The present invention has been developed in response to the above and other needs in the art. Briefly summarized, embodiments of the present invention are directed to a catheter assembly for providing intravascular access to a patient is disclosed. The catheter assembly is configured for precise placement of the catheter distal end at a desired location within the patient vasculature.
In one embodiment, the catheter assembly comprises a catheter including an elongate body that defines a proximal end, a distal end, and a lumen extending therebetween. A guidewire is also included and is configured for being received within the lumen of the catheter and for guiding the catheter through a vasculature of the patient.
The guidewire in one embodiment includes a plurality of depth markings along at least a portion of a length of the guidewire. The depth markings indicate a distance between a distal end of the guidewire and an insertion site through which the guidewire passes into the patient vasculature. Thus, when the distal end of the guidewire has been navigated to a desired location in the patient vasculature, the precise distance between the distal end and the insertion site can be readily ascertained by reading the depth marking at the insertion site. The place of the catheter can use this “depth” distance to then trim the catheter to the appropriate length before inserting into the patient. The catheter is then slid over the guidewire into the patient vasculature until the distal end of the catheter arrives at the desired location. The guidewire is then removed, and the catheter secured.
The guidewire in one embodiment further includes a modified tip at the distal end thereof that is configured for assisting in advancement of the guidewire through the vasculature. A compliant tip and a j-tip are examples of modified tips that may be employed. An orientation feature is also disposed at the proximal end of the guidewire that indicates the orientation of the modified tip. In this way, a placer of the catheter can readily determine the orientation of the tip of the guidewire within the patient by observing the external orientation feature at the guidewire proximal end.
These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Reference will now be made to figures wherein like structures will be provided with like reference designations. It is understood that the drawings are diagrammatic and schematic representations of exemplary embodiments of the invention, and are not limiting of the present invention nor are they necessarily drawn to scale.
Reference is first made to
Note that the particular configuration of the components shown in
The catheter assembly further includes a guidewire 30 employed in assisting the placement of the catheter 12 in the vasculature of a patient. As shown in
Reference is now made to
Note that, for purposes of the present disclosure, the term “guidewire” is construed herein to include any structure at least partially disposed within a vasculature of a patient and configured for reception by a lumen of a catheter or other suitable device to facilitate advancement of the catheter or other device into and/or within the vasculature of the patient.
Reference is now made to
Generally the magnetic elements 48 may include any type or form of magnetic material, including both permanent magnetic materials and electromagnetic materials. For example, in the present embodiment, the magnetic elements 48 include a rare-earth magnet (e.g., samarium cobalt and/or neodymium iron boron). In another embodiment, the magnetic elements can include an AINiCO magnetic material, a plastic magnetic material (e.g., PANiCNQ), or a ceramic magnetic material, such as barium ferrite (BaO6Fe2O3) or strontium ferrite (SrO6Fe2O3) and iron oxide (Fe3O4). In yet another embodiment, the magnetic materials can include an electromagnetic material such as a solenoid, which generates a magnetic field upon application of an electric current.
In the present embodiment, the magnetic elements 48 exhibit an observable dipole so as to provide an indication of the position and/or orientation of the magnetic elements and, therefore, the position and/or orientation of the distal region 46 of the guidewire 30. In particular, the magnetic elements 48 produce a magnetic dipole that, when the guidewire 30 is disposed within the vasculature of a patient, is detectable from outside of the patient's body using detection technology (discussed in greater detail below) to indicate the position and/or orientation of the guidewire 30 within the patient's body.
Generally speaking, the poles of the magnetic elements 48 of the guidewire 30 can be positioned or oriented in any number of ways. For example, the dipole of the magnetic elements 48 can be oriented substantially parallel to the longitudinal axis of the guidewire or substantially perpendicular to the longitudinal axis. In addition, the north pole of the magnetic elements 48, if commonly aligned, can be positioned proximate the distal end 36 of the guidewire 30, thus orienting the south pole of the magnetic elements toward the proximal end 34.
In general, any type or form of detection system may be used to detect the dipole or other aspect of the magnetic element(s) 48 to provide an indication of the position and/or orientation of the distal end 36 of the guidewire 30 when in the vasculature of a patient. Non-limiting examples of suitable detection apparatus include the various detection devices disclosed in U.S. Pat. Nos. 5,879,297, 6,129,668, 6,216,028, and 6,263,230 to Haynor et al. (“the Haynor patents”), the entirety of each of which is incorporated, in its entirety, by this reference. For example, an exemplary detection apparatus may comprise a plurality of magnetic sensors oriented in a known direction to generate a set of signals based on the strength and direction of the magnetic field generated by the magnetic element(s) of the guidewire 30. A processor may then calculate an estimated position of the magnetic elements 48 in a three-dimensional space based on the predicted and actual magnetic field strength of the magnetic material derived from the set of signals generated by the magnetic sensors. It is also appreciated that in other embodiments, an ECG-based detector may be used to detect the position of the guidewire distal end 36 with respect to the SVC or other portion of the heart, as may be appreciated by one skilled in the art.
