US20020143294A1 - Catheter fluid control system - Google Patents

Abstract

A system and method is provided including a fluid communications network that sends priming and waste fluid to a waste bag, obviating the presence of open fluid containers in an operating room or catheter lab. The fluid communications network is constructed and arranged to allow nearly automated priming and bubble removal, thereby reducing the possibility of operator caused errors in set-up and reducing the time required for set-up. The fluid communications network is useable for attachment to a balloon catheter for inflation thereof. In order to provide greater control and automation of the inflation of the balloon catheter, a conversion kit is provided that can be used to convert an existing automatic injector into an injector useable for automatically controlling the small amount of injection fluid typically associated with balloon catheters.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is related to provisional application serial No. 60/268568, entitled MEDICAL DEVICE WITH AUTO START-UP, filed Feb. 14, 2001, and to provisional application serial No. 60/269112, entitled AUTOMATED BALLOON INFLATION DEVICE USED IN CONJUNCTION WITH AN AUTOMATED VARIABLE DISPENSING RATE INJECTION SYSTEM, filed Feb. 15, 2001, and claims priority from both of these provisional applications.[0001]
BACKGROUND OF THE INVENTION
• The device pertains to a disposable tubing kit that is attachable to a syringe of an automatic injection device. Automatic injection devices, such as applicants' device described in U.S. Pat. No. 6,099,502 and incorporated by reference herein, are used to deliver fluids such as saline and contrast agents through a catheter to a patient. The devices typically include a motor-driven linear actuator that forces a plunger through a syringe, thereby creating a desired fluid flow into the patient. For sanitation purposes, the syringe and all associated tubing between the patient and the syringe are disposable.[0002]
• Preparing the automatic injection device for operation is a time-consuming process. Various tubes must be connected together and to the device. The operator preparing the injection device for operation must be careful to ensure that the connections are tight and that none of the tubes are pinched or otherwise blocked. Furthermore, during the assembly process, the operator will prime various subassemblies with saline and contrast before connecting them to other subassemblies. Priming is done to prevent air from being introduced into the patient. Intermittent priming steps are performed so that fluid-to-fluid connections may be made at predetermined assembly steps. For purposes of this discussion, a fluid-to-fluid connection between two components is made by priming each component so that menisci form at their open ends. The ends are then connected together, thereby merging the menisci and ensuring no air is introduced into the connection.[0003]
• Priming the subassemblies is performed by injecting a desired fluid into the subassembly until the fluid exits the opposite end. The exiting fluid is usually directed into a waste pan, but occasionally spills onto the floor, creating a potential slip hazard, or onto the patient, who is awake during most of the procedures involving the automatic injection device. In addition to creating slip hazards or causing discomfort to the patient, there is growing interest in minimizing the presence of open fluid containers in medical environments. This is especially true for bodily fluids, such as blood, which present a potential biohazard.[0004]
• Once assembled, the components are again primed with fluid to prevent air from being injected into the patient. While priming, the operator taps on the various components in an attempt to dislodge air bubbles from their inner walls. The entire set-up process typically takes 10 to 15 minutes and requires a trained operator. Opportunity for error exists even when the set-up is carefully performed by a trained operator.[0005]
• Some completely assembled, disposable kits are available that include a syringe that is pre-loaded with contrast agent. These kits overcome some of the aforementioned difficulties but present their own challenges to the manufacturer. All medical devices must be delivered sterile and are thus sterilized prior to shipping. Present methods of sterilization include heating using wet or dry autoclaving, gamma irradiation, or EtO sterilization. Each method has drawbacks. Dry autoclaving requires very high temperatures to overcome the lack of heat transfer inherent in dry systems. Wet or steam autoclaving causes dimensional increases in plastic components as the moisture penetrates the plastic and a subsequent decrease as the moisture later escapes. Steam autoclaving further uses a temperature which may cause the polymeric parts to deform. Gamma irradiation requires the use of gamma-stable components and, further, degrades contrast agents, and EtO requires a subsequent out-gassing step to remove byproducts of the sterilization process, and is also expensive, inflexible and difficult to verify or control.[0006]
• Regardless of whether the syringe is pre-filled, once the set-up is complete, the physician positions a catheter into the patient. The use and type of the catheter varies depending on the procedure being performed. For example, the catheter may be used to deliver contrast agents, using the aforementioned injection device, or to provide a guide for routing bioptomes, ultrasonic imaging probes, or balloon devices.[0007]
• Some of the devices require fluid flow, such as the balloon devices, and are connected to special manual syringes. These special syringes are called “inflators” and use a plunger that is manually advanced using a rod that is threaded into a handle to allow the operator to advance the plunger using very small, controlled increments. However, these threads also give the physician such a mechanical advantage as to take away the “feel” of the balloon inflation. Thus, the physician cannot feel the effect the balloon is having on the wall of the vessel it is stretching. For example, the physician cannot feel a calcium deposit cracking. The special syringes typically include a pressure gauge but it is located on the syringe itself and is impractical for the physician to monitor the gauge as he or she is often watching an image of the balloon being inflated on a monitor. It would be advantageous to use the automatic injection device to accomplish controlled injections of fluid for purposes such as inflating balloons so that a greater degree of inflation accuracy and control is achieved and so a more precise and accurate feedback loop is attained. However, automatic injection devices are generally constructed and arranged to accommodate a large-capacity syringe such as the syringe used to inject contrast agent. This type of syringe is too large to be used for balloon inflation because the injection device cannot move the linear actuator over a short enough distance and with the necessary precision and accuracy for a balloon inflation procedure. Additionally, the larger syringe exhibits greater compliance. To provide the necessary accuracy, a smaller syringe would have to be used so that a given linear distance traveled by the actuator results in a much smaller volume of liquid being injected. However, a small syringe, such as the manual syringe used to inflate a balloon, is not compatible with the present automatic injection devices.[0008]
• There is a need for a device and method for reducing the set-up time associated with using an automatic injection device.[0009]
