Patent Application
20190076051
The invention relates generally to a system and method for guidance of a peripherally inserted central catheter within the vasculature of a patient. More particularly, the system includes ECG signal-based catheter tip guidance, in the form of a graphical display, to enable a user to identify a P-wave and guide the catheter tip to an ideal anatomical position with respect to a node of the patient's heart from which the ECG signals originate.
Electrocardiograms may be used for monitoring peripherally inserted central catheter tip locations near the heart. Atrial and ventricular depolarization and repolarization are represented on the ECG as a series of waves: the P wave followed by the QRS complex and the T wave. The first deflection is the P wave associated with right and left atrial depolarization. In practice, a user who is positioning a peripherally inserted central catheter will monitor catheter placement on an electrocardiogram as the ECG or EKG tracks the deflection of the P wave as the catheter is advanced from the upper ⅓ of the superior vena cava down to through the lower ⅓ of the superior vena cava, and into the right atrium. Pulses from the Sinoatrial Node are detected by the PICC as it enters the superior vena cava. The impulse grows stronger as the tip advances down the vein, signified by an enlarged p-wave visible on the ECG. Passing the node causes a negative deflection in the wave, indicating to the user that the tip is positioned beyond the cava-atrial junction and into the right atrium, and should be retracted. The ideal tip position for a PICC line is between the distal superior vena cava and within one centimeter before the right atrium. The ideal tip position is referred to as the transition point between the peak of the P wave and the negative deflection.
However, ECG devices rely on subjective P wave interpretations by medical personnel that may easily be misinterpreted. The foregoing method of identifying the ideal anatomical position for the catheter tip is not suitable for all patient groups. It is well documented that obese, the young and patients with AF will not obtain a clear P wave rise. Also the presence of a pacemaker will mean that the P wave size is not affected by the PICC tip position. In addition, not all P waves exhibit the same patterns making misinterpretation of the transition point likely. Further, an abnormal P wave may preclude use of P wave interpretation entirely. Misinterpretation of the transition point may lead to malpositioning of the catheter tip with the associated risks and complications. In addition, the transition point or landing zone for the catheter tip may vary up to 5 cm.
Therefore, what is needed is a reliable system and method that allows the user to easily confirm the peak, deflection and transition points of a P wave.
The foregoing problems associate with interpreting P waves are addressed by the system and method in accordance with the invention.
In one aspect, the system and method includes a sensor that is positioned on the tip of a peripherally inserted central catheter (PICC) or in a lumen thereof.
In another aspect of the invention, the system includes a graphical display that depicts information relating to the catheter during insertion into the body. An icon or other indicia provides a graphical representation of the three-dimensional position of the catheter.
In another aspect of the invention a system for guiding the placement of a peripherally inserted central catheter is disclosed. The system broadly includes a control processor for converting a P wave signal into graphical information representative of the three-dimensional location of the catheter within the patient's body; a display that depicts the graphical information; and indicia depicted on the display that indicates a three-dimensional position of the catheter.
In another aspect the graphical representation guides the placement of a peripherally inserted central catheter making it relatively easy and intuitive to determine the ideal catheter tip location during a medical procedure without having to interpret an ECG wave form transition.
In another aspect, the simple gauge allows for ready usage in any electronic display used for catheter tip placement.
In another aspect of the invention the system includes at least one sensor capable of sensing the electrical signal associated with the P wave. The sensor is configured for attachment on the tip of the peripherally inserted central catheter or in a lumen thereof and configured to provide a waveform signal to a processing device. The waveform signal may comprise a P wave including the initial deflection, the maximum height or peak, a negative deflection and a transition point. The transition point is the point between the negative deflection and the peak and indicates correct positioning of the PICC. The system may also include a database including known data corresponding to standard and non-standard P waves including peaks, deflections and transition points thereof. A processing device is in operable communication with the sensor and the database and is configured to receive the at least one waveform signal and calculate waveform attributes of the waveform including the initial deflection of a P wave, the maximum peak, the secondary deflection and the transition point. The processing device further compares the waveform attributes with the database of known data and output a graphical representation of the maximum peak, the secondary deflection and the transition point. The system in accordance with the invention also includes a display device configured to display the output and may comprise a computer screen, a flat-screen display, a projector, a printing device and/or an audible device. The display device may also have user input device configured to communicate with the display device and the processing device.
In another aspect of the invention a method for guiding the placement of a peripherally inserted central catheter in a patient is provided. The method includes providing a peripherally inserted central catheter having a tip and a lumen therewithin; coupling at least one sensor to said catheter for sensing and transmitting an electrical signal associated with a P wave; providing a data base including known data corresponding to standard and non-standard P waves including peaks, deflections and transition points; providing a processing device for communicating with said at least one sensor and said data base, said processing device for receiving said electrical signal from said at least one sensor and identifying P waveform attributes of said signal, cross-referencing said waveform attributes and said electrical signal with known data in said base data, and outputting indicia representative of said P wave and P waveform attributes based on said cross-reference
For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
Embodiments of the present invention are generally directed to a catheter placement system configured for accurately placing a catheter within the vasculature of a patient. Referring to
ECG signal-based catheter tip guidance is included in the system in accordance with the invention that enables guidance of the catheter tip to a desired position with respect to a node of the patient's heart from which the ECG signals originate.
The catheter placement system in accordance with the invention facilitates catheter placement within the patient's vasculature with a relatively high level of accuracy, i.e., placement of the distal tip of the catheter in a predetermined and desired position. Moreover, because of the ECG-based guidance of the catheter tip, correct tip placement may be confirmed without the need for a confirmatory X-ray. This, in turn, reduces the patient's exposure to potentially harmful x-rays, the cost and time involved in transporting the patient to and from the x-ray department, costly and inconvenient catheter repositioning procedures, etc.
Referring now to
Referring now to
As the electrode attached to PICC tip is advanced further into the right atrium, the polarity of the P wave “P” changes from predominantly negative near the top of the right atrium (position C) to isoelectric (i.e., half has a positive polarity and half has a negative polarity) near the middle of the right atrium (position D) to almost entirely positive at the bottom of the right atrium (position E). Correct anatomical positioning of the catheter tip is at transition point 100 between the distal superior vena cava and within one centimeter before the right atrium.
To ensure correct placement of the catheter tip the method and system in accordance with the invention will display the peak, deflection and transition points of a P wave on display means.
Referring to
Referring now to
In one embodiment, sensor 114 may include electrodes for measuring ECG signals microphones for measuring and recording heart sounds, sensors such as sound sensors, electrocardiography sensors, optical finger sensors, optical magnetic sensors and the like. While
The processing device 112 includes non-volatile memory. The processing device computes the position and direction of the catheter tip in real form and converts the electrical signals from sensor 114 into indicia representative of the peak, deflection and transition points of the associated P wave. In one aspect, the indicia may comprise a graphical bar form, as shown, as the catheter tip progresses toward the heart. Those of skill in the art will appreciate that the bar may be vertical or horizontally placed or alternatively the graphical form may comprise a line that runs along an X and Y axis. Still yet alternatively, the gauge may be circular. In whatever representation chosen, the indicia will have a range according to the maximum QRS waveform.
The system and method in accordance with the invention determines whether a P wave is present, whether they are occurring regularly, whether the P wave is normal/standard or non-standard, whether the P waves are smooth, rounded, upright or inverted and whether the P waves have uniform or non-uniform shapes, and P wave intervals, which shorten with increased heart rate, including whether they are constant or vary.
The system includes at least one sensor capable of sensing the electrical signal associated with the P wave. The sensor is configured for attachment on the tip of the peripherally inserted central catheter or in a lumen thereof and configured to provide a waveform signal to a processing device. The waveform signal may comprise a P wave including the initial deflection, the maximum height or peak, a negative deflection and a transition point. The transition point is the point between the negative deflection and the peak and indicates correct positioning of the PICC. The system also includes a database including known data corresponding to standard and non-standard P waves including peaks, deflections and transition points thereof. A processing device is in operable communication with the sensor and the database and is configured to receive the at least one waveform signal and calculate waveform attributes of the waveform including the initial deflection of a P wave, the maximum peak, the secondary deflection and the transition point. The processing device further compares the waveform attributes with the database of known data and output a graphical representation of the maximum peak, the secondary deflection and the transition point. The system in accordance with the invention also includes a display device configured to display the output and may comprise a computer screen, a flat-screen display, a projector, a printing device and/or an audible device. The display device may also have user input device configured to communicate with the display device and the processing device.
The database may also include a plurality of waveforms and waveform attributes such as P waves, QRS complex, PR intervals, PR segments, AT intervals, ST segment and the T wave.
The computing system may be operative to generate indicia representing a real time image of the P wave.
As seen in
The bar graph may be colored and progress from zero and increase as the P wave increases towards the right atrium. When the processing device 112 detects the negative deflection of the P wave the color of the bar may change indicating to a user that the deflection is increasing. The colors may be red and green but those of skill in the art will appreciate that any color combination may be used. The catheter tip can then be retracted to the maximum P wave position and the ideal anatomic infusion location of the patient.
It will be appreciated by those skilled in the art that changes could be made to the embodiment described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
