Fluid injection system

Abstract

An injection system that eliminates the need for multiple syringe changes common to an angiographic or other catheterization procedure, is disclosed. The subject system includes a pair of reservoirs for respectively maintaining saline solution and contrast dye under pressure for controlled injection into a patient. The reservoirs are maintained full by automatically filled, after a predetermined time delay, whenever any amount is used. Peristaltic pumps connected to supplies of saline solution and contrast dye function to fill and refill the reservoirs.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to medical equipment useful in performing an angiographic or other catheterization procedure. More specifically, the present invention concerns a fluid injection system that is designed for use in carrying out an angiographic procedure or other catheterization.

2. Description of the Prior Art

Recent advances in medical science have included the development and refinement of diagnostic X-ray techniques. Angiography or arteriography is one of such diagnostic X-ray techniques.

Generally, angiography involves the injection of radio-opaque dye or contrast dye into an artery or arteries of a human body under examination. When X-rays are thereafter taken, a shadow is produced by the dye on the X-ray pictures and thereby provides an outline of the arteries in which the dye has been injected. The shadow is due to the X-rays passing through the normal body tissues but not the dye.

Angiography thus allows physicians and other medical diagnosticians to study almost any part of the body as well as the blood vessels and specific organs in a human body. As an example, injection of radio-opaque dye into blood vessels will indicate the presence of obstructions, blockages, or constriction of the arteries. Also identifiable would be displacement of the arteries. Such information is essential in completely studying patients to determine the presence or absence of brain tumors, blood clots, and other abnormalities, and the need for corrective surgery or the like. As a further example, angiography is useful for examining patients that may be suffering from heart disease to determine the existence of blocked or partially obstructed coronary arteries as may be present in connection with an angina condition or following a heart attack.

Contrast dye can also be injected directly into the heart to determine the existence of leaky valves. The basic angiographic procedure is also adapted for use in obtaining pressure measurements as is useful in diagnosing leaky heart valves.

Typically, an angiographic procedure involves directly inserting a catheter into one of the blood vessels of the body. The major artery in the groin is frequently chosen, although other arteries may also be used. A needle may be first inserted into the artery and a catheter then threaded through the hollow of the needle into the artery. The needle can then be removed. Once inserted into the artery, the catheter is then slowly threaded through the artery to have the tip thereof become situated in the area of the body or within the organ to be examined.

It is necessary that the location of the catheter be known at all times. To this end, small amounts of contrast dye are introduced at frequent intervals through the catheter to have the dye fill the blood vessel at the tip of the catheter. A fluoroscope may then be used to provide a specific indication of the whereabouts of the tip of the catheter within the body as it is threaded into the body through the artery.

Dye and saline cannot be left in the catheter for too long a period of time because of the possibility of clot formation. Accordingly, the catheter must be intermittently rinsed with fresh saline solution which is injected through the catheter into the body to wash the dye out of the catheter.

Injection of the dye and saline solutions is presently accomplished by the use of syringes which are alternately manually connected and disconnected from the end of the catheter or extensions thereof. Hence, each injection of contrast dye requires that two separate syringes be successively attached and detached from the catheter. In the course of a single angiographic procedure to study parts of a patien's head or neck, as many as 50 or more syringe changes may be required.

The withdrawal of blood through the catheter, as may be required during an angiographic procedure, would require further attachment and detachment of a syringe or syringes from the catheter.

Culmination of the angiographic procedure occurs when the catheter is finally worked into the position desired, and a relatively large volume of contrast dye is quickly injected under high pressure into the area to be examined. A plurality of X-ray pictures are then taken in quick succession. As an example, study of the heart normally involves injection of 40 cc of dye at a pressure of 1,000 psi. Examination of the brain would typically involve the injection of 8 cc of contrast dye under a pressure of 40 psi. If the X-ray pictures that are taken are satisfactory, the catheter is either removed or relocated to another region of the body for study.

Other forms of catheterization would include hystosalpingograms, retrograde cysternograms and cardiac catheterizations. In each instance, a catheter is inserted into a blood vessel or other body cavity for the purpose of injecting fluid into the cavity, taking pressure measurements, and/or withdrawing blood or other body fluids.