• There is also a need for a device that minimizes the chances of error by an operator in setting up an automatic injection machine for use.[0010]
• There is a further need for a device and method that improves management of waste while performing catheter-based surgical procedures.[0011]
• There is thus a need for an adapter that would allow the automatic injection device to be used to inject small, precisely measured and controlled amounts of fluid.[0012]
BRIEF SUMMARY OF THE INVENTION
• The present invention includes a method and device for inflating a balloon using an automatic inflation device. The device for inflating a balloon includes a significantly smaller syringe than that typically used in the automatic inflation device. The smaller syringe provides increased control over the administration of a small quantity of fluid. An adapter sleeve is provided that is attachable to an automatic injector device to provide support for the smaller syringe. Present automatic injection devices, such as the CL[0013]100 designed by Acist Medical Systems, Inc. of Eden Prairie, Minn., are designed for large volume injections of contrast media. These devices are designed to accept large syringes. The adapter sleeve, thus, has an outside diameter or dimension substantially equal to that of a syringe used in the device for contrast agents, and an interior diameter or dimension substantially equal to that of the balloon syringe.
• The automatic injector is programmed to provide a balloon inflation mode of operation. Once the sleeve and balloon inflation syringe are installed, the device may be used to automatically fill the syringe with contrast agent or saline. The device may be placed in inflation mode manually, or it may be constructed and arranged to automatically detect the presence of the adapter sleeve and place itself into inflation mode accordingly. Preferably the linear actuator and motor of the automatic injector are used to act on the plunger or “wiper” of the balloon inflation syringe. Alternatively, an adapter may be provided including an auxiliary linear actuator device driven by a linear stepper motor, hydraulic cylinder, piezoelectric inch-worm handheld actuator, or the like.[0014]
• In addition to a physiologic pressure transducer, which provides a pressure input to the monitor for display or other purposes that is representative of biological pressures, one aspect of the invention is a pressure sensor for measuring a pressure representative of the pressure in the balloon. Balloon pressures are significantly higher than biologic pressures. To avoid damaging the sensitive physiologic pressure transducer, the present invention provides a pressure sensor that is separate from the physiologic pressure transducer. This sensor may be a separate pressure transducer, capable of higher pressures. Or it may be an indirect sensor, such as a motor torque detector, which provides a value, representative of motor torque, that can be converted to balloon pressure. Alternatively, strain gauges may be operatively attached to the housing structure surrounding the syringe to measure the axial load on the housing, which is representative of the pressure exerted by the fluid inside the syringe.[0015]
• Another aspect of the invention provides a fluid detection feature. This is a safety feature that insures against air being injected into the patient. This feature may be embodied in a passive coating on the interior surface of the syringe or tubing that reacts when contacted by a fluid. This feature may also be embodied by an active device using ultrasound, optics, or conductivity to determine the presence or absence of fluid in the syringe.[0016]
• The method of using the device to inflate a balloon begins by setting the device to the balloon inflation mode. Again, this preferably occurs automatically when the computer of the automatic inflation device receives a signal from a sensor that is constructed and arranged to detect the presence of the adapter sleeve. The adapter and syringe are then loaded onto the device. Next the balloon catheter is attached and all air is aspirated therefrom and expelled from the system. The balloon and associated tubing are then preloaded with either contrast agent or saline and primed.[0017]
• The balloon and automatic inflation device having thus been prepared, the balloon is inserted into the patient and positioned at the target site. The desired parameters are programmed into the device and inflation is initiated. One aspect of the present invention is that the desired parameters may be calculated automatically based upon inputted data such as patient weight, percent occlusion of the target vessel, type of balloon, etc. Further, the balloon inflation device may perform a small test inflation to determine the elasticity of the artery or vein from which the actual program function is determined.[0018]
• While the balloon is inflating, the inflation speed may either be preprogrammed and allowed to inflate in a fully automatic mode, or controlled from outside or within the sterile field with remote devices such as a handheld device or using a touch screen, in data flow communication with the computer, that is preferably covered with a transparent drape. The balloon pressure, balloon volume, and inflation time are outputted to a display screen. The pressure and volume are preferably also displayed as a graph as a function of time. The balloon pressure and volume are monitored for dilatation. A sudden increase in volume or a sudden decrease in pressure can indicate that a buildup of calcium in a blood vessel has cracked or “popped”, a desired result of balloon therapy for arteriosclerosis. This sudden spike in volume is followed by a subsequent pressure increase indicating a momentary or incremental pressure drop. If the pressure falls below a preset limit, corrected for volume, or is not regained by further inflation, the sudden pressure drop may be indicative that the balloon has ruptured. If it is determined that the balloon has ruptured, the procedure is stopped or reversed automatically or by depressing a stop button on the device.[0019]
• One aspect of the invention provides an automatic detection program that enables the computer controlling the automatic injection device to recognize the occurrence of a “pop” and to stop inflating thereafter, either by deflating the balloon (drawing back on the plunger—aspirating), by holding the balloon pressure constant for a predetermined time (moving the plunger forward under pressure control) or by providing keep-open flow (moving the plunger forward under flow control) or by simply halting motion of the plunger in either direction. This safety feature prevents the possibility of over-inflating the balloon, and thus stressing the blood vessel. The feature can also minimize the unnecessary introduction of fluid into the blood vessel in the event of a balloon rupture.[0020]
• Another aspect of the present invention provides an automatic detection program that measures the actual pressure in the balloon catheter, and the volume of fluid injected, and compares that data to baseline pressure data representative of inflation characteristics of the balloon catheter in controlled environment. The difference between actual data and baseline pressure data represents the effect of the patient on the balloon catheter. This information can be used to determine the effectiveness of the balloon catheter and may also be used to trigger certain actions by the computer. Such actions might include a shut down or aspiration if the data seems to indicate that there is a safety issue, such as a balloon rupture. Another action might be to hold the balloon pressure at a predetermined level for a period of time after a pop has been detected. Another action might be to follow a pressure versus time algorithm previously inputted into the computer. Yet another action executable by the computer is to control the balloon volume, regardless of, or in addition to, balloon pressure.[0021]