For example, the location and/or orientation of the magnetic element(s) 48 of the guidewire 30 can be calculated by comparing the difference between the predicted magnetic field strength and the actual measured magnetic field strength of the magnetic element(s). In certain embodiments, a display connected to the processor may display the position of the magnetic material of the guidewire 30 in a three-dimensional space. Accordingly, a detection apparatus, such as the exemplary detection apparatus described herein, may detect the magnetic field generated by the magnetic material of guidewire 30 positioned within a patient's body in order to determine the position and/or orientation of at least a portion of the guidewire, such as the distal end thereof.
Note that the present embodiment contemplates use of the guidewire 30 with a catheter, such as a central venous catheter (“CVC”), or peripherally-inserted central catheter (“PICC”) to help guide the catheter 12 (
As seen in
The depth markings 50 can be placed on the guidewire 30 in one or more of a variety of ways, including via physical or chemical etching, engraving, imprinting, etc. In one embodiment, the depth markings can be disposed on the guidewire 30 so as to be radiographically observable, if desired.
In greater detail, when the guidewire 30 has been placed such that its distal end 36 is located at a desired position within the patient vasculature, such as the SVC, the depth marking 50 closest to the insertion site can be consulted to determine the distance from the insertion site to the guidewire distal end. This immediately informs the placer of the catheter how long the catheter 12 must be in order to traverse the same path through the vasculature form the insertion site in order to disposed the distal end of the catheter at the desired position. This in turn provides enhanced catheter distal tip placement accuracy.
Reference is now made to
The monitoring by the magnetic detection device confirms that the distal end 36 of the guidewire 30 arrives at a desired location within the vasculature of the patient, such as the SVC. Once the distal end 36 of the guidewire 30 is positioned at the desired location, the placer notes the depth marking 50 nearest the insertion site 54. From this depth marking, the placer is able to determine the length of catheter necessary to reach the desired location. For instance,
Once it has been cut to proper length according to the calculation of the depth marking 50 above, the catheter 12 is advanced through the insertion site 54 and over the guidewire 30 until the distal end of the catheter has reached the desired position. This will correspond to the external portion of the catheter 12 being in the desired proximity to the insertion site 54 as desired by the placer. The placer then removes the guidewire 30 and secures the catheter 12.
In another example embodiment, shown in
In one embodiment, the guidewire 30 can be pre-loaded within the lumen of the catheter 12 to form an assembly and inserted into the patient vasculature in this configuration. When inserted in this manner, the distal end 36 of the guidewire 30 corresponds to the distal end of the catheter as the assembly is advanced through the patient vasculature. Thus, when the guidewire distal region 46, including the magnetic elements 48, is detected using a magnetic detection device as being at the SVC or other desired position, the distal portion of the catheter 12 is also positioned thereat. Corresponding markers (i.e., the depth markers 50 and the markers 52) of the guidewire 30 and catheter 12 enable the distance from the insertion site 54 to the desired location to be readily ascertained. However, should an obstruction or area of difficult passage be encountered during advancement of the mated catheter 12 and guidewire 30 to the desired location, the distal end 36 of the guidewire can be temporarily advanced beyond the distal end of the catheter to enable the obstruction to be more easily traversed by the guidewire. Once the distal end of the guidewire has advanced past the obstruction to the desired location, the catheter 12 can be advanced relative to the guidewire until its distal end is also at the desired location. Again, because of the markings 52 disposed on the catheter 12 (
Reference is now made to
As shown, the compliant tip 64 includes a pre-curved portion defining a compliant bend. During advancement of the guidewire 30 through the patient vasculature, a placer can palpate or visually inspect the orientation feature 60 at the guidewire proximal region, which remains exterior to the patient. Knowing the orientation relationship between the orientation feature 60 and the compliant tip 64, the placer can easily determine the orientation of the compliant tip, thus assisting the placer in navigating the vasculature.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims the benefit of U.S. Provisional Patent Application No. 60/923,636, filed Apr. 16, 2007, and entitled “Catheter Placement System,” which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60923636 | Apr 2007 | US |