JPH0112834Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a removable device or flow control device for controlling the flow of intravenous fluid from a source of intravenous fluid to a patient. In particular, the present invention is a device for precisely controlling the flow of fluid to a patient during operation of the device under normal circumstances such as a room assigned to the patient, and The present invention relates to a flow control device that allows for precise control of fluid flow rate by manual adjustment during abnormal conditions such as moving a patient to or from a patient. For example, the device allows manual control of fluid flow to the patient when removed from an automatic control system, and automatically controls the flow to normalize when the device is coupled into the control system. The present invention relates to a device which is controlled by the user and restores manual control when the device is removed from the control system.

As the medical sciences have become increasingly complex and fragmented, the equipment and techniques used to care for patients have become increasingly sensitive to ensure that patients receive optimal care. For example, after a patient has undergone surgery and is in a state of recovery,
Often intravenous fluids must be introduced to the patient. The rate of fluid introduction into a patient depends on a number of different factors, including the patient's weight, sex, age, and physical condition. As the patient recovers from the illness, the rate of introduction of intravenous fluid into the patient is preferably adjusted to ensure that the patient receives optimal benefit from this fluid.

BACKGROUND OF THE INVENTION Considerable research has been conducted over a considerable period of time to provide satisfactory flow control devices for controlling the rate at which fluids, such as intravenous fluids, are introduced into a patient. Considerable progress has been made in developing satisfactory flow control devices for certain surgeries. For example, a device for pumping fluid to a patient on a precise volumetric basis is described in US Pat. No. 3,985,133.

Until fairly recently, a number of fundamental problems remained with flow control devices that rely on gravity to provide fluid flow to a patient. For example, until recently, there has been no satisfactory flow control device for introducing fluid into a patient at a precisely scheduled rate based on gravity. Additionally, it can be used for sterile and hygienic purposes on different patients so that contamination resulting from use of the flow control device for one patient does not adversely affect the health or safety of subsequent patients. Flow control devices have not existed until recently.

Flow control devices for solving the above-mentioned difficult problems are disclosed, for example, in US Pat. No. 913,294 (June 1978)
(filed on May 7th). The specification of this patent application provides a method for providing intravenous fluid flow to a patient at a precisely scheduled flow rate based on gravity and for providing intravenous fluid flow to any patient under sterile and hygienic conditions. A flow control device is disclosed.

U.S. patent application filed June 7, 1978
No. 913,282 discloses a cassette for an intravenous injection controller. The cassette described in the specification of this patent application is placed within a flow control device to provide fluid flow to a patient in a controlled manner and the flow control device must be used for another patient. It is adapted to be easily removed from the flow control device so that a sterile cassette can be substituted into the flow control device each time a previously used cassette is lost. .

Although the flow control device described in the above-mentioned U.S. patent application provides sterile, gravity-driven fluid flow to a patient at a precisely scheduled rate, the increased range of operation of the flow control device Improvement is still desired. For example, it would be desirable to provide a flow control device that can be coupled to a patient even while the patient is exercising, and that provides a controlled flow of fluid to the patient during such exercise.
In this way, intravenous fluids can be introduced to the patient at such controlled flow rates even during transfer from the operating room to the recovery room or from the recovery room to the patient's personal admission room within the hospital and It would also be desirable to provide a flow control device of this type that can automatically control the flow of fluid by gravity to a patient at a precisely scheduled flow rate after the patient has been transferred to the room.

The flow control device described in the above-referenced US patent application has the capabilities described above. The flow control device includes a separate manual adjustment device that can be manually adjusted to change the rate at which intravenous fluid flows to the patient. This manual control device is useful for controlling fluid flow while a patient is being transferred from an operating room to a recovery room or from a recovery room to an assigned admission room.

The flow control device can also be easily coupled to a control system that automatically controls flow when the patient is recovering in an assigned hospital room.
At this time, the desired flow rate of fluid can then be set in an automatic control system. This overrides manual adjustment of the flow control device and automatically adjusts the fluid flow rate as set.

In this way, when a patient is moved to an assigned inpatient room, precise flow control can be performed automatically, and this control system operates semi-permanently within the assigned inpatient room. Once the desired fluid flow rate is preset, the control system operates in a servo loop to momentarily adjust the fluid flow rate so that the desired fluid flow rate is precisely maintained.