• The baseline pressure data will be different for various balloon catheters and is preferably provided in the form of a bar code or other form of computer readable data on or in the package of the balloon catheter. The automatic injection device includes a bar code reader or other correlative device usable to retrieve the baseline pressure data from the package. The computer can also be used to record the balloon pressure as a function of time or volume, baseline pressure as a function of time or volume, injection rate as a function of time, and any other data that the computer may be programmed to use or record so that each procedure, or case, can be recorded as a computer file and used later for analysis or as a record to be inserted into the patient's file.[0022]
• One embodiment provides the capability to create and display three-dimensional graphs that are easily readable by the physician. The third dimension may take the form of a conventional plane—style graph, i.e. a graph having x, y, and z axes. Alternatively a two dimensional plot may be provided using colors or audible tones to provide the third dimension. Example of three dimensional data sets include pressure, volume, and time; pressure, volume, and radiographic balloon opacity; pressure, volume and balloon diameter; and the like.[0023]
• Once the balloon treatment is complete, the balloon is deflated and the catheter is removed from the patient. The device may be stopped or it may be placed in a standby mode and used on another patient. The automatic detection program may include an automatic deflate mode whereby the movement of the syringe plunger is automatically reversed when the “pop” is detected, until it is determined the balloon is deflated. The pressure sensor may be used to determine whether the balloon is deflated.[0024]
• The automatic inflation device, combined with the automatic detection program, makes it possible to inflate multiple balloons simultaneously. By automating the procedure, the physician is free to concentrate on the device monitors and is thus able oversee multiple balloons. The automatic inflation device is further capable of being programmed in a phased manner such that the inflation of various balloons can happen either simultaneously or sequentially.[0025]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a diagrammatic representation of an embodiment of the fluid network of the present invention;[0026]
• FIG. 2 is a diagrammatic representation of an alternative embodiment of the fluid network of the present invention;[0027]
• FIG. 3 is a perspective view of a prior art automatic injector device that is convertible to a balloon inflation device of the present invention;[0028]
• FIG. 3A is a perspective view of an adapter sleeve, useable to convert an automatic injector device into a balloon inflation device of the present invention;[0029]
• FIG. 3B is a perspective view of a prior art injector subassembly of an automatic injection device;[0030]
• FIG. 4 is bottom view of a prior art syringe insertable into an injector device;[0031]
• FIG. 5 is a perspective view of the prior art syringe of FIG. 4;[0032]
• FIG. 6 is a perspective view of a syringe of the present invention surrounded by an adapter sleeve of the present invention shown in phantom lines;[0033]
• FIG. 7 is an embodiment of a balloon inflation device of the present invention;[0034]
• FIGS.[0035]8-10 are examples of pressure graphs shown on a display of the present invention during balloon inflation procedures.
DETAILED DESCRIPTION OF THE INVENTION
• Referring now to the Figures, and first to FIG. 1, there is shown a[0036]fluid network20 comprising adisposable patient manifold22 connected to asaline line24 and anoutput line26. Thesaline line24 has afirst end28 and asecond end30. Thefirst end26 is connected to abag connector32, useable to establish fluid communication between theline24 and asaline bag34.
• The[0037]patient manifold22 is also connected to asyringe36 of an automatic injection device (not shown) for receiving the fluid ejected therefrom. Thepatient manifold22 is thus useable to selectably connect theoutput line26 with either thesaline line24 or thesyringe36. Thepatient manifold22 may be any device capable of selectively directing flow between at least three ports, such as a three-way check valve, a manual or automatic three-way stopcock, a motor operated valve, or a collection of check valves operably disposed within the appropriate lines to effect the desired flow directions. Preferably, thepatient manifold22 comprises an automatic valve that is constructed and arranged such that fluid communication normally exists between thesaline line24 and theoutput line26. However, when a predetermined amount of positive fluid pressure is generated by thesyringe36, the fluid pressure causes the fluid communication between thesaline line24 and theoutput line26 to become blocked, and opens fluid communication between thesyringe36 and theoutput line26. An example of this type of patient manifold is the springloaded spool valve described in U.S. patent application Ser. No. 09/542422, incorporated by reference herein in its entirety. To provide controlled saline pressure when thepatient manifold22 is aligned to deliver saline to theoutput line26, thesaline line24 is fed through a pump, preferably aperistaltic pump62, of the automatic injection device.
• The[0038]output line26 is connected at afirst end38 to thepatient manifold22 and at asecond end40 to a three-way stopcock42. The three-way stopcock42 may be manually or automatically operated and is also connected to awaste line44 and acatheter connector46 such that it may be used to align theoutput line26 with either acatheter48 or thewaste line44.
• The[0039]waste line44 has afirst end50 connected to the three-way stopcock42 and asecond end52 connected to a three-way check valve54. The three-way check valve54 is also connected to anauxiliary syringe56 and abag line58. The three-way check valve54 is constructed and arranged so that theauxiliary syringe56 may be used as a hand pump. When the wiper of thesyringe56 is withdrawn, thecheck valve54 blocks thebag line58 and directs fluid from thewaste line44 into thesyringe56. When the wiper is then advanced, thecheck valve54 blocks thewaste line44 and directs fluid from thesyringe56 into thebag line58. Thebag line58 is connected to awaste bag60 where the waste fluid is deposited. When thesyringe56 is used to aspirate saline into thewaste bag60, it is important that thesaline line24 is not compressed and occluded by theperistaltic pump62.
• Alternatively, as seen in FIG. 2, an[0040]automatic pump70 may be used to pump liquid to thewaste bag60. Theautomatic pump70 is shown as a peristaltic pump that acts on thewaste line44. As peristaltic pumps act on the outside of a tube, thewaste line44 and thebag line58 are integral.