It is clear that the current techniques for performing an angiographic procedure are crude, time consuming, and dangerous, however useful and/or necessary the results may be. Specifically, the need for numerous syringe connections and disconnections as dye and saline solution is injected is tedious as well as time consuming; but perhaps of most importance is the danger presented by the opportunity for clot formation as a result of exposure to air in the course of the many syringe changes.

Accordingly, it is an intension of the subject invention to provide a fluid injection system that completely eliminates any exposure to air in the course of an angiographic procedure and is highly sanitary, which eliminates the need for the multiple syringe connections and disconnections to the catheter, and which permits a physician or other person to safely and quickly perform angiographic procedures.

SUMMARY OF THE INVENTION

Briefly described, the present invention involves a fluid injection system for use in the performance of an angiographic or other catheterization procedure.

More specifically, the subject invention involves a closed fluid system that eliminates the need for the numerous syringe changes that are presently required in the course of an angiographic procedure and which thereby eliminates exposure to air and the attendant dangers resulting from the formation of clots. The system includes a pair of independent, pressurized reservoirs which are respectively continuously filled, after a nominal time delay, with contrast dye and saline solution whenever fluid is drawn from a reservoir. Pumping mechanisms connected to supplies of such fluids are automatically actuated to refill the respective reservoirs. Means are included for providing an indication of both total consumption of the fluids as well as the size of each dose that is injected. A vacuum pump is used to maintain a waste container at a negative pressure with respect to body pressure to enable the extraction of fluid from a patient's body.

The objects and many attendant advantages of the invention will be more readily appreciated as the same becomes better understood by reference to the following description which is to be considered in connection with the accompanying drawings wherein like reference symbols designate like parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a perspective view of the subject invention.

FIG. 2 is a schematic diagram illustrating a partially cut away, frontal, plan view of a console used in conjunction with an angiographic injection system in accordance with the subject invention.

FIG. 3 is a schematic diagram illustrating a partially cut away, side, plan view of the console shown in FIG. 2.

FIG. 4 is a schematic diagram illustrating an electrical circuit that is useful in understanding the operation of the subject invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 of the drawings, an angiographic injection system in accordance with the present invention includes a console unit 2 connected to a supply of contrast dye 4 via tubing 6 and a supply of saline solution 8 via tubing 10. The console 2 is connected to continuously make available and provide the contrast dye and the saline solution to a catheter 12 upon demand via a manually operable valve control 14 and a pair of output tubes 16 and 18, respectively. The console unit 2 is also connected via a vacuum hose 20 to depressurize or reduce the pressure of a waste container 22.

It is to be understood that although contrast dye is discussed herein that any radio-opaque medium suitable for use in an angiographic procedure can be used with the subject invention.

As earlier explained, an angiographic or other catheterization procedure requires the catheter 12 to be threaded into a patient's body via an appropriate artery or other blood vessel. Contrast dye and saline solution is injected through the catheter 12 at frequent intervals to continuously locate and observe the position of the tip thereof. Hence, the manually operated valve control 14 includes a pair of valve actuators 24 and 26, each of which functions to open and close a valve to control the flow of dye and saline solution to the catheter 12 via the console 2. As an example, the valve actuators 24 and 26 may simply be levers which control a three port fluid valve which is effectively opened or closed by turning of the valve actuators 24 and 26 to permit or stop the flow of fluid to or from the catheter 12. Accordingly, each of the actuators 24 and 26 may have a forward position for permitting the injection of fluid through the catheter 12, and a backward position for extracting a fluid through the catheter 12, and a middle position in which no flow is permitted. Any of the numerous types of conventional fluid valves that are available in the prior art may be employed as the valve control 14 and the valve actuators 24 and 26 thereof. Extracted fluid may be directed through a hose 27 to the waste container 22.

Referring to FIGS. 2 and 3, the console 2 includes a pair of identical independent pressurized reservoir systems respectively for the contrast dye provided from the supply 4 and for the saline solution provided from the supply 8. A first reservoir 28 may be used for the contrast dye and a second reservoir 30 may be used for saline solution by being respectively connected to have fluid supplied thereto from the supplies 4 and 8 by a pair of peristaltic pumps 32 and 34 through the tubes 6 and 10. Fluid in the reservoirs 28 and 30 are maintained under pressure by a pair of spring assemblies 36 and 38, respectively.

