CA1049811A - Liquid flow-rate measuring device - Google Patents
Liquid flow-rate measuring deviceInfo
- Publication number
- CA1049811A CA1049811A CA219,286A CA219286A CA1049811A CA 1049811 A CA1049811 A CA 1049811A CA 219286 A CA219286 A CA 219286A CA 1049811 A CA1049811 A CA 1049811A
- Authority
- CA
- Canada
- Prior art keywords
- liquid
- chamber
- flow
- measuring device
- rate measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
- A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
- A61M1/3621—Extra-corporeal blood circuits
- A61M1/3663—Flow rate transducers; Flow integrators
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
- A61M5/168—Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
- A61M5/16886—Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body for measuring fluid flow rate, i.e. flowmeters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/52—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring the height of the fluid level due to the lifting power of the fluid flow
Landscapes
- Health & Medical Sciences (AREA)
- Heart & Thoracic Surgery (AREA)
- Vascular Medicine (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Hematology (AREA)
- Public Health (AREA)
- Anesthesiology (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Veterinary Medicine (AREA)
- Cardiology (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
- External Artificial Organs (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
Abstract
ABSTRACT OF DISCLOSURE
LIQUID FLOW-RATE MEASURING DEVICE
The invention concerns a novel flow-rate measuring device, comprising a cylindrical liquid recei-ver chamber having an inlet at its head for connection to a liquid supply line and having a liquid outlet opening defined by a thin wall at its base, and a cylindrical liquid delivery chamber having an outlet at its base for connection to a liquid take-off line, said liquid delivery chamber enclosing said liquid receiver chamber and being arranged to receive liquid from the liquid receiver chamber, a pressure equalising aperture being provided in the liquid receiver chamber at or towards its head to equalise pressures developed above volumes of liquid in the liquid receiver chamber and liquid delivery chamber.
LIQUID FLOW-RATE MEASURING DEVICE
The invention concerns a novel flow-rate measuring device, comprising a cylindrical liquid recei-ver chamber having an inlet at its head for connection to a liquid supply line and having a liquid outlet opening defined by a thin wall at its base, and a cylindrical liquid delivery chamber having an outlet at its base for connection to a liquid take-off line, said liquid delivery chamber enclosing said liquid receiver chamber and being arranged to receive liquid from the liquid receiver chamber, a pressure equalising aperture being provided in the liquid receiver chamber at or towards its head to equalise pressures developed above volumes of liquid in the liquid receiver chamber and liquid delivery chamber.
Description
LIQUID FLOW-RATE MEASURING DEVICE
This invention relates to a liquid flow-rate measuring device. More particularly, the invention is concerned with a liquid flow-rate measuring device adapted for measuring the flow rate of blood in an extracorporeal blood handling system.
Methods employed for measuring the flow of liquids, particularly blood, involve the use of an electronic flow meter or measurement of the time taken for a gas bubble injection into a blood line to traverse a predetermined distance. Other means for measuring flow rate of liquid comprise measurement by physical means, such as by means of a pendulum located in the liquid flow line. For expense reasons, most liquid flow-rate measuring devi-ces ane not disposable, and it is an object of this invention to ; provide a device of sufficiently low cost to enable disposal after a single use, e.g. in measuring the flow-rate of blood in an extracorporeal blood handling system.
In accordance with the invention, there is provided a liquid flow-rate measuring device comprising a cylindrical liquid ` receiver chamber having an inlet at its head for connection to a liquid supply line and having a liquid outlet opening defined by a thin wall at its base, and a cylindrical liquid delivery chamber having an outlet at its base for connection to a liquid take-off line, said liquid delivery chamber enclosing said liquid receiver chamber and being arranged to receive liquid from the liquid receiver chamber, a pressure equalising aperture being provided in the liquid receiver chamber at or towards its head to equalise pressures developed above volumes of liquid in the liquid receiver chamber and liquid delivery chamber.
The liquid receiver chamber and liquid delivery chamber ~-are most preferably of transparent material enabling visual observation of the level of liquid in the liquid receiver chamber.
Otherwi~e, some other means for determiming the level of liquid ~ -. ,, . ,- , : , ~ . , . , ,, : . , in the liquid receiver chamber would be necessary, such as an electronic blood level monitoring device.
The liquid receiver chamber may be provided with cali-brated liquid level markings which indicate the flow-rate of liquid through the device as a function of the height of liquid in the liquid receiver chamber.
A filter for filtering liquid passing through the device may be provided at the base of the liquid delivery chamber. For use in measuring the flow rate of blood, the filter material and indeed ~11 other parts which come into contact with the blood, must be of a sterile material which is compatible with the blood.
As already indicated, the liquid flow-rate measuring device of the invention may be adapted for measuring blood flow-rate in a blood line of an extracorporeal blood handling system.