• The[0041]fluid network20 is thus designed to be attached to an automatic injection device quickly and primed with little or no human interaction. Thefluid network20 is assembled, packaged and sterilized so that it may be shipped as a completely assembled kit. Preferably, thewaste bag60 doubles in function as the packaging bag in which all of the aforementioned components of thefluid communication network20 are shipped. This eliminates the need for a separate packaging bag, an added expense. Adivider61 is integrated, preferably by heat sealing, into the bag to limit the amount of fluid that could spill from thebag60 in the event of a leak developing around theconnection63 between thebag60 and thebag line58.
• In use, the[0042]fluid network20 is removed from its packaging and thepatient manifold22 is connected to the syringe of the automatic injection device. Thesaline line24 is threaded through theperistaltic pump62 and verification is made that the three-way stopcock42 is aligned to thewaste line44. Next, thebag line58 is connected to thewaste bag60 and thesaline line24 is connected to thesaline bag34.
• The[0043]fluid network20 is now ready for priming. The automatic injection device, such as thedevice102 shown in FIG. 3 and discussed in more detail below, preferably includes acomputer106 having a program segment for instructing thedevice102 to enter a priming mode. When selected, the priming mode program segment includes a command that causes thecomputer106 to align thepatient manifold22 for contrast agent, or if thepatient manifold22 is a manually operated valve, displays a message instructing the operator to do so. The program segment prevents further action unless thecomputer106 receives verification from the operator that the manifold22 is aligned. Preferably, a patientmanifold position detector72 is operably connected to the manifold22 and in communication with thecomputer106, obviating the need for verification from the operator. Once the position of the manifold22 is verified, either by operator input or with thedetector72, the program segment causes thecomputer106 to send a signal to the linear actuator of the automatic injector that advances the plunger of thesyringe36 slightly to force potential air bubbles from the syringe connecting tube66, which connects thepatient manifold22 to thesyringe36. Any air bubbles in the connecting tube66 are forced into theoutput line26.
• The priming program segment[0044]64 then aligns thepatient manifold22 for saline. Aftermanifold position detector72 verifies that thepatient manifold22 is aligned for saline, theperistaltic pump62 is activated for a predetermined interval. The interval is long enough, for a given pump speed, to fill thesaline line24, thepatient manifold22 and theoutput line26 with saline.
• Preferably, the[0045]peristaltic pump62 operates in a priming mode whereby it turns in a stutter fashion to send pressure pulses through the various lines. These pressure pulses act to dislodge air bubbles from the inner walls of the lines, thus obviating the need for the operator to tap on the lines during the priming procedure. To monitor for the presence of bubbles, abubble detector74 is placed in one or more locations and are electrically connected to the computer of the automatic injector. In priming mode, detection of bubbles is expected. However, when the injector is in injection mode, the receipt of a signal from the bubble detector(s)74 will cause the injector to stop forward movement of the plunger of thesyringe36. Thewaste bag60 eventually receives all of the priming fluid.
• Alternatively, if a syringe pump (not shown) is used instead of a[0046]peristaltic pump62, the syringe may be operated by a linear actuator in a stutter fashion such that the linear actuator intermittently hammers on the plunger of the syringe thereby creating the necessary pressure pulses to dislodge air bubbles from the inner walls of the various lines. One skilled in the art will see that any pump substituted for theperistaltic pump62 can be operated in an on and off fashion to create such pressure pulses.
• Priming having thus been completed, the attending physician may insert the[0047]catheter48 into the target blood vessel and attach thecatheter48 to thefluid communication network20 using thecatheter connector46. Thecatheter48 is then primed, and proper placement within the vessel is verified, by taking a suction on thecatheter48 until blood appears in the clear tubing of theoutput line26. Taking suction on thecatheter48 is performed by aligning the stopcock42 to establish fluid communication between theoutput line26 and thecatheter48. Suction may then be drawn on theoutput line26 by retracting the plunger of thesyringe36, or reversing the rotation of theperistaltic pump62. However, it may be undesirable to establish reverse fluid flow into thesyringe36 or thesaline bag32. Doing so prevents reuse of the saline remaining in thesaline bag34 and reuse of the contrast agent in thesyringe36. More preferably, theoutput line26 includes adisconnect68 that allows the physician to connect a hand syringe to theoutput line26 and take a suction thereon. Once blood appears in theclear output line26, thedisconnect68 is reconnected and the three-way stopcock42 is aligned to thewaste line44. Theperistaltic pump62 is then run in a forward direction to force the blood from theoutput line26, through the stopcock42, and into thewaste line44. Thewaste bag60 receives the blood and other waste fluids for safe containment and easy disposal.
• Referring now to FIGS. 3, 3A, and[0048]3B, another embodiment of the present invention provides an automaticballoon inflation device100. This embodiment of theballoon inflation device100 is constructed and arranged to allow an existingautomatic injection device102, such as the CL100 made by Acist Medical Systems, Inc. of Eden Prairie, Minn. and described in U.S. Pat. No. 6,099,502 incorporated by reference herein in its entirety. It is understood by one skilled in the art that a separate balloon inflation device could be constructed using the devices and techniques represented herein combined with the necessarily associated functionality of existing angiographic injectors.
• The[0049]automatic injection device102 is converted into aballoon inflation device100, when it is accessorized to accept a small, balloon inflation syringe104 (FIGS. 6 and 7), and when thecomputer106 of theinjection device102, is updated with a program that allows theinjection device102 to operate in “Inflation Mode”.
• The example of an[0050]automatic injection device102 shown in FIG. 3 includes aninjector subassembly108 and a user-interface subassembly110. Theinjector subassembly108 includes asyringe holder112, typically used to house a relativelylarge syringe body114 having fluid capacities on the order of 10 cc to 250 cc, such as those used for angiography and shown in FIGS. 4 and 5. Thesyringe body114 is equipped with aplunger116, slideably disposed therein. The plunger is acted upon by a linear actuator118 (FIG. 3) of the injector subassembly and is removably attached thereto. The particularangiography syringe body114 shown in FIGS. 4 and 5, is fully described in U.S. Pat. No. 6,099,502 and includes features that an automatic injection device, the injector subassembly of which is shown in FIG. 3B. These features are discussed briefly herein as they provide examples of injector-specific considerations that are made in the design of a conversion kit to allow theinjector102 to be used as aballoon injector100. These features may also be incorporated into the design of aballoon inflation syringe104.
• Thus, the[0051]angiography syringe114 includes awall119 defining first and second opposite ends122, and124. Thefirst end122 corresponds to a distal end of thesyringe114, and thesecond end124 corresponds to a proximal end of thesyringe114. Thewall119 of thesyringe114 is cylindrical in the illustrated embodiment and includes acentral axis126 extending longitudinally therethrough.