Considered in greater detail, the reservoirs 28 and 30 may each essentially take the form of a syringe and accordingly include a cylindrical housing 40, an inlet-outlet needle 42, and a plunger 44. The capacity of each of the reservoirs may be in the neighborhood of 20-40 cc; but any other appropriate capacity may be used. As is well known, retraction of the plunger 44 from within the housing 40 will cause fluid to be drawn into the interior cavity of the housing 40. Similarly, forcing fluid into the housing 40 through the needle 42 will cause ejection of the plunger 44. Conversely, insertion of the plunger 44 into the cavity of the housing 40 will force fluid contained therein to be ejected through the needle 42.

An appropriate walled mount 45 may be used to removably support and retain syringes that are emplaced as reservoirs 28 and 30. As shown, the mount 45 may simply involve a clip-like fixture that receives the housing 40 therein and thereby holds the housing 40 stationary. The mounting fixture 45 may, of course, have any other configuration that would allow insertion and removal of the syringes that are emplaced as reservoirs in accordance with the subject invention.

It is to be understood that although a syringe is described for use as reservoirs 28 and 30, other configurations or similar devices may be also employed.

Referring to the saline reservoir 30, as an example, fluid is forced into the reservoir 30 by operation of a peristaltic pump 34 which serves to draw saline solution from the supply 8 via the tubing 10. As shown, the tubing 10 is wound through the pump 34 and is connected to the reservoir 30 via a suitable fluid T-joint 46. The output tubing 18 is also connected to an arm of the T-joint 46. Operation of the pump 34 will cause saline solution to be pumped through the T-joint 46 into the reservoir 30 provided that the output tubing 18 is closed off such as the valve actuator 26. In the event that the output tubing 18 is opened such as by operation of the valve actuator 26, the pump 34 will function to pump fluid through the output tubing 18 and through the catheter 12 assuming that a stop-cock 48, which may be provided, as shown in FIG. 1, is opened rather than closed.

The spring assembly 38 operates to maintain fluid contained by the reservoir 30 under pressure by having a telescopic section 50 thereof positioned against the end of the plunger 44 to urge said plunger 44 into the housing 40 to thereby eject the fluid therein. The amount of force or pressure applied to the plunger 44 by the telescoping section 50 of the spring assembly 38 may be readily adjusted by operation of an adjustment knob 52 which extends through an outer casing 54 of the console 2. The adjustment knob 52 is threadably connected to a spring compression plate 56 which functions to compress a spring 58 as it is driven in a downward position in FIG. 2 in response to appropriate turning of the knob 52. Increased compression of the springs 58 will, of course, increase the force applied to the plunger 44 via the telescoping section 50 and thereby increase the pressure of the fluid contained by the reservoir 30. The spring assembly 38 may be readily calibrated in a manner well known to persons skilled in the art to obtain desired fluid pressures for the contrast dye and saline solution that are provided from the reservoirs 28 and 30 and as may be required for the examination of different organs, i.e., 40 psi for injection of contrast dye into a brain being examined.

The telescoping section 50 may be equipped with an indicator arrow 60 or the like which extends through a slot 62 in the casing 54 to provide a visual indication, in conjunction with a scale 64, of the size of each dose of fluid ejected or injected into a patient. To this end, refilling a reservoir after the ejection of each dose is nominally delayed, i.e., 5 seconds, to permit a true uninterrupted dose indication, as is explained hereinbelow.

The indicator arrow 60 would be in a raised position when the reservoir is filled and would be lowered as the plunger 44 is driven into the housing 40 by the spring assembly 38 as fluid is ejected. The scale 64 may involve any appropriate units such as cubic centimeters (cc) and may be simply painted or etched onto the casing 54. The indicating arrow 60 may also be mechanically connected to trigger an audible indicating device as predetermined amounts of fluid are ejected. For example, a reed comb-type of device could be used to sound a tone as the indicator arrow 60 is lowered past individual reeds.

A window 65 may also be provided to allow visual observation of the contents of each reservoir.

An indication of total consumption of saline solution may be desired and be provided by an indicator 66 which is connected by a drive belt 68 to be driven in conjunction with operation of the peristaltic pump 34. An armature assembly 69 on the pump 34 may be conveniently used for this purpose. Operation of the pump 34 would cause the belt 68 to simultaneously drive the indicator 66 in a conventional fashion. The indicator 66 may be in the form of an odometer-like device or any other conventional indicator device well known in the prior art. A similar indicator would be connected to the pump 32 to indicate total consumption of contrast dye.