The flow control device is removably disposed within a control system for controlling fluid flow to a patient. Attachment and detachment of the control system and this flow control device can be quickly and easily performed.

(Problem to be solved by the invention) However, the flow control device in the prior art is
It is not possible to change the flow rate of the fluid extremely smoothly, and when changing the flow rate, the flow rate inevitably changes stepwise, or it is difficult to properly control a small amount of flow. There was a problem with that. The flow control devices of the prior art basically have a structure having a common valve body and a valve seat, and delicate control of flow rate cannot be performed to a satisfactory degree. It was not profitable.

SUMMARY OF THE INVENTION The present invention is an apparatus for controlling the flow of intravenous fluid to a patient, comprising a source of intravenous fluid, an inlet conduit, and an outlet conduit. a cassette partially forming a passageway between an inlet conduit and an outlet conduit; a button disposed within the passageway and having a notch formed therein; and a button disposed on the cassette so as to cover the button. a resilient diaphragm mounted on the cassette and movable over the cassette to permit fluid communication through the notch by pressing the resilient diaphragm against the button; a push rod adapted to provide a variably restricted fluid flow within the passageway to control fluid flow through the cassette; and a fluid passageway connecting the source to an inlet conduit of the cassette; and a fluid passageway connecting the cassette outlet conduit to the patient.

(Function) In the present invention, an elastic diaphragm and a button in which a notch is formed are provided as essential components, and when the flow rate of flowing fluid is small, the elastic diaphragm is sucked into the notch. The tendency is for the fluid to flow only through the narrow gap between the elastic diaphragm and the bottom of the cutout. Therefore, under such conditions, it becomes possible to control the fluid flow very precisely and smoothly even when the flow rate is small.

EXAMPLE The flow control device encompassed by the present invention is adapted for use within the control system disclosed in US patent application Ser. No. 913,294. This flow control device can also be included within a cassette as disclosed in U.S. Patent Application No. 913,282, or used as a separate part within a control system without being included in a cassette. ing.

FIG. 3 shows a flow control device that is an embodiment of the present invention. The flow control device includes a source 10 of intravenous fluid and a fluid passageway 12 extending from the source 10 to a control device 14 that forms part of the present invention. Fluid passage 16
extends from the controller 14 to the patient, indicated at 20.

Control device 14 includes a plug member 22 formed from a suitable material, such as plastic material, which constitutes a cassette. Plug member 22
has an inlet conduit 24 configured to receive fluid passageway 12 and an outlet conduit 26 configured to receive fluid passageway 16 . A passageway 28 is disposed between and in communication with the inlet conduit 24 and the outlet conduit 26. A button 30 is disposed within the passageway 28 in a closed loop around one of the conduits, such as the outlet conduit 26. This button 30 preferably has an annular shape. The button 30 is provided with a notch 31 (see FIG. 4) to facilitate controlled fluid flow. The cutout 31 may be V-shaped to progressively control the fluid flow rate.

A resilient diaphragm 32 is disposed within passageway 28. The end of the resilient diaphragm 32 has a bulbous configuration and the bulbous end is disposed within a receptacle 34 provided in the plug member 22 to maintain the resilient diaphragm 32 in taut mutual relation. ing. Resilient diaphragm 32 is positioned to extend in the same direction as the distance between inlet conduit 24 and outlet conduit 26 at the location where inlet conduit 24 and outlet conduit 26 communicate with passageway 28 .

A push rod 36 is disposed within a receptacle 38 provided within plug member 22. A push rod 36 is disposed against the upper surface of the resilient diaphragm within the passageway 28 so as to stretch the resilient diaphragm 32. A tab 40 extends from the plug member 22 and is female threaded for thread engagement on a male threaded projection 42. The knob 40 presses against the push rod 36. The knob 40 may have a frusto-conical outer surface and the outer surface may be knurled or otherwise modified to facilitate gripping.

The knob 40 can be rotatably adjusted on the projection 42 to adjust the pressure applied to the push rod 36. By doing this, push rod 3
6 adjusts the force applied to the elastic diaphragm 32. In this way, button 30
The location of the resilient diaphragm 32 adjacent the passageway 28 allows fluid to flow from the inlet conduit 24 to the outlet conduit 26.
The positioning of the knob 40 can be adjusted to control the flow rate. Manual adjustment of knob 40 thus controls the rate at which fluid flows from source 10 to patient 20.