• The[0052]syringe body114 defines apumping chamber128 in an interior thereof. A wiper orplunger116 is located in thepumping chamber128 and is constructed and arranged for reciprocal motion between a position adjacent to thefirst end122 and thesecond end124. That is, when thesyringe114 is mounted in a system analogous to theangiographic system102, thelinear actuator118 from the system energizes theplunger116 and causes it to move between thesecond end124 and thefirst end122. Aplunger support member130 supports theplunger116. Thesupport member130 preferably comprises a rigid, hard material, for example, a polycarbonate or ABS plastic, to interface between an actuator118 and theplunger116. Themember130 attaches to theplunger116 by a snap fit, a magnetic fit, or a similar quick attach coupling that allows theplunger116 to be pushed and pulled.
• The[0053]syringe114 defines at least one port for providing fluid flow communication with thepumping chamber128. In the particular embodiment illustrated, thesyringe114 includes two ports providing fluid flow communication with thepumping chamber128. Specifically, aninlet port132 allows thepumping chamber128 in thesyringe114 to be filled with contrast material, and purged of air through theinlet port132. Ahousing134 circumscribes theinlet port132 and allows theinlet port132 to be connected with an appropriate bottle or bag136 (FIGS. 3 and 3B) of contrast agent or saline. When thesyringe114 is oriented in asyringe holder112 in an angiographic system as described above, theinlet port132 is located above thepumping chamber128.
• The[0054]inlet port housing134 is preferably clear because one aspect of the present invention provides a fluid detection device76 (FIG. 1) that is preferably operably connected to thehousing134. The device ensures that all air has been purged from thesyringe114 and that fluid occupies thehousing134. The fluid detection device may be embodied in a passive coating on the interior surface of the syringe that reacts when contacted by a fluid. Alternatively, the device may be embodied using an ultrasound, optic, or electromagnetic emitter to detect the presence of fluid in thehousing134. One embodiment provides an optic sensor used to determine the position of a floating ball of a floating ball valve. When the ball is supported by fluid in an up position, any air in thesyringe114 has been purged. Though thesyringe114 shown in FIGS. 4 and 5 is denoted as prior art, as mentioned above, thefluid detection device76 is considered a novel aspect of the present invention.
• In this embodiment, the[0055]syringe114 is mounted in an angiographic system at an angle such that any air bubbles present in thepumping chamber128 migrate toward theinlet port132, through which they may be purged. To purge air through theinlet port132, theinlet port housing134 houses a valve assembly that permits air to be expelled or purged from thesyringe114, but does not allow fluid to flow out of thepumping chamber128 and back into thebottle136 of contrast fluid when pressure movement is applied on the syringe side of the check valve. Such a check valve is described in U.S. Pat. No. 6,099,502.
• The[0056]syringe114 also includes anoutlet port138 in fluid flow communication with thepumping chamber128. Theoutlet port138 permits fluid flow from thepumping chamber128 to a fluid communication network, such asfluid network20. Theoutlet port138 is surrounded, or circumscribed, by anoutlet port housing140 extending, or projecting, from the end wall of thesyringe114. Theoutlet port housing140 is constructed and arranged to receive a patient manifold connector tube142 (FIG. 1).
• The[0057]syringe body114 is too large for use as a balloon inflation syringe. However, thesyringe holder112 is constructed and arranged specifically to hold aparticular syringe body114. Thus, to place a balloon inflation syringe in the syringe holder and provide proper alignment with relation to thelinear actuator118, and provide the necessary support needed to operate a relatively thin-walled balloon inflation syringe with a powerfullinear actuator118, the present invention provides anadapter sleeve120, shown in FIG. 3A and in phantom in FIG. 6, constructed and arranged with outer dimensions that allow thesleeve120 to be properly cradled by thesyringe holder112. The inside cavity of the adapter sleeve is configured to closely mate with aballoon inflation syringe104.
• The[0058]balloon inflation syringe104 is preferably closely analogous to theangiographic syringe114, to allow attachment of theballoon inflation syringe104 to theinjector subassembly108. Thus, theballoon inflation syringe104 includes a wall that defines apumping chamber146 therein that is an appropriately small size to allow controlled balloon inflation, typically on the order of 5 ml to 40 ml. Thesyringe104 also includes aplunger148 that attaches to thelinear actuator118 in the same manner as theplunger116 of thesyringe114. Aninlet port150, defined by aninlet port housing152, establishes fluid communication between thesupply bottle136 and thepumping chamber146. Theinlet port housing152 is longer than the analogousinlet port housing134 of theangiographic syringe114 to allow for the smaller diameter of theballoon inflation syringe104. Anoutlet port154 defined by anoutlet port housing156, establishes fluid communication between thepatient manifold connector142 and thepumping chamber146 of theballoon inflation syringe104.
• Similar to the[0059]ports132 and138 of theangiographic syringe114, described above, theinlet port150 and theoutlet port154 of theballoon inflation syringe104 are located in upper portions and lower portions of thesyringe104 when thesyringe104 is loaded into theinjector device100. However, as much less fluid is being injected, and it is very rare to inject all of the fluid located in thepumping chamber146 during a balloon inflation procedure, there may be less importance placed on the location of theports150 and154. For example, theballoon inflation syringe104 may be supplied pre-loaded with fluid, obviating the need for aninlet port150. Further, theoutlet port154 may be more conventionally located along a central axis of thesyringe104, so long as theparticular injection device100, to which theadapter sleeve120 is designed, accommodates the placement of theoutlet port154.
• Referring again to FIGS. 3A and 6, the[0060]adapter sleeve120 is described in greater detail. Theadapter sleeve120 has anouter wall158 defining aninner cavity160 having an inside diameter substantially equal to the outside diameter of theballoon inflation syringe104. Theouter wall158 is open at afirst end162 and asecond end164 such that theballoon inflation syringe104 may be loaded into thefirst end162 and so that thelinear actuator118 may act on theplunger148 of thesyringe104 through thesecond end164. Theouter wall158 also defines agroove166 at thefirst end162 that is constructed and arranged to accept theinlet port housing152. FIG. 6 shows that when thesyringe104 is mated with thesleeve120, the size and shape of the resulting assembly is substantially the same as the size and shape of theangiographic syringe114.
• FIG. 7 shows an alternative embodiment of a[0061]balloon inflation device170. Theballoon inflation device170 is a self-contained unit that is attachable to anautomatic injection device102. This arrangement obviates the need for switching syringes and inserting adapter sleeves when transitioning from a diagnostic imaging procedure to a balloon catheter procedure. Additionally, providing theballoon inflation device170 as a self-contained unit allows for the use of common electronics and controls to be used for supplying power and commands to the mechanical components of thedevice170.
