditions indicated by the magnitude of the control voltage.
Inventors
- 👤 H Georgi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:45
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635; A; A61; A61M; A61M5/00; A61M5/14; A61M5/168; A61M5/16886; A61M5/1689; Y; Y10; Y10S; Y10S128/00; Y10S128/13; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7761
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
131 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and fluid conduit means coupled to said drop forming means, a method of controlling the rate of drop flow through said fluid conduit means, comprising the steps of: clamping said fluid conduit to a substantially shut-off state; producing control pulses having a frequency higher than a desired drop flow rate through said fluid conduit: and repetitively opening and closing said fluid conduit to flow in response to said control pulses, the frequency of opening said fluid conduit being at a higher frequency than the desired drop flow rate through said fluid conduit, whereby a plurality of control pulses and cycles of opening and closing said fluid conduit are required to produce each individual drop of flow.
Claim 2
Dependent Claim
131 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and fluid conduit means coupled to said drop forming means, a method of controlling the rate of drop flow through said fluid conduit means, comprising the steps of: clamping said fluid conduit to a substantially shut-off state; producing control pulses having a frequency higher than a desired drop flow rate through said fluid conduit: and repetitively opening and closing said fluid conduit to flow in response to said control pulses, the frequency of opening said fluid conduit being at a higher frequency than the desired drop flow rate through said fluid conduit, whereby a plurality of control pulses and cycles of opening and closing said fluid conduit are required to produce each individual drop of flow.
Claim 3
Dependent Claim
29 words
A method as set forth in claim 1 wherein said control pulses are produced at a frequency that is a relatively high multiple of the desired drop flow rate.
Claim 4
Dependent Claim
23 words
A method as set forth in claim 1, further including varying the duration of said control pulses to regulate said drop flow rate.
Claim 5
Dependent Claim
28 words
A method as set forth in claim 1, wherein said control pulses are produced at a frequency that is an integral multiple of the desired drop flow rate.
Claim 6
Dependent Claim
28 words
A method as set forth in claim 1, wherein said control pulses are produced at a frequency that is a non-integral multiple of the desired drop flow rate.
Claim 7
Dependent Claim
72 words
A method as set forth in claim 1, further including the steps of: generating a first signal proportional to the actual drop flow rate; generating a second signal proportional to the desired flow rate; comparing said first signal with said second signal to produce a control voltage proportional to the difference between the actual and desired flow rates; and varying the duration of said control pulses in accordance with said control voltage.
Claim 8
Dependent Claim
24 words
A method as set forth in claim 6, wherein said control voltage is the integral of the difference between said first and second signals.
Claim 9
Dependent Claim
25 words
A method as set forth in claim 6, wherein tHe frequency of opening said tube is an integral multiple of the desired drop flow rate.
Claim 10
Dependent Claim
25 words
A method as set forth in claim 6, wherein the frequency of opening said tube is a non-integral multiple of the desired drop flow rate.
Claim 11
Dependent Claim
128 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and a flexible tube coupled to said drop forming means for carrying drop flow, a method of controlling the rate of drop flow through a flexible tube, comprising the steps of: clamping said tube to a substantially shut-off state; producing control pulses at a selected frequency greater than the desired rate of drop flow; monitoring the actual drop flow occurring through said tube; selectively varying the duration of each of said control pulses in accordance with the actual drop flow; and repetitively opening and closing said tube to fluid flow in response to said control pulses to regulate the actual drop flow rate so that it conforms to said desired drop flow rate.
Claim 12
Dependent Claim
128 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and a flexible tube coupled to said drop forming means for carrying drop flow, a method of controlling the rate of drop flow through a flexible tube, comprising the steps of: clamping said tube to a substantially shut-off state; producing control pulses at a selected frequency greater than the desired rate of drop flow; monitoring the actual drop flow occurring through said tube; selectively varying the duration of each of said control pulses in accordance with the actual drop flow; and repetitively opening and closing said tube to fluid flow in response to said control pulses to regulate the actual drop flow rate so that it conforms to said desired drop flow rate.
Claim 13
Dependent Claim
26 words
A method as set forth in claim 10, wherein the frequency of opening said tube is a relatively high multiple of the desired drop flow rate.