A cutout 31 is provided in the button 30 to obtain fluid flow to the patient at a low flow rate. This cutout 31 is shown schematically in FIG. At such low liquid levels, the elastic diaphragm 32 has a tendency to be sucked into the notch 31. The positioning of the elastic diaphragm 32 within the cutout 31 depends on the adjustment of the knob 40. As a result,
For a low setting of the knob 40, fluid can only flow through the passage 28 to the outlet conduit 26 in the gap between the elastic diaphragm 32 and the bottom of the V-shaped cutout 31.

The flow control device disclosed above is adapted for use when a patient is being transferred from an operating room to a recovery room or from a recovery room to an assigned inpatient room. The control device 14 is relatively small and thus can even be held in the palm of the hand and thus can be held by a nurse. It can even be placed in the patient's palm as the patient is being transferred from one room to another. During such movement, the flow of fluid to the patient is controlled by adjustment of knob 40 on projection 42.

FIG. 1 illustrates a control system for automatically controlling the flow of fluid to a patient due to gravity.
This control system includes a control device 14 illustrated in FIGS. 2 and 3. The control device 14 is supported in a fixed position relative to the control system by a housing generally designated 50 in FIG. A drive member 52 (FIG. 5) is provided with a socket 54 in the housing 50.
It is included. The receptacle 54 is knurled or otherwise modified in a manner similar to the outer surface of the knob 40 so as to engage the knob 40 and rotate the knob 40 when rotated.
The drive member 52 includes this drive member 52 and the knob 4.
It may be spring loaded to facilitate the driving relationship between the two. The drive member 52 is driven by a stepper motor 56.

Stepper motor 56 is included within a control system illustrated schematically in FIG. This control system includes a flow rate setter 58 (see also FIG. 5). Flow rate setter 58 is preferably located on the front panel of housing 50 and has digital setting capability, preferably consisting of a plurality of progressive numbers. For example, three numbers are provided for setting the ones, tens, and hundreds values to provide the ability to select a digitally represented flow rate between the numbers 1 and 999. Good too.

The signal from the flow rate setting device 58 is sent to the drip sensor 62.
is introduced into a comparator 60 (FIG. 1) for comparison with the actual value of flow sensed by. Drip sensor 62 may be of conventional construction and is operative to sense the number of drops flowing through fluid passageway 12 during a particular period of time, such as one second.
Comparator 60 compares the signals from flow setter 58 and drip sensor 62 to generate an error signal. This error signal is introduced into the stepper motor 56 and operates the stepper motor 56 so that the error signal becomes zero. stepper motor 5
6 drives a drive member 52 which rotates the knob 40 to control the flow of fluid through the outlet conduit 26. In this manner, stepper motor 56 instantaneously controls fluid flow through fluid passageway 16 at the value set by flow setter 58.

As can be seen in FIG. 5, control device 14 is adapted to be removably disposed within housing 50. The housing 50 may be configured to surround only the drive member 52 and stepper motor 56. In this manner, controller 14 attempts to ensure that the control system illustrated in FIG. If so, it can be easily connected into the housing 50.

Controller 14 is also shown generally at 70 in FIG.
and may be contained within a cassette as disclosed in U.S. Patent Application No. 913,282. If control device 14 is included within cassette 70, control device 14 may be permanently disposed within cassette 70 rather than being removable in the embodiments described above. However, even if the control device 14 is included within the cassette 70, the control device 14
The flexibility of being manually adjustable to control the flow of intravenous fluid to the patient or controllable by a control system according to adjustment with a flow setting device 58 as illustrated in FIG. (i.e., free changeability).

If control device 14 is included within cassette 70, control device 14 may be located at any suitable location within the hydraulic circuit provided by cassette 70.
This hydraulic circuit is schematically illustrated in FIG. For example, the control device 14 may be located within the fluid passageway 72 within the cassette 70 at a location 71 indicated by the numeral X. Location 71 communicates with a fluid passageway 72 at a location in front of the fluid branch point in the auxiliary conduit within the cassette 70. In this manner, all fluid flowing through this cassette 70 passes through the controller 14.