• The[0062]balloon inflation device170 includes an appropriatelysized syringe172 operably attached to alinear actuator module174. Thelinear actuator module174 contains an actuating device, such as a motor or hydraulic or pneumatic piston, useable to move aplunger176 slideably disposed within thesyringe172.
• The linear actuator module is able to receive and respond to commands given by the[0063]computer106 of theautomatic inflation device102, and receive the necessary power to drive the actuating device, through connector pins178.
• An advantage to providing a computer driven balloon inflation device, such as[0064]balloon inflation device100 or172, is that the device can become integrated into a closed feedback loop that can be used to accurately achieve desired pressures within a balloon catheter during an inflation procedure. Referring back to FIG. 1, there is shown apressure transducer180 located within thefluid communication network20 on thesaline line24. Thepressure transducer180 is a sensitive instrument, capable of measuring small changes in pressure, such as those pertaining to biological patient attributes. Locating thepressure transducer180 on thesaline line24 allows thepatient manifold22 to be used to insulate thetransducer180 from any high pressures that may be generated by thesyringe36.
• A pressure sensor, such as the[0065]strain gauge182, shown in FIG. 7, can be used for high pressures, such as those developed by theballoon inflation syringe104. Thestrain gauge182 is mounted to one of foursyringe support rods184 that are used to fix thesyringe172 to thelinear actuator module174. Balloon pressure may be accurately determined by measuring the amount of strain encountered by thesupport rods184 as theplunger176 is depressed. Alternatively, pressure may be measured as a function of the load placed on thelinear actuator module174. For example, if a DC motor is used to drive the linear actuator of themodule174, a circuit may be incorporated into the electronics driving the motor that is constructed and arranged to measure motor torque as a function of current drawn.
• The feedback loop is formed by measuring balloon pressure and providing it to the[0066]computer106, which then uses it to increase or decrease the amount of pressure it instructs thelinear actuator module174 orlinear actuator118 to place on theplunger176 or148, respectively. A significant advantage to forming a computerized feedback loop is the ability to load a program segment into the memory of thecomputer106 that provides a target map to be used by thecomputer106 for calculating error and determining corrective action. Another program segment can be used to create a display of target pressure and actual pressure, either numerically or graphically.
• Referring now to FIGS.[0067]8-10, there are provided examples ofdisplays182 showing pressure versus time graphs184 (units and values have been omitted but are understood to be included in an actual display). A similar graph may be provided for balloon volume versus time (not shown).
• FIG. 8 shows a[0068]display182 with agraph184 that may represent a typical balloon inflation pressure profile when a balloon is used to dilate an area in a blood vessel that has become restricted due to a build-up of plaque. At186, the balloon is inflating and pressure is rising steadily as the fluid meets with increasing resistance from the balloon and the walls of the vessel. The dottedline188 represents the particular inflation characteristics of the balloon catheter being used in the procedure. This will be discussed in more detail below.
• Typically during this procedure, there will be a sudden drop in[0069]pressure190. This is known as a “pop” and it represents the plaque buildup giving way, the ultimate goal of the procedure. By breaking the bonds that hold the plaque together, the vessel is allowed to return to a diameter closer to that of its original size. When a balloon is being inflated manually, the physician pays attention to feeling this “pop” in the syringe being used to inflate the balloon. With the feedback loop of the present invention, a program segment is provided that allows thecomputer106 to sense this “pop” and take a desired action thereafter. The graph in FIG. 8 shows that the desired action in this case was to deflate the balloon at192.
• FIG. 9 shows a[0070]similar graph184. However, in this case, the desired action after the “pop” at190 is to hold the pressure in the balloon constant at192 for a predetermined period oftime194. The feedback loop is thus used to move theplunger148 appropriately to maintain a constant pressure in the balloon.
• It is not uncommon to encounter a clot that may be broken more than once as a balloon catheter stretches it. FIG. 10 shows a[0071]graph184 where a plurality of “pops” are encountered at190a,190b, and190c. Here the program segment loaded into thecomputer106 either specified a maximum pressure to be achieved, or a maximum volume to be achieved, given the pressure and volume limits of the balloon and/or the size constraints of the vessel. Alternatively, the program segment allows the device to be used in a manual mode, with safety limits set on pressure and volume. In manual mode the physician uses a hand control196 (FIG. 3) to control the inflation of the balloon, while viewing thedisplay182 for visual indication of the occurrence of a “pop” at190. Additional stimuli may be provided to the physician such as a tactile feedback mechanism, such as a vibration or a proportional force feedback, in thehand control196, or an audible tone provided by a speaker in themonitor182. Additionally, a program segment may be provided that allows a physician to inflate the balloon manually, while “recording” flow rates, volumes and pressures used, so that thecomputer106 may “learn” how the physician inflated the balloon. The physician may then instruct thecomputer106 to repeat the inflation techniques he or she just performed. There are many instances where multiple inflations must be performed and this feature allows the physician to replicate a desired inflation automatically.
• FIG. 8 shows a[0072]dotted line188 that represents a baseline pressure profile of a particular balloon catheter in a no-load environment. One aspect of the present invention provides a bar code reader198 (FIG. 7), or similar data input device, that is useable to input a pressure profile. The balloon catheter manufacturer supplies the profile, preferably as a bar code on the catheter packaging, of the baseline no-load inflation characteristics of the balloon catheter contained therein.
• Knowing the baseline pressure characteristics of the balloon catheter allows the physician to view the difference between the actual, loaded pressure plot and the[0073]baseline graph188. The difference is attributed to the resistance to inflation exhibited by the blood vessel.
• The foregoing description addresses embodiments encompassing the principles of the present invention. The embodiments may be changed, modified and/or implemented using various types of arrangements. Those skilled in the art will readily recognize various modifications and changes that may be made to the invention without strictly following the exemplary embodiments and applications illustrated and described herein, and without departing from the scope of the invention, which is set forth in the following claims.[0074]

Claims (39)

What is claimed is:

1. A tubing network, attachable to an automatic injector device, comprising:

a fluid bag connector;

a first line connected at one end to the fluid bag connector;

a patient manifold connected to the other end of the first line and connectable to the automatic injector device for fluid communication therewith;

a second line connected at one end to the patient manifold such that the patient manifold is usable to selectively port fluid from either the automatic injector device or the first line, to the second line;

a stopcock capable of performing as a three-way stopcock, connected to a second end of the second line, useable to connect the second line to a catheter;

a waste line attached at a first end to the three-way stopcock such that the waste line is in selectable fluid communication with the second line;

a pump operably connected to a second end of the waste line for taking suction thereon;

a bag line connected at a first end to the pump such that the bag line receives pumped fluid when the pump is operating; and,

a waste bag operably connected to a second end of the bag line.

2. The tubing network ofclaim 1 wherein said pump comprises a manual pump.

3. The tubing network ofclaim 1 wherein said pump comprises a syringe.

4. The tubing network ofclaim 3 further comprising a three-way check valve having three ports, the first port operably connected to the inlet line, the second port operably connected to the syringe, and the third port operably connected to the bag line, the valve constructed and arranged such that when a plunger of the syringe is withdrawn to create suction within the syringe, the fluid is allowed to enter the first port and exit the second port and fluid is prevented from entering the valve through the third port, and such that when the plunger of the syringe is advanced, thereby forcing fluid from the syringe, fluid is allowed to enter the valve through the second port and exit the valve through the third port, while fluid is restricted from exiting the valve through the first port.

5. The tubing network ofclaim 1 wherein said pump comprises a peristaltic pump and said waste line is integral with said bag line.

6. The tubing network ofclaim 1 wherein said patient manifold comprises a three-way stopcock.

7. The tubing network ofclaim 1 wherein said patient manifold comprises a three-way check valve.

8. The tubing network ofclaim 1 wherein said patient manifold comprises an automatic valve constructed and arranged such that fluid communication normally exists between said first line and said second line and such that when a predetermined amount of positive fluid pressure is generated by the automatic injector device, the fluid pressure causes a passageway between the first line and the second line to become blocked and opens a passageway between the automatic injector device and the second line.

9. The tubing network ofclaim 1 wherein said patient manifold comprises a check valve operably connected to the first line, thereby allowing flow from the bag connector to the second line and blocking flow from the second line to the bag connector.

10. The tubing network ofclaim 9 wherein said patient manifold further comprises a check valve operably connected to the automatic injector device, thereby allowing flow from the automatic injector device to the second line and blocking flow from the second line to the automatic injector device.

11. The tubing network ofclaim 9 wherein said patient manifold further comprises a check valve operably connected to the second line, thereby allowing flow from the one end of the second line to the stopcock and blocking flow from the stopcock to the one end of the second line.

12. The tubing network ofclaim 1 wherein said patient manifold comprises a motor operated valve, controllable by a computer of said automatic injector device.

13. The tubing network ofclaim 1 further comprising a packaging bag, useable to contain and maintain sterility of said fluid bag connector, said first and second lines, said patient manifold, said stopcock, said waste line, said pump, and said bag line, during shipping of said tubing network.

14. The tubing network ofclaim 13 wherein said packaging bag is further useable to contain and maintain sterility of said waste bag.

15. The tubing network ofclaim 13 wherein said packaging bag is useable as said waste bag after said packaging bag is opened and emptied.

16. The tubing network ofclaim 15 wherein said packaging bag comprises a connector useable to establish fluid communication between said bag line second end and said packaging bag.

17. The tubing network ofclaim 1 further comprising a check valve operably connected to said waste line allowing flow from said stopcock to said pump and preventing flow from said pump to said stopcock.

18. The tubing network ofclaim 1 further comprising a check valve operably connected to said bag line allowing fluid flow from said pump to said waste bag and preventing fluid flow from said waste bag to said pump.

19. A method of purging air bubbles from a medical tubing network comprising:

operably attaching the fluid network to a fluid pump;

causing the fluid pump to send a plurality of pressure waves through the fluid network, thereby causing bubbles adhered to the fluid network to become dislodged;

directing fluid used as a medium to carry said pressure waves to a waste container.

20. The method ofclaim 19 whereby causing the fluid pump to send a plurality of pressure waves comprises commanding the pump to start and stop intermittently.

21. The method ofclaim 19 whereby operably attaching the fluid network to a fluid pump comprises threading a tube of the tubing network through a peristaltic pump.

22. The method ofclaim 19 whereby operably attaching the fluid network to a fluid pump comprises operably connecting the fluid network to a motor-operated syringe.

23. The method ofclaim 22 whereby causing the fluid pump to send a plurality of pressure waves through the fluid network comprises causing a plunger of the syringe to move through the syringe in a stuttering hammer motion.

24. A method of inflating a balloon catheter comprising:

a) injecting fluid into the balloon catheter at a predetermined rate;

b) receiving actual pressure data;

c) comparing the actual pressure data to baseline pressure data representative of inflation characteristics of the balloon catheter in a controlled environment;

d) adjusting the inflation rate in response to the difference between the actual pressure and the baseline pressure.

25. The method ofclaim 24 further comprising:

monitoring for a pressure drop of a predetermined magnitude;

holding pressure constant in said balloon for a predetermined time after said pressure drop.

26. The method ofclaim 24 further comprising:

monitoring for a pressure drop of a predetermined magnitude;

deflating said balloon after said pressure drop;

withdrawing the balloon catheter.

27. The method ofclaim 24 further comprising:

operably attaching a computerized inflation device to the balloon catheter;

programming the computer to perform the steps a), b), c), and d).

28. The method ofclaim 24 further comprising:

e) recording the actual pressure data as a function of time.

29. The method ofclaim 28 further comprising:

f) recording the baseline pressure data as a function of time.

30. The method ofclaim 28 further comprising:

f) recording the injection rate as a function of time.

31. The method ofclaim 27 wherein said predetermined rate of step a) comprises an algorithm providing varying injection rates as a function of time.

32. The method ofclaim 24 further comprising:

e) defining data safety limits;

f) activating an alarm when the actual pressure data falls outside said safety limits.

33. An automatic medical balloon inflation device comprising:

a fluid pump, attachable to a balloon catheter, and capable of providing fluid pressure to a balloon at a distal end of the balloon catheter;

a computer, operably attached to the pump, and capable of controlling the fluid pressure created by the pump;

a pressure detector, operably attached to the computer, and capable of providing data to the computer corresponding to the fluid pressure created by the pump.

34. The automatic medical balloon inflation device ofclaim 33 further comprising a program segment, stored in a computer readable medium readable by said computer, that when executed enables said computer to determine the existence of predetermined characteristics of the data received by the computer from the pressure detector, and to react to the characteristics in a predetermined manner.

35. The automatic medical balloon inflation device ofclaim 33 further comprising a monitor operably connected to the computer and capable of displaying data representative of the data received from the pressure sensor.

36. The automatic medical balloon inflation device ofclaim 35 further comprising a program segment, stored in a computer readable medium readable by said computer, that when executed enables said computer to send signals to the monitor to display a graph of fluid pressure versus time.

37. The automatic medical balloon inflation device ofclaim 30 further comprising a program segment, stored in a computer readable medium readable by said computer, that when executed enables said computer to send signals to the monitor to display a graph of balloon volume versus time.

38. The automatic medical balloon inflation device ofclaim 34 further comprising a second program segment, readable by said computer, enabling said computer to receive data representative of baseline inflation characteristics of a balloon catheter under a no-load condition, such that said computer is useable to compare data representative of actual inflation characteristics against said baseline data.

39. The automatic medical balloon inflation device ofclaim 38 further comprising a bar code reader useable to upload said baseline data into said computer.

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