Claim 14
Dependent Claim
21 words
A method as set forth in claim 11, wherein said multiple is approximately 10 1/2 times the desired drop flow rate.
Claim 15
Dependent Claim
64 words
A method as set forth in claim 10, further including the steps of: generating a first signal proportional to said monitored actual drop flow; generating a second signal proportional to said desired flow rate; producing a control voltage proportional to the difference between said first signal and said second signal; and varying the duration of said control pulses in accordance with said control voltage.
Claim 16
Dependent Claim
106 words
In a system for parenteral administration of liquids by drop flow, apparatus for controlling the rate of drop flow comprising: drop forming means; a feeding tube coupled to said drop forming means; tube clamping means for closing said feeding tube to prevent liquid flow therethrough; flow rate setting means for designating a desired flow rate; and means responsive to said rate setting means for unclamping said tube at a selected frequency higher than the desired drop flow rate to allow repetative liquid flow through said feeding tube, whereby a plurality of successive cycles of unclamping said tube are required to produce each individual drop of flow.
Claim 17
Dependent Claim
106 words
In a system for parenteral administration of liquids by drop flow, apparatus for controlling the rate of drop flow comprising: drop forming means; a feeding tube coupled to said drop forming means; tube clamping means for closing said feeding tube to prevent liquid flow therethrough; flow rate setting means for designating a desired flow rate; and means responsive to said rate setting means for unclamping said tube at a selected frequency higher than the desired drop flow rate to allow repetative liquid flow through said feeding tube, whereby a plurality of successive cycles of unclamping said tube are required to produce each individual drop of flow.
Claim 18
Dependent Claim
30 words
Apparatus as set forth in claim 14, wherein said means for unclamping said tube operates at a frequency that is a relatively high multiple of the desired drop flow rate.
Claim 19
Dependent Claim
20 words
Apparatus as set forth in claim 15, wherein said frequency is an integral multiple of the desired drop flow rate.
Claim 20
Dependent Claim
20 words
Apparatus as set forth in claim 15, wherein said frequency is a non-integral multiple of the desired drop flow rate.
Claim 21
Dependent Claim
55 words
Apparatus as set forth in claim 14, wherein said means for unclamping said tube at a selected frequency comprises: drive means for said tube clamping means; means for producing a control pulse having said selected frequency; and means for applying said control pulse to said drive means for unclamping said tube at said selected frequency.
Claim 22
Dependent Claim
34 words
Apparatus as set forth in claim 18, wherein said means for producing a control pulse includes: variable frequency pulse generator means for generating a first electrical signal proportional to the desired drop flow rate.
Claim 23
Dependent Claim
109 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and fluid conduit means coupled to said drop forming means, a method of controlling the rate of drop flow through said conduit means, comprising the steps of: clamping said fluid conduit to a substantially shut-off state; selecting a desired drop flow rate; and repetitively opening and closing said fluid conduit to flow, the frequency at which said conduit is opened being higher than the desired drop flow rate through said fluid conduit, whereby a pluraLity of successive cycles of opening and closing said fluid conduit is required to produce each individual drop of flow.
Claim 24
Dependent Claim
109 words
In the parenteral administration of medical fluids by an intravenous set including drop forming means and fluid conduit means coupled to said drop forming means, a method of controlling the rate of drop flow through said conduit means, comprising the steps of: clamping said fluid conduit to a substantially shut-off state; selecting a desired drop flow rate; and repetitively opening and closing said fluid conduit to flow, the frequency at which said conduit is opened being higher than the desired drop flow rate through said fluid conduit, whereby a pluraLity of successive cycles of opening and closing said fluid conduit is required to produce each individual drop of flow.
Claim 25
Dependent Claim
29 words
A method as set forth in claim 20, wherein said fluid conduit is automatically and continuously opened and closed to provide a continuing drop flow at the desired rate.
Claim 26
Dependent Claim
22 words
A method as set forth in claim 20, wherein said frequency is a relatively high multiple of the desired drop flow rate.
Claim 27
Dependent Claim
21 words
A method as set forth in claim 20, wherein said frequency is an integral multiple of the desired drop flow rate.