Thus the apertures and size of the cylindrical liquid receiver chamber and cylindrical liquid delivery chamber, inlets and out-` lets may be dimen~ioned to measure the flow rate of blood.
At least one access conduit leading into the side of theliquid delivery chamber may be provided, which access conduit may be employed for taking samples of blood by conventional means, such as with the aid of a syringe. Similarly, the access conduit may be employed for measuring the pressure of gas above liquid (blood) in the liquid delivery chamber.
A control valve for controlling liquid flow-rate and hence back-pressure in the device may be provided at the outlet of the liquid delivery chamber. The control valve may be of con- -ventional type.
The invention will now be described with reference to the accompanying drawing showing, by way of example, a liquid flow rate measuring device in accordance with invention.
- The drawing shows a cross section of the liquid flow ~ rate measuring device referréd to generally by reference numeral ' : '; ~ , c;l l o .
The liquid flow-rate measuring device comprises a cyl-. indrical liquid receiver chamber 12 having an inlet 14 at its ,c~ head for connection to a liquid supply line 16. A liquid outlet opening 18 is defined by a thin wall 20 at the base of the liquid receiver chamber 12, said thin wall being formed by the edges defined by moulding or otherwise producing a frustro-conical cut-out 22 in the base wall of the liquid receiver chamber.
A cylindrical liquid delivery chamber 24 having an out- :
let 26 at its base for connection to a liquid take-off line 28 encloses the liquid receiver chamber 12 and is arranged to receive ~
liquid f~om the liquid receiver chamber flowing th~ough its liquid outlet opening 18.
Pressure equalizing apertures 30 are provided in the liquid receiver chamber 12 towards its head to equalize pressures developed above volumes of liquid in the liquid receiver chamber 12 and liquid delivery chamber 24.
, . The liquid receiver chamber 12 and liquid delivery chamber 24 are of transparent material, such as of a suitable plastics material enabling visual observation of the level of liquid in the liquid receiver chamber 12. The liquid receiver chamber is provided with calibrated markings 32 which indicate the flow-rate of liquid through the device as a function of the ~.
height of l~quid in the rece~ver chamber 12. ~-A filter 34 for filtering liquid passing through the device 10 is provided at the base of the liquid delivery chamber 24. The filter 34 is seated over a converging opening 36 in the base wall of the liquid delivery chamber.
Access conduits 38 and 40 leading at an acute angle into . 30 the side of the liquid delivery chamber are provided. The access ~.
conduits may be sealed closed with latex rubber caps, and samples ..
of liquid (blood) may be taken from the liquid delivery chamber ' 1~49811 with the aid of a syringe. The access conduits 38 and 40 may find other applications, such as for monitoring the pressure of gas above liquid (blood~ in the liquid delivery chamber, or for adding saline, heparine and the like to blood in the liquid delivery chamber 24.
A control valve 38 for controlling liquid flow-rate and hence back-pressure in the device 10 is provided at the outlet 26 of the liquid delivery chamber 24, in the liquid take-off line 28.
The liquid flow-rate measuring device of the invention, in use in an extracorporeal blood handling system such as a hemo-dialysis system, may conveniently be situated downstream from a blood pump referred to by reference numeral 42 and downstream from an artificial kidney or blood dialyser referred to by refer-ence numeral 44.
In:.operation, liquid (blood) flows through the liquid supply line 16 and into the liquid receiver chamber 12 through the inlet 14. The level to which liquid builds up in the liquid receiver chamber is dependent on the rate of flow of liquid into the liquid receiver chamber, and the dimension of liquid outlet opening 18. Liquid continuously flows through the liquid outlet opening 18 and partially fills the liquid delivery chamber 24.
The liquid then passes out from the liquid delivery chamber 24 through the outlet 26 after having been filtered through the filter 34.
A stable condition, if flow rate of liquid is substant-ially constant, sets in fairly rapidly, and the flow-rate of liq-uid through the device 10 can be read off directly from the calibrated markings 32 as a function of the height of liquid in the liquid receiver chamber 12.
This invention relates to a liquid flow-rate measuring device. More particularly, the invention is concerned with a liquid flow-rate measuring device adapted for measuring the flow rate of blood in an extracorporeal blood handling system.
Methods employed for measuring the flow of liquids, particularly blood, involve the use of an electronic flow meter or measurement of the time taken for a gas bubble injection into a blood line to traverse a predetermined distance. Other means for measuring flow rate of liquid comprise measurement by physical means, such as by means of a pendulum located in the liquid flow line. For expense reasons, most liquid flow-rate measuring devi-ces ane not disposable, and it is an object of this invention to ; provide a device of sufficiently low cost to enable disposal after a single use, e.g. in measuring the flow-rate of blood in an extracorporeal blood handling system.
In accordance with the invention, there is provided a liquid flow-rate measuring device comprising a cylindrical liquid ` receiver chamber having an inlet at its head for connection to a liquid supply line and having a liquid outlet opening defined by a thin wall at its base, and a cylindrical liquid delivery chamber having an outlet at its base for connection to a liquid take-off line, said liquid delivery chamber enclosing said liquid receiver chamber and being arranged to receive liquid from the liquid receiver chamber, a pressure equalising aperture being provided in the liquid receiver chamber at or towards its head to equalise pressures developed above volumes of liquid in the liquid receiver chamber and liquid delivery chamber.
The liquid receiver chamber and liquid delivery chamber ~-are most preferably of transparent material enabling visual observation of the level of liquid in the liquid receiver chamber.
Otherwi~e, some other means for determiming the level of liquid ~ -. ,, . ,- , : , ~ . , . , ,, : . , in the liquid receiver chamber would be necessary, such as an electronic blood level monitoring device.
The liquid receiver chamber may be provided with cali-brated liquid level markings which indicate the flow-rate of liquid through the device as a function of the height of liquid in the liquid receiver chamber.
A filter for filtering liquid passing through the device may be provided at the base of the liquid delivery chamber. For use in measuring the flow rate of blood, the filter material and indeed ~11 other parts which come into contact with the blood, must be of a sterile material which is compatible with the blood.
As already indicated, the liquid flow-rate measuring device of the invention may be adapted for measuring blood flow-rate in a blood line of an extracorporeal blood handling system.
Thus the apertures and size of the cylindrical liquid receiver chamber and cylindrical liquid delivery chamber, inlets and out-` lets may be dimen~ioned to measure the flow rate of blood.
At least one access conduit leading into the side of theliquid delivery chamber may be provided, which access conduit may be employed for taking samples of blood by conventional means, such as with the aid of a syringe. Similarly, the access conduit may be employed for measuring the pressure of gas above liquid (blood) in the liquid delivery chamber.
A control valve for controlling liquid flow-rate and hence back-pressure in the device may be provided at the outlet of the liquid delivery chamber. The control valve may be of con- -ventional type.
The invention will now be described with reference to the accompanying drawing showing, by way of example, a liquid flow rate measuring device in accordance with invention.
- The drawing shows a cross section of the liquid flow ~ rate measuring device referréd to generally by reference numeral ' : '; ~ , c;l l o .
The liquid flow-rate measuring device comprises a cyl-. indrical liquid receiver chamber 12 having an inlet 14 at its ,c~ head for connection to a liquid supply line 16. A liquid outlet opening 18 is defined by a thin wall 20 at the base of the liquid receiver chamber 12, said thin wall being formed by the edges defined by moulding or otherwise producing a frustro-conical cut-out 22 in the base wall of the liquid receiver chamber.
A cylindrical liquid delivery chamber 24 having an out- :
let 26 at its base for connection to a liquid take-off line 28 encloses the liquid receiver chamber 12 and is arranged to receive ~
liquid f~om the liquid receiver chamber flowing th~ough its liquid outlet opening 18.
Pressure equalizing apertures 30 are provided in the liquid receiver chamber 12 towards its head to equalize pressures developed above volumes of liquid in the liquid receiver chamber 12 and liquid delivery chamber 24.
, . The liquid receiver chamber 12 and liquid delivery chamber 24 are of transparent material, such as of a suitable plastics material enabling visual observation of the level of liquid in the liquid receiver chamber 12. The liquid receiver chamber is provided with calibrated markings 32 which indicate the flow-rate of liquid through the device as a function of the ~.
height of l~quid in the rece~ver chamber 12. ~-A filter 34 for filtering liquid passing through the device 10 is provided at the base of the liquid delivery chamber 24. The filter 34 is seated over a converging opening 36 in the base wall of the liquid delivery chamber.
Access conduits 38 and 40 leading at an acute angle into . 30 the side of the liquid delivery chamber are provided. The access ~.
conduits may be sealed closed with latex rubber caps, and samples ..
of liquid (blood) may be taken from the liquid delivery chamber ' 1~49811 with the aid of a syringe. The access conduits 38 and 40 may find other applications, such as for monitoring the pressure of gas above liquid (blood~ in the liquid delivery chamber, or for adding saline, heparine and the like to blood in the liquid delivery chamber 24.
A control valve 38 for controlling liquid flow-rate and hence back-pressure in the device 10 is provided at the outlet 26 of the liquid delivery chamber 24, in the liquid take-off line 28.
The liquid flow-rate measuring device of the invention, in use in an extracorporeal blood handling system such as a hemo-dialysis system, may conveniently be situated downstream from a blood pump referred to by reference numeral 42 and downstream from an artificial kidney or blood dialyser referred to by refer-ence numeral 44.
In:.operation, liquid (blood) flows through the liquid supply line 16 and into the liquid receiver chamber 12 through the inlet 14. The level to which liquid builds up in the liquid receiver chamber is dependent on the rate of flow of liquid into the liquid receiver chamber, and the dimension of liquid outlet opening 18. Liquid continuously flows through the liquid outlet opening 18 and partially fills the liquid delivery chamber 24.
The liquid then passes out from the liquid delivery chamber 24 through the outlet 26 after having been filtered through the filter 34.
A stable condition, if flow rate of liquid is substant-ially constant, sets in fairly rapidly, and the flow-rate of liq-uid through the device 10 can be read off directly from the calibrated markings 32 as a function of the height of liquid in the liquid receiver chamber 12.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A liquid flow-rate measuring device, comprising a cylindrical liquid receiver chamber having an inlet at its head for connection to a liquid supply line and having a liquid outlet opening defined by a thin wall at its base, and a cylindrical liquid delivery chamber having an outlet at its base for connection to a liquid take-off line, said liquid delivery chamber enclosing said liquid receiver chamber and being arranged to re-ceive liquid from the liquid receiver chamber, a pressure equalizing aperture being provided in the liquid receiver chamber at or towards its head to equalize pressures developed above volumes of liquid in the liquid receiver chamber and liquid delivery chamber.
2. A liquid flow-rate measuring device according to claim 1, in which the liquid receiver chamber and liquid delivery chamber are of transparent material enabling visual observation of the level of liquid in the liquid receiver chamber.
3. A liquid flow-rate measuring device according to claim 2, in which the liquid receiver chamber is provided with calibrated liquid level markings indicating the flow-rate of liquid through the device as a function of the height of liquid in the liquid receiver chamber.
4. A liquid flow-rate measuring device according to any one of claims 1 to 3, in which a filter for filtering liquid passing through the device is provided at the base of the liquid delivery chamber.
5. A liquid flow-rate measuring device according to any one of claims 1 to 3, adapted for measuring blood flow-rate in a blood line of an extracorporeal blood handling system.
6. A liquid flow-rate measuring device according to any one of claims 1 to 3 in which there is provided at least one liquid access conduit leading into the side of the liquid delivery chamber.
7. A liquid flow-rate measuring device according to any one of claims 1 to 3, in which a control valve for control-ling liquid flow rate and hence back-pressure in the device is provided at the outlet of the liquid delivery chamber.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT40007/74A IT1005475B (en) | 1974-02-04 | 1974-02-04 | APPARATUS FOR THE MEASUREMENT OF THE BLOOD FLOW IN THE HEMO DIALYSIS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1049811A true CA1049811A (en) | 1979-03-06 |
Family
ID=11246407
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA219,286A Expired CA1049811A (en) | 1974-02-04 | 1975-02-03 | Liquid flow-rate measuring device |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5812532B2 (en) |
| CA (1) | CA1049811A (en) |
| CH (1) | CH588687A5 (en) |
| DE (1) | DE2504402C2 (en) |
| FR (1) | FR2260084B1 (en) |
| GB (1) | GB1489440A (en) |
| IT (1) | IT1005475B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4136693A (en) * | 1977-05-10 | 1979-01-30 | Johnson & Johnson | Constant flow I.V. device |
| US4661246A (en) * | 1984-10-01 | 1987-04-28 | Ash Medical Systems, Inc. | Dialysis instrument with dialysate side pump for moving body fluids |
| FR2579319A1 (en) * | 1985-03-25 | 1986-09-26 | Lagrandiere Marc De | Method and device for static measurement of a liquid flow rate or of a pressure |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2767581A (en) * | 1952-09-17 | 1956-10-23 | Forrest G Moorehead | Flow meter |
-
1974
- 1974-02-04 IT IT40007/74A patent/IT1005475B/en active
-
1975
- 1975-01-31 GB GB4385/75A patent/GB1489440A/en not_active Expired
- 1975-01-31 FR FR7503178A patent/FR2260084B1/fr not_active Expired
- 1975-02-03 JP JP50013495A patent/JPS5812532B2/en not_active Expired
- 1975-02-03 DE DE2504402A patent/DE2504402C2/en not_active Expired
- 1975-02-03 CA CA219,286A patent/CA1049811A/en not_active Expired
- 1975-02-04 CH CH129275A patent/CH588687A5/xx not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| CH588687A5 (en) | 1977-06-15 |
| JPS5812532B2 (en) | 1983-03-09 |
| GB1489440A (en) | 1977-10-19 |
| FR2260084B1 (en) | 1978-04-21 |
| JPS50115554A (en) | 1975-09-10 |
| IT1005475B (en) | 1976-08-20 |
| FR2260084A1 (en) | 1975-08-29 |
| DE2504402C2 (en) | 1985-06-20 |
| DE2504402A1 (en) | 1975-08-07 |
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