The hydraulic circuit illustrated in FIG. 6 includes a pair of auxiliary conduits 74 and 76 extending from fluid passageway 72 to opposite ends of the chamber, designated generally at 78. Valves 80 and 82 are located within auxiliary conduits 74 and 76, respectively.
A resilient diaphragm 84 is disposed in chamber 78 to
8 is divided into a pair of sections 86 and 88.
Auxiliary conduits 90 and 92 extend from compartments 86 and 88, respectively, to fluid passageway 94. Valves 96 and 98 are located in auxiliary conduits 90 and 92, respectively.

The resilient diaphragm 84 can be stretched within the chamber 78 to increase the volume of one compartment and correspondingly decrease the volume of the other compartment. Code 1 for the whole
The transducer designated 00 is an elastic diaphragm 8
4 movements to set the position of the elastic diaphragm 84 at each instant. Transducer 100 generates signals at each instant that control the direction of fluid flow into and out of the chamber. For example, initially valves 80 and 98 are opened and valves 82 and 96 are initially closed. This interaction causes fluid to flow into and out of compartment 86 and out of compartment 88, thus causing elastic diaphragm 84 to flare into compartment 88. When the elastic diaphragm is stretched to a certain limit, transducer 100 closes valves 80 and 98 and closes valve 82.
and generates a signal to open 96. In this interaction, fluid flows into and out of compartment 88 , thus causing transducer 100 to extend into compartment 86 .

In this manner, fluid alternately flows into and out of compartment 86 and out of compartment 88 and into and out of compartment 86. Sections 86 and 8
The flow rate of fluid into and out of the controller 8 is determined by the setting of a knob 40 in the controller 14. The setting of the knob 40 can be adjusted manually or the knob 40 can be adjusted automatically by the control system of FIGS. You can also do that.

(Effects of the invention) As explained above, according to the invention, the flow rate of intravenous fluid to the patient can be controlled extremely precisely by the cooperation between the elastic diaphragm and the button in which the notch is formed. can be controlled. especially,
At low fluid flow rates, the elastic diaphragm has a tendency to be sucked into the notch and the fluid will only flow through the narrow gap between the elastic diaphragm and the bottom of the notch. When the flow rate is small, the flow rate can be controlled extremely precisely and smoothly.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a portion of a control system for controlling the flow of intravenous fluid to a patient by gravity; FIG. 2 is a control system that may be included within the control system of FIG. 1; 3 is a cross-sectional view of the device shown in FIG. 2 when it is removed from the control system shown in FIG. 1 and in a position to provide fluid flow at a very low flow rate. 2 is a sectional view of the control device shown in FIG. 2, FIG. 4 is an enlarged fragmentary sectional view of some elements of the control device shown in FIGS. 2 and 3, and FIG. A perspective view showing the assembled arrangement of the control system shown in FIGS. 2 and 3 and the control device shown in FIGS. 1 is a schematic diagram of a cassette that can be configured to contain a device; FIG. 10... Supply source, 12... Fluid passage, 14...
Control device, 16...Fluid passage, 22...Plug member, 24...Inlet conduit, 26...Outlet conduit, 28
...Aisle, 30...Button, 31...Notch, 3
2...Elastic diaphragm, 34...Socket, 36
... Push rod, 40 ... Knob, 52 ... Drive member, 56 ... Stepper motor, 58 ... Flow rate setting device, 60 ... Comparator, 62 ... Drip sensor, 70 ... Cassette, 72 ... Fluid aisle, 7
4,76...Auxiliary conduit, 78...Room, 80,82
... Valve, 84 ... Elastic diaphragm, 86, 88
...Division, 90, 92...Auxiliary conduit, 94...Liquid passage, 100...Transducer.

Claims (1)

[Scope of utility model registration request] A device for controlling the flow of intravenous fluid to a patient, the device comprising: a source of intravenous fluid;
a cassette having an inlet conduit and an outlet conduit defining a partial passageway between the inlet conduit and the outlet conduit; a button disposed within the passageway and having a notch formed therein; a resilient diaphragm disposed on the cassette to cover the button and permit fluid communication through the passageway; a push rod adapted to apply pressure to provide a variably restricted fluid flow through the notch and into the passageway to control fluid flow through the cassette; A device for controlling fluid flow comprising a fluid passageway connecting an inlet conduit and a fluid passageway connecting an outlet conduit of the cassette to a patient.