As a safety measure, the output tubes 16 and 18 may be connected to be monitored by a bubble detector 70 of a type well known in the art. For example, a bubble indicator 70 may simply involve a photoelectric cell which would be positioned to produce an output signal whenever illumination directed thereon were to vary, such as by being increased in response to the passage of an air bubble 70. The bubble detector 70 would be connected to de-energize the system such as by automatically opening a switch or the like, as is explained hereinafter in greater detail.

A vacuum pump 72 may be contained within the casing 54 and have connected thereto the vacuum hose 20 of which one end is placed in the closed waste container 22 to reduce the pressure therein, Depressurizing the container 22 to a pressure that is lower than body pressure functions to facilitate withdrawal of fluid from a patient's body. A vacuum gauge 73 may be mounted on the casing 54 of the console 2.

Refilling of the reservoirs 28 and 30 after the withdrawal of any fluid therefrom is automatically accomplished by having the pumps 32 and 34 respectively connected to be automatically operated whenever the reservoir is not full. Any convenient switching arrangement can be used such as by having a wiper arm shown in FIG. 3 serve as a portion of an electrical switch that is closed whenever the plunger 44 of the reservoir is at any position other than at a maximum raised position such as is shown for the plunger 44 of the reservoir 30 in FIG. 2. Such electrical switch may simply involve a contact strip (not shown) that contacts the wiper arm 71 when the plunger 44 is lowered. Clearly the wiper arm 71 can be appropriately secured to the indicator arrow 60 or to the telescoping section 50 (as shown) or even to the plunger 44, although such connection would be less desirable.

Clearly, the subject fluid injection system is a closed fluid system and hence substantially eliminates the possibility of air bubbles being introduced into the subject. Further, the subject system is highly sanitary in that all portions of the system that are exposed to or come in contact with the saline solution and contrast dye are disposable and readily replaceable. Specifically, the disposable items would include the supply bottles 4 and 8, tubes 6 and 10, reservoirs 28 and 30, T-joints 46, tubes 16 and 18, and finally valve control 14. The catheter 12 is normally an expensive item and hence is sterilized for reuse.

Referring to FIG. 4, an electrical circuit for each of the peristaltic pumps 32 and 34 may include a plug 74 which is adapted to be connected to any conventional AC power source. Using the pump 34 as an example, the electrical circuit may include a series connected main power switch 76 which may be in the form of a push button switch, or a toggle switch, etc., a safety fuse 76, a refill switch 80, a delay timer 82, and a bubble detector switch 84. The refill switch 80 would be closed in response to the reservoir 30 not being filled as above discussed and would be opened whenever the reservoir 30 is filled.

The delay timer 82 would serve to delay energization of the pump 34 and hence delay the filling of the reservoir 30 to permit the dose indicator 60 to provide an accurate indication before the corresponding pump commences to refill the reservoir. Any conventional time delay device may be used to produce the desired nominal time delay, i.e., four to six seconds, following each withdrawal of fluid before operation of the pumps 32 and 34. The time delay is chosen to accommodate the time needed to complete an injection. The bubble detector switch 84 would normally be closed; but would be automatically opened in response to detection of an air bubble by the detector 70.

It is to be understood that the pumps 32 and 34 may be effectively connected in parallel in a single circuit or in separate circuits similar to that illustrated by FIG. 4.

The vacuum pump 72 may also be connected to have an electrical circuit similar to that shown by FIG. 4 or be connected to a common power buss along with the pumps 32 and 34. However, there would be no need for any time delay as the vacuum pump 72 may be continuously operated.

From the foregoing it is now clear that the subject invention presents a fluid injection system that permits contrast dye and saline solution to be readily supplied to and injected through a catheter without the need for the numerous connections and disconnections that must be manually accomplished in accordance with present techniques and which thereby eliminates or substantially reduces the danger of clot formation resulting from exposure to air, extensive time consumption, and any discomfort that may be attendant to the conventional need for such syringe changes.

While a preferred embodiment of the present invention has been described hereinabove, it is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense and that all modifications, constructions and arrangements which fall within the scope and spirit of the invention may be made.