Claim 28
Dependent Claim
21 words
A method as set forth in claim 20, wherein said frequency is a non-integral multiple of the desired drop flow rate.
Claim 29
Dependent Claim
120 words
In a system for parenteral administration of liquids by drop flow through a feeding tube, apparatus comprising: clamping means for clamping said feeding tube in a normally shut-off state; electrical pulsing means for generating pulses at a rate greater than the desired drop flow rate to periodically energize said clamping means and thereby open said tube to liquid flow; rate setting means for generating an electrical signal proportional to desired drop flow rate; flow monitoring means for monitoring actual drop flow through said tube and generating an electrical signal proportional to measured drop flow rate; and means responsive to both said rate setting means and said flow monitoring means for regulating the pulse length of pulses from said pulsing means.
Claim 30
Dependent Claim
120 words
In a system for parenteral administration of liquids by drop flow through a feeding tube, apparatus comprising: clamping means for clamping said feeding tube in a normally shut-off state; electrical pulsing means for generating pulses at a rate greater than the desired drop flow rate to periodically energize said clamping means and thereby open said tube to liquid flow; rate setting means for generating an electrical signal proportional to desired drop flow rate; flow monitoring means for monitoring actual drop flow through said tube and generating an electrical signal proportional to measured drop flow rate; and means responsive to both said rate setting means and said flow monitoring means for regulating the pulse length of pulses from said pulsing means.
Claim 31
Dependent Claim
56 words
Apparatus as set forth in claim 25, wherein said means responsive to both said rate setting means and said flow monitoring means includes rate memory means for comparing said signals proportional to desired drop flow rate and measured drop flow rate, respectively, and for generating a control signal for establishing the pulse length of said pulses.
Claim 32
Dependent Claim
44 words
Apparatus as set forth in claim 26, wherein said rate memory means integrates the difference between said signals proportional to desired drop flow rate and measured drop flow rate, respectively, and varies said control signal in accordance with the integrated difference between said signals.
Claim 33
Dependent Claim
31 words
Apparatus as set forth in claim 25, wherein said flow monitoring means includes a drop sensing means for generating a pulse train at a frequency proportional to measured drop flow rate.
Claim 34
Dependent Claim
35 words
Apparatus as set forth in claim 25, wherein said rate setting means includes a pulse generator for generating said electrical signal as a pulse train at a higher frequency than the desired drop flow rate.
Claim 35
Dependent Claim
21 words
Apparatus as set forth in claim 29, wherein said frequency is a relatively high multiple of the desired drop flow rate.
Claim 36
Dependent Claim
20 words
Apparatus as set forth in claim 29, wherein said frequency is an integral multiple of the desired drop flow rate.
Claim 37
Dependent Claim
20 words
Apparatus as set forth in claim 29, wherein said frequency is a non-integral multiple of the desired drop flow rate.
Claim 38
Dependent Claim
16 words
Apparatus as set forth in claim 32, wherein said non-integral multiple is approximately 10 1/2 .
Claim 39
Dependent Claim
125 words
In a system for a parenteral administration of liquids by drop flow through a feeding tube, apparatus for controlling the rate of drop flow comprising: tube clamping means normally maintaining said feeding tube in a substantially shut-off state; driver means for selectively energizing said clamping means to unclamp said tube; rate setting means for generating an electrical signal having a frequency greater than the desired drop flow rate; flow monitoring means for monitoring actual drop flow through said feeding tube; and control means responsive to both said rate setting means and said flow monitoring means producing a train of control pulses at the frequency of said electrical signal for regulating the duration of each period of energization of said clamping means by said driver means.
Claim 40
Dependent Claim
125 words
In a system for a parenteral administration of liquids by drop flow through a feeding tube, apparatus for controlling the rate of drop flow comprising: tube clamping means normally maintaining said feeding tube in a substantially shut-off state; driver means for selectively energizing said clamping means to unclamp said tube; rate setting means for generating an electrical signal having a frequency greater than the desired drop flow rate; flow monitoring means for monitoring actual drop flow through said feeding tube; and control means responsive to both said rate setting means and said flow monitoring means producing a train of control pulses at the frequency of said electrical signal for regulating the duration of each period of energization of said clamping means by said driver means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |