Acoustic line tracing system and method for fluid transfer system

An acoustic line tracing system for tracing a fluid transfer system tubing line includes an acoustic receiver operably connectable to the tubing line and configured to receive the vibratory signal. The acoustic receiver includes a vibration sensor disposed to contact the tubing line and configured for detecting vibration of the surface of the tubing line caused by the vibratory signal, and an indicator producing at least one of an audio and a visual cue when the vibration sensor detects the vibratory signal.

FIELD OF THE INVENTION

The present invention relates to a system and method for tracing a particular tubing set from end to end, more particularly to a system and method that uses acoustic vibration to trace a tubing system for fluid transfer, and even more particularly to a system and method for tracing tubing systems used in the medical industry for transfer of fluids, such as intravenous infusion tubing, using acoustic vibration.

BACKGROUND

Errors in administration of medication through a fluid transfer system, such as a patient infusion system or an automatic compounder, can result from many causes, including misconnections. Accordingly, to reduce the potential for such errors, professional guidelines and/or standard operating procedures require clinicians, such as nurses and pharmacists, to perform “line management,” also known as line tracing, numerous times throughout their working shifts. In the case of an automatic compounder, line management involves verifying each medication source container is routed through tubing to the correct input of the mixing manifold and pump. In the case of a patient infusion system, line management involves verifying that each medication source container, typically a bag, bottle, or syringe, is routed through tubing to the correct catheter, and that the tubing is associated with the correct pump channel (if an infusion pump is used). The activity further includes verifying that it is safe to join two or more tubing segments containing different medications and/or flowing at different rates. By way of example, a nurse or other clinician may perform line management for each patient when starting a shift, when receiving a patient from another facility, another area of the hospital, or a different clinician, and just prior to administration of an intravenous medication. Repeated performance of the detailed line management procedure imposes a time burden on the clinicians, and is prone to errors, particularly as the complexity of a patient's overall infusion tubing system increases. That is, multiple tubing sets, medications, junctions, access ports, pump channels, and catheters increase the amount of time required to perform line management and also introduce additional opportunities for error in line management.

To facilitate line management, clinicians often manually label infusion setups at various locations throughout the tubing system. Generally, the labeling is crude, using materials on hand such as medical tape wrapped around the tubing and labeled with identifying information such as the medication name. This labeling is repeated at several points throughout the system. For example, labels may be placed at the spike end of a tubing set, at the catheter connection, at each access port and junction, on the roller clamp and slide clamp, on the catheter, on the pump channel itself, and on the medication container. When applying such labels, a clinician manually slides his or her hand along the tube, progressing from a first tube end to a second tube end, and labeling desired points along the length of the tube.

Line management systems should be capable of identifying the correct line, catheter, and connector prior to connecting any new medicine container and line or prior to injecting a medication into an existing access port. Additionally, the system should allow a user to correctly identify a container and its corresponding line and pump interface before loading the tubing line into the pump. The system should also maintain clear physical and visual association among the container, line, pump, and catheter. Proposed systems for facilitating the line management process include color coding of the tubing sets used in the infusion system, use of the tubing as an optical waveguide similar to glass or plastic optical fibers, and use of electrically conducting wires embedded in the wall of the tubing. Each of these solutions provides some advantages, but a primary disadvantage to each proposal is that it would require development of a specialized tubing set.

Accordingly, there is a need for a system that facilitates accurate line management without the need for development of new tubing systems.

SUMMARY

An improved acoustic line tracing system addresses these needs. The acoustic sensor system allows for accurate tracing of a line, without the need for developing a specialized tubing set. Accordingly, existing tubing sets, with known physical characteristics can be used with the acoustic tracing system.

In a first aspect, an acoustic line tracing system for tracing a fluid transfer system tubing line includes an acoustic receiver operably connectable to the tubing line and configured to receive a vibratory signal. The acoustic receiver includes a vibration sensor disposed to contact the tubing line and configured for detecting vibration of the surface of the tubing line caused by the vibratory signal, and an indicator producing at least one of an audio and a visual cue when the vibration sensor detects the vibratory signal.

In another aspect of the invention, an acoustic line tracing system for verifying continuity of a tubing set in an infusion system includes a first acoustic receiver connectable to the tubing line and configured for receiving a vibratory signal. The first acoustic receiver has a vibration sensor disposed to contact the tubing line and configured for detecting vibration of the surface of the tubing line caused by the vibratory signal. A signal transmitter operatively contacts the tubing set and is electrically coupled with the first acoustic receiver. The signal transmitter is configured for generating acoustic vibrations in the tubing line when the sensor detects a vibratory signal. A second acoustic receiver is connectable to the tubing line and configured for receiving the acoustic vibrations generated by said signal transmitter. The second acoustic receiver includes a sensor disposed to contact the tubing line and configured for detecting vibrations in the surface of the tubing line caused by the acoustic vibrations, and an indicator producing at least one of an audio and a visual cue when the vibration sensor detects the vibrations. The first acoustic receiver and the signal transmitter are separated by at least one vibration dampening component.

In still another aspect of the invention, a method for tracing a tubing set to determine set continuity includes a step of providing an acoustic receiver in contact with the tubing set at a first position along the tubing set. The acoustic receiver has a vibration sensor operatively that is in contact with the tubing set and capable of sensing vibrations in the tubing set, and an indicator capable of producing at least one of an audio and a visual cue when said vibration sensor detects the vibrations. The method further includes a step of inducing a vibratory signal at a second position along the tubing set, and a step of detecting, using the provided acoustic receiver, whether or not the vibratory signal is received at the first position along the tubing set. The method also includes a step of determining whether the tubing set is continuous between the first position and the second position, where the tubing set is determined to be continuous if the vibration sensor detects the vibratory signal at the detecting step. The indicator produces the audio and/or visual cue when it is determined that the tubing set is continuous.

DETAILED DESCRIPTION

Referring now toFIGS. 1 and 2, a fluid transfer system is shown schematically as infusion system10. WhileFIGS. 1 and 2show the fluid transfer system as patient infusion system10, those of skill in the art will recognize that other fluid transfer systems, such as automatic compounder systems, are within the scope of the present invention. The infusion system10includes a medication container12, a catheter14for connection to a patient, and a tubing set16providing fluid communication between the medication container12and the catheter14. The infusion system10can be a so-called “gravity-fed” pumpless system as shown inFIG. 1, or optionally includes an infusion pump18for pumping the medication from the container12through the tubing set16and catheter14into a patient as shown inFIG. 2. While the systems10shown inFIGS. 1 and 2include equipment for delivering a single medication for clarity, those of skill in the art will recognize that an infusion system may include multiple containers, catheters, pumps, and tubing sets.

The medication container12can be, for example, a bag, bottle, syringe, or other standard container used to contain liquid medications. There is no particular restriction regarding what containers may be used. A drip chamber20is preferably disposed directly downstream from the medication container12. The drip chamber20allows gas to separate from fluid exiting the medication container12, thus helping to prevent an air embolism, and also helps a clinician estimate the flow rate of the medication by allowing the clinician to count the number of drops of the medication that enter the drip chamber20in a given period of time.

The catheter14can be any standard equipment for use with a patient. The catheter14may be, for example, a temporary catheter inserted into a peripheral vein, a peripherally inserted central catheter, a central venous catheter, or other catheter known to those in the art. Likewise, the tubing set16is any standard tubing set used to connect the medication container12to the catheter14.

As shown inFIG. 2, the infusion pump18is any known pump used to administer fluid intravenously. The pump18is used to help regulate fluid flow through the system10, and may be used to vary an infusion rate based on, for example time and/or patient demand. The pump18is positioned between the drip chamber20and the catheter14, and may include one or more “channels,” with each channel used to regulate fluid flow from a distinct medication container through a distinct tubing set.

FIGS. 1 and 2each show at least one acoustic receiver22connected to an exterior surface of the tubing set16. The acoustic receiver22is a device capable of detecting acoustic waves transmitted through the tubing set16. The receiver22is preferably removably secured to the tubing set16, such that a clinician can position the receiver at any desired position along the length of the tubing set, and can move the receiver from one tubing set to another as desired. WhileFIG. 2shows the acoustic receiver22as a separate device, artisans will recognize that the receiver can optionally be incorporated into the pump18as an integrated acoustic receiver disposed at one or both of the upstream and downstream sides of the pump without departing from the scope of the invention. Alternatively, the receiver22is optionally formed as an integral portion of the tubing set16, disposed near the medication container12and/or near the catheter14. Alternatively, the receiver22is optionally formed as an integral portion of the infusion system10, including the medication container12and/or the catheter14.

As shown inFIG. 3, the acoustic receiver22includes a sensor24, an indicator26, and a power source28. The sensor24, such as a vibration sensor is disposed in contact with the tubing set16, and is used to detect an acoustic vibratory signal transmitted through the tubing set16. In the preferred embodiment, the sensor24is a transducer capable of converting vibrations from the tubing set16into an electrical signal. For example, the sensor24is optionally a microphone such as a contact microphone or other piezoelectric device.

The sensor24is electrically connected to the indicator26, which provides at least one of an audio and a visual or other indication when the sensor24detects sound waves. The indicator26is preferably a small indicator light such as a light emitting diode, a small loudspeaker capable of emitting an audible tone, or other device capable of providing an observable signal to a clinician.

The power source28provides power to the receiver22. The power source28is preferably a compact portable power source such as a battery. However, other sources, such as a connection to mains power, photovoltaic panels, and the like may be used without departing from the scope of the invention.

The receiver22is preferably removably connected to the tubing itself and/or any component of the tubing set16, such as the drip chamber20and/or access ports. Alternatively, the receiver22can be connected to other portions of the infusion system10, including the medication container12or the catheter14. This connection is formed by, for example a spring-biased clamp. The force exerted on the tubing set16by the receiver22is desirably sufficient for maintaining steady contact between the sensor24and the tubing set, so that an accurate reading can be performed. However, the biasing force retaining the receiver22in place should not be so strong as to occlude the tubing set16.

Turning now toFIG. 5, the signal sensed by the acoustic receiver22is preferably provided, for example, by a signal transmitter30preferably removably connected to the tubing set. The transmitter30may be any device capable of producing a vibratory acoustic signal, preferably an ultrasound signal having a frequency greater than 20 kHz. In the preferred embodiment, the transmitter30includes a piezoelectric device configured for generating ultrasonic acoustic vibrations. The transmitter30can be a separate device, or optionally can be incorporated into the tubing set16. Alternatively, the transmitter30can optionally be attached to or formed integrally with other elements of the infusion system10, including the medication container12and/or the catheter14. As shown inFIG. 5, the transmitter30can also optionally be incorporated into the infusion pump18as an integrated signal transmitter18a. WhileFIG. 5shows integrated signal transmitter18adisposed on the downstream side of the pump18, those of skill in the art will recognize that an integrated signal transmitter can be disposed at one or both of the upstream and downstream sides without departing from the scope of the invention. Alternatively, a pumping mechanism of the infusion pump18can be the signal transmitter30. While in the depicted embodiment, the signal transmitter30is separate from the acoustic receiver22, it is also contemplated that the acoustic receiver22is also optionally capable of generating an acoustic vibratory signal, thus operating as a signal transmitter/receiver or “transceiver”. As a further alternative, the vibratory signal may be generated manually, for example by a clinician tapping the tubing set using, for example, a finger or other implement. The vibratory acoustic signal is preferably applied at a location13distant from the receiver22, so that opposite ends of the tubing set16are determined to be continuous. As examples,FIG. 1shows the vibratory signal can be applied to the tubing set16at the location13disposed proximate to the medication container12, while the receiver22is positioned proximate to the catheter14;FIG. 2shows the vibratory signal applied at a location13downstream from the pump18, with the receiver22positioned near the catheter14; andFIG. 5shows the vibratory signal applied at the position13near the medication bag, with a first receiver22positioned upstream of the pump18.

In practice, to aid in creation of an infusion mapping, a vibratory signal is provided at a first end of the tubing set16. The signal is optionally provided continuously or intermittently (e.g., a pulsed signal). The acoustic receiver22is then systematically connected to each of a plurality of candidate tubes at a second end of the infusion system10, until the vibratory signal is detected by the sensor24at the tube which is in fluid communication with the tube coupled to the signal transmitter.FIG. 4shows a graph indicating receipt of a pulsed signal by the sensor24, such as by the signal transmitter30or by a clinician tapping on the tubing set16. In response to the sensor24receiving the vibratory signal, the indicator26provides an indication to the clinician that the signal has been received. The clinician then knows that the tubing section16to which the acoustic receiver22is connected is continuous with the tubing section to which the vibratory signal is provided.

Referring now toFIG. 2, addition of the infusion pump18to the system10creates additional complications for acoustic continuity sensing. In particular, the infusion pump18may dampen the provided vibratory signal sufficiently that a signal provided on an upstream side of the pump cannot be accurately detected on a downstream side of the pump (or vice versa). One method of accommodating the dampening factor of the infusion pump18is to use a two-step process, whereby the receiver22is initially placed on the tubing set16near the catheter14, and a vibratory signal is systematically transmitted from the location13associated with each pump channel output on the downstream side of the pump or pumps (if there are multiple pumps in the infusion system), one by one, until continuity is established on the downstream side of the infusion system. This allows the clinician to determine which pump channel is associated with the tubing set16near the catheter14. Then, a vibratory signal is transmitted from the location13associated with the upstream side of the pump18on the same channel, and the receiver22is systematically moved from one tubing system to another near the medication containers12until the signal is received. This shows continuity from the medicine container12to the pump18. In this way, continuity can be established fully from the medication container12to catheter14using only a single receiver22and a single transmitter30, even with an intervening infusion pump18. This is generally referred to as a “pump out” approach because the signals are transmitted from positions proximal to the pump in both upstream and downstream directions. The system and method can be streamlined when the upstream and downstream signal transmitters30and associated software are incorporated into the pump18. In this case, only a single receiver22needs to be positioned by the clinician.

One of skill in the art will note that the above-listed steps are optionally performed in the opposite order, such that continuity from the medication container12to the pump18is determined before continuity from the pump to the catheter14, without departing from the scope of the invention. Further, artisans will appreciate that the positions of the transmitter30and receiver22could be switched to generate a “pump in” workflow, such that signals are transmitted from the catheter14and the medication container12, and received at the upstream and downstream sides of the pump18. The system and method can be streamlined when the upstream and downstream acoustic receivers22and associated software are incorporated into the pump18. In this case, only a single signal transmitter30needs to be positioned by the clinician. Further simplification is possible when finger taps are used in place of the signal transmitter30.

Similarly, a “top down” workflow uses a signal transmitted from the medicine container and received at the pump upstream side, and a signal transmitted from the pump downstream side and received at the catheter. A “bottom up” workflow uses a signal transmitted from the catheter and received at the pump downstream side and a signal transmitted from the pump upstream side and received at the medicine container. The chart below shows the positioning of the transmitters and receivers with respect to the medication container, pump upstream side, pump downstream side, and catheter:

While each of the above configurations and workflows results in the same determination of continuity, different clinicians may find certain workflows more expedient and/or more intuitive. Accordingly, a system that allows for the flexibility to determine continuity in whichever way a clinician prefers is advantageous in that it encourages the clinicians to use the equipment, reducing the propensity for errors in line tracing and increasing the speed at which a line tracing can be performed.

Another method of accommodating the dampening factor of the infusion pump18is to use a relay32. As shown inFIG. 5, the infusion system10optionally includes a relay32having the acoustic receiver22electrically coupled to the signal transmitter30via a wired or wireless connection. The relay is disposed such that the receiver and the transmitter are on opposite sides of the pump (i.e., the receiver22is disposed upstream, while the transmitter30is disposed downstream, or vice versa). Then, an acoustic signal is provided to the tubing set16on the side of the pump that includes the receiver. When the receiver22receives the provided signal, a corresponding signal is generated by the electrically coupled signal transmitter30. Thus, the dampening effect of the pump18is negated.

It is also contemplated that the signal receiver22and the signal transmitter30may communicate with one another, either wirelessly or via wired connection. In particular, the transmitter30preferably transmits information regarding one or more characteristics of the transmitted acoustic vibration to the receiver22. Such characteristics preferably include one or more of signal frequency (or range of frequencies), signal amplitude (or range of amplitudes), signal timing, a particular signal pattern to be transmitted, or other characteristics identifying the signal. This allows the receiver22to discriminate between a received signal from the transmitter30and noise or other extraneous vibrations in the tubing caused by, for example cross-talk between numerous transmitters and receivers in a complex infusion system, incidental contact between multiple tubes of an infusion system, vibrations induced by a pump18, or other sources of vibration present within system10. The receiver22compares the signal received at the sensor24with the one or more signal characteristics and, if the received signal matches the characteristics, indicates that the signal is received via the indicator26.

While the principles of the present infusion set line tracing system have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the claims following below.