Claims

What is claimed is:

1. An angio-graphic injection system for continuously providing to a catheter supplies of two separate fluids used in the performance of a catheterization procedure, the injection system comprising:

a pair of reservoir means for containing a ready supply of said two fluids, respectively;

a pair of pressurizing means each connected to one of said pair of reservoir means for maintaining said fluids contained therein under a predetermined pressure;

a pair of pumping means respectively connected to one of said reservoir means for pumping fluid into said reservoir means from a source thereof to continuously maintain said reservoir means in a filled condition;

and fluid conduit means for interconnecting said respective reservoir means and pump means, said fluid conduit means provided with means for being connected to a catheter to supply said fluids thereto.

2. The injection system defined by claim 1, further including a pair of pump actuating means each connected to be respectively responsive to a different one of said reservoir means being in an unfilled condition for causing a pumping means to be energized to pump fluid to said reservoir means until obtaining a filled condition.

3. The injection system defined by claim 2, said pump actuating means including time delay means for delaying energization of said pumping means by a predetermined period of time following said reservoir means having an unfilled condition.

4. The injection system defined by claim 1, further including vacuum means adapted to be connected to a container for receiving waste fluids for reducing the interior pressure of said container.

5. The injection system defined by claim 1, further including valve control means connected to said pair of reservoir means for controlling the withdrawal of said fluids from both said reservoir means.

6. The injection system defined by claim 1, said pair of reservoir means each including:

a housing defining an interior cavity;

a plunger adapted to be inserted into and retracted from said interior cavity; and

inlet means extending through said housing into said cavity whereby said fluid is injected into and ejected from said interior cavity through said inlet means.

7. The injection system defined by claim 1, said pair of reservoir means each including a syringe having an inlet needle thereof connected to have fluid ejected therethrough and pumped therethrough by said pumping means.

8. The injection system defined by claim 1, said pair of pumping means each including a peristaltic pump.

9. The injection system defined by claim 1, said pair of pressurizing means each including spring biased means for applying a mechanical force to said reservoir means corresponding thereto to have fluid contained by said reservoir means maintained at a predetermined pressure in said reservoir.

10. The injection system defined by claim 9, said spring biased means including:

a telescoping member;

a spring positioned to apply a mechanical force to said telescoping member; and means for adjustably compressing said spring

to adjust said mechanical force applied to said telescoping member in accordance with said determined pressure.

11. The injection system defined by claim 2, each of said pump actuating means including:

switching means responsive to a corresponding one of said reservoir means being in an unfilled condition for causing electrical energy to be applied to a corresponding one of said pumping means; and

time delay means connected to said switching means for delaying energization of said pumping means by a predetermined period of time following said reservoir means having an unfilled condition.

12. The injection system defined by claim 6, said pair of pressurizing means each including spring biased means for applying a force to said plunger at a corresponding one of said reservoir means to have fluid contained in said interior cavity maintained at a predetermined pressure.

13. The injection system defined by claim 12, said spring biased means including:

a telescoping member;

a spring positioned to apply a mechanical force to said telescoping member; and

means for adjustably compressing said spring to adjust said mechanical force applied to said telescoping member in accordance with said determined pressure.

14. The injection system defined by claim 13, further including a pair of pump actuating means each connected to be respectively responsive to a different one of said reservoir means being in an unfilled condition for causing a pumping means to be energized to pump fluid to said reservoir means until obtaining a filled condition.

15. The injection system defined by claim 14, each of said pump actuating means including:

switching means responsive to a corresponding one of said reservoir means being in an unfilled condition for causing electrical energy to be applied to a corresponding one of said pumping means; and

time delay means connected to said switching means for delaying energization of said pumping means by a predetermined period of time following said reservoir means having an unfilled condition.

16. The injection system defined by claim 15, further including valve control means connected to said pair of reservoir means for controlling the withdrawal of said fluids from both said reservoir means.

17. The injection system defined by claim 16, further including vacuum means adapted to be connected to a container for receiving waste fluids for reducing the interior pressure of said container.

18. The injection system defined by claim 17, said pair of pumping means each including a peristaltic pump.

19. The injection system defined by claim 6 further including indicator means for providing an indication of the volume of each dose of fluid ejected from said reservoir means, said indicator means being positioned to respond to movement of said plunger of said reservoir means.

20. The injection system defined by claim 6, further including mounting means for removably securing each of said reservoir means whereby said reservoir means are each adapted to be removable and disposable.

21. The injection system defined by claim 18, said two fluids including saline solution and radio-opaque dyes.